1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
4 * gthread.c: thread related functions
5 * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser 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.
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 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser 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.
24 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
25 * file for a list of people on the GLib Team. See the ChangeLog
26 * files for a list of changes. These files are distributed with
27 * GLib at ftp://ftp.gtk.org/pub/gtk/.
40 #ifdef G_THREAD_ENABLED
42 static gboolean thread_system_already_initialized = FALSE;
43 static gint g_thread_priority_map [G_THREAD_PRIORITY_URGENT + 1];
45 #include G_THREAD_SOURCE
47 #ifndef PRIORITY_LOW_VALUE
48 # define PRIORITY_LOW_VALUE 0
51 #ifndef PRIORITY_URGENT_VALUE
52 # define PRIORITY_URGENT_VALUE 0
55 #ifndef PRIORITY_NORMAL_VALUE
56 # define PRIORITY_NORMAL_VALUE \
57 (PRIORITY_LOW_VALUE + (PRIORITY_URGENT_VALUE - PRIORITY_LOW_VALUE) * 4 / 10)
58 #endif /* PRIORITY_NORMAL_VALUE */
60 #ifndef PRIORITY_HIGH_VALUE
61 # define PRIORITY_HIGH_VALUE \
62 (PRIORITY_LOW_VALUE + (PRIORITY_URGENT_VALUE - PRIORITY_LOW_VALUE) * 8 / 10)
63 #endif /* PRIORITY_HIGH_VALUE */
65 void g_mutex_init (void);
66 void g_mem_init (void);
67 void g_messages_init (void);
69 #define G_MUTEX_DEBUG_INFO(mutex) (*((gpointer*)(((char*)mutex)+G_MUTEX_SIZE)))
71 typedef struct _ErrorCheckInfo ErrorCheckInfo;
72 struct _ErrorCheckInfo
79 g_mutex_new_errorcheck_impl (void)
81 GMutex *retval = g_thread_functions_for_glib_use_default.mutex_new ();
82 retval = g_realloc (retval, G_MUTEX_SIZE + sizeof (gpointer));
83 G_MUTEX_DEBUG_INFO (retval) = NULL;
88 g_mutex_lock_errorcheck_impl (GMutex *mutex,
93 GThread *self = g_thread_self ();
95 if (magic != G_MUTEX_DEBUG_MAGIC)
98 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
100 /* if the debug info is NULL, we have not yet locked that mutex,
102 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
103 /* Now we have to check again, because another thread might have
104 * tried to lock the mutex at the same time we did. This
105 * technique is not 100% save on systems without decent cache
106 * coherence, but we have no choice */
107 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
109 info = G_MUTEX_DEBUG_INFO (mutex) = g_new0 (ErrorCheckInfo, 1);
111 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
114 info = G_MUTEX_DEBUG_INFO (mutex);
115 if (info->owner == self)
116 g_error ("Trying to recursivly lock a mutex at '%s', "
117 "previously locked at '%s'",
118 location, info->location);
120 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
123 info->location = location;
127 g_mutex_trylock_errorcheck_impl (GMutex *mutex,
131 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
132 GThread *self = g_thread_self ();
134 if (magic != G_MUTEX_DEBUG_MAGIC)
135 location = "unknown";
139 /* This mutex has not yet been used, so simply lock and return TRUE */
140 g_mutex_lock_errorcheck_impl (mutex, magic, location);
144 if (info->owner == self)
145 g_error ("Trying to recursivly lock a mutex at '%s', "
146 "previously locked at '%s'",
147 location, info->location);
149 if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))
153 info->location = location;
159 g_mutex_unlock_errorcheck_impl (GMutex *mutex,
163 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
164 GThread *self = g_thread_self ();
166 if (magic != G_MUTEX_DEBUG_MAGIC)
167 location = "unknown";
169 if (!info || info->owner == NULL)
170 g_error ("Trying to unlock an unlocked mutex at '%s'", location);
172 if (info->owner != self)
173 g_warning ("Trying to unlock a mutex at '%s', "
174 "previously locked by a different thread at '%s'",
175 location, info->location);
178 info->location = NULL;
180 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
184 g_mutex_free_errorcheck_impl (GMutex *mutex,
188 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
190 if (magic != G_MUTEX_DEBUG_MAGIC)
191 location = "unknown";
193 if (info && info->owner != NULL)
194 g_error ("Trying to free a locked mutex at '%s', "
195 "which was previously locked at '%s'",
196 location, info->location);
198 g_free (G_MUTEX_DEBUG_INFO (mutex));
199 g_thread_functions_for_glib_use_default.mutex_free (mutex);
203 g_cond_wait_errorcheck_impl (GCond *cond,
209 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
210 GThread *self = g_thread_self ();
212 if (magic != G_MUTEX_DEBUG_MAGIC)
213 location = "unknown";
215 if (!info || info->owner == NULL)
216 g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'",
219 if (info->owner != self)
220 g_error ("Trying to use a mutex locked by another thread in "
221 "g_cond_wait() at '%s'", location);
224 location = info->location;
226 g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);
229 info->location = location;
234 g_cond_timed_wait_errorcheck_impl (GCond *cond,
240 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
241 GThread *self = g_thread_self ();
244 if (magic != G_MUTEX_DEBUG_MAGIC)
245 location = "unknown";
247 if (!info || info->owner == NULL)
248 g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",
251 if (info->owner != self)
252 g_error ("Trying to use a mutex locked by another thread in "
253 "g_cond_timed_wait() at '%s'", location);
256 location = info->location;
258 retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond,
263 info->location = location;
269 /* unshadow function declaration. See gthread.h */
273 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
275 GThreadFunctions errorcheck_functions;
277 g_error ("Errorcheck mutexes can only be used for native "
278 "thread implementations. Sorry." );
280 #ifdef HAVE_G_THREAD_IMPL_INIT
281 /* This isn't called in g_thread_init, as it doesn't think to get
282 * the default implementation, so we have to call it on our own.
284 * We must call this before copying
285 * g_thread_functions_for_glib_use_default as the
286 * implementation-specific init function might modify the contents
287 * of g_thread_functions_for_glib_use_default based on operating
288 * system version, C library version, or whatever. */
289 g_thread_impl_init();
290 #endif /* HAVE_G_THREAD_IMPL_INIT */
292 errorcheck_functions = g_thread_functions_for_glib_use_default;
293 errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;
294 errorcheck_functions.mutex_lock =
295 (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;
296 errorcheck_functions.mutex_trylock =
297 (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;
298 errorcheck_functions.mutex_unlock =
299 (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;
300 errorcheck_functions.mutex_free =
301 (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;
302 errorcheck_functions.cond_wait =
303 (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;
304 errorcheck_functions.cond_timed_wait =
305 (gboolean (*)(GCond *, GMutex *, GTimeVal *))
306 g_cond_timed_wait_errorcheck_impl;
308 g_thread_init (&errorcheck_functions);
312 g_thread_init (GThreadFunctions* init)
316 if (thread_system_already_initialized)
317 g_error ("GThread system may only be initialized once.");
319 thread_system_already_initialized = TRUE;
323 #ifdef HAVE_G_THREAD_IMPL_INIT
324 /* now do any initialization stuff required by the
325 * implementation, but only if called with a NULL argument, of
326 * course. Otherwise it's up to the user to do so. */
327 g_thread_impl_init();
328 #endif /* HAVE_G_THREAD_IMPL_INIT */
329 init = &g_thread_functions_for_glib_use_default;
332 g_thread_use_default_impl = FALSE;
334 g_thread_functions_for_glib_use = *init;
336 /* It is important, that g_threads_got_initialized is not set before the
337 * thread initialization functions of the different modules are called
339 supported = (init->mutex_new &&
341 init->mutex_trylock &&
342 init->mutex_unlock &&
346 init->cond_broadcast &&
348 init->cond_timed_wait &&
353 init->thread_create &&
354 init->thread_yield &&
357 init->thread_set_priority &&
360 /* if somebody is calling g_thread_init (), it means that he wants to
361 * have thread support, so check this
365 if (g_thread_use_default_impl)
366 g_error ("Threads are not supported on this platform.");
368 g_error ("The supplied thread function vector is invalid.");
371 g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;
372 g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;
373 g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;
374 g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;
376 /* now call the thread initialization functions of the different
377 * glib modules. order does matter, g_mutex_init MUST come first.
383 /* now we can set g_threads_got_initialized and thus enable
384 * all the thread functions
386 g_threads_got_initialized = TRUE;
388 /* we want the main thread to run with normal priority */
389 g_thread_set_priority (g_thread_self(), G_THREAD_PRIORITY_NORMAL);
392 #else /* !G_THREADS_ENABLED */
395 g_thread_init (GThreadFunctions* init)
397 g_error ("GLib thread support is disabled.");
400 #endif /* !G_THREADS_ENABLED */