1 /* 2 * Copyright 2012 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #ifndef SkThreadPool_DEFINED 9 #define SkThreadPool_DEFINED 10 11 #include "SkCondVar.h" 12 #include "SkRunnable.h" 13 #include "SkTDArray.h" 14 #include "SkTInternalLList.h" 15 16 class SkThread; 17 18 class SkThreadPool { 19 20 public: 21 /** 22 * Create a threadpool with count threads, or one thread per core if kThreadPerCore. 23 */ 24 static const int kThreadPerCore = -1; 25 explicit SkThreadPool(int count); 26 ~SkThreadPool(); 27 28 /** 29 * Queues up an SkRunnable to run when a thread is available, or immediately if 30 * count is 0. NULL is a safe no-op. Does not take ownership. 31 */ 32 void add(SkRunnable*); 33 34 /** 35 * Block until all added SkRunnables have completed. Once called, calling add() is undefined. 36 */ 37 void wait(); 38 39 private: 40 struct LinkedRunnable { 41 // Unowned pointer. 42 SkRunnable* fRunnable; 43 44 private: 45 SK_DECLARE_INTERNAL_LLIST_INTERFACE(LinkedRunnable); 46 }; 47 48 enum State { 49 kRunning_State, // Normal case. We've been constructed and no one has called wait(). 50 kWaiting_State, // wait has been called, but there still might be work to do or being done. 51 kHalting_State, // There's no work to do and no thread is busy. All threads can shut down. 52 }; 53 54 SkTInternalLList<LinkedRunnable> fQueue; 55 SkCondVar fReady; 56 SkTDArray<SkThread*> fThreads; 57 State fState; 58 int fBusyThreads; 59 60 static void Loop(void*); // Static because we pass in this. 61 }; 62 63 #endif 64
