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);
69 void g_rand_init (void);
70 void g_main_thread_init (void);
72 #define G_MUTEX_DEBUG_INFO(mutex) (*((gpointer*)(((char*)mutex)+G_MUTEX_SIZE)))
74 typedef struct _ErrorCheckInfo ErrorCheckInfo;
75 struct _ErrorCheckInfo
82 g_mutex_new_errorcheck_impl (void)
84 GMutex *retval = g_thread_functions_for_glib_use_default.mutex_new ();
85 retval = g_realloc (retval, G_MUTEX_SIZE + sizeof (gpointer));
86 G_MUTEX_DEBUG_INFO (retval) = NULL;
91 g_mutex_lock_errorcheck_impl (GMutex *mutex,
96 GThread *self = g_thread_self ();
98 if (magic != G_MUTEX_DEBUG_MAGIC)
101 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
103 /* if the debug info is NULL, we have not yet locked that mutex,
105 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
106 /* Now we have to check again, because another thread might have
107 * tried to lock the mutex at the same time we did. This
108 * technique is not 100% save on systems without decent cache
109 * coherence, but we have no choice */
110 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
112 info = G_MUTEX_DEBUG_INFO (mutex) = g_new0 (ErrorCheckInfo, 1);
114 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
117 info = G_MUTEX_DEBUG_INFO (mutex);
118 if (info->owner == self)
119 g_error ("Trying to recursivly lock a mutex at '%s', "
120 "previously locked at '%s'",
121 location, info->location);
123 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
126 info->location = location;
130 g_mutex_trylock_errorcheck_impl (GMutex *mutex,
134 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
135 GThread *self = g_thread_self ();
137 if (magic != G_MUTEX_DEBUG_MAGIC)
138 location = "unknown";
142 /* This mutex has not yet been used, so simply lock and return TRUE */
143 g_mutex_lock_errorcheck_impl (mutex, magic, location);
147 if (info->owner == self)
148 g_error ("Trying to recursivly lock a mutex at '%s', "
149 "previously locked at '%s'",
150 location, info->location);
152 if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))
156 info->location = location;
162 g_mutex_unlock_errorcheck_impl (GMutex *mutex,
166 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
167 GThread *self = g_thread_self ();
169 if (magic != G_MUTEX_DEBUG_MAGIC)
170 location = "unknown";
172 if (!info || info->owner == NULL)
173 g_error ("Trying to unlock an unlocked mutex at '%s'", location);
175 if (info->owner != self)
176 g_warning ("Trying to unlock a mutex at '%s', "
177 "previously locked by a different thread at '%s'",
178 location, info->location);
181 info->location = NULL;
183 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
187 g_mutex_free_errorcheck_impl (GMutex *mutex,
191 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
193 if (magic != G_MUTEX_DEBUG_MAGIC)
194 location = "unknown";
196 if (info && info->owner != NULL)
197 g_error ("Trying to free a locked mutex at '%s', "
198 "which was previously locked at '%s'",
199 location, info->location);
201 g_free (G_MUTEX_DEBUG_INFO (mutex));
202 g_thread_functions_for_glib_use_default.mutex_free (mutex);
206 g_cond_wait_errorcheck_impl (GCond *cond,
212 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
213 GThread *self = g_thread_self ();
215 if (magic != G_MUTEX_DEBUG_MAGIC)
216 location = "unknown";
218 if (!info || info->owner == NULL)
219 g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'",
222 if (info->owner != self)
223 g_error ("Trying to use a mutex locked by another thread in "
224 "g_cond_wait() at '%s'", location);
227 location = info->location;
229 g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);
232 info->location = location;
237 g_cond_timed_wait_errorcheck_impl (GCond *cond,
243 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
244 GThread *self = g_thread_self ();
247 if (magic != G_MUTEX_DEBUG_MAGIC)
248 location = "unknown";
250 if (!info || info->owner == NULL)
251 g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",
254 if (info->owner != self)
255 g_error ("Trying to use a mutex locked by another thread in "
256 "g_cond_timed_wait() at '%s'", location);
259 location = info->location;
261 retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond,
266 info->location = location;
272 /* unshadow function declaration. See gthread.h */
276 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
278 GThreadFunctions errorcheck_functions;
280 g_error ("Errorcheck mutexes can only be used for native "
281 "thread implementations. Sorry." );
283 #ifdef HAVE_G_THREAD_IMPL_INIT
284 /* This isn't called in g_thread_init, as it doesn't think to get
285 * the default implementation, so we have to call it on our own.
287 * We must call this before copying
288 * g_thread_functions_for_glib_use_default as the
289 * implementation-specific init function might modify the contents
290 * of g_thread_functions_for_glib_use_default based on operating
291 * system version, C library version, or whatever. */
292 g_thread_impl_init();
293 #endif /* HAVE_G_THREAD_IMPL_INIT */
295 errorcheck_functions = g_thread_functions_for_glib_use_default;
296 errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;
297 errorcheck_functions.mutex_lock =
298 (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;
299 errorcheck_functions.mutex_trylock =
300 (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;
301 errorcheck_functions.mutex_unlock =
302 (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;
303 errorcheck_functions.mutex_free =
304 (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;
305 errorcheck_functions.cond_wait =
306 (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;
307 errorcheck_functions.cond_timed_wait =
308 (gboolean (*)(GCond *, GMutex *, GTimeVal *))
309 g_cond_timed_wait_errorcheck_impl;
311 g_thread_init (&errorcheck_functions);
315 g_thread_init (GThreadFunctions* init)
319 if (thread_system_already_initialized)
320 g_error ("GThread system may only be initialized once.");
322 thread_system_already_initialized = TRUE;
326 #ifdef HAVE_G_THREAD_IMPL_INIT
327 /* now do any initialization stuff required by the
328 * implementation, but only if called with a NULL argument, of
329 * course. Otherwise it's up to the user to do so. */
330 g_thread_impl_init();
331 #endif /* HAVE_G_THREAD_IMPL_INIT */
332 init = &g_thread_functions_for_glib_use_default;
335 g_thread_use_default_impl = FALSE;
337 g_thread_functions_for_glib_use = *init;
339 /* It is important, that g_threads_got_initialized is not set before the
340 * thread initialization functions of the different modules are called
342 supported = (init->mutex_new &&
344 init->mutex_trylock &&
345 init->mutex_unlock &&
349 init->cond_broadcast &&
351 init->cond_timed_wait &&
356 init->thread_create &&
357 init->thread_yield &&
360 init->thread_set_priority &&
363 /* if somebody is calling g_thread_init (), it means that he wants to
364 * have thread support, so check this
368 if (g_thread_use_default_impl)
369 g_error ("Threads are not supported on this platform.");
371 g_error ("The supplied thread function vector is invalid.");
374 g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;
375 g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;
376 g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;
377 g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;
379 /* now call the thread initialization functions of the different
380 * glib modules. order does matter, g_mutex_init MUST come first.
387 g_main_thread_init ();
389 /* now we can set g_threads_got_initialized and thus enable
390 * all the thread functions
392 g_threads_got_initialized = TRUE;
395 #else /* !G_THREADS_ENABLED */
398 g_thread_init (GThreadFunctions* init)
400 g_error ("GLib thread support is disabled.");
403 #endif /* !G_THREADS_ENABLED */