/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#ifndef SkThreadPool_DEFINED
#define SkThreadPool_DEFINED
#include "SkCondVar.h"
#include "SkRunnable.h"
#include "SkTDArray.h"
#include "SkTInternalLList.h"
class SkThread;
class SkThreadPool {
public:
/**
* Create a threadpool with count threads, or one thread per core if kThreadPerCore.
*/
static const int kThreadPerCore = -1;
explicit SkThreadPool(int count);
~SkThreadPool();
/**
* Queues up an SkRunnable to run when a thread is available, or immediately if
* count is 0. NULL is a safe no-op. Does not take ownership.
*/
void add(SkRunnable*);
/**
* Block until all added SkRunnables have completed. Once called, calling add() is undefined.
*/
void wait();
private:
struct LinkedRunnable {
// Unowned pointer.
SkRunnable* fRunnable;
private:
SK_DECLARE_INTERNAL_LLIST_INTERFACE(LinkedRunnable);
};
enum State {
kRunning_State, // Normal case. We've been constructed and no one has called wait().
kWaiting_State, // wait has been called, but there still might be work to do or being done.
kHalting_State, // There's no work to do and no thread is busy. All threads can shut down.
};
SkTInternalLList<LinkedRunnable> fQueue;
SkCondVar fReady;
SkTDArray<SkThread*> fThreads;
State fState;
int fBusyThreads;
static void Loop(void*); // Static because we pass in this.
};
#endif