glib/gthread.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: MT safety related functions
   5  * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
   6  *                Owen Taylor
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the
  20  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21  * Boston, MA 02111-1307, USA.
  22  */
  23
  24 /*
  25  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  26  * file for a list of people on the GLib Team.  See the ChangeLog
  27  * files for a list of changes.  These files are distributed with
  28  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  29  */
  30
  31 /*
  32  * MT safe
  33  */
  34
  35 #include "config.h"
  36
  37 #include "glib.h"
  38 #include "gthreadprivate.h"
  39
  40 #ifdef HAVE_UNISTD_H
  41 #include <unistd.h>
  42 #endif
  43
  44 #ifndef G_OS_WIN32
  45 #include <sys/time.h>
  46 #include <time.h>
  47 #else
  48 #include <windows.h>
  49 #endif /* G_OS_WIN32 */
  50
  51 #include <string.h>
  52
  53 #include "galias.h"
  54
  55 GQuark
  56 g_thread_error_quark (void)
  57 {
  58   return g_quark_from_static_string ("g_thread_error");
  59 }
  60
  61 /* Keep this in sync with GRealThread in gmain.c! */
  62 typedef struct _GRealThread GRealThread;
  63 struct  _GRealThread
  64 {
  65   GThread thread;
  66   gpointer private_data;
  67   GRealThread *next;
  68   gpointer retval;
  69   GSystemThread system_thread;
  70 };
  71
  72 typedef struct _GStaticPrivateNode GStaticPrivateNode;
  73 struct _GStaticPrivateNode
  74 {
  75   gpointer       data;
  76   GDestroyNotify destroy;
  77 };
  78
  79 static void    g_thread_cleanup (gpointer data);
  80 static void    g_thread_fail (void);
  81 static guint64 gettime (void);
  82
  83 guint64        (*g_thread_gettime) (void) = gettime;
  84
  85 /* Global variables */
  86
  87 static GSystemThread zero_thread; /* This is initialized to all zero */
  88 gboolean g_thread_use_default_impl = TRUE;
  89 gboolean g_threads_got_initialized = FALSE;
  90
  91 GThreadFunctions g_thread_functions_for_glib_use = {
  92   (GMutex*(*)())g_thread_fail,                 /* mutex_new */
  93   NULL,                                        /* mutex_lock */
  94   NULL,                                        /* mutex_trylock */
  95   NULL,                                        /* mutex_unlock */
  96   NULL,                                        /* mutex_free */
  97   (GCond*(*)())g_thread_fail,                  /* cond_new */
  98   NULL,                                        /* cond_signal */
  99   NULL,                                        /* cond_broadcast */
 100   NULL,                                        /* cond_wait */
 101   NULL,                                        /* cond_timed_wait  */
 102   NULL,                                        /* cond_free */
 103   (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
 104   NULL,                                        /* private_get */
 105   NULL,                                        /* private_set */
 106   (void(*)(GThreadFunc, gpointer, gulong,
 107            gboolean, gboolean, GThreadPriority,
 108            gpointer, GError**))g_thread_fail,  /* thread_create */
 109   NULL,                                        /* thread_yield */
 110   NULL,                                        /* thread_join */
 111   NULL,                                        /* thread_exit */
 112   NULL,                                        /* thread_set_priority */
 113   NULL,                                        /* thread_self */
 114   NULL                                         /* thread_equal */
 115 };
 116
 117 /* Local data */
 118
 119 static GMutex   *g_once_mutex = NULL;
 120 static GCond    *g_once_cond = NULL;
 121 static GPrivate *g_thread_specific_private = NULL;
 122 static GRealThread *g_thread_all_threads = NULL;
 123 static GSList   *g_thread_free_indeces = NULL;
 124
 125 G_LOCK_DEFINE_STATIC (g_thread);
 126
 127 #ifdef G_THREADS_ENABLED
 128 /* This must be called only once, before any threads are created.
 129  * It will only be called from g_thread_init() in -lgthread.
 130  */
 131 void
 132 g_thread_init_glib (void)
 133 {
 134   /* We let the main thread (the one that calls g_thread_init) inherit
 135    * the static_private data set before calling g_thread_init
 136    */
 137   GRealThread* main_thread = (GRealThread*) g_thread_self ();
 138
 139   /* mutex and cond creation works without g_threads_got_initialized */
 140   g_once_mutex = g_mutex_new ();
 141   g_once_cond = g_cond_new ();
 142
 143   /* we may only create mutex and cond in here */
 144   _g_mem_thread_init_noprivate_nomessage ();
 145
 146   /* setup the basic threading system */
 147   g_threads_got_initialized = TRUE;
 148   g_thread_specific_private = g_private_new (g_thread_cleanup);
 149   g_private_set (g_thread_specific_private, main_thread);
 150   G_THREAD_UF (thread_self, (&main_thread->system_thread));
 151
 152   /* complete memory system initialization, g_private_*() works now */
 153   _g_slice_thread_init_nomessage ();
 154
 155   /* accomplish log system initialization to enable messaging */
 156   _g_messages_thread_init_nomessage ();
 157
 158   /* we may run full-fledged initializers from here */
 159   _g_atomic_thread_init ();
 160   _g_convert_thread_init ();
 161   _g_rand_thread_init ();
 162   _g_main_thread_init ();
 163   _g_utils_thread_init ();
 164 #ifdef G_OS_WIN32
 165   _g_win32_thread_init ();
 166 #endif
 167 }
 168 #endif /* G_THREADS_ENABLED */
 169
 170 gpointer
 171 g_once_impl (GOnce       *once,
 172              GThreadFunc  func,
 173              gpointer     arg)
 174 {
 175   g_mutex_lock (g_once_mutex);
 176
 177   while (once->status == G_ONCE_STATUS_PROGRESS)
 178     g_cond_wait (g_once_cond, g_once_mutex);
 179
 180   if (once->status != G_ONCE_STATUS_READY)
 181     {
 182       once->status = G_ONCE_STATUS_PROGRESS;
 183       g_mutex_unlock (g_once_mutex);
 184
 185       once->retval = func (arg);
 186
 187       g_mutex_lock (g_once_mutex);
 188       once->status = G_ONCE_STATUS_READY;
 189       g_cond_broadcast (g_once_cond);
 190     }
 191
 192   g_mutex_unlock (g_once_mutex);
 193
 194   return once->retval;
 195 }
 196
 197 void
 198 g_static_mutex_init (GStaticMutex *mutex)
 199 {
 200   static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
 201
 202   g_return_if_fail (mutex);
 203
 204   *mutex = init_mutex;
 205 }
 206
 207 GMutex *
 208 g_static_mutex_get_mutex_impl (GMutex** mutex)
 209 {
 210   if (!g_thread_supported ())
 211     return NULL;
 212
 213   g_assert (g_once_mutex);
 214
 215   g_mutex_lock (g_once_mutex);
 216
 217   if (!(*mutex))
 218     g_atomic_pointer_set (mutex, g_mutex_new());
 219
 220   g_mutex_unlock (g_once_mutex);
 221
 222   return *mutex;
 223 }
 224
 225 void
 226 g_static_mutex_free (GStaticMutex* mutex)
 227 {
 228   GMutex **runtime_mutex;
 229
 230   g_return_if_fail (mutex);
 231
 232   /* The runtime_mutex is the first (or only) member of GStaticMutex,
 233    * see both versions (of glibconfig.h) in configure.in. Note, that
 234    * this variable is NULL, if g_thread_init() hasn't been called or
 235    * if we're using the default thread implementation and it provides
 236    * static mutexes. */
 237   runtime_mutex = ((GMutex**)mutex);
 238
 239   if (*runtime_mutex)
 240     g_mutex_free (*runtime_mutex);
 241
 242   *runtime_mutex = NULL;
 243 }
 244
 245 void
 246 g_static_rec_mutex_init (GStaticRecMutex *mutex)
 247 {
 248   static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
 249
 250   g_return_if_fail (mutex);
 251
 252   *mutex = init_mutex;
 253 }
 254
 255 void
 256 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
 257 {
 258   GSystemThread self;
 259
 260   g_return_if_fail (mutex);
 261
 262   if (!g_thread_supported ())
 263     return;
 264
 265   G_THREAD_UF (thread_self, (&self));
 266
 267   if (g_system_thread_equal (self, mutex->owner))
 268     {
 269       mutex->depth++;
 270       return;
 271     }
 272   g_static_mutex_lock (&mutex->mutex);
 273   g_system_thread_assign (mutex->owner, self);
 274   mutex->depth = 1;
 275 }
 276
 277 gboolean
 278 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
 279 {
 280   GSystemThread self;
 281
 282   g_return_val_if_fail (mutex, FALSE);
 283
 284   if (!g_thread_supported ())
 285     return TRUE;
 286
 287   G_THREAD_UF (thread_self, (&self));
 288
 289   if (g_system_thread_equal (self, mutex->owner))
 290     {
 291       mutex->depth++;
 292       return TRUE;
 293     }
 294
 295   if (!g_static_mutex_trylock (&mutex->mutex))
 296     return FALSE;
 297
 298   g_system_thread_assign (mutex->owner, self);
 299   mutex->depth = 1;
 300   return TRUE;
 301 }
 302
 303 void
 304 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
 305 {
 306   g_return_if_fail (mutex);
 307
 308   if (!g_thread_supported ())
 309     return;
 310
 311   if (mutex->depth > 1)
 312     {
 313       mutex->depth--;
 314       return;
 315     }
 316   g_system_thread_assign (mutex->owner, zero_thread);
 317   g_static_mutex_unlock (&mutex->mutex);
 318 }
 319
 320 void
 321 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 322                                 guint            depth)
 323 {
 324   GSystemThread self;
 325   g_return_if_fail (mutex);
 326
 327   if (!g_thread_supported ())
 328     return;
 329
 330   if (depth == 0)
 331     return;
 332
 333   G_THREAD_UF (thread_self, (&self));
 334
 335   if (g_system_thread_equal (self, mutex->owner))
 336     {
 337       mutex->depth += depth;
 338       return;
 339     }
 340   g_static_mutex_lock (&mutex->mutex);
 341   g_system_thread_assign (mutex->owner, self);
 342   mutex->depth = depth;
 343 }
 344
 345 guint
 346 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
 347 {
 348   guint depth;
 349
 350   g_return_val_if_fail (mutex, 0);
 351
 352   if (!g_thread_supported ())
 353     return 1;
 354
 355   depth = mutex->depth;
 356
 357   g_system_thread_assign (mutex->owner, zero_thread);
 358   mutex->depth = 0;
 359   g_static_mutex_unlock (&mutex->mutex);
 360
 361   return depth;
 362 }
 363
 364 void
 365 g_static_rec_mutex_free (GStaticRecMutex *mutex)
 366 {
 367   g_return_if_fail (mutex);
 368
 369   g_static_mutex_free (&mutex->mutex);
 370 }
 371
 372 void
 373 g_static_private_init (GStaticPrivate *private_key)
 374 {
 375   private_key->index = 0;
 376 }
 377
 378 gpointer
 379 g_static_private_get (GStaticPrivate *private_key)
 380 {
 381   GRealThread *self = (GRealThread*) g_thread_self ();
 382   GArray *array;
 383
 384   array = self->private_data;
 385   if (!array)
 386     return NULL;
 387
 388   if (!private_key->index)
 389     return NULL;
 390   else if (private_key->index <= array->len)
 391     return g_array_index (array, GStaticPrivateNode,
 392                           private_key->index - 1).data;
 393   else
 394     return NULL;
 395 }
 396
 397 void
 398 g_static_private_set (GStaticPrivate *private_key,
 399                       gpointer        data,
 400                       GDestroyNotify  notify)
 401 {
 402   GRealThread *self = (GRealThread*) g_thread_self ();
 403   GArray *array;
 404   static guint next_index = 0;
 405   GStaticPrivateNode *node;
 406
 407   array = self->private_data;
 408   if (!array)
 409     {
 410       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
 411       self->private_data = array;
 412     }
 413
 414   if (!private_key->index)
 415     {
 416       G_LOCK (g_thread);
 417
 418       if (!private_key->index)
 419         {
 420           if (g_thread_free_indeces)
 421             {
 422               private_key->index =
 423                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
 424               g_thread_free_indeces =
 425                 g_slist_delete_link (g_thread_free_indeces,
 426                                      g_thread_free_indeces);
 427             }
 428           else
 429             private_key->index = ++next_index;
 430         }
 431
 432       G_UNLOCK (g_thread);
 433     }
 434
 435   if (private_key->index > array->len)
 436     g_array_set_size (array, private_key->index);
 437
 438   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
 439   if (node->destroy)
 440     {
 441       gpointer ddata = node->data;
 442       GDestroyNotify ddestroy = node->destroy;
 443
 444       node->data = data;
 445       node->destroy = notify;
 446
 447       ddestroy (ddata);
 448     }
 449   else
 450     {
 451       node->data = data;
 452       node->destroy = notify;
 453     }
 454 }
 455
 456 void
 457 g_static_private_free (GStaticPrivate *private_key)
 458 {
 459   guint index = private_key->index;
 460   GRealThread *thread;
 461
 462   if (!index)
 463     return;
 464
 465   private_key->index = 0;
 466
 467   G_LOCK (g_thread);
 468
 469   thread = g_thread_all_threads;
 470   while (thread)
 471     {
 472       GArray *array = thread->private_data;
 473       thread = thread->next;
 474
 475       if (array && index <= array->len)
 476         {
 477           GStaticPrivateNode *node = &g_array_index (array,
 478                                                      GStaticPrivateNode,
 479                                                      index - 1);
 480           gpointer ddata = node->data;
 481           GDestroyNotify ddestroy = node->destroy;
 482
 483           node->data = NULL;
 484           node->destroy = NULL;
 485
 486           if (ddestroy)
 487             {
 488               G_UNLOCK (g_thread);
 489               ddestroy (ddata);
 490               G_LOCK (g_thread);
 491               }
 492         }
 493     }
 494   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
 495                                            GUINT_TO_POINTER (index));
 496   G_UNLOCK (g_thread);
 497 }
 498
 499 static void
 500 g_thread_cleanup (gpointer data)
 501 {
 502   if (data)
 503     {
 504       GRealThread* thread = data;
 505       if (thread->private_data)
 506         {
 507           GArray* array = thread->private_data;
 508           guint i;
 509
 510           for (i = 0; i < array->len; i++ )
 511             {
 512               GStaticPrivateNode *node =
 513                 &g_array_index (array, GStaticPrivateNode, i);
 514               if (node->destroy)
 515                 node->destroy (node->data);
 516             }
 517           g_array_free (array, TRUE);
 518         }
 519
 520       /* We only free the thread structure, if it isn't joinable. If
 521          it is, the structure is freed in g_thread_join */
 522       if (!thread->thread.joinable)
 523         {
 524           GRealThread *t, *p;
 525
 526           G_LOCK (g_thread);
 527           for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 528             {
 529               if (t == thread)
 530                 {
 531                   if (p)
 532                     p->next = t->next;
 533                   else
 534                     g_thread_all_threads = t->next;
 535                   break;
 536                 }
 537             }
 538           G_UNLOCK (g_thread);
 539
 540           /* Just to make sure, this isn't used any more */
 541           g_system_thread_assign (thread->system_thread, zero_thread);
 542           g_free (thread);
 543         }
 544     }
 545 }
 546
 547 static void
 548 g_thread_fail (void)
 549 {
 550   g_error ("The thread system is not yet initialized.");
 551 }
 552
 553 #define G_NSEC_PER_SEC 1000000000
 554
 555 static guint64
 556 gettime (void)
 557 {
 558 #ifdef G_OS_WIN32
 559   guint64 v;
 560
 561   /* Returns 100s of nanoseconds since start of 1601 */
 562   GetSystemTimeAsFileTime ((FILETIME *)&v);
 563
 564   /* Offset to Unix epoch */
 565   v -= G_GINT64_CONSTANT (116444736000000000);
 566   /* Convert to nanoseconds */
 567   v *= 100;
 568
 569   return v;
 570 #else
 571   struct timeval tv;
 572
 573   gettimeofday (&tv, NULL);
 574
 575   return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 576 #endif
 577 }
 578
 579 static gpointer
 580 g_thread_create_proxy (gpointer data)
 581 {
 582   GRealThread* thread = data;
 583
 584   g_assert (data);
 585
 586   /* This has to happen before G_LOCK, as that might call g_thread_self */
 587   g_private_set (g_thread_specific_private, data);
 588
 589   /* the lock makes sure, that thread->system_thread is written,
 590      before thread->thread.func is called. See g_thread_create. */
 591   G_LOCK (g_thread);
 592   G_UNLOCK (g_thread);
 593
 594   thread->retval = thread->thread.func (thread->thread.data);
 595
 596   return NULL;
 597 }
 598
 599 GThread*
 600 g_thread_create_full (GThreadFunc                func,
 601                       gpointer           data,
 602                       gulong             stack_size,
 603                       gboolean           joinable,
 604                       gboolean           bound,
 605                       GThreadPriority    priority,
 606                       GError                **error)
 607 {
 608   GRealThread* result;
 609   GError *local_error = NULL;
 610   g_return_val_if_fail (func, NULL);
 611   g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
 612   g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
 613
 614   result = g_new0 (GRealThread, 1);
 615
 616   result->thread.joinable = joinable;
 617   result->thread.priority = priority;
 618   result->thread.func = func;
 619   result->thread.data = data;
 620   result->private_data = NULL;
 621   G_LOCK (g_thread);
 622   G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
 623                                stack_size, joinable, bound, priority,
 624                                &result->system_thread, &local_error));
 625   result->next = g_thread_all_threads;
 626   g_thread_all_threads = result;
 627   G_UNLOCK (g_thread);
 628
 629   if (local_error)
 630     {
 631       g_propagate_error (error, local_error);
 632       g_free (result);
 633       return NULL;
 634     }
 635
 636   return (GThread*) result;
 637 }
 638
 639 void
 640 g_thread_exit (gpointer retval)
 641 {
 642   GRealThread* real = (GRealThread*) g_thread_self ();
 643   real->retval = retval;
 644   G_THREAD_CF (thread_exit, (void)0, ());
 645 }
 646
 647 gpointer
 648 g_thread_join (GThread* thread)
 649 {
 650   GRealThread* real = (GRealThread*) thread;
 651   GRealThread *p, *t;
 652   gpointer retval;
 653
 654   g_return_val_if_fail (thread, NULL);
 655   g_return_val_if_fail (thread->joinable, NULL);
 656   g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
 657                                                 zero_thread), NULL);
 658
 659   G_THREAD_UF (thread_join, (&real->system_thread));
 660
 661   retval = real->retval;
 662
 663   G_LOCK (g_thread);
 664   for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 665     {
 666       if (t == (GRealThread*) thread)
 667         {
 668           if (p)
 669             p->next = t->next;
 670           else
 671             g_thread_all_threads = t->next;
 672           break;
 673         }
 674     }
 675   G_UNLOCK (g_thread);
 676
 677   /* Just to make sure, this isn't used any more */
 678   thread->joinable = 0;
 679   g_system_thread_assign (real->system_thread, zero_thread);
 680
 681   /* the thread structure for non-joinable threads is freed upon
 682      thread end. We free the memory here. This will leave a loose end,
 683      if a joinable thread is not joined. */
 684
 685   g_free (thread);
 686
 687   return retval;
 688 }
 689
 690 void
 691 g_thread_set_priority (GThread* thread,
 692                        GThreadPriority priority)
 693 {
 694   GRealThread* real = (GRealThread*) thread;
 695
 696   g_return_if_fail (thread);
 697   g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
 698   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 699   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 700
 701   thread->priority = priority;
 702
 703   G_THREAD_CF (thread_set_priority, (void)0,
 704                (&real->system_thread, priority));
 705 }
 706
 707 GThread*
 708 g_thread_self (void)
 709 {
 710   GRealThread* thread = g_private_get (g_thread_specific_private);
 711
 712   if (!thread)
 713     {
 714       /* If no thread data is available, provide and set one.  This
 715          can happen for the main thread and for threads, that are not
 716          created by GLib. */
 717       thread = g_new0 (GRealThread, 1);
 718       thread->thread.joinable = FALSE; /* This is a save guess */
 719       thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
 720                                                              just a guess */
 721       thread->thread.func = NULL;
 722       thread->thread.data = NULL;
 723       thread->private_data = NULL;
 724
 725       if (g_thread_supported ())
 726         G_THREAD_UF (thread_self, (&thread->system_thread));
 727
 728       g_private_set (g_thread_specific_private, thread);
 729
 730       G_LOCK (g_thread);
 731       thread->next = g_thread_all_threads;
 732       g_thread_all_threads = thread;
 733       G_UNLOCK (g_thread);
 734     }
 735
 736   return (GThread*)thread;
 737 }
 738
 739 void
 740 g_static_rw_lock_init (GStaticRWLock* lock)
 741 {
 742   static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
 743
 744   g_return_if_fail (lock);
 745
 746   *lock = init_lock;
 747 }
 748
 749 inline static void
 750 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
 751 {
 752   if (!*cond)
 753       *cond = g_cond_new ();
 754   g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
 755 }
 756
 757 inline static void
 758 g_static_rw_lock_signal (GStaticRWLock* lock)
 759 {
 760   if (lock->want_to_write && lock->write_cond)
 761     g_cond_signal (lock->write_cond);
 762   else if (lock->want_to_read && lock->read_cond)
 763     g_cond_broadcast (lock->read_cond);
 764 }
 765
 766 void
 767 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
 768 {
 769   g_return_if_fail (lock);
 770
 771   if (!g_threads_got_initialized)
 772     return;
 773
 774   g_static_mutex_lock (&lock->mutex);
 775   lock->want_to_read++;
 776   while (lock->have_writer || lock->want_to_write)
 777     g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
 778   lock->want_to_read--;
 779   lock->read_counter++;
 780   g_static_mutex_unlock (&lock->mutex);
 781 }
 782
 783 gboolean
 784 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
 785 {
 786   gboolean ret_val = FALSE;
 787
 788   g_return_val_if_fail (lock, FALSE);
 789
 790   if (!g_threads_got_initialized)
 791     return TRUE;
 792
 793   g_static_mutex_lock (&lock->mutex);
 794   if (!lock->have_writer && !lock->want_to_write)
 795     {
 796       lock->read_counter++;
 797       ret_val = TRUE;
 798     }
 799   g_static_mutex_unlock (&lock->mutex);
 800   return ret_val;
 801 }
 802
 803 void
 804 g_static_rw_lock_reader_unlock  (GStaticRWLock* lock)
 805 {
 806   g_return_if_fail (lock);
 807
 808   if (!g_threads_got_initialized)
 809     return;
 810
 811   g_static_mutex_lock (&lock->mutex);
 812   lock->read_counter--;
 813   if (lock->read_counter == 0)
 814     g_static_rw_lock_signal (lock);
 815   g_static_mutex_unlock (&lock->mutex);
 816 }
 817
 818 void
 819 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
 820 {
 821   g_return_if_fail (lock);
 822
 823   if (!g_threads_got_initialized)
 824     return;
 825
 826   g_static_mutex_lock (&lock->mutex);
 827   lock->want_to_write++;
 828   while (lock->have_writer || lock->read_counter)
 829     g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
 830   lock->want_to_write--;
 831   lock->have_writer = TRUE;
 832   g_static_mutex_unlock (&lock->mutex);
 833 }
 834
 835 gboolean
 836 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
 837 {
 838   gboolean ret_val = FALSE;
 839
 840   g_return_val_if_fail (lock, FALSE);
 841
 842   if (!g_threads_got_initialized)
 843     return TRUE;
 844
 845   g_static_mutex_lock (&lock->mutex);
 846   if (!lock->have_writer && !lock->read_counter)
 847     {
 848       lock->have_writer = TRUE;
 849       ret_val = TRUE;
 850     }
 851   g_static_mutex_unlock (&lock->mutex);
 852   return ret_val;
 853 }
 854
 855 void
 856 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
 857 {
 858   g_return_if_fail (lock);
 859
 860   if (!g_threads_got_initialized)
 861     return;
 862
 863   g_static_mutex_lock (&lock->mutex);
 864   lock->have_writer = FALSE;
 865   g_static_rw_lock_signal (lock);
 866   g_static_mutex_unlock (&lock->mutex);
 867 }
 868
 869 void
 870 g_static_rw_lock_free (GStaticRWLock* lock)
 871 {
 872   g_return_if_fail (lock);
 873
 874   if (lock->read_cond)
 875     {
 876       g_cond_free (lock->read_cond);
 877       lock->read_cond = NULL;
 878     }
 879   if (lock->write_cond)
 880     {
 881       g_cond_free (lock->write_cond);
 882       lock->write_cond = NULL;
 883     }
 884   g_static_mutex_free (&lock->mutex);
 885 }
 886
 887 /**
 888  * g_thread_foreach
 889  * @thread_func: function to call for all GThread structures
 890  * @user_data:   second argument to @thread_func
 891  *
 892  * Call @thread_func on all existing #GThread structures. Note that
 893  * threads may decide to exit while @thread_func is running, so
 894  * without intimate knowledge about the lifetime of foreign threads,
 895  * @thread_func shouldn't access the GThread* pointer passed in as
 896  * first argument. However, @thread_func will not be called for threads
 897  * which are known to have exited already.
 898  *
 899  * Due to thread lifetime checks, this function has an execution complexity
 900  * which is quadratic in the number of existing threads.
 901  *
 902  * Since: 2.10
 903  */
 904 void
 905 g_thread_foreach (GFunc    thread_func,
 906                   gpointer user_data)
 907 {
 908   GSList *slist = NULL;
 909   GRealThread *thread;
 910   g_return_if_fail (thread_func != NULL);
 911   /* snapshot the list of threads for iteration */
 912   G_LOCK (g_thread);
 913   for (thread = g_thread_all_threads; thread; thread = thread->next)
 914     slist = g_slist_prepend (slist, thread);
 915   G_UNLOCK (g_thread);
 916   /* walk the list, skipping non-existant threads */
 917   while (slist)
 918     {
 919       GSList *node = slist;
 920       slist = node->next;
 921       /* check whether the current thread still exists */
 922       G_LOCK (g_thread);
 923       for (thread = g_thread_all_threads; thread; thread = thread->next)
 924         if (thread == node->data)
 925           break;
 926       G_UNLOCK (g_thread);
 927       if (thread)
 928         thread_func (thread, user_data);
 929       g_slist_free_1 (node);
 930     }
 931 }
 932
 933 #define __G_THREAD_C__
 934 #include "galiasdef.c"