Merge pull request #9578 from typhoonzero/threadpool_for_io

Multi stream thread pool

Author: typhoonzero

paddle/fluid/framework/threadpool.cc

@@ -14,8 +14,12 @@
 
 #include "paddle/fluid/framework/threadpool.h"
 
+#include "gflags/gflags.h"
 #include "paddle/fluid/platform/enforce.h"
 
+DEFINE_int32(io_threadpool_size, 100,
+             "number of threads used for doing IO, default 100");
+
 namespace paddle {
 namespace framework {
 
@@ -91,5 +95,20 @@ void ThreadPool::TaskLoop() {
   }
 }
 
+std::unique_ptr<ThreadPool> ThreadPoolIO::io_threadpool_(nullptr);
+std::once_flag ThreadPoolIO::io_init_flag_;
+
+ThreadPool* ThreadPoolIO::GetInstanceIO() {
+  std::call_once(io_init_flag_, &ThreadPoolIO::InitIO);
+  return io_threadpool_.get();
+}
+
+void ThreadPoolIO::InitIO() {
+  if (io_threadpool_.get() == nullptr) {
+    // TODO(typhoonzero1986): make this configurable
+    io_threadpool_.reset(new ThreadPool(FLAGS_io_threadpool_size));
+  }
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/framework/threadpool.h

@@ -14,12 +14,12 @@ limitations under the License. */
 
 #pragma once
 
-#include <condition_variable>
+#include <condition_variable>  // NOLINT
 #include <functional>
-#include <future>
-#include <mutex>
+#include <future>  // NOLINT
+#include <mutex>   // NOLINT
 #include <queue>
-#include <thread>
+#include <thread>  // NOLINT
 #include <vector>
 #include "glog/logging.h"
 #include "paddle/fluid/platform/enforce.h"
@@ -28,6 +28,22 @@ limitations under the License. */
 namespace paddle {
 namespace framework {
 
+struct ExceptionHandler {
+  mutable std::future<std::unique_ptr<platform::EnforceNotMet>> future_;
+  explicit ExceptionHandler(
+      std::future<std::unique_ptr<platform::EnforceNotMet>>&& f)
+      : future_(std::move(f)) {}
+  void operator()() const {
+    auto ex = this->future_.get();
+    if (ex != nullptr) {
+      LOG(FATAL) << "The exception is thrown inside the thread pool. You "
+                    "should use RunAndGetException to handle the exception.\n"
+                    "The default exception handler is LOG(FATAL)."
+                 << ex->what();
+    }
+  }
+};
+
 // ThreadPool maintains a queue of tasks, and runs them using a fixed
 // number of threads.
 class ThreadPool {
@@ -87,22 +103,6 @@ class ThreadPool {
   void Wait();
 
  private:
-  struct ExceptionHandler {
-    mutable std::future<std::unique_ptr<platform::EnforceNotMet>> future_;
-    explicit ExceptionHandler(
-        std::future<std::unique_ptr<platform::EnforceNotMet>>&& f)
-        : future_(std::move(f)) {}
-    void operator()() const {
-      auto ex = this->future_.get();
-      if (ex != nullptr) {
-        LOG(FATAL) << "The exception is thrown inside the thread pool. You "
-                      "should use RunAndGetException to handle the exception.\n"
-                      "The default exception handler is LOG(FATAL)."
-                   << ex->what();
-      }
-    }
-  };
-
   DISABLE_COPY_AND_ASSIGN(ThreadPool);
 
   // If the task queue is empty and avaialbe is equal to the number of
@@ -135,6 +135,17 @@ class ThreadPool {
   std::condition_variable completed_;
 };
 
+class ThreadPoolIO : ThreadPool {
+ public:
+  static ThreadPool* GetInstanceIO();
+  static void InitIO();
+
+ private:
+  // NOTE: threadpool in base will be inhereted here.
+  static std::unique_ptr<ThreadPool> io_threadpool_;
+  static std::once_flag io_init_flag_;
+};
+
 // 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.
@@ -143,5 +154,10 @@ std::future<void> Async(Callback callback) {
   return ThreadPool::GetInstance()->Run(callback);
 }
 
+template <typename Callback>
+std::future<void> AsyncIO(Callback callback) {
+  return ThreadPoolIO::GetInstanceIO()->Run(callback);
+}
+
 }  // namespace framework
 }  // namespace paddle

paddle/fluid/operators/detail/grpc_client.cc

@@ -35,7 +35,8 @@ bool RPCClient::AsyncSendVariable(const std::string& ep,
   const framework::Scope* p_scope = &scope;
   const auto ch = GetChannel(ep_val);
 
-  framework::Async([var_name_val, p_ctx, ep_val, p_scope, time_out, ch, this] {
+  framework::AsyncIO([var_name_val, p_ctx, ep_val, p_scope, time_out, ch,
+                      this] {
     auto* var = p_scope->FindVar(var_name_val);
 
     ::grpc::ByteBuffer req;
@@ -89,7 +90,8 @@ bool RPCClient::AsyncGetVariable(const std::string& ep,
   const framework::Scope* p_scope = &scope;
   const auto ch = GetChannel(ep_val);
 
-  framework::Async([var_name_val, ep_val, p_scope, p_ctx, time_out, ch, this] {
+  framework::AsyncIO([var_name_val, ep_val, p_scope, p_ctx, time_out, ch,
+                      this] {
     // prepare input
     sendrecv::VariableMessage req;
     req.set_varname(var_name_val);
@@ -132,8 +134,8 @@ bool RPCClient::AsyncPrefetchVariable(const std::string& ep,
   const framework::Scope* p_scope = &scope;
   const auto ch = GetChannel(ep_val);
 
-  framework::Async([in_var_name_val, out_var_name_val, ep_val, p_scope, p_ctx,
-                    time_out, ch, this] {
+  framework::AsyncIO([in_var_name_val, out_var_name_val, ep_val, p_scope, p_ctx,
+                      time_out, ch, this] {
     auto* var = p_scope->FindVar(in_var_name_val);
 
     ::grpc::ByteBuffer req;
@@ -196,7 +198,7 @@ bool RPCClient::Wait() {
   std::vector<std::future<void>> waits(req_count_);
 
   for (int i = 0; i < req_count_; i++) {
-    waits[i] = framework::Async([i, &a, this] { a[i] = Proceed(); });
+    waits[i] = framework::AsyncIO([i, &a, this] { a[i] = Proceed(); });
   }
 
   for (int i = 0; i < req_count_; i++) {

paddle/fluid/operators/detail/grpc_server.cc

@@ -217,10 +217,10 @@ void AsyncGRPCServer::RunSyncUpdate() {
   std::function<void()> prefetch_register =
       std::bind(&AsyncGRPCServer::TryToRegisterNewPrefetchOne, this);
 
+  // TODO(wuyi): Run these "HandleRequest" in thread pool
   t_send_.reset(
       new std::thread(std::bind(&AsyncGRPCServer::HandleRequest, this,
                                 cq_send_.get(), "cq_send", send_register)));
-
   t_get_.reset(
       new std::thread(std::bind(&AsyncGRPCServer::HandleRequest, this,
                                 cq_get_.get(), "cq_get", get_register)));

python/paddle/fluid/tests/book/test_recognize_digits.py

@@ -157,7 +157,6 @@ def train_loop(main_program):
         for ip in pserver_ips.split(","):
             eplist.append(':'.join([ip, port]))
         pserver_endpoints = ",".join(eplist)  # ip:port,ip:port...
-        pserver_endpoints = os.getenv("PSERVERS")
         trainers = int(os.getenv("TRAINERS"))
         current_endpoint = os.getenv("POD_IP") + ":" + port
         trainer_id = int(os.getenv("PADDLE_INIT_TRAINER_ID"))