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_THREADS_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 * 6 + PRIORITY_URGENT_VALUE * 4) / 10)
58 #endif /* PRIORITY_NORMAL_VALUE */
60 #ifndef PRIORITY_HIGH_VALUE
61 # define PRIORITY_HIGH_VALUE \
62 ((PRIORITY_NORMAL_VALUE + PRIORITY_URGENT_VALUE * 2) / 3)
63 #endif /* PRIORITY_HIGH_VALUE */
65 void g_mutex_init (void);
66 void g_mem_init (void);
67 void g_messages_init (void);
68 void g_convert_init (void);
70 #define G_MUTEX_DEBUG_INFO(mutex) (*((gpointer*)(((char*)mutex)+G_MUTEX_SIZE)))
72 typedef struct _ErrorCheckInfo ErrorCheckInfo;
73 struct _ErrorCheckInfo
80 g_mutex_new_errorcheck_impl (void)
82 GMutex *retval = g_thread_functions_for_glib_use_default.mutex_new ();
83 retval = g_realloc (retval, G_MUTEX_SIZE + sizeof (gpointer));
84 G_MUTEX_DEBUG_INFO (retval) = NULL;
89 g_mutex_lock_errorcheck_impl (GMutex *mutex,
94 GThread *self = g_thread_self ();
96 if (magic != G_MUTEX_DEBUG_MAGIC)
99 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
101 /* if the debug info is NULL, we have not yet locked that mutex,
103 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
104 /* Now we have to check again, because another thread might have
105 * tried to lock the mutex at the same time we did. This
106 * technique is not 100% save on systems without decent cache
107 * coherence, but we have no choice */
108 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
110 info = G_MUTEX_DEBUG_INFO (mutex) = g_new0 (ErrorCheckInfo, 1);
112 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
115 info = G_MUTEX_DEBUG_INFO (mutex);
116 if (info->owner == self)
117 g_error ("Trying to recursivly lock a mutex at '%s', "
118 "previously locked at '%s'",
119 location, info->location);
121 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
124 info->location = location;
128 g_mutex_trylock_errorcheck_impl (GMutex *mutex,
132 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
133 GThread *self = g_thread_self ();
135 if (magic != G_MUTEX_DEBUG_MAGIC)
136 location = "unknown";
140 /* This mutex has not yet been used, so simply lock and return TRUE */
141 g_mutex_lock_errorcheck_impl (mutex, magic, location);
145 if (info->owner == self)
146 g_error ("Trying to recursivly lock a mutex at '%s', "
147 "previously locked at '%s'",
148 location, info->location);
150 if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))
154 info->location = location;
160 g_mutex_unlock_errorcheck_impl (GMutex *mutex,
164 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
165 GThread *self = g_thread_self ();
167 if (magic != G_MUTEX_DEBUG_MAGIC)
168 location = "unknown";
170 if (!info || info->owner == NULL)
171 g_error ("Trying to unlock an unlocked mutex at '%s'", location);
173 if (info->owner != self)
174 g_warning ("Trying to unlock a mutex at '%s', "
175 "previously locked by a different thread at '%s'",
176 location, info->location);
179 info->location = NULL;
181 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
185 g_mutex_free_errorcheck_impl (GMutex *mutex,
189 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
191 if (magic != G_MUTEX_DEBUG_MAGIC)
192 location = "unknown";
194 if (info && info->owner != NULL)
195 g_error ("Trying to free a locked mutex at '%s', "
196 "which was previously locked at '%s'",
197 location, info->location);
199 g_free (G_MUTEX_DEBUG_INFO (mutex));
200 g_thread_functions_for_glib_use_default.mutex_free (mutex);
204 g_cond_wait_errorcheck_impl (GCond *cond,
210 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
211 GThread *self = g_thread_self ();
213 if (magic != G_MUTEX_DEBUG_MAGIC)
214 location = "unknown";
216 if (!info || info->owner == NULL)
217 g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'",
220 if (info->owner != self)
221 g_error ("Trying to use a mutex locked by another thread in "
222 "g_cond_wait() at '%s'", location);
225 location = info->location;
227 g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);
230 info->location = location;
235 g_cond_timed_wait_errorcheck_impl (GCond *cond,
241 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
242 GThread *self = g_thread_self ();
245 if (magic != G_MUTEX_DEBUG_MAGIC)
246 location = "unknown";
248 if (!info || info->owner == NULL)
249 g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",
252 if (info->owner != self)
253 g_error ("Trying to use a mutex locked by another thread in "
254 "g_cond_timed_wait() at '%s'", location);
257 location = info->location;
259 retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond,
264 info->location = location;
270 /* unshadow function declaration. See gthread.h */
274 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
276 GThreadFunctions errorcheck_functions;
278 g_error ("Errorcheck mutexes can only be used for native "
279 "thread implementations. Sorry." );
281 #ifdef HAVE_G_THREAD_IMPL_INIT
282 /* This isn't called in g_thread_init, as it doesn't think to get
283 * the default implementation, so we have to call it on our own.
285 * We must call this before copying
286 * g_thread_functions_for_glib_use_default as the
287 * implementation-specific init function might modify the contents
288 * of g_thread_functions_for_glib_use_default based on operating
289 * system version, C library version, or whatever. */
290 g_thread_impl_init();
291 #endif /* HAVE_G_THREAD_IMPL_INIT */
293 errorcheck_functions = g_thread_functions_for_glib_use_default;
294 errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;
295 errorcheck_functions.mutex_lock =
296 (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;
297 errorcheck_functions.mutex_trylock =
298 (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;
299 errorcheck_functions.mutex_unlock =
300 (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;
301 errorcheck_functions.mutex_free =
302 (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;
303 errorcheck_functions.cond_wait =
304 (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;
305 errorcheck_functions.cond_timed_wait =
306 (gboolean (*)(GCond *, GMutex *, GTimeVal *))
307 g_cond_timed_wait_errorcheck_impl;
309 g_thread_init (&errorcheck_functions);
313 g_thread_init (GThreadFunctions* init)
317 if (thread_system_already_initialized)
318 g_error ("GThread system may only be initialized once.");
320 thread_system_already_initialized = TRUE;
324 #ifdef HAVE_G_THREAD_IMPL_INIT
325 /* now do any initialization stuff required by the
326 * implementation, but only if called with a NULL argument, of
327 * course. Otherwise it's up to the user to do so. */
328 g_thread_impl_init();
329 #endif /* HAVE_G_THREAD_IMPL_INIT */
330 init = &g_thread_functions_for_glib_use_default;
333 g_thread_use_default_impl = FALSE;
335 g_thread_functions_for_glib_use = *init;
337 /* It is important, that g_threads_got_initialized is not set before the
338 * thread initialization functions of the different modules are called
340 supported = (init->mutex_new &&
342 init->mutex_trylock &&
343 init->mutex_unlock &&
347 init->cond_broadcast &&
349 init->cond_timed_wait &&
354 init->thread_create &&
355 init->thread_yield &&
358 init->thread_set_priority &&
361 /* if somebody is calling g_thread_init (), it means that he wants to
362 * have thread support, so check this
366 if (g_thread_use_default_impl)
367 g_error ("Threads are not supported on this platform.");
369 g_error ("The supplied thread function vector is invalid.");
372 g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;
373 g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;
374 g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;
375 g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;
377 /* now call the thread initialization functions of the different
378 * glib modules. order does matter, g_mutex_init MUST come first.
385 /* now we can set g_threads_got_initialized and thus enable
386 * all the thread functions
388 g_threads_got_initialized = TRUE;
391 #else /* !G_THREADS_ENABLED */
394 g_thread_init (GThreadFunctions* init)
396 g_error ("GLib thread support is disabled.");
399 #endif /* !G_THREADS_ENABLED */