1 /* 2 SDL - Simple DirectMedia Layer 3 Copyright (C) 1997-2006 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 (at) libsdl.org 21 */ 22 #include "SDL_config.h" 23 24 /* General event handling code for SDL */ 25 26 #include "SDL.h" 27 #include "SDL_syswm.h" 28 #include "SDL_sysevents.h" 29 #include "SDL_events_c.h" 30 #include "../timer/SDL_timer_c.h" 31 #if !SDL_JOYSTICK_DISABLED 32 #include "../joystick/SDL_joystick_c.h" 33 #endif 34 35 /* Public data -- the event filter */ 36 SDL_EventFilter SDL_EventOK = NULL; 37 Uint8 SDL_ProcessEvents[SDL_NUMEVENTS]; 38 static Uint32 SDL_eventstate = 0; 39 40 /* Private data -- event queue */ 41 #define MAXEVENTS 128 42 static struct { 43 SDL_mutex *lock; 44 int active; 45 int head; 46 int tail; 47 SDL_Event event[MAXEVENTS]; 48 int wmmsg_next; 49 struct SDL_SysWMmsg wmmsg[MAXEVENTS]; 50 } SDL_EventQ; 51 52 /* Private data -- event locking structure */ 53 static struct { 54 SDL_mutex *lock; 55 int safe; 56 } SDL_EventLock; 57 58 /* Thread functions */ 59 static SDL_Thread *SDL_EventThread = NULL; /* Thread handle */ 60 static Uint32 event_thread; /* The event thread id */ 61 62 void SDL_Lock_EventThread(void) 63 { 64 if ( SDL_EventThread && (SDL_ThreadID() != event_thread) ) { 65 /* Grab lock and spin until we're sure event thread stopped */ 66 SDL_mutexP(SDL_EventLock.lock); 67 while ( ! SDL_EventLock.safe ) { 68 SDL_Delay(1); 69 } 70 } 71 } 72 void SDL_Unlock_EventThread(void) 73 { 74 if ( SDL_EventThread && (SDL_ThreadID() != event_thread) ) { 75 SDL_mutexV(SDL_EventLock.lock); 76 } 77 } 78 79 #ifdef __OS2__ 80 /* 81 * We'll increase the priority of GobbleEvents thread, so it will process 82 * events in time for sure! For this, we need the DosSetPriority() API 83 * from the os2.h include file. 84 */ 85 #define INCL_DOSPROCESS 86 #include <os2.h> 87 #include <time.h> 88 #endif 89 90 static int SDLCALL SDL_GobbleEvents(void *unused) 91 { 92 event_thread = SDL_ThreadID(); 93 94 #ifdef __OS2__ 95 #ifdef USE_DOSSETPRIORITY 96 /* Increase thread priority, so it will process events in time for sure! */ 97 DosSetPriority(PRTYS_THREAD, PRTYC_REGULAR, +16, 0); 98 #endif 99 #endif 100 101 while ( SDL_EventQ.active ) { 102 SDL_VideoDevice *video = current_video; 103 SDL_VideoDevice *this = current_video; 104 105 /* Get events from the video subsystem */ 106 if ( video ) { 107 video->PumpEvents(this); 108 } 109 110 /* Queue pending key-repeat events */ 111 SDL_CheckKeyRepeat(); 112 113 #if !SDL_JOYSTICK_DISABLED 114 /* Check for joystick state change */ 115 if ( SDL_numjoysticks && (SDL_eventstate & SDL_JOYEVENTMASK) ) { 116 SDL_JoystickUpdate(); 117 } 118 #endif 119 120 /* Give up the CPU for the rest of our timeslice */ 121 SDL_EventLock.safe = 1; 122 if ( SDL_timer_running ) { 123 SDL_ThreadedTimerCheck(); 124 } 125 SDL_Delay(1); 126 127 /* Check for event locking. 128 On the P of the lock mutex, if the lock is held, this thread 129 will wait until the lock is released before continuing. The 130 safe flag will be set, meaning that the other thread can go 131 about it's business. The safe flag is reset before the V, 132 so as soon as the mutex is free, other threads can see that 133 it's not safe to interfere with the event thread. 134 */ 135 SDL_mutexP(SDL_EventLock.lock); 136 SDL_EventLock.safe = 0; 137 SDL_mutexV(SDL_EventLock.lock); 138 } 139 SDL_SetTimerThreaded(0); 140 event_thread = 0; 141 return(0); 142 } 143 144 static int SDL_StartEventThread(Uint32 flags) 145 { 146 /* Reset everything to zero */ 147 SDL_EventThread = NULL; 148 SDL_memset(&SDL_EventLock, 0, sizeof(SDL_EventLock)); 149 150 /* Create the lock and set ourselves active */ 151 #if !SDL_THREADS_DISABLED 152 SDL_EventQ.lock = SDL_CreateMutex(); 153 if ( SDL_EventQ.lock == NULL ) { 154 #ifdef __MACOS__ /* MacOS classic you can't multithread, so no lock needed */ 155 ; 156 #else 157 return(-1); 158 #endif 159 } 160 #endif /* !SDL_THREADS_DISABLED */ 161 SDL_EventQ.active = 1; 162 163 if ( (flags&SDL_INIT_EVENTTHREAD) == SDL_INIT_EVENTTHREAD ) { 164 SDL_EventLock.lock = SDL_CreateMutex(); 165 if ( SDL_EventLock.lock == NULL ) { 166 return(-1); 167 } 168 SDL_EventLock.safe = 0; 169 170 /* The event thread will handle timers too */ 171 SDL_SetTimerThreaded(2); 172 #if (defined(__WIN32__) && !defined(_WIN32_WCE)) && !defined(HAVE_LIBC) && !defined(__SYMBIAN32__) 173 #undef SDL_CreateThread 174 SDL_EventThread = SDL_CreateThread(SDL_GobbleEvents, NULL, NULL, NULL); 175 #else 176 SDL_EventThread = SDL_CreateThread(SDL_GobbleEvents, NULL); 177 #endif 178 if ( SDL_EventThread == NULL ) { 179 return(-1); 180 } 181 } else { 182 event_thread = 0; 183 } 184 return(0); 185 } 186 187 static void SDL_StopEventThread(void) 188 { 189 SDL_EventQ.active = 0; 190 if ( SDL_EventThread ) { 191 SDL_WaitThread(SDL_EventThread, NULL); 192 SDL_EventThread = NULL; 193 SDL_DestroyMutex(SDL_EventLock.lock); 194 } 195 #ifndef IPOD 196 SDL_DestroyMutex(SDL_EventQ.lock); 197 #endif 198 } 199 200 Uint32 SDL_EventThreadID(void) 201 { 202 return(event_thread); 203 } 204 205 /* Public functions */ 206 207 void SDL_StopEventLoop(void) 208 { 209 /* Halt the event thread, if running */ 210 SDL_StopEventThread(); 211 212 /* Shutdown event handlers */ 213 SDL_AppActiveQuit(); 214 SDL_KeyboardQuit(); 215 SDL_MouseQuit(); 216 SDL_QuitQuit(); 217 218 /* Clean out EventQ */ 219 SDL_EventQ.head = 0; 220 SDL_EventQ.tail = 0; 221 SDL_EventQ.wmmsg_next = 0; 222 } 223 224 /* This function (and associated calls) may be called more than once */ 225 int SDL_StartEventLoop(Uint32 flags) 226 { 227 int retcode; 228 229 /* Clean out the event queue */ 230 SDL_EventThread = NULL; 231 SDL_EventQ.lock = NULL; 232 SDL_StopEventLoop(); 233 234 /* No filter to start with, process most event types */ 235 SDL_EventOK = NULL; 236 SDL_memset(SDL_ProcessEvents,SDL_ENABLE,sizeof(SDL_ProcessEvents)); 237 SDL_eventstate = ~0; 238 /* It's not save to call SDL_EventState() yet */ 239 SDL_eventstate &= ~(0x00000001 << SDL_SYSWMEVENT); 240 SDL_ProcessEvents[SDL_SYSWMEVENT] = SDL_IGNORE; 241 242 /* Initialize event handlers */ 243 retcode = 0; 244 retcode += SDL_AppActiveInit(); 245 retcode += SDL_KeyboardInit(); 246 retcode += SDL_MouseInit(); 247 retcode += SDL_QuitInit(); 248 if ( retcode < 0 ) { 249 /* We don't expect them to fail, but... */ 250 return(-1); 251 } 252 253 /* Create the lock and event thread */ 254 if ( SDL_StartEventThread(flags) < 0 ) { 255 SDL_StopEventLoop(); 256 return(-1); 257 } 258 return(0); 259 } 260 261 262 /* Add an event to the event queue -- called with the queue locked */ 263 static int SDL_AddEvent(SDL_Event *event) 264 { 265 int tail, added; 266 267 tail = (SDL_EventQ.tail+1)%MAXEVENTS; 268 if ( tail == SDL_EventQ.head ) { 269 /* Overflow, drop event */ 270 added = 0; 271 } else { 272 SDL_EventQ.event[SDL_EventQ.tail] = *event; 273 if (event->type == SDL_SYSWMEVENT) { 274 /* Note that it's possible to lose an event */ 275 int next = SDL_EventQ.wmmsg_next; 276 SDL_EventQ.wmmsg[next] = *event->syswm.msg; 277 SDL_EventQ.event[SDL_EventQ.tail].syswm.msg = 278 &SDL_EventQ.wmmsg[next]; 279 SDL_EventQ.wmmsg_next = (next+1)%MAXEVENTS; 280 } 281 SDL_EventQ.tail = tail; 282 added = 1; 283 } 284 return(added); 285 } 286 287 /* Cut an event, and return the next valid spot, or the tail */ 288 /* -- called with the queue locked */ 289 static int SDL_CutEvent(int spot) 290 { 291 if ( spot == SDL_EventQ.head ) { 292 SDL_EventQ.head = (SDL_EventQ.head+1)%MAXEVENTS; 293 return(SDL_EventQ.head); 294 } else 295 if ( (spot+1)%MAXEVENTS == SDL_EventQ.tail ) { 296 SDL_EventQ.tail = spot; 297 return(SDL_EventQ.tail); 298 } else 299 /* We cut the middle -- shift everything over */ 300 { 301 int here, next; 302 303 /* This can probably be optimized with SDL_memcpy() -- careful! */ 304 if ( --SDL_EventQ.tail < 0 ) { 305 SDL_EventQ.tail = MAXEVENTS-1; 306 } 307 for ( here=spot; here != SDL_EventQ.tail; here = next ) { 308 next = (here+1)%MAXEVENTS; 309 SDL_EventQ.event[here] = SDL_EventQ.event[next]; 310 } 311 return(spot); 312 } 313 /* NOTREACHED */ 314 } 315 316 /* Lock the event queue, take a peep at it, and unlock it */ 317 int SDL_PeepEvents(SDL_Event *events, int numevents, SDL_eventaction action, 318 Uint32 mask) 319 { 320 int i, used; 321 322 /* Don't look after we've quit */ 323 if ( ! SDL_EventQ.active ) { 324 return(-1); 325 } 326 /* Lock the event queue */ 327 used = 0; 328 if ( SDL_mutexP(SDL_EventQ.lock) == 0 ) { 329 if ( action == SDL_ADDEVENT ) { 330 for ( i=0; i<numevents; ++i ) { 331 used += SDL_AddEvent(&events[i]); 332 } 333 } else { 334 SDL_Event tmpevent; 335 int spot; 336 337 /* If 'events' is NULL, just see if they exist */ 338 if ( events == NULL ) { 339 action = SDL_PEEKEVENT; 340 numevents = 1; 341 events = &tmpevent; 342 } 343 spot = SDL_EventQ.head; 344 while ((used < numevents)&&(spot != SDL_EventQ.tail)) { 345 if ( mask & SDL_EVENTMASK(SDL_EventQ.event[spot].type) ) { 346 events[used++] = SDL_EventQ.event[spot]; 347 if ( action == SDL_GETEVENT ) { 348 spot = SDL_CutEvent(spot); 349 } else { 350 spot = (spot+1)%MAXEVENTS; 351 } 352 } else { 353 spot = (spot+1)%MAXEVENTS; 354 } 355 } 356 } 357 SDL_mutexV(SDL_EventQ.lock); 358 } else { 359 SDL_SetError("Couldn't lock event queue"); 360 used = -1; 361 } 362 return(used); 363 } 364 365 /* Run the system dependent event loops */ 366 void SDL_PumpEvents(void) 367 { 368 if ( !SDL_EventThread ) { 369 SDL_VideoDevice *video = current_video; 370 SDL_VideoDevice *this = current_video; 371 372 /* Get events from the video subsystem */ 373 if ( video ) { 374 video->PumpEvents(this); 375 } 376 377 /* Queue pending key-repeat events */ 378 SDL_CheckKeyRepeat(); 379 380 #if !SDL_JOYSTICK_DISABLED 381 /* Check for joystick state change */ 382 if ( SDL_numjoysticks && (SDL_eventstate & SDL_JOYEVENTMASK) ) { 383 SDL_JoystickUpdate(); 384 } 385 #endif 386 } 387 } 388 389 /* Public functions */ 390 391 int SDL_PollEvent (SDL_Event *event) 392 { 393 SDL_PumpEvents(); 394 395 /* We can't return -1, just return 0 (no event) on error */ 396 if ( SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_ALLEVENTS) <= 0 ) 397 return 0; 398 return 1; 399 } 400 401 int SDL_WaitEvent (SDL_Event *event) 402 { 403 while ( 1 ) { 404 SDL_PumpEvents(); 405 switch(SDL_PeepEvents(event, 1, SDL_GETEVENT, SDL_ALLEVENTS)) { 406 case -1: return 0; 407 case 1: return 1; 408 case 0: SDL_Delay(10); 409 } 410 } 411 } 412 413 int SDL_PushEvent(SDL_Event *event) 414 { 415 if ( SDL_PeepEvents(event, 1, SDL_ADDEVENT, 0) <= 0 ) 416 return -1; 417 return 0; 418 } 419 420 void SDL_SetEventFilter (SDL_EventFilter filter) 421 { 422 SDL_Event bitbucket; 423 424 /* Set filter and discard pending events */ 425 SDL_EventOK = filter; 426 while ( SDL_PollEvent(&bitbucket) > 0 ) 427 ; 428 } 429 430 SDL_EventFilter SDL_GetEventFilter(void) 431 { 432 return(SDL_EventOK); 433 } 434 435 Uint8 SDL_EventState (Uint8 type, int state) 436 { 437 SDL_Event bitbucket; 438 Uint8 current_state; 439 440 /* If SDL_ALLEVENTS was specified... */ 441 if ( type == 0xFF ) { 442 current_state = SDL_IGNORE; 443 for ( type=0; type<SDL_NUMEVENTS; ++type ) { 444 if ( SDL_ProcessEvents[type] != SDL_IGNORE ) { 445 current_state = SDL_ENABLE; 446 } 447 SDL_ProcessEvents[type] = state; 448 if ( state == SDL_ENABLE ) { 449 SDL_eventstate |= (0x00000001 << (type)); 450 } else { 451 SDL_eventstate &= ~(0x00000001 << (type)); 452 } 453 } 454 while ( SDL_PollEvent(&bitbucket) > 0 ) 455 ; 456 return(current_state); 457 } 458 459 /* Just set the state for one event type */ 460 current_state = SDL_ProcessEvents[type]; 461 switch (state) { 462 case SDL_IGNORE: 463 case SDL_ENABLE: 464 /* Set state and discard pending events */ 465 SDL_ProcessEvents[type] = state; 466 if ( state == SDL_ENABLE ) { 467 SDL_eventstate |= (0x00000001 << (type)); 468 } else { 469 SDL_eventstate &= ~(0x00000001 << (type)); 470 } 471 while ( SDL_PollEvent(&bitbucket) > 0 ) 472 ; 473 break; 474 default: 475 /* Querying state? */ 476 break; 477 } 478 return(current_state); 479 } 480 481 /* This is a generic event handler. 482 */ 483 int SDL_PrivateSysWMEvent(SDL_SysWMmsg *message) 484 { 485 int posted; 486 487 posted = 0; 488 if ( SDL_ProcessEvents[SDL_SYSWMEVENT] == SDL_ENABLE ) { 489 SDL_Event event; 490 SDL_memset(&event, 0, sizeof(event)); 491 event.type = SDL_SYSWMEVENT; 492 event.syswm.msg = message; 493 if ( (SDL_EventOK == NULL) || (*SDL_EventOK)(&event) ) { 494 posted = 1; 495 SDL_PushEvent(&event); 496 } 497 } 498 /* Update internal event state */ 499 return(posted); 500 } 501
