gthread/gthread-posix.c

   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 #ifdef HAVE_SCHED_H
  45 #include <sched.h>
  46 #endif
  47
  48 #define posix_check_err(err, name) G_STMT_START{                        \
  49   int error = (err);                                                    \
  50   if (error)                                                            \
  51     g_error ("file %s: line %d (%s): error '%s' during '%s'",           \
  52            __FILE__, __LINE__, G_GNUC_PRETTY_FUNCTION,                  \
  53            g_strerror (error), name);                                   \
  54   }G_STMT_END
  55
  56 #define posix_check_cmd(cmd) posix_check_err (posix_error (cmd), #cmd)
  57
  58 #ifdef G_ENABLE_DEBUG
  59 static gboolean posix_check_cmd_prio_warned = FALSE;
  60 # define posix_check_cmd_prio(cmd) G_STMT_START{                        \
  61     int err = posix_error (cmd);                                        \
  62     if (err == EPERM)                                                   \
  63       {                                                                 \
  64         if (!posix_check_cmd_prio_warned)                               \
  65           {                                                             \
  66             posix_check_cmd_prio_warned = TRUE;                         \
  67             g_warning ("Priorities can only be changed "                \
  68                         "(resp. increased) by root.");                  \
  69           }                                                             \
  70       }                                                                 \
  71     else                                                                \
  72       posix_check_err (err, #cmd);                                      \
  73      }G_STMT_END
  74 #else /* G_ENABLE_DEBUG */
  75 # define posix_check_cmd_prio(cmd) G_STMT_START{                        \
  76     int err = posix_error (cmd);                                        \
  77     if (err != EPERM)                                                   \
  78       posix_check_err (err, #cmd);                                      \
  79      }G_STMT_END
  80 #endif /* G_ENABLE_DEBUG */
  81
  82 #if defined(G_THREADS_IMPL_POSIX)
  83 # define posix_error(what) (what)
  84 # define mutexattr_default NULL
  85 # define condattr_default NULL
  86 #elif defined(G_THREADS_IMPL_DCE)
  87 # define posix_error(what) ((what) == -1 ? errno : 0)
  88 # define pthread_key_create(a, b) pthread_keycreate (a, b)
  89 # define pthread_attr_init(a) pthread_attr_create (a)
  90 # define pthread_attr_destroy(a) pthread_attr_delete (a)
  91 # define pthread_create(a, b, c, d) pthread_create (a, *b, c, d)
  92 # define mutexattr_default (pthread_mutexattr_default)
  93 # define condattr_default (pthread_condattr_default)
  94 #else /* neither G_THREADS_IMPL_POSIX nor G_THREADS_IMPL_DCE are defined */
  95 # error This should not happen. Contact the GLib team.
  96 #endif
  97
  98 #if defined (POSIX_MIN_PRIORITY) && defined (POSIX_MAX_PRIORITY)
  99 # define HAVE_PRIORITIES 1
 100 # define PRIORITY_LOW_VALUE POSIX_MIN_PRIORITY
 101 # define PRIORITY_URGENT_VALUE POSIX_MAX_PRIORITY
 102 #endif /* POSIX_MIN_PRIORITY && POSIX_MAX_PRIORITY */
 103
 104 static gulong g_thread_min_stack_size = 0;
 105
 106 #define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
 107
 108 #ifdef _SC_THREAD_STACK_MIN
 109 #define HAVE_G_THREAD_IMPL_INIT
 110 static void
 111 g_thread_impl_init()
 112 {
 113   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
 114 }
 115 #endif /* _SC_THREAD_STACK_MIN */
 116
 117 static GMutex *
 118 g_mutex_new_posix_impl (void)
 119 {
 120   GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
 121   posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
 122                                        mutexattr_default));
 123   return result;
 124 }
 125
 126 static void
 127 g_mutex_free_posix_impl (GMutex * mutex)
 128 {
 129   posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
 130   g_free (mutex);
 131 }
 132
 133 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
 134    functions from gmem.c and gmessages.c; */
 135
 136 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
 137    signature and semantic are right, but without error check then!!!!,
 138    we might want to change this therefore. */
 139
 140 static gboolean
 141 g_mutex_trylock_posix_impl (GMutex * mutex)
 142 {
 143   int result;
 144
 145   result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
 146
 147 #ifdef G_THREADS_IMPL_POSIX
 148   if (result == EBUSY)
 149     return FALSE;
 150 #else /* G_THREADS_IMPL_DCE */
 151   if (result == 0)
 152     return FALSE;
 153 #endif
 154
 155   posix_check_err (posix_error (result), "pthread_mutex_trylock");
 156   return TRUE;
 157 }
 158
 159 static GCond *
 160 g_cond_new_posix_impl (void)
 161 {
 162   GCond *result = (GCond *) g_new (pthread_cond_t, 1);
 163   posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
 164                                       condattr_default));
 165   return result;
 166 }
 167
 168 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
 169    can be taken directly, as signature and semantic are right, but
 170    without error check then!!!!, we might want to change this
 171    therfore. */
 172
 173 #define G_NSEC_PER_SEC 1000000000
 174
 175 static gboolean
 176 g_cond_timed_wait_posix_impl (GCond * cond,
 177                               GMutex * entered_mutex,
 178                               GTimeVal * abs_time)
 179 {
 180   int result;
 181   struct timespec end_time;
 182   gboolean timed_out;
 183
 184   g_return_val_if_fail (cond != NULL, FALSE);
 185   g_return_val_if_fail (entered_mutex != NULL, FALSE);
 186
 187   if (!abs_time)
 188     {
 189       g_cond_wait (cond, entered_mutex);
 190       return TRUE;
 191     }
 192
 193   end_time.tv_sec = abs_time->tv_sec;
 194   end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 195   g_assert (end_time.tv_nsec < G_NSEC_PER_SEC);
 196   result = pthread_cond_timedwait ((pthread_cond_t *) cond,
 197                                    (pthread_mutex_t *) entered_mutex,
 198                                    &end_time);
 199
 200 #ifdef G_THREADS_IMPL_POSIX
 201   timed_out = (result == ETIMEDOUT);
 202 #else /* G_THREADS_IMPL_DCE */
 203   timed_out = (result == -1) && (errno = EAGAIN);
 204 #endif
 205
 206   if (!timed_out)
 207     posix_check_err (posix_error (result), "pthread_cond_timedwait");
 208   return !timed_out;
 209 }
 210
 211 static void
 212 g_cond_free_posix_impl (GCond * cond)
 213 {
 214   posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
 215   g_free (cond);
 216 }
 217
 218 static GPrivate *
 219 g_private_new_posix_impl (GDestroyNotify destructor)
 220 {
 221   GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
 222   posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
 223   return result;
 224 }
 225
 226 /* NOTE: the functions g_private_get and g_private_set may not use
 227    functions from gmem.c and gmessages.c */
 228
 229 static void
 230 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
 231 {
 232   if (!private_key)
 233     return;
 234   pthread_setspecific (*(pthread_key_t *) private_key, value);
 235 }
 236
 237 static gpointer
 238 g_private_get_posix_impl (GPrivate * private_key)
 239 {
 240   if (!private_key)
 241     return NULL;
 242 #ifdef G_THREADS_IMPL_POSIX
 243   return pthread_getspecific (*(pthread_key_t *) private_key);
 244 #else /* G_THREADS_IMPL_DCE */
 245   {
 246     void* data;
 247     posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
 248                                           &data));
 249     return data;
 250   }
 251 #endif
 252 }
 253
 254 static void
 255 g_thread_create_posix_impl (GThreadFunc thread_func,
 256                             gpointer arg,
 257                             gulong stack_size,
 258                             gboolean joinable,
 259                             gboolean bound,
 260                             GThreadPriority priority,
 261                             gpointer thread,
 262                             GError **error)
 263 {
 264   pthread_attr_t attr;
 265   gint ret;
 266
 267   g_return_if_fail (thread_func);
 268   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 269   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 270
 271   posix_check_cmd (pthread_attr_init (&attr));
 272
 273 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 274   if (stack_size)
 275     {
 276       stack_size = MAX (g_thread_min_stack_size, stack_size);
 277       posix_check_cmd (pthread_attr_setstacksize (&attr, stack_size));
 278     }
 279 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 280
 281 #ifdef PTHREAD_SCOPE_SYSTEM
 282   if (bound)
 283     /* No error check here, because some systems can't do it and we
 284      * simply don't want threads to fail because of that. */
 285     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 286 #endif /* PTHREAD_SCOPE_SYSTEM */
 287
 288 #ifdef G_THREADS_IMPL_POSIX
 289   posix_check_cmd (pthread_attr_setdetachstate (&attr,
 290           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 291 #endif /* G_THREADS_IMPL_POSIX */
 292
 293 #ifdef HAVE_PRIORITIES
 294 # ifdef G_THREADS_IMPL_POSIX
 295   {
 296     struct sched_param sched;
 297     posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
 298     sched.sched_priority = g_thread_priority_map [priority];
 299     posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
 300   }
 301 # else /* G_THREADS_IMPL_DCE */
 302   posix_check_cmd_prio
 303     (pthread_attr_setprio (&attr, g_thread_priority_map [priority]));
 304 # endif /* G_THREADS_IMPL_DCE */
 305 #endif /* HAVE_PRIORITIES */
 306   ret = posix_error (pthread_create (thread, &attr,
 307                                      (void* (*)(void*))thread_func, arg));
 308
 309   posix_check_cmd (pthread_attr_destroy (&attr));
 310
 311   if (ret == EAGAIN)
 312     {
 313       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 314                    "Error creating thread: %s", g_strerror (ret));
 315       return;
 316     }
 317
 318   posix_check_err (ret, "pthread_create");
 319
 320 #ifdef G_THREADS_IMPL_DCE
 321   if (!joinable)
 322     posix_check_cmd (pthread_detach (thread));
 323 #endif /* G_THREADS_IMPL_DCE */
 324 }
 325
 326 static void
 327 g_thread_yield_posix_impl (void)
 328 {
 329   POSIX_YIELD_FUNC;
 330 }
 331
 332 static void
 333 g_thread_join_posix_impl (gpointer thread)
 334 {
 335   gpointer ignore;
 336   posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
 337 }
 338
 339 static void
 340 g_thread_exit_posix_impl (void)
 341 {
 342   pthread_exit (NULL);
 343 }
 344
 345 static void
 346 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 347 {
 348   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 349   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 350 #ifdef HAVE_PRIORITIES
 351 # ifdef G_THREADS_IMPL_POSIX
 352   {
 353     struct sched_param sched;
 354     int policy;
 355     posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
 356                                             &sched));
 357     sched.sched_priority = g_thread_priority_map [priority];
 358     posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
 359                                                  &sched));
 360   }
 361 # else /* G_THREADS_IMPL_DCE */
 362   posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
 363                                          g_thread_priority_map [priority]));
 364 # endif
 365 #endif /* HAVE_PRIORITIES */
 366 }
 367
 368 static void
 369 g_thread_self_posix_impl (gpointer thread)
 370 {
 371   *(pthread_t*)thread = pthread_self();
 372 }
 373
 374 static GThreadFunctions g_thread_functions_for_glib_use_default =
 375 {
 376   g_mutex_new_posix_impl,
 377   (void (*)(GMutex *)) pthread_mutex_lock,
 378   g_mutex_trylock_posix_impl,
 379   (void (*)(GMutex *)) pthread_mutex_unlock,
 380   g_mutex_free_posix_impl,
 381   g_cond_new_posix_impl,
 382   (void (*)(GCond *)) pthread_cond_signal,
 383   (void (*)(GCond *)) pthread_cond_broadcast,
 384   (void (*)(GCond *, GMutex *)) pthread_cond_wait,
 385   g_cond_timed_wait_posix_impl,
 386   g_cond_free_posix_impl,
 387   g_private_new_posix_impl,
 388   g_private_get_posix_impl,
 389   g_private_set_posix_impl,
 390   g_thread_create_posix_impl,
 391   g_thread_yield_posix_impl,
 392   g_thread_join_posix_impl,
 393   g_thread_exit_posix_impl,
 394   g_thread_set_priority_posix_impl,
 395   g_thread_self_posix_impl
 396 };