Mercurial > sdl-ios-xcode

annotate src/thread/dc/SDL_syscond.c @ 1861:b42823412c3b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Fixed bug #232 ------- Comment #2 From Matthias Geissert 2006-05-24 07:54 [reply] ------- See http://dri.sourceforge.net/doc/DRIuserguide.html, section 11.5. There is written that you need to use RTLD_GLOBAL, since, otherwise, nested open of dynamic libraries doesn't work. However, This is necassary in this case, since libGL opens the hardware-specific driver/library. I hope this helps you.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 20 Jun 2006 03:52:41 +0000
parents d910939febfa
children 782fd950bd46 c121d94672cb a1b03ba2fcd0
rev   line source
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
1 /*
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
2 SDL - Simple DirectMedia Layer
1312
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
3 Copyright (C) 1997-2006 Sam Lantinga
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
4
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
5 This library is free software; you can redistribute it and/or
1312
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
6 modify it under the terms of the GNU Lesser General Public
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
7 License as published by the Free Software Foundation; either
1312
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
8 version 2.1 of the License, or (at your option) any later version.
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
9
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
10 This library is distributed in the hope that it will be useful,
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
1312
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
13 Lesser General Public License for more details.
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
14
1312
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
15 You should have received a copy of the GNU Lesser General Public
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
16 License along with this library; if not, write to the Free Software
c9b51268668f Updated copyright information and removed rcs id lines (problematic in branch merges)
Sam Lantinga <slouken@libsdl.org>
parents: 769
diff changeset
17 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
18
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
19 Sam Lantinga
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
20 slouken@libsdl.org
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
21 */
1402
d910939febfa Use consistent identifiers for the various platforms we support.
Sam Lantinga <slouken@libsdl.org>
parents: 1358
diff changeset
22 #include "SDL_config.h"
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
23
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
24 /* An implementation of condition variables using semaphores and mutexes */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
25 /*
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
26 This implementation borrows heavily from the BeOS condition variable
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
27 implementation, written by Christopher Tate and Owen Smith. Thanks!
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
28 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
29
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
30 #include "SDL_thread.h"
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
31
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
32 struct SDL_cond
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
33 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
34 SDL_mutex *lock;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
35 int waiting;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
36 int signals;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
37 SDL_sem *wait_sem;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
38 SDL_sem *wait_done;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
39 };
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
40
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
41 /* Create a condition variable */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
42 SDL_cond * SDL_CreateCond(void)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
43 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
44 SDL_cond *cond;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
45
1336
3692456e7b0f Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents: 1312
diff changeset
46 cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
47 if ( cond ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
48 cond->lock = SDL_CreateMutex();
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
49 cond->wait_sem = SDL_CreateSemaphore(0);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
50 cond->wait_done = SDL_CreateSemaphore(0);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
51 cond->waiting = cond->signals = 0;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
52 if ( ! cond->lock || ! cond->wait_sem || ! cond->wait_done ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
53 SDL_DestroyCond(cond);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
54 cond = NULL;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
55 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
56 } else {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
57 SDL_OutOfMemory();
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
58 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
59 return(cond);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
60 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
61
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
62 /* Destroy a condition variable */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
63 void SDL_DestroyCond(SDL_cond *cond)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
64 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
65 if ( cond ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
66 if ( cond->wait_sem ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
67 SDL_DestroySemaphore(cond->wait_sem);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
68 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
69 if ( cond->wait_done ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
70 SDL_DestroySemaphore(cond->wait_done);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
71 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
72 if ( cond->lock ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
73 SDL_DestroyMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
74 }
1336
3692456e7b0f Use SDL_ prefixed versions of C library functions.
Sam Lantinga <slouken@libsdl.org>
parents: 1312
diff changeset
75 SDL_free(cond);
509
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
76 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
77 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
78
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
79 /* Restart one of the threads that are waiting on the condition variable */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
80 int SDL_CondSignal(SDL_cond *cond)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
81 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
82 if ( ! cond ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
83 SDL_SetError("Passed a NULL condition variable");
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
84 return -1;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
85 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
86
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
87 /* If there are waiting threads not already signalled, then
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
88 signal the condition and wait for the thread to respond.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
89 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
90 SDL_LockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
91 if ( cond->waiting > cond->signals ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
92 ++cond->signals;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
93 SDL_SemPost(cond->wait_sem);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
94 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
95 SDL_SemWait(cond->wait_done);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
96 } else {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
97 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
98 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
99
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
100 return 0;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
101 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
102
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
103 /* Restart all threads that are waiting on the condition variable */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
104 int SDL_CondBroadcast(SDL_cond *cond)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
105 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
106 if ( ! cond ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
107 SDL_SetError("Passed a NULL condition variable");
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
108 return -1;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
109 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
110
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
111 /* If there are waiting threads not already signalled, then
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
112 signal the condition and wait for the thread to respond.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
113 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
114 SDL_LockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
115 if ( cond->waiting > cond->signals ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
116 int i, num_waiting;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
117
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
118 num_waiting = (cond->waiting - cond->signals);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
119 cond->signals = cond->waiting;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
120 for ( i=0; i<num_waiting; ++i ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
121 SDL_SemPost(cond->wait_sem);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
122 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
123 /* Now all released threads are blocked here, waiting for us.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
124 Collect them all (and win fabulous prizes!) :-)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
125 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
126 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
127 for ( i=0; i<num_waiting; ++i ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
128 SDL_SemWait(cond->wait_done);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
129 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
130 } else {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
131 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
132 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
133
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
134 return 0;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
135 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
136
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
137 /* Wait on the condition variable for at most 'ms' milliseconds.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
138 The mutex must be locked before entering this function!
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
139 The mutex is unlocked during the wait, and locked again after the wait.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
140
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
141 Typical use:
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
142
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
143 Thread A:
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
144 SDL_LockMutex(lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
145 while ( ! condition ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
146 SDL_CondWait(cond);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
147 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
148 SDL_UnlockMutex(lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
149
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
150 Thread B:
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
151 SDL_LockMutex(lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
152 ...
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
153 condition = true;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
154 ...
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
155 SDL_UnlockMutex(lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
156 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
157 int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
158 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
159 int retval;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
160
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
161 if ( ! cond ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
162 SDL_SetError("Passed a NULL condition variable");
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
163 return -1;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
164 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
165
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
166 /* Obtain the protection mutex, and increment the number of waiters.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
167 This allows the signal mechanism to only perform a signal if there
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
168 are waiting threads.
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
169 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
170 SDL_LockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
171 ++cond->waiting;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
172 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
173
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
174 /* Unlock the mutex, as is required by condition variable semantics */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
175 SDL_UnlockMutex(mutex);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
176
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
177 /* Wait for a signal */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
178 if ( ms == SDL_MUTEX_MAXWAIT ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
179 retval = SDL_SemWait(cond->wait_sem);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
180 } else {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
181 retval = SDL_SemWaitTimeout(cond->wait_sem, ms);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
182 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
183
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
184 /* Let the signaler know we have completed the wait, otherwise
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
185 the signaler can race ahead and get the condition semaphore
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
186 if we are stopped between the mutex unlock and semaphore wait,
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
187 giving a deadlock. See the following URL for details:
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
188 http://www-classic.be.com/aboutbe/benewsletter/volume_III/Issue40.html
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
189 */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
190 SDL_LockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
191 if ( cond->signals > 0 ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
192 /* If we timed out, we need to eat a condition signal */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
193 if ( retval > 0 ) {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
194 SDL_SemWait(cond->wait_sem);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
195 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
196 /* We always notify the signal thread that we are done */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
197 SDL_SemPost(cond->wait_done);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
198
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
199 /* Signal handshake complete */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
200 --cond->signals;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
201 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
202 --cond->waiting;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
203 SDL_UnlockMutex(cond->lock);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
204
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
205 /* Lock the mutex, as is required by condition variable semantics */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
206 SDL_LockMutex(mutex);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
207
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
208 return retval;
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
209 }
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
210
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
211 /* Wait on the condition variable forever */
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
212 int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
213 {
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
214 return SDL_CondWaitTimeout(cond, mutex, SDL_MUTEX_MAXWAIT);
dad72daf44b3 Added initial support for Dreamcast (thanks HERO!)
Sam Lantinga <slouken@libsdl.org>
parents:
diff changeset
215 }