folly/wangle/concurrent/GlobalExecutor.cpp

   1 /*
   2  * Copyright 2014 Facebook, Inc.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *   http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17 #include <folly/experimental/Singleton.h>
  18 #include <folly/wangle/concurrent/IOExecutor.h>
  19 #include <folly/wangle/concurrent/IOThreadPoolExecutor.h>
  20
  21 using namespace folly;
  22 using namespace folly::wangle;
  23
  24 namespace {
  25
  26 Singleton<IOThreadPoolExecutor> globalIOThreadPoolSingleton(
  27     "GlobalIOThreadPool",
  28     [](){
  29       return new IOThreadPoolExecutor(
  30           sysconf(_SC_NPROCESSORS_ONLN),
  31           std::make_shared<NamedThreadFactory>("GlobalIOThreadPool"));
  32     });
  33
  34 }
  35
  36 namespace folly { namespace wangle {
  37
  38 IOExecutor* getIOExecutor() {
  39   auto singleton = IOExecutor::getSingleton();
  40   auto executor = singleton->load();
  41   while (!executor) {
  42     IOExecutor* nullIOExecutor = nullptr;
  43     singleton->compare_exchange_strong(
  44         nullIOExecutor,
  45         Singleton<IOThreadPoolExecutor>::get("GlobalIOThreadPool"));
  46     executor = singleton->load();
  47   }
  48   return executor;
  49 }
  50
  51 void setIOExecutor(IOExecutor* executor) {
  52   IOExecutor::getSingleton()->store(executor);
  53 }
  54
  55 }} // folly::wangle