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