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 "SDL_timer.h" |
25 | #include "SDL_timer_c.h" |
26 | #include "SDL_mutex.h" |
27 | #include "SDL_systimer.h" |
28 | |
29 | /* #define DEBUG_TIMERS */ |
30 | |
31 | int SDL_timer_started = 0; |
32 | int SDL_timer_running = 0; |
33 | |
34 | /* Data to handle a single periodic alarm */ |
35 | Uint32 SDL_alarm_interval = 0; |
36 | SDL_TimerCallback SDL_alarm_callback; |
37 | |
38 | /* Data used for a thread-based timer */ |
39 | static int SDL_timer_threaded = 0; |
40 | |
41 | struct _SDL_TimerID { |
42 | Uint32 interval; |
43 | SDL_NewTimerCallback cb; |
44 | void *param; |
45 | Uint32 last_alarm; |
46 | struct _SDL_TimerID *next; |
47 | }; |
48 | |
49 | static SDL_TimerID SDL_timers = NULL; |
50 | static SDL_mutex *SDL_timer_mutex; |
51 | static volatile SDL_bool list_changed = SDL_FALSE; |
52 | |
53 | /* Set whether or not the timer should use a thread. |
54 | This should not be called while the timer subsystem is running. |
55 | */ |
56 | int SDL_SetTimerThreaded(int value) |
57 | { |
58 | int retval; |
59 | |
60 | if ( SDL_timer_started ) { |
61 | SDL_SetError("Timer already initialized"); |
62 | retval = -1; |
63 | } else { |
64 | retval = 0; |
65 | SDL_timer_threaded = value; |
66 | } |
67 | return retval; |
68 | } |
69 | |
70 | int SDL_TimerInit(void) |
71 | { |
72 | int retval; |
73 | |
74 | retval = 0; |
75 | if ( SDL_timer_started ) { |
76 | SDL_TimerQuit(); |
77 | } |
78 | if ( ! SDL_timer_threaded ) { |
79 | retval = SDL_SYS_TimerInit(); |
80 | } |
81 | if ( SDL_timer_threaded ) { |
82 | SDL_timer_mutex = SDL_CreateMutex(); |
83 | } |
84 | if ( retval == 0 ) { |
85 | SDL_timer_started = 1; |
86 | } |
87 | return(retval); |
88 | } |
89 | |
90 | void SDL_TimerQuit(void) |
91 | { |
92 | SDL_SetTimer(0, NULL); |
93 | if ( SDL_timer_threaded < 2 ) { |
94 | SDL_SYS_TimerQuit(); |
95 | } |
96 | if ( SDL_timer_threaded ) { |
97 | SDL_DestroyMutex(SDL_timer_mutex); |
98 | SDL_timer_mutex = NULL; |
99 | } |
100 | SDL_timer_started = 0; |
101 | SDL_timer_threaded = 0; |
102 | } |
103 | |
104 | void SDL_ThreadedTimerCheck(void) |
105 | { |
106 | Uint32 now, ms; |
107 | SDL_TimerID t, prev, next; |
108 | SDL_bool removed; |
109 | |
110 | SDL_mutexP(SDL_timer_mutex); |
111 | list_changed = SDL_FALSE; |
112 | now = SDL_GetTicks(); |
113 | for ( prev = NULL, t = SDL_timers; t; t = next ) { |
114 | removed = SDL_FALSE; |
115 | ms = t->interval - SDL_TIMESLICE; |
116 | next = t->next; |
117 | if ( (int)(now - t->last_alarm) > (int)ms ) { |
118 | struct _SDL_TimerID timer; |
119 | |
120 | if ( (now - t->last_alarm) < t->interval ) { |
121 | t->last_alarm += t->interval; |
122 | } else { |
123 | t->last_alarm = now; |
124 | } |
125 | #ifdef DEBUG_TIMERS |
126 | printf("Executing timer %p (thread = %d)\n", |
127 | t, SDL_ThreadID()); |
128 | #endif |
129 | timer = *t; |
130 | SDL_mutexV(SDL_timer_mutex); |
131 | ms = timer.cb(timer.interval, timer.param); |
132 | SDL_mutexP(SDL_timer_mutex); |
133 | if ( list_changed ) { |
134 | /* Abort, list of timers modified */ |
135 | /* FIXME: what if ms was changed? */ |
136 | break; |
137 | } |
138 | if ( ms != t->interval ) { |
139 | if ( ms ) { |
140 | t->interval = ROUND_RESOLUTION(ms); |
141 | } else { |
142 | /* Remove timer from the list */ |
143 | #ifdef DEBUG_TIMERS |
144 | printf("SDL: Removing timer %p\n", t); |
145 | #endif |
146 | if ( prev ) { |
147 | prev->next = next; |
148 | } else { |
149 | SDL_timers = next; |
150 | } |
151 | SDL_free(t); |
152 | --SDL_timer_running; |
153 | removed = SDL_TRUE; |
154 | } |
155 | } |
156 | } |
157 | /* Don't update prev if the timer has disappeared */ |
158 | if ( ! removed ) { |
159 | prev = t; |
160 | } |
161 | } |
162 | SDL_mutexV(SDL_timer_mutex); |
163 | } |
164 | |
165 | static SDL_TimerID SDL_AddTimerInternal(Uint32 interval, SDL_NewTimerCallback callback, void *param) |
166 | { |
167 | SDL_TimerID t; |
168 | t = (SDL_TimerID) SDL_malloc(sizeof(struct _SDL_TimerID)); |
169 | if ( t ) { |
170 | t->interval = ROUND_RESOLUTION(interval); |
171 | t->cb = callback; |
172 | t->param = param; |
173 | t->last_alarm = SDL_GetTicks(); |
174 | t->next = SDL_timers; |
175 | SDL_timers = t; |
176 | ++SDL_timer_running; |
177 | list_changed = SDL_TRUE; |
178 | } |
179 | #ifdef DEBUG_TIMERS |
180 | printf("SDL_AddTimer(%d) = %08x num_timers = %d\n", interval, (Uint32)t, SDL_timer_running); |
181 | #endif |
182 | return t; |
183 | } |
184 | |
185 | SDL_TimerID SDL_AddTimer(Uint32 interval, SDL_NewTimerCallback callback, void *param) |
186 | { |
187 | SDL_TimerID t; |
188 | if ( ! SDL_timer_mutex ) { |
189 | if ( SDL_timer_started ) { |
190 | SDL_SetError("This platform doesn't support multiple timers"); |
191 | } else { |
192 | SDL_SetError("You must call SDL_Init(SDL_INIT_TIMER) first"); |
193 | } |
194 | return NULL; |
195 | } |
196 | if ( ! SDL_timer_threaded ) { |
197 | SDL_SetError("Multiple timers require threaded events!"); |
198 | return NULL; |
199 | } |
200 | SDL_mutexP(SDL_timer_mutex); |
201 | t = SDL_AddTimerInternal(interval, callback, param); |
202 | SDL_mutexV(SDL_timer_mutex); |
203 | return t; |
204 | } |
205 | |
206 | SDL_bool SDL_RemoveTimer(SDL_TimerID id) |
207 | { |
208 | SDL_TimerID t, prev = NULL; |
209 | SDL_bool removed; |
210 | |
211 | removed = SDL_FALSE; |
212 | SDL_mutexP(SDL_timer_mutex); |
213 | /* Look for id in the linked list of timers */ |
214 | for (t = SDL_timers; t; prev=t, t = t->next ) { |
215 | if ( t == id ) { |
216 | if(prev) { |
217 | prev->next = t->next; |
218 | } else { |
219 | SDL_timers = t->next; |
220 | } |
221 | SDL_free(t); |
222 | --SDL_timer_running; |
223 | removed = SDL_TRUE; |
224 | list_changed = SDL_TRUE; |
225 | break; |
226 | } |
227 | } |
228 | #ifdef DEBUG_TIMERS |
229 | printf("SDL_RemoveTimer(%08x) = %d num_timers = %d thread = %d\n", (Uint32)id, removed, SDL_timer_running, SDL_ThreadID()); |
230 | #endif |
231 | SDL_mutexV(SDL_timer_mutex); |
232 | return removed; |
233 | } |
234 | |
235 | /* Old style callback functions are wrapped through this */ |
236 | static Uint32 SDLCALL callback_wrapper(Uint32 ms, void *param) |
237 | { |
238 | SDL_TimerCallback func = (SDL_TimerCallback) param; |
239 | return (*func)(ms); |
240 | } |
241 | |
242 | int SDL_SetTimer(Uint32 ms, SDL_TimerCallback callback) |
243 | { |
244 | int retval; |
245 | |
246 | #ifdef DEBUG_TIMERS |
247 | printf("SDL_SetTimer(%d)\n", ms); |
248 | #endif |
249 | retval = 0; |
250 | |
251 | if ( SDL_timer_threaded ) { |
252 | SDL_mutexP(SDL_timer_mutex); |
253 | } |
254 | if ( SDL_timer_running ) { /* Stop any currently running timer */ |
255 | if ( SDL_timer_threaded ) { |
256 | while ( SDL_timers ) { |
257 | SDL_TimerID freeme = SDL_timers; |
258 | SDL_timers = SDL_timers->next; |
259 | SDL_free(freeme); |
260 | } |
261 | SDL_timer_running = 0; |
262 | list_changed = SDL_TRUE; |
263 | } else { |
264 | SDL_SYS_StopTimer(); |
265 | SDL_timer_running = 0; |
266 | } |
267 | } |
268 | if ( ms ) { |
269 | if ( SDL_timer_threaded ) { |
270 | if ( SDL_AddTimerInternal(ms, callback_wrapper, (void *)callback) == NULL ) { |
271 | retval = -1; |
272 | } |
273 | } else { |
274 | SDL_timer_running = 1; |
275 | SDL_alarm_interval = ms; |
276 | SDL_alarm_callback = callback; |
277 | retval = SDL_SYS_StartTimer(); |
278 | } |
279 | } |
280 | if ( SDL_timer_threaded ) { |
281 | SDL_mutexV(SDL_timer_mutex); |
282 | } |
283 | |
284 | return retval; |
285 | } |