This repository has been archived by the owner on Feb 11, 2021. It is now read-only.
SDL_syscond.c
1
2
/*
Simple DirectMedia Layer
3
Copyright (C) 1997-2013 Sam Lantinga <slouken@libsdl.org>
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
This software is provided 'as-is', without any express or implied
warranty. In no event will the authors be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this software must not be misrepresented; you must not
claim that you wrote the original software. If you use this software
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original software.
3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_config.h"
#include <sys/time.h>
#include <unistd.h>
#include <errno.h>
#include <pthread.h>
#include "SDL_thread.h"
#include "SDL_sysmutex_c.h"
struct SDL_cond
{
pthread_cond_t cond;
};
/* Create a condition variable */
SDL_cond *
SDL_CreateCond(void)
{
SDL_cond *cond;
cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
if (cond) {
if (pthread_cond_init(&cond->cond, NULL) < 0) {
SDL_SetError("pthread_cond_init() failed");
SDL_free(cond);
cond = NULL;
}
}
return (cond);
}
/* Destroy a condition variable */
void
SDL_DestroyCond(SDL_cond * cond)
{
if (cond) {
pthread_cond_destroy(&cond->cond);
SDL_free(cond);
}
}
/* Restart one of the threads that are waiting on the condition variable */
int
SDL_CondSignal(SDL_cond * cond)
{
int retval;
if (!cond) {
SDL_SetError("Passed a NULL condition variable");
return -1;
}
retval = 0;
if (pthread_cond_signal(&cond->cond) != 0) {
SDL_SetError("pthread_cond_signal() failed");
retval = -1;
}
return retval;
}
/* Restart all threads that are waiting on the condition variable */
int
SDL_CondBroadcast(SDL_cond * cond)
{
int retval;
if (!cond) {
SDL_SetError("Passed a NULL condition variable");
return -1;
}
retval = 0;
if (pthread_cond_broadcast(&cond->cond) != 0) {
SDL_SetError("pthread_cond_broadcast() failed");
retval = -1;
}
return retval;
}
int
SDL_CondWaitTimeout(SDL_cond * cond, SDL_mutex * mutex, Uint32 ms)
{
int retval;
struct timeval delta;
struct timespec abstime;
if (!cond) {
SDL_SetError("Passed a NULL condition variable");
return -1;
}
gettimeofday(&delta, NULL);
abstime.tv_sec = delta.tv_sec + (ms / 1000);
abstime.tv_nsec = (delta.tv_usec + (ms % 1000) * 1000) * 1000;
if (abstime.tv_nsec > 1000000000) {
abstime.tv_sec += 1;
abstime.tv_nsec -= 1000000000;
}
tryagain:
retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);
switch (retval) {
case EINTR:
goto tryagain;
break;
case ETIMEDOUT:
retval = SDL_MUTEX_TIMEDOUT;
break;
case 0:
break;
default:
SDL_SetError("pthread_cond_timedwait() failed");
retval = -1;
break;
}
return retval;
}
/* Wait on the condition variable, unlocking the provided mutex.
The mutex must be locked before entering this function!
*/
int
SDL_CondWait(SDL_cond * cond, SDL_mutex * mutex)
{
int retval;
if (!cond) {
SDL_SetError("Passed a NULL condition variable");
return -1;
}
retval = 0;
if (pthread_cond_wait(&cond->cond, &mutex->id) != 0) {
SDL_SetError("pthread_cond_wait() failed");
retval = -1;
}
return retval;
}
/* vi: set ts=4 sw=4 expandtab: */