source: trunk/external/sdl-1.2.15/include/SDL_mutex.h @ 2214

Last change on this file since 2214 was 1586, checked in by sam, 9 years ago

build: update Windows SDL binaries to 1.2.15.

File size: 5.7 KB
Line 
1/*
2    SDL - Simple DirectMedia Layer
3    Copyright (C) 1997-2012 Sam Lantinga
4
5    This library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 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    Lesser General Public License for more details.
14
15    You should have received a copy of the GNU Lesser General Public
16    License along with this library; if not, write to the Free Software
17    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18
19    Sam Lantinga
20    slouken@libsdl.org
21*/
22
23#ifndef _SDL_mutex_h
24#define _SDL_mutex_h
25
26/** @file SDL_mutex.h
27 *  Functions to provide thread synchronization primitives
28 *
29 *  @note These are independent of the other SDL routines.
30 */
31
32#include "SDL_stdinc.h"
33#include "SDL_error.h"
34
35#include "begin_code.h"
36/* Set up for C function definitions, even when using C++ */
37#ifdef __cplusplus
38extern "C" {
39#endif
40
41/** Synchronization functions which can time out return this value
42 *  if they time out.
43 */
44#define SDL_MUTEX_TIMEDOUT      1
45
46/** This is the timeout value which corresponds to never time out */
47#define SDL_MUTEX_MAXWAIT       (~(Uint32)0)
48
49
50/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
51/** @name Mutex functions                                        */ /*@{*/
52/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
53
54/** The SDL mutex structure, defined in SDL_mutex.c */
55struct SDL_mutex;
56typedef struct SDL_mutex SDL_mutex;
57
58/** Create a mutex, initialized unlocked */
59extern DECLSPEC SDL_mutex * SDLCALL SDL_CreateMutex(void);
60
61#define SDL_LockMutex(m)        SDL_mutexP(m)
62/** Lock the mutex
63 *  @return 0, or -1 on error
64 */
65extern DECLSPEC int SDLCALL SDL_mutexP(SDL_mutex *mutex);
66
67#define SDL_UnlockMutex(m)      SDL_mutexV(m)
68/** Unlock the mutex
69 *  @return 0, or -1 on error
70 *
71 *  It is an error to unlock a mutex that has not been locked by
72 *  the current thread, and doing so results in undefined behavior.
73 */
74extern DECLSPEC int SDLCALL SDL_mutexV(SDL_mutex *mutex);
75
76/** Destroy a mutex */
77extern DECLSPEC void SDLCALL SDL_DestroyMutex(SDL_mutex *mutex);
78
79/*@}*/
80
81/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
82/** @name Semaphore functions                                    */ /*@{*/
83/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
84
85/** The SDL semaphore structure, defined in SDL_sem.c */
86struct SDL_semaphore;
87typedef struct SDL_semaphore SDL_sem;
88
89/** Create a semaphore, initialized with value, returns NULL on failure. */
90extern DECLSPEC SDL_sem * SDLCALL SDL_CreateSemaphore(Uint32 initial_value);
91
92/** Destroy a semaphore */
93extern DECLSPEC void SDLCALL SDL_DestroySemaphore(SDL_sem *sem);
94
95/**
96 * This function suspends the calling thread until the semaphore pointed
97 * to by sem has a positive count. It then atomically decreases the semaphore
98 * count.
99 */
100extern DECLSPEC int SDLCALL SDL_SemWait(SDL_sem *sem);
101
102/** Non-blocking variant of SDL_SemWait().
103 *  @return 0 if the wait succeeds,
104 *  SDL_MUTEX_TIMEDOUT if the wait would block, and -1 on error.
105 */
106extern DECLSPEC int SDLCALL SDL_SemTryWait(SDL_sem *sem);
107
108/** Variant of SDL_SemWait() with a timeout in milliseconds, returns 0 if
109 *  the wait succeeds, SDL_MUTEX_TIMEDOUT if the wait does not succeed in
110 *  the allotted time, and -1 on error.
111 *
112 *  On some platforms this function is implemented by looping with a delay
113 *  of 1 ms, and so should be avoided if possible.
114 */
115extern DECLSPEC int SDLCALL SDL_SemWaitTimeout(SDL_sem *sem, Uint32 ms);
116
117/** Atomically increases the semaphore's count (not blocking).
118 *  @return 0, or -1 on error.
119 */
120extern DECLSPEC int SDLCALL SDL_SemPost(SDL_sem *sem);
121
122/** Returns the current count of the semaphore */
123extern DECLSPEC Uint32 SDLCALL SDL_SemValue(SDL_sem *sem);
124
125/*@}*/
126
127/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
128/** @name Condition_variable_functions                           */ /*@{*/
129/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
130
131/*@{*/
132/** The SDL condition variable structure, defined in SDL_cond.c */
133struct SDL_cond;
134typedef struct SDL_cond SDL_cond;
135/*@}*/
136
137/** Create a condition variable */
138extern DECLSPEC SDL_cond * SDLCALL SDL_CreateCond(void);
139
140/** Destroy a condition variable */
141extern DECLSPEC void SDLCALL SDL_DestroyCond(SDL_cond *cond);
142
143/** Restart one of the threads that are waiting on the condition variable,
144 *  @return 0 or -1 on error.
145 */
146extern DECLSPEC int SDLCALL SDL_CondSignal(SDL_cond *cond);
147
148/** Restart all threads that are waiting on the condition variable,
149 *  @return 0 or -1 on error.
150 */
151extern DECLSPEC int SDLCALL SDL_CondBroadcast(SDL_cond *cond);
152
153/** Wait on the condition variable, unlocking the provided mutex.
154 *  The mutex must be locked before entering this function!
155 *  The mutex is re-locked once the condition variable is signaled.
156 *  @return 0 when it is signaled, or -1 on error.
157 */
158extern DECLSPEC int SDLCALL SDL_CondWait(SDL_cond *cond, SDL_mutex *mut);
159
160/** Waits for at most 'ms' milliseconds, and returns 0 if the condition
161 *  variable is signaled, SDL_MUTEX_TIMEDOUT if the condition is not
162 *  signaled in the allotted time, and -1 on error.
163 *  On some platforms this function is implemented by looping with a delay
164 *  of 1 ms, and so should be avoided if possible.
165 */
166extern DECLSPEC int SDLCALL SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms);
167
168/*@}*/
169
170/* Ends C function definitions when using C++ */
171#ifdef __cplusplus
172}
173#endif
174#include "close_code.h"
175
176#endif /* _SDL_mutex_h */
177
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