Files
dl/third/JoltPhysics/Jolt/Core/Semaphore.cpp
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2026-09-16 14:07:40 +08:00

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// Jolt Physics Library (https://github.com/jrouwe/JoltPhysics)
// SPDX-FileCopyrightText: 2023 Jorrit Rouwe
// SPDX-License-Identifier: MIT
#include <Jolt/Jolt.h>
#include <Jolt/Core/Semaphore.h>
#ifdef JPH_PLATFORM_WINDOWS
JPH_SUPPRESS_WARNING_PUSH
JPH_MSVC_SUPPRESS_WARNING(5039) // winbase.h(13179): warning C5039: 'TpSetCallbackCleanupGroup': pointer or reference to potentially throwing function passed to 'extern "C"' function under -EHc. Undefined behavior may occur if this function throws an exception.
JPH_MSVC2026_PLUS_SUPPRESS_WARNING(4865) // wingdi.h(2806,1): '<unnamed-enum-DISPLAYCONFIG_OUTPUT_TECHNOLOGY_OTHER>': the underlying type will change from 'int' to '__int64' when '/Zc:enumTypes' is specified on the command line
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#ifndef JPH_COMPILER_MINGW
#include <Windows.h>
#else
#include <windows.h>
#endif
JPH_SUPPRESS_WARNING_POP
#endif
JPH_NAMESPACE_BEGIN
Semaphore::Semaphore()
{
#ifdef JPH_PLATFORM_WINDOWS
mSemaphore = CreateSemaphore(nullptr, 0, INT_MAX, nullptr);
if (mSemaphore == nullptr)
{
Trace("Failed to create semaphore");
std::abort();
}
#elif defined(JPH_USE_PTHREADS)
int ret = sem_init(&mSemaphore, 0, 0);
if (ret == -1)
{
Trace("Failed to create semaphore");
std::abort();
}
#elif defined(JPH_USE_GRAND_CENTRAL_DISPATCH)
mSemaphore = dispatch_semaphore_create(0);
if (mSemaphore == nullptr)
{
Trace("Failed to create semaphore");
std::abort();
}
#elif defined(JPH_PLATFORM_BLUE)
if (!JPH_PLATFORM_BLUE_SEMAPHORE_INIT(mSemaphore))
{
Trace("Failed to create semaphore");
std::abort();
}
#endif
}
Semaphore::~Semaphore()
{
#ifdef JPH_PLATFORM_WINDOWS
CloseHandle(mSemaphore);
#elif defined(JPH_USE_PTHREADS)
sem_destroy(&mSemaphore);
#elif defined(JPH_USE_GRAND_CENTRAL_DISPATCH)
dispatch_release(mSemaphore);
#elif defined(JPH_PLATFORM_BLUE)
JPH_PLATFORM_BLUE_SEMAPHORE_DESTROY(mSemaphore);
#endif
}
void Semaphore::Release(uint inNumber)
{
JPH_ASSERT(inNumber > 0);
#if defined(JPH_PLATFORM_WINDOWS) || defined(JPH_USE_PTHREADS) || defined(JPH_USE_GRAND_CENTRAL_DISPATCH) || defined(JPH_PLATFORM_BLUE)
int old_value = mCount.fetch_add(inNumber, std::memory_order_release);
if (old_value < 0)
{
int new_value = old_value + (int)inNumber;
int num_to_release = min(new_value, 0) - old_value;
#ifdef JPH_PLATFORM_WINDOWS
::ReleaseSemaphore(mSemaphore, num_to_release, nullptr);
#elif defined(JPH_USE_PTHREADS)
for (int i = 0; i < num_to_release; ++i)
sem_post(&mSemaphore);
#elif defined(JPH_USE_GRAND_CENTRAL_DISPATCH)
for (int i = 0; i < num_to_release; ++i)
dispatch_semaphore_signal(mSemaphore);
#elif defined(JPH_PLATFORM_BLUE)
JPH_PLATFORM_BLUE_SEMAPHORE_SIGNAL(mSemaphore, num_to_release);
#endif
}
#else
std::lock_guard lock(mLock);
mCount.fetch_add(inNumber, std::memory_order_relaxed);
if (inNumber > 1)
mWaitVariable.notify_all();
else
mWaitVariable.notify_one();
#endif
}
void Semaphore::Acquire(uint inNumber)
{
JPH_ASSERT(inNumber > 0);
#if defined(JPH_PLATFORM_WINDOWS) || defined(JPH_USE_PTHREADS) || defined(JPH_USE_GRAND_CENTRAL_DISPATCH) || defined(JPH_PLATFORM_BLUE)
int old_value = mCount.fetch_sub(inNumber, std::memory_order_acquire);
int new_value = old_value - (int)inNumber;
if (new_value < 0)
{
int num_to_acquire = min(old_value, 0) - new_value;
#ifdef JPH_PLATFORM_WINDOWS
for (int i = 0; i < num_to_acquire; ++i)
WaitForSingleObject(mSemaphore, INFINITE);
#elif defined(JPH_USE_PTHREADS)
for (int i = 0; i < num_to_acquire; ++i)
sem_wait(&mSemaphore);
#elif defined(JPH_USE_GRAND_CENTRAL_DISPATCH)
for (int i = 0; i < num_to_acquire; ++i)
dispatch_semaphore_wait(mSemaphore, DISPATCH_TIME_FOREVER);
#elif defined(JPH_PLATFORM_BLUE)
JPH_PLATFORM_BLUE_SEMAPHORE_WAIT(mSemaphore, num_to_acquire);
#endif
}
#else
std::unique_lock lock(mLock);
mWaitVariable.wait(lock, [this, inNumber]() {
return mCount.load(std::memory_order_relaxed) >= int(inNumber);
});
mCount.fetch_sub(inNumber, std::memory_order_relaxed);
#endif
}
JPH_NAMESPACE_END