init async ssa executor

paddle/fluid/framework/details/async_ssa_graph_executor.cc

+//   Copyright (c) 2018 PaddlePaddle 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 "paddle/fluid/framework/details/async_ssa_graph_executor.h"
+
+namespace paddle {
+namespace framework {
+namespace details {
+
+AsyncSSAGraphExecutor::AsyncSSAGraphExecutor(
+    const ExecutionStrategy &strategy, const std::vector<Scope *> &local_scopes,
+    const std::vector<platform::Place> &places,
+    std::vector<std::unique_ptr<ir::Graph>> &&graphs)
+    : strategy_(std::move(strategy)),
+      local_scopes_(std::move(local_scopes)),
+      pool_(places.size() >= 2 ? new ::ThreadPool(places.size()) : nullptr),
+      places_(std::move(places)),
+      graphs_(std::move(graphs)) {
+  PADDLE_ENFORCE_EQ(places_.size(), local_scopes_.size());
+
+  // set the correct size of thread pool to each device.
+  strategy_.num_threads_ = strategy_.num_threads_ < places_.size()
+                               ? 1UL
+                               : strategy_.num_threads_ / places_.size();
+  VLOG(1) << "set num_threads: " << strategy_.num_threads_
+          << " to run the operators of the graph on each device.";
+  for (size_t i = 0; i < places.size(); ++i) {
+    executors_.emplace_back(new details::ThreadedSSAGraphExecutor(
+        strategy_, {local_scopes_[i]}, {places_[i]}, std::move(graphs_[i])));
+  }
+}
+
+FeedFetchList AsyncSSAGraphExecutor::Run(
+    const std::vector<std::string> &fetch_tensors) {
+  std::vector<std::future<FeedFetchList>> run_futures;
+
+  std::vector<FeedFetchList> fetch_data;
+  FeedFetchList ret;
+
+  fetch_data.reserve(places_.size());
+  ret.reserve(fetch_tensors.size());
+  exception_holder_.Clear();
+
+  for (size_t i = 0; i < places_.size(); ++i) {
+    auto call = [this, i, &fetch_tensors]() -> FeedFetchList {
+      try {
+        return executors_[i]->Run(fetch_tensors);
+      } catch (...) {
+        exception_holder_.Catch(std::current_exception());
+      }
+      return FeedFetchList();
+    };
+
+    if (pool_) {
+      run_futures.emplace_back(pool_->enqueue(std::move(call)));
+    } else {
+      fetch_data.emplace_back(std::move(call()));
+    }
+  }
+
+  if (pool_) {
+    for (auto &f : run_futures) {
+      if (exception_holder_.IsCaught()) {
+        f.wait();
+      } else {
+        fetch_data.emplace_back(std::move(f.get()));
+      }
+    }
+  }
+  if (exception_holder_.IsCaught()) {
+    exception_holder_.ReThrow();
+  }
+
+  for (size_t fetch_idx = 0; fetch_idx < fetch_tensors.size(); ++fetch_idx) {
+    std::vector<const LoDTensor *> lodtensor_ptrs;
+    lodtensor_ptrs.reserve(local_scopes_.size());
+    for (size_t scope_idx = 0; scope_idx < local_scopes_.size(); ++scope_idx) {
+      lodtensor_ptrs.push_back(&fetch_data.at(scope_idx).at(fetch_idx));
+    }
+    ret.emplace_back();
+    ret.back().MergeLoDTensor(lodtensor_ptrs, platform::CPUPlace());
+  }
+  return ret;
+}
+
+}  // namespace details
+}  // namespace framework
+}  // namespace paddle

paddle/fluid/framework/details/async_ssa_graph_executor.h

+// Copyright (c) 2018 PaddlePaddle 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.
+
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "ThreadPool.h"
+#include "paddle/fluid/framework/details/threaded_ssa_graph_executor.h"
+
+namespace paddle {
+namespace framework {
+namespace details {
+
+class AsyncSSAGraphExecutor : public SSAGraphExecutor {
+ public:
+  AsyncSSAGraphExecutor(const ExecutionStrategy &strategy,
+                        const std::vector<Scope *> &local_scopes,
+                        const std::vector<platform::Place> &places,
+                        std::vector<std::unique_ptr<ir::Graph>> &&graphs);
+  ~AsyncSSAGraphExecutor() final = default;
+  const ir::Graph &Graph() const override { return *graphs_[0]; }
+
+  FeedFetchList Run(const std::vector<std::string> &fetch_tensors) override;
+
+ private:
+  ExecutionStrategy strategy_;
+  std::vector<Scope *> local_scopes_;
+  std::unique_ptr<::ThreadPool> pool_{nullptr};
+  std::vector<platform::Place> places_;
+  std::vector<std::unique_ptr<ir::Graph>> graphs_;
+
+  std::vector<std::unique_ptr<details::ThreadedSSAGraphExecutor>> executors_;
+  ExceptionHolder exception_holder_;
+};
+
+}  // namespace details
+}  // namespace framework
+}  // namespace paddle