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 #ifdef SDL_TIMER_UNIX
25
26 #include <stdio.h>
27 #include <sys/time.h>
28 #include <signal.h>
29 #include <unistd.h>
30 #include <string.h>
31 #include <errno.h>
32
33 #include "SDL_timer.h"
34 #include "../SDL_timer_c.h"
35
36 /* The clock_gettime provides monotonous time, so we should use it if
37 it's available. The clock_gettime function is behind ifdef
38 for __USE_POSIX199309
39 Tommi Kyntola (tommi.kyntola@ray.fi) 27/09/2005
40 */
41 #if HAVE_NANOSLEEP || HAVE_CLOCK_GETTIME
42 #include <time.h>
43 #endif
44
45 #if SDL_THREAD_PTH
46 #include <pth.h>
47 #endif
48
49 #if SDL_THREADS_DISABLED
50 #define USE_ITIMER
51 #endif
52
53 /* The first ticks value of the application */
54 #ifdef HAVE_CLOCK_GETTIME
55 static struct timespec start;
56 #else
57 static struct timeval start;
58 #endif /* HAVE_CLOCK_GETTIME */
59
60
SDL_StartTicks(void)61 void SDL_StartTicks(void)
62 {
63 /* Set first ticks value */
64 #if HAVE_CLOCK_GETTIME
65 clock_gettime(CLOCK_MONOTONIC,&start);
66 #else
67 gettimeofday(&start, NULL);
68 #endif
69 }
70
SDL_GetTicks(void)71 Uint32 SDL_GetTicks (void)
72 {
73 #if HAVE_CLOCK_GETTIME
74 Uint32 ticks;
75 struct timespec now;
76 clock_gettime(CLOCK_MONOTONIC,&now);
77 ticks=(now.tv_sec-start.tv_sec)*1000+(now.tv_nsec-start.tv_nsec)/1000000;
78 return(ticks);
79 #else
80 Uint32 ticks;
81 struct timeval now;
82 gettimeofday(&now, NULL);
83 ticks=(now.tv_sec-start.tv_sec)*1000+(now.tv_usec-start.tv_usec)/1000;
84 return(ticks);
85 #endif
86 }
87
SDL_Delay(Uint32 ms)88 void SDL_Delay (Uint32 ms)
89 {
90 #if SDL_THREAD_PTH
91 pth_time_t tv;
92 tv.tv_sec = ms/1000;
93 tv.tv_usec = (ms%1000)*1000;
94 pth_nap(tv);
95 #else
96 int was_error;
97
98 #if HAVE_NANOSLEEP
99 struct timespec elapsed, tv;
100 #else
101 struct timeval tv;
102 Uint32 then, now, elapsed;
103 #endif
104
105 /* Set the timeout interval */
106 #if HAVE_NANOSLEEP
107 elapsed.tv_sec = ms/1000;
108 elapsed.tv_nsec = (ms%1000)*1000000;
109 #else
110 then = SDL_GetTicks();
111 #endif
112 do {
113 errno = 0;
114
115 #if HAVE_NANOSLEEP
116 tv.tv_sec = elapsed.tv_sec;
117 tv.tv_nsec = elapsed.tv_nsec;
118 was_error = nanosleep(&tv, &elapsed);
119 #else
120 /* Calculate the time interval left (in case of interrupt) */
121 now = SDL_GetTicks();
122 elapsed = (now-then);
123 then = now;
124 if ( elapsed >= ms ) {
125 break;
126 }
127 ms -= elapsed;
128 tv.tv_sec = ms/1000;
129 tv.tv_usec = (ms%1000)*1000;
130
131 was_error = select(0, NULL, NULL, NULL, &tv);
132 #endif /* HAVE_NANOSLEEP */
133 } while ( was_error && (errno == EINTR) );
134 #endif /* SDL_THREAD_PTH */
135 }
136
137 #ifdef USE_ITIMER
138
HandleAlarm(int sig)139 static void HandleAlarm(int sig)
140 {
141 Uint32 ms;
142
143 if ( SDL_alarm_callback ) {
144 ms = (*SDL_alarm_callback)(SDL_alarm_interval);
145 if ( ms != SDL_alarm_interval ) {
146 SDL_SetTimer(ms, SDL_alarm_callback);
147 }
148 }
149 }
150
SDL_SYS_TimerInit(void)151 int SDL_SYS_TimerInit(void)
152 {
153 struct sigaction action;
154
155 /* Set the alarm handler (Linux specific) */
156 SDL_memset(&action, 0, sizeof(action));
157 action.sa_handler = HandleAlarm;
158 action.sa_flags = SA_RESTART;
159 sigemptyset(&action.sa_mask);
160 sigaction(SIGALRM, &action, NULL);
161 return(0);
162 }
163
SDL_SYS_TimerQuit(void)164 void SDL_SYS_TimerQuit(void)
165 {
166 SDL_SetTimer(0, NULL);
167 }
168
SDL_SYS_StartTimer(void)169 int SDL_SYS_StartTimer(void)
170 {
171 struct itimerval timer;
172
173 timer.it_value.tv_sec = (SDL_alarm_interval/1000);
174 timer.it_value.tv_usec = (SDL_alarm_interval%1000)*1000;
175 timer.it_interval.tv_sec = (SDL_alarm_interval/1000);
176 timer.it_interval.tv_usec = (SDL_alarm_interval%1000)*1000;
177 setitimer(ITIMER_REAL, &timer, NULL);
178 return(0);
179 }
180
SDL_SYS_StopTimer(void)181 void SDL_SYS_StopTimer(void)
182 {
183 struct itimerval timer;
184
185 SDL_memset(&timer, 0, (sizeof timer));
186 setitimer(ITIMER_REAL, &timer, NULL);
187 }
188
189 #else /* USE_ITIMER */
190
191 #include "SDL_thread.h"
192
193 /* Data to handle a single periodic alarm */
194 static int timer_alive = 0;
195 static SDL_Thread *timer = NULL;
196
RunTimer(void * unused)197 static int RunTimer(void *unused)
198 {
199 while ( timer_alive ) {
200 if ( SDL_timer_running ) {
201 SDL_ThreadedTimerCheck();
202 }
203 SDL_Delay(1);
204 }
205 return(0);
206 }
207
208 /* This is only called if the event thread is not running */
SDL_SYS_TimerInit(void)209 int SDL_SYS_TimerInit(void)
210 {
211 timer_alive = 1;
212 timer = SDL_CreateThread(RunTimer, NULL);
213 if ( timer == NULL )
214 return(-1);
215 return(SDL_SetTimerThreaded(1));
216 }
217
SDL_SYS_TimerQuit(void)218 void SDL_SYS_TimerQuit(void)
219 {
220 timer_alive = 0;
221 if ( timer ) {
222 SDL_WaitThread(timer, NULL);
223 timer = NULL;
224 }
225 }
226
SDL_SYS_StartTimer(void)227 int SDL_SYS_StartTimer(void)
228 {
229 SDL_SetError("Internal logic error: Linux uses threaded timer");
230 return(-1);
231 }
232
SDL_SYS_StopTimer(void)233 void SDL_SYS_StopTimer(void)
234 {
235 return;
236 }
237
238 #endif /* USE_ITIMER */
239
240 #endif /* SDL_TIMER_UNIX */
241