diff --git a/BUILD b/BUILD.bazel
similarity index 100%
rename from BUILD
rename to BUILD.bazel
diff --git a/docs/development/how_to_debug.rst b/docs/development/how_to_debug.rst
index ea4688585562d812d06cdfa4a27935f3252df66a..a28029da2d57d976883a98f16b9b99e38d70a97d 100644
--- a/docs/development/how_to_debug.rst
+++ b/docs/development/how_to_debug.rst
@@ -101,17 +101,22 @@ MACE also provides model visualization HTML generated in `builds` directory, gen
 
 Debug engine using log
 --------------------------
-Mace defines two sorts of logs: one is for users (LOG), the other is for developers (VLOG).
+MACE implements a similar logging mechanism like `glog <https://github.com/google/glog>`__.
+There are two types of logs, LOG for normal logging and VLOG for debugging.
 
-LOG includes four levels, i.e, ``INFO``, ``WARNING``, ``ERROR``, ``FATAL``;
-Environment variable ``MACE_CPP_MIN_LOG_LEVEL`` can be set to specify log level of users, e.g.,
-``set MACE_CPP_MIN_LOG_LEVEL=0`` will enable ``INFO`` log level, while ``set MACE_CPP_MIN_LOG_LEVEL=4`` will enable ``FATAL`` log level.
+LOG includes four levels, sorted by severity level: ``INFO``, ``WARNING``, ``ERROR``, ``FATAL``.
+The logging severity threshold can be configured via environment variable, e.g. ``MACE_CPP_MIN_LOG_LEVEL=WARNING`` to set as ``WARNING``.
+Only the log messages with equal or above the specified severity threshold will be printed, the default threshold is ``INFO``.
+We don't support integer log severity value like `glog <https://github.com/google/glog>`__, because they are confusing with VLOG.
 
+VLOG is verbose logging which is logged as ``LOG(INFO)``. VLOG also has more detailed integer verbose levels, like 0, 1, 2, 3, etc.
+The threshold can be configured through environment variable, e.g. ``MACE_CPP_MIN_VLOG_LEVEL=2`` to set as ``2``.
+With VLOG, the lower the verbose level, the more likely messages are to be logged. For example, when the threshold is set
+to 2, both ``VLOG(1)``, ``VLOG(2)`` log messages will be printed, but ``VLOG(3)`` and highers won't. 
 
-VLOG level is specified by numbers, e.g., 0, 1, 2. Environment variable ``MACE_CPP_MIN_VLOG_LEVEL`` can be set to specify vlog level.
-Logs with higher levels than which is specified will be printed. So simply specifying a very large level number will make all logs printed.
+All expensive logging with ``VLOG`` should be guarded with ``if(VLOG_IS_ON(lvl))`` check to avoid normal run overhead.
 
-By using Mace run tool, vlog level can be easily set by option, e.g.,
+By using ``mace_run`` tool, VLOG level can be easily set by option, e.g.,
 
 	.. code:: sh
 
@@ -168,9 +173,3 @@ things may be a little bit complicated.
 		# then you can use it as host gdb, e.g.,
 		bt
 
-
-
-
-
-
-
diff --git a/mace/BUILD b/mace/BUILD.bazel
similarity index 86%
rename from mace/BUILD
rename to mace/BUILD.bazel
index 4b7da51fccfac614fe845bdd95e58d960c62ed75..77e2c532ec7bb563a17af07e9fab1cfce27be58a 100644
--- a/mace/BUILD
+++ b/mace/BUILD.bazel
@@ -6,6 +6,22 @@ config_setting(
     visibility = ["//visibility:public"],
 )
 
+config_setting(
+    name = "linux",
+    define_values = {
+        "linux": "true",
+    },
+    visibility = ["//visibility:public"],
+)
+
+config_setting(
+    name = "darwin",
+    define_values = {
+        "darwin": "true",
+    },
+    visibility = ["//visibility:public"],
+)
+
 config_setting(
     name = "android_armv7",
     values = {
diff --git a/mace/benchmark/BUILD b/mace/benchmark/BUILD.bazel
similarity index 100%
rename from mace/benchmark/BUILD
rename to mace/benchmark/BUILD.bazel
diff --git a/mace/benchmark/benchmark_model.cc b/mace/benchmark/benchmark_model.cc
index 666840e9fe31877d04b7197871775a7b3ed0f3c6..b0370321967f45f3698d83d446b32a63e1be2f39 100644
--- a/mace/benchmark/benchmark_model.cc
+++ b/mace/benchmark/benchmark_model.cc
@@ -23,7 +23,7 @@
 #include "gflags/gflags.h"
 #include "mace/public/mace.h"
 #include "mace/utils/logging.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #include "mace/benchmark/statistics.h"
 #ifdef MODEL_GRAPH_FORMAT_CODE
 #include "mace/codegen/engine/mace_engine_factory.h"
diff --git a/mace/benchmark/model_throughput_test.cc b/mace/benchmark/model_throughput_test.cc
index 66b178cf7178919adf57d064f2aa21ccee0dc491..cdc4639155cdab36f45eb038907e7ac71e069f2e 100644
--- a/mace/benchmark/model_throughput_test.cc
+++ b/mace/benchmark/model_throughput_test.cc
@@ -23,8 +23,7 @@
  *          --dsp_model_data_file=dsp_model_data.data \
  *          --run_seconds=10
  */
-#include <malloc.h>
-#include <stdint.h>
+#include <cstdint>
 #include <cstdlib>
 #include <fstream>
 #include <iostream>
@@ -33,7 +32,7 @@
 
 #include "gflags/gflags.h"
 #include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 #include "mace/core/types.h"
 
diff --git a/mace/codegen/BUILD b/mace/codegen/BUILD.bazel
similarity index 100%
rename from mace/codegen/BUILD
rename to mace/codegen/BUILD.bazel
diff --git a/mace/core/BUILD b/mace/core/BUILD.bazel
similarity index 96%
rename from mace/core/BUILD
rename to mace/core/BUILD.bazel
index 2e37524ffd8a77e400ba2924cd656586744b3af3..14ddc6b6cfe215497d32b9a5509a3cc1835ea7a6 100644
--- a/mace/core/BUILD
+++ b/mace/core/BUILD.bazel
@@ -59,14 +59,12 @@ cc_library(
     ]) + if_neon_enabled([
         "-DMACE_ENABLE_NEON",
     ]),
-    linkopts = ["-ldl"] + if_android([
-        "-pie",
-        "-lm",
-    ]),
+    linkopts = ["-ldl"],
     deps = [
         "//mace/codegen:generated_version",
         "//mace/proto:mace_cc",
         "//mace/utils",
+        "//mace/port",
         "@half//:half",
     ] + if_opencl_enabled([
         ":opencl_headers",
diff --git a/mace/core/allocator.h b/mace/core/allocator.h
index 9c9103635245921ca2c354702b8ec9b062c40f37..c7499b92b51053436e61edabf4c93069c93f7a81 100644
--- a/mace/core/allocator.h
+++ b/mace/core/allocator.h
@@ -15,14 +15,13 @@
 #ifndef MACE_CORE_ALLOCATOR_H_
 #define MACE_CORE_ALLOCATOR_H_
 
-#include <stdlib.h>
-#include <string.h>
+#include <cstdlib>
 #include <map>
 #include <limits>
 #include <vector>
 #include <cstring>
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/core/types.h"
 #include "mace/core/runtime_failure_mock.h"
 #include "mace/public/mace.h"
diff --git a/mace/core/buffer.h b/mace/core/buffer.h
index ca7ada06f4c2d31eb497a968d842ccb2064a1937..418da27d95f01764659dde9515353d1d80ba4bca 100644
--- a/mace/core/buffer.h
+++ b/mace/core/buffer.h
@@ -21,8 +21,9 @@
 #include <functional>
 
 #include "mace/core/allocator.h"
-#include "mace/core/macros.h"
 #include "mace/core/types.h"
+#include "mace/utils/logging.h"
+#include "mace/utils/macros.h"
 
 namespace mace {
 namespace core {
diff --git a/mace/core/future.h b/mace/core/future.h
index 13382e1bf84575f2b0e5e63b0d881d720fc0e5d9..c7227d4df6ade05b1a6d392de0dbfa4772dff39d 100644
--- a/mace/core/future.h
+++ b/mace/core/future.h
@@ -20,11 +20,10 @@
 #include <vector>
 
 #include "mace/utils/logging.h"
+#include "mace/public/mace.h"
 
 namespace mace {
 
-struct CallStats;
-
 // Wait the call to finish and get the stats if param is not nullptr
 struct StatsFuture {
   std::function<void(CallStats *)> wait_fn = [](CallStats *stats) {
diff --git a/mace/core/kv_storage.cc b/mace/core/kv_storage.cc
index 5eba8567171bba82b6f2e9d2bef094b5614490e8..e2feb8c827b5939098eb0b7d3a451b1ad62b44a6 100644
--- a/mace/core/kv_storage.cc
+++ b/mace/core/kv_storage.cc
@@ -13,18 +13,18 @@
 // limitations under the License.
 
 #include <fcntl.h>
-#include <limits.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include <climits>
 #include <algorithm>
 #include <cstring>
 #include <memory>
 #include <utility>
 
 #include "mace/core/kv_storage.h"
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/core/memory_optimizer.cc b/mace/core/memory_optimizer.cc
index 0b448ac97c508cbc4786823d8318750db3e683d0..f2afdaa7de3e408b91a55aef46c97d4597e4ce26 100644
--- a/mace/core/memory_optimizer.cc
+++ b/mace/core/memory_optimizer.cc
@@ -21,8 +21,9 @@
 #include <unordered_set>
 
 #include "mace/core/arg_helper.h"
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/utils/logging.h"
+#include "mace/public/mace.h"
 
 #ifdef MACE_ENABLE_OPENCL
 #include "mace/core/runtime/opencl/opencl_util.h"
diff --git a/mace/core/net.cc b/mace/core/net.cc
index 4bcbbb70e5378ff1dd76620e1dedcc61831dd48d..365bb353e6de3d5872e2ac75965183b403a09890 100644
--- a/mace/core/net.cc
+++ b/mace/core/net.cc
@@ -19,14 +19,16 @@
 #include <utility>
 
 #include "mace/core/future.h"
-#include "mace/core/macros.h"
 #include "mace/core/memory_optimizer.h"
 #include "mace/core/net.h"
 #include "mace/core/op_context.h"
 #include "mace/public/mace.h"
-#include "mace/utils/memory_logging.h"
+#include "mace/port/env.h"
+#include "mace/utils/conf_util.h"
+#include "mace/utils/logging.h"
+#include "mace/utils/macros.h"
+#include "mace/utils/math.h"
 #include "mace/utils/timer.h"
-#include "mace/utils/utils.h"
 
 #ifdef MACE_ENABLE_OPENCL
 #include "mace/core/runtime/opencl/opencl_util.h"
@@ -114,9 +116,8 @@ std::unique_ptr<Operation> SerialNet::CreateOperation(
       }
     }
   }
-  std::unique_ptr<Operation> op(
-      op_registry->CreateOperation(construct_context, device_type));
-  return std::move(op);
+
+  return op_registry->CreateOperation(construct_context, device_type);
 }
 
 SerialNet::SerialNet(const OpRegistryBase *op_registry,
@@ -148,15 +149,14 @@ SerialNet::SerialNet(const OpRegistryBase *op_registry,
       continue;
     }
     for (int i = 0; i < op.output_size(); ++i) {
-      tensor_shape_map[op.output(i)] =
-          std::move(std::vector<index_t>(op.output_shape(i).dims().begin(),
-                                         op.output_shape(i).dims().end()));
+      tensor_shape_map[op.output(i)] = std::vector<index_t>(
+          op.output_shape(i).dims().begin(),
+          op.output_shape(i).dims().end());
     }
   }
   for (auto &tensor : net_def->tensors()) {
     tensor_shape_map[tensor.name()] =
-        std::move(std::vector<index_t>(tensor.dims().begin(),
-                                       tensor.dims().end()));
+      std::vector<index_t>(tensor.dims().begin(), tensor.dims().end());
   }
 
   bool has_data_format = false;
@@ -468,7 +468,7 @@ MaceStatus SerialNet::Run(RunMetadata *run_metadata) {
     VLOG(3) << "Operator " << op->debug_def().name()
             << " has shape: " << MakeString(op->Output(0)->shape());
 
-    if (EnvEnabled("MACE_LOG_TENSOR_RANGE")) {
+    if (EnvConfEnabled("MACE_LOG_TENSOR_RANGE")) {
       for (int i = 0; i < op->OutputSize(); ++i) {
         if (op->debug_def().quantize_info_size() == 0) {
           int data_type = op->GetOptionalArg("T", static_cast<int>(DT_FLOAT));
diff --git a/mace/core/runtime/cpu/cpu_runtime.cc b/mace/core/runtime/cpu/cpu_runtime.cc
index c4ed389265a9881fd6505476ffe45f5852f1bc15..34255e565460cd2958aabb80cfcd5b10ebc147e8 100644
--- a/mace/core/runtime/cpu/cpu_runtime.cc
+++ b/mace/core/runtime/cpu/cpu_runtime.cc
@@ -18,9 +18,6 @@
 #include <omp.h>
 #endif
 
-#include <unistd.h>
-#include <sys/syscall.h>
-#include <sys/types.h>
 #include <algorithm>
 #include <cerrno>
 #include <cstring>
@@ -29,8 +26,9 @@
 #include <utility>
 #include <vector>
 
-#include "mace/core/macros.h"
+#include "mace/port/env.h"
 #include "mace/public/mace.h"
+#include "mace/utils/macros.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
@@ -44,86 +42,15 @@ struct CPUFreq {
 
 namespace {
 
-int GetCPUCount() {
-  int cpu_count = 0;
-  std::string cpu_sys_conf = "/proc/cpuinfo";
-  std::ifstream f(cpu_sys_conf);
-  if (!f.is_open()) {
-    LOG(ERROR) << "failed to open " << cpu_sys_conf;
-    return -1;
-  }
-  std::string line;
-  const std::string processor_key = "processor";
-  while (std::getline(f, line)) {
-    if (line.size() >= processor_key.size()
-        && line.compare(0, processor_key.size(), processor_key) == 0) {
-      ++cpu_count;
-    }
-  }
-  if (f.bad()) {
-    LOG(ERROR) << "failed to read " << cpu_sys_conf;
-  }
-  if (!f.eof()) {
-    LOG(ERROR) << "failed to read end of " << cpu_sys_conf;
-  }
-  f.close();
-  VLOG(2) << "CPU cores: " << cpu_count;
-  return cpu_count;
-}
-
-int GetCPUMaxFreq(std::vector<float> *max_freqs) {
-  int cpu_count = GetCPUCount();
-  for (int cpu_id = 0; cpu_id < cpu_count; ++cpu_id) {
-    std::string cpuinfo_max_freq_sys_conf = MakeString(
-        "/sys/devices/system/cpu/cpu",
-        cpu_id,
-        "/cpufreq/cpuinfo_max_freq");
-    std::ifstream f(cpuinfo_max_freq_sys_conf);
-    if (!f.is_open()) {
-      LOG(ERROR) << "failed to open " << cpuinfo_max_freq_sys_conf;
-      return -1;
-    }
-    std::string line;
-    if (std::getline(f, line)) {
-      float freq = strtof(line.c_str(), nullptr);
-      max_freqs->push_back(freq);
-    }
-    if (f.bad()) {
-      LOG(ERROR) << "failed to read " << cpuinfo_max_freq_sys_conf;
-    }
-    f.close();
-  }
-
-  for (float freq : *max_freqs) {
-    VLOG(2) << "CPU freq: " << freq;
-  }
-
-  return 0;
-}
-
-MaceStatus SetThreadAffinity(cpu_set_t mask) {
-#if defined(__ANDROID__)
-  pid_t pid = gettid();
-#else
-  pid_t pid = syscall(SYS_gettid);
-#endif
-  int err = sched_setaffinity(pid, sizeof(mask), &mask);
-  if (err) {
-    LOG(WARNING) << "set affinity error: " << strerror(errno);
-    return MaceStatus(MaceStatus::MACE_INVALID_ARGS,
-                      "set affinity error: " + std::string(strerror(errno)));
-  } else {
-    return MaceStatus::MACE_SUCCESS;
-  }
-}
-
 MaceStatus SetOpenMPThreadsAndAffinityCPUs(int omp_num_threads,
                                            const std::vector<size_t> &cpu_ids) {
   MaceOpenMPThreadCount = omp_num_threads;
 
 #ifdef MACE_ENABLE_OPENMP
-  VLOG(1) << "Set OpenMP threads number: " << omp_num_threads
-          << ", CPU core IDs: " << MakeString(cpu_ids);
+  if (VLOG_IS_ON(1)) {
+    VLOG(1) << "Set OpenMP threads number: " << omp_num_threads
+            << ", CPU core IDs: " << MakeString(cpu_ids);
+  }
   omp_set_schedule(omp_sched_guided, 1);
   omp_set_num_threads(omp_num_threads);
 #else
@@ -131,12 +58,6 @@ MaceStatus SetOpenMPThreadsAndAffinityCPUs(int omp_num_threads,
   LOG(WARNING) << "Set OpenMP threads number failed: OpenMP not enabled.";
 #endif
 
-  // compute mask
-  cpu_set_t mask;
-  CPU_ZERO(&mask);
-  for (auto cpu_id : cpu_ids) {
-    CPU_SET(cpu_id, &mask);
-  }
 #ifdef MACE_ENABLE_OPENMP
   std::vector<MaceStatus> status(omp_num_threads,
                                  MaceStatus::MACE_INVALID_ARGS);
@@ -144,7 +65,7 @@ MaceStatus SetOpenMPThreadsAndAffinityCPUs(int omp_num_threads,
   for (int i = 0; i < omp_num_threads; ++i) {
     VLOG(1) << "Set affinity for OpenMP thread " << omp_get_thread_num()
             << "/" << omp_get_num_threads();
-    status[i] = SetThreadAffinity(mask);
+    status[i] = SchedSetAffinity(cpu_ids);
   }
   for (int i = 0; i < omp_num_threads; ++i) {
     if (status[i] != MaceStatus::MACE_SUCCESS)
@@ -152,8 +73,10 @@ MaceStatus SetOpenMPThreadsAndAffinityCPUs(int omp_num_threads,
   }
   return MaceStatus::MACE_SUCCESS;
 #else
-  MaceStatus status = SetThreadAffinity(mask);
-  VLOG(1) << "Set affinity without OpenMP: " << mask.__bits[0];
+  MaceStatus status = SchedSetAffinity(cpu_ids);
+  if (VLOG_IS_ON(1)) {
+    VLOG(1) << "Set affinity without OpenMP: " << MakeString(cpu_ids);
+  }
   return status;
 #endif
 }
@@ -166,8 +89,9 @@ MaceStatus CPURuntime::SetOpenMPThreadsAndAffinityPolicy(
     void *gemm_context) {
   // get cpu frequency info
   std::vector<float> cpu_max_freqs;
-  if (GetCPUMaxFreq(&cpu_max_freqs) == -1 || cpu_max_freqs.size() == 0) {
-    return MaceStatus::MACE_INVALID_ARGS;
+  MACE_RETURN_IF_ERROR(GetCpuMaxFreq(&cpu_max_freqs));
+  if (cpu_max_freqs.empty()) {
+    return MaceStatus::MACE_RUNTIME_ERROR;
   }
 
   std::vector<CPUFreq> cpu_freq(cpu_max_freqs.size());
diff --git a/mace/core/runtime/cpu/cpu_runtime.h b/mace/core/runtime/cpu/cpu_runtime.h
index 95fee27f5424eeed2f29eb782bd085115ab430c9..bb97267f67f46f1bb47b1729d162985b055418f7 100644
--- a/mace/core/runtime/cpu/cpu_runtime.h
+++ b/mace/core/runtime/cpu/cpu_runtime.h
@@ -22,7 +22,7 @@
 #include "public/gemmlowp.h"
 #endif  // MACE_ENABLE_QUANTIZE
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/public/mace.h"
 #include "mace/utils/logging.h"
 
diff --git a/mace/core/runtime/hexagon/hexagon_control_wrapper.cc b/mace/core/runtime/hexagon/hexagon_control_wrapper.cc
index e19d98c7805c5037f621e60469f5600118663d05..b39bfeed2510ab10f401fe653ac3ad919e8b2619 100644
--- a/mace/core/runtime/hexagon/hexagon_control_wrapper.cc
+++ b/mace/core/runtime/hexagon/hexagon_control_wrapper.cc
@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include <sys/time.h>
 #include <algorithm>
 #include <iomanip>
 #include <thread>  // NOLINT(build/c++11)
@@ -24,16 +23,9 @@
 #include "mace/core/runtime/hexagon/hexagon_control_wrapper.h"
 #include "mace/core/runtime/hexagon/hexagon_nn_ops.h"
 #include "mace/core/types.h"
+#include "mace/port/env.h"
 #include "mace/utils/quantize.h"
 
-namespace {
-inline int64_t NowMicros() {
-  struct timeval tv;
-  gettimeofday(&tv, nullptr);
-  return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
-}
-}
-
 namespace mace {
 
 #define MACE_MAX_NODE 2048
diff --git a/mace/core/runtime/opencl/opencl_runtime.cc b/mace/core/runtime/opencl/opencl_runtime.cc
index 31cd5a541ee809d53f065e9ef63c67d819963c5f..0a5f9460f1026670224dfa28738cca15486a206e 100644
--- a/mace/core/runtime/opencl/opencl_runtime.cc
+++ b/mace/core/runtime/opencl/opencl_runtime.cc
@@ -24,7 +24,7 @@
 #include <vector>
 #include <utility>
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/core/kv_storage.h"
 #include "mace/core/runtime/opencl/opencl_extension.h"
 #include "mace/utils/tuner.h"
@@ -273,7 +273,7 @@ OpenCLRuntime::OpenCLRuntime(
     gpu_type_(UNKNOWN) {
   std::vector<cl::Platform> all_platforms;
   cl::Platform::get(&all_platforms);
-  if (all_platforms.size() == 0) {
+  if (all_platforms.empty()) {
     LOG(ERROR) << "No OpenCL platforms found";
     return;
   }
@@ -289,7 +289,7 @@ OpenCLRuntime::OpenCLRuntime(
   // get default device (CPUs, GPUs) of the default platform
   std::vector<cl::Device> all_devices;
   default_platform.getDevices(CL_DEVICE_TYPE_ALL, &all_devices);
-  if (all_devices.size() == 0) {
+  if (all_devices.empty()) {
     LOG(ERROR) << "No OpenCL devices found";
     return;
   }
diff --git a/mace/core/runtime/opencl/opencl_util.cc b/mace/core/runtime/opencl/opencl_util.cc
index ff409e571bab3d92febd5cd8918c9ca4072d40cb..7aecf6f115fd8d327c5c793cba2986553ded4061 100644
--- a/mace/core/runtime/opencl/opencl_util.cc
+++ b/mace/core/runtime/opencl/opencl_util.cc
@@ -17,6 +17,7 @@
 #include <utility>
 
 #include "mace/utils/logging.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/core/testing/test_benchmark.cc b/mace/core/testing/test_benchmark.cc
index 03442869230066d081bef599d74d277283d386f0..a7cd149579bc6d6bf875a7b993010d6243a4d49a 100644
--- a/mace/core/testing/test_benchmark.cc
+++ b/mace/core/testing/test_benchmark.cc
@@ -20,7 +20,7 @@
 #include <vector>
 
 #include "mace/core/testing/test_benchmark.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/examples/cli/BUILD b/mace/examples/cli/BUILD.bazel
similarity index 100%
rename from mace/examples/cli/BUILD
rename to mace/examples/cli/BUILD.bazel
diff --git a/mace/libmace/BUILD b/mace/libmace/BUILD.bazel
similarity index 67%
rename from mace/libmace/BUILD
rename to mace/libmace/BUILD.bazel
index 1cecc7f60f86ca15904d40eb57188a2e42a83006..2dba327be5edb4623f8b2ff61a2b25c245b2e1a4 100644
--- a/mace/libmace/BUILD
+++ b/mace/libmace/BUILD.bazel
@@ -10,13 +10,13 @@ licenses(["notice"])  # Apache 2.0
 load(
     "//mace:mace.bzl",
     "if_android",
+    "if_linux",
+    "if_darwin",
     "if_neon_enabled",
-    "if_neon_enabled_str",
     "if_openmp_enabled",
     "if_android_armv7",
     "if_hexagon_enabled",
     "if_opencl_enabled",
-    "if_opencl_enabled_str",
     "if_quantize_enabled",
 )
 
@@ -77,6 +77,7 @@ cc_library(
     visibility = ["//visibility:public"],
 )
 
+# For details, see https://github.com/bazelbuild/bazel/issues/5200
 genrule(
     name = "libmace_static",
     srcs = [
@@ -87,10 +88,18 @@ genrule(
         "//mace/ops:internal_ops",
         "//mace/ops",
         "//mace/libmace",
+        "//mace/port:port_base",
+        "//mace/port/posix:port_posix",
         "//mace/utils",
         "//mace/proto:mace_cc",
         "@com_google_protobuf//:protobuf_lite",
-    ] + if_opencl_enabled([
+    ] + if_android([
+        "//mace/port/android:port_android",
+    ]) + if_linux([
+        "//mace/port/linux:port_linux",
+    ]) + if_darwin([
+        "//mace/port/darwin:port_darwin",
+    ]) + if_opencl_enabled([
         "//mace/ops:opencl_kernels",
         "//mace/codegen:generated_opencl",
     ]) + if_neon_enabled([
@@ -103,20 +112,43 @@ genrule(
           "$(locations //mace/core:core) " +
           "$(locations //mace/ops:common) " +
           "$(locations //mace/ops:ref_kernels) " +
-          if_neon_enabled_str("$(locations //mace/ops:arm_neon_kernels) ") +
-          if_opencl_enabled_str("$(locations //mace/ops:opencl_kernels) ") +
+          if_neon_enabled(
+              "$(locations //mace/ops:arm_neon_kernels) ",
+              default_value = "",
+          ) +
+          if_opencl_enabled(
+              "$(locations //mace/ops:opencl_kernels) ",
+              default_value = "",
+          ) +
           "$(locations //mace/ops:internal_ops) " +
           "$(locations //mace/ops:ops) " +
           "$(locations //mace/libmace:libmace) " +
+          "$(locations //mace/port:port_base) " +
+          "$(locations //mace/port/posix:port_posix) " +
+          if_android(
+              "$(locations //mace/port/android:port_android) ",
+              default_value = "",
+          ) +
+          if_linux(
+              "$(locations //mace/port/linux:port_linux) ",
+              default_value = "",
+          ) +
+          if_darwin(
+              "$(locations //mace/port/darwin:port_darwin) ",
+              default_value = "",
+          ) +
           "$(locations //mace/utils:utils) " +
           "$(locations //mace/proto:mace_cc) " +
           "$(locations @com_google_protobuf//:protobuf_lite) " +
-          if_opencl_enabled_str("$(locations //mace/codegen:generated_opencl) ") +
+          if_opencl_enabled(
+              "$(locations //mace/codegen:generated_opencl) ",
+              default_value = "",
+          ) +
           "$@ " +
           "$$tmp_mri_file);" +
           "$(AR) -M <$$tmp_mri_file;" +
-          "rm -rf $$tmp_mri_file;" +
-          "$(STRIP) -x $@;",
+          "rm -rf $$tmp_mri_file;",
+    # "$(STRIP) -x $@;",  # FIXME this will crash
     tools = ["//mace/python/tools:archive_static_lib"],
     visibility = ["//visibility:public"],
 )
diff --git a/mace/libmace/mace.cc b/mace/libmace/mace.cc
index 2d0acb450aadf9d60b285e4fb71a748c1870fa4f..78991a71c74f206abdfe4cf8d547b2fd6d6b2826 100644
--- a/mace/libmace/mace.cc
+++ b/mace/libmace/mace.cc
@@ -21,7 +21,12 @@
 #include "mace/core/net.h"
 #include "mace/ops/ops_registry.h"
 #include "mace/ops/common/transpose.h"
+#include "mace/utils/math.h"
+#include "mace/utils/memory.h"
+#include "mace/utils/stl_util.h"
 #include "mace/public/mace.h"
+#include "mace/port/env.h"
+#include "mace/port/file_system.h"
 
 #ifdef MACE_ENABLE_OPENCL
 #include "mace/core/runtime/opencl/gpu_device.h"
@@ -33,8 +38,6 @@
 #include "mace/core/runtime/hexagon/hexagon_device.h"
 #endif  // MACE_ENABLE_HEXAGON
 
-#include "mace/utils/memory.h"
-
 namespace mace {
 namespace {
 
@@ -377,8 +380,7 @@ class MaceEngine::Impl {
                              std::pair<const std::string, MaceTensor> *output);
 
  private:
-  const unsigned char *model_data_;
-  size_t model_data_size_;
+  std::unique_ptr<port::ReadOnlyMemoryRegion> model_data_;
   std::unique_ptr<OpRegistryBase> op_registry_;
   DeviceType device_type_;
   std::unique_ptr<Device> device_;
@@ -396,7 +398,6 @@ class MaceEngine::Impl {
 
 MaceEngine::Impl::Impl(const MaceEngineConfig &config)
     : model_data_(nullptr),
-      model_data_size_(0),
       op_registry_(new OpRegistry),
       device_type_(config.impl_->device_type()),
       device_(nullptr),
@@ -490,7 +491,7 @@ MaceStatus MaceEngine::Impl::Init(
     MACE_CHECK(hexagon_controller_->Config(), "hexagon config error");
     MACE_CHECK(hexagon_controller_->Init(), "hexagon init error");
     hexagon_controller_->SetDebugLevel(
-        static_cast<int>(mace::logging::LogMessage::MinVLogLevel()));
+        static_cast<int>(mace::port::MinVLogLevelFromEnv()));
     MACE_CHECK(hexagon_controller_->SetupGraph(*net_def, model_data),
                "hexagon setup graph error");
     if (VLOG_IS_ON(2)) {
@@ -532,23 +533,22 @@ MaceStatus MaceEngine::Impl::Init(
     const std::string &model_data_file) {
   LOG(INFO) << "Loading Model Data";
 
-  MemoryMap(model_data_file, &model_data_, &model_data_size_);
+  auto fs = GetFileSystem();
+  MACE_RETURN_IF_ERROR(fs->NewReadOnlyMemoryRegionFromFile(
+        model_data_file.c_str(), &model_data_));
 
-  MACE_RETURN_IF_ERROR(Init(net_def, input_nodes, output_nodes, model_data_));
+  MACE_RETURN_IF_ERROR(Init(net_def, input_nodes, output_nodes,
+        reinterpret_cast<const unsigned char *>(model_data_->data())));
 
   if (device_type_ == DeviceType::GPU || device_type_ == DeviceType::HEXAGON ||
       (device_type_ == DeviceType::CPU && ws_->diffused_buffer())) {
-    MemoryUnMap(model_data_, model_data_size_);
-    model_data_ = nullptr;
+    model_data_.reset();
   }
   return MaceStatus::MACE_SUCCESS;
 }
 
 MaceEngine::Impl::~Impl() {
   LOG(INFO) << "Destroying MaceEngine";
-  if (model_data_ != nullptr) {
-    MemoryUnMap(model_data_, model_data_size_);
-  }
 #ifdef MACE_ENABLE_HEXAGON
   if (device_type_ == HEXAGON) {
     if (VLOG_IS_ON(2)) {
diff --git a/mace/mace.bzl b/mace/mace.bzl
index 2afe4560e323d2ad1cbe731832c5a918b09b177b..ee9f8c59dc94ab15dd0749205c4630ce9f4b1ce4 100644
--- a/mace/mace.bzl
+++ b/mace/mace.bzl
@@ -1,15 +1,21 @@
 # -*- Python -*-
 
-def if_android(a):
+def if_android(a, default_value = []):
   return select({
       "//mace:android": a,
-      "//conditions:default": [],
+      "//conditions:default": default_value,
   })
 
-def if_not_android(a):
+def if_linux(a, default_value = []):
   return select({
-      "//mace:android": [],
-      "//conditions:default": a,
+      "//mace:linux": a,
+      "//conditions:default": default_value,
+  })
+
+def if_darwin(a, default_value = []):
+  return select({
+      "//mace:darwin": a,
+      "//conditions:default": default_value,
   })
 
 def if_android_armv7(a):
@@ -36,16 +42,10 @@ def if_arm_linux_armhf(a):
       "//conditions:default": []
   })
 
-def if_neon_enabled(a):
+def if_neon_enabled(a, default_value = []):
   return select({
       "//mace:neon_enabled": a,
-      "//conditions:default": [],
-  })
-
-def if_neon_enabled_str(a):
-  return select({
-      "//mace:neon_enabled": a,
-      "//conditions:default": "",
+      "//conditions:default": default_value,
   })
 
 def if_hexagon_enabled(a):
@@ -66,16 +66,10 @@ def if_openmp_enabled(a):
       "//conditions:default": [],
   })
 
-def if_opencl_enabled(a):
-  return select({
-      "//mace:opencl_enabled": a,
-      "//conditions:default": [],
-  })
-
-def if_opencl_enabled_str(a):
+def if_opencl_enabled(a, default_value = []):
   return select({
       "//mace:opencl_enabled": a,
-      "//conditions:default": "",
+      "//conditions:default": default_value,
   })
 
 def if_quantize_enabled(a):
diff --git a/mace/ops/BUILD b/mace/ops/BUILD.bazel
similarity index 95%
rename from mace/ops/BUILD
rename to mace/ops/BUILD.bazel
index aa434203db3da0eeb6be83c3e0538b3b76551fbe..bbf5f34822b734eb6555702cc219454bcf4ec051 100644
--- a/mace/ops/BUILD
+++ b/mace/ops/BUILD.bazel
@@ -54,34 +54,14 @@ cc_library(
 
 cc_library(
     name = "testing",
-    srcs = glob(
-        [
-            "testing/*.cc",
-        ],
-    ),
-    hdrs = glob(
-        [
-            "testing/*.h",
-        ],
-    ),
+    hdrs = [
+            "testing/test_utils.h",
+    ],
     copts = [
         "-Werror",
         "-Wextra",
         "-Wno-missing-field-initializers",
-    ] + if_openmp_enabled([
-        "-fopenmp",
-    ]) + if_neon_enabled([
-        "-DMACE_ENABLE_NEON",
-    ]) + if_android_armv7([
-        "-mfpu=neon",
-        "-mfloat-abi=softfp",
-    ]) + if_opencl_enabled([
-        "-DMACE_ENABLE_OPENCL",
-    ]) + if_quantize_enabled([
-        "-DMACE_ENABLE_QUANTIZE",
-    ]) + if_hexagon_enabled([
-        "-DMACE_ENABLE_HEXAGON",
-    ]),
+    ],
     deps = [
         "//mace/core",
         "@gtest",
diff --git a/mace/ops/arm/conv_2d_neon_15x1.cc b/mace/ops/arm/conv_2d_neon_15x1.cc
index 8523e494cebf92e359b0d53c9a3e2a7ab8cc2fcb..5cd58fcca5f9348cdfb1062c4864ed7ad65fb02c 100644
--- a/mace/ops/arm/conv_2d_neon_15x1.cc
+++ b/mace/ops/arm/conv_2d_neon_15x1.cc
@@ -17,7 +17,7 @@
 #endif
 
 #include "mace/ops/arm/conv_2d_neon.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/arm/conv_2d_neon_1x15.cc b/mace/ops/arm/conv_2d_neon_1x15.cc
index 33b9abbfebc2c921423b15288012487038d2b370..b8837490da72d003b4458853045adea5cd51bac6 100644
--- a/mace/ops/arm/conv_2d_neon_1x15.cc
+++ b/mace/ops/arm/conv_2d_neon_1x15.cc
@@ -18,7 +18,7 @@
 
 #include "mace/ops/arm/conv_2d_neon.h"
 #include "mace/utils/logging.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/arm/conv_2d_neon_3x3.cc b/mace/ops/arm/conv_2d_neon_3x3.cc
index ecae6810696d07d82d688a183720c7acb3243f8d..3555b4a57078433c47c8d8ba34b60a649367b617 100644
--- a/mace/ops/arm/conv_2d_neon_3x3.cc
+++ b/mace/ops/arm/conv_2d_neon_3x3.cc
@@ -16,7 +16,7 @@
 #include <arm_neon.h>
 #endif
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/conv_2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/deconv_2d_neon_2x2.cc b/mace/ops/arm/deconv_2d_neon_2x2.cc
index 74ddbecc48c367c07692e43b6260ece23aee6abb..a1bd1883e380d57bf17da2ac07af25963921dfdf 100644
--- a/mace/ops/arm/deconv_2d_neon_2x2.cc
+++ b/mace/ops/arm/deconv_2d_neon_2x2.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/deconv_2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/deconv_2d_neon_3x3.cc b/mace/ops/arm/deconv_2d_neon_3x3.cc
index 356680949af572838a070c47f91a69427751d596..2859b7c04bcc68e4c6454a63aa7969132cc0fb7f 100644
--- a/mace/ops/arm/deconv_2d_neon_3x3.cc
+++ b/mace/ops/arm/deconv_2d_neon_3x3.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/deconv_2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/deconv_2d_neon_4x4.cc b/mace/ops/arm/deconv_2d_neon_4x4.cc
index a023154aec04c94ff4dcc77767999522a87a0368..690bea4ed99d6823d162db2cc068e26b220ea339 100644
--- a/mace/ops/arm/deconv_2d_neon_4x4.cc
+++ b/mace/ops/arm/deconv_2d_neon_4x4.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/deconv_2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/depthwise_conv2d_neon_3x3.cc b/mace/ops/arm/depthwise_conv2d_neon_3x3.cc
index 652d0231bdc60c6f3b53c65b3a94131e7de47d15..9d6ae41e16e2c0a8a525cfbd47a9662583f84e8d 100644
--- a/mace/ops/arm/depthwise_conv2d_neon_3x3.cc
+++ b/mace/ops/arm/depthwise_conv2d_neon_3x3.cc
@@ -16,7 +16,7 @@
 #include <arm_neon.h>
 #endif
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/depthwise_conv2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/depthwise_deconv2d_neon_3x3.cc b/mace/ops/arm/depthwise_deconv2d_neon_3x3.cc
index 404c903d30d0ca30695c94d889f9346764967c64..a666961b39186151ceb2af2c8a729e637f00f04d 100644
--- a/mace/ops/arm/depthwise_deconv2d_neon_3x3.cc
+++ b/mace/ops/arm/depthwise_deconv2d_neon_3x3.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/depthwise_deconv2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/depthwise_deconv2d_neon_4x4.cc b/mace/ops/arm/depthwise_deconv2d_neon_4x4.cc
index 1b59264e600c064f76dddfbcf3b6b4ec83d535a2..a7c10b8601bb6783096d466f003e2ba4d4550184 100644
--- a/mace/ops/arm/depthwise_deconv2d_neon_4x4.cc
+++ b/mace/ops/arm/depthwise_deconv2d_neon_4x4.cc
@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/ops/arm/deconv_2d_neon.h"
 
 namespace mace {
diff --git a/mace/ops/arm/fp32/conv_2d_3x3_winograd.cc b/mace/ops/arm/fp32/conv_2d_3x3_winograd.cc
index 12655eacd9b170355a2f560e0c0f0979b13863f4..84f12125649fce6c701356d9a9395383efd463b2 100644
--- a/mace/ops/arm/fp32/conv_2d_3x3_winograd.cc
+++ b/mace/ops/arm/fp32/conv_2d_3x3_winograd.cc
@@ -16,6 +16,8 @@
 
 #include "mace/ops/arm/fp32/conv_2d_3x3_winograd.h"
 #include "mace/ops/common/conv_pool_2d_util.h"
+#include "mace/utils/memory.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/arm/fp32/gemm.h b/mace/ops/arm/fp32/gemm.h
index f4cfc42bb199161a877ab0329670004ef94a6b97..36eb0378b9853c9a6145bfc5a2d1b0ada9afbc44 100644
--- a/mace/ops/arm/fp32/gemm.h
+++ b/mace/ops/arm/fp32/gemm.h
@@ -19,6 +19,7 @@
 #include "mace/core/tensor.h"
 #include "mace/core/op_context.h"
 #include "mace/ops/common/matrix.h"
+#include "mace/utils/math.h"
 
 // This implements matrix-matrix multiplication.
 // In the case of matrix-vector multiplication, use gemv.h/gemv.cc instead
diff --git a/mace/ops/arm/fp32/gemv.cc b/mace/ops/arm/fp32/gemv.cc
index 89474fbb16965f262dba50b7c26542cabdf61511..cd0f607fd63f16bb5c99ea0a369dc8423a6bf358 100644
--- a/mace/ops/arm/fp32/gemv.cc
+++ b/mace/ops/arm/fp32/gemv.cc
@@ -18,6 +18,8 @@
 #include <arm_neon.h>
 #include <algorithm>
 
+#include "mace/utils/math.h"
+
 #if !defined(__aarch64__)
 float vaddvq_f32(float32x4_t v) {
   float32x2_t _sum = vadd_f32(vget_low_f32(v), vget_high_f32(v));
diff --git a/mace/ops/arm/q8/gemv.cc b/mace/ops/arm/q8/gemv.cc
index d52ed48d65a2b8683dd68c88ba88ee84d82c660d..ce102e7e3171ff3344b4535576c9187866305fcd 100644
--- a/mace/ops/arm/q8/gemv.cc
+++ b/mace/ops/arm/q8/gemv.cc
@@ -18,7 +18,7 @@
 #include <arm_neon.h>
 #include <algorithm>
 
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #include "mace/utils/quantize.h"
 
 #if !defined(__aarch64__)
diff --git a/mace/ops/batch_norm_benchmark.cc b/mace/ops/batch_norm_benchmark.cc
index 11bf4f6e74dbfd7141963add244c50f8b9b1ff35..74f7a013c14af8294aaabcddf5a7a29d8662edf1 100644
--- a/mace/ops/batch_norm_benchmark.cc
+++ b/mace/ops/batch_norm_benchmark.cc
@@ -12,7 +12,6 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#include "mace/core/runtime/opencl/opencl_runtime.h"
 #include "mace/core/testing/test_benchmark.h"
 #include "mace/ops/ops_test_util.h"
 
diff --git a/mace/ops/conv_2d.cc b/mace/ops/conv_2d.cc
index 4d54effae7899291a69e97ff25dc2b5f0f3b6b8c..65a723ad649be63332513ad69e989edc9b675368 100644
--- a/mace/ops/conv_2d.cc
+++ b/mace/ops/conv_2d.cc
@@ -31,7 +31,7 @@
 #include "mace/ops/conv_pool_2d_base.h"
 #include "mace/ops/common/conv_pool_2d_util.h"
 #include "mace/utils/memory.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 #ifdef MACE_ENABLE_NEON
 #include "mace/ops/arm/fp32/conv_2d.h"
diff --git a/mace/ops/deconv_2d.cc b/mace/ops/deconv_2d.cc
index 3585659f5229e3f315e0a415d78dade8915beea2..6e9a0fa8db36209887f86d0fdc75d5c5d1a5c2bc 100644
--- a/mace/ops/deconv_2d.cc
+++ b/mace/ops/deconv_2d.cc
@@ -29,7 +29,7 @@
 #include "mace/ops/activation.h"
 #include "mace/ops/arm/deconv_2d_neon.h"
 #include "mace/utils/memory.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #ifdef MACE_ENABLE_OPENCL
 #include "mace/ops/opencl/buffer_transformer.h"
 #include "mace/ops/opencl/image/deconv_2d.h"
diff --git a/mace/ops/depthwise_deconv2d.cc b/mace/ops/depthwise_deconv2d.cc
index a2d188a96a78bcc51ba4d48312d8ab3b155f3721..3d203cfa5678c1ca407b6db2d441890bc00785a5 100644
--- a/mace/ops/depthwise_deconv2d.cc
+++ b/mace/ops/depthwise_deconv2d.cc
@@ -26,7 +26,7 @@
 #include "mace/core/future.h"
 #include "mace/core/tensor.h"
 #include "mace/ops/arm/depthwise_deconv2d_neon.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #include "mace/public/mace.h"
 #include "mace/utils/memory.h"
 #ifdef MACE_ENABLE_OPENCL
diff --git a/mace/ops/matmul.cc b/mace/ops/matmul.cc
index 3c971b6f9921d9ab737c719685a3d85967a8da2f..3b0913de574607660b807ea133f3e797a30aca71 100644
--- a/mace/ops/matmul.cc
+++ b/mace/ops/matmul.cc
@@ -21,7 +21,7 @@
 
 #include "mace/core/operator.h"
 #include "mace/core/tensor.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 #ifdef MACE_ENABLE_NEON
 #include "mace/ops/arm/fp32/gemm.h"
diff --git a/mace/ops/opencl/activation.h b/mace/ops/opencl/activation.h
index 6eecb6416659f899e4926332a02695597782ee62..6e9b92242b499906fb3304fdcedfc1e739e9abb4 100644
--- a/mace/ops/opencl/activation.h
+++ b/mace/ops/opencl/activation.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_ACTIVATION_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/addn.h b/mace/ops/opencl/addn.h
index b78a7099646f77f40e5f2c058d90dcd414cb0dec..ba161ba641ed6d1c041e2e41aa547f1c45071e48 100644
--- a/mace/ops/opencl/addn.h
+++ b/mace/ops/opencl/addn.h
@@ -18,7 +18,7 @@
 #include <vector>
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/batch_norm.h b/mace/ops/opencl/batch_norm.h
index 6f91f95d67d4efe23ae9b8eb57142ea7ba1f3acd..bf49c994e127910632dfd2b2ce9d76a4855a29dc 100644
--- a/mace/ops/opencl/batch_norm.h
+++ b/mace/ops/opencl/batch_norm.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_BATCH_NORM_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/batch_to_space.h b/mace/ops/opencl/batch_to_space.h
index 4cf8db94399d13ed77391d80f8d7447b8edff59a..9bb62f7052d64ba437d44f5d0ed6403c475c3dde 100644
--- a/mace/ops/opencl/batch_to_space.h
+++ b/mace/ops/opencl/batch_to_space.h
@@ -19,7 +19,7 @@
 
 #include "mace/core/types.h"
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/bias_add.h b/mace/ops/opencl/bias_add.h
index d0b4469dd0154ae7234f984771ffa70509abeb32..80a86423c50922bec581b445206445cf2df83d41 100644
--- a/mace/ops/opencl/bias_add.h
+++ b/mace/ops/opencl/bias_add.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_BIAS_ADD_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/buffer_transform_kernel.h b/mace/ops/opencl/buffer_transform_kernel.h
index 4269b67d22ca157f28fcde4a0f607f9ae6e9a5df..47f1cbaf10f4cf70c0a1d9014ba0ad77261414fe 100644
--- a/mace/ops/opencl/buffer_transform_kernel.h
+++ b/mace/ops/opencl/buffer_transform_kernel.h
@@ -17,7 +17,7 @@
 
 #include "mace/core/runtime/opencl/opencl_util.h"
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 class OpContext;
diff --git a/mace/ops/opencl/channel_shuffle.h b/mace/ops/opencl/channel_shuffle.h
index 86634d75bc0bb0e13254ec0a9c82714f7b746fda..df4a4b0f8e7fd92a0e4663643aeb1ef66de04e79 100644
--- a/mace/ops/opencl/channel_shuffle.h
+++ b/mace/ops/opencl/channel_shuffle.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_CHANNEL_SHUFFLE_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/concat.h b/mace/ops/opencl/concat.h
index d657ffbe9bdd2f69301b9f519491433531822f8d..abeec7c62e25299ac4de95e0b0dadc61bdb35900 100644
--- a/mace/ops/opencl/concat.h
+++ b/mace/ops/opencl/concat.h
@@ -18,7 +18,7 @@
 #include <vector>
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/crop.h b/mace/ops/opencl/crop.h
index 88aceea6f93845ece318b8b26b45e25eaf24dbfc..b12c5ee00fed43c0f954921bac11a26fa21e0f7e 100644
--- a/mace/ops/opencl/crop.h
+++ b/mace/ops/opencl/crop.h
@@ -18,7 +18,7 @@
 #include <vector>
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/depth_to_space.h b/mace/ops/opencl/depth_to_space.h
index 17c03d453593ccb7ca1c1ae58890f80b01a5c706..9d2d4fcba65fe01545c2588cdb9d667f53408af7 100644
--- a/mace/ops/opencl/depth_to_space.h
+++ b/mace/ops/opencl/depth_to_space.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_DEPTH_TO_SPACE_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 namespace mace {
 
 class OpContext;
diff --git a/mace/ops/opencl/eltwise.h b/mace/ops/opencl/eltwise.h
index dec2b150d79a372a05895482a7db1819766b20e5..52156f06e908a394ae910abbeefb6da23e6cb236 100644
--- a/mace/ops/opencl/eltwise.h
+++ b/mace/ops/opencl/eltwise.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_ELTWISE_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/fully_connected.h b/mace/ops/opencl/fully_connected.h
index 8e421ad2f20510a76dcc0c5c841745d1832ac688..416aed6c8692ceaf45da1d1eb36f82b3753c8729 100644
--- a/mace/ops/opencl/fully_connected.h
+++ b/mace/ops/opencl/fully_connected.h
@@ -18,7 +18,7 @@
 #include "mace/ops/activation.h"
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/helper.cc b/mace/ops/opencl/helper.cc
index a801e91048efaca60e08f52e36367aa09cbee317..912a8d8d87e549290cf5d174187d288c2462fcb1 100644
--- a/mace/ops/opencl/helper.cc
+++ b/mace/ops/opencl/helper.cc
@@ -19,7 +19,7 @@
 #include <vector>
 
 #include "mace/utils/tuner.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/opencl/helper.h b/mace/ops/opencl/helper.h
index cf3beeac9d304b6530c29c395979527b33cc326c..a4a49b4e15a021f1fa55fbd39c514777f03005bd 100644
--- a/mace/ops/opencl/helper.h
+++ b/mace/ops/opencl/helper.h
@@ -21,13 +21,13 @@
 #include <vector>
 
 #include "mace/core/future.h"
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/core/runtime/opencl/cl2_header.h"
 #include "mace/core/runtime/opencl/opencl_runtime.h"
 #include "mace/core/runtime/opencl/opencl_util.h"
 #include "mace/core/types.h"
 #include "mace/utils/memory.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/opencl/image/conv_2d_3x3.cc b/mace/ops/opencl/image/conv_2d_3x3.cc
index db63300eb7607dead1cc9661533e0e7d463e5e4b..125a973ae7de4409b31fa2a716c35409d5955d0e 100644
--- a/mace/ops/opencl/image/conv_2d_3x3.cc
+++ b/mace/ops/opencl/image/conv_2d_3x3.cc
@@ -16,7 +16,7 @@
 #include "mace/core/runtime/opencl/opencl_runtime.h"
 #include "mace/ops/common/activation_type.h"
 #include "mace/ops/opencl/helper.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/opencl/image/conv_2d_general.cc b/mace/ops/opencl/image/conv_2d_general.cc
index 08568a5d9e39d671a2e3d84de8fc1fa22c588f95..7f0250cbc4ebc73cfa52c6041c9da8c95b7e3892 100644
--- a/mace/ops/opencl/image/conv_2d_general.cc
+++ b/mace/ops/opencl/image/conv_2d_general.cc
@@ -16,7 +16,7 @@
 #include "mace/core/runtime/opencl/opencl_runtime.h"
 #include "mace/ops/opencl/helper.h"
 #include "mace/ops/common/activation_type.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/opencl/image/winograd_conv2d.cc b/mace/ops/opencl/image/winograd_conv2d.cc
index 0bda447005a413e2503a096cd18defe4a181ce0e..27a0bc30533f4538a537dc6c3084178ee1d5d3cd 100644
--- a/mace/ops/opencl/image/winograd_conv2d.cc
+++ b/mace/ops/opencl/image/winograd_conv2d.cc
@@ -18,7 +18,7 @@
 #include "mace/ops/common/conv_pool_2d_util.h"
 #include "mace/ops/opencl/helper.h"
 #include "mace/utils/memory.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/opencl/lstm_cell.h b/mace/ops/opencl/lstm_cell.h
index 07ea2e65551092d5c8dcfe561a2dcaecc8c9261a..4dee034c12fa858fea262e2977d5383b5863e9b3 100644
--- a/mace/ops/opencl/lstm_cell.h
+++ b/mace/ops/opencl/lstm_cell.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_LSTM_CELL_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/matmul.h b/mace/ops/opencl/matmul.h
index c51c83c146fdc7834de05522f8ab6939f4974673..05879f8ae2ed8623652316d13e0526e48a584b3b 100644
--- a/mace/ops/opencl/matmul.h
+++ b/mace/ops/opencl/matmul.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_MATMUL_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/pad.h b/mace/ops/opencl/pad.h
index cfc7edb3a1351e1b9bf8d1a152e4d906c6f09d47..640137691964b9e57cca9e69ee0c73a8d85420f0 100644
--- a/mace/ops/opencl/pad.h
+++ b/mace/ops/opencl/pad.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_PAD_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 namespace mace {
 
 class OpContext;
diff --git a/mace/ops/opencl/reduce.h b/mace/ops/opencl/reduce.h
index 4f6aa2187561a22ac0e6758b45738a73a6bf9fa7..f653f8b02805dfb387d38b617eed2256e70255d9 100644
--- a/mace/ops/opencl/reduce.h
+++ b/mace/ops/opencl/reduce.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_REDUCE_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/resize_bicubic.h b/mace/ops/opencl/resize_bicubic.h
index 4fde45453b6335e2ca1a1eab8c57f909b253e97b..b7fd71a0dbcddc85322fae1b2a8973a1b63af1b5 100644
--- a/mace/ops/opencl/resize_bicubic.h
+++ b/mace/ops/opencl/resize_bicubic.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_RESIZE_BICUBIC_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #include "mace/core/types.h"
 
 namespace mace {
diff --git a/mace/ops/opencl/resize_bilinear.h b/mace/ops/opencl/resize_bilinear.h
index 18dd312845b0bcba5ed91a1f9ad5aa0311e2279a..66035d8511136952eeefe92efce0a3fd614aad5e 100644
--- a/mace/ops/opencl/resize_bilinear.h
+++ b/mace/ops/opencl/resize_bilinear.h
@@ -17,7 +17,7 @@
 
 #include "mace/core/types.h"
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/resize_nearest_neighbor.h b/mace/ops/opencl/resize_nearest_neighbor.h
index fda220aee9704228d435a304001a5f679f2d28e3..b0178827ac6190d413b179b4a98c367d1e5f9c37 100644
--- a/mace/ops/opencl/resize_nearest_neighbor.h
+++ b/mace/ops/opencl/resize_nearest_neighbor.h
@@ -17,7 +17,7 @@
 
 #include "mace/core/types.h"
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/softmax.h b/mace/ops/opencl/softmax.h
index caca5dc693a6d2e8735edc91a0f5c9f0feab65c4..a4a439ec1501db36a417c2d533d14cf1bea103e5 100644
--- a/mace/ops/opencl/softmax.h
+++ b/mace/ops/opencl/softmax.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_SOFTMAX_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/space_to_batch.h b/mace/ops/opencl/space_to_batch.h
index 350bf120975c6e3747e8cb5c848d9eb88f646d71..9f73ff5acdfaaa7956219bff51c42c4beb9c40b4 100644
--- a/mace/ops/opencl/space_to_batch.h
+++ b/mace/ops/opencl/space_to_batch.h
@@ -19,7 +19,7 @@
 
 #include "mace/core/types.h"
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/space_to_depth.h b/mace/ops/opencl/space_to_depth.h
index 69e40c82a0e3d7d06cd181d52bb71f7f1b7bd8e0..454cb686e7d1589c3c1329cc97d7a60b3c9ed663 100644
--- a/mace/ops/opencl/space_to_depth.h
+++ b/mace/ops/opencl/space_to_depth.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_SPACE_TO_DEPTH_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/split.h b/mace/ops/opencl/split.h
index 61f75d85c6f2c3032eacbeb908bb79edf61c26ea..8c7ac5636b77a1d07449d6f8ce09c77a6934b537 100644
--- a/mace/ops/opencl/split.h
+++ b/mace/ops/opencl/split.h
@@ -18,7 +18,7 @@
 #include <vector>
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 
diff --git a/mace/ops/opencl/sqrdiff_mean.h b/mace/ops/opencl/sqrdiff_mean.h
index 822b992f0009726210126bcb19d06f480dcbf7ca..781a08c56568bf6f27230abd109d53ab24faa7e3 100644
--- a/mace/ops/opencl/sqrdiff_mean.h
+++ b/mace/ops/opencl/sqrdiff_mean.h
@@ -16,7 +16,7 @@
 #define MACE_OPS_OPENCL_SQRDIFF_MEAN_H_
 
 #include "mace/public/mace.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 namespace mace {
 
 class OpContext;
diff --git a/mace/ops/ops_test_util.h b/mace/ops/ops_test_util.h
index f60fff1d39cb86e51b8c63dae1f94fc4089efb41..19fe05d32e9f850d8a77cdadf1008c78b74b9ef7 100644
--- a/mace/ops/ops_test_util.h
+++ b/mace/ops/ops_test_util.h
@@ -35,7 +35,7 @@
 #include "mace/ops/ops_registry.h"
 #include "mace/public/mace.h"
 #include "mace/utils/memory.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/math.h"
 #include "mace/utils/quantize.h"
 #include "mace/ops/testing/test_utils.h"
 
diff --git a/mace/ops/pad.cc b/mace/ops/pad.cc
index 7c20edd9fdd07e5fef11b5719f170d8c35946f51..aaa6b230f4b5237dc88d16e369dcf289a8fe9df6 100644
--- a/mace/ops/pad.cc
+++ b/mace/ops/pad.cc
@@ -21,6 +21,7 @@
 #include "mace/ops/opencl/image/pad.h"
 #endif  // MACE_ENABLE_OPENCL
 #include "mace/utils/memory.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/reduce.cc b/mace/ops/reduce.cc
index 860660be825fbdb2cf980e8b136cfde0909bd155..068212f204d85a3129d1f7ad9e9cbe0cfca06491 100644
--- a/mace/ops/reduce.cc
+++ b/mace/ops/reduce.cc
@@ -85,7 +85,7 @@ class ReduceOp<DeviceType::CPU, T> : public ReduceOpBase {
  private:
   void Simplify(const Tensor *input) {
     std::vector<bool> bitmap(static_cast<uint32_t>(input->dim_size()), false);
-    if (axis_.size() == 0) {
+    if (axis_.empty()) {
       for (int i = 0; i < input->dim_size(); ++i) {
         bitmap[i] = true;
       }
diff --git a/mace/ops/reshape.cc b/mace/ops/reshape.cc
index e578e69aec0f314e854c70fabd411c61bc3f81bc..98ea215e7678b32170bf98d415b0c88ec23a60e6 100644
--- a/mace/ops/reshape.cc
+++ b/mace/ops/reshape.cc
@@ -15,6 +15,7 @@
 #include <vector>
 
 #include "mace/core/operator.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/softmax.cc b/mace/ops/softmax.cc
index 693058a372198f7eb0848ef84e9aab78e4e2645c..cbab37adf5ebe9e0a3195483cecc287be5931bd0 100644
--- a/mace/ops/softmax.cc
+++ b/mace/ops/softmax.cc
@@ -134,10 +134,10 @@ class SoftmaxOp<DeviceType::CPU, float> : public Operation {
   }
 };
 
+#ifdef MACE_ENABLE_QUANTIZE
 static const int kInputDeltaIntBits = 6;
 static const int kSumExpIntBits = 12;
 
-#ifdef MACE_ENABLE_QUANTIZE
 template <>
 class SoftmaxOp<DeviceType::CPU, uint8_t> : public Operation {
  public:
diff --git a/mace/ops/splice.cc b/mace/ops/splice.cc
index 9093b8aada66d2ccdf69ca5ae27bfb19322bced6..bf1dfe36b41e8c79675f3d75b0578fa2ce76816e 100644
--- a/mace/ops/splice.cc
+++ b/mace/ops/splice.cc
@@ -32,6 +32,7 @@
 #include <memory>
 
 #include "mace/core/operator.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/testing/test_utils.h b/mace/ops/testing/test_utils.h
index 59e71448f6421d51a8d67f77d17e49420fe7a915..6a0a045b6326a67689f9755bc911a2f54fbc798a 100644
--- a/mace/ops/testing/test_utils.h
+++ b/mace/ops/testing/test_utils.h
@@ -27,6 +27,7 @@
 #include <vector>
 
 #include "mace/core/tensor.h"
+#include "gtest/gtest.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/ops/time_offset.cc b/mace/ops/time_offset.cc
index 2fff53c1124e2795551fed7d55b588c101489096..d9343fc327438a965fe4b3e98a583783a6d4993a 100644
--- a/mace/ops/time_offset.cc
+++ b/mace/ops/time_offset.cc
@@ -19,6 +19,7 @@
 #include <memory>
 
 #include "mace/core/operator.h"
+#include "mace/utils/math.h"
 
 namespace mace {
 namespace ops {
diff --git a/mace/port/BUILD.bazel b/mace/port/BUILD.bazel
new file mode 100644
index 0000000000000000000000000000000000000000..30db894567f71c603ab00ca4a7520d35289636f7
--- /dev/null
+++ b/mace/port/BUILD.bazel
@@ -0,0 +1,52 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+cc_library(
+    name = "port",
+    deps = [
+        "//mace/port/android:port_android",
+        "//mace/port/darwin:port_darwin",
+        "//mace/port/linux:port_linux",
+    ],
+)
+
+cc_library(
+    name = "port_api",
+    hdrs = [
+        "env.h",
+        "file_system.h",
+        "logger.h",
+    ],
+    deps = [
+        "//mace/public",
+    ],
+)
+
+cc_library(
+    name = "port_base",
+    srcs = [
+        "env.cc",
+        "logger.cc",
+    ],
+    deps = [
+        ":port_api",
+        "//mace/utils",
+    ],
+)
+
+cc_test(
+    name = "port_test",
+    testonly = 1,
+    srcs = glob([
+        "*_test.cc",
+    ]),
+    linkstatic = 0,
+    deps = [
+        ":port",
+        "@gtest//:gtest",
+        "@gtest//:gtest_main",
+    ],
+)
diff --git a/mace/port/README.md b/mace/port/README.md
new file mode 100644
index 0000000000000000000000000000000000000000..9ecfff01571db8bcfa4733e1f4e4979763b81d8d
--- /dev/null
+++ b/mace/port/README.md
@@ -0,0 +1,14 @@
+# port
+
+This module contains the interface and implementations for different platforms.
+All platform specific code should go here. It's not allowed to use non standard
+headers in other modules.
+
+This module splits into `port_api` and `port`. `port_api` is the interface, and
+it should not depends on any other modules including `utils`.
+
+If the code base goes large in the future, it should be split into core and
+test to keep the footprint for production libs as small as possible.
+
+Currently Linux, Darwin (MacOS, iOS etc.) are treated as POSIX. They will be
+handled differently if needed.
diff --git a/mace/port/android/BUILD.bazel b/mace/port/android/BUILD.bazel
new file mode 100644
index 0000000000000000000000000000000000000000..fd5aacc51f3653a32a6fa4b5f5752772d6dd20bc
--- /dev/null
+++ b/mace/port/android/BUILD.bazel
@@ -0,0 +1,22 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+load("//mace:mace.bzl", "if_android")
+
+cc_library(
+    name = "port_android",
+    srcs = if_android(glob([
+        "*.cc",
+    ])),
+    hdrs = if_android(glob([
+        "*.h",
+    ])),
+    deps = [
+        "//mace/port:port_base",
+        "//mace/port/posix:port_posix",
+    ],
+    alwayslink = 1,
+)
diff --git a/mace/port/android/env.cc b/mace/port/android/env.cc
new file mode 100644
index 0000000000000000000000000000000000000000..774511fdfbb4ac26ea514f4f799d619c8188cf85
--- /dev/null
+++ b/mace/port/android/env.cc
@@ -0,0 +1,204 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/android/env.h"
+
+#include <errno.h>
+#include <unwind.h>
+#include <dlfcn.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+
+#ifdef __hexagon__
+#include <HAP_perf.h>
+#else
+#include <sys/time.h>
+#endif
+
+#include <cstdint>
+#include <memory>
+#include <fstream>
+#include <string>
+#include <vector>
+#include <utility>
+
+#include "mace/port/android/malloc_logger.h"
+#include "mace/port/posix/time.h"
+#include "mace/utils/macros.h"
+#include "mace/utils/memory.h"
+#include "mace/utils/logging.h"
+
+namespace mace {
+namespace port {
+
+int64_t AndroidEnv::NowMicros() {
+#ifdef __hexagon__
+  return HAP_perf_get_time_us();
+#else
+  return mace::port::posix::NowMicros();
+#endif
+}
+
+FileSystem *AndroidEnv::GetFileSystem() {
+  return &posix_file_system_;
+}
+
+LogWriter *AndroidEnv::GetLogWriter() {
+  return &log_writer_;
+}
+
+namespace {
+
+int GetCpuCount() {
+  int cpu_count = 0;
+  std::string cpu_sys_conf = "/proc/cpuinfo";
+  std::ifstream f(cpu_sys_conf);
+  if (!f.is_open()) {
+    LOG(ERROR) << "failed to open " << cpu_sys_conf;
+    return -1;
+  }
+  std::string line;
+  const std::string processor_key = "processor";
+  while (std::getline(f, line)) {
+    if (line.size() >= processor_key.size()
+        && line.compare(0, processor_key.size(), processor_key) == 0) {
+      ++cpu_count;
+    }
+  }
+  if (f.bad()) {
+    LOG(ERROR) << "failed to read " << cpu_sys_conf;
+  }
+  if (!f.eof()) {
+    LOG(ERROR) << "failed to read end of " << cpu_sys_conf;
+  }
+  f.close();
+  VLOG(1) << "CPU cores: " << cpu_count;
+  return cpu_count;
+}
+
+struct BacktraceState {
+  void** current;
+  void** end;
+};
+
+_Unwind_Reason_Code UnwindCallback(struct _Unwind_Context* context, void* arg) {
+  BacktraceState* state = static_cast<BacktraceState*>(arg);
+  uintptr_t pc = _Unwind_GetIP(context);
+  if (pc) {
+    if (state->current == state->end) {
+      return _URC_END_OF_STACK;
+    } else {
+      *state->current++ = reinterpret_cast<void*>(pc);
+    }
+  }
+  return _URC_NO_REASON;
+}
+
+size_t BackTrace(void** buffer, size_t max) {
+  BacktraceState state = {buffer, buffer + max};
+  _Unwind_Backtrace(UnwindCallback, &state);
+
+  return state.current - buffer;
+}
+
+}  // namespace
+
+MaceStatus AndroidEnv::GetCpuMaxFreq(std::vector<float> *max_freqs) {
+  MACE_CHECK_NOTNULL(max_freqs);
+  int cpu_count = GetCpuCount();
+  if (cpu_count < 0) {
+    return MaceStatus::MACE_RUNTIME_ERROR;
+  }
+  for (int cpu_id = 0; cpu_id < cpu_count; ++cpu_id) {
+    std::string cpuinfo_max_freq_sys_conf = MakeString(
+        "/sys/devices/system/cpu/cpu",
+        cpu_id,
+        "/cpufreq/cpuinfo_max_freq");
+    std::ifstream f(cpuinfo_max_freq_sys_conf);
+    if (!f.is_open()) {
+      LOG(ERROR) << "failed to open " << cpuinfo_max_freq_sys_conf;
+      return MaceStatus::MACE_RUNTIME_ERROR;
+    }
+    std::string line;
+    if (std::getline(f, line)) {
+      float freq = strtof(line.c_str(), nullptr);
+      max_freqs->push_back(freq);
+    }
+    if (f.bad()) {
+      LOG(ERROR) << "failed to read " << cpuinfo_max_freq_sys_conf;
+    }
+    f.close();
+  }
+
+  if (VLOG_IS_ON(1)) VLOG(1) << "CPU freq: " << MakeString(*max_freqs);
+
+  return MaceStatus::MACE_SUCCESS;
+}
+
+MaceStatus AndroidEnv::SchedSetAffinity(const std::vector<size_t> &cpu_ids) {
+  // compute mask
+  cpu_set_t mask;
+  CPU_ZERO(&mask);
+  for (auto cpu_id : cpu_ids) {
+    CPU_SET(cpu_id, &mask);
+  }
+  pid_t pid = gettid();
+  int err = sched_setaffinity(pid, sizeof(mask), &mask);
+  if (err) {
+    LOG(WARNING) << "SchedSetAffinity failed: " << strerror(errno);
+    return MaceStatus(MaceStatus::MACE_INVALID_ARGS,
+                      "SchedSetAffinity failed: " +
+                      std::string(strerror(errno)));
+  }
+
+  return MaceStatus::MACE_SUCCESS;
+}
+
+std::vector<std::string> AndroidEnv::GetBackTraceUnsafe(int max_steps) {
+  std::vector<void *> buffer(max_steps, 0);
+  int steps = BackTrace(buffer.data(), max_steps);
+
+  std::vector<std::string> bt;
+  for (int i = 0; i < steps; ++i) {
+    std::ostringstream os;
+
+    const void* addr = buffer[i];
+    const char* symbol = "";
+    Dl_info info;
+    if (dladdr(addr, &info) && info.dli_sname) {
+      symbol = info.dli_sname;
+    }
+
+    os << "pc " << addr << " " << symbol;
+
+    bt.push_back(os.str());
+  }
+
+  return bt;
+}
+
+std::unique_ptr<MallocLogger> AndroidEnv::NewMallocLogger(
+    std::ostringstream *oss,
+    const std::string &name) {
+  return make_unique<AndroidMallocLogger>(oss, name);
+}
+
+Env *Env::Default() {
+  static AndroidEnv android_env;
+  return &android_env;
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/android/env.h b/mace/port/android/env.h
new file mode 100644
index 0000000000000000000000000000000000000000..04c3b35b98b66c17f6c191a749abe74dc82825ab
--- /dev/null
+++ b/mace/port/android/env.h
@@ -0,0 +1,49 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_ANDROID_ENV_H_
+#define MACE_PORT_ANDROID_ENV_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "mace/port/android/logger.h"
+#include "mace/port/posix/file_system.h"
+#include "mace/port/env.h"
+
+namespace mace {
+namespace port {
+
+class AndroidEnv : public Env {
+ public:
+  int64_t NowMicros() override;
+  MaceStatus GetCpuMaxFreq(std::vector<float> *max_freqs) override;
+  MaceStatus SchedSetAffinity(const std::vector<size_t> &cpu_ids) override;
+  FileSystem *GetFileSystem() override;
+  LogWriter *GetLogWriter() override;
+  std::vector<std::string> GetBackTraceUnsafe(int max_steps) override;
+  std::unique_ptr<MallocLogger> NewMallocLogger(
+      std::ostringstream *oss,
+      const std::string &name) override;
+
+ private:
+  PosixFileSystem posix_file_system_;
+  AndroidLogWriter log_writer_;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_ANDROID_ENV_H_
diff --git a/mace/port/android/logger.cc b/mace/port/android/logger.cc
new file mode 100644
index 0000000000000000000000000000000000000000..c0fd5f6bceaa36f41dc964c02396af20a718318a
--- /dev/null
+++ b/mace/port/android/logger.cc
@@ -0,0 +1,58 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/android/logger.h"
+
+#include <android/log.h>
+
+#include <iostream>
+
+namespace mace {
+namespace port {
+
+void AndroidLogWriter::WriteLogMessage(const char *fname,
+                                       const int line,
+                                       const LogLevel severity,
+                                       const char *message) {
+  int android_log_level;
+  switch (severity) {
+    case INFO:
+      android_log_level = ANDROID_LOG_INFO;
+      break;
+    case WARNING:
+      android_log_level = ANDROID_LOG_WARN;
+      break;
+    case ERROR:
+      android_log_level = ANDROID_LOG_ERROR;
+      break;
+    case FATAL:
+      android_log_level = ANDROID_LOG_FATAL;
+      break;
+    default:
+      android_log_level = ANDROID_LOG_ERROR;
+      break;
+  }
+
+  std::stringstream ss;
+  const char *const partial_name = strrchr(fname, '/');
+  ss << (partial_name != nullptr ? partial_name + 1 : fname) << ":" << line
+     << " " << message;
+  __android_log_write(android_log_level, "CRT", ss.str().c_str());
+
+  // Also log to stderr (for standalone Android apps) and abort.
+  LogWriter::WriteLogMessage(fname, line, severity, message);
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/android/logger.h b/mace/port/android/logger.h
new file mode 100644
index 0000000000000000000000000000000000000000..fccfb83515c360bf61245dfcabfe73776b7702a7
--- /dev/null
+++ b/mace/port/android/logger.h
@@ -0,0 +1,34 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_ANDROID_LOGGER_H_
+#define MACE_PORT_ANDROID_LOGGER_H_
+
+#include "mace/port/logger.h"
+
+namespace mace {
+namespace port {
+
+class AndroidLogWriter : public LogWriter {
+ protected:
+  void WriteLogMessage(const char *fname,
+                       const int line,
+                       const LogLevel severity,
+                       const char *message) override;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_ANDROID_LOGGER_H_
diff --git a/mace/port/android/malloc_logger.cc b/mace/port/android/malloc_logger.cc
new file mode 100644
index 0000000000000000000000000000000000000000..afaef724309d103ed15ac584b8f41c49d92c363d
--- /dev/null
+++ b/mace/port/android/malloc_logger.cc
@@ -0,0 +1,100 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/android/malloc_logger.h"
+
+#include <malloc.h>
+
+#include <string>
+#include <utility>
+
+namespace mace {
+namespace port {
+
+namespace {
+struct mallinfo LogMallinfoChange(std::ostringstream *oss,
+                                  const std::string &name,
+                                  const struct mallinfo curr,
+                                  const struct mallinfo prev) {
+  if (prev.arena != curr.arena) {
+    (*oss) << "[" << name << "] "
+           << "Non-mmapped space allocated (bytes): " << curr.arena
+           << ", diff: " << ((int64_t)curr.arena - (int64_t)prev.arena);
+  }
+  if (prev.ordblks != curr.ordblks) {
+    (*oss) << "[" << name << "] "
+           << "Number of free chunks: " << curr.ordblks << ", diff: "
+           << ((int64_t)curr.ordblks - (int64_t)prev.ordblks);
+  }
+  if (prev.smblks != curr.smblks) {
+    (*oss) << "[" << name << "] "
+           << "Number of free fastbin blocks: " << curr.smblks
+           << ", diff: " << ((int64_t)curr.smblks - (int64_t)prev.smblks);
+  }
+  if (prev.hblks != curr.hblks) {
+    (*oss) << "[" << name << "] "
+           << "Number of mmapped regions: " << curr.hblks
+           << ", diff: " << ((int64_t)curr.hblks - (int64_t)prev.hblks);
+  }
+  if (prev.hblkhd != curr.hblkhd) {
+    (*oss) << "[" << name << "] "
+           << "Space allocated in mmapped regions (bytes): " << curr.hblkhd
+           << ", diff: " << ((int64_t)curr.hblkhd - (int64_t)prev.hblkhd);
+  }
+  if (prev.usmblks != curr.usmblks) {
+    (*oss) << "[" << name << "] "
+           << "Maximum total allocated space (bytes): " << curr.usmblks
+           << ", diff: "
+           << ((int64_t)curr.usmblks - (int64_t)prev.usmblks);
+  }
+  if (prev.fsmblks != curr.fsmblks) {
+    (*oss) << "[" << name << "] "
+           << "Space in freed fastbin blocks (bytes): " << curr.fsmblks
+           << ", diff: "
+           << ((int64_t)curr.fsmblks - (int64_t)prev.fsmblks);
+  }
+  if (prev.uordblks != curr.uordblks) {
+    (*oss) << "[" << name << "] "
+           << "Total allocated space (bytes): " << curr.uordblks
+           << ", diff: "
+           << ((int64_t)curr.uordblks - (int64_t)prev.uordblks);
+  }
+  if (prev.fordblks != curr.fordblks) {
+    (*oss) << "[" << name << "] "
+           << "Total free space (bytes): " << curr.fordblks << ", diff: "
+           << ((int64_t)curr.fordblks - (int64_t)prev.fordblks);
+  }
+  if (prev.keepcost != curr.keepcost) {
+    (*oss) << "[" << name << "] "
+           << "Top-most, releasable space (bytes): " << curr.keepcost
+           << ", diff: "
+           << ((int64_t)curr.keepcost - (int64_t)prev.keepcost);
+  }
+  return curr;
+}
+}  // namespace
+
+AndroidMallocLogger::AndroidMallocLogger(std::ostringstream *oss,
+                                         const std::string &name) :
+  oss_(oss), name_(name) {
+  prev_ = mallinfo();
+}
+
+AndroidMallocLogger::~AndroidMallocLogger() {
+  struct mallinfo curr = mallinfo();
+  LogMallinfoChange(oss_, name_, curr, prev_);
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/android/malloc_logger.h b/mace/port/android/malloc_logger.h
new file mode 100644
index 0000000000000000000000000000000000000000..9bc7052455b1a8445fa8b0719a82c956a6436ea4
--- /dev/null
+++ b/mace/port/android/malloc_logger.h
@@ -0,0 +1,43 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_ANDROID_MALLOC_LOGGER_H_
+#define MACE_PORT_ANDROID_MALLOC_LOGGER_H_
+
+#include <malloc.h>
+
+#include <string>
+
+#include "mace/port/env.h"
+
+namespace mace {
+namespace port {
+
+class AndroidMallocLogger : public MallocLogger {
+ public:
+  explicit AndroidMallocLogger(std::ostringstream *oss,
+                               const std::string &name);
+  ~AndroidMallocLogger() override;
+
+ private:
+  std::ostringstream *oss_;
+  const std::string name_;
+  struct mallinfo prev_;
+};
+
+}  // namespace port
+}  // namespace mace
+
+
+#endif  // MACE_PORT_ANDROID_MALLOC_LOGGER_H_
diff --git a/mace/port/darwin/BUILD.bazel b/mace/port/darwin/BUILD.bazel
new file mode 100644
index 0000000000000000000000000000000000000000..987dafd16ea22f3f8b5b97052d0672f18c81c98d
--- /dev/null
+++ b/mace/port/darwin/BUILD.bazel
@@ -0,0 +1,22 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+load("//mace:mace.bzl", "if_darwin")
+
+cc_library(
+    name = "port_darwin",
+    srcs = if_darwin(glob([
+        "*.cc",
+    ])),
+    hdrs = if_darwin(glob([
+        "*.h",
+    ])),
+    deps = [
+        "//mace/port:port_base",
+        "//mace/port/posix:port_posix",
+    ],
+    alwayslink = 1,
+)
diff --git a/mace/port/darwin/env.cc b/mace/port/darwin/env.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f951e64753b9736705b67153a7ef3ba82cb72e73
--- /dev/null
+++ b/mace/port/darwin/env.cc
@@ -0,0 +1,53 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/darwin/env.h"
+
+#include <execinfo.h>
+#include <sys/time.h>
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+#include "mace/port/posix/backtrace.h"
+#include "mace/port/posix/file_system.h"
+#include "mace/port/posix/time.h"
+
+namespace mace {
+namespace port {
+
+int64_t DarwinEnv::NowMicros() {
+  return mace::port::posix::NowMicros();
+}
+
+FileSystem *DarwinEnv::GetFileSystem() {
+  return &posix_file_system_;
+}
+
+LogWriter *DarwinEnv::GetLogWriter() {
+  return &log_writer_;
+}
+
+std::vector<std::string> DarwinEnv::GetBackTraceUnsafe(int max_steps) {
+  return mace::port::posix::GetBackTraceUnsafe(max_steps);
+}
+
+Env *Env::Default() {
+  static DarwinEnv darwin_env;
+  return &darwin_env;
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/darwin/env.h b/mace/port/darwin/env.h
new file mode 100644
index 0000000000000000000000000000000000000000..667cf9f0a0e2f102c1ddc183605eea1f22dfa0c6
--- /dev/null
+++ b/mace/port/darwin/env.h
@@ -0,0 +1,43 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_DARWIN_ENV_H_
+#define MACE_PORT_DARWIN_ENV_H_
+
+#include <string>
+#include <vector>
+
+#include "mace/port/env.h"
+#include "mace/port/logger.h"
+#include "mace/port/posix/file_system.h"
+
+namespace mace {
+namespace port {
+
+class DarwinEnv : public Env {
+ public:
+  int64_t NowMicros() override;
+  FileSystem *GetFileSystem() override;
+  LogWriter *GetLogWriter() override;
+  std::vector<std::string> GetBackTraceUnsafe(int max_steps) override;
+
+ private:
+  PosixFileSystem posix_file_system_;
+  LogWriter log_writer_;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_DARWIN_ENV_H_
diff --git a/mace/port/env.cc b/mace/port/env.cc
new file mode 100644
index 0000000000000000000000000000000000000000..10ae4306f8b5d11ea2e15540539428f604d23e35
--- /dev/null
+++ b/mace/port/env.cc
@@ -0,0 +1,40 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/env.h"
+
+#include <sstream>
+
+#include "mace/utils/memory.h"
+#include "mace/public/mace.h"
+
+namespace mace {
+namespace port {
+
+MaceStatus Env::GetCpuMaxFreq(std::vector<float> *max_freqs) {
+  return MaceStatus::MACE_UNSUPPORTED;
+}
+
+MaceStatus Env::SchedSetAffinity(const std::vector<size_t> &cpu_ids) {
+  return MaceStatus::MACE_UNSUPPORTED;
+}
+
+std::unique_ptr<MallocLogger> Env::NewMallocLogger(
+      std::ostringstream *oss,
+      const std::string &name) {
+  return make_unique<MallocLogger>();
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/env.h b/mace/port/env.h
new file mode 100644
index 0000000000000000000000000000000000000000..2491f023f4ef717a96218e5542ce4942b5afe9d0
--- /dev/null
+++ b/mace/port/env.h
@@ -0,0 +1,75 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_ENV_H_
+#define MACE_PORT_ENV_H_
+
+#include <cstdint>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "mace/public/mace.h"
+
+namespace mace {
+namespace port {
+
+class MallocLogger {
+ public:
+  MallocLogger() = default;
+  virtual ~MallocLogger() = default;
+};
+
+class FileSystem;
+class LogWriter;
+
+class Env {
+ public:
+  virtual int64_t NowMicros() = 0;
+  virtual MaceStatus GetCpuMaxFreq(std::vector<float> *max_freqs);
+  virtual MaceStatus SchedSetAffinity(const std::vector<size_t> &cpu_ids);
+  virtual FileSystem *GetFileSystem() = 0;
+  virtual LogWriter *GetLogWriter() = 0;
+  // Return the current backtrace, will allocate memory inside the call
+  // which may fail
+  virtual std::vector<std::string> GetBackTraceUnsafe(int max_steps) = 0;
+  virtual std::unique_ptr<MallocLogger> NewMallocLogger(
+      std::ostringstream *oss,
+      const std::string &name);
+
+  static Env *Default();
+};
+
+}  // namespace port
+
+inline int64_t NowMicros() {
+  return port::Env::Default()->NowMicros();
+}
+
+inline MaceStatus GetCpuMaxFreq(std::vector<float> *max_freqs) {
+  return port::Env::Default()->GetCpuMaxFreq(max_freqs);
+}
+
+inline MaceStatus SchedSetAffinity(const std::vector<size_t> &cpu_ids) {
+  return port::Env::Default()->SchedSetAffinity(cpu_ids);
+}
+
+inline port::FileSystem *GetFileSystem() {
+  return port::Env::Default()->GetFileSystem();
+}
+
+}  // namespace mace
+
+#endif  // MACE_PORT_ENV_H_
diff --git a/mace/port/env_test.cc b/mace/port/env_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..1a61554522c6240fb80795aadebb16de6857f42d
--- /dev/null
+++ b/mace/port/env_test.cc
@@ -0,0 +1,41 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/env.h"
+
+#include <gtest/gtest.h>
+
+namespace mace {
+namespace {
+
+class EnvTest : public ::testing::Test {
+};
+
+TEST_F(EnvTest, NowMicros) {
+  EXPECT_GT(NowMicros(), 0);
+}
+
+TEST_F(EnvTest, GetFileSystem) {
+  GetFileSystem();
+}
+
+TEST_F(EnvTest, CpuInfo) {
+  std::vector<float> freq;
+  GetCpuMaxFreq(&freq);
+  std::vector<size_t> cpu_ids;
+  SchedSetAffinity(cpu_ids);
+}
+
+}  // namespace
+}  // namespace mace
diff --git a/mace/port/file_system.h b/mace/port/file_system.h
new file mode 100644
index 0000000000000000000000000000000000000000..91b6f458d3a021c9163e7cc07c1404805f2aae43
--- /dev/null
+++ b/mace/port/file_system.h
@@ -0,0 +1,45 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_FILE_SYSTEM_H_
+#define MACE_PORT_FILE_SYSTEM_H_
+
+#include <string>
+#include <memory>
+
+#include "mace/public/mace.h"
+
+namespace mace {
+namespace port {
+
+class ReadOnlyMemoryRegion {
+ public:
+  ReadOnlyMemoryRegion() = default;
+  virtual ~ReadOnlyMemoryRegion() = default;
+  virtual const void *data() = 0;
+  virtual uint64_t length() = 0;
+};
+
+class FileSystem {
+ public:
+  FileSystem() = default;
+  virtual ~FileSystem() = default;
+  virtual MaceStatus NewReadOnlyMemoryRegionFromFile(const char *fname,
+      std::unique_ptr<ReadOnlyMemoryRegion>* result) = 0;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_FILE_SYSTEM_H_
diff --git a/mace/port/linux/BUILD.bazel b/mace/port/linux/BUILD.bazel
new file mode 100644
index 0000000000000000000000000000000000000000..5d1351baf844c4e90f6259fddb97b6217dd769b2
--- /dev/null
+++ b/mace/port/linux/BUILD.bazel
@@ -0,0 +1,22 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+load("//mace:mace.bzl", "if_linux")
+
+cc_library(
+    name = "port_linux",
+    srcs = if_linux(glob([
+        "*.cc",
+    ])),
+    hdrs = if_linux(glob([
+        "*.h",
+    ])),
+    deps = [
+        "//mace/port:port_base",
+        "//mace/port/posix:port_posix",
+    ],
+    alwayslink = 1,
+)
diff --git a/mace/port/linux/env.cc b/mace/port/linux/env.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2a50b4a1198049d5610f3daad5b33f47efb97c4a
--- /dev/null
+++ b/mace/port/linux/env.cc
@@ -0,0 +1,53 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/linux/env.h"
+
+#include <execinfo.h>
+#include <sys/time.h>
+
+#include <cstddef>
+#include <string>
+#include <vector>
+
+#include "mace/port/posix/backtrace.h"
+#include "mace/port/posix/file_system.h"
+#include "mace/port/posix/time.h"
+
+namespace mace {
+namespace port {
+
+int64_t LinuxEnv::NowMicros() {
+  return mace::port::posix::NowMicros();
+}
+
+FileSystem *LinuxEnv::GetFileSystem() {
+  return &posix_file_system_;
+}
+
+LogWriter *LinuxEnv::GetLogWriter() {
+  return &log_writer_;
+}
+
+std::vector<std::string> LinuxEnv::GetBackTraceUnsafe(int max_steps) {
+  return mace::port::posix::GetBackTraceUnsafe(max_steps);
+}
+
+Env *Env::Default() {
+  static LinuxEnv linux_env;
+  return &linux_env;
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/linux/env.h b/mace/port/linux/env.h
new file mode 100644
index 0000000000000000000000000000000000000000..5d1d243a1ab616c3bf13d6d9069147e7cced4519
--- /dev/null
+++ b/mace/port/linux/env.h
@@ -0,0 +1,43 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_LINUX_ENV_H_
+#define MACE_PORT_LINUX_ENV_H_
+
+#include <string>
+#include <vector>
+
+#include "mace/port/env.h"
+#include "mace/port/logger.h"
+#include "mace/port/posix/file_system.h"
+
+namespace mace {
+namespace port {
+
+class LinuxEnv : public Env {
+ public:
+  int64_t NowMicros() override;
+  FileSystem *GetFileSystem() override;
+  LogWriter *GetLogWriter() override;
+  std::vector<std::string> GetBackTraceUnsafe(int max_steps) override;
+
+ private:
+  PosixFileSystem posix_file_system_;
+  LogWriter log_writer_;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_LINUX_ENV_H_
diff --git a/mace/port/logger.cc b/mace/port/logger.cc
new file mode 100644
index 0000000000000000000000000000000000000000..b02f6f4455d92a275470c0c762edf20c257d2b38
--- /dev/null
+++ b/mace/port/logger.cc
@@ -0,0 +1,115 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/logger.h"
+
+#include <cstdlib>
+#include <iomanip>
+#include <string>
+#include <vector>
+
+#include "mace/port/env.h"
+#include "mace/utils/string_util.h"
+
+namespace mace {
+namespace port {
+
+inline bool IsValidLogLevel(const LogLevel level) {
+  return level > LogLevel::INVALID_MIN &&
+         level < LogLevel::INVALID_MAX;
+}
+
+LogLevel LogLevelFromStr(const char *log_level_str) {
+  if (log_level_str != nullptr) {
+    std::string ls = ToUpper(log_level_str);
+
+    if (ls == "I" || ls == "INFO") {
+      return LogLevel::INFO;
+    }
+    if (ls == "W" || ls == "WARNING") {
+      return LogLevel::WARNING;
+    }
+    if (ls == "E" || ls == "ERROR") {
+      return LogLevel::ERROR;
+    }
+    if (ls == "F" || ls == "FATAL") {
+      return LogLevel::FATAL;
+    }
+  }
+
+  return LogLevel::INVALID_MIN;
+}
+
+char LogLevelToShortStr(LogLevel level) {
+  if (!IsValidLogLevel(level)) {
+    level = LogLevel::INFO;
+  }
+
+  return "IWEF"[static_cast<int>(level) - 1];
+}
+
+int VLogLevelFromStr(const char *vlog_level_str) {
+  if (vlog_level_str != nullptr) {
+    return atoi(vlog_level_str);
+  }
+
+  return 0;
+}
+
+
+void LogWriter::WriteLogMessage(const char *fname,
+                                const int line,
+                                const LogLevel severity,
+                                const char *message) {
+  printf("%c %s:%d] %s\n", LogLevelToShortStr(severity), fname, line, message);
+}
+
+Logger::Logger(const char *fname, int line, LogLevel severity)
+    : fname_(fname), line_(line), severity_(severity) {}
+
+void Logger::GenerateLogMessage() {
+  LogWriter *log_writer = Env::Default()->GetLogWriter();
+  log_writer->WriteLogMessage(fname_, line_, severity_, str().c_str());
+
+  // When there is a fatal log, terminate execution
+  if (severity_ == LogLevel::FATAL) {
+    DealWithFatal();
+  }
+}
+
+void Logger::DealWithFatal() {
+  // When there is a fatal log, log the backtrace and abort.
+  LogWriter *log_writer = Env::Default()->GetLogWriter();
+  std::vector<std::string> bt = Env::Default()->GetBackTraceUnsafe(50);
+  if (!bt.empty()) {
+    log_writer->WriteLogMessage(fname_, line_, severity_, "backtrace:");
+    for (size_t i = 0; i < bt.size(); ++i) {
+      std::ostringstream os;
+      os << " " << bt[i];
+      log_writer->WriteLogMessage(fname_, line_, severity_, os.str().c_str());
+    }
+  }
+
+  abort();
+}
+
+Logger::~Logger() {
+  static const LogLevel min_log_level = MinLogLevelFromEnv();
+  if (LogLevelPassThreashold(severity_, min_log_level)) {
+    GenerateLogMessage();
+  }
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/logger.h b/mace/port/logger.h
new file mode 100644
index 0000000000000000000000000000000000000000..08bcbbe4a8c3447332d897d602e05d9a38f6659e
--- /dev/null
+++ b/mace/port/logger.h
@@ -0,0 +1,95 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_LOGGER_H_
+#define MACE_PORT_LOGGER_H_
+
+#include <cstdlib>
+#include <cstring>
+#include <sstream>
+
+namespace mace {
+
+enum LogLevel {
+  INVALID_MIN = 0,
+  INFO        = 1,
+  WARNING     = 2,
+  ERROR       = 3,
+  FATAL       = 4,
+  INVALID_MAX,
+};
+
+namespace port {
+
+inline bool LogLevelPassThreashold(const LogLevel level,
+                                   const LogLevel threshold) {
+  return level >= threshold;
+}
+
+LogLevel LogLevelFromStr(const char *log_level_str);
+int VLogLevelFromStr(const char *vlog_level_str);
+
+inline LogLevel MinLogLevelFromEnv() {
+  // Read the min log level from env once during the first call to logging.
+  static LogLevel log_level = LogLevelFromStr(getenv("MACE_CPP_MIN_LOG_LEVEL"));
+  return log_level;
+}
+
+inline int MinVLogLevelFromEnv() {
+  // Read the min vlog level from env once during the first call to logging.
+  static int vlog_level = VLogLevelFromStr(getenv("MACE_CPP_MIN_VLOG_LEVEL"));
+  return vlog_level;
+}
+
+class LogWriter {
+ public:
+  LogWriter() = default;
+  virtual ~LogWriter() = default;
+  virtual void WriteLogMessage(const char *fname,
+                               const int line,
+                               const LogLevel severity,
+                               const char *message);
+};
+
+class Logger : public std::ostringstream {
+ public:
+  Logger(const char *fname, int line, LogLevel severity);
+  ~Logger();
+
+ private:
+  void GenerateLogMessage();
+  void DealWithFatal();
+
+  const char *fname_;
+  int line_;
+  LogLevel severity_;
+};
+
+}  // namespace port
+
+// Whether the log level pass the env configured threshold, can be used for
+// short cutting.
+inline bool ShouldGenerateLogMessage(LogLevel severity) {
+  LogLevel threshold = port::MinLogLevelFromEnv();
+  return port::LogLevelPassThreashold(severity, threshold);
+}
+
+inline bool ShouldGenerateVLogMessage(int vlog_level) {
+  int threshold = port::MinVLogLevelFromEnv();
+  return ShouldGenerateLogMessage(INFO) &&
+         vlog_level <= threshold;
+}
+}  // namespace mace
+
+#endif  // MACE_PORT_LOGGER_H_
diff --git a/mace/port/logger_test.cc b/mace/port/logger_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..93df626ba8a2d61821dd68f07b3a3823fff8a5de
--- /dev/null
+++ b/mace/port/logger_test.cc
@@ -0,0 +1,44 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/logger.h"
+
+#include <gtest/gtest.h>
+
+namespace mace {
+namespace {
+
+class LoggerTest : public ::testing::Test {
+};
+
+TEST_F(LoggerTest, LogLevel) {
+  EXPECT_EQ(INFO, port::LogLevelFromStr("i"));
+  EXPECT_EQ(INFO, port::LogLevelFromStr("I"));
+  EXPECT_EQ(INFO, port::LogLevelFromStr("INFO"));
+
+  EXPECT_EQ(WARNING, port::LogLevelFromStr("w"));
+  EXPECT_EQ(WARNING, port::LogLevelFromStr("W"));
+  EXPECT_EQ(WARNING, port::LogLevelFromStr("WARNING"));
+
+  EXPECT_EQ(ERROR, port::LogLevelFromStr("e"));
+  EXPECT_EQ(ERROR, port::LogLevelFromStr("E"));
+  EXPECT_EQ(ERROR, port::LogLevelFromStr("ERROR"));
+
+  EXPECT_EQ(FATAL, port::LogLevelFromStr("f"));
+  EXPECT_EQ(FATAL, port::LogLevelFromStr("F"));
+  EXPECT_EQ(FATAL, port::LogLevelFromStr("FATAL"));
+}
+
+}  // namespace
+}  // namespace mace
diff --git a/mace/port/posix/BUILD.bazel b/mace/port/posix/BUILD.bazel
new file mode 100644
index 0000000000000000000000000000000000000000..321a18a516d88749bde3e5cf2677fda941f12480
--- /dev/null
+++ b/mace/port/posix/BUILD.bazel
@@ -0,0 +1,19 @@
+package(
+    default_visibility = ["//visibility:public"],
+)
+
+licenses(["notice"])  # Apache 2.0
+
+cc_library(
+    name = "port_posix",
+    srcs = glob([
+        "*.cc",
+    ]),
+    hdrs = glob([
+        "*.h",
+    ]),
+    deps = [
+        "//mace/port:port_base",
+        "//mace/utils",
+    ],
+)
diff --git a/mace/port/posix/backtrace.h b/mace/port/posix/backtrace.h
new file mode 100644
index 0000000000000000000000000000000000000000..d96419319f874b34149a25493ca44ecd22680976
--- /dev/null
+++ b/mace/port/posix/backtrace.h
@@ -0,0 +1,45 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_POSIX_BACKTRACE_H_
+#define MACE_PORT_POSIX_BACKTRACE_H_
+
+#include <execinfo.h>
+
+#include <string>
+#include <vector>
+
+namespace mace {
+namespace port {
+namespace posix {
+
+inline std::vector<std::string> GetBackTraceUnsafe(int max_steps) {
+  std::vector<void *> buffer(max_steps, 0);
+  int steps = backtrace(buffer.data(), max_steps);
+
+  std::vector<std::string> bt;
+  char **symbols = backtrace_symbols(buffer.data(), steps);
+  if (symbols != nullptr) {
+    for (int i = 0; i < steps; i++) {
+      bt.push_back(symbols[i]);
+    }
+  }
+  return bt;
+}
+
+}  // namespace posix
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_POSIX_BACKTRACE_H_
diff --git a/mace/port/posix/file_system.cc b/mace/port/posix/file_system.cc
new file mode 100644
index 0000000000000000000000000000000000000000..236f221530c0d5d1be54dadf1c561f12edc6a560
--- /dev/null
+++ b/mace/port/posix/file_system.cc
@@ -0,0 +1,73 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/port/posix/file_system.h"
+
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <memory>
+#include <string>
+
+#include "mace/utils/memory.h"
+
+namespace mace {
+namespace port {
+
+namespace {
+class PosixReadOnlyMemoryRegion : public ReadOnlyMemoryRegion {
+ public:
+  PosixReadOnlyMemoryRegion() = delete;
+  PosixReadOnlyMemoryRegion(const void* addr, uint64_t length)
+    : addr_(addr), length_(length) {}
+  ~PosixReadOnlyMemoryRegion() override {
+    munmap(const_cast<void *>(addr_), length_);
+  };
+  const void *data() override { return addr_; };
+  uint64_t length() override { return length_; };
+
+ private:
+  const void *addr_;
+  const uint64_t length_;
+};
+}  // namespace
+
+MaceStatus PosixFileSystem::NewReadOnlyMemoryRegionFromFile(
+    const char *fname,
+    std::unique_ptr<ReadOnlyMemoryRegion>* result) {
+  MaceStatus s = MaceStatus(MaceStatus::MACE_SUCCESS);
+  int fd = open(fname, O_RDONLY);
+  if (fd < 0) {
+    // TODO(heliangliang) check errno
+    s = MaceStatus(MaceStatus::MACE_RUNTIME_ERROR);
+  } else {
+    struct stat st;
+    fstat(fd, &st);
+    const void* address =
+        mmap(nullptr, st.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
+    if (address == MAP_FAILED) {
+      // TODO(heliangliang) check errno
+      s = MaceStatus(MaceStatus::MACE_RUNTIME_ERROR);
+    } else {
+      *result = make_unique<PosixReadOnlyMemoryRegion>(address, st.st_size);
+    }
+    close(fd);
+  }
+  return s;
+}
+
+}  // namespace port
+}  // namespace mace
diff --git a/mace/port/posix/file_system.h b/mace/port/posix/file_system.h
new file mode 100644
index 0000000000000000000000000000000000000000..8eb370757fcce9a558b993ac7f80e2d0ca1d2024
--- /dev/null
+++ b/mace/port/posix/file_system.h
@@ -0,0 +1,37 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_PORT_POSIX_FILE_SYSTEM_H_
+#define MACE_PORT_POSIX_FILE_SYSTEM_H_
+
+#include <string>
+#include <memory>
+
+#include "mace/port/file_system.h"
+
+namespace mace {
+namespace port {
+
+class PosixFileSystem : public FileSystem {
+ public:
+  PosixFileSystem() = default;
+  ~PosixFileSystem() override = default;
+  MaceStatus NewReadOnlyMemoryRegionFromFile(const char *fname,
+      std::unique_ptr<ReadOnlyMemoryRegion>* result) override;
+};
+
+}  // namespace port
+}  // namespace mace
+
+#endif  // MACE_PORT_POSIX_FILE_SYSTEM_H_
diff --git a/mace/utils/env_time.h b/mace/port/posix/time.h
similarity index 72%
rename from mace/utils/env_time.h
rename to mace/port/posix/time.h
index 18d6e5a6ad6229284a2ae2e3e2fbbeb50fc952d7..84ab478a9580ad67618d53517a8f87afc4f2699b 100644
--- a/mace/utils/env_time.h
+++ b/mace/port/posix/time.h
@@ -1,4 +1,4 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
+// Copyright 2019 The MACE Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,28 +12,25 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef MACE_UTILS_ENV_TIME_H_
-#define MACE_UTILS_ENV_TIME_H_
+#ifndef MACE_PORT_POSIX_TIME_H_
+#define MACE_PORT_POSIX_TIME_H_
 
-#include <stdint.h>
-#ifdef __hexagon__
-#include <HAP_perf.h>
-#else
 #include <sys/time.h>
-#endif
+
+#include <cstddef>
 
 namespace mace {
+namespace port {
+namespace posix {
 
 inline int64_t NowMicros() {
-#ifdef __hexagon__
-  return HAP_perf_get_time_us();
-#else
   struct timeval tv;
   gettimeofday(&tv, nullptr);
   return static_cast<int64_t>(tv.tv_sec) * 1000000 + tv.tv_usec;
-#endif
 }
 
+}  // namespace posix
+}  // namespace port
 }  // namespace mace
 
-#endif  // MACE_UTILS_ENV_TIME_H_
+#endif  // MACE_PORT_POSIX_TIME_H_
diff --git a/mace/proto/BUILD b/mace/proto/BUILD.bazel
similarity index 100%
rename from mace/proto/BUILD
rename to mace/proto/BUILD.bazel
diff --git a/mace/public/BUILD b/mace/public/BUILD.bazel
similarity index 87%
rename from mace/public/BUILD
rename to mace/public/BUILD.bazel
index b434312bcfdd4ec65a78bfc879a2dfcb41cc129c..158bc564dff7c4118ff368d0dfd1cb6a0eb0547f 100644
--- a/mace/public/BUILD
+++ b/mace/public/BUILD.bazel
@@ -12,5 +12,8 @@ cc_library(
     hdrs = [
         "mace.h",
     ],
+    srcs = [
+        "status.cc",
+    ],
     copts = ["-Werror", "-Wextra", "-Wno-missing-field-initializers"],
 )
diff --git a/mace/public/mace.h b/mace/public/mace.h
index d71ecc1b4d0935958465ea37507a2ac32524c280..3d210d3801bd899a5ad27951f61a898648845096 100644
--- a/mace/public/mace.h
+++ b/mace/public/mace.h
@@ -144,7 +144,9 @@ class MaceStatus {
   enum Code {
     MACE_SUCCESS = 0,
     MACE_INVALID_ARGS = 1,
-    MACE_OUT_OF_RESOURCES = 2
+    MACE_OUT_OF_RESOURCES = 2,
+    MACE_UNSUPPORTED = 3,
+    MACE_RUNTIME_ERROR = 4,
   };
 
  public:
@@ -167,18 +169,6 @@ class MaceStatus {
   std::unique_ptr<Impl> impl_;
 };
 
-
-#define MACE_RETURN_IF_ERROR(stmt)                                         \
-  {                                                                        \
-    MaceStatus status = (stmt);                                            \
-    if (status != MaceStatus::MACE_SUCCESS) {                              \
-      VLOG(0) << "Mace runtime failure: "                                  \
-              << __FILE__ << ":" << __LINE__ << ". "                       \
-              << status.information();                                     \
-      return status;                                                       \
-    }                                                                      \
-  }
-
 /// \brief GPU context contain the status used for GPU device.
 ///
 /// There are some data in common between different MaceEngines using GPU,
diff --git a/mace/core/status.cc b/mace/public/status.cc
similarity index 86%
rename from mace/core/status.cc
rename to mace/public/status.cc
index 12134f88a73940e26c8eb6c70a65011dcb25d647..c377c9b64112750bd9e46f53bdccf664b1aa8ca3 100644
--- a/mace/core/status.cc
+++ b/mace/public/status.cc
@@ -12,6 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <sstream>
+
 #include "mace/public/mace.h"
 
 namespace mace {
@@ -26,10 +28,16 @@ class MaceStatus::Impl {
   void SetCode(const Code code) { code_ = code; }
   Code code() const { return code_; }
   void SetInformation(const std::string &info) { information_ = info; }
-  std::string information() const { return Code2Str() + ": " + information_; }
+  std::string information() const {
+    if (information_.empty()) {
+      return CodeToString();
+    } else {
+      return CodeToString() + ": " + information_;
+    }
+  }
 
  private:
-  std::string Code2Str() const {
+  std::string CodeToString() const {
     switch (code_) {
       case MaceStatus::MACE_SUCCESS:
         return "Success";
@@ -37,8 +45,14 @@ class MaceStatus::Impl {
         return "Invalid Arguments";
       case MaceStatus::MACE_OUT_OF_RESOURCES:
         return "Out of resources";
+      case MACE_UNSUPPORTED:
+        return "Unsupported";
+      case MACE_RUNTIME_ERROR:
+        return "Runtime error";
       default:
-        return "";
+        std::ostringstream os;
+        os << code_;
+        return os.str();
     }
   }
 
diff --git a/mace/python/tools/BUILD b/mace/python/tools/BUILD.bazel
similarity index 100%
rename from mace/python/tools/BUILD
rename to mace/python/tools/BUILD.bazel
diff --git a/mace/python/tools/model.jinja2 b/mace/python/tools/model.jinja2
index 1beae21ab41ca1fc583fbd016b4e6d8430ad2ff9..c7d936c0318527423e8b251b06647048c446a17a 100644
--- a/mace/python/tools/model.jinja2
+++ b/mace/python/tools/model.jinja2
@@ -16,10 +16,10 @@
 
 #include <string>
 
-#include "mace/core/macros.h"
+#include "mace/utils/macros.h"
 #include "mace/proto/mace.pb.h"
 #include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/python/tools/operator.jinja2 b/mace/python/tools/operator.jinja2
index 8992da31ef7c9468b723d362ac04ab98511593f5..b184b54a3d98f034147866d04a6b48c1af0703f9 100644
--- a/mace/python/tools/operator.jinja2
+++ b/mace/python/tools/operator.jinja2
@@ -19,7 +19,7 @@
 
 #include "mace/proto/mace.pb.h"
 #include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/python/tools/tensor_source.jinja2 b/mace/python/tools/tensor_source.jinja2
index 77d91eab6aff431549b8e848369503944d52d5d3..d459d9bc806d23f7cb49ad90ba72f2a753dfd886 100644
--- a/mace/python/tools/tensor_source.jinja2
+++ b/mace/python/tools/tensor_source.jinja2
@@ -16,7 +16,7 @@
 
 #include "mace/proto/mace.pb.h"
 #include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/python/tools/visualization/BUILD b/mace/python/tools/visualization/BUILD.bazel
similarity index 100%
rename from mace/python/tools/visualization/BUILD
rename to mace/python/tools/visualization/BUILD.bazel
diff --git a/mace/test/BUILD b/mace/test/BUILD.bazel
similarity index 100%
rename from mace/test/BUILD
rename to mace/test/BUILD.bazel
diff --git a/mace/tools/validation/BUILD b/mace/tools/validation/BUILD.bazel
similarity index 100%
rename from mace/tools/validation/BUILD
rename to mace/tools/validation/BUILD.bazel
diff --git a/mace/tools/validation/mace_run.cc b/mace/tools/validation/mace_run.cc
index 947255e5cbd9af8a3f064277ee38b0fd3d3c510c..d7a911a07f8073e2ea907e58f182af96128637ef 100644
--- a/mace/tools/validation/mace_run.cc
+++ b/mace/tools/validation/mace_run.cc
@@ -24,8 +24,7 @@
  *          --model_data_file=model_data.data \
  *          --device=GPU
  */
-#include <malloc.h>
-#include <stdint.h>
+#include <cstdint>
 #include <cstdio>
 #include <cstdlib>
 #include <fstream>
@@ -34,9 +33,9 @@
 
 #include "gflags/gflags.h"
 #include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
-#include "mace/utils/utils.h"
+#include "mace/utils/string_util.h"
 
 #ifdef MODEL_GRAPH_FORMAT_CODE
 #include "mace/codegen/engine/mace_engine_factory.h"
@@ -46,29 +45,6 @@ namespace mace {
 namespace tools {
 namespace validation {
 
-namespace str_util {
-
-std::vector<std::string> Split(const std::string &str, char delims) {
-  std::vector<std::string> result;
-  if (str.empty()) {
-    result.push_back("");
-    return result;
-  }
-  std::string tmp = str;
-  while (!tmp.empty()) {
-    size_t next_offset = tmp.find(delims);
-    result.push_back(tmp.substr(0, next_offset));
-    if (next_offset == std::string::npos) {
-      break;
-    } else {
-      tmp = tmp.substr(next_offset + 1);
-    }
-  }
-  return result;
-}
-
-}  // namespace str_util
-
 void ParseShape(const std::string &str, std::vector<int64_t> *shape) {
   std::string tmp = str;
   while (!tmp.empty()) {
@@ -500,13 +476,10 @@ int Main(int argc, char **argv) {
   LOG(INFO) << "omp_num_threads: " << FLAGS_omp_num_threads;
   LOG(INFO) << "cpu_affinity_policy: " << FLAGS_cpu_affinity_policy;
 
-  std::vector<std::string> input_names = str_util::Split(FLAGS_input_node, ',');
-  std::vector<std::string> output_names =
-      str_util::Split(FLAGS_output_node, ',');
-  std::vector<std::string> input_shapes =
-      str_util::Split(FLAGS_input_shape, ':');
-  std::vector<std::string> output_shapes =
-      str_util::Split(FLAGS_output_shape, ':');
+  std::vector<std::string> input_names = Split(FLAGS_input_node, ',');
+  std::vector<std::string> output_names = Split(FLAGS_output_node, ',');
+  std::vector<std::string> input_shapes = Split(FLAGS_input_shape, ':');
+  std::vector<std::string> output_shapes = Split(FLAGS_output_shape, ':');
 
   const size_t input_count = input_shapes.size();
   const size_t output_count = output_shapes.size();
diff --git a/mace/utils/BUILD b/mace/utils/BUILD.bazel
similarity index 61%
rename from mace/utils/BUILD
rename to mace/utils/BUILD.bazel
index 4388e1a6628de7f738cb2a971d9a9c8f29022bd3..56b794378da9ad53716cb5c52753f44b231373f7 100644
--- a/mace/utils/BUILD
+++ b/mace/utils/BUILD.bazel
@@ -7,12 +7,6 @@ package(
 
 licenses(["notice"])  # Apache 2.0
 
-load(
-    "//mace:mace.bzl",
-    "if_android",
-    "if_openmp_enabled",
-)
-
 cc_library(
     name = "utils",
     srcs = glob(
@@ -20,7 +14,7 @@ cc_library(
             "*.cc",
         ],
         exclude = [
-            "tuner_test.cc",
+            "*_test.cc",
         ],
     ),
     hdrs = glob([
@@ -30,36 +24,30 @@ cc_library(
         "-Werror",
         "-Wextra",
         "-Wno-missing-field-initializers",
-    ] + if_openmp_enabled([
-        "-fopenmp",
-    ]),
-    linkopts = if_android([
-        "-llog",
-    ]),
+    ],
     deps = [
+        "//mace/port:port_api",
         "//mace/public",
     ],
 )
 
 cc_test(
-    name = "tuner_test",
+    name = "utils_test",
     testonly = 1,
-    srcs = [
-        "tuner_test.cc",
-    ],
+    srcs = glob(
+        [
+            "*_test.cc",
+        ],
+    ),
     copts = [
         "-Werror",
         "-Wextra",
         "-Wno-missing-field-initializers",
     ],
-    linkopts = ["-ldl"] + if_android([
-        "-pie",
-        "-lm",  # Required by unordered_map
-    ]),
-    linkstatic = 1,
+    linkstatic = 0,
     deps = [
         ":utils",
-        "//mace/core",
+        "//mace/port",
         "@gtest//:gtest",
         "@gtest//:gtest_main",
     ],
diff --git a/mace/utils/conf_util.h b/mace/utils/conf_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..4800b15e24d47c3690531a94f52214616c710624
--- /dev/null
+++ b/mace/utils/conf_util.h
@@ -0,0 +1,33 @@
+// Copyright 2018 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_UTILS_CONF_UTIL_H_
+#define MACE_UTILS_CONF_UTIL_H_
+
+#include <algorithm>
+#include <cstdlib>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace mace {
+
+inline bool EnvConfEnabled(std::string env_name) {
+  char *env = getenv(env_name.c_str());
+  return !(!env || env[0] == 0 || env[0] == '0');
+}
+
+}  // namespace mace
+
+#endif  // MACE_UTILS_CONF_UTIL_H_
diff --git a/mace/utils/detection_output.cc b/mace/utils/detection_output.cc
deleted file mode 100644
index 10a4f4f0903e65d3d11ff53051b61f4a15dc1756..0000000000000000000000000000000000000000
--- a/mace/utils/detection_output.cc
+++ /dev/null
@@ -1,159 +0,0 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include <algorithm>
-#include <cmath>
-#include <functional>
-#include <memory>
-#include <utility>
-#include <vector>
-
-#include "mace/utils/logging.h"
-
-namespace mace {
-
-struct BBox {
-  float xmin;
-  float ymin;
-  float xmax;
-  float ymax;
-  int label;
-  float confidence;
-};
-
-namespace {
-inline float overlap(const BBox &a, const BBox &b) {
-  if (a.xmin > b.xmax || a.xmax < b.xmin ||
-      a.ymin > b.ymax || a.ymax < b.ymin) {
-    return 0.f;
-  }
-  float overlap_w = std::min(a.xmax, b.xmax) - std::max(a.xmin, b.xmin);
-  float overlap_h = std::min(a.ymax, b.ymax) - std::max(a.ymin, b.ymin);
-  return overlap_w * overlap_h;
-}
-
-void NmsSortedBboxes(const std::vector<BBox> &bboxes,
-                     const float nms_threshold,
-                     const int top_k,
-                     std::vector<BBox> *sorted_boxes) {
-  const int n = std::min(top_k, static_cast<int>(bboxes.size()));
-  std::vector<int> picked;
-
-  std::vector<float> areas(n);
-#pragma omp parallel for schedule(runtime)
-  for (int i = 0; i < n; ++i) {
-    const BBox &r = bboxes[i];
-    float width = std::max(0.f, r.xmax - r.xmin);
-    float height = std::max(0.f, r.ymax - r.ymin);
-    areas[i] = width * height;
-  }
-
-  for (int i = 0; i < n; ++i) {
-    const BBox &a = bboxes[i];
-    int keep = 1;
-    for (size_t j = 0; j < picked.size(); ++j) {
-      const BBox &b = bboxes[picked[j]];
-
-      float inter_area = overlap(a, b);
-      float union_area = areas[i] + areas[picked[j]] - inter_area;
-      MACE_CHECK(union_area > 0, "union_area should be greater than 0");
-      if (inter_area / union_area > nms_threshold) {
-        keep = 0;
-        break;
-      }
-    }
-
-    if (keep) {
-      picked.push_back(i);
-      sorted_boxes->push_back(bboxes[i]);
-    }
-  }
-}
-
-inline bool cmp(const BBox &a, const BBox &b) {
-  return a.confidence > b.confidence;
-}
-}  // namespace
-
-int DetectionOutput(const float *loc_ptr,
-                    const float *conf_ptr,
-                    const float *pbox_ptr,
-                    const int num_prior,
-                    const int num_classes,
-                    const float nms_threshold,
-                    const int top_k,
-                    const int keep_top_k,
-                    const float confidence_threshold,
-                    std::vector<BBox> *bbox_rects) {
-  MACE_CHECK(keep_top_k > 0, "keep_top_k should be greater than 0");
-  std::vector<float> bboxes(4 * num_prior);
-#pragma omp parallel for schedule(runtime)
-  for (int i = 0; i < num_prior; ++i) {
-    int index = i * 4;
-    const float *lc = loc_ptr + index;
-    const float *pb = pbox_ptr + index;
-    const float *var = pb + num_prior * 4;
-
-    float pb_w = pb[2] - pb[0];
-    float pb_h = pb[3] - pb[1];
-    float pb_cx = (pb[0] + pb[2]) * 0.5f;
-    float pb_cy = (pb[1] + pb[3]) * 0.5f;
-
-    float bbox_cx = var[0] * lc[0] * pb_w + pb_cx;
-    float bbox_cy = var[1] * lc[1] * pb_h + pb_cy;
-    float bbox_w = std::exp(var[2] * lc[2]) * pb_w;
-    float bbox_h = std::exp(var[3] * lc[3]) * pb_h;
-
-    bboxes[0 + index] = bbox_cx - bbox_w * 0.5f;
-    bboxes[1 + index] = bbox_cy - bbox_h * 0.5f;
-    bboxes[2 + index] = bbox_cx + bbox_w * 0.5f;
-    bboxes[3 + index] = bbox_cy + bbox_h * 0.5f;
-  }
-  // start from 1 to ignore background class
-
-  for (int i = 1; i < num_classes; ++i) {
-    // filter by confidence threshold
-    std::vector<BBox> class_bbox_rects;
-    for (int j = 0; j < num_prior; ++j) {
-      float confidence = conf_ptr[j * num_classes + i];
-      if (confidence > confidence_threshold) {
-        BBox c = {bboxes[0 + j * 4], bboxes[1 + j * 4], bboxes[2 + j * 4],
-                  bboxes[3 + j * 4], i, confidence};
-        class_bbox_rects.push_back(c);
-      }
-    }
-    std::sort(class_bbox_rects.begin(), class_bbox_rects.end(), cmp);
-
-    // apply nms
-    std::vector<BBox> sorted_boxes;
-    NmsSortedBboxes(class_bbox_rects,
-                    nms_threshold,
-                    std::min(top_k,
-                             static_cast<int>(class_bbox_rects.size())),
-                    &sorted_boxes);
-    // gather
-    bbox_rects->insert(bbox_rects->end(), sorted_boxes.begin(),
-                       sorted_boxes.end());
-  }
-
-  std::sort(bbox_rects->begin(), bbox_rects->end(), cmp);
-
-  // output
-  int num_detected = keep_top_k < static_cast<int>(bbox_rects->size()) ?
-                     keep_top_k : static_cast<int>(bbox_rects->size());
-  bbox_rects->resize(num_detected);
-
-  return num_detected;
-}
-}  // namespace mace
diff --git a/mace/utils/logging.cc b/mace/utils/logging.cc
deleted file mode 100644
index 8091f0a0148e8f1d68f7c88858585d51f232dd8a..0000000000000000000000000000000000000000
--- a/mace/utils/logging.cc
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "mace/utils/logging.h"
-
-#include <stdlib.h>
-#include <string.h>
-#include <sstream>
-#if defined(ANDROID) || defined(__ANDROID__)
-#include <android/log.h>
-#include <iostream>
-#endif
-
-namespace mace {
-namespace logging {
-
-LogMessage::LogMessage(const char *fname, int line, int severity)
-    : fname_(fname), line_(line), severity_(severity) {}
-
-void LogMessage::DealWithFatal() {
-  // When there is a fatal log, now we simply abort.
-  abort();
-}
-
-void LogMessage::GenerateLogMessage() {
-#if defined(ANDROID) || defined(__ANDROID__)
-  int android_log_level;
-  switch (severity_) {
-    case INFO:
-      android_log_level = ANDROID_LOG_INFO;
-      break;
-    case WARNING:
-      android_log_level = ANDROID_LOG_WARN;
-      break;
-    case ERROR:
-      android_log_level = ANDROID_LOG_ERROR;
-      break;
-    case FATAL:
-      android_log_level = ANDROID_LOG_FATAL;
-      break;
-    default:
-      if (severity_ < INFO) {
-        android_log_level = ANDROID_LOG_VERBOSE;
-      } else {
-        android_log_level = ANDROID_LOG_ERROR;
-      }
-      break;
-  }
-
-  std::stringstream ss;
-  const char *const partial_name = strrchr(fname_, '/');
-  ss << (partial_name != nullptr ? partial_name + 1 : fname_) << ":" << line_
-     << " " << str();
-  __android_log_write(android_log_level, "MACE", ss.str().c_str());
-
-  // Also log to stderr (for standalone Android apps).
-  std::cerr << "IWEF"[severity_] << " " << ss.str() << std::endl;
-#else
-  fprintf(stderr, "%c %s:%d] %s\n", "IWEF"[severity_], fname_, line_,
-          str().c_str());
-#endif
-
-  // When there is a fatal log, terminate execution
-  if (severity_ == FATAL) {
-    DealWithFatal();
-  }
-}
-namespace {
-
-int LogLevelStrToInt(const char *mace_env_var_val) {
-  if (mace_env_var_val == nullptr) {
-    return 0;
-  }
-  // Simply use atoi here. Return 0 if convert unsuccessfully.
-  return atoi(mace_env_var_val);
-}
-
-int MinLogLevelFromEnv() {
-  // Read the min log level from env once during the first call to logging.
-  static int log_level = LogLevelStrToInt(getenv("MACE_CPP_MIN_LOG_LEVEL"));
-  return log_level;
-}
-
-int MinVLogLevelFromEnv() {
-  // Read the min vlog level from env once during the first call to logging.
-  static int vlog_level = LogLevelStrToInt(getenv("MACE_CPP_MIN_VLOG_LEVEL"));
-  return vlog_level;
-}
-
-}  // namespace
-
-LogMessage::~LogMessage() {
-  int min_log_level = MinLogLevelFromEnv();
-  if (severity_ >= min_log_level) GenerateLogMessage();
-}
-
-int LogMessage::MinVLogLevel() {
-  return MinVLogLevelFromEnv();
-}
-
-}  // namespace logging
-}  // namespace mace
diff --git a/mace/utils/logging.h b/mace/utils/logging.h
index 63d372d88b5c1241e34f8c92c7ff9b7c41d6a33e..8a5f2f8e025f1ad350a9503243dd66ad9628691f 100644
--- a/mace/utils/logging.h
+++ b/mace/utils/logging.h
@@ -1,4 +1,4 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
+// Copyright 2019 The MACE Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -21,45 +21,19 @@
 #include <vector>
 #include <utility>
 
-#include "mace/public/mace.h"
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
+#include "mace/port/logger.h"
+#include "mace/utils/macros.h"
 #include "mace/utils/string_util.h"
-#include "mace/utils/utils.h"
 
-#undef ERROR
 
 namespace mace {
-
-// Log severity level constants.
-const int INFO = 0;
-const int WARNING = 1;
-const int ERROR = 2;
-const int FATAL = 3;
-
-namespace logging {
-
-class LogMessage : public std::ostringstream {
- public:
-  LogMessage(const char *fname, int line, int severity);
-  ~LogMessage();
-
-  static int MinVLogLevel();
-
- private:
-  void GenerateLogMessage();
-  void DealWithFatal();
-
-  const char *fname_;
-  int line_;
-  int severity_;
-};
+namespace logging_internal {
 
 #define LOG(severity) \
-  ::mace::logging::LogMessage(__FILE__, __LINE__, mace::severity)
+  ::mace::port::Logger(__FILE__, __LINE__, mace::severity)
 
-// Set MACE_CPP_MIN_VLOG_LEVEL environment to update minimum log level of VLOG.
-// Only when vlog_level <= MinVLogLevel(), it will produce output.
-#define VLOG_IS_ON(vll) ((vll) <= ::mace::logging::LogMessage::MinVLogLevel())
+#define VLOG_IS_ON(vll) (mace::ShouldGenerateVLogMessage(vll))
 #define VLOG(vll) if (VLOG_IS_ON(vll)) LOG(INFO)
 
 // MACE_CHECK/MACE_ASSERT dies with a fatal error if condition is not true.
@@ -85,17 +59,27 @@ class LogMessage : public std::ostringstream {
 template <typename T>
 T &&CheckNotNull(const char *file, int line, const char *exprtext, T &&t) {
   if (t == nullptr) {
-    ::mace::logging::LogMessage(file, line, FATAL) << std::string(exprtext);
+    ::mace::port::Logger(file, line, FATAL) << std::string(exprtext);
   }
   return std::forward<T>(t);
 }
 
 #define MACE_CHECK_NOTNULL(val) \
-  ::mace::logging::CheckNotNull(__FILE__, __LINE__, \
-                                "'" #val "' Must not be NULL", (val))
+  ::mace::logging_internal::CheckNotNull(__FILE__, __LINE__, \
+                                         "'" #val "' Must not be NULL", (val))
 
 #define MACE_NOT_IMPLEMENTED MACE_CHECK(false, "not implemented")
 
+#define MACE_RETURN_IF_ERROR(stmt)                           \
+  {                                                          \
+    MaceStatus status = (stmt);                              \
+    if (status != MaceStatus::MACE_SUCCESS) {                \
+      VLOG(0) << #stmt << " failed with error: "             \
+              << status.information();                       \
+      return status;                                         \
+    }                                                        \
+  }
+
 class LatencyLogger {
  public:
   LatencyLogger(int vlog_level, const std::string &message)
@@ -121,11 +105,21 @@ class LatencyLogger {
   MACE_DISABLE_COPY_AND_ASSIGN(LatencyLogger);
 };
 
-#define MACE_LATENCY_LOGGER(vlog_level, ...)              \
-  mace::logging::LatencyLogger latency_logger_##__line__( \
+#define MACE_LATENCY_LOGGER(vlog_level, ...)                                  \
+  mace::logging_internal::LatencyLogger latency_logger_##__line__(            \
       vlog_level, VLOG_IS_ON(vlog_level) ? mace::MakeString(__VA_ARGS__) : "")
 
-}  // namespace logging
+
+#ifdef MACE_ENABLE_MALLOC_LOGGING
+#define MACE_MEMORY_LOGGING_GUARD()                                      \
+  auto malloc_logger_##__line__ = port::Env::Default()->NewMallocLogger( \
+      ::mace::port::Logger(__FILE__, __LINE__, mace::INFO), \
+      std::string(__FILE__) + ":" + std::string(__func__));
+#else
+#define MACE_MEMORY_LOGGING_GUARD()
+#endif
+
+}  // namespace logging_internal
 }  // namespace mace
 
 #endif  // MACE_UTILS_LOGGING_H_
diff --git a/mace/utils/logging_test.cc b/mace/utils/logging_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..88cee53dbebcb35cfabb12918565ea290cbd46c0
--- /dev/null
+++ b/mace/utils/logging_test.cc
@@ -0,0 +1,43 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/utils/logging.h"
+
+#include <gtest/gtest.h>
+
+namespace mace {
+namespace {
+
+class LoggingTest : public ::testing::Test {
+};
+
+TEST_F(LoggingTest, Basic) {
+  LOG(INFO) << "info logging";
+  LOG(WARNING) << "warning logging";
+  LOG(ERROR) << "error logging";
+
+  VLOG(1) << "vlog 1 logging";
+  VLOG(2) << "vlog 2 logging";
+
+  if (VLOG_IS_ON(1)) {
+    VLOG(1) << "vlog 1 logging";
+  }
+}
+
+TEST_F(LoggingTest, LogFatal) {
+  EXPECT_DEATH(do { LOG(FATAL) << "fatal logging"; } while (false), "");
+}
+
+}  // namespace
+}  // namespace mace
diff --git a/mace/core/macros.h b/mace/utils/macros.h
similarity index 61%
rename from mace/core/macros.h
rename to mace/utils/macros.h
index e90049f4764ea07654ed810e8086230dc2fc9b5b..1ce38183018b5ddb9b64a3756126cfd6426c4f68 100644
--- a/mace/core/macros.h
+++ b/mace/utils/macros.h
@@ -1,4 +1,4 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
+// Copyright 2019 The MACE Authors. All Rights Reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -12,8 +12,27 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef MACE_CORE_MACROS_H_
-#define MACE_CORE_MACROS_H_
+#ifndef MACE_UTILS_MACROS_H_
+#define MACE_UTILS_MACROS_H_
+
+namespace mace {
+
+// Disable the copy and assignment operator for a class.
+#ifndef MACE_DISABLE_COPY_AND_ASSIGN
+#define MACE_DISABLE_COPY_AND_ASSIGN(CLASSNAME)     \
+  CLASSNAME(const CLASSNAME &) = delete;            \
+  CLASSNAME &operator=(const CLASSNAME &) = delete;
+#endif
+
+#ifndef MACE_EMPTY_VIRTUAL_DESTRUCTOR
+#define MACE_EMPTY_VIRTUAL_DESTRUCTOR(CLASSNAME) \
+ public:                                         \
+  virtual ~CLASSNAME() {}
+#endif
+
+#define MACE_UNUSED(var) (void)(var)
+
+#define MACE_COMPUTE_KERNEL_SOURCE(...) #__VA_ARGS__
 
 // GCC can be told that a certain branch is not likely to be taken (for
 // instance, a CHECK failure), and use that information in static analysis.
@@ -27,6 +46,6 @@
 #define MACE_PREDICT_TRUE(x) (x)
 #endif
 
-#define MACE_UNUSED(var) (void)(var)
+}  // namespace mace
 
-#endif  // MACE_CORE_MACROS_H_
+#endif  // MACE_UTILS_MACROS_H_
diff --git a/mace/utils/utils.h b/mace/utils/math.h
similarity index 58%
rename from mace/utils/utils.h
rename to mace/utils/math.h
index 7ebdd22126a2e4e1a360a6f012fea9d8fb982d44..0293806c66667d55439b6802e1a8ec3943c1635e 100644
--- a/mace/utils/utils.h
+++ b/mace/utils/math.h
@@ -12,31 +12,17 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-#ifndef MACE_UTILS_UTILS_H_
-#define MACE_UTILS_UTILS_H_
+#ifndef MACE_UTILS_MATH_H_
+#define MACE_UTILS_MATH_H_
 
-#include <algorithm>
-#include <cstdlib>
 #include <cmath>
-#include <map>
-#include <string>
-#include <vector>
 
-namespace mace {
+#include <algorithm>
+#include <vector>
 
-// Disable the copy and assignment operator for a class.
-#ifndef MACE_DISABLE_COPY_AND_ASSIGN
-#define MACE_DISABLE_COPY_AND_ASSIGN(CLASSNAME) \
- private:                                       \
-  CLASSNAME(const CLASSNAME &) = delete;        \
-  CLASSNAME &operator=(const CLASSNAME &) = delete
-#endif
+#include "mace/utils/logging.h"
 
-#ifndef MACE_EMPTY_VIRTUAL_DESTRUCTOR
-#define MACE_EMPTY_VIRTUAL_DESTRUCTOR(CLASSNAME) \
- public:                                         \
-  virtual ~CLASSNAME() {}
-#endif
+namespace mace {
 
 template <typename Integer>
 Integer RoundUp(Integer i, Integer factor) {
@@ -69,8 +55,6 @@ Integer CeilQuotient(Integer a, Integer b) {
   return (a + b - 1) / b;
 }
 
-std::string ObfuscateString(const std::string &src,
-                            const std::string &lookup_table);
 template <typename Integer>
 inline Integer Clamp(Integer in, Integer low, Integer high) {
   return std::max<Integer>(low, std::min<Integer>(in, high));
@@ -98,48 +82,11 @@ inline T ScalarTanh(T in) {
   }
 }
 
-std::string ObfuscateString(const std::string &src);
-
-std::string ObfuscateSymbol(const std::string &src);
-
-#ifdef MACE_OBFUSCATE_LITERALS
-#define MACE_OBFUSCATE_STRING(str) ObfuscateString(str)
-#define MACE_OBFUSCATE_SYMBOL(str) ObfuscateSymbol(str)
-#else
-#define MACE_OBFUSCATE_STRING(str) (str)
-#define MACE_OBFUSCATE_SYMBOL(str) (str)
-#endif
-
-std::vector<std::string> Split(const std::string &str, char delims);
-
-bool ReadBinaryFile(std::vector<unsigned char> *data,
-                    const std::string &filename);
-
-void MemoryMap(const std::string &file,
-               const unsigned char **data,
-               size_t *size);
-
-void MemoryUnMap(const unsigned char *data,
-                 const size_t &size);
-
-template <typename T>
-std::vector<std::string> MapKeys(const std::map<std::string, T> &data) {
-  std::vector<std::string> keys;
-  for (auto &kv : data) {
-    keys.push_back(kv.first);
-  }
-  return keys;
-}
-
-inline bool EnvEnabled(std::string env_name) {
-  char *env = getenv(env_name.c_str());
-  return !(!env || env[0] == 0 || env[0] == '0');
-}
-
 template <typename SrcType, typename DstType>
 std::vector<DstType> TransposeShape(const std::vector<SrcType> &shape,
                                     const std::vector<int> &dst_dims) {
   size_t shape_dims = shape.size();
+  MACE_CHECK(shape_dims == dst_dims.size());
   std::vector<DstType> output_shape(shape_dims);
   for (size_t i = 0; i < shape_dims; ++i) {
     output_shape[i] = static_cast<DstType>(shape[dst_dims[i]]);
@@ -148,4 +95,5 @@ std::vector<DstType> TransposeShape(const std::vector<SrcType> &shape,
 }
 
 }  // namespace mace
-#endif  // MACE_UTILS_UTILS_H_
+
+#endif  // MACE_UTILS_MATH_H_
diff --git a/mace/utils/memory_logging.h b/mace/utils/memory_logging.h
deleted file mode 100644
index 4e3cd5883b749b8f1d49d5f8d6ec886d8f65a78b..0000000000000000000000000000000000000000
--- a/mace/utils/memory_logging.h
+++ /dev/null
@@ -1,112 +0,0 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef MACE_UTILS_MEMORY_LOGGING_H_
-#define MACE_UTILS_MEMORY_LOGGING_H_
-
-#ifndef __hexagon__
-#include <malloc.h>
-#endif
-#include <string>
-
-#include "mace/utils/logging.h"
-
-namespace mace {
-
-#ifdef MACE_ENABLE_MEMORY_LOGGING
-class MallinfoChangeLogger {
- public:
-  explicit MallinfoChangeLogger(const std::string &name) : name_(name) {
-    prev_ = mallinfo();
-  }
-  ~MallinfoChangeLogger() {
-    struct mallinfo curr = mallinfo();
-    LogMallinfoChange(name_, curr, prev_);
-  }
-
- private:
-  const std::string name_;
-  struct mallinfo prev_;
-
-  struct mallinfo LogMallinfoChange(const std::string &name,
-                                    const struct mallinfo curr,
-                                    const struct mallinfo prev) {
-    if (prev.arena != curr.arena) {
-      LOG(INFO) << "[" << name << "] "
-                << "Non-mmapped space allocated (bytes): " << curr.arena
-                << ", diff: " << ((int64_t)curr.arena - (int64_t)prev.arena);
-    }
-    if (prev.ordblks != curr.ordblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Number of free chunks: " << curr.ordblks << ", diff: "
-                << ((int64_t)curr.ordblks - (int64_t)prev.ordblks);
-    }
-    if (prev.smblks != curr.smblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Number of free fastbin blocks: " << curr.smblks
-                << ", diff: " << ((int64_t)curr.smblks - (int64_t)prev.smblks);
-    }
-    if (prev.hblks != curr.hblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Number of mmapped regions: " << curr.hblks
-                << ", diff: " << ((int64_t)curr.hblks - (int64_t)prev.hblks);
-    }
-    if (prev.hblkhd != curr.hblkhd) {
-      LOG(INFO) << "[" << name << "] "
-                << "Space allocated in mmapped regions (bytes): " << curr.hblkhd
-                << ", diff: " << ((int64_t)curr.hblkhd - (int64_t)prev.hblkhd);
-    }
-    if (prev.usmblks != curr.usmblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Maximum total allocated space (bytes): " << curr.usmblks
-                << ", diff: "
-                << ((int64_t)curr.usmblks - (int64_t)prev.usmblks);
-    }
-    if (prev.fsmblks != curr.fsmblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Space in freed fastbin blocks (bytes): " << curr.fsmblks
-                << ", diff: "
-                << ((int64_t)curr.fsmblks - (int64_t)prev.fsmblks);
-    }
-    if (prev.uordblks != curr.uordblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Total allocated space (bytes): " << curr.uordblks
-                << ", diff: "
-                << ((int64_t)curr.uordblks - (int64_t)prev.uordblks);
-    }
-    if (prev.fordblks != curr.fordblks) {
-      LOG(INFO) << "[" << name << "] "
-                << "Total free space (bytes): " << curr.fordblks << ", diff: "
-                << ((int64_t)curr.fordblks - (int64_t)prev.fordblks);
-    }
-    if (prev.keepcost != curr.keepcost) {
-      LOG(INFO) << "[" << name << "] "
-                << "Top-most, releasable space (bytes): " << curr.keepcost
-                << ", diff: "
-                << ((int64_t)curr.keepcost - (int64_t)prev.keepcost);
-    }
-    return curr;
-  }
-};
-
-#define MACE_MEMORY_LOGGING_GUARD()                                        \
-  MallinfoChangeLogger mem_logger_##__line__(std::string(__FILE__) + ":" + \
-                                             std::string(__func__));
-#else
-#define MACE_MEMORY_LOGGING_GUARD()
-#endif
-
-}  // namespace mace
-
-#endif  // MACE_UTILS_MEMORY_LOGGING_H_
diff --git a/mace/utils/rwlock.h b/mace/utils/rwlock.h
index c15fa5ad7a605ce1dc0d7b2fabb083a4aba53e7f..b4d6392ce3772fac468b46f450faa89839c8e5f6 100644
--- a/mace/utils/rwlock.h
+++ b/mace/utils/rwlock.h
@@ -17,7 +17,9 @@
 
 #include <condition_variable>  // NOLINT(build/c++11)
 #include <mutex>  // NOLINT(build/c++11)
+
 #include "mace/utils/logging.h"
+#include "mace/utils/macros.h"
 
 namespace mace {
 namespace utils {
@@ -26,10 +28,6 @@ class RWMutex {
  public:
   RWMutex() : counter_(0), waiting_readers_(0), waiting_writers_(0) {}
   ~RWMutex() = default;
-  RWMutex(const RWMutex &) = delete;
-  RWMutex(RWMutex &&) = delete;
-  RWMutex& operator=(const RWMutex &) = delete;
-  RWMutex& operator=(RWMutex &&) = delete;
 
   int counter_;  // -1 for writer, 0 for nobody, 1~n for reader
   int waiting_readers_;
@@ -37,6 +35,8 @@ class RWMutex {
   std::mutex mutex_;
   std::condition_variable reader_cv_;
   std::condition_variable writer_cv_;
+
+  MACE_DISABLE_COPY_AND_ASSIGN(RWMutex);
 };
 
 // Writer first
@@ -61,13 +61,11 @@ class ReadLock {
       }
     }
   }
-  ReadLock(const ReadLock &) = delete;
-  ReadLock(ReadLock &&) = delete;
-  ReadLock& operator=(const ReadLock &) = delete;
-  ReadLock& operator=(ReadLock &&) = delete;
 
  private:
   RWMutex *rw_mutex_;
+
+  MACE_DISABLE_COPY_AND_ASSIGN(ReadLock);
 };
 
 class WriteLock {
@@ -91,13 +89,11 @@ class WriteLock {
       rw_mutex_->reader_cv_.notify_all();
     }
   }
-  WriteLock(const WriteLock &) = delete;
-  WriteLock(WriteLock &&) = delete;
-  WriteLock& operator=(const WriteLock &) = delete;
-  WriteLock& operator=(WriteLock &&) = delete;
 
  private:
   RWMutex *rw_mutex_;
+
+  MACE_DISABLE_COPY_AND_ASSIGN(WriteLock);
 };
 
 }  // namespace utils
diff --git a/mace/utils/stl_util.h b/mace/utils/stl_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..44dd1d8e384b7bfa260e12b9f33183a5ec5b7157
--- /dev/null
+++ b/mace/utils/stl_util.h
@@ -0,0 +1,37 @@
+// Copyright 2018 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef MACE_UTILS_STL_UTIL_H_
+#define MACE_UTILS_STL_UTIL_H_
+
+#include <algorithm>
+#include <cstdlib>
+#include <map>
+#include <string>
+#include <vector>
+
+namespace mace {
+
+template <typename T>
+std::vector<std::string> MapKeys(const std::map<std::string, T> &data) {
+  std::vector<std::string> keys;
+  for (auto &kv : data) {
+    keys.push_back(kv.first);
+  }
+  return keys;
+}
+
+}  // namespace mace
+
+#endif  // MACE_UTILS_STL_UTIL_H_
diff --git a/mace/utils/string_util.cc b/mace/utils/string_util.cc
index 3492706fe068f3caef8ce9443b505f887fb97ab6..8114e3aad7364c20a2d14b75912d1d798df24263 100644
--- a/mace/utils/string_util.cc
+++ b/mace/utils/string_util.cc
@@ -83,4 +83,65 @@ std::string StringFormatter::Table(
 }
 
 }  // namespace string_util
+
+std::string ObfuscateString(const std::string &src,
+                            const std::string &lookup_table) {
+  std::string dest;
+  dest.resize(src.size());
+  for (size_t i = 0; i < src.size(); i++) {
+    dest[i] = src[i] ^ lookup_table[i % lookup_table.size()];
+  }
+  return dest;
+}
+
+// ObfuscateString(ObfuscateString(str)) ==> str
+std::string ObfuscateString(const std::string &src) {
+  // Keep consistent with obfuscation in python tools
+  return ObfuscateString(src, "Mobile-AI-Compute-Engine");
+}
+
+// Obfuscate synbol or path string
+std::string ObfuscateSymbol(const std::string &src) {
+  std::string dest = src;
+  if (dest.empty()) {
+    return dest;
+  }
+  dest[0] = src[0];  // avoid invalid symbol which starts from 0-9
+  const std::string encode_dict =
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_";
+  for (size_t i = 1; i < src.size(); i++) {
+    char ch = src[i];
+    int idx;
+    if (ch >= '0' && ch <= '9') {
+      idx = ch - '0';
+    } else if (ch >= 'a' && ch <= 'z') {
+      idx = 10 + ch - 'a';
+    } else if (ch >= 'A' && ch <= 'Z') {
+      idx = 10 + 26 + ch - 'a';
+    } else if (ch == '_') {
+      idx = 10 + 26 + 26;
+    } else {
+      dest[i] = ch;
+      continue;
+    }
+    // There is no collision if it's true for every char at every position
+    dest[i] = encode_dict[(idx + i + 31) % encode_dict.size()];
+  }
+  return dest;
+}
+
+std::vector<std::string> Split(const std::string &str, char delims) {
+  std::vector<std::string> result;
+  std::string tmp = str;
+  while (!tmp.empty()) {
+    size_t next_offset = tmp.find(delims);
+    result.push_back(tmp.substr(0, next_offset));
+    if (next_offset == std::string::npos) {
+      break;
+    } else {
+      tmp = tmp.substr(next_offset + 1);
+    }
+  }
+  return result;
+}
 }  // namespace mace
diff --git a/mace/utils/string_util.h b/mace/utils/string_util.h
index c41aaaa12fdb682bc7aea2d08076b867ad8615f0..c9df13566335b4041aca30d6a6f4e911434bb0d4 100644
--- a/mace/utils/string_util.h
+++ b/mace/utils/string_util.h
@@ -15,6 +15,7 @@
 #ifndef MACE_UTILS_STRING_UTIL_H_
 #define MACE_UTILS_STRING_UTIL_H_
 
+#include <algorithm>
 #include <sstream>
 #include <string>
 #include <vector>
@@ -80,6 +81,35 @@ inline std::string MakeString(const std::string &str) {
 
 inline std::string MakeString(const char *c_str) { return std::string(c_str); }
 
+inline std::string ToLower(const std::string &src) {
+  std::string dest(src);
+  std::transform(src.begin(), src.end(), dest.begin(), ::tolower);
+  return dest;
+}
+
+inline std::string ToUpper(const std::string &src) {
+  std::string dest(src);
+  std::transform(src.begin(), src.end(), dest.begin(), ::toupper);
+  return dest;
+}
+
+std::string ObfuscateString(const std::string &src,
+                            const std::string &lookup_table);
+
+std::string ObfuscateString(const std::string &src);
+
+std::string ObfuscateSymbol(const std::string &src);
+
+#ifdef MACE_OBFUSCATE_LITERALS
+#define MACE_OBFUSCATE_STRING(str) ObfuscateString(str)
+#define MACE_OBFUSCATE_SYMBOL(str) ObfuscateSymbol(str)
+#else
+#define MACE_OBFUSCATE_STRING(str) (str)
+#define MACE_OBFUSCATE_SYMBOL(str) (str)
+#endif
+
+std::vector<std::string> Split(const std::string &str, char delims);
+
 }  // namespace mace
 
 #endif  // MACE_UTILS_STRING_UTIL_H_
diff --git a/mace/utils/string_util_test.cc b/mace/utils/string_util_test.cc
new file mode 100644
index 0000000000000000000000000000000000000000..84b9b0a671a5655d3f9660e859d5ff0ed56b9f3a
--- /dev/null
+++ b/mace/utils/string_util_test.cc
@@ -0,0 +1,40 @@
+// Copyright 2019 The MACE Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "mace/utils/string_util.h"
+
+#include <gtest/gtest.h>
+
+namespace mace {
+namespace {
+
+class StringUtilTest : public ::testing::Test {
+};
+
+TEST_F(StringUtilTest, MakeString) {
+  EXPECT_EQ("Hello 2019", MakeString("Hello", " ", 2019));
+}
+
+TEST_F(StringUtilTest, ToLower) {
+  EXPECT_EQ("", ToLower(""));
+  EXPECT_EQ("hello world!", ToLower("Hello World!"));
+}
+
+TEST_F(StringUtilTest, ToUpper) {
+  EXPECT_EQ("", ToLower(""));
+  EXPECT_EQ("HELLO WORLD!", ToUpper("Hello World!"));
+}
+
+}  // namespace
+}  // namespace mace
diff --git a/mace/utils/timer.h b/mace/utils/timer.h
index 3f0e96f4c37045ecd7c9b9a274a6fbf7dc0a0380..0955af7ba5ce5db65e4493b486e028683f5d1e66 100644
--- a/mace/utils/timer.h
+++ b/mace/utils/timer.h
@@ -15,7 +15,7 @@
 #ifndef MACE_UTILS_TIMER_H_
 #define MACE_UTILS_TIMER_H_
 
-#include "mace/utils/env_time.h"
+#include "mace/port/env.h"
 #include "mace/utils/logging.h"
 
 namespace mace {
diff --git a/mace/utils/tuner.h b/mace/utils/tuner.h
index 7ac8467bce6cf4df2c3c6c4741cf6b630497074d..0a33523ce516553187371949ef944b4217ab2661 100644
--- a/mace/utils/tuner.h
+++ b/mace/utils/tuner.h
@@ -14,12 +14,14 @@
 
 #ifndef MACE_UTILS_TUNER_H_
 #define MACE_UTILS_TUNER_H_
+
+// TODO(heliangliang) Fix portability
 #include <fcntl.h>
-#include <stdlib.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <unistd.h>
 
+#include <cstdlib>
 #include <cstring>
 #include <fstream>
 #include <functional>
@@ -30,8 +32,8 @@
 #include <vector>
 
 #include "mace/utils/logging.h"
+#include "mace/utils/string_util.h"
 #include "mace/utils/timer.h"
-#include "mace/utils/utils.h"
 
 namespace mace {
 
@@ -293,4 +295,5 @@ class Tuner {
 };
 
 }  // namespace mace
+
 #endif  // MACE_UTILS_TUNER_H_
diff --git a/mace/utils/utils.cc b/mace/utils/utils.cc
deleted file mode 100644
index 10bbac8267997815378ebb2c63f4142ff6d51819..0000000000000000000000000000000000000000
--- a/mace/utils/utils.cc
+++ /dev/null
@@ -1,152 +0,0 @@
-// Copyright 2018 The MACE Authors. All Rights Reserved.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#include "mace/utils/utils.h"
-
-#include <fcntl.h>
-#include <sys/mman.h>
-#include <sys/stat.h>
-#include <unistd.h>
-#include <cerrno>
-#include <cstring>
-#include <fstream>
-#include <map>
-#include <sstream>
-#include <string>
-#include <utility>
-#include <vector>
-
-#include "mace/utils/logging.h"
-
-namespace mace {
-
-std::string ObfuscateString(const std::string &src,
-                            const std::string &lookup_table) {
-  std::string dest;
-  dest.resize(src.size());
-  for (size_t i = 0; i < src.size(); i++) {
-    dest[i] = src[i] ^ lookup_table[i % lookup_table.size()];
-  }
-  return dest;
-}
-
-// ObfuscateString(ObfuscateString(str)) ==> str
-std::string ObfuscateString(const std::string &src) {
-  // Keep consistent with obfuscation in python tools
-  return ObfuscateString(src, "Mobile-AI-Compute-Engine");
-}
-
-// Obfuscate synbol or path string
-std::string ObfuscateSymbol(const std::string &src) {
-  std::string dest = src;
-  if (dest.empty()) {
-    return dest;
-  }
-  dest[0] = src[0];  // avoid invalid symbol which starts from 0-9
-  const std::string encode_dict =
-      "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789_";
-  for (size_t i = 1; i < src.size(); i++) {
-    char ch = src[i];
-    int idx;
-    if (ch >= '0' && ch <= '9') {
-      idx = ch - '0';
-    } else if (ch >= 'a' && ch <= 'z') {
-      idx = 10 + ch - 'a';
-    } else if (ch >= 'A' && ch <= 'Z') {
-      idx = 10 + 26 + ch - 'a';
-    } else if (ch == '_') {
-      idx = 10 + 26 + 26;
-    } else {
-      dest[i] = ch;
-      continue;
-    }
-    // There is no collision if it's true for every char at every position
-    dest[i] = encode_dict[(idx + i + 31) % encode_dict.size()];
-  }
-  return dest;
-}
-
-std::vector<std::string> Split(const std::string &str, char delims) {
-  std::vector<std::string> result;
-  std::string tmp = str;
-  while (!tmp.empty()) {
-    size_t next_offset = tmp.find(delims);
-    result.push_back(tmp.substr(0, next_offset));
-    if (next_offset == std::string::npos) {
-      break;
-    } else {
-      tmp = tmp.substr(next_offset + 1);
-    }
-  }
-  return result;
-}
-
-bool ReadBinaryFile(std::vector<unsigned char> *data,
-                    const std::string &filename) {
-  std::ifstream ifs(filename, std::ios::in | std::ios::binary);
-  if (!ifs.is_open()) {
-    return false;
-  }
-  ifs.seekg(0, ifs.end);
-  size_t length = ifs.tellg();
-  ifs.seekg(0, ifs.beg);
-
-  data->resize(length);
-  ifs.read(reinterpret_cast<char *>(data->data()), length);
-
-  if (ifs.fail()) {
-    return false;
-  }
-  ifs.close();
-
-  return true;
-}
-
-void MemoryMap(const std::string &file,
-               const unsigned char **data,
-               size_t *size) {
-  int fd = open(file.c_str(), O_RDONLY);
-  MACE_CHECK(fd >= 0,
-             "Failed to open file ", file, ", error code: ", strerror(errno));
-  struct stat st;
-  fstat(fd, &st);
-  *size = static_cast<size_t>(st.st_size);
-  if (*size == 0) {
-    return;
-  }
-
-  *data = static_cast<const unsigned char *>(
-      mmap(nullptr, *size, PROT_READ, MAP_PRIVATE, fd, 0));
-  MACE_CHECK(*data != static_cast<const unsigned char *>(MAP_FAILED),
-             "Failed to map file ", file, ", error code: ", strerror(errno));
-
-  int ret = close(fd);
-  MACE_CHECK(ret == 0,
-             "Failed to close file ", file, ", error code: ", strerror(errno));
-}
-
-void MemoryUnMap(const unsigned char *data,
-                 const size_t &size) {
-  if (size == 0) {
-    return;
-  }
-  MACE_CHECK(data != nullptr, "data is null");
-
-  int ret = munmap(const_cast<unsigned char *>(data), size);
-
-  MACE_CHECK(ret == 0,
-             "Failed to unmap file, error code: ", strerror(errno));
-}
-
-}  // namespace mace
diff --git a/repository/git/BUILD b/repository/git/BUILD.bazel
similarity index 100%
rename from repository/git/BUILD
rename to repository/git/BUILD.bazel
diff --git a/repository/git/BUILD.tpl b/repository/git/BUILD.bazel.tpl
similarity index 100%
rename from repository/git/BUILD.tpl
rename to repository/git/BUILD.bazel.tpl
diff --git a/repository/git/git_configure.bzl b/repository/git/git_configure.bzl
index ca2b8b2d5d9d158554bb32933a2b9a825081a3bd..aa1ea598970b60b4f3a0b8d79d6e35cf282565e9 100644
--- a/repository/git/git_configure.bzl
+++ b/repository/git/git_configure.bzl
@@ -2,10 +2,10 @@
 """
 def _git_version_conf_impl(repository_ctx):
   repository_ctx.template(
-      "BUILD",
-      Label("//repository/git:BUILD.tpl"))
+      "BUILD.bazel",
+      Label("//repository/git:BUILD.bazel.tpl"))
 
-  mace_root_path = str(repository_ctx.path(Label("@mace//:BUILD")))[:-len("BUILD")]
+  mace_root_path = str(repository_ctx.path(Label("@mace//:BUILD.bazel")))[:-len("BUILD.bazel")]
 
   generated_files_path = repository_ctx.path("gen")
 
diff --git a/repository/opencl-kernel/BUILD b/repository/opencl-kernel/BUILD.bazel
similarity index 100%
rename from repository/opencl-kernel/BUILD
rename to repository/opencl-kernel/BUILD.bazel
diff --git a/repository/opencl-kernel/BUILD.tpl b/repository/opencl-kernel/BUILD.bazel.tpl
similarity index 100%
rename from repository/opencl-kernel/BUILD.tpl
rename to repository/opencl-kernel/BUILD.bazel.tpl
diff --git a/repository/opencl-kernel/opencl_kernel_configure.bzl b/repository/opencl-kernel/opencl_kernel_configure.bzl
index 759233fc77cf1e8a59d07a85dded244ad37ff035..63191cda20032c191992ea3624c13c121c585121 100644
--- a/repository/opencl-kernel/opencl_kernel_configure.bzl
+++ b/repository/opencl-kernel/opencl_kernel_configure.bzl
@@ -3,11 +3,11 @@
 
 def _opencl_encrypt_kernel_impl(repository_ctx):
     repository_ctx.template(
-        "BUILD",
-        Label("//repository/opencl-kernel:BUILD.tpl"),
+        "BUILD.bazel",
+        Label("//repository/opencl-kernel:BUILD.bazel.tpl"),
     )
 
-    mace_root_path = str(repository_ctx.path(Label("@mace//:BUILD")))[:-len("BUILD")]
+    mace_root_path = str(repository_ctx.path(Label("@mace//:BUILD.bazel")))[:-len("BUILD.bazel")]
     generated_files_path = repository_ctx.path("gen")
 
     ret = repository_ctx.execute(
diff --git a/third_party/caffe/BUILD b/third_party/caffe/BUILD.bazel
similarity index 100%
rename from third_party/caffe/BUILD
rename to third_party/caffe/BUILD.bazel
diff --git a/third_party/eigen3/BUILD b/third_party/eigen3/BUILD.bazel
similarity index 100%
rename from third_party/eigen3/BUILD
rename to third_party/eigen3/BUILD.bazel
diff --git a/third_party/nnlib/BUILD b/third_party/nnlib/BUILD.bazel
similarity index 100%
rename from third_party/nnlib/BUILD
rename to third_party/nnlib/BUILD.bazel
diff --git a/tools/aarch64_compiler/BUILD b/tools/aarch64_compiler/BUILD.bazel
similarity index 100%
rename from tools/aarch64_compiler/BUILD
rename to tools/aarch64_compiler/BUILD.bazel
diff --git a/tools/aarch64_compiler/linaro_linux_gcc/BUILD b/tools/aarch64_compiler/linaro_linux_gcc/BUILD.bazel
similarity index 100%
rename from tools/aarch64_compiler/linaro_linux_gcc/BUILD
rename to tools/aarch64_compiler/linaro_linux_gcc/BUILD.bazel
diff --git a/tools/arm_compiler/BUILD b/tools/arm_compiler/BUILD.bazel
similarity index 100%
rename from tools/arm_compiler/BUILD
rename to tools/arm_compiler/BUILD.bazel
diff --git a/tools/arm_compiler/linaro_linux_gcc/BUILD b/tools/arm_compiler/linaro_linux_gcc/BUILD.bazel
similarity index 100%
rename from tools/arm_compiler/linaro_linux_gcc/BUILD
rename to tools/arm_compiler/linaro_linux_gcc/BUILD.bazel
diff --git a/tools/bazel.rc b/tools/bazel.rc
index 6ad5d64ac43fc979531d88036626c189218a7b9e..85d7763737feaa50611f4e671f60808aea9e1e07 100644
--- a/tools/bazel.rc
+++ b/tools/bazel.rc
@@ -14,6 +14,9 @@ build --copt=-DGEMMLOWP_USE_OPENMP
 build:symbol_hidden --copt=-fvisibility=hidden
 
 # Usage example: bazel build --config android
+build:android --linkopt=-pie
+build:android --linkopt=-ldl
+build:android --linkopt=-llog
 build:android --distinct_host_configuration=true
 build:android --crosstool_top=//external:android/crosstool
 build:android --host_crosstool_top=@bazel_tools//tools/cpp:toolchain
diff --git a/tools/bazel_adb_run.py b/tools/bazel_adb_run.py
index 37d02b78f993dc4fcb38e9359ba404b4ed89eed5..328620c1f179869e36b4340199a6aefbe85f4466 100644
--- a/tools/bazel_adb_run.py
+++ b/tools/bazel_adb_run.py
@@ -86,7 +86,7 @@ def parse_args():
         type=str,
         default="all",
         help="SoCs (ro.board.platform from getprop) to build, "
-             "comma seperated list or all/random")
+        "comma seperated list or all/random")
     parser.add_argument(
         "--target", type=str, default="//...", help="Bazel target to build")
     parser.add_argument(
@@ -118,8 +118,8 @@ def parse_args():
         '--device_yml',
         type=str,
         default='',
-        help='embedded linux device config yml file'
-    )
+        help='embedded linux device config yml file')
+    parser.add_argument('--vlog_level', type=int, default=0, help='vlog level')
     return parser.parse_known_args()
 
 
@@ -130,10 +130,12 @@ def main(unused_args):
 
     for target_abi in target_abis:
         toolchain = infer_toolchain(target_abi)
-        sh_commands.bazel_build(target, abi=target_abi,
-                                toolchain=toolchain,
-                                enable_neon=FLAGS.enable_neon,
-                                address_sanitizer=FLAGS.address_sanitizer)
+        sh_commands.bazel_build(
+            target,
+            abi=target_abi,
+            toolchain=toolchain,
+            enable_neon=FLAGS.enable_neon,
+            address_sanitizer=FLAGS.address_sanitizer)
         if FLAGS.run_target:
             target_devices = DeviceManager.list_devices(FLAGS.device_yml)
             if FLAGS.target_socs != TargetSOCTag.all and\
@@ -158,12 +160,11 @@ def main(unused_args):
                     bin_name,
                     args=FLAGS.args,
                     opencl_profiling=True,
-                    vlog_level=0,
+                    vlog_level=FLAGS.vlog_level,
                     out_of_range_check=True,
                     address_sanitizer=FLAGS.address_sanitizer,
                     simpleperf=FLAGS.simpleperf)
-                globals()[FLAGS.stdout_processor](stdouts, dev,
-                                                  target_abi)
+                globals()[FLAGS.stdout_processor](stdouts, dev, target_abi)
 
 
 if __name__ == "__main__":