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 <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_GNUC_PRETTY_FUNCTION,                  \
  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(_SC_THREAD_STACK_MIN) || defined (HAVE_PRIORITIES)
 123 #define HAVE_G_THREAD_IMPL_INIT
 124 static void
 125 g_thread_impl_init(void)
 126 {
 127 #ifdef _SC_THREAD_STACK_MIN
 128   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
 129 #endif /* _SC_THREAD_STACK_MIN */
 130 #ifdef HAVE_PRIORITIES
 131 # ifdef G_THREADS_IMPL_POSIX
 132   {
 133     struct sched_param sched;
 134     int policy;
 135     posix_check_cmd (pthread_getschedparam (pthread_self(), &policy, &sched));
 136     priority_normal_value = sched.sched_priority;
 137   }
 138 # else /* G_THREADS_IMPL_DCE */
 139   posix_check_cmd (priority_normal_value =
 140                    pthread_getprio (*(pthread_t*)thread,
 141                                     g_thread_priority_map [priority]));
 142 # endif
 143 #endif /* HAVE_PRIORITIES */
 144
 145 }
 146 #endif /* _SC_THREAD_STACK_MIN || HAVE_PRIORITIES */
 147
 148 static GMutex *
 149 g_mutex_new_posix_impl (void)
 150 {
 151   GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
 152   posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
 153                                        mutexattr_default));
 154   return result;
 155 }
 156
 157 static void
 158 g_mutex_free_posix_impl (GMutex * mutex)
 159 {
 160   posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
 161   g_free (mutex);
 162 }
 163
 164 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
 165    functions from gmem.c and gmessages.c; */
 166
 167 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
 168    signature and semantic are right, but without error check then!!!!,
 169    we might want to change this therefore. */
 170
 171 static gboolean
 172 g_mutex_trylock_posix_impl (GMutex * mutex)
 173 {
 174   int result;
 175
 176   result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
 177
 178 #ifdef G_THREADS_IMPL_POSIX
 179   if (result == EBUSY)
 180     return FALSE;
 181 #else /* G_THREADS_IMPL_DCE */
 182   if (result == 0)
 183     return FALSE;
 184 #endif
 185
 186   posix_check_err (posix_error (result), "pthread_mutex_trylock");
 187   return TRUE;
 188 }
 189
 190 static GCond *
 191 g_cond_new_posix_impl (void)
 192 {
 193   GCond *result = (GCond *) g_new (pthread_cond_t, 1);
 194   posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
 195                                       condattr_default));
 196   return result;
 197 }
 198
 199 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
 200    can be taken directly, as signature and semantic are right, but
 201    without error check then!!!!, we might want to change this
 202    therfore. */
 203
 204 #define G_NSEC_PER_SEC 1000000000
 205
 206 static gboolean
 207 g_cond_timed_wait_posix_impl (GCond * cond,
 208                               GMutex * entered_mutex,
 209                               GTimeVal * abs_time)
 210 {
 211   int result;
 212   struct timespec end_time;
 213   gboolean timed_out;
 214
 215   g_return_val_if_fail (cond != NULL, FALSE);
 216   g_return_val_if_fail (entered_mutex != NULL, FALSE);
 217
 218   if (!abs_time)
 219     {
 220       g_cond_wait (cond, entered_mutex);
 221       return TRUE;
 222     }
 223
 224   end_time.tv_sec = abs_time->tv_sec;
 225   end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 226
 227   g_return_val_if_fail (end_time.tv_nsec < G_NSEC_PER_SEC, TRUE);
 228
 229   result = pthread_cond_timedwait ((pthread_cond_t *) cond,
 230                                    (pthread_mutex_t *) entered_mutex,
 231                                    &end_time);
 232
 233 #ifdef G_THREADS_IMPL_POSIX
 234   timed_out = (result == ETIMEDOUT);
 235 #else /* G_THREADS_IMPL_DCE */
 236   timed_out = (result == -1) && (errno == EAGAIN);
 237 #endif
 238
 239   if (!timed_out)
 240     posix_check_err (posix_error (result), "pthread_cond_timedwait");
 241   return !timed_out;
 242 }
 243
 244 static void
 245 g_cond_free_posix_impl (GCond * cond)
 246 {
 247   posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
 248   g_free (cond);
 249 }
 250
 251 static GPrivate *
 252 g_private_new_posix_impl (GDestroyNotify destructor)
 253 {
 254   GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
 255   posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
 256   return result;
 257 }
 258
 259 /* NOTE: the functions g_private_get and g_private_set may not use
 260    functions from gmem.c and gmessages.c */
 261
 262 static void
 263 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
 264 {
 265   if (!private_key)
 266     return;
 267   pthread_setspecific (*(pthread_key_t *) private_key, value);
 268 }
 269
 270 static gpointer
 271 g_private_get_posix_impl (GPrivate * private_key)
 272 {
 273   if (!private_key)
 274     return NULL;
 275 #ifdef G_THREADS_IMPL_POSIX
 276   return pthread_getspecific (*(pthread_key_t *) private_key);
 277 #else /* G_THREADS_IMPL_DCE */
 278   {
 279     void* data;
 280     posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
 281                                           &data));
 282     return data;
 283   }
 284 #endif
 285 }
 286
 287 static void
 288 g_thread_create_posix_impl (GThreadFunc thread_func,
 289                             gpointer arg,
 290                             gulong stack_size,
 291                             gboolean joinable,
 292                             gboolean bound,
 293                             GThreadPriority priority,
 294                             gpointer thread,
 295                             GError **error)
 296 {
 297   pthread_attr_t attr;
 298   gint ret;
 299
 300   g_return_if_fail (thread_func);
 301   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 302   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 303
 304   posix_check_cmd (pthread_attr_init (&attr));
 305
 306 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 307   if (stack_size)
 308     {
 309       stack_size = MAX (g_thread_min_stack_size, stack_size);
 310       /* No error check here, because some systems can't do it and
 311        * we simply don't want threads to fail because of that. */
 312       pthread_attr_setstacksize (&attr, stack_size);
 313     }
 314 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 315
 316 #ifdef PTHREAD_SCOPE_SYSTEM
 317   if (bound)
 318     /* No error check here, because some systems can't do it and we
 319      * simply don't want threads to fail because of that. */
 320     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 321 #endif /* PTHREAD_SCOPE_SYSTEM */
 322
 323 #ifdef G_THREADS_IMPL_POSIX
 324   posix_check_cmd (pthread_attr_setdetachstate (&attr,
 325           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 326 #endif /* G_THREADS_IMPL_POSIX */
 327
 328 #ifdef HAVE_PRIORITIES
 329 # ifdef G_THREADS_IMPL_POSIX
 330   {
 331     struct sched_param sched;
 332     posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
 333     sched.sched_priority = g_thread_priority_map [priority];
 334     posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
 335   }
 336 # else /* G_THREADS_IMPL_DCE */
 337   posix_check_cmd_prio
 338     (pthread_attr_setprio (&attr, g_thread_priority_map [priority]));
 339 # endif /* G_THREADS_IMPL_DCE */
 340 #endif /* HAVE_PRIORITIES */
 341   ret = posix_error (pthread_create (thread, &attr,
 342                                      (void* (*)(void*))thread_func, arg));
 343
 344   posix_check_cmd (pthread_attr_destroy (&attr));
 345
 346   if (ret == EAGAIN)
 347     {
 348       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 349                    "Error creating thread: %s", g_strerror (ret));
 350       return;
 351     }
 352
 353   posix_check_err (ret, "pthread_create");
 354
 355 #ifdef G_THREADS_IMPL_DCE
 356   if (!joinable)
 357     posix_check_cmd (pthread_detach (thread));
 358 #endif /* G_THREADS_IMPL_DCE */
 359 }
 360
 361 static void
 362 g_thread_yield_posix_impl (void)
 363 {
 364   POSIX_YIELD_FUNC;
 365 }
 366
 367 static void
 368 g_thread_join_posix_impl (gpointer thread)
 369 {
 370   gpointer ignore;
 371   posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
 372 }
 373
 374 static void
 375 g_thread_exit_posix_impl (void)
 376 {
 377   pthread_exit (NULL);
 378 }
 379
 380 static void
 381 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 382 {
 383   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 384   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 385 #ifdef HAVE_PRIORITIES
 386 # ifdef G_THREADS_IMPL_POSIX
 387   {
 388     struct sched_param sched;
 389     int policy;
 390     posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
 391                                             &sched));
 392     sched.sched_priority = g_thread_priority_map [priority];
 393     posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
 394                                                  &sched));
 395   }
 396 # else /* G_THREADS_IMPL_DCE */
 397   posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
 398                                          g_thread_priority_map [priority]));
 399 # endif
 400 #endif /* HAVE_PRIORITIES */
 401 }
 402
 403 static void
 404 g_thread_self_posix_impl (gpointer thread)
 405 {
 406   *(pthread_t*)thread = pthread_self();
 407 }
 408
 409 static gboolean
 410 g_thread_equal_posix_impl (gpointer thread1, gpointer thread2)
 411 {
 412   return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
 413 }
 414
 415 static GThreadFunctions g_thread_functions_for_glib_use_default =
 416 {
 417   g_mutex_new_posix_impl,
 418   (void (*)(GMutex *)) pthread_mutex_lock,
 419   g_mutex_trylock_posix_impl,
 420   (void (*)(GMutex *)) pthread_mutex_unlock,
 421   g_mutex_free_posix_impl,
 422   g_cond_new_posix_impl,
 423   (void (*)(GCond *)) pthread_cond_signal,
 424   (void (*)(GCond *)) pthread_cond_broadcast,
 425   (void (*)(GCond *, GMutex *)) pthread_cond_wait,
 426   g_cond_timed_wait_posix_impl,
 427   g_cond_free_posix_impl,
 428   g_private_new_posix_impl,
 429   g_private_get_posix_impl,
 430   g_private_set_posix_impl,
 431   g_thread_create_posix_impl,
 432   g_thread_yield_posix_impl,
 433   g_thread_join_posix_impl,
 434   g_thread_exit_posix_impl,
 435   g_thread_set_priority_posix_impl,
 436   g_thread_self_posix_impl,
 437   g_thread_equal_posix_impl
 438 };