1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with this library; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 02111-1307, USA.
18 */
19
20 /*
21 * Modified by the GLib Team and others 1997-2000. See the AUTHORS
22 * file for a list of people on the GLib Team. See the ChangeLog
23 * files for a list of changes. These files are distributed with
24 * GLib at ftp://ftp.gtk.org/pub/gtk/.
25 */
26
27 #if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
28 #error "Only <glib.h> can be included directly."
29 #endif
30
31 #ifndef __G_THREAD_H__
32 #define __G_THREAD_H__
33
34 #include <glib/gerror.h>
35 #include <glib/gtypes.h>
36 #include <glib/gutils.h> /* for G_INLINE_FUNC */
37 #include <glib/gatomic.h> /* for g_atomic_pointer_get */
38
39 G_BEGIN_DECLS
40
41 /* GLib Thread support
42 */
43
44 extern GQuark g_thread_error_quark (void);
45 #define G_THREAD_ERROR g_thread_error_quark ()
46
47 typedef enum
48 {
49 G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
50 } GThreadError;
51
52 typedef gpointer (*GThreadFunc) (gpointer data);
53
54 typedef enum
55 {
56 G_THREAD_PRIORITY_LOW,
57 G_THREAD_PRIORITY_NORMAL,
58 G_THREAD_PRIORITY_HIGH,
59 G_THREAD_PRIORITY_URGENT
60 } GThreadPriority;
61
62 typedef struct _GThread GThread;
63 struct _GThread
64 {
65 /*< private >*/
66 GThreadFunc func;
67 gpointer data;
68 gboolean joinable;
69 GThreadPriority priority;
70 };
71
72 typedef struct _GMutex GMutex;
73 typedef struct _GCond GCond;
74 typedef struct _GPrivate GPrivate;
75 typedef struct _GStaticPrivate GStaticPrivate;
76
77 typedef struct _GThreadFunctions GThreadFunctions;
78 struct _GThreadFunctions
79 {
80 GMutex* (*mutex_new) (void);
81 void (*mutex_lock) (GMutex *mutex);
82 gboolean (*mutex_trylock) (GMutex *mutex);
83 void (*mutex_unlock) (GMutex *mutex);
84 void (*mutex_free) (GMutex *mutex);
85 GCond* (*cond_new) (void);
86 void (*cond_signal) (GCond *cond);
87 void (*cond_broadcast) (GCond *cond);
88 void (*cond_wait) (GCond *cond,
89 GMutex *mutex);
90 gboolean (*cond_timed_wait) (GCond *cond,
91 GMutex *mutex,
92 GTimeVal *end_time);
93 void (*cond_free) (GCond *cond);
94 GPrivate* (*private_new) (GDestroyNotify destructor);
95 gpointer (*private_get) (GPrivate *private_key);
96 void (*private_set) (GPrivate *private_key,
97 gpointer data);
98 void (*thread_create) (GThreadFunc func,
99 gpointer data,
100 gulong stack_size,
101 gboolean joinable,
102 gboolean bound,
103 GThreadPriority priority,
104 gpointer thread,
105 GError **error);
106 void (*thread_yield) (void);
107 void (*thread_join) (gpointer thread);
108 void (*thread_exit) (void);
109 void (*thread_set_priority)(gpointer thread,
110 GThreadPriority priority);
111 void (*thread_self) (gpointer thread);
112 gboolean (*thread_equal) (gpointer thread1,
113 gpointer thread2);
114 };
115
116 GLIB_VAR GThreadFunctions g_thread_functions_for_glib_use;
117 GLIB_VAR gboolean g_thread_use_default_impl;
118 GLIB_VAR gboolean g_threads_got_initialized;
119
120 GLIB_VAR guint64 (*g_thread_gettime) (void);
121
122 /* initializes the mutex/cond/private implementation for glib, might
123 * only be called once, and must not be called directly or indirectly
124 * from another glib-function, e.g. as a callback.
125 */
126 void g_thread_init (GThreadFunctions *vtable);
127
128 /* Errorcheck mutexes. If you define G_ERRORCHECK_MUTEXES, then all
129 * mutexes will check for re-locking and re-unlocking */
130
131 /* Initialize thread system with errorcheck mutexes. vtable must be
132 * NULL. Do not call directly. Use #define G_ERRORCHECK_MUTEXES
133 * instead.
134 */
135 void g_thread_init_with_errorcheck_mutexes (GThreadFunctions* vtable);
136
137 /* Checks if thread support is initialized. Identical to the
138 * g_thread_supported macro but provided for language bindings.
139 */
140 gboolean g_thread_get_initialized (void);
141
142 /* A random number to recognize debug calls to g_mutex_... */
143 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
144
145 #ifdef G_ERRORCHECK_MUTEXES
146 #define g_thread_init(vtable) g_thread_init_with_errorcheck_mutexes (vtable)
147 #endif
148
149 /* internal function for fallback static mutex implementation */
150 GMutex* g_static_mutex_get_mutex_impl (GMutex **mutex);
151
152 #define g_static_mutex_get_mutex_impl_shortcut(mutex) \
153 (g_atomic_pointer_get (mutex) ? *(mutex) : \
154 g_static_mutex_get_mutex_impl (mutex))
155
156 /* shorthands for conditional and unconditional function calls */
157
158 #define G_THREAD_UF(op, arglist) \
159 (*g_thread_functions_for_glib_use . op) arglist
160 #define G_THREAD_CF(op, fail, arg) \
161 (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
162 #define G_THREAD_ECF(op, fail, mutex, type) \
163 (g_thread_supported () ? \
164 ((type(*)(GMutex*, const gulong, gchar const*)) \
165 (*g_thread_functions_for_glib_use . op)) \
166 (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
167
168 #ifndef G_ERRORCHECK_MUTEXES
169 # define g_mutex_lock(mutex) \
170 G_THREAD_CF (mutex_lock, (void)0, (mutex))
171 # define g_mutex_trylock(mutex) \
172 G_THREAD_CF (mutex_trylock, TRUE, (mutex))
173 # define g_mutex_unlock(mutex) \
174 G_THREAD_CF (mutex_unlock, (void)0, (mutex))
175 # define g_mutex_free(mutex) \
176 G_THREAD_CF (mutex_free, (void)0, (mutex))
177 # define g_cond_wait(cond, mutex) \
178 G_THREAD_CF (cond_wait, (void)0, (cond, mutex))
179 # define g_cond_timed_wait(cond, mutex, abs_time) \
180 G_THREAD_CF (cond_timed_wait, TRUE, (cond, mutex, abs_time))
181 #else /* G_ERRORCHECK_MUTEXES */
182 # define g_mutex_lock(mutex) \
183 G_THREAD_ECF (mutex_lock, (void)0, (mutex), void)
184 # define g_mutex_trylock(mutex) \
185 G_THREAD_ECF (mutex_trylock, TRUE, (mutex), gboolean)
186 # define g_mutex_unlock(mutex) \
187 G_THREAD_ECF (mutex_unlock, (void)0, (mutex), void)
188 # define g_mutex_free(mutex) \
189 G_THREAD_ECF (mutex_free, (void)0, (mutex), void)
190 # define g_cond_wait(cond, mutex) \
191 (g_thread_supported () ? ((void(*)(GCond*, GMutex*, gulong, gchar*))\
192 g_thread_functions_for_glib_use.cond_wait) \
193 (cond, mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (void) 0)
194 # define g_cond_timed_wait(cond, mutex, abs_time) \
195 (g_thread_supported () ? \
196 ((gboolean(*)(GCond*, GMutex*, GTimeVal*, gulong, gchar*)) \
197 g_thread_functions_for_glib_use.cond_timed_wait) \
198 (cond, mutex, abs_time, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : TRUE)
199 #endif /* G_ERRORCHECK_MUTEXES */
200
201 #define g_thread_supported() (g_threads_got_initialized)
202 #define g_mutex_new() G_THREAD_UF (mutex_new, ())
203 #define g_cond_new() G_THREAD_UF (cond_new, ())
204 #define g_cond_signal(cond) G_THREAD_CF (cond_signal, (void)0, (cond))
205 #define g_cond_broadcast(cond) G_THREAD_CF (cond_broadcast, (void)0, (cond))
206 #define g_cond_free(cond) G_THREAD_CF (cond_free, (void)0, (cond))
207 #define g_private_new(destructor) G_THREAD_UF (private_new, (destructor))
208 #define g_private_get(private_key) G_THREAD_CF (private_get, \
209 ((gpointer)private_key), \
210 (private_key))
211 #define g_private_set(private_key, value) G_THREAD_CF (private_set, \
212 (void) (private_key = \
213 (GPrivate*) (value)), \
214 (private_key, value))
215 #define g_thread_yield() G_THREAD_CF (thread_yield, (void)0, ())
216
217 #define g_thread_create(func, data, joinable, error) \
218 (g_thread_create_full (func, data, 0, joinable, FALSE, \
219 G_THREAD_PRIORITY_NORMAL, error))
220
221 GThread* g_thread_create_full (GThreadFunc func,
222 gpointer data,
223 gulong stack_size,
224 gboolean joinable,
225 gboolean bound,
226 GThreadPriority priority,
227 GError **error);
228 GThread* g_thread_self (void);
229 void g_thread_exit (gpointer retval);
230 gpointer g_thread_join (GThread *thread);
231
232 void g_thread_set_priority (GThread *thread,
233 GThreadPriority priority);
234
235 /* GStaticMutexes can be statically initialized with the value
236 * G_STATIC_MUTEX_INIT, and then they can directly be used, that is
237 * much easier, than having to explicitly allocate the mutex before
238 * use
239 */
240 #define g_static_mutex_lock(mutex) \
241 g_mutex_lock (g_static_mutex_get_mutex (mutex))
242 #define g_static_mutex_trylock(mutex) \
243 g_mutex_trylock (g_static_mutex_get_mutex (mutex))
244 #define g_static_mutex_unlock(mutex) \
245 g_mutex_unlock (g_static_mutex_get_mutex (mutex))
246 void g_static_mutex_init (GStaticMutex *mutex);
247 void g_static_mutex_free (GStaticMutex *mutex);
248
249 struct _GStaticPrivate
250 {
251 /*< private >*/
252 guint index;
253 };
254 #define G_STATIC_PRIVATE_INIT { 0 }
255 void g_static_private_init (GStaticPrivate *private_key);
256 gpointer g_static_private_get (GStaticPrivate *private_key);
257 void g_static_private_set (GStaticPrivate *private_key,
258 gpointer data,
259 GDestroyNotify notify);
260 void g_static_private_free (GStaticPrivate *private_key);
261
262 typedef struct _GStaticRecMutex GStaticRecMutex;
263 struct _GStaticRecMutex
264 {
265 /*< private >*/
266 GStaticMutex mutex;
267 guint depth;
268 GSystemThread owner;
269 };
270
271 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT }
272 void g_static_rec_mutex_init (GStaticRecMutex *mutex);
273 void g_static_rec_mutex_lock (GStaticRecMutex *mutex);
274 gboolean g_static_rec_mutex_trylock (GStaticRecMutex *mutex);
275 void g_static_rec_mutex_unlock (GStaticRecMutex *mutex);
276 void g_static_rec_mutex_lock_full (GStaticRecMutex *mutex,
277 guint depth);
278 guint g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
279 void g_static_rec_mutex_free (GStaticRecMutex *mutex);
280
281 typedef struct _GStaticRWLock GStaticRWLock;
282 struct _GStaticRWLock
283 {
284 /*< private >*/
285 GStaticMutex mutex;
286 GCond *read_cond;
287 GCond *write_cond;
288 guint read_counter;
289 gboolean have_writer;
290 guint want_to_read;
291 guint want_to_write;
292 };
293
294 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, 0, 0 }
295
296 void g_static_rw_lock_init (GStaticRWLock* lock);
297 void g_static_rw_lock_reader_lock (GStaticRWLock* lock);
298 gboolean g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
299 void g_static_rw_lock_reader_unlock (GStaticRWLock* lock);
300 void g_static_rw_lock_writer_lock (GStaticRWLock* lock);
301 gboolean g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
302 void g_static_rw_lock_writer_unlock (GStaticRWLock* lock);
303 void g_static_rw_lock_free (GStaticRWLock* lock);
304
305 void g_thread_foreach (GFunc thread_func,
306 gpointer user_data);
307
308 typedef enum
309 {
310 G_ONCE_STATUS_NOTCALLED,
311 G_ONCE_STATUS_PROGRESS,
312 G_ONCE_STATUS_READY
313 } GOnceStatus;
314
315 typedef struct _GOnce GOnce;
316 struct _GOnce
317 {
318 volatile GOnceStatus status;
319 volatile gpointer retval;
320 };
321
322 #define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
323
324 gpointer g_once_impl (GOnce *once, GThreadFunc func, gpointer arg);
325
326 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
327 # define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
328 #else /* !G_ATOMIC_OP_MEMORY_BARRIER_NEEDED*/
329 # define g_once(once, func, arg) \
330 (((once)->status == G_ONCE_STATUS_READY) ? \
331 (once)->retval : \
332 g_once_impl ((once), (func), (arg)))
333 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
334
335 /* initialize-once guards, keyed by value_location */
336 G_INLINE_FUNC gboolean g_once_init_enter (volatile gsize *value_location);
337 gboolean g_once_init_enter_impl (volatile gsize *value_location);
338 void g_once_init_leave (volatile gsize *value_location,
339 gsize initialization_value);
340 #if defined (G_CAN_INLINE) || defined (__G_THREAD_C__)
341 G_INLINE_FUNC gboolean
g_once_init_enter(volatile gsize * value_location)342 g_once_init_enter (volatile gsize *value_location)
343 {
344 if G_LIKELY ((gpointer) g_atomic_pointer_get (value_location) != NULL)
345 return FALSE;
346 else
347 return g_once_init_enter_impl (value_location);
348 }
349 #endif /* G_CAN_INLINE || __G_THREAD_C__ */
350
351 /* these are some convenience macros that expand to nothing if GLib
352 * was configured with --disable-threads. for using StaticMutexes,
353 * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
354 * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
355 * declare such an globally defined lock. name is a unique identifier
356 * for the protected varibale or code portion. locking, testing and
357 * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
358 * G_TRYLOCK() respectively.
359 */
360 extern void glib_dummy_decl (void);
361 #define G_LOCK_NAME(name) g__ ## name ## _lock
362 #ifdef G_THREADS_ENABLED
363 # define G_LOCK_DEFINE_STATIC(name) static G_LOCK_DEFINE (name)
364 # define G_LOCK_DEFINE(name) \
365 GStaticMutex G_LOCK_NAME (name) = G_STATIC_MUTEX_INIT
366 # define G_LOCK_EXTERN(name) extern GStaticMutex G_LOCK_NAME (name)
367
368 # ifdef G_DEBUG_LOCKS
369 # define G_LOCK(name) G_STMT_START{ \
370 g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
371 "file %s: line %d (%s): locking: %s ", \
372 __FILE__, __LINE__, G_STRFUNC, \
373 #name); \
374 g_static_mutex_lock (&G_LOCK_NAME (name)); \
375 }G_STMT_END
376 # define G_UNLOCK(name) G_STMT_START{ \
377 g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
378 "file %s: line %d (%s): unlocking: %s ", \
379 __FILE__, __LINE__, G_STRFUNC, \
380 #name); \
381 g_static_mutex_unlock (&G_LOCK_NAME (name)); \
382 }G_STMT_END
383 # define G_TRYLOCK(name) \
384 (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG, \
385 "file %s: line %d (%s): try locking: %s ", \
386 __FILE__, __LINE__, G_STRFUNC, \
387 #name), g_static_mutex_trylock (&G_LOCK_NAME (name)))
388 # else /* !G_DEBUG_LOCKS */
389 # define G_LOCK(name) g_static_mutex_lock (&G_LOCK_NAME (name))
390 # define G_UNLOCK(name) g_static_mutex_unlock (&G_LOCK_NAME (name))
391 # define G_TRYLOCK(name) g_static_mutex_trylock (&G_LOCK_NAME (name))
392 # endif /* !G_DEBUG_LOCKS */
393 #else /* !G_THREADS_ENABLED */
394 # define G_LOCK_DEFINE_STATIC(name) extern void glib_dummy_decl (void)
395 # define G_LOCK_DEFINE(name) extern void glib_dummy_decl (void)
396 # define G_LOCK_EXTERN(name) extern void glib_dummy_decl (void)
397 # define G_LOCK(name)
398 # define G_UNLOCK(name)
399 # define G_TRYLOCK(name) (TRUE)
400 #endif /* !G_THREADS_ENABLED */
401
402 G_END_DECLS
403
404 #endif /* __G_THREAD_H__ */
405