e14743d1 |
1 | /* |
2 | SDL - Simple DirectMedia Layer |
3 | Copyright (C) 1997-2009 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 | #include <sys/time.h> |
25 | #include <unistd.h> |
26 | #include <errno.h> |
27 | #include <pthread.h> |
28 | |
29 | #include "SDL_thread.h" |
30 | #include "SDL_sysmutex_c.h" |
31 | |
32 | struct SDL_cond |
33 | { |
34 | pthread_cond_t cond; |
35 | }; |
36 | |
37 | /* Create a condition variable */ |
38 | SDL_cond * SDL_CreateCond(void) |
39 | { |
40 | SDL_cond *cond; |
41 | |
42 | cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond)); |
43 | if ( cond ) { |
44 | if ( pthread_cond_init(&cond->cond, NULL) < 0 ) { |
45 | SDL_SetError("pthread_cond_init() failed"); |
46 | SDL_free(cond); |
47 | cond = NULL; |
48 | } |
49 | } |
50 | return(cond); |
51 | } |
52 | |
53 | /* Destroy a condition variable */ |
54 | void SDL_DestroyCond(SDL_cond *cond) |
55 | { |
56 | if ( cond ) { |
57 | pthread_cond_destroy(&cond->cond); |
58 | SDL_free(cond); |
59 | } |
60 | } |
61 | |
62 | /* Restart one of the threads that are waiting on the condition variable */ |
63 | int SDL_CondSignal(SDL_cond *cond) |
64 | { |
65 | int retval; |
66 | |
67 | if ( ! cond ) { |
68 | SDL_SetError("Passed a NULL condition variable"); |
69 | return -1; |
70 | } |
71 | |
72 | retval = 0; |
73 | if ( pthread_cond_signal(&cond->cond) != 0 ) { |
74 | SDL_SetError("pthread_cond_signal() failed"); |
75 | retval = -1; |
76 | } |
77 | return retval; |
78 | } |
79 | |
80 | /* Restart all threads that are waiting on the condition variable */ |
81 | int SDL_CondBroadcast(SDL_cond *cond) |
82 | { |
83 | int retval; |
84 | |
85 | if ( ! cond ) { |
86 | SDL_SetError("Passed a NULL condition variable"); |
87 | return -1; |
88 | } |
89 | |
90 | retval = 0; |
91 | if ( pthread_cond_broadcast(&cond->cond) != 0 ) { |
92 | SDL_SetError("pthread_cond_broadcast() failed"); |
93 | retval = -1; |
94 | } |
95 | return retval; |
96 | } |
97 | |
98 | int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms) |
99 | { |
100 | int retval; |
101 | struct timeval delta; |
102 | struct timespec abstime; |
103 | |
104 | if ( ! cond ) { |
105 | SDL_SetError("Passed a NULL condition variable"); |
106 | return -1; |
107 | } |
108 | |
109 | gettimeofday(&delta, NULL); |
110 | |
111 | abstime.tv_sec = delta.tv_sec + (ms/1000); |
112 | abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000; |
113 | if ( abstime.tv_nsec > 1000000000 ) { |
114 | abstime.tv_sec += 1; |
115 | abstime.tv_nsec -= 1000000000; |
116 | } |
117 | |
118 | tryagain: |
119 | retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime); |
120 | switch (retval) { |
121 | case EINTR: |
122 | goto tryagain; |
123 | break; |
124 | case ETIMEDOUT: |
125 | retval = SDL_MUTEX_TIMEDOUT; |
126 | break; |
127 | case 0: |
128 | break; |
129 | default: |
130 | SDL_SetError("pthread_cond_timedwait() failed"); |
131 | retval = -1; |
132 | break; |
133 | } |
134 | return retval; |
135 | } |
136 | |
137 | /* Wait on the condition variable, unlocking the provided mutex. |
138 | The mutex must be locked before entering this function! |
139 | */ |
140 | int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex) |
141 | { |
142 | int retval; |
143 | |
144 | if ( ! cond ) { |
145 | SDL_SetError("Passed a NULL condition variable"); |
146 | return -1; |
147 | } |
148 | |
149 | retval = 0; |
150 | if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) { |
151 | SDL_SetError("pthread_cond_wait() failed"); |
152 | retval = -1; |
153 | } |
154 | return retval; |
155 | } |