• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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