SDL/src/thread/psp/SDL_sysmutex.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_PSP

/* An implementation of mutexes using semaphores */

#include "SDL_systhread_c.h"

#include <pspthreadman.h>
#include <pspkerror.h>

#define SCE_KERNEL_MUTEX_ATTR_RECURSIVE 0x0200U

struct SDL_mutex
{
    SceLwMutexWorkarea 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) {

        res = sceKernelCreateLwMutex(
            &mutex->lock,
            "SDL mutex",
            SCE_KERNEL_MUTEX_ATTR_RECURSIVE,
            0,
            NULL);

        if (res < 0) {
            SDL_SetError("Error trying to create mutex: %lx", res);
        }
    } else {
        SDL_OutOfMemory();
    }
    return mutex;
}

/* Free the mutex */
void SDL_DestroyMutex(SDL_mutex *mutex)
{
    if (mutex) {
        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_ERROR_OK) {
        return SDL_SetError("Error trying to lock mutex: %lx", 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_ERROR_OK:
        return 0;
        break;
    case SCE_KERNEL_ERROR_WAIT_TIMEOUT:
        return SDL_MUTEX_TIMEDOUT;
        break;
    default:
        return SDL_SetError("Error trying to lock mutex: %lx", 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: %lx", res);
    }

    return 0;
#endif /* SDL_THREADS_DISABLED */
}

#endif /* SDL_THREAD_PSP */

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