Add a test using the FlatBuffer C API (rather than the FlatBuffer C++ API)

to construct the TFLiteSettings FlatBuffer.

PiperOrigin-RevId: 565184361

tensorflow/lite/core/acceleration/configuration/c/BUILD

@@ -16,19 +16,20 @@
 # C API for delegate plugins.
 
 load("//tensorflow:tensorflow.default.bzl", "get_compatible_with_portable")
+load(
+    "//tensorflow/core/platform:build_config_root.bzl",
+    "tf_gpu_tests_tags",
+)
 load("//tensorflow/lite:build_def.bzl", "tflite_cc_library_with_c_headers_test", "tflite_copts", "tflite_copts_warnings")
-load("//tensorflow/lite/delegates/gpu:build_defs.bzl", "gpu_delegate_linkopts")
-load("//tensorflow/lite/core/c:special_rules.bzl", "experimental_acceleration_api_allowlist")
 load(
     "//tensorflow/lite/core/acceleration/configuration/c:special_rules.bzl",
     "delegate_plugin_visibility_allowlist",
     "gpu_plugin_visibility_allowlist",
     "xnnpack_plugin_visibility_allowlist",
 )
-load(
-    "//tensorflow/core/platform:build_config_root.bzl",
-    "tf_gpu_tests_tags",
-)
+load("//tensorflow/lite/core/c:special_rules.bzl", "experimental_acceleration_api_allowlist")
+load("//tensorflow/lite/core/shims:build_defs.bzl", "build_test")
+load("//tensorflow/lite/delegates/gpu:build_defs.bzl", "gpu_delegate_linkopts")
 
 package(
     # copybara:uncomment default_applicable_licenses = ["//tensorflow:license"],
@@ -173,6 +174,36 @@ cc_test(
     ],
 )
 
+tflite_cc_library_with_c_headers_test(
+    name = "xnnpack_plugin_c_test_lib",
+    testonly = True,
+    srcs = ["xnnpack_plugin_c_test_lib.c"],
+    hdrs = ["xnnpack_plugin_c_test_lib.h"],
+    deps = [
+        ":configuration_c_fbs",
+        ":xnnpack_plugin",
+        "//tensorflow/lite/core/c:common",
+        "//third_party/flatcc:runtime",
+        "@pthreadpool",
+    ],
+)
+
+cc_test(
+    name = "xnnpack_plugin_c_test",
+    srcs = ["xnnpack_plugin_c_test.cc"],
+    deps = [
+        ":configuration_c_fbs",
+        ":xnnpack_plugin",
+        ":xnnpack_plugin_c_test_lib",
+        "//tensorflow/lite/acceleration/configuration:configuration_fbs",
+        "//tensorflow/lite/core/c:common",
+        "//tensorflow/lite/delegates/xnnpack:xnnpack_delegate",
+        "//third_party/flatcc:runtime",
+        "@com_google_googletest//:gtest_main",
+        "@pthreadpool",
+    ],
+)
+
 tflite_cc_library_with_c_headers_test(
     name = "stable_delegate",
     hdrs = ["stable_delegate.h"],
@@ -181,3 +212,44 @@ tflite_cc_library_with_c_headers_test(
         "//tensorflow/lite/core/acceleration/configuration/c:delegate_plugin",
     ],
 )
+
+# This rule invokes the "flatcc" FlatBuffer C API compiler to generate the sources
+# use by the ":configuration_c_fbs" C library rule below.
+genrule(
+    name = "configuration_c_fbs_gen",
+    srcs = ["//tensorflow/lite/acceleration/configuration:configuration.fbs"],
+    outs = [
+        "configuration_builder.h",
+        "configuration_reader.h",
+    ],
+    cmd = "$(location //third_party/flatcc:flatcc) -o$(RULEDIR) --builder --reader $(SRCS)",
+    tools = ["//third_party/flatcc"],
+    # Currently this only enables the API for _building_ configuration flatbuffer objects,
+    # not the APIs for reading them, verifying them, or converting them to/from JSON.
+    # [If you need to enable those, replace the two lines above with the following
+    #   outs = ["configuration_builder.h", "configuration_reader.h", "configuration_verifier.h",
+    #           "configuration_json_parser.h", "configuration_json_printer.h"],
+    #   cmd = "$(location //third_party/flatcc:flatcc) -o$(RULEDIR) " +
+    #         "--builder --reader --verifier --json $(SRCS)",
+    # and then in the rule below -- or preferably in a separate target --
+    # add the additional header files in "hdrs" and fix the dependencies.]
+)
+
+# This rule defines a C library containing the Flatbuffer-generated C API for constructing objects
+# using the FlatBuffer schema generated from tensorflow/lite/acceleration/configuration/configuration.proto,
+# which defines the 'TFLiteSettings' FlatBuffer table and related types.
+tflite_cc_library_with_c_headers_test(
+    name = "configuration_c_fbs",
+    hdrs = [
+        "configuration_builder.h",
+        "configuration_reader.h",
+    ],
+    deps = ["//third_party/flatcc:runtime"],
+)
+
+build_test(
+    name = "configuration_c_fbs_build_test",
+    targets = [
+        ":configuration_c_fbs",
+    ],
+)

tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin_c_test.cc

+/* Copyright 2021 The TensorFlow 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.
+==============================================================================*/
+
+// Some simple unit tests of the C API Delegate Plugin for the
+// XNNPACK Delegate, implemented using the FlatBuffers C API
+// to construct the TFLiteSettings FlatBuffer.
+
+#include <gtest/gtest.h>
+#include "pthreadpool.h"  // from @pthreadpool
+#include "tensorflow/lite/acceleration/configuration/configuration_generated.h"
+#include "tensorflow/lite/core/acceleration/configuration/c/configuration_reader.h"
+#include "tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin.h"
+#include "tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin_c_test_lib.h"
+#include "tensorflow/lite/core/c/common.h"
+#include "tensorflow/lite/delegates/xnnpack/xnnpack_delegate.h"
+
+namespace tflite {
+
+class XnnpackTest : public testing::Test {
+ public:
+  static constexpr int kNumThreadsForTest = 7;
+  void SetUp() override {
+    // Construct a FlatBuffer that contains
+    // TFLiteSettings { XNNPackSettings { num_threads: kNumThreadsForTest } }.
+    settings_storage_ =
+        SettingsStorageCreateWithXnnpackThreads(kNumThreadsForTest);
+    settings_ = SettingsStorageGetSettings(settings_storage_);
+  }
+  void TearDown() override {
+    SettingsStorageDestroy(settings_storage_);
+    settings_ = nullptr;
+  }
+  ~XnnpackTest() override = default;
+
+ protected:
+  SettingsStorage *settings_storage_;
+  const void
+      *settings_;  // settings_ points into storage owned by settings_storage_.
+};
+
+constexpr int XnnpackTest::kNumThreadsForTest;
+
+TEST_F(XnnpackTest, CanCreateAndDestroyDelegate) {
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  EXPECT_NE(delegate, nullptr);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+TEST_F(XnnpackTest, CanGetDelegateErrno) {
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  int error_number =
+      TfLiteXnnpackDelegatePluginCApi()->get_delegate_errno(delegate);
+  EXPECT_EQ(error_number, 0);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+TEST_F(XnnpackTest, SetsCorrectThreadCount) {
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  pthreadpool_t threadpool =
+      static_cast<pthreadpool_t>(TfLiteXNNPackDelegateGetThreadPool(delegate));
+  int thread_count = pthreadpool_get_threads_count(threadpool);
+  EXPECT_EQ(thread_count, kNumThreadsForTest);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+TEST_F(XnnpackTest, UsesDefaultFlagsByDefault) {
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  int flags = TfLiteXNNPackDelegateGetFlags(delegate);
+  EXPECT_EQ(flags, TfLiteXNNPackDelegateOptionsDefault().flags);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+TEST_F(XnnpackTest, UsesSpecifiedFlagsWhenNonzero) {
+  SettingsStorageDestroy(settings_storage_);
+  settings_storage_ = SettingsStorageCreateWithXnnpackFlags(
+      tflite_XNNPackFlags_TFLITE_XNNPACK_DELEGATE_FLAG_QU8);
+  settings_ = SettingsStorageGetSettings(settings_storage_);
+
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  int flags = TfLiteXNNPackDelegateGetFlags(delegate);
+  EXPECT_EQ(flags, tflite::XNNPackFlags_TFLITE_XNNPACK_DELEGATE_FLAG_QU8);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+// Settings flags to XNNPackFlags_TFLITE_XNNPACK_DELEGATE_NO_FLAGS (zero)
+// causes flags to be set to their default values, not zero.
+// This is potentially confusing behaviour, but we can't distinguish
+// the case when flags isn't set from the case when flags is set to zero.
+TEST_F(XnnpackTest, UsesDefaultFlagsWhenZero) {
+  SettingsStorageDestroy(settings_storage_);
+  settings_storage_ = SettingsStorageCreateWithXnnpackFlags(
+      tflite_XNNPackFlags_TFLITE_XNNPACK_DELEGATE_NO_FLAGS);
+  settings_ = SettingsStorageGetSettings(settings_storage_);
+
+  TfLiteDelegate *delegate =
+      TfLiteXnnpackDelegatePluginCApi()->create(settings_);
+  int flags = TfLiteXNNPackDelegateGetFlags(delegate);
+  EXPECT_EQ(flags, TfLiteXNNPackDelegateOptionsDefault().flags);
+  TfLiteXnnpackDelegatePluginCApi()->destroy(delegate);
+}
+
+}  // namespace tflite

tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin_c_test_lib.c

+/* Copyright 2021 The TensorFlow 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.
+==============================================================================*/
+
+// Some tests of the XNNPack Plugin using the FlatBuffers C API.
+// This source file is C, not C++, to ensure that we're not accidentally
+// depending on the FlatBuffers C++ API here.
+
+#include "tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin_c_test_lib.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "third_party/flatcc/include/flatcc/flatcc_builder.h"
+#include "tensorflow/lite/core/acceleration/configuration/c/configuration_builder.h"
+#include "tensorflow/lite/core/acceleration/configuration/c/configuration_reader.h"
+
+struct SettingsStorage {
+  // The builder object that allocates the storage.
+  flatcc_builder_t builder;
+
+  // The raw buffer.
+  void* buffer;
+  size_t size;
+
+  // The parsed TFLiteSettings object.
+  const struct tflite_TFLiteSettings_table* tflite_settings;
+};
+typedef struct SettingsStorage SettingsStorage;
+
+SettingsStorage* SettingsStorageCreateWithXnnpackThreads(int num_threads) {
+  struct SettingsStorage* storage =
+      (struct SettingsStorage*) malloc(sizeof(SettingsStorage));
+
+  flatcc_builder_t* builder = &storage->builder;
+  flatcc_builder_init(builder);
+
+  /* Construct a buffer specific to the schema. */
+  tflite_TFLiteSettings_start_as_root(builder);
+  tflite_TFLiteSettings_xnnpack_settings_start(builder);
+  tflite_XNNPackSettings_num_threads_add(builder, num_threads);
+  tflite_TFLiteSettings_xnnpack_settings_end(builder);
+  tflite_TFLiteSettings_end_as_root(builder);
+
+  /* Retrieve buffer - see also `flatcc_builder_get_direct_buffer`. */
+  storage->buffer = flatcc_builder_finalize_buffer(builder, &storage->size);
+
+  /* 'Parse' the buffer. (This is actually just an offset lookup.) */
+  storage->tflite_settings = tflite_TFLiteSettings_as_root(storage->buffer);
+
+  return storage;
+}
+
+SettingsStorage* SettingsStorageCreateWithXnnpackFlags(
+    tflite_XNNPackFlags_enum_t flags) {
+  struct SettingsStorage* storage =
+      (struct SettingsStorage*) malloc(sizeof(SettingsStorage));
+
+  flatcc_builder_t* builder = &storage->builder;
+  flatcc_builder_init(builder);
+
+  /* Construct a buffer specific to the schema. */
+  tflite_TFLiteSettings_start_as_root(builder);
+  tflite_TFLiteSettings_xnnpack_settings_start(builder);
+  tflite_XNNPackSettings_flags_add(builder, flags);
+  tflite_TFLiteSettings_xnnpack_settings_end(builder);
+  tflite_TFLiteSettings_end_as_root(builder);
+
+  /* Retrieve buffer - see also `flatcc_builder_get_direct_buffer`. */
+  storage->buffer = flatcc_builder_finalize_buffer(builder, &storage->size);
+
+  /* 'Parse' the buffer. (This is actually just an offset lookup.) */
+  storage->tflite_settings = tflite_TFLiteSettings_as_root(storage->buffer);
+
+  return storage;
+}
+
+tflite_TFLiteSettings_table_t SettingsStorageGetSettings(
+    const SettingsStorage* storage) {
+  return storage->tflite_settings;
+}
+
+void SettingsStorageDestroy(SettingsStorage* storage) {
+    free(storage->buffer);
+    flatcc_builder_clear(&storage->builder);
+    storage->tflite_settings = NULL;
+    storage->buffer = NULL;
+    storage->size = 0;
+    free(storage);
+}

tensorflow/lite/core/acceleration/configuration/c/xnnpack_plugin_c_test_lib.h

+/* Copyright 2021 The TensorFlow 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.
+==============================================================================*/
+
+// Some library routines for constructing TFLiteSettings FlatBuffers,
+// implemented using the FlatBuffers C API.
+
+#ifndef TENSORFLOW_LITE_CORE_ACCELERATION_CONFIGURATION_C_XNNPACK_PLUGIN_C_TEST_LIB_H_
+#define TENSORFLOW_LITE_CORE_ACCELERATION_CONFIGURATION_C_XNNPACK_PLUGIN_C_TEST_LIB_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "tensorflow/lite/core/acceleration/configuration/c/configuration_reader.h"
+
+// Opaque type for building a TfLiteSettings flatbuffer object.
+typedef struct SettingsStorage SettingsStorage;
+
+// Constructs a TFLiteSettings FlatBuffer with the following contents:
+//
+//     tflite_settings {
+//       xnnpack_settings {
+//         num_threads: <num_threads>
+//       }
+//     }
+struct SettingsStorage* SettingsStorageCreateWithXnnpackThreads(
+    int num_threads);
+
+// Constructs a TFLiteSettings FlatBuffer with the following contents:
+//
+//     tflite_settings {
+//       xnnpack_settings {
+//         flags: <flags>
+//       }
+//     }
+struct SettingsStorage* SettingsStorageCreateWithXnnpackFlags(
+    tflite_XNNPackFlags_enum_t flags);
+
+// Gets the parsed TFLiteSettings FlatBuffer object from the SettingsStorage.
+const struct tflite_TFLiteSettings_table* SettingsStorageGetSettings(
+    const SettingsStorage* storage);
+
+// Deallocates the settings storage allocated by
+// SettingsStorageCreateWithXnnpackThreads or
+// SettingsStorageCreateWithXnnpackFlags.
+void SettingsStorageDestroy(SettingsStorage* storage);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // TENSORFLOW_LITE_CORE_ACCELERATION_CONFIGURATION_C_XNNPACK_PLUGIN_C_TEST_LIB_H_