Mercurial > sdl-ios-xcode

annotate src/thread/dc/SDL_syscond.c @ 1402:d910939febfa

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Use consistent identifiers for the various platforms we support. Make sure every source file includes SDL_config.h, so the proper system headers are chosen.
author Sam Lantinga <slouken@libsdl.org>
date Tue, 21 Feb 2006 08:46:50 +0000
parents c71e05b4dc2e
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 }