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/.
37 #include "gthreadprivate.h"
39 #ifdef G_THREADS_ENABLED
41 static GSystemThread zero_thread; /* This is initialized to all zero */
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,
98 g_thread_functions_for_glib_use.thread_self (&self);
100 if (magic != G_MUTEX_DEBUG_MAGIC)
101 location = "unknown";
103 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
105 /* if the debug info is NULL, we have not yet locked that mutex,
107 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
108 /* Now we have to check again, because another thread might have
109 * tried to lock the mutex at the same time we did. This
110 * technique is not 100% save on systems without decent cache
111 * coherence, but we have no choice */
112 if (G_MUTEX_DEBUG_INFO (mutex) == NULL)
114 info = G_MUTEX_DEBUG_INFO (mutex) = g_new0 (ErrorCheckInfo, 1);
116 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
119 info = G_MUTEX_DEBUG_INFO (mutex);
120 if (g_system_thread_equal (info->owner, self))
121 g_error ("Trying to recursivly lock a mutex at '%s', "
122 "previously locked at '%s'",
123 location, info->location);
125 g_thread_functions_for_glib_use_default.mutex_lock (mutex);
127 g_system_thread_assign (info->owner, self);
128 info->location = location;
132 g_mutex_trylock_errorcheck_impl (GMutex *mutex,
136 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
139 g_thread_functions_for_glib_use.thread_self (&self);
141 if (magic != G_MUTEX_DEBUG_MAGIC)
142 location = "unknown";
146 /* This mutex has not yet been used, so simply lock and return TRUE */
147 g_mutex_lock_errorcheck_impl (mutex, magic, location);
151 if (g_system_thread_equal (info->owner, self))
152 g_error ("Trying to recursivly lock a mutex at '%s', "
153 "previously locked at '%s'",
154 location, info->location);
156 if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))
159 g_system_thread_assign (info->owner, self);
160 info->location = location;
166 g_mutex_unlock_errorcheck_impl (GMutex *mutex,
170 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
173 g_thread_functions_for_glib_use.thread_self (&self);
175 if (magic != G_MUTEX_DEBUG_MAGIC)
176 location = "unknown";
178 if (!info || g_system_thread_equal (info->owner, zero_thread))
179 g_error ("Trying to unlock an unlocked mutex at '%s'", location);
181 if (!g_system_thread_equal (info->owner, self))
182 g_warning ("Trying to unlock a mutex at '%s', "
183 "previously locked by a different thread at '%s'",
184 location, info->location);
186 g_system_thread_assign (info->owner, zero_thread);
187 info->location = NULL;
189 g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
193 g_mutex_free_errorcheck_impl (GMutex *mutex,
197 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
199 if (magic != G_MUTEX_DEBUG_MAGIC)
200 location = "unknown";
202 if (info && !g_system_thread_equal (info->owner, zero_thread))
203 g_error ("Trying to free a locked mutex at '%s', "
204 "which was previously locked at '%s'",
205 location, info->location);
207 g_free (G_MUTEX_DEBUG_INFO (mutex));
208 g_thread_functions_for_glib_use_default.mutex_free (mutex);
212 g_cond_wait_errorcheck_impl (GCond *cond,
218 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
221 g_thread_functions_for_glib_use.thread_self (&self);
223 if (magic != G_MUTEX_DEBUG_MAGIC)
224 location = "unknown";
226 if (!info || g_system_thread_equal (info->owner, zero_thread))
227 g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'",
230 if (!g_system_thread_equal (info->owner, self))
231 g_error ("Trying to use a mutex locked by another thread in "
232 "g_cond_wait() at '%s'", location);
234 g_system_thread_assign (info->owner, zero_thread);
235 location = info->location;
237 g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);
239 g_system_thread_assign (info->owner, self);
240 info->location = location;
245 g_cond_timed_wait_errorcheck_impl (GCond *cond,
251 ErrorCheckInfo *info = G_MUTEX_DEBUG_INFO (mutex);
255 g_thread_functions_for_glib_use.thread_self (&self);
257 if (magic != G_MUTEX_DEBUG_MAGIC)
258 location = "unknown";
260 if (!info || g_system_thread_equal (info->owner, zero_thread))
261 g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",
264 if (!g_system_thread_equal (info->owner, self))
265 g_error ("Trying to use a mutex locked by another thread in "
266 "g_cond_timed_wait() at '%s'", location);
268 g_system_thread_assign (info->owner, zero_thread);
269 location = info->location;
271 retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond,
275 g_system_thread_assign (info->owner, self);
276 info->location = location;
282 /* unshadow function declaration. See gthread.h */
286 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
288 GThreadFunctions errorcheck_functions;
290 g_error ("Errorcheck mutexes can only be used for native "
291 "thread implementations. Sorry." );
293 #ifdef HAVE_G_THREAD_IMPL_INIT
294 /* This isn't called in g_thread_init, as it doesn't think to get
295 * the default implementation, so we have to call it on our own.
297 * We must call this before copying
298 * g_thread_functions_for_glib_use_default as the
299 * implementation-specific init function might modify the contents
300 * of g_thread_functions_for_glib_use_default based on operating
301 * system version, C library version, or whatever. */
302 g_thread_impl_init();
303 #endif /* HAVE_G_THREAD_IMPL_INIT */
305 errorcheck_functions = g_thread_functions_for_glib_use_default;
306 errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;
307 errorcheck_functions.mutex_lock =
308 (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;
309 errorcheck_functions.mutex_trylock =
310 (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;
311 errorcheck_functions.mutex_unlock =
312 (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;
313 errorcheck_functions.mutex_free =
314 (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;
315 errorcheck_functions.cond_wait =
316 (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;
317 errorcheck_functions.cond_timed_wait =
318 (gboolean (*)(GCond *, GMutex *, GTimeVal *))
319 g_cond_timed_wait_errorcheck_impl;
321 g_thread_init (&errorcheck_functions);
325 g_thread_init (GThreadFunctions* init)
329 if (thread_system_already_initialized)
330 g_error ("GThread system may only be initialized once.");
332 thread_system_already_initialized = TRUE;
336 #ifdef HAVE_G_THREAD_IMPL_INIT
337 /* now do any initialization stuff required by the
338 * implementation, but only if called with a NULL argument, of
339 * course. Otherwise it's up to the user to do so. */
340 g_thread_impl_init();
341 #endif /* HAVE_G_THREAD_IMPL_INIT */
342 init = &g_thread_functions_for_glib_use_default;
345 g_thread_use_default_impl = FALSE;
347 g_thread_functions_for_glib_use = *init;
349 supported = (init->mutex_new &&
351 init->mutex_trylock &&
352 init->mutex_unlock &&
356 init->cond_broadcast &&
358 init->cond_timed_wait &&
363 init->thread_create &&
364 init->thread_yield &&
367 init->thread_set_priority &&
370 /* if somebody is calling g_thread_init (), it means that he wants to
371 * have thread support, so check this
375 if (g_thread_use_default_impl)
376 g_error ("Threads are not supported on this platform.");
378 g_error ("The supplied thread function vector is invalid.");
381 g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;
382 g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;
383 g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;
384 g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;
386 g_thread_init_glib ();
389 #else /* !G_THREADS_ENABLED */
392 g_thread_init (GThreadFunctions* init)
394 g_error ("GLib thread support is disabled.");
397 #endif /* !G_THREADS_ENABLED */