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dbus-threads.c

00001 /* -*- mode: C; c-file-style: "gnu" -*- */
00002 /* dbus-threads.h  D-BUS threads handling
00003  *
00004  * Copyright (C) 2002, 2003 Red Hat Inc.
00005  *
00006  * Licensed under the Academic Free License version 2.0
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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
00021  *
00022  */
00023 #include "dbus-threads.h"
00024 #include "dbus-internals.h"
00025 
00026 static DBusThreadFunctions thread_functions =
00027 {
00028   0,
00029   NULL, NULL, NULL, NULL,
00030   NULL, NULL, NULL, NULL, NULL,
00031 
00032   NULL, NULL, NULL, NULL,
00033   NULL, NULL, NULL, NULL
00034 };
00035 static int thread_init_generation = 0;
00036 
00038 #define _DBUS_DUMMY_MUTEX ((DBusMutex*)0xABCDEF)
00039 
00041 #define _DBUS_DUMMY_CONDVAR ((DBusCondVar*)0xABCDEF2)
00042 
00061 DBusMutex*
00062 dbus_mutex_new (void)
00063 {
00064   if (thread_functions.mutex_new)
00065     return (* thread_functions.mutex_new) ();
00066   else
00067     return _DBUS_DUMMY_MUTEX;
00068 }
00069 
00074 void
00075 dbus_mutex_free (DBusMutex *mutex)
00076 {
00077   if (mutex && thread_functions.mutex_free)
00078     (* thread_functions.mutex_free) (mutex);
00079 }
00080 
00087 dbus_bool_t
00088 dbus_mutex_lock (DBusMutex *mutex)
00089 {
00090   if (mutex && thread_functions.mutex_lock)
00091     return (* thread_functions.mutex_lock) (mutex);
00092   else
00093     return TRUE;
00094 }
00095 
00101 dbus_bool_t
00102 dbus_mutex_unlock (DBusMutex *mutex)
00103 {
00104   if (mutex && thread_functions.mutex_unlock)
00105     return (* thread_functions.mutex_unlock) (mutex);
00106   else
00107     return TRUE;
00108 }
00109 
00118 DBusCondVar *
00119 dbus_condvar_new (void)
00120 {
00121   if (thread_functions.condvar_new)
00122     return (* thread_functions.condvar_new) ();
00123   else
00124     return _DBUS_DUMMY_CONDVAR;
00125 }
00126 
00131 void
00132 dbus_condvar_free (DBusCondVar *cond)
00133 {
00134   if (cond && thread_functions.condvar_free)
00135     (* thread_functions.condvar_free) (cond);
00136 }
00137 
00144 void
00145 dbus_condvar_wait (DBusCondVar *cond,
00146                    DBusMutex   *mutex)
00147 {
00148   if (cond && mutex && thread_functions.condvar_wait)
00149     (* thread_functions.condvar_wait) (cond, mutex);
00150 }
00151 
00164 dbus_bool_t
00165 dbus_condvar_wait_timeout (DBusCondVar               *cond,
00166                            DBusMutex                 *mutex,
00167                            int                        timeout_milliseconds)
00168 {
00169   if (cond && mutex && thread_functions.condvar_wait)
00170     return (* thread_functions.condvar_wait_timeout) (cond, mutex, timeout_milliseconds);
00171   else
00172     return TRUE;
00173 }
00174 
00180 void
00181 dbus_condvar_wake_one (DBusCondVar *cond)
00182 {
00183   if (cond && thread_functions.condvar_wake_one)
00184     (* thread_functions.condvar_wake_one) (cond);
00185 }
00186 
00192 void
00193 dbus_condvar_wake_all (DBusCondVar *cond)
00194 {
00195   if (cond && thread_functions.condvar_wake_all)
00196     (* thread_functions.condvar_wake_all) (cond);
00197 }
00198 
00199 static void
00200 shutdown_global_locks (void *data)
00201 {
00202   DBusMutex ***locks = data;
00203   int i;
00204 
00205   i = 0;
00206   while (i < _DBUS_N_GLOBAL_LOCKS)
00207     {
00208       dbus_mutex_free (*(locks[i]));
00209       *(locks[i]) = NULL;
00210       ++i;
00211     }
00212   
00213   dbus_free (locks);
00214 }
00215 
00216 static dbus_bool_t
00217 init_global_locks (void)
00218 {
00219   int i;
00220   DBusMutex ***dynamic_global_locks;
00221   
00222   DBusMutex **global_locks[] = {
00223 #define LOCK_ADDR(name) (& _dbus_lock_##name)
00224     LOCK_ADDR (list),
00225     LOCK_ADDR (connection_slots),
00226     LOCK_ADDR (pending_call_slots),
00227     LOCK_ADDR (server_slots),
00228     LOCK_ADDR (message_slots),
00229     LOCK_ADDR (atomic),
00230     LOCK_ADDR (bus),
00231     LOCK_ADDR (shutdown_funcs),
00232     LOCK_ADDR (system_users)
00233 #undef LOCK_ADDR
00234   };
00235 
00236   _dbus_assert (_DBUS_N_ELEMENTS (global_locks) ==
00237                 _DBUS_N_GLOBAL_LOCKS);
00238 
00239   i = 0;
00240   
00241   dynamic_global_locks = dbus_new (DBusMutex**, _DBUS_N_GLOBAL_LOCKS);
00242   if (dynamic_global_locks == NULL)
00243     goto failed;
00244   
00245   while (i < _DBUS_N_ELEMENTS (global_locks))
00246     {
00247       *global_locks[i] = dbus_mutex_new ();
00248       
00249       if (*global_locks[i] == NULL)
00250         goto failed;
00251 
00252       dynamic_global_locks[i] = global_locks[i];
00253 
00254       ++i;
00255     }
00256   
00257   if (!_dbus_register_shutdown_func (shutdown_global_locks,
00258                                      dynamic_global_locks))
00259     goto failed;
00260   
00261   return TRUE;
00262 
00263  failed:
00264   dbus_free (dynamic_global_locks);
00265                                      
00266   for (i = i - 1; i >= 0; i--)
00267     {
00268       dbus_mutex_free (*global_locks[i]);
00269       *global_locks[i] = NULL;
00270     }
00271   return FALSE;
00272 }
00273 
00274 
00290 dbus_bool_t
00291 dbus_threads_init (const DBusThreadFunctions *functions)
00292 {
00293   _dbus_assert (functions != NULL);
00294 
00295   /* these base functions are required. Future additions to
00296    * DBusThreadFunctions may be optional.
00297    */
00298   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK);
00299   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_MUTEX_FREE_MASK);
00300   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_MUTEX_LOCK_MASK);
00301   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_MUTEX_UNLOCK_MASK);
00302   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK);
00303   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK);
00304   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK);
00305   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK);
00306   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK);
00307   _dbus_assert (functions->mask & DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK);
00308   _dbus_assert (functions->mutex_new != NULL);
00309   _dbus_assert (functions->mutex_free != NULL);
00310   _dbus_assert (functions->mutex_lock != NULL);
00311   _dbus_assert (functions->mutex_unlock != NULL);
00312   _dbus_assert (functions->condvar_new != NULL);
00313   _dbus_assert (functions->condvar_free != NULL);
00314   _dbus_assert (functions->condvar_wait != NULL);
00315   _dbus_assert (functions->condvar_wait_timeout != NULL);
00316   _dbus_assert (functions->condvar_wake_one != NULL);
00317   _dbus_assert (functions->condvar_wake_all != NULL);
00318 
00319   /* Check that all bits in the mask actually are valid mask bits.
00320    * ensures people won't write code that breaks when we add
00321    * new bits.
00322    */
00323   _dbus_assert ((functions->mask & ~DBUS_THREAD_FUNCTIONS_ALL_MASK) == 0);
00324 
00325   if (thread_init_generation != _dbus_current_generation)
00326     thread_functions.mask = 0; /* allow re-init in new generation */
00327   
00328   if (thread_functions.mask != 0)
00329     {
00330       /* Silently allow multiple init if the functions are the same ones.
00331        * Well, we only bother checking two of them, just out of laziness.
00332        */
00333       if (thread_functions.mask == functions->mask &&
00334           thread_functions.mutex_new == functions->mutex_new &&
00335           thread_functions.condvar_new == functions->condvar_new)
00336         {
00337           return TRUE;
00338         }
00339       else
00340         {
00341           _dbus_warn ("dbus_threads_init() called twice with two different sets of functions\n");
00342           return FALSE;
00343         }
00344     }
00345   
00346   thread_functions.mutex_new = functions->mutex_new;
00347   thread_functions.mutex_free = functions->mutex_free;
00348   thread_functions.mutex_lock = functions->mutex_lock;
00349   thread_functions.mutex_unlock = functions->mutex_unlock;
00350   
00351   thread_functions.condvar_new = functions->condvar_new;
00352   thread_functions.condvar_free = functions->condvar_free;
00353   thread_functions.condvar_wait = functions->condvar_wait;
00354   thread_functions.condvar_wait_timeout = functions->condvar_wait_timeout;
00355   thread_functions.condvar_wake_one = functions->condvar_wake_one;
00356   thread_functions.condvar_wake_all = functions->condvar_wake_all;
00357   
00358   thread_functions.mask = functions->mask;
00359 
00360   if (!init_global_locks ())
00361     return FALSE;
00362 
00363   thread_init_generation = _dbus_current_generation;
00364   
00365   return TRUE;
00366 }
00367 
00370 #ifdef DBUS_BUILD_TESTS
00371 
00372 typedef struct DBusFakeMutex DBusFakeMutex;
00374 struct DBusFakeMutex
00375 {
00376   dbus_bool_t locked; 
00377 };      
00378 
00379 static DBusMutex *  dbus_fake_mutex_new            (void);
00380 static void         dbus_fake_mutex_free           (DBusMutex   *mutex);
00381 static dbus_bool_t  dbus_fake_mutex_lock           (DBusMutex   *mutex);
00382 static dbus_bool_t  dbus_fake_mutex_unlock         (DBusMutex   *mutex);
00383 static DBusCondVar* dbus_fake_condvar_new          (void);
00384 static void         dbus_fake_condvar_free         (DBusCondVar *cond);
00385 static void         dbus_fake_condvar_wait         (DBusCondVar *cond,
00386                                                     DBusMutex   *mutex);
00387 static dbus_bool_t  dbus_fake_condvar_wait_timeout (DBusCondVar *cond,
00388                                                     DBusMutex   *mutex,
00389                                                     int          timeout_msec);
00390 static void         dbus_fake_condvar_wake_one     (DBusCondVar *cond);
00391 static void         dbus_fake_condvar_wake_all     (DBusCondVar *cond);
00392 
00393 
00394 static const DBusThreadFunctions fake_functions =
00395 {
00396   DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK |
00397   DBUS_THREAD_FUNCTIONS_MUTEX_FREE_MASK |
00398   DBUS_THREAD_FUNCTIONS_MUTEX_LOCK_MASK |
00399   DBUS_THREAD_FUNCTIONS_MUTEX_UNLOCK_MASK |
00400   DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK |
00401   DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK |
00402   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK |
00403   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK |
00404   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK|
00405   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK,
00406   dbus_fake_mutex_new,
00407   dbus_fake_mutex_free,
00408   dbus_fake_mutex_lock,
00409   dbus_fake_mutex_unlock,
00410   dbus_fake_condvar_new,
00411   dbus_fake_condvar_free,
00412   dbus_fake_condvar_wait,
00413   dbus_fake_condvar_wait_timeout,
00414   dbus_fake_condvar_wake_one,
00415   dbus_fake_condvar_wake_all
00416 };
00417 
00418 static DBusMutex *
00419 dbus_fake_mutex_new (void)
00420 {
00421   DBusFakeMutex *mutex;
00422 
00423   mutex = dbus_new0 (DBusFakeMutex, 1);
00424 
00425   return (DBusMutex *)mutex;
00426 }
00427 
00428 static void
00429 dbus_fake_mutex_free (DBusMutex *mutex)
00430 {
00431   DBusFakeMutex *fake = (DBusFakeMutex*) mutex;
00432 
00433   _dbus_assert (!fake->locked);
00434   
00435   dbus_free (fake);
00436 }
00437 
00438 static dbus_bool_t
00439 dbus_fake_mutex_lock (DBusMutex *mutex)
00440 {
00441   DBusFakeMutex *fake = (DBusFakeMutex*) mutex;
00442 
00443   _dbus_assert (!fake->locked);
00444 
00445   fake->locked = TRUE;
00446   
00447   return TRUE;
00448 }
00449 
00450 static dbus_bool_t
00451 dbus_fake_mutex_unlock (DBusMutex *mutex)
00452 {
00453   DBusFakeMutex *fake = (DBusFakeMutex*) mutex;
00454 
00455   _dbus_assert (fake->locked);
00456 
00457   fake->locked = FALSE;
00458   
00459   return TRUE;
00460 }
00461 
00462 static DBusCondVar*
00463 dbus_fake_condvar_new (void)
00464 {
00465   return (DBusCondVar*) _dbus_strdup ("FakeCondvar");
00466 }
00467 
00468 static void
00469 dbus_fake_condvar_free (DBusCondVar *cond)
00470 {
00471   dbus_free (cond);
00472 }
00473 
00474 static void
00475 dbus_fake_condvar_wait (DBusCondVar *cond,
00476                         DBusMutex   *mutex)
00477 {
00478   
00479 }
00480 
00481 static dbus_bool_t
00482 dbus_fake_condvar_wait_timeout (DBusCondVar *cond,
00483                                 DBusMutex   *mutex,
00484                                 int         timeout_msec)
00485 {
00486   return TRUE;
00487 }
00488 
00489 static void
00490 dbus_fake_condvar_wake_one (DBusCondVar *cond)
00491 {
00492 
00493 }
00494 
00495 static void
00496 dbus_fake_condvar_wake_all (DBusCondVar *cond)
00497 {
00498 
00499 }
00500 
00501 dbus_bool_t
00502 _dbus_threads_init_debug (void)
00503 {
00504   return dbus_threads_init (&fake_functions);
00505 }
00506 
00507 #endif /* DBUS_BUILD_TESTS */

Generated on Wed Jun 9 05:01:27 2004 for D-BUS by doxygen1.2.15