| 1 | /* This file is part of the program psim. |
| 2 | |
| 3 | Copyright (C) 1994-1998, Andrew Cagney <cagney@highland.com.au> |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 3 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program 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 |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, see <http://www.gnu.org/licenses/>. |
| 17 | |
| 18 | */ |
| 19 | |
| 20 | |
| 21 | #ifndef _EVENTS_C_ |
| 22 | #define _EVENTS_C_ |
| 23 | |
| 24 | #include "basics.h" |
| 25 | #include "events.h" |
| 26 | |
| 27 | #include <signal.h> |
| 28 | #include <stdlib.h> |
| 29 | |
| 30 | #if !defined (SIM_EVENTS_POLL_RATE) |
| 31 | #define SIM_EVENTS_POLL_RATE 0x1000 |
| 32 | #endif |
| 33 | |
| 34 | |
| 35 | |
| 36 | /* The event queue maintains a single absolute time using two |
| 37 | variables. |
| 38 | |
| 39 | TIME_OF_EVENT: this holds the time at which the next event is ment |
| 40 | to occure. If no next event it will hold the time of the last |
| 41 | event. |
| 42 | |
| 43 | TIME_FROM_EVENT: The current distance from TIME_OF_EVENT. If an |
| 44 | event is pending, this will be positive. If no future event is |
| 45 | pending this will be negative. This variable is decremented once |
| 46 | for each iteration of a clock cycle. |
| 47 | |
| 48 | Initially, the clock is started at time one (1) with TIME_OF_EVENT |
| 49 | == 0 and TIME_FROM_EVENT == -1. |
| 50 | |
| 51 | Clearly there is a bug in that this code assumes that the absolute |
| 52 | time counter will never become greater than 2^62. */ |
| 53 | |
| 54 | typedef struct _event_entry event_entry; |
| 55 | struct _event_entry { |
| 56 | void *data; |
| 57 | event_handler *handler; |
| 58 | signed64 time_of_event; |
| 59 | event_entry *next; |
| 60 | }; |
| 61 | |
| 62 | struct _event_queue { |
| 63 | int processing; |
| 64 | event_entry *queue; |
| 65 | event_entry *volatile held; |
| 66 | event_entry *volatile *volatile held_end; |
| 67 | signed64 time_of_event; |
| 68 | signed64 time_from_event; |
| 69 | }; |
| 70 | |
| 71 | |
| 72 | STATIC_INLINE_EVENTS\ |
| 73 | (void) |
| 74 | sim_events_poll (void *data) |
| 75 | { |
| 76 | event_queue *queue = data; |
| 77 | /* just re-schedule in 1000 million ticks time */ |
| 78 | event_queue_schedule (queue, SIM_EVENTS_POLL_RATE, sim_events_poll, queue); |
| 79 | sim_io_poll_quit (); |
| 80 | } |
| 81 | |
| 82 | |
| 83 | INLINE_EVENTS\ |
| 84 | (event_queue *) |
| 85 | event_queue_create(void) |
| 86 | { |
| 87 | event_queue *new_event_queue = ZALLOC(event_queue); |
| 88 | |
| 89 | new_event_queue->processing = 0; |
| 90 | new_event_queue->queue = NULL; |
| 91 | new_event_queue->held = NULL; |
| 92 | new_event_queue->held_end = &new_event_queue->held; |
| 93 | |
| 94 | /* both times are already zero */ |
| 95 | return new_event_queue; |
| 96 | } |
| 97 | |
| 98 | |
| 99 | INLINE_EVENTS\ |
| 100 | (void) |
| 101 | event_queue_init(event_queue *queue) |
| 102 | { |
| 103 | event_entry *event; |
| 104 | |
| 105 | /* drain the interrupt queue */ |
| 106 | { |
| 107 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 108 | sigset_t old_mask; |
| 109 | sigset_t new_mask; |
| 110 | sigfillset(&new_mask); |
| 111 | /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); |
| 112 | #endif |
| 113 | event = queue->held; |
| 114 | while (event != NULL) { |
| 115 | event_entry *dead = event; |
| 116 | event = event->next; |
| 117 | free(dead); |
| 118 | } |
| 119 | queue->held = NULL; |
| 120 | queue->held_end = &queue->held; |
| 121 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 122 | /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); |
| 123 | #endif |
| 124 | } |
| 125 | |
| 126 | /* drain the normal queue */ |
| 127 | event = queue->queue; |
| 128 | while (event != NULL) { |
| 129 | event_entry *dead = event; |
| 130 | event = event->next; |
| 131 | free(dead); |
| 132 | } |
| 133 | queue->queue = NULL; |
| 134 | |
| 135 | /* wind time back to one */ |
| 136 | queue->processing = 0; |
| 137 | queue->time_of_event = 0; |
| 138 | queue->time_from_event = -1; |
| 139 | |
| 140 | /* schedule our initial counter event */ |
| 141 | event_queue_schedule (queue, 0, sim_events_poll, queue); |
| 142 | } |
| 143 | |
| 144 | INLINE_EVENTS\ |
| 145 | (signed64) |
| 146 | event_queue_time(event_queue *queue) |
| 147 | { |
| 148 | return queue->time_of_event - queue->time_from_event; |
| 149 | } |
| 150 | |
| 151 | STATIC_INLINE_EVENTS\ |
| 152 | (void) |
| 153 | update_time_from_event(event_queue *events) |
| 154 | { |
| 155 | signed64 current_time = event_queue_time(events); |
| 156 | if (events->queue != NULL) { |
| 157 | events->time_from_event = (events->queue->time_of_event - current_time); |
| 158 | events->time_of_event = events->queue->time_of_event; |
| 159 | } |
| 160 | else { |
| 161 | events->time_of_event = current_time - 1; |
| 162 | events->time_from_event = -1; |
| 163 | } |
| 164 | if (WITH_TRACE && ppc_trace[trace_events]) |
| 165 | { |
| 166 | event_entry *event; |
| 167 | int i; |
| 168 | for (event = events->queue, i = 0; |
| 169 | event != NULL; |
| 170 | event = event->next, i++) |
| 171 | { |
| 172 | TRACE(trace_events, ("event time-from-event - time %ld, delta %ld - event %d, tag 0x%lx, time %ld, handler 0x%lx, data 0x%lx\n", |
| 173 | (long)current_time, |
| 174 | (long)events->time_from_event, |
| 175 | i, |
| 176 | (long)event, |
| 177 | (long)event->time_of_event, |
| 178 | (long)event->handler, |
| 179 | (long)event->data)); |
| 180 | } |
| 181 | } |
| 182 | ASSERT(current_time == event_queue_time(events)); |
| 183 | } |
| 184 | |
| 185 | STATIC_INLINE_EVENTS\ |
| 186 | (void) |
| 187 | insert_event_entry(event_queue *events, |
| 188 | event_entry *new_event, |
| 189 | signed64 delta) |
| 190 | { |
| 191 | event_entry *curr; |
| 192 | event_entry **prev; |
| 193 | signed64 time_of_event; |
| 194 | |
| 195 | if (delta < 0) |
| 196 | error("what is past is past!\n"); |
| 197 | |
| 198 | /* compute when the event should occure */ |
| 199 | time_of_event = event_queue_time(events) + delta; |
| 200 | |
| 201 | /* find the queue insertion point - things are time ordered */ |
| 202 | prev = &events->queue; |
| 203 | curr = events->queue; |
| 204 | while (curr != NULL && time_of_event >= curr->time_of_event) { |
| 205 | ASSERT(curr->next == NULL |
| 206 | || curr->time_of_event <= curr->next->time_of_event); |
| 207 | prev = &curr->next; |
| 208 | curr = curr->next; |
| 209 | } |
| 210 | ASSERT(curr == NULL || time_of_event < curr->time_of_event); |
| 211 | |
| 212 | /* insert it */ |
| 213 | new_event->next = curr; |
| 214 | *prev = new_event; |
| 215 | new_event->time_of_event = time_of_event; |
| 216 | |
| 217 | /* adjust the time until the first event */ |
| 218 | update_time_from_event(events); |
| 219 | } |
| 220 | |
| 221 | INLINE_EVENTS\ |
| 222 | (event_entry_tag) |
| 223 | event_queue_schedule(event_queue *events, |
| 224 | signed64 delta_time, |
| 225 | event_handler *handler, |
| 226 | void *data) |
| 227 | { |
| 228 | event_entry *new_event = ZALLOC(event_entry); |
| 229 | new_event->data = data; |
| 230 | new_event->handler = handler; |
| 231 | insert_event_entry(events, new_event, delta_time); |
| 232 | TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", |
| 233 | (long)event_queue_time(events), |
| 234 | (long)new_event, |
| 235 | (long)new_event->time_of_event, |
| 236 | (long)new_event->handler, |
| 237 | (long)new_event->data)); |
| 238 | return (event_entry_tag)new_event; |
| 239 | } |
| 240 | |
| 241 | |
| 242 | INLINE_EVENTS\ |
| 243 | (event_entry_tag) |
| 244 | event_queue_schedule_after_signal(event_queue *events, |
| 245 | signed64 delta_time, |
| 246 | event_handler *handler, |
| 247 | void *data) |
| 248 | { |
| 249 | event_entry *new_event = ZALLOC(event_entry); |
| 250 | |
| 251 | new_event->data = data; |
| 252 | new_event->handler = handler; |
| 253 | new_event->time_of_event = delta_time; /* work it out later */ |
| 254 | new_event->next = NULL; |
| 255 | |
| 256 | { |
| 257 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 258 | sigset_t old_mask; |
| 259 | sigset_t new_mask; |
| 260 | sigfillset(&new_mask); |
| 261 | /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); |
| 262 | #endif |
| 263 | if (events->held == NULL) { |
| 264 | events->held = new_event; |
| 265 | } |
| 266 | else { |
| 267 | *events->held_end = new_event; |
| 268 | } |
| 269 | events->held_end = &new_event->next; |
| 270 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 271 | /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); |
| 272 | #endif |
| 273 | } |
| 274 | |
| 275 | TRACE(trace_events, ("event scheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", |
| 276 | (long)event_queue_time(events), |
| 277 | (long)new_event, |
| 278 | (long)new_event->time_of_event, |
| 279 | (long)new_event->handler, |
| 280 | (long)new_event->data)); |
| 281 | |
| 282 | return (event_entry_tag)new_event; |
| 283 | } |
| 284 | |
| 285 | |
| 286 | INLINE_EVENTS\ |
| 287 | (void) |
| 288 | event_queue_deschedule(event_queue *events, |
| 289 | event_entry_tag event_to_remove) |
| 290 | { |
| 291 | event_entry *to_remove = (event_entry*)event_to_remove; |
| 292 | ASSERT((events->time_from_event >= 0) == (events->queue != NULL)); |
| 293 | if (event_to_remove != NULL) { |
| 294 | event_entry *current; |
| 295 | event_entry **ptr_to_current; |
| 296 | for (ptr_to_current = &events->queue, current = *ptr_to_current; |
| 297 | current != NULL && current != to_remove; |
| 298 | ptr_to_current = ¤t->next, current = *ptr_to_current); |
| 299 | if (current == to_remove) { |
| 300 | *ptr_to_current = current->next; |
| 301 | TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", |
| 302 | (long)event_queue_time(events), |
| 303 | (long)event_to_remove, |
| 304 | (long)current->time_of_event, |
| 305 | (long)current->handler, |
| 306 | (long)current->data)); |
| 307 | free(current); |
| 308 | update_time_from_event(events); |
| 309 | } |
| 310 | else { |
| 311 | TRACE(trace_events, ("event descheduled at %ld - tag 0x%lx - not found\n", |
| 312 | (long)event_queue_time(events), |
| 313 | (long)event_to_remove)); |
| 314 | } |
| 315 | } |
| 316 | ASSERT((events->time_from_event >= 0) == (events->queue != NULL)); |
| 317 | } |
| 318 | |
| 319 | |
| 320 | |
| 321 | |
| 322 | INLINE_EVENTS\ |
| 323 | (int) |
| 324 | event_queue_tick(event_queue *events) |
| 325 | { |
| 326 | signed64 time_from_event; |
| 327 | |
| 328 | /* we should only be here when the previous tick has been fully processed */ |
| 329 | ASSERT(!events->processing); |
| 330 | |
| 331 | /* move any events that were queued by any signal handlers onto the |
| 332 | real event queue. BTW: When inlining, having this code here, |
| 333 | instead of in event_queue_process() causes GCC to put greater |
| 334 | weight on keeping the pointer EVENTS in a register. This, in |
| 335 | turn results in better code being output. */ |
| 336 | if (events->held != NULL) { |
| 337 | event_entry *held_events; |
| 338 | event_entry *curr_event; |
| 339 | |
| 340 | { |
| 341 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 342 | sigset_t old_mask; |
| 343 | sigset_t new_mask; |
| 344 | sigfillset(&new_mask); |
| 345 | /*-LOCK-*/ sigprocmask(SIG_SETMASK, &new_mask, &old_mask); |
| 346 | #endif |
| 347 | held_events = events->held; |
| 348 | events->held = NULL; |
| 349 | events->held_end = &events->held; |
| 350 | #if defined(HAVE_SIGPROCMASK) && defined(SIG_SETMASK) |
| 351 | /*-UNLOCK-*/ sigprocmask(SIG_SETMASK, &old_mask, NULL); |
| 352 | #endif |
| 353 | } |
| 354 | |
| 355 | do { |
| 356 | curr_event = held_events; |
| 357 | held_events = curr_event->next; |
| 358 | insert_event_entry(events, curr_event, curr_event->time_of_event); |
| 359 | } while (held_events != NULL); |
| 360 | } |
| 361 | |
| 362 | /* advance time, checking to see if we've reached time zero which |
| 363 | would indicate the time for the next event has arrived */ |
| 364 | time_from_event = events->time_from_event; |
| 365 | events->time_from_event = time_from_event - 1; |
| 366 | return time_from_event == 0; |
| 367 | } |
| 368 | |
| 369 | |
| 370 | |
| 371 | INLINE_EVENTS\ |
| 372 | (void) |
| 373 | event_queue_process(event_queue *events) |
| 374 | { |
| 375 | signed64 event_time = event_queue_time(events); |
| 376 | |
| 377 | ASSERT((events->time_from_event == -1 && events->queue != NULL) |
| 378 | || events->processing); /* something to do */ |
| 379 | |
| 380 | /* consume all events for this or earlier times. Be careful to |
| 381 | allow a new event to appear under our feet */ |
| 382 | events->processing = 1; |
| 383 | while (events->queue != NULL |
| 384 | && events->queue->time_of_event <= event_time) { |
| 385 | event_entry *to_do = events->queue; |
| 386 | event_handler *handler = to_do->handler; |
| 387 | void *data = to_do->data; |
| 388 | events->queue = to_do->next; |
| 389 | TRACE(trace_events, ("event issued at %ld - tag 0x%lx - time %ld, handler 0x%lx, data 0x%lx\n", |
| 390 | (long)event_time, |
| 391 | (long)to_do, |
| 392 | (long)to_do->time_of_event, |
| 393 | (long)handler, |
| 394 | (long)data)); |
| 395 | free(to_do); |
| 396 | /* Always re-compute the time to the next event so that HANDLER() |
| 397 | can safely insert new events into the queue. */ |
| 398 | update_time_from_event(events); |
| 399 | handler(data); |
| 400 | } |
| 401 | events->processing = 0; |
| 402 | |
| 403 | ASSERT(events->time_from_event > 0); |
| 404 | ASSERT(events->queue != NULL); /* always poll event */ |
| 405 | } |
| 406 | |
| 407 | |
| 408 | #endif /* _EVENTS_C_ */ |