module sdl.mutex;


/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997, 1998, 1999, 2000, 2001  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@devolution.com
*/

/* Functions to provide thread synchronization primitives

	These are independent of the other SDL routines.
*/

import sdl.types;

extern(C):

/* Synchronization functions which can time out return this value
   if they time out.
*/
const uint SDL_MUTEX_TIMEDOUT	= 1;

/* This is the timeout value which corresponds to never time out */
const uint SDL_MUTEX_MAXWAIT	= 0xFFFFFFFF;


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Mutex functions                                               */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct SDL_mutex { }

/* Create a mutex, initialized unlocked */
SDL_mutex * SDL_CreateMutex();

/* Lock the mutex  (Returns 0, or -1 on error) */
int SDL_LockMutex(SDL_mutex *m) { return SDL_mutexP(m); }
int SDL_mutexP(SDL_mutex *mutex);

/* Unlock the mutex  (Returns 0, or -1 on error) */
int SDL_UnlockMutex(SDL_mutex* m) { return SDL_mutexV(m); }
int SDL_mutexV(SDL_mutex *mutex);

/* Destroy a mutex */
void SDL_DestroyMutex(SDL_mutex *mutex);


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Semaphore functions                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct SDL_sem { }

/* Create a semaphore, initialized with value, returns NULL on failure. */
SDL_sem * SDL_CreateSemaphore(Uint32 initial_value);

/* Destroy a semaphore */
void SDL_DestroySemaphore(SDL_sem *sem);

/* This function suspends the calling thread until the semaphore pointed 
 * to by sem has a positive count. It then atomically decreases the semaphore
 * count.
 */
int SDL_SemWait(SDL_sem *sem);

/* Non-blocking variant of SDL_SemWait(), returns 0 if the wait succeeds,
   SDL_MUTEX_TIMEDOUT if the wait would block, and -1 on error.
*/
int SDL_SemTryWait(SDL_sem *sem);

/* Variant of SDL_SemWait() with a timeout in milliseconds, returns 0 if
   the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in
   the allotted time, and -1 on error.
   On some platforms this function is implemented by looping with a delay
   of 1 ms, and so should be avoided if possible.
*/
int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms);

/* Atomically increases the semaphore's count (not blocking), returns 0,
   or -1 on error.
 */
int SDL_SemPost(SDL_sem *sem);

/* Returns the current count of the semaphore */
Uint32 SDL_SemValue(SDL_sem *sem);


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Condition variable functions                                  */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
struct SDL_cond { }

/* Create a condition variable */
SDL_cond * SDL_CreateCond();

/* Destroy a condition variable */
void SDL_DestroyCond(SDL_cond *cond);

/* Restart one of the threads that are waiting on the condition variable,
   returns 0 or -1 on error.
 */
int SDL_CondSignal(SDL_cond *cond);

/* Restart all threads that are waiting on the condition variable,
   returns 0 or -1 on error.
 */
int SDL_CondBroadcast(SDL_cond *cond);

/* Wait on the condition variable, unlocking the provided mutex.
   The mutex must be locked before entering this function!
   Returns 0 when it is signaled, or -1 on error.
 */
int SDL_CondWait(SDL_cond *cond, SDL_mutex *mut);

/* Waits for at most 'ms' milliseconds, and returns 0 if the condition
   variable is signaled, SDL_MUTEX_TIMEDOUT if the condition is not
   signaled in the allotted time, and -1 on error.
   On some platforms this function is implemented by looping with a delay
   of 1 ms, and so should be avoided if possible.
*/
int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms);

