Expose num_threads

paddle/fluid/framework/parallel_executor.cc

@@ -245,7 +245,7 @@ struct FetchOpHandle : public OpHandle {
 
 class ParallelExecutorPrivate {
  public:
-  explicit ParallelExecutorPrivate(size_t num_threads = 0)
+  explicit ParallelExecutorPrivate(size_t num_threads)
       : pool_(num_threads == 0 ? nullptr : new ThreadPool(num_threads)) {}
 
   std::vector<platform::Place> places_;
@@ -389,11 +389,11 @@ struct NCCLAllReduceOpHandle : public OpHandle {
 };
 
 ParallelExecutor::ParallelExecutor(
-    const std::vector<platform::Place> &places,
+    size_t num_threads, const std::vector<platform::Place> &places,
     const std::unordered_set<std::string> &params,
     const ProgramDesc &startup_program, const ProgramDesc &main_program,
     const std::string &loss_var_name, Scope *scope)
-    : member_(new ParallelExecutorPrivate()) {
+    : member_(new ParallelExecutorPrivate(num_threads)) {
   member_->places_ = places;
   member_->global_scope_ = scope;
   // Step 1. RunStartupProgram and Bcast the params to devs.

paddle/fluid/framework/parallel_executor.h

@@ -35,7 +35,8 @@ class VarHandleBase;
 
 class ParallelExecutor {
  public:
-  explicit ParallelExecutor(const std::vector<platform::Place>& places,
+  explicit ParallelExecutor(size_t num_threads,
+                            const std::vector<platform::Place>& places,
                             const std::unordered_set<std::string>& params,
                             const ProgramDesc& startup_program,
                             const ProgramDesc& main_program,