share threadpool of executor in dy2static (#46281)

paddle/fluid/eager/to_static/run_program_op_node.h

@@ -530,16 +530,33 @@ inline void RunProgramGradAPI(
 
     auto &interpretercore_info_cache =
         paddle::framework::InterpreterCoreInfoCache::Instance();
+    std::shared_ptr<paddle::framework::InterpreterCore> interpreter_core =
+        nullptr;
     if (!interpretercore_info_cache.Has(program_id, /*is_grad=*/true)) {
       VLOG(2) << "No interpretercore cahce, so create a new interpretercore";
       details::ShareTensorsIntoScope(out_grad, global_inner_scope);
-      auto interpreter_core =
-          paddle::framework::CreateInterpreterCoreInfoToCache(
-              *backward_program,
-              place,
-              /*is_grad=*/true,
-              program_id,
-              global_inner_scope);
+      interpreter_core = paddle::framework::CreateInterpreterCoreInfoToCache(
+          *backward_program,
+          place,
+          /*is_grad=*/true,
+          program_id,
+          global_inner_scope);
+
+      // share threadpool
+      // NOTE(zhiqiu): this only works interpreter_core is executed strictly
+      // after the related fwd_interpreter_core.
+      PADDLE_ENFORCE_EQ(
+          interpretercore_info_cache.Has(program_id, false),
+          true,
+          paddle::platform::errors::NotFound(
+              "The forward interpretercore of program %d is not found",
+              program_id));
+      auto fwd_interpreter_core =
+          interpretercore_info_cache.GetMutable(program_id, /*is_grad=*/false)
+              .core_;
+      interpreter_core->ShareWorkQueueFrom(fwd_interpreter_core);
+      VLOG(4) << "Share workqueue from " << fwd_interpreter_core.get() << " to "
+              << interpreter_core.get();
 
       // get all eager gc vars
       std::set<std::string> skip_eager_delete_vars;
@@ -552,17 +569,12 @@ inline void RunProgramGradAPI(
       interpretercore_info_cache.UpdateSkipEagerDeleteVars(
           program_id, /*is_grad=*/true, skip_eager_delete_vars);
       VLOG(2) << "Get skip GC vars size is: " << skip_eager_delete_vars.size();
-      if (backward_global_block->OpSize() > 0) {
-        // Debug info: scope info when run end
-        VLOG(3) << paddle::framework::GenScopeTreeDebugInfo(
-            out_scope_vec->front());
-        interpreter_core->Run({});
-      }
     } else {
       VLOG(2) << "Get interpretercore cahce by program:" << program_id;
       auto &cached_value =
           interpretercore_info_cache.GetMutable(program_id, /*is_grad=*/true);
-      auto &interpreter_core = cached_value.core_;
+      interpreter_core = cached_value.core_;
+
       // update scope
       details::ShareTensorsIntoScope(out_grad, global_inner_scope);
       if (interpreter_core->GetVariableScope()->GetMutableScope() !=
@@ -572,14 +584,15 @@ inline void RunProgramGradAPI(
                                    global_inner_scope);
         interpreter_core->reset_scope(global_inner_scope);
       }
+    }
 
-      if (backward_global_block->OpSize() > 0) {
-        // Debug info: scope info when run end
-        VLOG(3) << paddle::framework::GenScopeTreeDebugInfo(
-            out_scope_vec->front());
-        interpreter_core->Run({});
-      }
+    if (backward_global_block->OpSize() > 0) {
+      // Debug info: scope info when run end
+      VLOG(3) << paddle::framework::GenScopeTreeDebugInfo(
+          out_scope_vec->front());
+      interpreter_core->Run({});
     }
+
     // Step 4. get outputs
     details::ShareTensorsFromScopeWithPartialBlock(x_grad,
                                                    *forward_global_block,

paddle/fluid/framework/new_executor/interpretercore.cc

@@ -284,7 +284,7 @@ void InterpreterCore::reset_scope(Scope* new_scope) {
 
 void InterpreterCore::ShareWorkQueueFrom(std::shared_ptr<InterpreterCore> src) {
   async_work_queue_ = src->GetWorkQueue();
-  VLOG(8) << "Share AsyncWorkQueue from InterpreterCore(" << &src
+  VLOG(8) << "Share AsyncWorkQueue from InterpreterCore(" << src.get()
           << ") to InterpreterCore(" << this << ")";
 }