glib/gmain.c

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * gmain.c: Main loop abstraction, timeouts, and idle functions
   5  * Copyright 1998 Owen Taylor
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Library General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public
  18  * License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 /*
  24  * MT safe
  25  */
  26
  27 #include "glib.h"
  28 #include <sys/types.h>
  29 #include <sys/time.h>
  30 #ifdef  GLIB_HAVE_SYS_POLL_H
  31 #include <sys/poll.h>
  32 #endif  /* GLIB_HAVE_SYS_POLL_H */
  33 #include <unistd.h>
  34 #include <errno.h>
  35 #include "config.h"
  36
  37 /* Types */
  38
  39 typedef struct _GIdleData GIdleData;
  40 typedef struct _GTimeoutData GTimeoutData;
  41 typedef struct _GSource GSource;
  42 typedef struct _GPollRec GPollRec;
  43
  44 typedef enum
  45 {
  46   G_SOURCE_READY = 1 << G_HOOK_FLAG_USER_SHIFT,
  47   G_SOURCE_CAN_RECURSE = 1 << (G_HOOK_FLAG_USER_SHIFT + 1)
  48 } GSourceFlags;
  49
  50 struct _GSource
  51 {
  52   GHook hook;
  53   gint priority;
  54   gpointer source_data;
  55 };
  56
  57 struct _GMainLoop
  58 {
  59   gboolean is_running;
  60 };
  61
  62 struct _GIdleData
  63 {
  64   GSourceFunc callback;
  65 };
  66
  67 struct _GTimeoutData
  68 {
  69   GTimeVal    expiration;
  70   gint        interval;
  71   GSourceFunc callback;
  72 };
  73
  74 struct _GPollRec
  75 {
  76   gint priority;
  77   GPollFD *fd;
  78   GPollRec *next;
  79 };
  80
  81 /* Forward declarations */
  82
  83 static void     g_main_poll               (gint      timeout,
  84                                            gboolean  use_priority,
  85                                            gint      priority);
  86 static void     g_main_add_poll_unlocked  (gint      priority,
  87                                            GPollFD  *fd);
  88
  89 static gboolean g_timeout_prepare      (gpointer  source_data,
  90                                         GTimeVal *current_time,
  91                                         gint     *timeout);
  92 static gboolean g_timeout_check        (gpointer  source_data,
  93                                         GTimeVal *current_time);
  94 static gboolean g_timeout_dispatch     (gpointer  source_data,
  95                                         GTimeVal *current_time,
  96                                         gpointer  user_data);
  97 static gboolean g_idle_prepare         (gpointer  source_data,
  98                                         GTimeVal *current_time,
  99                                         gint     *timeout);
 100 static gboolean g_idle_check           (gpointer  source_data,
 101                                         GTimeVal *current_time);
 102 static gboolean g_idle_dispatch        (gpointer  source_data,
 103                                         GTimeVal *current_time,
 104                                         gpointer  user_data);
 105
 106 /* Data */
 107
 108 static GSList *pending_dispatches = NULL;
 109 static GHookList source_list = { 0 };
 110
 111 /* The following lock is used for both the list of sources
 112  * and the list of poll records
 113  */
 114 G_LOCK_DECLARE_STATIC (main_loop);
 115
 116 static GSourceFuncs timeout_funcs = {
 117   g_timeout_prepare,
 118   g_timeout_check,
 119   g_timeout_dispatch,
 120   (GDestroyNotify)g_free
 121 };
 122
 123 static GSourceFuncs idle_funcs = {
 124   g_idle_prepare,
 125   g_idle_check,
 126   g_idle_dispatch,
 127   (GDestroyNotify)g_free
 128 };
 129
 130 static GPollRec *poll_records = NULL;
 131 static GPollRec *poll_free_list = NULL;
 132 static GMemChunk *poll_chunk;
 133 static guint n_poll_records = 0;
 134
 135 /* this pipe is used to wake up the main loop when a source is added.
 136  */
 137 static gint wake_up_pipe[2] = { -1, -1 };
 138 static GPollFD wake_up_rec;
 139 static gboolean poll_waiting = FALSE;
 140
 141 #ifdef HAVE_POLL
 142 static GPollFunc poll_func = (GPollFunc) poll;
 143 #else   /* !HAVE_POLL */
 144
 145 /* The following implementation of poll() comes from the GNU C Library.
 146  * Copyright (C) 1994, 1996, 1997 Free Software Foundation, Inc.
 147  */
 148
 149 #include <string.h> /* for bzero on BSD systems */
 150
 151 #ifdef HAVE_SYS_SELECT_H
 152 #include <sys/select.h>
 153 #endif /* HAVE_SYS_SELECT_H_ */
 154
 155 #ifndef NO_FD_SET
 156 #  define SELECT_MASK fd_set
 157 #else   /* !NO_FD_SET */
 158 #  ifndef _AIX
 159 typedef long fd_mask;
 160 #  endif
 161 #  if defined(_IBMR2)
 162 #    define SELECT_MASK void
 163 #  else
 164 #    define SELECT_MASK int
 165 #  endif
 166 #endif  /* !NO_FD_SET */
 167
 168 static gint
 169 g_poll (GPollFD *fds, guint nfds, gint timeout)
 170 {
 171   struct timeval tv;
 172   SELECT_MASK rset, wset, xset;
 173   GPollFD *f;
 174   int ready;
 175   int maxfd = 0;
 176
 177   FD_ZERO (&rset);
 178   FD_ZERO (&wset);
 179   FD_ZERO (&xset);
 180
 181   for (f = fds; f < &fds[nfds]; ++f)
 182     if (f->fd >= 0)
 183       {
 184         if (f->events & G_IO_IN)
 185           FD_SET (f->fd, &rset);
 186         if (f->events & G_IO_OUT)
 187           FD_SET (f->fd, &wset);
 188         if (f->events & G_IO_PRI)
 189           FD_SET (f->fd, &xset);
 190         if (f->fd > maxfd && (f->events & (G_IO_IN|G_IO_OUT|G_IO_PRI)))
 191           maxfd = f->fd;
 192       }
 193
 194   tv.tv_sec = timeout / 1000;
 195   tv.tv_usec = (timeout % 1000) * 1000;
 196
 197   ready = select (maxfd + 1, &rset, &wset, &xset,
 198                   timeout == -1 ? NULL : &tv);
 199   if (ready > 0)
 200     for (f = fds; f < &fds[nfds]; ++f)
 201       {
 202         f->revents = 0;
 203         if (f->fd >= 0)
 204           {
 205             if (FD_ISSET (f->fd, &rset))
 206               f->revents |= G_IO_IN;
 207             if (FD_ISSET (f->fd, &wset))
 208               f->revents |= G_IO_OUT;
 209             if (FD_ISSET (f->fd, &xset))
 210               f->revents |= G_IO_PRI;
 211           }
 212       }
 213
 214   return ready;
 215 }
 216 static GPollFunc poll_func = g_poll;
 217 #endif  /* !HAVE_POLL */
 218
 219 /* Hooks for adding to the main loop */
 220
 221 /* Use knowledge of insert_sorted algorithm here to make
 222  * sure we insert at the end of equal priority items
 223  */
 224 static gint
 225 g_source_compare (GHook *a,
 226                   GHook *b)
 227 {
 228   GSource *source_a = (GSource *)a;
 229   GSource *source_b = (GSource *)b;
 230
 231   return (source_a->priority < source_b->priority) ? -1 : 1;
 232 }
 233
 234 guint
 235 g_source_add (gint           priority,
 236               gboolean       can_recurse,
 237               GSourceFuncs  *funcs,
 238               gpointer       source_data,
 239               gpointer       user_data,
 240               GDestroyNotify notify)
 241 {
 242   guint return_val;
 243   GSource *source;
 244
 245   G_LOCK (main_loop);
 246
 247   if (!source_list.is_setup)
 248     g_hook_list_init (&source_list, sizeof(GSource));
 249
 250   source = (GSource *)g_hook_alloc (&source_list);
 251   source->priority = priority;
 252   source->source_data = source_data;
 253   source->hook.func = funcs;
 254   source->hook.data = user_data;
 255   source->hook.destroy = notify;
 256
 257   g_hook_insert_sorted (&source_list,
 258                         (GHook *)source,
 259                         g_source_compare);
 260
 261   if (can_recurse)
 262     source->hook.flags |= G_SOURCE_CAN_RECURSE;
 263
 264   return_val = source->hook.hook_id;
 265
 266   /* Now wake up the main loop if it is waiting in the poll() */
 267
 268   if (poll_waiting)
 269     {
 270       poll_waiting = FALSE;
 271       write (wake_up_pipe[1], "A", 1);
 272     }
 273
 274   G_UNLOCK (main_loop);
 275
 276   return return_val;
 277 }
 278
 279 void
 280 g_source_remove (guint tag)
 281 {
 282   GHook *hook;
 283
 284   G_LOCK (main_loop);
 285
 286   hook = g_hook_get (&source_list, tag);
 287   if (hook)
 288     {
 289       GSource *source = (GSource *)hook;
 290
 291       ((GSourceFuncs *) source->hook.func)->destroy (source->source_data);
 292       g_hook_destroy_link (&source_list, hook);
 293     }
 294
 295   G_UNLOCK (main_loop);
 296 }
 297
 298 void
 299 g_source_remove_by_user_data (gpointer user_data)
 300 {
 301   GHook *hook;
 302
 303   G_LOCK (main_loop);
 304
 305   hook = g_hook_find_data (&source_list, TRUE, user_data);
 306   if (hook)
 307     {
 308       GSource *source = (GSource *)hook;
 309
 310       ((GSourceFuncs *) source->hook.func)->destroy (source->source_data);
 311       g_hook_destroy_link (&source_list, hook);
 312     }
 313
 314   G_UNLOCK (main_loop);
 315 }
 316
 317 static gboolean
 318 g_source_find_source_data (GHook        *hook,
 319                            gpointer      data)
 320 {
 321   GSource *source = (GSource *)hook;
 322
 323   return (source->source_data == data);
 324 }
 325
 326 void
 327 g_source_remove_by_source_data (gpointer source_data)
 328 {
 329   GHook *hook;
 330
 331   G_LOCK (main_loop);
 332
 333   hook = g_hook_find (&source_list, TRUE,
 334                       g_source_find_source_data, source_data);
 335   if (hook)
 336     {
 337       GSource *source = (GSource *)hook;
 338
 339       ((GSourceFuncs *) source->hook.func)->destroy (source->source_data);
 340       g_hook_destroy_link (&source_list, hook);
 341     }
 342
 343   G_UNLOCK (main_loop);
 344 }
 345
 346 void
 347 g_get_current_time (GTimeVal *result)
 348 {
 349   g_return_if_fail (result != NULL);
 350
 351   gettimeofday ((struct timeval *) result, NULL);
 352 }
 353
 354 /* Running the main loop */
 355
 356 /* HOLDS: main_loop_lock */
 357 static void
 358 g_main_dispatch (GTimeVal *current_time)
 359 {
 360   while (pending_dispatches != NULL)
 361     {
 362       gboolean need_destroy;
 363       GSource *source = pending_dispatches->data;
 364       GSList *tmp_list;
 365
 366       tmp_list = pending_dispatches;
 367       pending_dispatches = g_slist_remove_link (pending_dispatches, pending_dispatches);
 368       g_slist_free_1 (tmp_list);
 369
 370       if (G_HOOK_IS_VALID (source))
 371         {
 372           gboolean was_in_call;
 373           gpointer hook_data = source->hook.data;
 374           gpointer source_data = source->source_data;
 375           gboolean (*dispatch) (gpointer,
 376                                 GTimeVal *,
 377                                 gpointer);
 378
 379           dispatch = ((GSourceFuncs *) source->hook.func)->dispatch;
 380
 381           was_in_call = G_HOOK_IN_CALL (source);
 382           source->hook.flags |= G_HOOK_FLAG_IN_CALL;
 383
 384           G_UNLOCK (main_loop);
 385           need_destroy = ! dispatch (source_data,
 386                                      current_time,
 387                                      hook_data);
 388           G_LOCK (main_loop);
 389
 390           if (!was_in_call)
 391             source->hook.flags &= ~G_HOOK_FLAG_IN_CALL;
 392
 393           if (need_destroy && G_HOOK_IS_VALID (source))
 394             {
 395               ((GSourceFuncs *) source->hook.func)->destroy (source->source_data);
 396               g_hook_destroy_link (&source_list, (GHook *) source);
 397             }
 398         }
 399
 400       g_hook_unref (&source_list, (GHook *)source);
 401     }
 402 }
 403
 404 /* g_main_iterate () runs a single iteration of the mainloop, or,
 405  * if !dispatch checks to see if any sources need dispatching.
 406  * basic algorithm for dispatch=TRUE:
 407  *
 408  * 1) while the list of currently pending sources is non-empty,
 409  *    we call (*dispatch) on those that are !IN_CALL or can_recurse,
 410  *    removing sources from the list after each returns.
 411  *    the return value of (*dispatch) determines whether the source
 412  *    itself is kept alive.
 413  *
 414  * 2) call (*prepare) for sources that are not yet SOURCE_READY and
 415  *    are !IN_CALL or can_recurse. a return value of TRUE determines
 416  *    that the source would like to be dispatched immediatedly, it
 417  *    is then flagged as SOURCE_READY.
 418  *
 419  * 3) poll with the pollfds from all sources at the priority of the
 420  *    first source flagged as SOURCE_READY. if there are any sources
 421  *    flagged as SOURCE_READY, we use a timeout of 0 or the minimum
 422  *    of all timouts otherwise.
 423  *
 424  * 4) for each source !IN_CALL or can_recurse, if SOURCE_READY or
 425  *    (*check) returns true, add the source to the pending list.
 426  *    once one source returns true, stop after checking all sources
 427  *    at that priority.
 428  *
 429  * 5) while the list of currently pending sources is non-empty,
 430  *    call (*dispatch) on each source, removing the source
 431  *    after the call.
 432  *
 433  */
 434 static gboolean
 435 g_main_iterate (gboolean block,
 436                 gboolean dispatch)
 437 {
 438   GHook *hook;
 439   GTimeVal current_time;
 440   gint n_ready = 0;
 441   gint current_priority = 0;
 442   gint timeout;
 443   gboolean retval = FALSE;
 444
 445   g_return_val_if_fail (!block || dispatch, FALSE);
 446
 447   g_get_current_time (&current_time);
 448
 449   G_LOCK (main_loop);
 450
 451   /* If recursing, finish up current dispatch, before starting over */
 452   if (pending_dispatches)
 453     {
 454       if (dispatch)
 455         g_main_dispatch (&current_time);
 456
 457       G_UNLOCK (main_loop);
 458
 459       return TRUE;
 460     }
 461
 462   /* Prepare all sources */
 463
 464   timeout = block ? -1 : 0;
 465
 466   hook = g_hook_first_valid (&source_list, TRUE);
 467   while (hook)
 468     {
 469       GSource *source = (GSource *)hook;
 470       GHook *tmp;
 471       gint source_timeout;
 472
 473       if ((n_ready > 0) && (source->priority > current_priority))
 474         break;
 475       if (G_HOOK_IN_CALL (hook) && !(hook->flags & G_SOURCE_CAN_RECURSE))
 476         {
 477           hook = g_hook_next_valid (hook, TRUE);
 478           continue;
 479         }
 480
 481       g_hook_ref (&source_list, hook);
 482
 483       if (hook->flags & G_SOURCE_READY ||
 484           ((GSourceFuncs *) hook->func)->prepare (source->source_data,
 485                                                   &current_time,
 486                                                   &source_timeout))
 487         {
 488           if (!dispatch)
 489             {
 490               hook->flags |= G_SOURCE_READY;
 491               g_hook_unref (&source_list, hook);
 492               G_UNLOCK (main_loop);
 493
 494               return TRUE;
 495             }
 496           else
 497             {
 498               hook->flags |= G_SOURCE_READY;
 499               n_ready++;
 500               current_priority = source->priority;
 501               timeout = 0;
 502             }
 503         }
 504
 505       if (source_timeout >= 0)
 506         {
 507           if (timeout < 0)
 508             timeout = source_timeout;
 509           else
 510             timeout = MIN (timeout, source_timeout);
 511         }
 512
 513       tmp = g_hook_next_valid (hook, TRUE);
 514
 515       g_hook_unref (&source_list, hook);
 516       hook = tmp;
 517     }
 518
 519   /* poll(), if necessary */
 520
 521   g_main_poll (timeout, n_ready > 0, current_priority);
 522
 523   /* Check to see what sources need to be dispatched */
 524
 525   n_ready = 0;
 526
 527   hook = g_hook_first_valid (&source_list, TRUE);
 528   while (hook)
 529     {
 530       GSource *source = (GSource *)hook;
 531       GHook *tmp;
 532
 533       if ((n_ready > 0) && (source->priority > current_priority))
 534         break;
 535       if (G_HOOK_IN_CALL (hook) && !(hook->flags & G_SOURCE_CAN_RECURSE))
 536         {
 537           hook = g_hook_next_valid (hook, TRUE);
 538           continue;
 539         }
 540
 541       g_hook_ref (&source_list, hook);
 542
 543       if (hook->flags & G_SOURCE_READY ||
 544           ((GSourceFuncs *) hook->func)->check (source->source_data,
 545                                                 &current_time))
 546         {
 547           if (dispatch)
 548             {
 549               hook->flags &= ~G_SOURCE_READY;
 550               g_hook_ref (&source_list, hook);
 551               pending_dispatches = g_slist_prepend (pending_dispatches, source);
 552               current_priority = source->priority;
 553               n_ready++;
 554             }
 555           else
 556             {
 557               g_hook_unref (&source_list, hook);
 558               G_UNLOCK (main_loop);
 559
 560               return TRUE;
 561             }
 562         }
 563
 564       tmp = g_hook_next_valid (hook, TRUE);
 565
 566       g_hook_unref (&source_list, hook);
 567       hook = tmp;
 568     }
 569
 570   /* Now invoke the callbacks */
 571
 572   if (pending_dispatches)
 573     {
 574       pending_dispatches = g_slist_reverse (pending_dispatches);
 575       g_main_dispatch (&current_time);
 576       retval = TRUE;
 577     }
 578
 579   G_UNLOCK (main_loop);
 580
 581   return retval;
 582 }
 583
 584 /* See if any events are pending
 585  */
 586 gboolean
 587 g_main_pending ()
 588 {
 589   return g_main_iterate (FALSE, FALSE);
 590 }
 591
 592 /* Run a single iteration of the mainloop. If block is FALSE,
 593  * will never block
 594  */
 595 gboolean
 596 g_main_iteration (gboolean block)
 597 {
 598   return g_main_iterate (block, TRUE);
 599 }
 600
 601 GMainLoop*
 602 g_main_new (gboolean is_running)
 603 {
 604   GMainLoop *loop;
 605
 606   loop = g_new0 (GMainLoop, 1);
 607   loop->is_running = is_running != FALSE;
 608
 609   return loop;
 610 }
 611
 612 void
 613 g_main_run (GMainLoop *loop)
 614 {
 615   g_return_if_fail (loop != NULL);
 616
 617   loop->is_running = TRUE;
 618   while (loop->is_running)
 619     g_main_iterate (TRUE, TRUE);
 620 }
 621
 622 void
 623 g_main_quit (GMainLoop *loop)
 624 {
 625   g_return_if_fail (loop != NULL);
 626
 627   loop->is_running = FALSE;
 628 }
 629
 630 void
 631 g_main_destroy (GMainLoop *loop)
 632 {
 633   g_return_if_fail (loop != NULL);
 634
 635   g_free (loop);
 636 }
 637
 638 gboolean
 639 g_main_is_running (GMainLoop *loop)
 640 {
 641   g_return_val_if_fail (loop != NULL, FALSE);
 642
 643   return loop->is_running;
 644 }
 645
 646 /* HOLDS: main_loop_lock */
 647 static void
 648 g_main_poll (gint     timeout,
 649              gboolean use_priority,
 650              gint     priority)
 651 {
 652   GPollFD *fd_array;
 653   GPollRec *pollrec;
 654
 655   gint i;
 656   gint npoll;
 657
 658   if (wake_up_pipe[0] < 0)
 659     {
 660       if (pipe (wake_up_pipe) < 0)
 661         g_error ("Cannot create pipe main loop wake-up: %s\n",
 662                  g_strerror (errno));
 663
 664       wake_up_rec.fd = wake_up_pipe[0];
 665       wake_up_rec.events = G_IO_IN;
 666       g_main_add_poll_unlocked (0, &wake_up_rec);
 667     }
 668
 669   fd_array = g_new (GPollFD, n_poll_records);
 670
 671   pollrec = poll_records;
 672   i = 0;
 673   while (pollrec && (!use_priority || priority >= pollrec->priority))
 674     {
 675       fd_array[i].fd = pollrec->fd->fd;
 676       fd_array[i].events = pollrec->fd->events;
 677       fd_array[i].revents = 0;
 678
 679       pollrec = pollrec->next;
 680       i++;
 681     }
 682
 683   poll_waiting = TRUE;
 684
 685   G_UNLOCK (main_loop);
 686   npoll = i;
 687   (*poll_func) (fd_array, npoll, timeout);
 688   G_LOCK (main_loop);
 689
 690   if (!poll_waiting)
 691     {
 692       gchar c;
 693       read (wake_up_pipe[0], &c, 1);
 694     }
 695   else
 696     poll_waiting = FALSE;
 697
 698   pollrec = poll_records;
 699   i = 0;
 700   while (i < npoll)
 701     {
 702       pollrec->fd->revents = fd_array[i].revents;
 703       pollrec = pollrec->next;
 704       i++;
 705     }
 706
 707   g_free (fd_array);
 708 }
 709
 710 void
 711 g_main_add_poll (GPollFD *fd,
 712                  gint     priority)
 713 {
 714   G_LOCK (main_loop);
 715   g_main_add_poll_unlocked (priority, fd);
 716   G_UNLOCK (main_loop);
 717 }
 718
 719 /* HOLDS: main_loop_lock */
 720 static void
 721 g_main_add_poll_unlocked (gint     priority,
 722                           GPollFD *fd)
 723 {
 724   GPollRec *lastrec, *pollrec, *newrec;
 725
 726   if (!poll_chunk)
 727     poll_chunk = g_mem_chunk_create (GPollRec, 32, G_ALLOC_ONLY);
 728
 729   if (poll_free_list)
 730     {
 731       newrec = poll_free_list;
 732       poll_free_list = newrec->next;
 733     }
 734   else
 735     newrec = g_chunk_new (GPollRec, poll_chunk);
 736
 737   newrec->fd = fd;
 738   newrec->priority = priority;
 739
 740   lastrec = NULL;
 741   pollrec = poll_records;
 742   while (pollrec && priority >= pollrec->priority)
 743     {
 744       lastrec = pollrec;
 745       pollrec = pollrec->next;
 746     }
 747
 748   if (lastrec)
 749     lastrec->next = newrec;
 750   else
 751     poll_records = newrec;
 752
 753   newrec->next = pollrec;
 754
 755   n_poll_records++;
 756 }
 757
 758 void
 759 g_main_remove_poll (GPollFD *fd)
 760 {
 761   GPollRec *pollrec, *lastrec;
 762
 763   G_LOCK (main_loop);
 764
 765   lastrec = NULL;
 766   pollrec = poll_records;
 767
 768   while (pollrec)
 769     {
 770       if (pollrec->fd == fd)
 771         {
 772           if (lastrec != NULL)
 773             lastrec->next = pollrec->next;
 774           else
 775             poll_records = pollrec->next;
 776
 777           pollrec->next = poll_free_list;
 778           poll_free_list = pollrec;
 779
 780           n_poll_records--;
 781           break;
 782         }
 783       lastrec = pollrec;
 784       pollrec = pollrec->next;
 785     }
 786
 787   G_UNLOCK (main_loop);
 788 }
 789
 790 void
 791 g_main_set_poll_func (GPollFunc func)
 792 {
 793   if (func)
 794     poll_func = func;
 795   else
 796 #ifdef HAVE_POLL
 797     poll_func = (GPollFunc)poll;
 798 #else
 799     poll_func = (GPollFunc)g_poll;
 800 #endif
 801 }
 802
 803 /* Timeouts */
 804
 805 static gboolean
 806 g_timeout_prepare  (gpointer source_data,
 807                     GTimeVal *current_time,
 808                     gint    *timeout)
 809 {
 810   glong msec;
 811   GTimeoutData *data = source_data;
 812
 813   msec = (data->expiration.tv_sec  - current_time->tv_sec) * 1000 +
 814          (data->expiration.tv_usec - current_time->tv_usec) / 1000;
 815
 816   *timeout = (msec <= 0) ? 0 : msec;
 817
 818   return (msec <= 0);
 819 }
 820
 821 static gboolean
 822 g_timeout_check    (gpointer source_data,
 823                     GTimeVal *current_time)
 824 {
 825   GTimeoutData *data = source_data;
 826
 827   return (data->expiration.tv_sec < current_time->tv_sec) ||
 828          ((data->expiration.tv_sec == current_time->tv_sec) &&
 829           (data->expiration.tv_usec <= current_time->tv_usec));
 830 }
 831
 832 static gboolean
 833 g_timeout_dispatch (gpointer source_data,
 834                     GTimeVal *current_time,
 835                     gpointer user_data)
 836 {
 837   GTimeoutData *data = source_data;
 838
 839   if (data->callback(user_data))
 840     {
 841       guint seconds = data->interval / 1000;
 842       guint msecs = data->interval - seconds * 1000;
 843
 844       data->expiration.tv_sec = current_time->tv_sec + seconds;
 845       data->expiration.tv_usec = current_time->tv_usec + msecs * 1000;
 846       if (data->expiration.tv_usec >= 1000000)
 847         {
 848           data->expiration.tv_usec -= 1000000;
 849           data->expiration.tv_sec++;
 850         }
 851       return TRUE;
 852     }
 853   else
 854     return FALSE;
 855 }
 856
 857 guint
 858 g_timeout_add_full (gint           priority,
 859                     guint          interval,
 860                     GSourceFunc    function,
 861                     gpointer       data,
 862                     GDestroyNotify notify)
 863 {
 864   guint seconds;
 865   guint msecs;
 866   GTimeoutData *timeout_data = g_new (GTimeoutData, 1);
 867
 868   timeout_data->interval = interval;
 869   timeout_data->callback = function;
 870   g_get_current_time (&timeout_data->expiration);
 871
 872   seconds = timeout_data->interval / 1000;
 873   msecs = timeout_data->interval - seconds * 1000;
 874
 875   timeout_data->expiration.tv_sec += seconds;
 876   timeout_data->expiration.tv_usec += msecs * 1000;
 877   if (timeout_data->expiration.tv_usec >= 1000000)
 878     {
 879       timeout_data->expiration.tv_usec -= 1000000;
 880       timeout_data->expiration.tv_sec++;
 881     }
 882
 883   return g_source_add (priority, FALSE, &timeout_funcs, timeout_data, data, notify);
 884 }
 885
 886 guint
 887 g_timeout_add (guint32        interval,
 888                GSourceFunc    function,
 889                gpointer       data)
 890 {
 891   return g_timeout_add_full (G_PRIORITY_DEFAULT,
 892                              interval, function, data, NULL);
 893 }
 894
 895 /* Idle functions */
 896
 897 static gboolean
 898 g_idle_prepare  (gpointer source_data,
 899                  GTimeVal *current_time,
 900                  gint     *timeout)
 901 {
 902   timeout = 0;
 903   return TRUE;
 904 }
 905
 906 static gboolean
 907 g_idle_check    (gpointer  source_data,
 908                  GTimeVal *current_time)
 909 {
 910   return TRUE;
 911 }
 912
 913 static gboolean
 914 g_idle_dispatch (gpointer source_data,
 915                  GTimeVal *current_time,
 916                  gpointer user_data)
 917 {
 918   GIdleData *data = source_data;
 919
 920   return (*data->callback)(user_data);
 921 }
 922
 923 guint
 924 g_idle_add_full (gint          priority,
 925                  GSourceFunc    function,
 926                  gpointer       data,
 927                  GDestroyNotify notify)
 928 {
 929   GIdleData *idle_data = g_new (GIdleData, 1);
 930
 931   idle_data->callback = function;
 932
 933   return g_source_add (priority, FALSE, &idle_funcs, idle_data, data, notify);
 934 }
 935
 936 guint
 937 g_idle_add (GSourceFunc    function,
 938             gpointer       data)
 939 {
 940   return g_idle_add_full (G_PRIORITY_DEFAULT_IDLE, function, data, NULL);
 941 }