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dbus-mainloop.c

00001 /* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
00002 /* dbus-mainloop.c  Main loop utility
00003  *
00004  * Copyright (C) 2003, 2004  Red Hat, Inc.
00005  *
00006  * Licensed under the Academic Free License version 2.1
00007  * 
00008  * This program is free software; you can redistribute it and/or modify
00009  * it under the terms of the GNU General Public License as published by
00010  * the Free Software Foundation; either version 2 of the License, or
00011  * (at your option) any later version.
00012  *
00013  * This program is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00016  * GNU General Public License for more details.
00017  * 
00018  * You should have received a copy of the GNU General Public License
00019  * along with this program; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
00021  *
00022  */
00023 
00024 #include <config.h>
00025 #include "dbus-mainloop.h"
00026 
00027 #ifndef DOXYGEN_SHOULD_SKIP_THIS
00028 
00029 #include <dbus/dbus-list.h>
00030 #include <dbus/dbus-sysdeps.h>
00031 
00032 #define MAINLOOP_SPEW 0
00033 
00034 #if MAINLOOP_SPEW
00035 #ifdef DBUS_ENABLE_VERBOSE_MODE
00036 static const char*
00037 watch_flags_to_string (int flags)
00038 {
00039   const char *watch_type;
00040 
00041   if ((flags & DBUS_WATCH_READABLE) &&
00042       (flags & DBUS_WATCH_WRITABLE))
00043     watch_type = "readwrite";
00044   else if (flags & DBUS_WATCH_READABLE)
00045     watch_type = "read";
00046   else if (flags & DBUS_WATCH_WRITABLE)
00047     watch_type = "write";
00048   else
00049     watch_type = "not read or write";
00050   return watch_type;
00051 }
00052 #endif /* DBUS_ENABLE_VERBOSE_MODE */
00053 #endif /* MAINLOOP_SPEW */
00054 
00055 struct DBusLoop
00056 {
00057   int refcount;
00058   DBusList *callbacks;
00059   int callback_list_serial;
00060   int watch_count;
00061   int timeout_count;
00062   int depth; 
00063   DBusList *need_dispatch;
00064 };
00065 
00066 typedef enum
00067 {
00068   CALLBACK_WATCH,
00069   CALLBACK_TIMEOUT
00070 } CallbackType;
00071 
00072 typedef struct
00073 {
00074   int refcount;
00075   CallbackType type;
00076   void *data;
00077   DBusFreeFunction free_data_func;
00078 } Callback;
00079 
00080 typedef struct
00081 {
00082   Callback callback;
00083   DBusWatchFunction function;
00084   DBusWatch *watch;
00085   /* last watch handle failed due to OOM */
00086   unsigned int last_iteration_oom : 1;
00087 } WatchCallback;
00088 
00089 typedef struct
00090 {
00091   Callback callback;
00092   DBusTimeout *timeout;
00093   DBusTimeoutFunction function;
00094   unsigned long last_tv_sec;
00095   unsigned long last_tv_usec;
00096 } TimeoutCallback;
00097 
00098 #define WATCH_CALLBACK(callback)   ((WatchCallback*)callback)
00099 #define TIMEOUT_CALLBACK(callback) ((TimeoutCallback*)callback)
00100 
00101 static WatchCallback*
00102 watch_callback_new (DBusWatch         *watch,
00103                     DBusWatchFunction  function,
00104                     void              *data,
00105                     DBusFreeFunction   free_data_func)
00106 {
00107   WatchCallback *cb;
00108 
00109   cb = dbus_new (WatchCallback, 1);
00110   if (cb == NULL)
00111     return NULL;
00112 
00113   cb->watch = watch;
00114   cb->function = function;
00115   cb->last_iteration_oom = FALSE;
00116   cb->callback.refcount = 1;
00117   cb->callback.type = CALLBACK_WATCH;
00118   cb->callback.data = data;
00119   cb->callback.free_data_func = free_data_func;
00120   
00121   return cb;
00122 }
00123 
00124 static TimeoutCallback*
00125 timeout_callback_new (DBusTimeout         *timeout,
00126                       DBusTimeoutFunction  function,
00127                       void                *data,
00128                       DBusFreeFunction     free_data_func)
00129 {
00130   TimeoutCallback *cb;
00131 
00132   cb = dbus_new (TimeoutCallback, 1);
00133   if (cb == NULL)
00134     return NULL;
00135 
00136   cb->timeout = timeout;
00137   cb->function = function;
00138   _dbus_get_current_time (&cb->last_tv_sec,
00139                           &cb->last_tv_usec);
00140   cb->callback.refcount = 1;    
00141   cb->callback.type = CALLBACK_TIMEOUT;
00142   cb->callback.data = data;
00143   cb->callback.free_data_func = free_data_func;
00144   
00145   return cb;
00146 }
00147 
00148 static Callback * 
00149 callback_ref (Callback *cb)
00150 {
00151   _dbus_assert (cb->refcount > 0);
00152   
00153   cb->refcount += 1;
00154 
00155   return cb;
00156 }
00157 
00158 static void
00159 callback_unref (Callback *cb)
00160 {
00161   _dbus_assert (cb->refcount > 0);
00162 
00163   cb->refcount -= 1;
00164 
00165   if (cb->refcount == 0)
00166     {
00167       if (cb->free_data_func)
00168         (* cb->free_data_func) (cb->data);
00169       
00170       dbus_free (cb);
00171     }
00172 }
00173 
00174 static dbus_bool_t
00175 add_callback (DBusLoop  *loop,
00176               Callback *cb)
00177 {
00178   if (!_dbus_list_append (&loop->callbacks, cb))
00179     return FALSE;
00180 
00181   loop->callback_list_serial += 1;
00182 
00183   switch (cb->type)
00184     {
00185     case CALLBACK_WATCH:
00186       loop->watch_count += 1;
00187       break;
00188     case CALLBACK_TIMEOUT:
00189       loop->timeout_count += 1;
00190       break;
00191     }
00192   
00193   return TRUE;
00194 }
00195 
00196 static void
00197 remove_callback (DBusLoop  *loop,
00198                  DBusList *link)
00199 {
00200   Callback *cb = link->data;
00201   
00202   switch (cb->type)
00203     {
00204     case CALLBACK_WATCH:
00205       loop->watch_count -= 1;
00206       break;
00207     case CALLBACK_TIMEOUT:
00208       loop->timeout_count -= 1;
00209       break;
00210     }
00211   
00212   callback_unref (cb);
00213   _dbus_list_remove_link (&loop->callbacks, link);
00214   loop->callback_list_serial += 1;
00215 }
00216 
00217 DBusLoop*
00218 _dbus_loop_new (void)
00219 {
00220   DBusLoop *loop;
00221 
00222   loop = dbus_new0 (DBusLoop, 1);
00223   if (loop == NULL)
00224     return NULL;
00225 
00226   loop->refcount = 1;
00227   
00228   return loop;
00229 }
00230 
00231 DBusLoop *
00232 _dbus_loop_ref (DBusLoop *loop)
00233 {
00234   _dbus_assert (loop != NULL);
00235   _dbus_assert (loop->refcount > 0);
00236 
00237   loop->refcount += 1;
00238 
00239   return loop;
00240 }
00241 
00242 void
00243 _dbus_loop_unref (DBusLoop *loop)
00244 {
00245   _dbus_assert (loop != NULL);
00246   _dbus_assert (loop->refcount > 0);
00247 
00248   loop->refcount -= 1;
00249   if (loop->refcount == 0)
00250     {
00251       while (loop->need_dispatch)
00252         {
00253           DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
00254 
00255           dbus_connection_unref (connection);
00256         }
00257       
00258       dbus_free (loop);
00259     }
00260 }
00261 
00262 dbus_bool_t
00263 _dbus_loop_add_watch (DBusLoop          *loop,
00264                       DBusWatch        *watch,
00265                       DBusWatchFunction  function,
00266                       void             *data,
00267                       DBusFreeFunction  free_data_func)
00268 {
00269   WatchCallback *wcb;
00270 
00271   wcb = watch_callback_new (watch, function, data, free_data_func);
00272   if (wcb == NULL)
00273     return FALSE;
00274 
00275   if (!add_callback (loop, (Callback*) wcb))
00276     {
00277       wcb->callback.free_data_func = NULL; /* don't want to have this side effect */
00278       callback_unref ((Callback*) wcb);
00279       return FALSE;
00280     }
00281   
00282   return TRUE;
00283 }
00284 
00285 void
00286 _dbus_loop_remove_watch (DBusLoop          *loop,
00287                          DBusWatch        *watch,
00288                          DBusWatchFunction  function,
00289                          void             *data)
00290 {
00291   DBusList *link;
00292   
00293   link = _dbus_list_get_first_link (&loop->callbacks);
00294   while (link != NULL)
00295     {
00296       DBusList *next = _dbus_list_get_next_link (&loop->callbacks, link);
00297       Callback *this = link->data;
00298 
00299       if (this->type == CALLBACK_WATCH &&
00300           WATCH_CALLBACK (this)->watch == watch &&
00301           this->data == data &&
00302           WATCH_CALLBACK (this)->function == function)
00303         {
00304           remove_callback (loop, link);
00305           
00306           return;
00307         }
00308       
00309       link = next;
00310     }
00311 
00312   _dbus_warn ("could not find watch %p function %p data %p to remove\n",
00313               watch, (void *)function, data);
00314 }
00315 
00316 dbus_bool_t
00317 _dbus_loop_add_timeout (DBusLoop            *loop,
00318                         DBusTimeout        *timeout,
00319                         DBusTimeoutFunction  function,
00320                         void               *data,
00321                         DBusFreeFunction    free_data_func)
00322 {
00323   TimeoutCallback *tcb;
00324 
00325   tcb = timeout_callback_new (timeout, function, data, free_data_func);
00326   if (tcb == NULL)
00327     return FALSE;
00328 
00329   if (!add_callback (loop, (Callback*) tcb))
00330     {
00331       tcb->callback.free_data_func = NULL; /* don't want to have this side effect */
00332       callback_unref ((Callback*) tcb);
00333       return FALSE;
00334     }
00335   
00336   return TRUE;
00337 }
00338 
00339 void
00340 _dbus_loop_remove_timeout (DBusLoop            *loop,
00341                            DBusTimeout        *timeout,
00342                            DBusTimeoutFunction  function,
00343                            void               *data)
00344 {
00345   DBusList *link;
00346   
00347   link = _dbus_list_get_first_link (&loop->callbacks);
00348   while (link != NULL)
00349     {
00350       DBusList *next = _dbus_list_get_next_link (&loop->callbacks, link);
00351       Callback *this = link->data;
00352 
00353       if (this->type == CALLBACK_TIMEOUT &&
00354           TIMEOUT_CALLBACK (this)->timeout == timeout &&
00355           this->data == data &&
00356           TIMEOUT_CALLBACK (this)->function == function)
00357         {
00358           remove_callback (loop, link);
00359           
00360           return;
00361         }
00362       
00363       link = next;
00364     }
00365 
00366   _dbus_warn ("could not find timeout %p function %p data %p to remove\n",
00367               timeout, (void *)function, data);
00368 }
00369 
00370 /* Convolutions from GLib, there really must be a better way
00371  * to do this.
00372  */
00373 static dbus_bool_t
00374 check_timeout (unsigned long    tv_sec,
00375                unsigned long    tv_usec,
00376                TimeoutCallback *tcb,
00377                int             *timeout)
00378 {
00379   long sec_remaining;
00380   long msec_remaining;
00381   unsigned long expiration_tv_sec;
00382   unsigned long expiration_tv_usec;
00383   long interval_seconds;
00384   long interval_milliseconds;
00385   int interval;
00386 
00387   /* I'm pretty sure this function could suck (a lot) less */
00388   
00389   interval = dbus_timeout_get_interval (tcb->timeout);
00390   
00391   interval_seconds = interval / 1000L;
00392   interval_milliseconds = interval % 1000L;
00393   
00394   expiration_tv_sec = tcb->last_tv_sec + interval_seconds;
00395   expiration_tv_usec = tcb->last_tv_usec + interval_milliseconds * 1000;
00396   if (expiration_tv_usec >= 1000000)
00397     {
00398       expiration_tv_usec -= 1000000;
00399       expiration_tv_sec += 1;
00400     }
00401   
00402   sec_remaining = expiration_tv_sec - tv_sec;
00403   /* need to force this to be signed, as it is intended to sometimes
00404    * produce a negative result
00405    */
00406   msec_remaining = ((long) expiration_tv_usec - (long) tv_usec) / 1000L;
00407 
00408 #if MAINLOOP_SPEW
00409   _dbus_verbose ("Interval is %ld seconds %ld msecs\n",
00410                  interval_seconds,
00411                  interval_milliseconds);
00412   _dbus_verbose ("Now is  %lu seconds %lu usecs\n",
00413                  tv_sec, tv_usec);
00414   _dbus_verbose ("Last is %lu seconds %lu usecs\n",
00415                  tcb->last_tv_sec, tcb->last_tv_usec);
00416   _dbus_verbose ("Exp is  %lu seconds %lu usecs\n",
00417                  expiration_tv_sec, expiration_tv_usec);
00418   _dbus_verbose ("Pre-correction, sec_remaining %ld msec_remaining %ld\n",
00419                  sec_remaining, msec_remaining);
00420 #endif
00421   
00422   /* We do the following in a rather convoluted fashion to deal with
00423    * the fact that we don't have an integral type big enough to hold
00424    * the difference of two timevals in milliseconds.
00425    */
00426   if (sec_remaining < 0 || (sec_remaining == 0 && msec_remaining < 0))
00427     {
00428       *timeout = 0;
00429     }
00430   else
00431     {
00432       if (msec_remaining < 0)
00433         {
00434           msec_remaining += 1000;
00435           sec_remaining -= 1;
00436         }
00437 
00438       if (sec_remaining > (_DBUS_INT_MAX / 1000) ||
00439           msec_remaining > _DBUS_INT_MAX)
00440         *timeout = _DBUS_INT_MAX;
00441       else
00442         *timeout = sec_remaining * 1000 + msec_remaining;        
00443     }
00444 
00445   if (*timeout > interval)
00446     {
00447       /* This indicates that the system clock probably moved backward */
00448       _dbus_verbose ("System clock set backward! Resetting timeout.\n");
00449       
00450       tcb->last_tv_sec = tv_sec;
00451       tcb->last_tv_usec = tv_usec;
00452 
00453       *timeout = interval;
00454     }
00455   
00456 #if MAINLOOP_SPEW
00457   _dbus_verbose ("  timeout expires in %d milliseconds\n", *timeout);
00458 #endif
00459   
00460   return *timeout == 0;
00461 }
00462 
00463 dbus_bool_t
00464 _dbus_loop_dispatch (DBusLoop *loop)
00465 {
00466 
00467 #if MAINLOOP_SPEW
00468   _dbus_verbose ("  %d connections to dispatch\n", _dbus_list_get_length (&loop->need_dispatch));
00469 #endif
00470   
00471   if (loop->need_dispatch == NULL)
00472     return FALSE;
00473   
00474  next:
00475   while (loop->need_dispatch != NULL)
00476     {
00477       DBusConnection *connection = _dbus_list_pop_first (&loop->need_dispatch);
00478       
00479       while (TRUE)
00480         {
00481           DBusDispatchStatus status;
00482           
00483           status = dbus_connection_dispatch (connection);
00484 
00485           if (status == DBUS_DISPATCH_COMPLETE)
00486             {
00487               dbus_connection_unref (connection);
00488               goto next;
00489             }
00490           else
00491             {
00492               if (status == DBUS_DISPATCH_NEED_MEMORY)
00493                 _dbus_wait_for_memory ();
00494             }
00495         }
00496     }
00497 
00498   return TRUE;
00499 }
00500 
00501 dbus_bool_t
00502 _dbus_loop_queue_dispatch (DBusLoop       *loop,
00503                            DBusConnection *connection)
00504 {
00505   if (_dbus_list_append (&loop->need_dispatch, connection))
00506     {
00507       dbus_connection_ref (connection);
00508       return TRUE;
00509     }
00510   else
00511     return FALSE;
00512 }
00513 
00514 /* Returns TRUE if we invoked any timeouts or have ready file
00515  * descriptors, which is just used in test code as a debug hack
00516  */
00517 
00518 dbus_bool_t
00519 _dbus_loop_iterate (DBusLoop     *loop,
00520                     dbus_bool_t   block)
00521 {  
00522 #define N_STACK_DESCRIPTORS 64
00523   dbus_bool_t retval;
00524   DBusPollFD *fds;
00525   DBusPollFD stack_fds[N_STACK_DESCRIPTORS];
00526   int n_fds;
00527   WatchCallback **watches_for_fds;
00528   WatchCallback *stack_watches_for_fds[N_STACK_DESCRIPTORS];
00529   int i;
00530   DBusList *link;
00531   int n_ready;
00532   int initial_serial;
00533   long timeout;
00534   dbus_bool_t oom_watch_pending;
00535   int orig_depth;
00536   
00537   retval = FALSE;      
00538 
00539   fds = NULL;
00540   watches_for_fds = NULL;
00541   n_fds = 0;
00542   oom_watch_pending = FALSE;
00543   orig_depth = loop->depth;
00544   
00545 #if MAINLOOP_SPEW
00546   _dbus_verbose ("Iteration block=%d depth=%d timeout_count=%d watch_count=%d\n",
00547                  block, loop->depth, loop->timeout_count, loop->watch_count);
00548 #endif
00549   
00550   if (loop->callbacks == NULL)
00551     goto next_iteration;
00552 
00553   if (loop->watch_count > N_STACK_DESCRIPTORS)
00554     {
00555       fds = dbus_new0 (DBusPollFD, loop->watch_count);
00556       
00557       while (fds == NULL)
00558         {
00559           _dbus_wait_for_memory ();
00560           fds = dbus_new0 (DBusPollFD, loop->watch_count);
00561         }
00562       
00563       watches_for_fds = dbus_new (WatchCallback*, loop->watch_count);
00564       while (watches_for_fds == NULL)
00565         {
00566           _dbus_wait_for_memory ();
00567           watches_for_fds = dbus_new (WatchCallback*, loop->watch_count);
00568         }
00569     }
00570   else
00571     {      
00572       fds = stack_fds;
00573       watches_for_fds = stack_watches_for_fds;
00574     }
00575 
00576   /* fill our array of fds and watches */
00577   n_fds = 0;
00578   link = _dbus_list_get_first_link (&loop->callbacks);
00579   while (link != NULL)
00580     {
00581       DBusList *next = _dbus_list_get_next_link (&loop->callbacks, link);
00582       Callback *cb = link->data;
00583       if (cb->type == CALLBACK_WATCH)
00584         {
00585           unsigned int flags;
00586           WatchCallback *wcb = WATCH_CALLBACK (cb);
00587 
00588           if (wcb->last_iteration_oom)
00589             {
00590               /* we skip this one this time, but reenable it next time,
00591                * and have a timeout on this iteration
00592                */
00593               wcb->last_iteration_oom = FALSE;
00594               oom_watch_pending = TRUE;
00595               
00596               retval = TRUE; /* return TRUE here to keep the loop going,
00597                               * since we don't know the watch is inactive
00598                               */
00599 
00600 #if MAINLOOP_SPEW
00601               _dbus_verbose ("  skipping watch on fd %d as it was out of memory last time\n",
00602                              dbus_watch_get_socket (wcb->watch));
00603 #endif
00604             }
00605           else if (dbus_watch_get_enabled (wcb->watch))
00606             {
00607               watches_for_fds[n_fds] = wcb;
00608 
00609               callback_ref (cb);
00610                   
00611               flags = dbus_watch_get_flags (wcb->watch);
00612                   
00613               fds[n_fds].fd = dbus_watch_get_socket (wcb->watch);
00614               fds[n_fds].revents = 0;
00615               fds[n_fds].events = 0;
00616               if (flags & DBUS_WATCH_READABLE)
00617                 fds[n_fds].events |= _DBUS_POLLIN;
00618               if (flags & DBUS_WATCH_WRITABLE)
00619                 fds[n_fds].events |= _DBUS_POLLOUT;
00620 
00621 #if MAINLOOP_SPEW
00622               _dbus_verbose ("  polling watch on fd %d  %s\n",
00623                              fds[n_fds].fd, watch_flags_to_string (flags));
00624 #endif
00625 
00626               n_fds += 1;
00627             }
00628           else
00629             {
00630 #if MAINLOOP_SPEW
00631               _dbus_verbose ("  skipping disabled watch on fd %d  %s\n",
00632                              dbus_watch_get_socket (wcb->watch),
00633                              watch_flags_to_string (dbus_watch_get_flags (wcb->watch)));
00634 #endif
00635             }
00636         }
00637               
00638       link = next;
00639     }
00640   
00641   timeout = -1;
00642   if (loop->timeout_count > 0)
00643     {
00644       unsigned long tv_sec;
00645       unsigned long tv_usec;
00646       
00647       _dbus_get_current_time (&tv_sec, &tv_usec);
00648           
00649       link = _dbus_list_get_first_link (&loop->callbacks);
00650       while (link != NULL)
00651         {
00652           DBusList *next = _dbus_list_get_next_link (&loop->callbacks, link);
00653           Callback *cb = link->data;
00654 
00655           if (cb->type == CALLBACK_TIMEOUT &&
00656               dbus_timeout_get_enabled (TIMEOUT_CALLBACK (cb)->timeout))
00657             {
00658               TimeoutCallback *tcb = TIMEOUT_CALLBACK (cb);
00659               int msecs_remaining;
00660 
00661               check_timeout (tv_sec, tv_usec, tcb, &msecs_remaining);
00662 
00663               if (timeout < 0)
00664                 timeout = msecs_remaining;
00665               else
00666                 timeout = MIN (msecs_remaining, timeout);
00667 
00668 #if MAINLOOP_SPEW
00669               _dbus_verbose ("  timeout added, %d remaining, aggregate timeout %ld\n",
00670                              msecs_remaining, timeout);
00671 #endif
00672               
00673               _dbus_assert (timeout >= 0);
00674                   
00675               if (timeout == 0)
00676                 break; /* it's not going to get shorter... */
00677             }
00678 #if MAINLOOP_SPEW
00679           else if (cb->type == CALLBACK_TIMEOUT)
00680             {
00681               _dbus_verbose ("  skipping disabled timeout\n");
00682             }
00683 #endif
00684           
00685           link = next;
00686         }
00687     }
00688 
00689   /* Never block if we have stuff to dispatch */
00690   if (!block || loop->need_dispatch != NULL)
00691     {
00692       timeout = 0;
00693 #if MAINLOOP_SPEW
00694       _dbus_verbose ("  timeout is 0 as we aren't blocking\n");
00695 #endif
00696     }
00697 
00698   /* if a watch is OOM, don't wait longer than the OOM
00699    * wait to re-enable it
00700    */
00701   if (oom_watch_pending)
00702     timeout = MIN (timeout, _dbus_get_oom_wait ());
00703 
00704 #if MAINLOOP_SPEW
00705   _dbus_verbose ("  polling on %d descriptors timeout %ld\n", n_fds, timeout);
00706 #endif
00707   
00708   n_ready = _dbus_poll (fds, n_fds, timeout);
00709 
00710   initial_serial = loop->callback_list_serial;
00711 
00712   if (loop->timeout_count > 0)
00713     {
00714       unsigned long tv_sec;
00715       unsigned long tv_usec;
00716 
00717       _dbus_get_current_time (&tv_sec, &tv_usec);
00718 
00719       /* It'd be nice to avoid this O(n) thingy here */
00720       link = _dbus_list_get_first_link (&loop->callbacks);
00721       while (link != NULL)
00722         {
00723           DBusList *next = _dbus_list_get_next_link (&loop->callbacks, link);
00724           Callback *cb = link->data;
00725 
00726           if (initial_serial != loop->callback_list_serial)
00727             goto next_iteration;
00728 
00729           if (loop->depth != orig_depth)
00730             goto next_iteration;
00731               
00732           if (cb->type == CALLBACK_TIMEOUT &&
00733               dbus_timeout_get_enabled (TIMEOUT_CALLBACK (cb)->timeout))
00734             {
00735               TimeoutCallback *tcb = TIMEOUT_CALLBACK (cb);
00736               int msecs_remaining;
00737               
00738               if (check_timeout (tv_sec, tv_usec,
00739                                  tcb, &msecs_remaining))
00740                 {
00741                   /* Save last callback time and fire this timeout */
00742                   tcb->last_tv_sec = tv_sec;
00743                   tcb->last_tv_usec = tv_usec;
00744 
00745 #if MAINLOOP_SPEW
00746                   _dbus_verbose ("  invoking timeout\n");
00747 #endif
00748                   
00749                   (* tcb->function) (tcb->timeout,
00750                                      cb->data);
00751 
00752                   retval = TRUE;
00753                 }
00754               else
00755                 {
00756 #if MAINLOOP_SPEW
00757                   _dbus_verbose ("  timeout has not expired\n");
00758 #endif
00759                 }
00760             }
00761 #if MAINLOOP_SPEW
00762           else if (cb->type == CALLBACK_TIMEOUT)
00763             {
00764               _dbus_verbose ("  skipping invocation of disabled timeout\n");
00765             }
00766 #endif
00767 
00768           link = next;
00769         }
00770     }
00771       
00772   if (n_ready > 0)
00773     {
00774       i = 0;
00775       while (i < n_fds)
00776         {
00777           /* FIXME I think this "restart if we change the watches"
00778            * approach could result in starving watches
00779            * toward the end of the list.
00780            */
00781           if (initial_serial != loop->callback_list_serial)
00782             goto next_iteration;
00783 
00784           if (loop->depth != orig_depth)
00785             goto next_iteration;
00786 
00787           if (fds[i].revents != 0)
00788             {
00789               WatchCallback *wcb;
00790               unsigned int condition;
00791                   
00792               wcb = watches_for_fds[i];
00793               
00794               condition = 0;
00795               if (fds[i].revents & _DBUS_POLLIN)
00796                 condition |= DBUS_WATCH_READABLE;
00797               if (fds[i].revents & _DBUS_POLLOUT)
00798                 condition |= DBUS_WATCH_WRITABLE;
00799               if (fds[i].revents & _DBUS_POLLHUP)
00800                 condition |= DBUS_WATCH_HANGUP;
00801               if (fds[i].revents & _DBUS_POLLERR)
00802                 condition |= DBUS_WATCH_ERROR;
00803 
00804               /* condition may still be 0 if we got some
00805                * weird POLLFOO thing like POLLWRBAND
00806                */
00807                   
00808               if (condition != 0 &&
00809                   dbus_watch_get_enabled (wcb->watch))
00810                 {
00811                   if (!(* wcb->function) (wcb->watch,
00812                                           condition,
00813                                           ((Callback*)wcb)->data))
00814                     wcb->last_iteration_oom = TRUE;
00815 
00816 #if MAINLOOP_SPEW
00817                   _dbus_verbose ("  Invoked watch, oom = %d\n",
00818                                  wcb->last_iteration_oom);
00819 #endif
00820                   
00821                   retval = TRUE;
00822                 }
00823             }
00824               
00825           ++i;
00826         }
00827     }
00828       
00829  next_iteration:
00830 #if MAINLOOP_SPEW
00831   _dbus_verbose ("  moving to next iteration\n");
00832 #endif
00833   
00834   if (fds && fds != stack_fds)
00835     dbus_free (fds);
00836   if (watches_for_fds)
00837     {
00838       i = 0;
00839       while (i < n_fds)
00840         {
00841           callback_unref (&watches_for_fds[i]->callback);
00842           ++i;
00843         }
00844       
00845       if (watches_for_fds != stack_watches_for_fds)
00846         dbus_free (watches_for_fds);
00847     }
00848   
00849   if (_dbus_loop_dispatch (loop))
00850     retval = TRUE;
00851   
00852 #if MAINLOOP_SPEW
00853   _dbus_verbose ("Returning %d\n", retval);
00854 #endif
00855   
00856   return retval;
00857 }
00858 
00859 void
00860 _dbus_loop_run (DBusLoop *loop)
00861 {
00862   int our_exit_depth;
00863 
00864   _dbus_assert (loop->depth >= 0);
00865   
00866   _dbus_loop_ref (loop);
00867   
00868   our_exit_depth = loop->depth;
00869   loop->depth += 1;
00870 
00871   _dbus_verbose ("Running main loop, depth %d -> %d\n",
00872                  loop->depth - 1, loop->depth);
00873   
00874   while (loop->depth != our_exit_depth)
00875     _dbus_loop_iterate (loop, TRUE);
00876 
00877   _dbus_loop_unref (loop);
00878 }
00879 
00880 void
00881 _dbus_loop_quit (DBusLoop *loop)
00882 {
00883   _dbus_assert (loop->depth > 0);  
00884   
00885   loop->depth -= 1;
00886 
00887   _dbus_verbose ("Quit main loop, depth %d -> %d\n",
00888                  loop->depth + 1, loop->depth);
00889 }
00890 
00891 int
00892 _dbus_get_oom_wait (void)
00893 {
00894 #ifdef DBUS_BUILD_TESTS
00895   /* make tests go fast */
00896   return 0;
00897 #else
00898   return 500;
00899 #endif
00900 }
00901 
00902 void
00903 _dbus_wait_for_memory (void)
00904 {
00905   _dbus_verbose ("Waiting for more memory\n");
00906   _dbus_sleep_milliseconds (_dbus_get_oom_wait ());
00907 }
00908 
00909 #endif /* !DOXYGEN_SHOULD_SKIP_THIS */

Generated on Fri Jul 22 2011 16:59:34 for D-Bus by  doxygen 1.7.1