Merge pull request #7196 from reyoung/feature/async_drop_kid

Async to drop kid

paddle/framework/CMakeLists.txt

@@ -26,7 +26,10 @@ nv_test(lod_tensor_gpu_test SRCS lod_tensor_test.cu DEPS lod_tensor)
 
 cc_test(variable_test SRCS variable_test.cc)
 
-cc_library(scope SRCS scope.cc DEPS glog)
+cc_library(threadpool SRCS threadpool.cc)
+cc_test(threadpool_test SRCS threadpool_test.cc DEPS threadpool)
+
+cc_library(scope SRCS scope.cc DEPS glog threadpool)
 cc_test(scope_test SRCS scope_test.cc DEPS scope)
 
 cc_library(data_transform SRCS data_transform.cc DEPS math_function tensor framework_proto)
@@ -70,8 +73,7 @@ cc_test(var_type_inference_test SRCS var_type_inference_test.cc DEPS op_registry
 cc_library(selected_rows SRCS selected_rows.cc DEPS tensor)
 cc_test(selected_rows_test SRCS selected_rows_test.cc DEPS selected_rows)
 
-cc_library(threadpool SRCS threadpool.cc)
-cc_test(threadpool_test SRCS threadpool_test.cc DEPS threadpool)
+
 cc_library(init SRCS init.cc DEPS gflags device_context place stringpiece)
 cc_test(init_test SRCS init_test.cc DEPS init)
 

paddle/framework/scope.cc

@@ -17,6 +17,7 @@ limitations under the License. */
 #include <memory>  // for unique_ptr
 #include <mutex>   // for call_once
 #include "glog/logging.h"
+#include "paddle/framework/threadpool.h"
 #include "paddle/string/printf.h"
 
 namespace paddle {
@@ -87,7 +88,8 @@ void Scope::DeleteScope(Scope* scope) {
   auto it = std::find(this->kids_.begin(), this->kids_.end(), scope);
   PADDLE_ENFORCE(it != this->kids_.end(), "Cannot find %p as kid scope", scope);
   this->kids_.erase(it);
-  delete scope;
+  // Make delete async.
+  Async([scope] { delete scope; });
 }
 
 void Scope::Rename(const std::string& origin_name,

paddle/framework/threadpool.h

@@ -29,7 +29,6 @@ namespace framework {
 class ThreadPool {
  public:
   typedef std::packaged_task<void()> Task;
-  typedef std::function<void()> Fun;
 
   /**
    * @brief   Get a instance of threadpool, the thread number will
@@ -67,7 +66,8 @@ class ThreadPool {
    * @return    std::future<void>, we could wait for the task finished by
    *            f.wait().
    */
-  std::future<void> Run(const Fun& fn) {
+  template <typename Callback>
+  std::future<void> Run(Callback fn) {
     std::unique_lock<std::mutex> lock(mutex_);
     Task task(std::bind(fn));
     std::future<void> f = task.get_future();
@@ -159,5 +159,13 @@ class ThreadPool {
   std::condition_variable completed_;
 };
 
+// Run a function asynchronously.
+// NOTE: The function must return void. If the function need to return a value,
+// you can use lambda to capture a value pointer.
+template <typename Callback>
+std::future<void> Async(Callback callback) {
+  return ThreadPool::GetInstance()->Run(callback);
+}
+
 }  // namespace framework
 }  // namespace paddle