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