Add and use SkSemaphore

src/utils/SkCondVar.cpp

-/*
- * 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_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 true;
-#endif
-}
-
-SkCondVar::SkCondVar() {
-#ifdef SK_BUILD_FOR_WIN32
-    InitializeCriticalSection(&fCriticalSection);
-    SkASSERT(initialize_condition_variable);
-    initialize_condition_variable(&fCondition);
-#else
-    pthread_mutex_init(&fMutex, NULL /* default mutex attr */);
-    pthread_cond_init(&fCond, NULL /* default cond attr */);
-#endif
-}
-
-SkCondVar::~SkCondVar() {
-#ifdef SK_BUILD_FOR_WIN32
-    DeleteCriticalSection(&fCriticalSection);
-    // No need to clean up fCondition.
-#else
-    pthread_mutex_destroy(&fMutex);
-    pthread_cond_destroy(&fCond);
-#endif
-}
-
-void SkCondVar::lock() {
-#ifdef SK_BUILD_FOR_WIN32
-    EnterCriticalSection(&fCriticalSection);
-#else
-    pthread_mutex_lock(&fMutex);
-#endif
-}
-
-void SkCondVar::unlock() {
-#ifdef SK_BUILD_FOR_WIN32
-    LeaveCriticalSection(&fCriticalSection);
-#else
-    pthread_mutex_unlock(&fMutex);
-#endif
-}
-
-void SkCondVar::wait() {
-#ifdef SK_BUILD_FOR_WIN32
-    SkASSERT(sleep_condition_variable);
-    sleep_condition_variable(&fCondition, &fCriticalSection, INFINITE);
-#else
-    pthread_cond_wait(&fCond, &fMutex);
-#endif
-}
-
-void SkCondVar::signal() {
-#ifdef SK_BUILD_FOR_WIN32
-    SkASSERT(wake_condition_variable);
-    wake_condition_variable(&fCondition);
-#else
-    pthread_cond_signal(&fCond);
-#endif
-}
-
-void SkCondVar::broadcast() {
-#ifdef SK_BUILD_FOR_WIN32
-    SkASSERT(wake_all_condition_variable);
-    wake_all_condition_variable(&fCondition);
-#else
-    pthread_cond_broadcast(&fCond);
-#endif
-}