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comparison src/thread/dc/SDL_syssem.c @ 509:dad72daf44b3

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Added initial support for Dreamcast (thanks HERO!)
author Sam Lantinga <slouken@libsdl.org>
date Sat, 05 Oct 2002 16:50:56 +0000
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children b8d311d90021
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508:9ff7e90aaa94 509:dad72daf44b3
1 /*
2 SDL - Simple DirectMedia Layer
3 Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002 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 BERO
20 bero@geocities.co.jp
21
22 based on generic/SDL_syssem.c
23
24 Sam Lantinga
25 slouken@libsdl.org
26 */
27
28 #ifdef SAVE_RCSID
29 static char rcsid =
30 "@(#) $Id$";
31 #endif
32
33 /* An implementation of semaphores using mutexes and condition variables */
34
35 #include <stdlib.h>
36
37 #include "SDL_error.h"
38 #include "SDL_timer.h"
39 #include "SDL_thread.h"
40 #include "SDL_systhread_c.h"
41
42
43 #ifdef DISABLE_THREADS
44
45 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
46 {
47 SDL_SetError("SDL not configured with thread support");
48 return (SDL_sem *)0;
49 }
50
51 void SDL_DestroySemaphore(SDL_sem *sem)
52 {
53 return;
54 }
55
56 int SDL_SemTryWait(SDL_sem *sem)
57 {
58 SDL_SetError("SDL not configured with thread support");
59 return -1;
60 }
61
62 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
63 {
64 SDL_SetError("SDL not configured with thread support");
65 return -1;
66 }
67
68 int SDL_SemWait(SDL_sem *sem)
69 {
70 SDL_SetError("SDL not configured with thread support");
71 return -1;
72 }
73
74 Uint32 SDL_SemValue(SDL_sem *sem)
75 {
76 return 0;
77 }
78
79 int SDL_SemPost(SDL_sem *sem)
80 {
81 SDL_SetError("SDL not configured with thread support");
82 return -1;
83 }
84
85 #else
86
87 #include <kos/sem.h>
88
89 struct SDL_semaphore
90 {
91 semaphore_t sem;
92 };
93
94 SDL_sem *SDL_CreateSemaphore(Uint32 initial_value)
95 {
96 return (SDL_sem *)sem_create(initial_value);
97 }
98
99 /* WARNING:
100 You cannot call this function when another thread is using the semaphore.
101 */
102 void SDL_DestroySemaphore(SDL_sem *sem)
103 {
104 if ( ! sem ) {
105 SDL_SetError("Passed a NULL semaphore");
106 return;
107 }
108
109 sem_destroy(&sem->sem);
110 }
111
112 int SDL_SemTryWait(SDL_sem *sem)
113 {
114 int retval;
115
116 if ( ! sem ) {
117 SDL_SetError("Passed a NULL semaphore");
118 return -1;
119 }
120
121 retval = sem_trywait(&sem->sem);
122 if (retval==0) return 0;
123 else return SDL_MUTEX_TIMEDOUT;
124
125 return retval;
126 }
127
128 int SDL_SemWaitTimeout(SDL_sem *sem, Uint32 timeout)
129 {
130 int retval;
131
132 if ( ! sem ) {
133 SDL_SetError("Passed a NULL semaphore");
134 return -1;
135 }
136
137 /* A timeout of 0 is an easy case */
138 if ( timeout == 0 ) {
139 return SDL_SemTryWait(sem);
140 }
141
142 retval = sem_wait_timed(&sem->sem,timeout);
143 if (retval==-1) retval= SDL_MUTEX_TIMEDOUT;
144
145 return retval;
146 }
147
148 int SDL_SemWait(SDL_sem *sem)
149 {
150 if ( ! sem ) {
151 SDL_SetError("Passed a NULL semaphore");
152 return -1;
153 }
154
155 sem_wait(&sem->sem);
156 return 0;
157 }
158
159 Uint32 SDL_SemValue(SDL_sem *sem)
160 {
161 if ( ! sem ) {
162 SDL_SetError("Passed a NULL semaphore");
163 return -1;
164 }
165
166 return sem_count(&sem->sem);
167 }
168
169 int SDL_SemPost(SDL_sem *sem)
170 {
171 if ( ! sem ) {
172 SDL_SetError("Passed a NULL semaphore");
173 return -1;
174 }
175
176 sem_signal(&sem->sem);
177 return 0;
178 }
179
180 #endif /* DISABLE_THREADS */