1 /* GLIB - Library of useful routines for C programming
2 * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
3 *
4 * gthread.c: posix thread system implementation
5 * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
6 *
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.
11 *
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.
16 *
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.
21 */
22
23 /*
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/.
28 */
29
30 /*
31 * MT safe
32 */
33
34 #include "config.h"
35
36 #include <pthread.h>
37 #include <errno.h>
38 #include <stdlib.h>
39 #ifdef HAVE_SYS_TIME_H
40 # include <sys/time.h>
41 #endif
42 #ifdef HAVE_UNISTD_H
43 # include <unistd.h>
44 #endif
45
46 #ifdef HAVE_SCHED_H
47 #include <sched.h>
48 #endif
49
50 #define posix_check_err(err, name) G_STMT_START{ \
51 int error = (err); \
52 if (error) \
53 g_error ("file %s: line %d (%s): error '%s' during '%s'", \
54 __FILE__, __LINE__, G_STRFUNC, \
55 g_strerror (error), name); \
56 }G_STMT_END
57
58 #define posix_check_cmd(cmd) posix_check_err (posix_error (cmd), #cmd)
59
60 #ifdef G_ENABLE_DEBUG
61 static gboolean posix_check_cmd_prio_warned = FALSE;
62 # define posix_check_cmd_prio(cmd) G_STMT_START{ \
63 int err = posix_error (cmd); \
64 if (err == EPERM) \
65 { \
66 if (!posix_check_cmd_prio_warned) \
67 { \
68 posix_check_cmd_prio_warned = TRUE; \
69 g_warning ("Priorities can only be changed " \
70 "(resp. increased) by root."); \
71 } \
72 } \
73 else \
74 posix_check_err (err, #cmd); \
75 }G_STMT_END
76 #else /* G_ENABLE_DEBUG */
77 # define posix_check_cmd_prio(cmd) G_STMT_START{ \
78 int err = posix_error (cmd); \
79 if (err != EPERM) \
80 posix_check_err (err, #cmd); \
81 }G_STMT_END
82 #endif /* G_ENABLE_DEBUG */
83
84 #if defined(G_THREADS_IMPL_POSIX)
85 # define posix_error(what) (what)
86 # define mutexattr_default NULL
87 # define condattr_default NULL
88 #elif defined(G_THREADS_IMPL_DCE)
89 # define posix_error(what) ((what) == -1 ? errno : 0)
90 # define pthread_key_create(a, b) pthread_keycreate (a, b)
91 # define pthread_attr_init(a) pthread_attr_create (a)
92 # define pthread_attr_destroy(a) pthread_attr_delete (a)
93 # define pthread_create(a, b, c, d) pthread_create (a, *b, c, d)
94 # define mutexattr_default (pthread_mutexattr_default)
95 # define condattr_default (pthread_condattr_default)
96 #else /* neither G_THREADS_IMPL_POSIX nor G_THREADS_IMPL_DCE are defined */
97 # error This should not happen. Contact the GLib team.
98 #endif
99
100 #if defined (POSIX_MIN_PRIORITY) && defined (POSIX_MAX_PRIORITY)
101 # define HAVE_PRIORITIES 1
102 static gint priority_normal_value;
103 # ifdef __FreeBSD__
104 /* FreeBSD threads use different priority values from the POSIX_
105 * defines so we just set them here. The corresponding macros
106 * PTHREAD_MIN_PRIORITY and PTHREAD_MAX_PRIORITY are implied to be
107 * exported by the docs, but they aren't.
108 */
109 # define PRIORITY_LOW_VALUE 0
110 # define PRIORITY_URGENT_VALUE 31
111 # else /* !__FreeBSD__ */
112 # define PRIORITY_LOW_VALUE POSIX_MIN_PRIORITY
113 # define PRIORITY_URGENT_VALUE POSIX_MAX_PRIORITY
114 # endif /* !__FreeBSD__ */
115 # define PRIORITY_NORMAL_VALUE priority_normal_value
116 #endif /* POSIX_MIN_PRIORITY && POSIX_MAX_PRIORITY */
117
118 static gulong g_thread_min_stack_size = 0;
119
120 #define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
121
122 #if defined(HAVE_CLOCK_GETTIME) && defined(HAVE_MONOTONIC_CLOCK)
123 #define USE_CLOCK_GETTIME 1
124 static gint posix_clock = 0;
125 #endif
126
127 #if defined(_SC_THREAD_STACK_MIN) || defined (HAVE_PRIORITIES) || defined (USE_CLOCK_GETTIME)
128 #define HAVE_G_THREAD_IMPL_INIT
129 static void
g_thread_impl_init(void)130 g_thread_impl_init(void)
131 {
132 #ifdef _SC_THREAD_STACK_MIN
133 g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
134 #endif /* _SC_THREAD_STACK_MIN */
135 #ifdef HAVE_PRIORITIES
136 # ifdef G_THREADS_IMPL_POSIX
137 {
138 struct sched_param sched;
139 int policy;
140 posix_check_cmd (pthread_getschedparam (pthread_self(), &policy, &sched));
141 priority_normal_value = sched.sched_priority;
142 }
143 # else /* G_THREADS_IMPL_DCE */
144 posix_check_cmd (priority_normal_value =
145 pthread_getprio (*(pthread_t*)thread,
146 g_thread_priority_map [priority]));
147 # endif
148 #endif /* HAVE_PRIORITIES */
149
150 #ifdef USE_CLOCK_GETTIME
151 if (sysconf (_SC_MONOTONIC_CLOCK) >= 0)
152 posix_clock = CLOCK_MONOTONIC;
153 else
154 posix_clock = CLOCK_REALTIME;
155 #endif
156 }
157 #endif /* _SC_THREAD_STACK_MIN || HAVE_PRIORITIES */
158
159 static GMutex *
g_mutex_new_posix_impl(void)160 g_mutex_new_posix_impl (void)
161 {
162 GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
163 posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
164 mutexattr_default));
165 return result;
166 }
167
168 static void
g_mutex_free_posix_impl(GMutex * mutex)169 g_mutex_free_posix_impl (GMutex * mutex)
170 {
171 posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
172 g_free (mutex);
173 }
174
175 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
176 functions from gmem.c and gmessages.c; */
177
178 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
179 signature and semantic are right, but without error check then!!!!,
180 we might want to change this therefore. */
181
182 static gboolean
g_mutex_trylock_posix_impl(GMutex * mutex)183 g_mutex_trylock_posix_impl (GMutex * mutex)
184 {
185 int result;
186
187 result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
188
189 #ifdef G_THREADS_IMPL_POSIX
190 if (result == EBUSY)
191 return FALSE;
192 #else /* G_THREADS_IMPL_DCE */
193 if (result == 0)
194 return FALSE;
195 #endif
196
197 posix_check_err (posix_error (result), "pthread_mutex_trylock");
198 return TRUE;
199 }
200
201 static GCond *
g_cond_new_posix_impl(void)202 g_cond_new_posix_impl (void)
203 {
204 GCond *result = (GCond *) g_new (pthread_cond_t, 1);
205 posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
206 condattr_default));
207 return result;
208 }
209
210 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
211 can be taken directly, as signature and semantic are right, but
212 without error check then!!!!, we might want to change this
213 therefore. */
214
215 #define G_NSEC_PER_SEC 1000000000
216
217 static gboolean
g_cond_timed_wait_posix_impl(GCond * cond,GMutex * entered_mutex,GTimeVal * abs_time)218 g_cond_timed_wait_posix_impl (GCond * cond,
219 GMutex * entered_mutex,
220 GTimeVal * abs_time)
221 {
222 int result;
223 struct timespec end_time;
224 gboolean timed_out;
225
226 g_return_val_if_fail (cond != NULL, FALSE);
227 g_return_val_if_fail (entered_mutex != NULL, FALSE);
228
229 if (!abs_time)
230 {
231 result = pthread_cond_wait ((pthread_cond_t *)cond,
232 (pthread_mutex_t *) entered_mutex);
233 timed_out = FALSE;
234 }
235 else
236 {
237 end_time.tv_sec = abs_time->tv_sec;
238 end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
239
240 g_return_val_if_fail (end_time.tv_nsec < G_NSEC_PER_SEC, TRUE);
241
242 result = pthread_cond_timedwait ((pthread_cond_t *) cond,
243 (pthread_mutex_t *) entered_mutex,
244 &end_time);
245 #ifdef G_THREADS_IMPL_POSIX
246 timed_out = (result == ETIMEDOUT);
247 #else /* G_THREADS_IMPL_DCE */
248 timed_out = (result == -1) && (errno == EAGAIN);
249 #endif
250 }
251
252 if (!timed_out)
253 posix_check_err (posix_error (result), "pthread_cond_timedwait");
254
255 return !timed_out;
256 }
257
258 static void
g_cond_free_posix_impl(GCond * cond)259 g_cond_free_posix_impl (GCond * cond)
260 {
261 posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
262 g_free (cond);
263 }
264
265 static GPrivate *
g_private_new_posix_impl(GDestroyNotify destructor)266 g_private_new_posix_impl (GDestroyNotify destructor)
267 {
268 GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
269 posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
270 return result;
271 }
272
273 /* NOTE: the functions g_private_get and g_private_set may not use
274 functions from gmem.c and gmessages.c */
275
276 static void
g_private_set_posix_impl(GPrivate * private_key,gpointer value)277 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
278 {
279 if (!private_key)
280 return;
281 pthread_setspecific (*(pthread_key_t *) private_key, value);
282 }
283
284 static gpointer
g_private_get_posix_impl(GPrivate * private_key)285 g_private_get_posix_impl (GPrivate * private_key)
286 {
287 if (!private_key)
288 return NULL;
289 #ifdef G_THREADS_IMPL_POSIX
290 return pthread_getspecific (*(pthread_key_t *) private_key);
291 #else /* G_THREADS_IMPL_DCE */
292 {
293 void* data;
294 posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
295 &data));
296 return data;
297 }
298 #endif
299 }
300
301 static void
g_thread_create_posix_impl(GThreadFunc thread_func,gpointer arg,gulong stack_size,gboolean joinable,gboolean bound,GThreadPriority priority,gpointer thread,GError ** error)302 g_thread_create_posix_impl (GThreadFunc thread_func,
303 gpointer arg,
304 gulong stack_size,
305 gboolean joinable,
306 gboolean bound,
307 GThreadPriority priority,
308 gpointer thread,
309 GError **error)
310 {
311 pthread_attr_t attr;
312 gint ret;
313
314 g_return_if_fail (thread_func);
315 g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
316 g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
317
318 posix_check_cmd (pthread_attr_init (&attr));
319
320 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
321 if (stack_size)
322 {
323 stack_size = MAX (g_thread_min_stack_size, stack_size);
324 /* No error check here, because some systems can't do it and
325 * we simply don't want threads to fail because of that. */
326 pthread_attr_setstacksize (&attr, stack_size);
327 }
328 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
329
330 #ifdef PTHREAD_SCOPE_SYSTEM
331 if (bound)
332 /* No error check here, because some systems can't do it and we
333 * simply don't want threads to fail because of that. */
334 pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
335 #endif /* PTHREAD_SCOPE_SYSTEM */
336
337 #ifdef G_THREADS_IMPL_POSIX
338 posix_check_cmd (pthread_attr_setdetachstate (&attr,
339 joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
340 #endif /* G_THREADS_IMPL_POSIX */
341
342 #ifdef HAVE_PRIORITIES
343 # ifdef G_THREADS_IMPL_POSIX
344 {
345 struct sched_param sched;
346 posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
347 sched.sched_priority = g_thread_priority_map [priority];
348 posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
349 }
350 # else /* G_THREADS_IMPL_DCE */
351 posix_check_cmd_prio
352 (pthread_attr_setprio (&attr, g_thread_priority_map [priority]));
353 # endif /* G_THREADS_IMPL_DCE */
354 #endif /* HAVE_PRIORITIES */
355 ret = posix_error (pthread_create (thread, &attr,
356 (void* (*)(void*))thread_func, arg));
357
358 posix_check_cmd (pthread_attr_destroy (&attr));
359
360 if (ret == EAGAIN)
361 {
362 g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
363 "Error creating thread: %s", g_strerror (ret));
364 return;
365 }
366
367 posix_check_err (ret, "pthread_create");
368
369 #ifdef G_THREADS_IMPL_DCE
370 if (!joinable)
371 posix_check_cmd (pthread_detach (thread));
372 #endif /* G_THREADS_IMPL_DCE */
373 }
374
375 static void
g_thread_yield_posix_impl(void)376 g_thread_yield_posix_impl (void)
377 {
378 POSIX_YIELD_FUNC;
379 }
380
381 static void
g_thread_join_posix_impl(gpointer thread)382 g_thread_join_posix_impl (gpointer thread)
383 {
384 gpointer ignore;
385 posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
386 }
387
388 static void
g_thread_exit_posix_impl(void)389 g_thread_exit_posix_impl (void)
390 {
391 pthread_exit (NULL);
392 }
393
394 static void
g_thread_set_priority_posix_impl(gpointer thread,GThreadPriority priority)395 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
396 {
397 g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
398 g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
399 #ifdef HAVE_PRIORITIES
400 # ifdef G_THREADS_IMPL_POSIX
401 {
402 struct sched_param sched;
403 int policy;
404 posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
405 &sched));
406 sched.sched_priority = g_thread_priority_map [priority];
407 posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
408 &sched));
409 }
410 # else /* G_THREADS_IMPL_DCE */
411 posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
412 g_thread_priority_map [priority]));
413 # endif
414 #endif /* HAVE_PRIORITIES */
415 }
416
417 static void
g_thread_self_posix_impl(gpointer thread)418 g_thread_self_posix_impl (gpointer thread)
419 {
420 *(pthread_t*)thread = pthread_self();
421 }
422
423 static gboolean
g_thread_equal_posix_impl(gpointer thread1,gpointer thread2)424 g_thread_equal_posix_impl (gpointer thread1, gpointer thread2)
425 {
426 return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
427 }
428
429 #ifdef USE_CLOCK_GETTIME
430 static guint64
gettime(void)431 gettime (void)
432 {
433 struct timespec tv;
434
435 clock_gettime (posix_clock, &tv);
436
437 return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_nsec;
438 }
439 static guint64 (*g_thread_gettime_impl)(void) = gettime;
440 #else
441 static guint64 (*g_thread_gettime_impl)(void) = 0;
442 #endif
443
444 static GThreadFunctions g_thread_functions_for_glib_use_default =
445 {
446 g_mutex_new_posix_impl,
447 (void (*)(GMutex *)) pthread_mutex_lock,
448 g_mutex_trylock_posix_impl,
449 (void (*)(GMutex *)) pthread_mutex_unlock,
450 g_mutex_free_posix_impl,
451 g_cond_new_posix_impl,
452 (void (*)(GCond *)) pthread_cond_signal,
453 (void (*)(GCond *)) pthread_cond_broadcast,
454 (void (*)(GCond *, GMutex *)) pthread_cond_wait,
455 g_cond_timed_wait_posix_impl,
456 g_cond_free_posix_impl,
457 g_private_new_posix_impl,
458 g_private_get_posix_impl,
459 g_private_set_posix_impl,
460 g_thread_create_posix_impl,
461 g_thread_yield_posix_impl,
462 g_thread_join_posix_impl,
463 g_thread_exit_posix_impl,
464 g_thread_set_priority_posix_impl,
465 g_thread_self_posix_impl,
466 g_thread_equal_posix_impl
467 };
468