SDL/src/thread/vita/SDL_sysmutex.c
Sam Lantinga d59caffe2c Added support for clang thread-safety analysis
The annotations have been added to SDL_mutex.h and have been made public so applications can enable this for their own code.

Clang assumes that locking and unlocking can't fail, but SDL has the concept of a NULL mutex, so the mutex functions have been changed not to report errors if a mutex hasn't been initialized. We do have mutexes that might be accessed when they are NULL, notably in the event system, so this is an important change.

This commit cleans up a bunch of rare race conditions in the joystick and game controller code so now everything should be completely protected by the joystick lock.

To test this, change the compiler to "clang -Wthread-safety -Werror=thread-safety -DSDL_THREAD_SAFETY_ANALYSIS"
2022-12-14 09:29:19 -08:00

146 lines
3.4 KiB
C

/*
Simple DirectMedia Layer
Copyright (C) 1997-2022 Sam Lantinga <slouken@libsdl.org>
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "../../SDL_internal.h"
#if SDL_THREAD_VITA
#include "SDL_thread.h"
#include "SDL_systhread_c.h"
#include <psp2/kernel/threadmgr.h>
#include <psp2/kernel/error.h>
struct SDL_mutex
{
SceKernelLwMutexWork lock;
};
/* Create a mutex */
SDL_mutex *
SDL_CreateMutex(void)
{
SDL_mutex *mutex = NULL;
SceInt32 res = 0;
/* Allocate mutex memory */
mutex = (SDL_mutex *)SDL_malloc(sizeof(*mutex));
if (mutex != NULL) {
res = sceKernelCreateLwMutex(
&mutex->lock,
"SDL mutex",
SCE_KERNEL_MUTEX_ATTR_RECURSIVE,
0,
NULL);
if (res < 0) {
SDL_SetError("Error trying to create mutex: %x", res);
}
} else {
SDL_OutOfMemory();
}
return mutex;
}
/* Free the mutex */
void SDL_DestroyMutex(SDL_mutex *mutex)
{
if (mutex != NULL) {
sceKernelDeleteLwMutex(&mutex->lock);
SDL_free(mutex);
}
}
/* Lock the mutex */
int SDL_LockMutex(SDL_mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS /* clang doesn't know about NULL mutexes */
{
#if SDL_THREADS_DISABLED
return 0;
#else
SceInt32 res = 0;
if (mutex == NULL) {
return 0;
}
res = sceKernelLockLwMutex(&mutex->lock, 1, NULL);
if (res != SCE_KERNEL_OK) {
return SDL_SetError("Error trying to lock mutex: %x", res);
}
return 0;
#endif /* SDL_THREADS_DISABLED */
}
/* Try to lock the mutex */
int SDL_TryLockMutex(SDL_mutex *mutex)
{
#if SDL_THREADS_DISABLED
return 0;
#else
SceInt32 res = 0;
if (mutex == NULL) {
return 0;
}
res = sceKernelTryLockLwMutex(&mutex->lock, 1);
switch (res) {
case SCE_KERNEL_OK:
return 0;
break;
case SCE_KERNEL_ERROR_MUTEX_FAILED_TO_OWN:
return SDL_MUTEX_TIMEDOUT;
break;
default:
return SDL_SetError("Error trying to lock mutex: %x", res);
break;
}
return -1;
#endif /* SDL_THREADS_DISABLED */
}
/* Unlock the mutex */
int SDL_UnlockMutex(SDL_mutex *mutex) SDL_NO_THREAD_SAFETY_ANALYSIS /* clang doesn't know about NULL mutexes */
{
#if SDL_THREADS_DISABLED
return 0;
#else
SceInt32 res = 0;
if (mutex == NULL) {
return 0;
}
res = sceKernelUnlockLwMutex(&mutex->lock, 1);
if (res != 0) {
return SDL_SetError("Error trying to unlock mutex: %x", res);
}
return 0;
#endif /* SDL_THREADS_DISABLED */
}
#endif /* SDL_THREAD_VITA */
/* vi: set ts=4 sw=4 expandtab: */