blob: 15f16e662f70a46bc3c31067c99b80fa44505b5f [file] [log] [blame]
/*
* 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 SkCondVar_DEFINED
#define SkCondVar_DEFINED
#ifdef SK_USE_POSIX_THREADS
#include <pthread.h>
#elif defined(SK_BUILD_FOR_WIN32)
#include <Windows.h>
#endif
/**
* Condition variable for blocking access to shared data from other threads and
* controlling which threads are awake.
*
* Currently only supported on platforms with posix threads and Windows Vista and
* above.
*/
class SkCondVar {
public:
SkCondVar();
~SkCondVar();
/**
* Lock a mutex. Must be done before calling the other functions on this object.
*/
void lock();
/**
* Unlock the mutex.
*/
void unlock();
/**
* Pause the calling thread. Will be awoken when signal() or broadcast() is called.
* Must be called while lock() is held (but gives it up while waiting). Once awoken,
* the calling thread will hold the lock once again.
*/
void wait();
/**
* Wake one thread waiting on this condition. Must be called while lock()
* is held.
*/
void signal();
/**
* Wake all threads waiting on this condition. Must be called while lock()
* is held.
*/
void broadcast();
private:
#ifdef SK_USE_POSIX_THREADS
pthread_mutex_t fMutex;
pthread_cond_t fCond;
#elif defined(SK_BUILD_FOR_WIN32)
CRITICAL_SECTION fCriticalSection;
CONDITION_VARIABLE fCondition;
#endif
};
#endif