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 #include "SDL_config.h"
23
24 /* RISC OS implementations uses pthreads based on linux code */
25
26 #if SDL_THREADS_DISABLED
27 #include "../generic/SDL_syscond.c"
28 #else
29 #include <sys/time.h>
30 #include <unistd.h>
31 #include <pthread.h>
32
33 #include "SDL_thread.h"
34 #include "SDL_sysmutex_c.h"
35
36 struct SDL_cond
37 {
38 pthread_cond_t cond;
39 };
40
41 /* Create a condition variable */
SDL_CreateCond(void)42 SDL_cond * SDL_CreateCond(void)
43 {
44 SDL_cond *cond;
45
46 cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
47 if ( cond ) {
48 if ( pthread_cond_init(&cond->cond, NULL) < 0 ) {
49 SDL_SetError("pthread_cond_init() failed");
50 SDL_free(cond);
51 cond = NULL;
52 }
53 }
54 return(cond);
55 }
56
57 /* Destroy a condition variable */
SDL_DestroyCond(SDL_cond * cond)58 void SDL_DestroyCond(SDL_cond *cond)
59 {
60 if ( cond ) {
61 pthread_cond_destroy(&cond->cond);
62 SDL_free(cond);
63 }
64 }
65
66 /* Restart one of the threads that are waiting on the condition variable */
SDL_CondSignal(SDL_cond * cond)67 int SDL_CondSignal(SDL_cond *cond)
68 {
69 int retval;
70
71 if ( ! cond ) {
72 SDL_SetError("Passed a NULL condition variable");
73 return -1;
74 }
75
76 retval = 0;
77 if ( pthread_cond_signal(&cond->cond) != 0 ) {
78 SDL_SetError("pthread_cond_signal() failed");
79 retval = -1;
80 }
81 return retval;
82 }
83
84 /* Restart all threads that are waiting on the condition variable */
SDL_CondBroadcast(SDL_cond * cond)85 int SDL_CondBroadcast(SDL_cond *cond)
86 {
87 int retval;
88
89 if ( ! cond ) {
90 SDL_SetError("Passed a NULL condition variable");
91 return -1;
92 }
93
94 retval = 0;
95 if ( pthread_cond_broadcast(&cond->cond) != 0 ) {
96 SDL_SetError("pthread_cond_broadcast() failed");
97 retval = -1;
98 }
99 return retval;
100 }
101
SDL_CondWaitTimeout(SDL_cond * cond,SDL_mutex * mutex,Uint32 ms)102 int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
103 {
104 int retval;
105 struct timeval delta;
106 struct timespec abstime;
107
108 if ( ! cond ) {
109 SDL_SetError("Passed a NULL condition variable");
110 return -1;
111 }
112
113 gettimeofday(&delta, NULL);
114
115 abstime.tv_sec = delta.tv_sec + (ms/1000);
116 abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000;
117 if ( abstime.tv_nsec > 1000000000 ) {
118 abstime.tv_sec += 1;
119 abstime.tv_nsec -= 1000000000;
120 }
121
122 tryagain:
123 retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);
124 switch (retval) {
125 case EINTR:
126 goto tryagain;
127 break;
128 case ETIMEDOUT:
129 retval = SDL_MUTEX_TIMEDOUT;
130 break;
131 case 0:
132 break;
133 default:
134 SDL_SetError("pthread_cond_timedwait() failed");
135 retval = -1;
136 break;
137 }
138 return retval;
139 }
140
141 /* Wait on the condition variable, unlocking the provided mutex.
142 The mutex must be locked before entering this function!
143 */
SDL_CondWait(SDL_cond * cond,SDL_mutex * mutex)144 int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)
145 {
146 int retval;
147
148 if ( ! cond ) {
149 SDL_SetError("Passed a NULL condition variable");
150 return -1;
151 }
152
153 retval = 0;
154 if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) {
155 SDL_SetError("pthread_cond_wait() failed");
156 retval = -1;
157 }
158 return retval;
159 }
160 #endif
161