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/*
* Copyright 2012 Google Inc.
*
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include "SkCondVar.h"
#if defined(SK_BUILD_FOR_WIN32)
static void (WINAPI *initialize_condition_variable)(PCONDITION_VARIABLE);
static BOOL (WINAPI *sleep_condition_variable)(PCONDITION_VARIABLE, PCRITICAL_SECTION, DWORD);
static void (WINAPI *wake_condition_variable)(PCONDITION_VARIABLE);
static void (WINAPI *wake_all_condition_variable)(PCONDITION_VARIABLE);
template <typename T>
static void set_fn_ptr(T* ptr, FARPROC fn) { *ptr = reinterpret_cast<T>(fn); }
#endif
bool SkCondVar::Supported() {
#ifdef SK_USE_POSIX_THREADS
return true;
#elif defined(SK_BUILD_FOR_WIN32)
// If we're >= Vista we'll find these functions. Otherwise (XP) SkCondVar is not supported.
HMODULE kernel32 = GetModuleHandleA("kernel32.dll");
set_fn_ptr(&initialize_condition_variable,
GetProcAddress(kernel32, "InitializeConditionVariable"));
set_fn_ptr(&sleep_condition_variable,
GetProcAddress(kernel32, "SleepConditionVariableCS"));
set_fn_ptr(&wake_condition_variable,
GetProcAddress(kernel32, "WakeConditionVariable"));
set_fn_ptr(&wake_all_condition_variable,
GetProcAddress(kernel32, "WakeAllConditionVariable"));
return initialize_condition_variable
&& sleep_condition_variable
&& wake_condition_variable
&& wake_all_condition_variable;
#else
return false;
#endif
}
SkCondVar::SkCondVar() {
#ifdef SK_USE_POSIX_THREADS
pthread_mutex_init(&fMutex, NULL /* default mutex attr */);
pthread_cond_init(&fCond, NULL /* default cond attr */);
#elif defined(SK_BUILD_FOR_WIN32)
InitializeCriticalSection(&fCriticalSection);
SkASSERT(initialize_condition_variable);
initialize_condition_variable(&fCondition);
#endif
}
SkCondVar::~SkCondVar() {
#ifdef SK_USE_POSIX_THREADS
pthread_mutex_destroy(&fMutex);
pthread_cond_destroy(&fCond);
#elif defined(SK_BUILD_FOR_WIN32)
DeleteCriticalSection(&fCriticalSection);
// No need to clean up fCondition.
#endif
}
void SkCondVar::lock() {
#ifdef SK_USE_POSIX_THREADS
pthread_mutex_lock(&fMutex);
#elif defined(SK_BUILD_FOR_WIN32)
EnterCriticalSection(&fCriticalSection);
#endif
}
void SkCondVar::unlock() {
#ifdef SK_USE_POSIX_THREADS
pthread_mutex_unlock(&fMutex);
#elif defined(SK_BUILD_FOR_WIN32)
LeaveCriticalSection(&fCriticalSection);
#endif
}
void SkCondVar::wait() {
#ifdef SK_USE_POSIX_THREADS
pthread_cond_wait(&fCond, &fMutex);
#elif defined(SK_BUILD_FOR_WIN32)
SkASSERT(sleep_condition_variable);
sleep_condition_variable(&fCondition, &fCriticalSection, INFINITE);
#endif
}
void SkCondVar::signal() {
#ifdef SK_USE_POSIX_THREADS
pthread_cond_signal(&fCond);
#elif defined(SK_BUILD_FOR_WIN32)
SkASSERT(wake_condition_variable);
wake_condition_variable(&fCondition);
#endif
}
void SkCondVar::broadcast() {
#ifdef SK_USE_POSIX_THREADS
pthread_cond_broadcast(&fCond);
#elif defined(SK_BUILD_FOR_WIN32)
SkASSERT(wake_all_condition_variable);
wake_all_condition_variable(&fCondition);
#endif
}
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