glib/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 /* The GMutex, GCond and GPrivate implementations in this file are some
  31  * of the lowest-level code in GLib.  All other parts of GLib (messages,
  32  * memory, slices, etc) assume that they can freely use these facilities
  33  * without risking recursion.
  34  *
  35  * As such, these functions are NOT permitted to call any other part of
  36  * GLib.
  37  *
  38  * The thread manipulation functions (create, exit, join, etc.) have
  39  * more freedom -- they can do as they please.
  40  */
  41
  42 #include "config.h"
  43
  44 #include "gthread.h"
  45 #include "gthreadprivate.h"
  46
  47 #include <pthread.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <errno.h>
  51 #include <stdio.h>
  52
  53 static void
  54 g_thread_abort (gint         status,
  55                 const gchar *function)
  56 {
  57   fprintf (stderr, "GLib (gthread-posix.c): Unexpected error from C library during '%s': %s.  Aborting.\n",
  58            strerror (status), function);
  59   abort ();
  60 }
  61
  62 /* {{{1 GMutex */
  63 void
  64 g_mutex_init (GMutex *mutex)
  65 {
  66   gint status;
  67
  68   if G_UNLIKELY ((status = pthread_mutex_init (&mutex->impl, NULL)) != 0)
  69     g_thread_abort (status, "pthread_mutex_init");
  70 }
  71
  72 void
  73 g_mutex_clear (GMutex *mutex)
  74 {
  75   gint status;
  76
  77   if G_UNLIKELY ((status = pthread_mutex_destroy (&mutex->impl)) != 0)
  78     g_thread_abort (status, "pthread_mutex_destroy");
  79 }
  80
  81 void
  82 g_mutex_lock (GMutex *mutex)
  83 {
  84   gint status;
  85
  86   if G_UNLIKELY ((status = pthread_mutex_lock (&mutex->impl)) != 0)
  87     g_thread_abort (status, "pthread_mutex_lock");
  88 }
  89
  90 void
  91 g_mutex_unlock (GMutex *mutex)
  92 {
  93   gint status;
  94
  95   if G_UNLIKELY ((status = pthread_mutex_unlock (&mutex->impl)) != 0)
  96     g_thread_abort (status, "pthread_mutex_lock");
  97 }
  98
  99 gboolean
 100 g_mutex_trylock (GMutex *mutex)
 101 {
 102   gint status;
 103
 104   if G_LIKELY ((status = pthread_mutex_trylock (&mutex->impl)) == 0)
 105     return TRUE;
 106
 107   if G_UNLIKELY (status != EBUSY)
 108     g_thread_abort (status, "pthread_mutex_trylock");
 109
 110   return FALSE;
 111 }
 112
 113 /* {{{1 GCond */
 114
 115 void
 116 g_cond_init (GCond *cond)
 117 {
 118   gint status;
 119
 120   if G_UNLIKELY ((status = pthread_cond_init (&cond->impl, NULL)) != 0)
 121     g_thread_abort (status, "pthread_cond_init");
 122 }
 123
 124 void
 125 g_cond_clear (GCond *cond)
 126 {
 127   gint status;
 128
 129   if G_UNLIKELY ((status = pthread_cond_destroy (&cond->impl)) != 0)
 130     g_thread_abort (status, "pthread_cond_destroy");
 131 }
 132
 133 void
 134 g_cond_wait (GCond  *cond,
 135              GMutex *mutex)
 136 {
 137   gint status;
 138
 139   if G_UNLIKELY ((status = pthread_cond_wait (&cond->impl, &mutex->impl)) != 0)
 140     g_thread_abort (status, "pthread_cond_wait");
 141 }
 142
 143 void
 144 g_cond_signal (GCond *cond)
 145 {
 146   gint status;
 147
 148   if G_UNLIKELY ((status = pthread_cond_signal (&cond->impl)) != 0)
 149     g_thread_abort (status, "pthread_cond_signal");
 150 }
 151
 152 void
 153 g_cond_broadcast (GCond *cond)
 154 {
 155   gint status;
 156
 157   if G_UNLIKELY ((status = pthread_cond_broadcast (&cond->impl)) != 0)
 158     g_thread_abort (status, "pthread_cond_broadcast");
 159 }
 160
 161 gboolean
 162 g_cond_timed_wait (GCond    *cond,
 163                    GMutex   *mutex,
 164                    GTimeVal *abs_time)
 165 {
 166   struct timespec end_time;
 167   gint status;
 168
 169   if (abs_time == NULL)
 170     {
 171       g_cond_wait (cond, mutex);
 172       return TRUE;
 173     }
 174
 175   end_time.tv_sec = abs_time->tv_sec;
 176   end_time.tv_nsec = abs_time->tv_usec * 1000;
 177
 178   if ((status = pthread_cond_timedwait (&cond->impl, &mutex->impl, &end_time)) == 0)
 179     return TRUE;
 180
 181   if G_UNLIKELY (status != ETIMEDOUT)
 182     g_thread_abort (status, "pthread_cond_timedwait");
 183
 184   return FALSE;
 185 }
 186
 187 gboolean
 188 g_cond_timedwait (GCond  *cond,
 189                   GMutex *mutex,
 190                   gint64  abs_time)
 191 {
 192   struct timespec end_time;
 193   gint status;
 194
 195   end_time.tv_sec = abs_time / 1000000;
 196   end_time.tv_nsec = (abs_time % 1000000) * 1000;
 197
 198   if ((status = pthread_cond_timedwait (&cond->impl, &mutex->impl, &end_time)) == 0)
 199     return TRUE;
 200
 201   if G_UNLIKELY (status != ETIMEDOUT)
 202     g_thread_abort (status, "pthread_cond_timedwait");
 203
 204   return FALSE;
 205 }
 206
 207 /* {{{1 GPrivate */
 208
 209 GPrivate *
 210 g_private_new (GDestroyNotify notify)
 211 {
 212   GPrivate *key;
 213
 214   key = malloc (sizeof (GPrivate));
 215   if G_UNLIKELY (key == NULL)
 216     g_thread_abort (errno, "malloc");
 217   g_private_init (key, notify);
 218
 219   return key;
 220 }
 221
 222 void
 223 g_private_init (GPrivate       *key,
 224                 GDestroyNotify  notify)
 225 {
 226   pthread_key_create (&key->key, notify);
 227   key->ready = TRUE;
 228 }
 229
 230 gpointer
 231 g_private_get (GPrivate *key)
 232 {
 233   if (!key->ready)
 234     return key->single_value;
 235
 236   /* quote POSIX: No errors are returned from pthread_getspecific(). */
 237   return pthread_getspecific (key->key);
 238 }
 239
 240 void
 241 g_private_set (GPrivate *key,
 242                gpointer  value)
 243 {
 244   gint status;
 245
 246   if (!key->ready)
 247     {
 248       key->single_value = value;
 249       return;
 250     }
 251
 252   if G_UNLIKELY ((status = pthread_setspecific (key->key, value)) != 0)
 253     g_thread_abort (status, "pthread_setspecific");
 254 }
 255
 256 /* {{{1 GThread */
 257
 258 #include "glib.h"
 259 #include "gthreadprivate.h"
 260
 261 #include <pthread.h>
 262 #include <errno.h>
 263 #include <stdlib.h>
 264 #ifdef HAVE_SYS_TIME_H
 265 # include <sys/time.h>
 266 #endif
 267 #ifdef HAVE_UNISTD_H
 268 # include <unistd.h>
 269 #endif
 270
 271 #ifdef HAVE_SCHED_H
 272 #include <sched.h>
 273 #endif
 274
 275 #define posix_check_err(err, name) G_STMT_START{                        \
 276   int error = (err);                                                    \
 277   if (error)                                                            \
 278     g_error ("file %s: line %d (%s): error '%s' during '%s'",           \
 279            __FILE__, __LINE__, G_STRFUNC,                               \
 280            g_strerror (error), name);                                   \
 281   }G_STMT_END
 282
 283 #define posix_check_cmd(cmd) posix_check_err (cmd, #cmd)
 284
 285 #ifdef G_ENABLE_DEBUG
 286 static gboolean posix_check_cmd_prio_warned = FALSE;
 287 # define posix_check_cmd_prio(cmd) G_STMT_START{                        \
 288     int err = (cmd);                                                    \
 289     if (err == EPERM)                                                   \
 290       {                                                                 \
 291         if (!posix_check_cmd_prio_warned)                               \
 292           {                                                             \
 293             posix_check_cmd_prio_warned = TRUE;                         \
 294             g_warning ("Priorities can only be changed "                \
 295                         "(resp. increased) by root.");                  \
 296           }                                                             \
 297       }                                                                 \
 298     else                                                                \
 299       posix_check_err (err, #cmd);                                      \
 300      }G_STMT_END
 301 #else /* G_ENABLE_DEBUG */
 302 # define posix_check_cmd_prio(cmd) G_STMT_START{                        \
 303     int err = (cmd);                                                    \
 304     if (err != EPERM)                                                   \
 305       posix_check_err (err, #cmd);                                      \
 306      }G_STMT_END
 307 #endif /* G_ENABLE_DEBUG */
 308
 309 #if defined (POSIX_MIN_PRIORITY) && defined (POSIX_MAX_PRIORITY)
 310 # define HAVE_PRIORITIES 1
 311 static gint priority_normal_value;
 312 # ifdef __FreeBSD__
 313    /* FreeBSD threads use different priority values from the POSIX_
 314     * defines so we just set them here. The corresponding macros
 315     * PTHREAD_MIN_PRIORITY and PTHREAD_MAX_PRIORITY are implied to be
 316     * exported by the docs, but they aren't.
 317     */
 318 #  define PRIORITY_LOW_VALUE      0
 319 #  define PRIORITY_URGENT_VALUE   31
 320 # else /* !__FreeBSD__ */
 321 #  define PRIORITY_LOW_VALUE      POSIX_MIN_PRIORITY
 322 #  define PRIORITY_URGENT_VALUE   POSIX_MAX_PRIORITY
 323 # endif /* !__FreeBSD__ */
 324 # define PRIORITY_NORMAL_VALUE    priority_normal_value
 325
 326 # define PRIORITY_HIGH_VALUE \
 327     ((PRIORITY_NORMAL_VALUE + PRIORITY_URGENT_VALUE * 2) / 3)
 328
 329 static gint
 330 g_thread_priority_map (GThreadPriority priority)
 331 {
 332   switch (priority)
 333     {
 334     case G_THREAD_PRIORITY_LOW:
 335       return PRIORITY_LOW_VALUE;
 336
 337     case G_THREAD_PRIORITY_NORMAL:
 338       return PRIORITY_NORMAL_VALUE;
 339
 340     case G_THREAD_PRIORITY_HIGH:
 341       return PRIORITY_HIGH_VALUE;
 342
 343     case G_THREAD_PRIORITY_URGENT:
 344       return PRIORITY_URGENT_VALUE;
 345
 346     default:
 347       g_assert_not_reached ();
 348     }
 349 }
 350
 351 #endif /* POSIX_MIN_PRIORITY && POSIX_MAX_PRIORITY */
 352
 353 static gulong g_thread_min_stack_size = 0;
 354
 355 #define G_MUTEX_SIZE (sizeof (pthread_mutex_t))
 356
 357 void
 358 _g_thread_impl_init(void)
 359 {
 360 #ifdef _SC_THREAD_STACK_MIN
 361   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
 362 #endif /* _SC_THREAD_STACK_MIN */
 363 #ifdef HAVE_PRIORITIES
 364   {
 365     struct sched_param sched;
 366     int policy;
 367     posix_check_cmd (pthread_getschedparam (pthread_self(), &policy, &sched));
 368     priority_normal_value = sched.sched_priority;
 369   }
 370 #endif /* HAVE_PRIORITIES */
 371 }
 372
 373 static void
 374 g_thread_create_posix_impl (GThreadFunc thread_func,
 375                             gpointer arg,
 376                             gulong stack_size,
 377                             gboolean joinable,
 378                             gboolean bound,
 379                             GThreadPriority priority,
 380                             gpointer thread,
 381                             GError **error)
 382 {
 383   pthread_attr_t attr;
 384   gint ret;
 385
 386   g_return_if_fail (thread_func);
 387   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 388   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 389
 390   posix_check_cmd (pthread_attr_init (&attr));
 391
 392 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 393   if (stack_size)
 394     {
 395       stack_size = MAX (g_thread_min_stack_size, stack_size);
 396       /* No error check here, because some systems can't do it and
 397        * we simply don't want threads to fail because of that. */
 398       pthread_attr_setstacksize (&attr, stack_size);
 399     }
 400 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 401
 402 #ifdef PTHREAD_SCOPE_SYSTEM
 403   if (bound)
 404     /* No error check here, because some systems can't do it and we
 405      * simply don't want threads to fail because of that. */
 406     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 407 #endif /* PTHREAD_SCOPE_SYSTEM */
 408
 409   posix_check_cmd (pthread_attr_setdetachstate (&attr,
 410           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 411
 412 #ifdef HAVE_PRIORITIES
 413   {
 414     struct sched_param sched;
 415     posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
 416     sched.sched_priority = g_thread_priority_map (priority);
 417     posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
 418   }
 419 #endif /* HAVE_PRIORITIES */
 420   ret = pthread_create (thread, &attr, (void* (*)(void*))thread_func, arg);
 421
 422   posix_check_cmd (pthread_attr_destroy (&attr));
 423
 424   if (ret == EAGAIN)
 425     {
 426       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 427                    "Error creating thread: %s", g_strerror (ret));
 428       return;
 429     }
 430
 431   posix_check_err (ret, "pthread_create");
 432 }
 433
 434 static void
 435 g_thread_yield_posix_impl (void)
 436 {
 437   sched_yield ();
 438 }
 439
 440 static void
 441 g_thread_join_posix_impl (gpointer thread)
 442 {
 443   gpointer ignore;
 444   posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
 445 }
 446
 447 static void
 448 g_thread_exit_posix_impl (void)
 449 {
 450   pthread_exit (NULL);
 451 }
 452
 453 static void
 454 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 455 {
 456   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 457   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 458 #ifdef HAVE_PRIORITIES
 459   {
 460     struct sched_param sched;
 461     int policy;
 462     posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
 463                                             &sched));
 464     sched.sched_priority = g_thread_priority_map (priority);
 465     posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
 466                                                  &sched));
 467   }
 468 #endif /* HAVE_PRIORITIES */
 469 }
 470
 471 static void
 472 g_thread_self_posix_impl (gpointer thread)
 473 {
 474   *(pthread_t*)thread = pthread_self();
 475 }
 476
 477 static gboolean
 478 g_thread_equal_posix_impl (gpointer thread1, gpointer thread2)
 479 {
 480   return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
 481 }
 482
 483 /* {{{1 Epilogue */
 484 GThreadFunctions g_thread_functions_for_glib_use =
 485 {
 486   g_mutex_new,
 487   g_mutex_lock,
 488   g_mutex_trylock,
 489   g_mutex_unlock,
 490   g_mutex_free,
 491   g_cond_new,
 492   g_cond_signal,
 493   g_cond_broadcast,
 494   g_cond_wait,
 495   g_cond_timed_wait,
 496   g_cond_free,
 497   g_private_new,
 498   g_private_get,
 499   g_private_set,
 500   g_thread_create_posix_impl,
 501   g_thread_yield_posix_impl,
 502   g_thread_join_posix_impl,
 503   g_thread_exit_posix_impl,
 504   g_thread_set_priority_posix_impl,
 505   g_thread_self_posix_impl,
 506   g_thread_equal_posix_impl
 507 };
 508
 509 /* vim:set foldmethod=marker: */