1 // Copyright (c) 2013 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Simple thread pool class 6 7 #ifndef LIBRARIES_SDK_UTIL_THREAD_POOL_H_ 8 #define LIBRARIES_SDK_UTIL_THREAD_POOL_H_ 9 10 #include <pthread.h> 11 #include <semaphore.h> 12 13 #include "sdk_util/atomicops.h" 14 15 namespace sdk_util { 16 17 // typdef helper for work function 18 typedef void (*WorkFunction)(int task_index, void* data); 19 20 // ThreadPool is a class to manage num_threads and assign 21 // them num_tasks of work at a time. Each call 22 // to Dispatch(..) will block until all tasks complete. 23 // If 0 is passed in for num_threads, all tasks will be 24 // issued on the dispatch thread. 25 26 class ThreadPool { 27 public: 28 void Dispatch(int num_tasks, WorkFunction work, void* data); 29 explicit ThreadPool(int num_threads); 30 ~ThreadPool(); 31 private: 32 int DecCounter(); 33 void Setup(int counter, WorkFunction work, void* data); 34 void DispatchMany(int num_tasks, WorkFunction work, void* data); 35 void DispatchHere(int num_tasks, WorkFunction work, void* data); 36 void WorkLoop(); 37 static void* WorkerThreadEntry(void* data); 38 void PostExitAndJoinAll(); 39 pthread_t* threads_; 40 Atomic32 counter_; 41 const int num_threads_; 42 bool exiting_; 43 void* user_data_; 44 WorkFunction user_work_function_; 45 sem_t work_sem_; 46 sem_t done_sem_; 47 }; 48 49 } // namespace sdk_util 50 51 #endif // LIBRARIES_SDK_UTIL_THREAD_POOL_H_ 52 53
