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 G_MUTEX_SIZE (sizeof (pthread_mutex_t))
  77
  78 #define HAVE_G_THREAD_IMPL_INIT
  79 static void
  80 g_thread_impl_init()
  81 {
  82 #ifdef HAVE_PRIORITIES
  83   g_thread_min_priority = POSIX_MIN_PRIORITY;
  84   g_thread_max_priority = POSIX_MAX_PRIORITY;
  85 #endif /* HAVE_PRIORITIES */
  86 #ifdef _SC_THREAD_STACK_MIN
  87   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
  88 #endif /* _SC_THREAD_STACK_MIN */
  89 }
  90
  91 static GMutex *
  92 g_mutex_new_posix_impl (void)
  93 {
  94   GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
  95   posix_check_for_error (pthread_mutex_init ((pthread_mutex_t *) result,
  96                                              mutexattr_default));
  97   return result;
  98 }
  99
 100 static void
 101 g_mutex_free_posix_impl (GMutex * mutex)
 102 {
 103   posix_check_for_error (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
 104   g_free (mutex);
 105 }
 106
 107 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
 108    functions from gmem.c and gmessages.c; */
 109
 110 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
 111    signature and semantic are right, but without error check then!!!!,
 112    we might want to change this therefore. */
 113
 114 static gboolean
 115 g_mutex_trylock_posix_impl (GMutex * mutex)
 116 {
 117   int result;
 118
 119   result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
 120
 121 #ifdef G_THREADS_IMPL_POSIX
 122   if (result == EBUSY)
 123     return FALSE;
 124 #else /* G_THREADS_IMPL_DCE */
 125   if (result == 0)
 126     return FALSE;
 127 #endif
 128
 129   posix_check_for_error (result);
 130   return TRUE;
 131 }
 132
 133 static GCond *
 134 g_cond_new_posix_impl (void)
 135 {
 136   GCond *result = (GCond *) g_new (pthread_cond_t, 1);
 137   posix_check_for_error (pthread_cond_init ((pthread_cond_t *) result,
 138                                             condattr_default));
 139   return result;
 140 }
 141
 142 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
 143    can be taken directly, as signature and semantic are right, but
 144    without error check then!!!!, we might want to change this
 145    therfore. */
 146
 147 #define G_NSEC_PER_SEC 1000000000
 148
 149 static gboolean
 150 g_cond_timed_wait_posix_impl (GCond * cond,
 151                               GMutex * entered_mutex,
 152                               GTimeVal * abs_time)
 153 {
 154   int result;
 155   struct timespec end_time;
 156   gboolean timed_out;
 157
 158   g_return_val_if_fail (cond != NULL, FALSE);
 159   g_return_val_if_fail (entered_mutex != NULL, FALSE);
 160
 161   if (!abs_time)
 162     {
 163       g_cond_wait (cond, entered_mutex);
 164       return TRUE;
 165     }
 166
 167   end_time.tv_sec = abs_time->tv_sec;
 168   end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 169   g_assert (end_time.tv_nsec < G_NSEC_PER_SEC);
 170   result = pthread_cond_timedwait ((pthread_cond_t *) cond,
 171                                    (pthread_mutex_t *) entered_mutex,
 172                                    &end_time);
 173
 174 #ifdef G_THREADS_IMPL_POSIX
 175   timed_out = (result == ETIMEDOUT);
 176 #else /* G_THREADS_IMPL_DCE */
 177   timed_out = (result == -1) && (errno = EAGAIN);
 178 #endif
 179
 180   if (!timed_out)
 181     posix_check_for_error (result);
 182   return !timed_out;
 183 }
 184
 185 static void
 186 g_cond_free_posix_impl (GCond * cond)
 187 {
 188   posix_check_for_error (pthread_cond_destroy ((pthread_cond_t *) cond));
 189   g_free (cond);
 190 }
 191
 192 static GPrivate *
 193 g_private_new_posix_impl (GDestroyNotify destructor)
 194 {
 195   GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
 196   posix_check_for_error (pthread_key_create ((pthread_key_t *) result,
 197                                              destructor));
 198   return result;
 199 }
 200
 201 /* NOTE: the functions g_private_get and g_private_set may not use
 202    functions from gmem.c and gmessages.c */
 203
 204 static void
 205 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
 206 {
 207   if (!private_key)
 208     return;
 209   pthread_setspecific (*(pthread_key_t *) private_key, value);
 210 }
 211
 212 static gpointer
 213 g_private_get_posix_impl (GPrivate * private_key)
 214 {
 215   if (!private_key)
 216     return NULL;
 217 #ifdef G_THREADS_IMPL_POSIX
 218   return pthread_getspecific (*(pthread_key_t *) private_key);
 219 #else /* G_THREADS_IMPL_DCE */
 220   {
 221     void* data;
 222     posix_check_for_error (pthread_getspecific (*(pthread_key_t *)
 223                                                 private_key, &data));
 224     return data;
 225   }
 226 #endif
 227 }
 228
 229 static void
 230 g_thread_create_posix_impl (GThreadFunc thread_func,
 231                             gpointer arg,
 232                             gulong stack_size,
 233                             gboolean joinable,
 234                             gboolean bound,
 235                             GThreadPriority priority,
 236                             gpointer thread,
 237                             GError **error)
 238 {
 239   pthread_attr_t attr;
 240   gint ret;
 241
 242   g_return_if_fail (thread_func);
 243
 244   posix_check_for_error (pthread_attr_init (&attr));
 245
 246 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 247   if (stack_size)
 248     {
 249       stack_size = MAX (g_thread_min_stack_size, stack_size);
 250       posix_check_for_error (pthread_attr_setstacksize (&attr, stack_size));
 251     }
 252 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 253
 254 #ifdef PTHREAD_SCOPE_SYSTEM
 255   if (bound)
 256     /* No error check here, because some systems can't do it and we
 257      * simply don't want threads to fail because of that. */
 258     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 259 #endif /* PTHREAD_SCOPE_SYSTEM */
 260
 261 #ifdef G_THREADS_IMPL_POSIX
 262   posix_check_for_error (pthread_attr_setdetachstate (&attr,
 263           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 264 #endif /* G_THREADS_IMPL_POSIX */
 265
 266 #ifdef HAVE_PRIORITIES
 267 # ifdef G_THREADS_IMPL_POSIX
 268   {
 269     struct sched_param sched;
 270     posix_check_for_error (pthread_attr_getschedparam (&attr, &sched));
 271     sched.sched_priority = g_thread_map_priority (priority);
 272     posix_check_for_error (pthread_attr_setschedparam (&attr, &sched));
 273   }
 274 # else /* G_THREADS_IMPL_DCE */
 275   posix_check_for_error
 276     (pthread_attr_setprio (&attr, g_thread_map_priority (priority)));
 277 # endif /* G_THREADS_IMPL_DCE */
 278 #endif /* HAVE_PRIORITIES */
 279
 280   ret = pthread_create (thread, &attr, (void* (*)(void*))thread_func, arg);
 281
 282 #ifdef G_THREADS_IMPL_DCE
 283   if (ret == -1)
 284     ret = errno;
 285   else
 286     ret = 0;
 287 #endif /* G_THREADS_IMPL_DCE */
 288
 289   posix_check_for_error (pthread_attr_destroy (&attr));
 290
 291   if (ret == EAGAIN)
 292     {
 293       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 294                    "Error creating thread: %s", g_strerror (ret));
 295       return;
 296     }
 297
 298   posix_check_for_error (ret);
 299
 300 #ifdef G_THREADS_IMPL_DCE
 301   if (!joinable)
 302     posix_check_for_error (pthread_detach (thread));
 303 #endif /* G_THREADS_IMPL_DCE */
 304 }
 305
 306 static void
 307 g_thread_yield_posix_impl (void)
 308 {
 309   POSIX_YIELD_FUNC;
 310 }
 311
 312 static void
 313 g_thread_join_posix_impl (gpointer thread)
 314 {
 315   gpointer ignore;
 316   posix_check_for_error (pthread_join (*(pthread_t*)thread,
 317                                        &ignore));
 318 }
 319
 320 static void
 321 g_thread_exit_posix_impl (void)
 322 {
 323   pthread_exit (NULL);
 324 }
 325
 326 static void
 327 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 328 {
 329 #ifdef HAVE_PRIORITIES
 330 # ifdef G_THREADS_IMPL_POSIX
 331   struct sched_param sched;
 332   int policy;
 333   posix_check_for_error (pthread_getschedparam (*(pthread_t*)thread,
 334                                                 &policy, &sched));
 335   sched.sched_priority = g_thread_map_priority (priority);
 336   posix_check_for_error (pthread_setschedparam (*(pthread_t*)thread,
 337                                                 policy, &sched));
 338 # else /* G_THREADS_IMPL_DCE */
 339   posix_check_for_error (pthread_setprio (*(pthread_t*)thread,
 340                                           g_thread_map_priority (priority)));
 341 # endif
 342 #endif /* HAVE_PRIORITIES */
 343 }
 344
 345 static void
 346 g_thread_self_posix_impl (gpointer thread)
 347 {
 348   *(pthread_t*)thread = pthread_self();
 349 }
 350
 351 static GThreadFunctions g_thread_functions_for_glib_use_default =
 352 {
 353   g_mutex_new_posix_impl,
 354   (void (*)(GMutex *)) pthread_mutex_lock,
 355   g_mutex_trylock_posix_impl,
 356   (void (*)(GMutex *)) pthread_mutex_unlock,
 357   g_mutex_free_posix_impl,
 358   g_cond_new_posix_impl,
 359   (void (*)(GCond *)) pthread_cond_signal,
 360   (void (*)(GCond *)) pthread_cond_broadcast,
 361   (void (*)(GCond *, GMutex *)) pthread_cond_wait,
 362   g_cond_timed_wait_posix_impl,
 363   g_cond_free_posix_impl,
 364   g_private_new_posix_impl,
 365   g_private_get_posix_impl,
 366   g_private_set_posix_impl,
 367   g_thread_create_posix_impl,
 368   g_thread_yield_posix_impl,
 369   g_thread_join_posix_impl,
 370   g_thread_exit_posix_impl,
 371   g_thread_set_priority_posix_impl,
 372   g_thread_self_posix_impl
 373 };