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(HAVE_CLOCK_GETTIME) && defined(HAVE_MONOTONIC_CLOCK)
 123 #define USE_CLOCK_GETTIME 1
 124 static gint posix_clock = 0;
 125 #endif
 126
 127 #if defined(_SC_THREAD_STACK_MIN) || defined (HAVE_PRIORITIES) || defined (USE_CLOCK_GETTIME)
 128 #define HAVE_G_THREAD_IMPL_INIT
 129 static void
 130 g_thread_impl_init(void)
 131 {
 132 #ifdef _SC_THREAD_STACK_MIN
 133   g_thread_min_stack_size = MAX (sysconf (_SC_THREAD_STACK_MIN), 0);
 134 #endif /* _SC_THREAD_STACK_MIN */
 135 #ifdef HAVE_PRIORITIES
 136 # ifdef G_THREADS_IMPL_POSIX
 137   {
 138     struct sched_param sched;
 139     int policy;
 140     posix_check_cmd (pthread_getschedparam (pthread_self(), &policy, &sched));
 141     priority_normal_value = sched.sched_priority;
 142   }
 143 # else /* G_THREADS_IMPL_DCE */
 144   posix_check_cmd (priority_normal_value =
 145                    pthread_getprio (*(pthread_t*)thread,
 146                                     g_thread_priority_map [priority]));
 147 # endif
 148 #endif /* HAVE_PRIORITIES */
 149
 150 #ifdef USE_CLOCK_GETTIME
 151  if (sysconf (_SC_MONOTONIC_CLOCK) >= 0)
 152    posix_clock = CLOCK_MONOTONIC;
 153  else
 154    posix_clock = CLOCK_REALTIME;
 155 #endif
 156 }
 157 #endif /* _SC_THREAD_STACK_MIN || HAVE_PRIORITIES */
 158
 159 static GMutex *
 160 g_mutex_new_posix_impl (void)
 161 {
 162   GMutex *result = (GMutex *) g_new (pthread_mutex_t, 1);
 163   posix_check_cmd (pthread_mutex_init ((pthread_mutex_t *) result,
 164                                        mutexattr_default));
 165   return result;
 166 }
 167
 168 static void
 169 g_mutex_free_posix_impl (GMutex * mutex)
 170 {
 171   posix_check_cmd (pthread_mutex_destroy ((pthread_mutex_t *) mutex));
 172   g_free (mutex);
 173 }
 174
 175 /* NOTE: the functions g_mutex_lock and g_mutex_unlock may not use
 176    functions from gmem.c and gmessages.c; */
 177
 178 /* pthread_mutex_lock, pthread_mutex_unlock can be taken directly, as
 179    signature and semantic are right, but without error check then!!!!,
 180    we might want to change this therefore. */
 181
 182 static gboolean
 183 g_mutex_trylock_posix_impl (GMutex * mutex)
 184 {
 185   int result;
 186
 187   result = pthread_mutex_trylock ((pthread_mutex_t *) mutex);
 188
 189 #ifdef G_THREADS_IMPL_POSIX
 190   if (result == EBUSY)
 191     return FALSE;
 192 #else /* G_THREADS_IMPL_DCE */
 193   if (result == 0)
 194     return FALSE;
 195 #endif
 196
 197   posix_check_err (posix_error (result), "pthread_mutex_trylock");
 198   return TRUE;
 199 }
 200
 201 static GCond *
 202 g_cond_new_posix_impl (void)
 203 {
 204   GCond *result = (GCond *) g_new (pthread_cond_t, 1);
 205   posix_check_cmd (pthread_cond_init ((pthread_cond_t *) result,
 206                                       condattr_default));
 207   return result;
 208 }
 209
 210 /* pthread_cond_signal, pthread_cond_broadcast and pthread_cond_wait
 211    can be taken directly, as signature and semantic are right, but
 212    without error check then!!!!, we might want to change this
 213    therefore. */
 214
 215 #define G_NSEC_PER_SEC 1000000000
 216
 217 static gboolean
 218 g_cond_timed_wait_posix_impl (GCond * cond,
 219                               GMutex * entered_mutex,
 220                               GTimeVal * abs_time)
 221 {
 222   int result;
 223   struct timespec end_time;
 224   gboolean timed_out;
 225
 226   g_return_val_if_fail (cond != NULL, FALSE);
 227   g_return_val_if_fail (entered_mutex != NULL, FALSE);
 228
 229   if (!abs_time)
 230     {
 231       result = pthread_cond_wait ((pthread_cond_t *)cond,
 232                                   (pthread_mutex_t *) entered_mutex);
 233       timed_out = FALSE;
 234     }
 235   else
 236     {
 237       end_time.tv_sec = abs_time->tv_sec;
 238       end_time.tv_nsec = abs_time->tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 239
 240       g_return_val_if_fail (end_time.tv_nsec < G_NSEC_PER_SEC, TRUE);
 241
 242       result = pthread_cond_timedwait ((pthread_cond_t *) cond,
 243                                        (pthread_mutex_t *) entered_mutex,
 244                                        &end_time);
 245 #ifdef G_THREADS_IMPL_POSIX
 246       timed_out = (result == ETIMEDOUT);
 247 #else /* G_THREADS_IMPL_DCE */
 248       timed_out = (result == -1) && (errno == EAGAIN);
 249 #endif
 250     }
 251
 252   if (!timed_out)
 253     posix_check_err (posix_error (result), "pthread_cond_timedwait");
 254
 255   return !timed_out;
 256 }
 257
 258 static void
 259 g_cond_free_posix_impl (GCond * cond)
 260 {
 261   posix_check_cmd (pthread_cond_destroy ((pthread_cond_t *) cond));
 262   g_free (cond);
 263 }
 264
 265 static GPrivate *
 266 g_private_new_posix_impl (GDestroyNotify destructor)
 267 {
 268   GPrivate *result = (GPrivate *) g_new (pthread_key_t, 1);
 269   posix_check_cmd (pthread_key_create ((pthread_key_t *) result, destructor));
 270   return result;
 271 }
 272
 273 /* NOTE: the functions g_private_get and g_private_set may not use
 274    functions from gmem.c and gmessages.c */
 275
 276 static void
 277 g_private_set_posix_impl (GPrivate * private_key, gpointer value)
 278 {
 279   if (!private_key)
 280     return;
 281   pthread_setspecific (*(pthread_key_t *) private_key, value);
 282 }
 283
 284 static gpointer
 285 g_private_get_posix_impl (GPrivate * private_key)
 286 {
 287   if (!private_key)
 288     return NULL;
 289 #ifdef G_THREADS_IMPL_POSIX
 290   return pthread_getspecific (*(pthread_key_t *) private_key);
 291 #else /* G_THREADS_IMPL_DCE */
 292   {
 293     void* data;
 294     posix_check_cmd (pthread_getspecific (*(pthread_key_t *) private_key,
 295                                           &data));
 296     return data;
 297   }
 298 #endif
 299 }
 300
 301 static void
 302 g_thread_create_posix_impl (GThreadFunc thread_func,
 303                             gpointer arg,
 304                             gulong stack_size,
 305                             gboolean joinable,
 306                             gboolean bound,
 307                             GThreadPriority priority,
 308                             gpointer thread,
 309                             GError **error)
 310 {
 311   pthread_attr_t attr;
 312   gint ret;
 313
 314   g_return_if_fail (thread_func);
 315   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 316   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 317
 318   posix_check_cmd (pthread_attr_init (&attr));
 319
 320 #ifdef HAVE_PTHREAD_ATTR_SETSTACKSIZE
 321   if (stack_size)
 322     {
 323       stack_size = MAX (g_thread_min_stack_size, stack_size);
 324       /* No error check here, because some systems can't do it and
 325        * we simply don't want threads to fail because of that. */
 326       pthread_attr_setstacksize (&attr, stack_size);
 327     }
 328 #endif /* HAVE_PTHREAD_ATTR_SETSTACKSIZE */
 329
 330 #ifdef PTHREAD_SCOPE_SYSTEM
 331   if (bound)
 332     /* No error check here, because some systems can't do it and we
 333      * simply don't want threads to fail because of that. */
 334     pthread_attr_setscope (&attr, PTHREAD_SCOPE_SYSTEM);
 335 #endif /* PTHREAD_SCOPE_SYSTEM */
 336
 337 #ifdef G_THREADS_IMPL_POSIX
 338   posix_check_cmd (pthread_attr_setdetachstate (&attr,
 339           joinable ? PTHREAD_CREATE_JOINABLE : PTHREAD_CREATE_DETACHED));
 340 #endif /* G_THREADS_IMPL_POSIX */
 341
 342 #ifdef HAVE_PRIORITIES
 343 # ifdef G_THREADS_IMPL_POSIX
 344   {
 345     struct sched_param sched;
 346     posix_check_cmd (pthread_attr_getschedparam (&attr, &sched));
 347     sched.sched_priority = g_thread_priority_map [priority];
 348     posix_check_cmd_prio (pthread_attr_setschedparam (&attr, &sched));
 349   }
 350 # else /* G_THREADS_IMPL_DCE */
 351   posix_check_cmd_prio
 352     (pthread_attr_setprio (&attr, g_thread_priority_map [priority]));
 353 # endif /* G_THREADS_IMPL_DCE */
 354 #endif /* HAVE_PRIORITIES */
 355   ret = posix_error (pthread_create (thread, &attr,
 356                                      (void* (*)(void*))thread_func, arg));
 357
 358   posix_check_cmd (pthread_attr_destroy (&attr));
 359
 360   if (ret == EAGAIN)
 361     {
 362       g_set_error (error, G_THREAD_ERROR, G_THREAD_ERROR_AGAIN,
 363                    "Error creating thread: %s", g_strerror (ret));
 364       return;
 365     }
 366
 367   posix_check_err (ret, "pthread_create");
 368
 369 #ifdef G_THREADS_IMPL_DCE
 370   if (!joinable)
 371     posix_check_cmd (pthread_detach (thread));
 372 #endif /* G_THREADS_IMPL_DCE */
 373 }
 374
 375 static void
 376 g_thread_yield_posix_impl (void)
 377 {
 378   POSIX_YIELD_FUNC;
 379 }
 380
 381 static void
 382 g_thread_join_posix_impl (gpointer thread)
 383 {
 384   gpointer ignore;
 385   posix_check_cmd (pthread_join (*(pthread_t*)thread, &ignore));
 386 }
 387
 388 static void
 389 g_thread_exit_posix_impl (void)
 390 {
 391   pthread_exit (NULL);
 392 }
 393
 394 static void
 395 g_thread_set_priority_posix_impl (gpointer thread, GThreadPriority priority)
 396 {
 397   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 398   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 399 #ifdef HAVE_PRIORITIES
 400 # ifdef G_THREADS_IMPL_POSIX
 401   {
 402     struct sched_param sched;
 403     int policy;
 404     posix_check_cmd (pthread_getschedparam (*(pthread_t*)thread, &policy,
 405                                             &sched));
 406     sched.sched_priority = g_thread_priority_map [priority];
 407     posix_check_cmd_prio (pthread_setschedparam (*(pthread_t*)thread, policy,
 408                                                  &sched));
 409   }
 410 # else /* G_THREADS_IMPL_DCE */
 411   posix_check_cmd_prio (pthread_setprio (*(pthread_t*)thread,
 412                                          g_thread_priority_map [priority]));
 413 # endif
 414 #endif /* HAVE_PRIORITIES */
 415 }
 416
 417 static void
 418 g_thread_self_posix_impl (gpointer thread)
 419 {
 420   *(pthread_t*)thread = pthread_self();
 421 }
 422
 423 static gboolean
 424 g_thread_equal_posix_impl (gpointer thread1, gpointer thread2)
 425 {
 426   return (pthread_equal (*(pthread_t*)thread1, *(pthread_t*)thread2) != 0);
 427 }
 428
 429 #ifdef USE_CLOCK_GETTIME
 430 static guint64
 431 gettime (void)
 432 {
 433   struct timespec tv;
 434
 435   clock_gettime (posix_clock, &tv);
 436
 437   return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_nsec;
 438 }
 439 static guint64 (*g_thread_gettime_impl)(void) = gettime;
 440 #else
 441 static guint64 (*g_thread_gettime_impl)(void) = 0;
 442 #endif
 443
 444 static GThreadFunctions g_thread_functions_for_glib_use_default =
 445 {
 446   g_mutex_new_posix_impl,
 447   (void (*)(GMutex *)) pthread_mutex_lock,
 448   g_mutex_trylock_posix_impl,
 449   (void (*)(GMutex *)) pthread_mutex_unlock,
 450   g_mutex_free_posix_impl,
 451   g_cond_new_posix_impl,
 452   (void (*)(GCond *)) pthread_cond_signal,
 453   (void (*)(GCond *)) pthread_cond_broadcast,
 454   (void (*)(GCond *, GMutex *)) pthread_cond_wait,
 455   g_cond_timed_wait_posix_impl,
 456   g_cond_free_posix_impl,
 457   g_private_new_posix_impl,
 458   g_private_get_posix_impl,
 459   g_private_set_posix_impl,
 460   g_thread_create_posix_impl,
 461   g_thread_yield_posix_impl,
 462   g_thread_join_posix_impl,
 463   g_thread_exit_posix_impl,
 464   g_thread_set_priority_posix_impl,
 465   g_thread_self_posix_impl,
 466   g_thread_equal_posix_impl
 467 };