/
SDL_syscond.c
164 lines (134 loc) · 3.44 KB
/
SDL_syscond.c
1
2
3
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
163
164
/*
SDL - Simple DirectMedia Layer
Copyright (C) 1997-2009 Sam Lantinga
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
Sam Lantinga
slouken@libsdl.org
*/
#include "SDL_config.h"
/*
* GNU pth conditions variables
*
* Patrice Mandin
*/
#include <pth.h>
#include "SDL_thread.h"
#include "SDL_sysmutex_c.h"
struct SDL_cond
{
pth_cond_t condpth_p;
};
/* Create a condition variable */
SDL_cond * SDL_CreateCond(void)
{
SDL_cond *cond;
cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));
if ( cond ) {
if ( pth_cond_init(&(cond->condpth_p)) < 0 ) {
SDL_SetError("pthread_cond_init() failed");
SDL_free(cond);
cond = NULL;
}
} else {
SDL_OutOfMemory();
}
return(cond);
}
/* Destroy a condition variable */
void SDL_DestroyCond(SDL_cond *cond)
{
if ( 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 ( pth_cond_notify(&(cond->condpth_p), FALSE) != 0 ) {
SDL_SetError("pth_cond_notify() 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 ( pth_cond_notify(&(cond->condpth_p), TRUE) != 0 ) {
SDL_SetError("pth_cond_notify() failed");
retval = -1;
}
return retval;
}
/* Wait on the condition variable for at most 'ms' milliseconds.
The mutex must be locked before entering this function!
The mutex is unlocked during the wait, and locked again after the wait.
Typical use:
Thread A:
SDL_LockMutex(lock);
while ( ! condition ) {
SDL_CondWait(cond);
}
SDL_UnlockMutex(lock);
Thread B:
SDL_LockMutex(lock);
...
condition = true;
...
SDL_UnlockMutex(lock);
*/
int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)
{
int retval;
pth_event_t ev;
int sec;
if ( ! cond ) {
SDL_SetError("Passed a NULL condition variable");
return -1;
}
retval = 0;
sec = ms/1000;
ev = pth_event(PTH_EVENT_TIME, pth_timeout(sec,(ms-sec*1000)*1000));
if ( pth_cond_await(&(cond->condpth_p), &(mutex->mutexpth_p), ev) != 0 ) {
SDL_SetError("pth_cond_await() failed");
retval = -1;
}
pth_event_free(ev, PTH_FREE_ALL);
return retval;
}
/* Wait on the condition variable forever */
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 ( pth_cond_await(&(cond->condpth_p), &(mutex->mutexpth_p), NULL) != 0 ) {
SDL_SetError("pth_cond_await() failed");
retval = -1;
}
return retval;
}