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 static gint priority_normal_value;
 101 # ifdef __FreeBSD__
 102    /* FreeBSD threads use different priority values from the POSIX_
 103     * defines so we just set them here. The corresponding macros
 104     * PTHREAD_MIN_PRIORITY and PTHREAD_MAX_PRIORITY are implied to be
 105     * exported by the docs, but they aren't.
 106     */
 107 #  define PRIORITY_LOW_VALUE      0
 108 #  define PRIORITY_URGENT_VALUE   31
 109 # else /* !__FreeBSD__ */
 110 #  define PRIORITY_LOW_VALUE      POSIX_MIN_PRIORITY
 111 #  define PRIORITY_URGENT_VALUE   POSIX_MAX_PRIORITY
 112 # endif /* !__FreeBSD__ */
 113 # define PRIORITY_NORMAL_VALUE    priority_normal_value
 114 #endif /* POSIX_MIN_PRIORITY && POSIX_MAX_PRIORITY */
 115
 116 static gulong g_thread_min_stack_size = 0;
 117
 118 #define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
 119
 120 #if defined(_SC_THREAD_STACK_MIN) || defined (HAVE_PRIORITIES)
 121 #define HAVE_G_THREAD_IMPL_INIT
 122 static void
 123 g_thread_impl_init()
 124 {
 125 #ifdef _SC_THREAD_STACK_MIN
 126   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
 127 #endif /* _SC_THREAD_STACK_MIN */
 128 #ifdef HAVE_PRIORITIES
 129 # ifdef G_THREADS_IMPL_POSIX
 130   {
 131     struct sched_param sched;
 132     int policy;
 133     posix_check_cmd (pthread_getschedparam (pthread_self(), &policy, &sched));
 134     priority_normal_value = sched.sched_priority;
 135   }
 136 # else /* G_THREADS_IMPL_DCE */
 137   posix_check_cmd (priority_normal_value =
 138                    pthread_getprio (*(pthread_t*)thread,
 139                                     g_thread_priority_map [priority]));
 140 # endif
 141 #endif /* HAVE_PRIORITIES */
 142
 143 }
 144 #endif /* _SC_THREAD_STACK_MIN || HAVE_PRIORITIES */
 145
 146 static GMutex *
 147 g_mutex_new_posix_impl (void)
 148 {
 149   GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
 150   posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
 151                                        mutexattr_default));
 152   return result;
 153 }
 154
 155 static void
 156 g_mutex_free_posix_impl (GMutex * mutex)
 157 {
 158   posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
 159   g_free (mutex);
 160 }
 161
 162 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
 163    functions from gmem.c and gmessages.c; */
 164
 165 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
 166    signature and semantic are right, but without error check then!!!!,
 167    we might want to change this therefore. */
 168
 169 static gboolean
 170 g_mutex_trylock_posix_impl (GMutex * mutex)
 171 {
 172   int result;
 173
 174   result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
 175
 176 #ifdef G_THREADS_IMPL_POSIX
 177   if (result == EBUSY)
 178     return FALSE;
 179 #else /* G_THREADS_IMPL_DCE */
 180   if (result == 0)
 181     return FALSE;
 182 #endif
 183
 184   posix_check_err (posix_error (result), "pthread_mutex_trylock");
 185   return TRUE;
 186 }
 187
 188 static GCond *
 189 g_cond_new_posix_impl (void)
 190 {
 191   GCond *result = (GCond *) g_new (pthread_cond_t, 1);
 192   posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
 193                                       condattr_default));
 194   return result;
 195 }
 196
 197 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
 198    can be taken directly, as signature and semantic are right, but
 199    without error check then!!!!, we might want to change this
 200    therfore. */
 201
 202 #define G_NSEC_PER_SEC 1000000000
 203
 204 static gboolean
 205 g_cond_timed_wait_posix_impl (GCond * cond,
 206                               GMutex * entered_mutex,
 207                               GTimeVal * abs_time)
 208 {
 209   int result;
 210   struct timespec end_time;
 211   gboolean timed_out;
 212
 213   g_return_val_if_fail (cond != NULL, FALSE);
 214   g_return_val_if_fail (entered_mutex != NULL, FALSE);
 215
 216   if (!abs_time)
 217     {
 218       g_cond_wait (cond, entered_mutex);
 219       return TRUE;
 220     }
 221
 222   end_time.tv_sec = abs_time->tv_sec;
 223   end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 224
 225   g_return_val_if_fail (end_time.tv_nsec < G_NSEC_PER_SEC, TRUE);
 226
 227   result = pthread_cond_timedwait ((pthread_cond_t *) cond,
 228                                    (pthread_mutex_t *) entered_mutex,
 229                                    &end_time);
 230
 231 #ifdef G_THREADS_IMPL_POSIX
 232   timed_out = (result == ETIMEDOUT);
 233 #else /* G_THREADS_IMPL_DCE */
 234   timed_out = (result == -1) && (errno == EAGAIN);
 235 #endif
 236
 237   if (!timed_out)
 238     posix_check_err (posix_error (result), "pthread_cond_timedwait");
 239   return !timed_out;
 240 }
 241
 242 static void
 243 g_cond_free_posix_impl (GCond * cond)
 244 {
 245   posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
 246   g_free (cond);
 247 }
 248
 249 static GPrivate *
 250 g_private_new_posix_impl (GDestroyNotify destructor)
 251 {
 252   GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
 253   posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
 254   return result;
 255 }
 256
 257 /* NOTE: the functions g_private_get and g_private_set may not use
 258    functions from gmem.c and gmessages.c */
 259
 260 static void
 261 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
 262 {
 263   if (!private_key)
 264     return;
 265   pthread_setspecific (*(pthread_key_t *) private_key, value);
 266 }
 267
 268 static gpointer
 269 g_private_get_posix_impl (GPrivate * private_key)
 270 {
 271   if (!private_key)
 272     return NULL;
 273 #ifdef G_THREADS_IMPL_POSIX
 274   return pthread_getspecific (*(pthread_key_t *) private_key);
 275 #else /* G_THREADS_IMPL_DCE */
 276   {
 277     void* data;
 278     posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
 279                                           &data));
 280     return data;
 281   }
 282 #endif
 283 }
 284
 285 static void
 286 g_thread_create_posix_impl (GThreadFunc thread_func,
 287                             gpointer arg,
 288                             gulong stack_size,
 289                             gboolean joinable,
 290                             gboolean bound,
 291                             GThreadPriority priority,
 292                             gpointer thread,
 293                             GError **error)
 294 {
 295   pthread_attr_t attr;
 296   gint ret;
 297
 298   g_return_if_fail (thread_func);
 299   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 300   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 301
 302   posix_check_cmd (pthread_attr_init (&attr));
 303
 304 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 305   if (stack_size)
 306     {
 307       stack_size = MAX (g_thread_min_stack_size, stack_size);
 308       posix_check_cmd (pthread_attr_setstacksize (&attr, stack_size));
 309     }
 310 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 311
 312 #ifdef PTHREAD_SCOPE_SYSTEM
 313   if (bound)
 314     /* No error check here, because some systems can't do it and we
 315      * simply don't want threads to fail because of that. */
 316     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 317 #endif /* PTHREAD_SCOPE_SYSTEM */
 318
 319 #ifdef G_THREADS_IMPL_POSIX
 320   posix_check_cmd (pthread_attr_setdetachstate (&attr,
 321           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 322 #endif /* G_THREADS_IMPL_POSIX */
 323
 324 #ifdef HAVE_PRIORITIES
 325 # ifdef G_THREADS_IMPL_POSIX
 326   {
 327     struct sched_param sched;
 328     posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
 329     sched.sched_priority = g_thread_priority_map [priority];
 330     posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
 331   }
 332 # else /* G_THREADS_IMPL_DCE */
 333   posix_check_cmd_prio
 334     (pthread_attr_setprio (&attr, g_thread_priority_map [priority]));
 335 # endif /* G_THREADS_IMPL_DCE */
 336 #endif /* HAVE_PRIORITIES */
 337   ret = posix_error (pthread_create (thread, &attr,
 338                                      (void* (*)(void*))thread_func, arg));
 339
 340   posix_check_cmd (pthread_attr_destroy (&attr));
 341
 342   if (ret == EAGAIN)
 343     {
 344       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 345                    "Error creating thread: %s", g_strerror (ret));
 346       return;
 347     }
 348
 349   posix_check_err (ret, "pthread_create");
 350
 351 #ifdef G_THREADS_IMPL_DCE
 352   if (!joinable)
 353     posix_check_cmd (pthread_detach (thread));
 354 #endif /* G_THREADS_IMPL_DCE */
 355 }
 356
 357 static void
 358 g_thread_yield_posix_impl (void)
 359 {
 360   POSIX_YIELD_FUNC;
 361 }
 362
 363 static void
 364 g_thread_join_posix_impl (gpointer thread)
 365 {
 366   gpointer ignore;
 367   posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
 368 }
 369
 370 static void
 371 g_thread_exit_posix_impl (void)
 372 {
 373   pthread_exit (NULL);
 374 }
 375
 376 static void
 377 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 378 {
 379   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 380   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 381 #ifdef HAVE_PRIORITIES
 382 # ifdef G_THREADS_IMPL_POSIX
 383   {
 384     struct sched_param sched;
 385     int policy;
 386     posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
 387                                             &sched));
 388     sched.sched_priority = g_thread_priority_map [priority];
 389     posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
 390                                                  &sched));
 391   }
 392 # else /* G_THREADS_IMPL_DCE */
 393   posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
 394                                          g_thread_priority_map [priority]));
 395 # endif
 396 #endif /* HAVE_PRIORITIES */
 397 }
 398
 399 static void
 400 g_thread_self_posix_impl (gpointer thread)
 401 {
 402   *(pthread_t*)thread = pthread_self();
 403 }
 404
 405 static gboolean
 406 g_thread_equal_posix_impl (gpointer thread1, gpointer thread2)
 407 {
 408   return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
 409 }
 410
 411 static GThreadFunctions g_thread_functions_for_glib_use_default =
 412 {
 413   g_mutex_new_posix_impl,
 414   (void (*)(GMutex *)) pthread_mutex_lock,
 415   g_mutex_trylock_posix_impl,
 416   (void (*)(GMutex *)) pthread_mutex_unlock,
 417   g_mutex_free_posix_impl,
 418   g_cond_new_posix_impl,
 419   (void (*)(GCond *)) pthread_cond_signal,
 420   (void (*)(GCond *)) pthread_cond_broadcast,
 421   (void (*)(GCond *, GMutex *)) pthread_cond_wait,
 422   g_cond_timed_wait_posix_impl,
 423   g_cond_free_posix_impl,
 424   g_private_new_posix_impl,
 425   g_private_get_posix_impl,
 426   g_private_set_posix_impl,
 427   g_thread_create_posix_impl,
 428   g_thread_yield_posix_impl,
 429   g_thread_join_posix_impl,
 430   g_thread_exit_posix_impl,
 431   g_thread_set_priority_posix_impl,
 432   g_thread_self_posix_impl,
 433   g_thread_equal_posix_impl
 434 };