NouVeL/ADVect/ext/bgfx/bx/src/mutex.cpp
2022-08-18 12:17:43 -04:00

186 lines
3.4 KiB
C++

/*
* Copyright 2010-2022 Branimir Karadzic. All rights reserved.
* License: https://github.com/bkaradzic/bx/blob/master/LICENSE
*/
#include <bx/mutex.h>
#if BX_CONFIG_SUPPORTS_THREADING
#if BX_CRT_NONE
# include <bx/cpu.h>
# include "crt0.h"
#elif BX_PLATFORM_ANDROID \
|| BX_PLATFORM_BSD \
|| BX_PLATFORM_HAIKU \
|| BX_PLATFORM_LINUX \
|| BX_PLATFORM_IOS \
|| BX_PLATFORM_OSX \
|| BX_PLATFORM_PS4 \
|| BX_PLATFORM_RPI \
|| BX_PLATFORM_NX
# include <pthread.h>
#elif BX_PLATFORM_WINDOWS \
|| BX_PLATFORM_WINRT \
|| BX_PLATFORM_XBOXONE
# ifndef WIN32_LEAN_AND_MEAN
# define WIN32_LEAN_AND_MEAN
# endif // WIN32_LEAN_AND_MEAN
# include <windows.h>
# include <errno.h>
#endif // BX_PLATFORM_
namespace bx
{
#if BX_CRT_NONE
struct State
{
enum Enum
{
Unlocked,
Locked,
Contested,
};
};
Mutex::Mutex()
{
BX_STATIC_ASSERT(sizeof(int32_t) <= sizeof(m_internal) );
uint32_t* futex = (uint32_t*)m_internal;
*futex = State::Unlocked;
}
Mutex::~Mutex()
{
}
void Mutex::lock()
{
uint32_t* futex = (uint32_t*)m_internal;
if (State::Unlocked == atomicCompareAndSwap<uint32_t>(futex, State::Unlocked, State::Locked) )
{
return;
}
while (State::Unlocked != atomicCompareAndSwap<uint32_t>(futex, State::Locked, State::Contested) )
{
crt0::futexWait(futex, State::Contested);
}
}
void Mutex::unlock()
{
uint32_t* futex = (uint32_t*)m_internal;
if (State::Contested == atomicCompareAndSwap<uint32_t>(futex, State::Locked, State::Unlocked) )
{
crt0::futexWake(futex, State::Locked);
}
}
#else
# if BX_PLATFORM_WINDOWS \
|| BX_PLATFORM_XBOXONE \
|| BX_PLATFORM_WINRT
typedef CRITICAL_SECTION pthread_mutex_t;
typedef unsigned pthread_mutexattr_t;
inline int pthread_mutex_lock(pthread_mutex_t* _mutex)
{
EnterCriticalSection(_mutex);
return 0;
}
inline int pthread_mutex_unlock(pthread_mutex_t* _mutex)
{
LeaveCriticalSection(_mutex);
return 0;
}
inline int pthread_mutex_trylock(pthread_mutex_t* _mutex)
{
return TryEnterCriticalSection(_mutex) ? 0 : EBUSY;
}
inline int pthread_mutex_init(pthread_mutex_t* _mutex, pthread_mutexattr_t* /*_attr*/)
{
# if BX_PLATFORM_WINRT
InitializeCriticalSectionEx(_mutex, 4000, 0); // docs recommend 4000 spincount as sane default
# else
InitializeCriticalSection(_mutex);
# endif // BX_PLATFORM_
return 0;
}
inline int pthread_mutex_destroy(pthread_mutex_t* _mutex)
{
DeleteCriticalSection(_mutex);
return 0;
}
# endif // BX_PLATFORM_
Mutex::Mutex()
{
BX_STATIC_ASSERT(sizeof(pthread_mutex_t) <= sizeof(m_internal) );
pthread_mutexattr_t attr;
# if BX_PLATFORM_WINDOWS \
|| BX_PLATFORM_XBOXONE \
|| BX_PLATFORM_WINRT
# else
pthread_mutexattr_init(&attr);
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
# endif // BX_PLATFORM_
pthread_mutex_t* handle = (pthread_mutex_t*)m_internal;
pthread_mutex_init(handle, &attr);
}
Mutex::~Mutex()
{
pthread_mutex_t* handle = (pthread_mutex_t*)m_internal;
pthread_mutex_destroy(handle);
}
void Mutex::lock()
{
pthread_mutex_t* handle = (pthread_mutex_t*)m_internal;
pthread_mutex_lock(handle);
}
void Mutex::unlock()
{
pthread_mutex_t* handle = (pthread_mutex_t*)m_internal;
pthread_mutex_unlock(handle);
}
#endif // BX_CRT_NONE
} // namespace bx
#else
namespace bx
{
Mutex::Mutex()
{
}
Mutex::~Mutex()
{
}
void Mutex::lock()
{
}
void Mutex::unlock()
{
}
} // namespace bx
#endif // BX_CONFIG_SUPPORTS_THREADING