gthread-posix.c revision b13320f78ba3b484a26b6430152b35aaac24ff10 
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 <pthread.h>
35#include <errno.h>
36#include <stdlib.h>
37#ifdef HAVE_SYS_TIME_H
38#include <sys/time.h>
39#endif
40#ifdef HAVE_UNISTD_H
41#include <unistd.h>
42#endif
43
44#define posix_check_err(err, name) G_STMT_START{			\
45  int error = (err); 							\
46  if (error)	 		 		 			\
47    g_error ("file %s: line %d (%s): error %s during %s",		\
48           __FILE__, __LINE__, G_GNUC_PRETTY_FUNCTION,			\
49           g_strerror (error), name);					\
50  }G_STMT_END
51
52#define posix_check_cmd(cmd) posix_check_err (posix_error (cmd), #cmd)
53
54#ifdef G_ENABLE_DEBUG
55static gboolean posix_check_cmd_prio_warned = FALSE;
56# define posix_check_cmd_prio(cmd) G_STMT_START{			\
57    int err = posix_error (cmd);					\
58    if (err == EPERM)		 		 			\
59      { 	 			 				\
60        if (!posix_check_cmd_prio_warned) 		 		\
61          { 	 				 			\
62            posix_check_cmd_prio_warned = TRUE;		 		\
63            g_warning ("Priorities can only be changed by root."); 	\
64          }			 					\
65      }			 						\
66    else  		 						\
67      posix_check_err (err, #cmd);					\
68     }G_STMT_END
69#else /* G_ENABLE_DEBUG */
70# define posix_check_cmd_prio(cmd) G_STMT_START{			\
71    int err = posix_error (cmd);					\
72    if (err != EPERM)		 		 			\
73      posix_check_err (err, #cmd);					\
74     }G_STMT_END
75#endif /* G_ENABLE_DEBUG */
76
77#if defined(G_THREADS_IMPL_POSIX)
78# define posix_error(what) (what)
79# define mutexattr_default NULL
80# define condattr_default NULL
81#elif defined(G_THREADS_IMPL_DCE)
82# define posix_error(what) ((what) == -1 ? errno : 0)
83# define pthread_key_create(a, b) pthread_keycreate (a, b)
84# define pthread_attr_init(a) pthread_attr_create (a)
85# define pthread_attr_destroy(a) pthread_attr_delete (a)
86# define pthread_create(a, b, c, d) pthread_create (a, *b, c, d)
87# define mutexattr_default (pthread_mutexattr_default)
88# define condattr_default (pthread_condattr_default)
89#else /* neither G_THREADS_IMPL_POSIX nor G_THREADS_IMPL_DCE are defined */
90# error This should not happen. Contact the GLib team.
91#endif
92
93#if defined (POSIX_MIN_PRIORITY) && defined (POSIX_MAX_PRIORITY)
94#  define HAVE_PRIORITIES 1
95#endif
96
97gulong g_thread_min_stack_size = 0;
98
99#define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
100
101#define HAVE_G_THREAD_IMPL_INIT
102static void
103g_thread_impl_init()
104{
105#ifdef HAVE_PRIORITIES
106  g_thread_min_priority = POSIX_MIN_PRIORITY;
107  g_thread_max_priority = POSIX_MAX_PRIORITY;
108#endif /* HAVE_PRIORITIES */
109#ifdef _SC_THREAD_STACK_MIN
110  g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
111#endif /* _SC_THREAD_STACK_MIN */
112}
113
114static GMutex *
115g_mutex_new_posix_impl (void)
116{
117  GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
118  posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
119				       mutexattr_default));
120  return result;
121}
122
123static void
124g_mutex_free_posix_impl (GMutex * mutex)
125{
126  posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
127  g_free (mutex);
128}
129
130/* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
131   functions from gmem.c and gmessages.c; */
132
133/* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
134   signature and semantic are right, but without error check then!!!!,
135   we might want to change this therefore. */
136
137static gboolean
138g_mutex_trylock_posix_impl (GMutex * mutex)
139{
140  int result;
141
142  result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
143
144#ifdef G_THREADS_IMPL_POSIX
145  if (result == EBUSY)
146    return FALSE;
147#else /* G_THREADS_IMPL_DCE */
148  if (result == 0)
149    return FALSE;
150#endif
151
152  posix_check_err (posix_error (result), "pthread_mutex_trylock");
153  return TRUE;
154}
155
156static GCond *
157g_cond_new_posix_impl (void)
158{
159  GCond *result = (GCond *) g_new (pthread_cond_t, 1);
160  posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
161				      condattr_default));
162  return result;
163}
164
165/* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
166   can be taken directly, as signature and semantic are right, but
167   without error check then!!!!, we might want to change this
168   therfore. */
169
170#define G_NSEC_PER_SEC 1000000000
171
172static gboolean
173g_cond_timed_wait_posix_impl (GCond * cond,
174			      GMutex * entered_mutex,
175			      GTimeVal * abs_time)
176{
177  int result;
178  struct timespec end_time;
179  gboolean timed_out;
180
181  g_return_val_if_fail (cond != NULL, FALSE);
182  g_return_val_if_fail (entered_mutex != NULL, FALSE);
183
184  if (!abs_time)
185    {
186      g_cond_wait (cond, entered_mutex);
187      return TRUE;
188    }
189
190  end_time.tv_sec = abs_time->tv_sec;
191  end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
192  g_assert (end_time.tv_nsec < G_NSEC_PER_SEC);
193  result = pthread_cond_timedwait ((pthread_cond_t *) cond,
194				   (pthread_mutex_t *) entered_mutex,
195				   &end_time);
196
197#ifdef G_THREADS_IMPL_POSIX
198  timed_out = (result == ETIMEDOUT);
199#else /* G_THREADS_IMPL_DCE */
200  timed_out = (result == -1) && (errno = EAGAIN);
201#endif
202
203  if (!timed_out)
204    posix_check_err (posix_error (result), "pthread_cond_timedwait");
205  return !timed_out;
206}
207
208static void
209g_cond_free_posix_impl (GCond * cond)
210{
211  posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
212  g_free (cond);
213}
214
215static GPrivate *
216g_private_new_posix_impl (GDestroyNotify destructor)
217{
218  GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
219  posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
220  return result;
221}
222
223/* NOTE: the functions g_private_get and g_private_set may not use
224   functions from gmem.c and gmessages.c */
225
226static void
227g_private_set_posix_impl (GPrivate * private_key, gpointer value)
228{
229  if (!private_key)
230    return;
231  pthread_setspecific (*(pthread_key_t *) private_key, value);
232}
233
234static gpointer
235g_private_get_posix_impl (GPrivate * private_key)
236{
237  if (!private_key)
238    return NULL;
239#ifdef G_THREADS_IMPL_POSIX
240  return pthread_getspecific (*(pthread_key_t *) private_key);
241#else /* G_THREADS_IMPL_DCE */
242  {
243    void* data;
244    posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
245					  &data));
246    return data;
247  }
248#endif
249}
250
251static void
252g_thread_create_posix_impl (GThreadFunc thread_func,
253			    gpointer arg,
254			    gulong stack_size,
255			    gboolean joinable,
256			    gboolean bound,
257			    GThreadPriority priority,
258			    gpointer thread,
259			    GError **error)
260{
261  pthread_attr_t attr;
262  gint ret;
263
264  g_return_if_fail (thread_func);
265
266  posix_check_cmd (pthread_attr_init (&attr));
267
268#ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
269  if (stack_size)
270    {
271      stack_size = MAX (g_thread_min_stack_size, stack_size);
272      posix_check_cmd (pthread_attr_setstacksize (&attr, stack_size));
273    }
274#endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
275
276#ifdef PTHREAD_SCOPE_SYSTEM
277  if (bound)
278    /* No error check here, because some systems can't do it and we
279     * simply don't want threads to fail because of that. */
280    pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
281#endif /* PTHREAD_SCOPE_SYSTEM */
282
283#ifdef G_THREADS_IMPL_POSIX
284  posix_check_cmd (pthread_attr_setdetachstate (&attr,
285          joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
286#endif /* G_THREADS_IMPL_POSIX */
287
288#ifdef HAVE_PRIORITIES
289# ifdef G_THREADS_IMPL_POSIX
290  {
291    struct sched_param sched;
292    posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
293    sched.sched_priority = g_thread_map_priority (priority);
294    posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
295  }
296# else /* G_THREADS_IMPL_DCE */
297  posix_check_cmd_prio
298    (pthread_attr_setprio (&attr, g_thread_map_priority (priority)));
299# endif /* G_THREADS_IMPL_DCE */
300#endif /* HAVE_PRIORITIES */
301
302  ret = posix_error (pthread_create (thread, &attr,
303				     (void* (*)(void*))thread_func, arg));
304
305  posix_check_cmd (pthread_attr_destroy (&attr));
306
307  if (ret == EAGAIN)
308    {
309      g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
310		   "Error creating thread: %s", g_strerror (ret));
311      return;
312    }
313
314  posix_check_err (ret, "pthread_create");
315
316#ifdef G_THREADS_IMPL_DCE
317  if (!joinable)
318    posix_check_cmd (pthread_detach (thread));
319#endif /* G_THREADS_IMPL_DCE */
320}
321
322static void
323g_thread_yield_posix_impl (void)
324{
325  POSIX_YIELD_FUNC;
326}
327
328static void
329g_thread_join_posix_impl (gpointer thread)
330{
331  gpointer ignore;
332  posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
333}
334
335static void
336g_thread_exit_posix_impl (void)
337{
338  pthread_exit (NULL);
339}
340
341static void
342g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
343{
344#ifdef HAVE_PRIORITIES
345# ifdef G_THREADS_IMPL_POSIX
346  struct sched_param sched;
347  int policy;
348  posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
349					  &sched));
350  sched.sched_priority = g_thread_map_priority (priority);
351  posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
352					       &sched));
353# else /* G_THREADS_IMPL_DCE */
354  posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
355					 g_thread_map_priority (priority)));
356# endif
357#endif /* HAVE_PRIORITIES */
358}
359
360static void
361g_thread_self_posix_impl (gpointer thread)
362{
363  *(pthread_t*)thread = pthread_self();
364}
365
366static GThreadFunctions g_thread_functions_for_glib_use_default =
367{
368  g_mutex_new_posix_impl,
369  (void (*)(GMutex *)) pthread_mutex_lock,
370  g_mutex_trylock_posix_impl,
371  (void (*)(GMutex *)) pthread_mutex_unlock,
372  g_mutex_free_posix_impl,
373  g_cond_new_posix_impl,
374  (void (*)(GCond *)) pthread_cond_signal,
375  (void (*)(GCond *)) pthread_cond_broadcast,
376  (void (*)(GCond *, GMutex *)) pthread_cond_wait,
377  g_cond_timed_wait_posix_impl,
378  g_cond_free_posix_impl,
379  g_private_new_posix_impl,
380  g_private_get_posix_impl,
381  g_private_set_posix_impl,
382  g_thread_create_posix_impl,
383  g_thread_yield_posix_impl,
384  g_thread_join_posix_impl,
385  g_thread_exit_posix_impl,
386  g_thread_set_priority_posix_impl,
387  g_thread_self_posix_impl
388};
389