api/include/SDL_mutex.h

/*
    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
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id: SDL_mutex.h,v 1.5.2.8 2001/02/17 01:45:30 hercules Exp $";
#endif

#ifndef _SDL_mutex_h
#define _SDL_mutex_h

/* Functions to provide thread synchronization primitives

        These are independent of the other SDL routines.
*/

#include "SDL_main.h"
#include "SDL_types.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

/* Synchronization functions which can time out return this value
   if they time out.
*/
#define SDL_MUTEX_TIMEDOUT      1

/* This is the timeout value which corresponds to never time out */
#define SDL_MUTEX_MAXWAIT       (~(Uint32)0)


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Mutex functions                                               */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/* The SDL mutex structure, defined in SDL_mutex.c */
struct SDL_mutex;
typedef struct SDL_mutex SDL_mutex;

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

/* Lock the mutex  (Returns 0, or -1 on error) */
#define SDL_LockMutex(m)        SDL_mutexP(m)
extern DECLSPEC int SDL_mutexP(SDL_mutex *mutex);

/* Unlock the mutex  (Returns 0, or -1 on error) */
#define SDL_UnlockMutex(m)      SDL_mutexV(m)
extern DECLSPEC int SDL_mutexV(SDL_mutex *mutex);

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


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Semaphore functions                                           */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/* The SDL semaphore structure, defined in SDL_sem.c */
struct SDL_semaphore;
typedef struct SDL_semaphore SDL_sem;

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

/* Destroy a semaphore */
extern DECLSPEC 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.
 */
extern DECLSPEC 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.
*/
extern DECLSPEC 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.
*/
extern DECLSPEC int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms);

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

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


/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
/* Condition variable functions                                  */
/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

/* The SDL condition variable structure, defined in SDL_cond.c */
struct SDL_cond;
typedef struct SDL_cond SDL_cond;

/* Create a condition variable */
extern DECLSPEC SDL_cond * SDL_CreateCond(void);

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

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

/* Restart all threads that are waiting on the condition variable,
   returns 0 or -1 on error.
 */
extern DECLSPEC 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.
 */
extern DECLSPEC 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.
*/
extern DECLSPEC int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms);

/* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_mutex_h */
1	/*
2	SDL - Simple DirectMedia Layer
3	Copyright (C) 1997, 1998, 1999, 2000, 2001 Sam Lantinga
4
5	This library is free software; you can redistribute it and/or
6	modify it under the terms of the GNU Library General Public
7	License as published by the Free Software Foundation; either
8	version 2 of the License, or (at your option) any later version.
9
10	This library is distributed in the hope that it will be useful,
11	but WITHOUT ANY WARRANTY; without even the implied warranty of
12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13	Library General Public License for more details.
14
15	You should have received a copy of the GNU Library General Public
16	License along with this library; if not, write to the Free
17	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18
19	Sam Lantinga
20	slouken@devolution.com
21	*/
22
23	#ifdef SAVE_RCSID
24	static char rcsid =
25	"@(#) $Id: SDL_mutex.h,v 1.5.2.8 2001/02/17 01:45:30 hercules Exp $";
26	#endif
27
28	#ifndef _SDL_mutex_h
29	#define _SDL_mutex_h
30
31	/* Functions to provide thread synchronization primitives
32
33	These are independent of the other SDL routines.
34	*/
35
36	#include "SDL_main.h"
37	#include "SDL_types.h"
38
39	#include "begin_code.h"
40	/* Set up for C function definitions, even when using C++ */
41	#ifdef __cplusplus
42	extern "C" {
43	#endif
44
45	/* Synchronization functions which can time out return this value
46	if they time out.
47	*/
48	#define SDL_MUTEX_TIMEDOUT 1
49
50	/* This is the timeout value which corresponds to never time out */
51	#define SDL_MUTEX_MAXWAIT (~(Uint32)0)
52
53
54	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
55	/* Mutex functions */
56	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
57
58	/* The SDL mutex structure, defined in SDL_mutex.c */
59	struct SDL_mutex;
60	typedef struct SDL_mutex SDL_mutex;
61
62	/* Create a mutex, initialized unlocked */
63	extern DECLSPEC SDL_mutex * SDL_CreateMutex(void);
64
65	/* Lock the mutex (Returns 0, or -1 on error) */
66	#define SDL_LockMutex(m) SDL_mutexP(m)
67	extern DECLSPEC int SDL_mutexP(SDL_mutex *mutex);
68
69	/* Unlock the mutex (Returns 0, or -1 on error) */
70	#define SDL_UnlockMutex(m) SDL_mutexV(m)
71	extern DECLSPEC int SDL_mutexV(SDL_mutex *mutex);
72
73	/* Destroy a mutex */
74	extern DECLSPEC void SDL_DestroyMutex(SDL_mutex *mutex);
75
76
77	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
78	/* Semaphore functions */
79	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
80
81	/* The SDL semaphore structure, defined in SDL_sem.c */
82	struct SDL_semaphore;
83	typedef struct SDL_semaphore SDL_sem;
84
85	/* Create a semaphore, initialized with value, returns NULL on failure. */
86	extern DECLSPEC SDL_sem * SDL_CreateSemaphore(Uint32 initial_value);
87
88	/* Destroy a semaphore */
89	extern DECLSPEC void SDL_DestroySemaphore(SDL_sem *sem);
90
91	/* This function suspends the calling thread until the semaphore pointed
92	* to by sem has a positive count. It then atomically decreases the semaphore
93	* count.
94	*/
95	extern DECLSPEC int SDL_SemWait(SDL_sem *sem);
96
97	/* Non-blocking variant of SDL_SemWait(), returns 0 if the wait succeeds,
98	SDL_MUTEX_TIMEDOUT if the wait would block, and -1 on error.
99	*/
100	extern DECLSPEC int SDL_SemTryWait(SDL_sem *sem);
101
102	/* Variant of SDL_SemWait() with a timeout in milliseconds, returns 0 if
103	the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in
104	the allotted time, and -1 on error.
105	On some platforms this function is implemented by looping with a delay
106	of 1 ms, and so should be avoided if possible.
107	*/
108	extern DECLSPEC int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms);
109
110	/* Atomically increases the semaphore's count (not blocking), returns 0,
111	or -1 on error.
112	*/
113	extern DECLSPEC int SDL_SemPost(SDL_sem *sem);
114
115	/* Returns the current count of the semaphore */
116	extern DECLSPEC Uint32 SDL_SemValue(SDL_sem *sem);
117
118
119	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
120	/* Condition variable functions */
121	/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
122
123	/* The SDL condition variable structure, defined in SDL_cond.c */
124	struct SDL_cond;
125	typedef struct SDL_cond SDL_cond;
126
127	/* Create a condition variable */
128	extern DECLSPEC SDL_cond * SDL_CreateCond(void);
129
130	/* Destroy a condition variable */
131	extern DECLSPEC void SDL_DestroyCond(SDL_cond *cond);
132
133	/* Restart one of the threads that are waiting on the condition variable,
134	returns 0 or -1 on error.
135	*/
136	extern DECLSPEC int SDL_CondSignal(SDL_cond *cond);
137
138	/* Restart all threads that are waiting on the condition variable,
139	returns 0 or -1 on error.
140	*/
141	extern DECLSPEC int SDL_CondBroadcast(SDL_cond *cond);
142
143	/* Wait on the condition variable, unlocking the provided mutex.
144	The mutex must be locked before entering this function!
145	Returns 0 when it is signaled, or -1 on error.
146	*/
147	extern DECLSPEC int SDL_CondWait(SDL_cond cond, SDL_mutex mut);
148
149	/* Waits for at most 'ms' milliseconds, and returns 0 if the condition
150	variable is signaled, SDL_MUTEX_TIMEDOUT if the condition is not
151	signaled in the allotted time, and -1 on error.
152	On some platforms this function is implemented by looping with a delay
153	of 1 ms, and so should be avoided if possible.
154	*/
155	extern DECLSPEC int SDL_CondWaitTimeout(SDL_cond cond, SDL_mutex mutex, Uint32 ms);
156
157	/* Ends C function definitions when using C++ */
158	#ifdef __cplusplus
159	}
160	#endif
161	#include "close_code.h"
162
163	#endif /* _SDL_mutex_h */