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 #ifdef HAVE_UNISTD_H
  38 #include <unistd.h>
  39 #endif
  40
  41 #include <string.h>
  42
  43 #include "glib.h"
  44 #include "gthreadinit.h"
  45 #include "galias.h"
  46
  47 #if GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P
  48 # define g_system_thread_equal_simple(thread1, thread2)                 \
  49    ((thread1).dummy_pointer == (thread2).dummy_pointer)
  50 # define g_system_thread_assign(dest, src)                              \
  51    ((dest).dummy_pointer = (src).dummy_pointer)
  52 #else /* GLIB_SIZEOF_SYSTEM_THREAD != SIZEOF_VOID_P */
  53 # define g_system_thread_equal_simple(thread1, thread2)                 \
  54    (memcmp (&(thread1), &(thread2), GLIB_SIZEOF_SYSTEM_THREAD) == 0)
  55 # define g_system_thread_assign(dest, src)                              \
  56    (memcpy (&(dest), &(src), GLIB_SIZEOF_SYSTEM_THREAD))
  57 #endif /* GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P */
  58
  59 #define g_system_thread_equal(thread1, thread2)                         \
  60   (g_thread_functions_for_glib_use.thread_equal ?                       \
  61    g_thread_functions_for_glib_use.thread_equal (&(thread1), &(thread2)) :\
  62    g_system_thread_equal_simple((thread1), (thread2)))
  63
  64 GQuark
  65 g_thread_error_quark (void)
  66 {
  67   return g_quark_from_static_string ("g_thread_error");
  68 }
  69
  70 /* Keep this in sync with GRealThread in gmain.c! */
  71 typedef struct _GRealThread GRealThread;
  72 struct  _GRealThread
  73 {
  74   GThread thread;
  75   gpointer private_data;
  76   GRealThread *next;
  77   gpointer retval;
  78   GSystemThread system_thread;
  79 };
  80
  81 typedef struct _GStaticPrivateNode GStaticPrivateNode;
  82 struct _GStaticPrivateNode
  83 {
  84   gpointer       data;
  85   GDestroyNotify destroy;
  86 };
  87
  88 static void g_thread_cleanup (gpointer data);
  89 static void g_thread_fail (void);
  90
  91 /* Global variables */
  92
  93 static GSystemThread zero_thread; /* This is initialized to all zero */
  94 gboolean g_thread_use_default_impl = TRUE;
  95 gboolean g_threads_got_initialized = FALSE;
  96
  97 GThreadFunctions g_thread_functions_for_glib_use = {
  98   (GMutex*(*)())g_thread_fail,                 /* mutex_new */
  99   NULL,                                        /* mutex_lock */
 100   NULL,                                        /* mutex_trylock */
 101   NULL,                                        /* mutex_unlock */
 102   NULL,                                        /* mutex_free */
 103   (GCond*(*)())g_thread_fail,                  /* cond_new */
 104   NULL,                                        /* cond_signal */
 105   NULL,                                        /* cond_broadcast */
 106   NULL,                                        /* cond_wait */
 107   NULL,                                        /* cond_timed_wait  */
 108   NULL,                                        /* cond_free */
 109   (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
 110   NULL,                                        /* private_get */
 111   NULL,                                        /* private_set */
 112   (void(*)(GThreadFunc, gpointer, gulong,
 113            gboolean, gboolean, GThreadPriority,
 114            gpointer, GError**))g_thread_fail,  /* thread_create */
 115   NULL,                                        /* thread_yield */
 116   NULL,                                        /* thread_join */
 117   NULL,                                        /* thread_exit */
 118   NULL,                                        /* thread_set_priority */
 119   NULL                                         /* thread_self */
 120 };
 121
 122 /* Local data */
 123
 124 static GMutex   *g_once_mutex = NULL;
 125 static GCond    *g_once_cond = NULL;
 126 static GPrivate *g_thread_specific_private = NULL;
 127 static GRealThread *g_thread_all_threads = NULL;
 128 static GSList   *g_thread_free_indeces = NULL;
 129
 130 G_LOCK_DEFINE_STATIC (g_thread);
 131
 132 #ifdef G_THREADS_ENABLED
 133 /* This must be called only once, before any threads are created.
 134  * It will only be called from g_thread_init() in -lgthread.
 135  */
 136 void
 137 g_thread_init_glib (void)
 138 {
 139   /* We let the main thread (the one that calls g_thread_init) inherit
 140    * the static_private data set before calling g_thread_init
 141    */
 142   GRealThread* main_thread = (GRealThread*) g_thread_self ();
 143
 144   /* mutex and cond creation works without g_threads_got_initialized */
 145   g_once_mutex = g_mutex_new ();
 146   g_once_cond = g_cond_new ();
 147
 148   /* we may only create mutex and cond in here */
 149   _g_mem_thread_init_noprivate_nomessage ();
 150
 151   /* setup the basic threading system */
 152   g_threads_got_initialized = TRUE;
 153   g_thread_specific_private = g_private_new (g_thread_cleanup);
 154   g_private_set (g_thread_specific_private, main_thread);
 155   G_THREAD_UF (thread_self, (&main_thread->system_thread));
 156
 157   /* complete memory system initialization, g_private_*() works now */
 158   _g_slice_thread_init_nomessage ();
 159
 160   /* accomplish log system initialization to enable messaging */
 161   _g_messages_thread_init_nomessage ();
 162
 163   /* we may run full-fledged initializers from here */
 164   _g_convert_thread_init ();
 165   _g_rand_thread_init ();
 166   _g_main_thread_init ();
 167   _g_atomic_thread_init ();
 168   _g_utils_thread_init ();
 169 #ifdef G_OS_WIN32
 170   _g_win32_thread_init ();
 171 #endif
 172 }
 173 #endif /* G_THREADS_ENABLED */
 174
 175 gpointer
 176 g_once_impl (GOnce       *once,
 177              GThreadFunc  func,
 178              gpointer     arg)
 179 {
 180   g_mutex_lock (g_once_mutex);
 181
 182   while (once->status == G_ONCE_STATUS_PROGRESS)
 183     g_cond_wait (g_once_cond, g_once_mutex);
 184
 185   if (once->status != G_ONCE_STATUS_READY)
 186     {
 187       once->status = G_ONCE_STATUS_PROGRESS;
 188       g_mutex_unlock (g_once_mutex);
 189
 190       once->retval = func (arg);
 191
 192       g_mutex_lock (g_once_mutex);
 193       once->status = G_ONCE_STATUS_READY;
 194       g_cond_broadcast (g_once_cond);
 195     }
 196
 197   g_mutex_unlock (g_once_mutex);
 198
 199   return once->retval;
 200 }
 201
 202 void
 203 g_static_mutex_init (GStaticMutex *mutex)
 204 {
 205   static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
 206
 207   g_return_if_fail (mutex);
 208
 209   *mutex = init_mutex;
 210 }
 211
 212 GMutex *
 213 g_static_mutex_get_mutex_impl (GMutex** mutex)
 214 {
 215   if (!g_thread_supported ())
 216     return NULL;
 217
 218   g_assert (g_once_mutex);
 219
 220   g_mutex_lock (g_once_mutex);
 221
 222   if (!(*mutex))
 223     {
 224       GMutex *new_mutex = g_mutex_new ();
 225
 226       /* The following is a memory barrier to avoid the write
 227        * to *new_mutex being reordered to after writing *mutex */
 228       g_mutex_lock (new_mutex);
 229       g_mutex_unlock (new_mutex);
 230
 231       *mutex = new_mutex;
 232     }
 233
 234   g_mutex_unlock (g_once_mutex);
 235
 236   return *mutex;
 237 }
 238
 239 void
 240 g_static_mutex_free (GStaticMutex* mutex)
 241 {
 242   GMutex **runtime_mutex;
 243
 244   g_return_if_fail (mutex);
 245
 246   /* The runtime_mutex is the first (or only) member of GStaticMutex,
 247    * see both versions (of glibconfig.h) in configure.in */
 248   runtime_mutex = ((GMutex**)mutex);
 249
 250   if (*runtime_mutex)
 251     g_mutex_free (*runtime_mutex);
 252
 253   *runtime_mutex = NULL;
 254 }
 255
 256 void
 257 g_static_rec_mutex_init (GStaticRecMutex *mutex)
 258 {
 259   static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
 260
 261   g_return_if_fail (mutex);
 262
 263   *mutex = init_mutex;
 264 }
 265
 266 void
 267 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
 268 {
 269   GSystemThread self;
 270
 271   g_return_if_fail (mutex);
 272
 273   if (!g_thread_supported ())
 274     return;
 275
 276   G_THREAD_UF (thread_self, (&self));
 277
 278   if (g_system_thread_equal (self, mutex->owner))
 279     {
 280       mutex->depth++;
 281       return;
 282     }
 283   g_static_mutex_lock (&mutex->mutex);
 284   g_system_thread_assign (mutex->owner, self);
 285   mutex->depth = 1;
 286 }
 287
 288 gboolean
 289 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
 290 {
 291   GSystemThread self;
 292
 293   g_return_val_if_fail (mutex, FALSE);
 294
 295   if (!g_thread_supported ())
 296     return TRUE;
 297
 298   G_THREAD_UF (thread_self, (&self));
 299
 300   if (g_system_thread_equal (self, mutex->owner))
 301     {
 302       mutex->depth++;
 303       return TRUE;
 304     }
 305
 306   if (!g_static_mutex_trylock (&mutex->mutex))
 307     return FALSE;
 308
 309   g_system_thread_assign (mutex->owner, self);
 310   mutex->depth = 1;
 311   return TRUE;
 312 }
 313
 314 void
 315 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
 316 {
 317   g_return_if_fail (mutex);
 318
 319   if (!g_thread_supported ())
 320     return;
 321
 322   if (mutex->depth > 1)
 323     {
 324       mutex->depth--;
 325       return;
 326     }
 327   g_system_thread_assign (mutex->owner, zero_thread);
 328   g_static_mutex_unlock (&mutex->mutex);
 329 }
 330
 331 void
 332 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 333                                 guint            depth)
 334 {
 335   GSystemThread self;
 336   g_return_if_fail (mutex);
 337
 338   if (!g_thread_supported ())
 339     return;
 340
 341   if (depth == 0)
 342     return;
 343
 344   G_THREAD_UF (thread_self, (&self));
 345
 346   if (g_system_thread_equal (self, mutex->owner))
 347     {
 348       mutex->depth += depth;
 349       return;
 350     }
 351   g_static_mutex_lock (&mutex->mutex);
 352   g_system_thread_assign (mutex->owner, self);
 353   mutex->depth = depth;
 354 }
 355
 356 guint
 357 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
 358 {
 359   guint depth;
 360
 361   g_return_val_if_fail (mutex, 0);
 362
 363   if (!g_thread_supported ())
 364     return 1;
 365
 366   depth = mutex->depth;
 367
 368   g_system_thread_assign (mutex->owner, zero_thread);
 369   mutex->depth = 0;
 370   g_static_mutex_unlock (&mutex->mutex);
 371
 372   return depth;
 373 }
 374
 375 void
 376 g_static_rec_mutex_free (GStaticRecMutex *mutex)
 377 {
 378   g_return_if_fail (mutex);
 379
 380   g_static_mutex_free (&mutex->mutex);
 381 }
 382
 383 void
 384 g_static_private_init (GStaticPrivate *private_key)
 385 {
 386   private_key->index = 0;
 387 }
 388
 389 gpointer
 390 g_static_private_get (GStaticPrivate *private_key)
 391 {
 392   GRealThread *self = (GRealThread*) g_thread_self ();
 393   GArray *array;
 394
 395   array = self->private_data;
 396   if (!array)
 397     return NULL;
 398
 399   if (!private_key->index)
 400     return NULL;
 401   else if (private_key->index <= array->len)
 402     return g_array_index (array, GStaticPrivateNode,
 403                           private_key->index - 1).data;
 404   else
 405     return NULL;
 406 }
 407
 408 void
 409 g_static_private_set (GStaticPrivate *private_key,
 410                       gpointer        data,
 411                       GDestroyNotify  notify)
 412 {
 413   GRealThread *self = (GRealThread*) g_thread_self ();
 414   GArray *array;
 415   static guint next_index = 0;
 416   GStaticPrivateNode *node;
 417
 418   array = self->private_data;
 419   if (!array)
 420     {
 421       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
 422       self->private_data = array;
 423     }
 424
 425   if (!private_key->index)
 426     {
 427       G_LOCK (g_thread);
 428
 429       if (!private_key->index)
 430         {
 431           if (g_thread_free_indeces)
 432             {
 433               private_key->index =
 434                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
 435               g_thread_free_indeces =
 436                 g_slist_delete_link (g_thread_free_indeces,
 437                                      g_thread_free_indeces);
 438             }
 439           else
 440             private_key->index = ++next_index;
 441         }
 442
 443       G_UNLOCK (g_thread);
 444     }
 445
 446   if (private_key->index > array->len)
 447     g_array_set_size (array, private_key->index);
 448
 449   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
 450   if (node->destroy)
 451     {
 452       gpointer ddata = node->data;
 453       GDestroyNotify ddestroy = node->destroy;
 454
 455       node->data = data;
 456       node->destroy = notify;
 457
 458       ddestroy (ddata);
 459     }
 460   else
 461     {
 462       node->data = data;
 463       node->destroy = notify;
 464     }
 465 }
 466
 467 void
 468 g_static_private_free (GStaticPrivate *private_key)
 469 {
 470   guint index = private_key->index;
 471   GRealThread *thread;
 472
 473   if (!index)
 474     return;
 475
 476   private_key->index = 0;
 477
 478   G_LOCK (g_thread);
 479
 480   thread = g_thread_all_threads;
 481   while (thread)
 482     {
 483       GArray *array = thread->private_data;
 484       thread = thread->next;
 485
 486       if (array && index <= array->len)
 487         {
 488           GStaticPrivateNode *node = &g_array_index (array,
 489                                                      GStaticPrivateNode,
 490                                                      index - 1);
 491           gpointer ddata = node->data;
 492           GDestroyNotify ddestroy = node->destroy;
 493
 494           node->data = NULL;
 495           node->destroy = NULL;
 496
 497           if (ddestroy)
 498             {
 499               G_UNLOCK (g_thread);
 500               ddestroy (ddata);
 501               G_LOCK (g_thread);
 502               }
 503         }
 504     }
 505   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
 506                                            GUINT_TO_POINTER (index));
 507   G_UNLOCK (g_thread);
 508 }
 509
 510 static void
 511 g_thread_cleanup (gpointer data)
 512 {
 513   if (data)
 514     {
 515       GRealThread* thread = data;
 516       if (thread->private_data)
 517         {
 518           GArray* array = thread->private_data;
 519           guint i;
 520
 521           for (i = 0; i < array->len; i++ )
 522             {
 523               GStaticPrivateNode *node =
 524                 &g_array_index (array, GStaticPrivateNode, i);
 525               if (node->destroy)
 526                 node->destroy (node->data);
 527             }
 528           g_array_free (array, TRUE);
 529         }
 530
 531       /* We only free the thread structure, if it isn't joinable. If
 532          it is, the structure is freed in g_thread_join */
 533       if (!thread->thread.joinable)
 534         {
 535           GRealThread *t, *p;
 536
 537           G_LOCK (g_thread);
 538           for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 539             {
 540               if (t == thread)
 541                 {
 542                   if (p)
 543                     p->next = t->next;
 544                   else
 545                     g_thread_all_threads = t->next;
 546                   break;
 547                 }
 548             }
 549           G_UNLOCK (g_thread);
 550
 551           /* Just to make sure, this isn't used any more */
 552           g_system_thread_assign (thread->system_thread, zero_thread);
 553           g_free (thread);
 554         }
 555     }
 556 }
 557
 558 static void
 559 g_thread_fail (void)
 560 {
 561   g_error ("The thread system is not yet initialized.");
 562 }
 563
 564 static gpointer
 565 g_thread_create_proxy (gpointer data)
 566 {
 567   GRealThread* thread = data;
 568
 569   g_assert (data);
 570
 571   /* This has to happen before G_LOCK, as that might call g_thread_self */
 572   g_private_set (g_thread_specific_private, data);
 573
 574   /* the lock makes sure, that thread->system_thread is written,
 575      before thread->thread.func is called. See g_thread_create. */
 576   G_LOCK (g_thread);
 577   G_UNLOCK (g_thread);
 578
 579   thread->retval = thread->thread.func (thread->thread.data);
 580
 581   return NULL;
 582 }
 583
 584 GThread*
 585 g_thread_create_full (GThreadFunc                func,
 586                       gpointer           data,
 587                       gulong             stack_size,
 588                       gboolean           joinable,
 589                       gboolean           bound,
 590                       GThreadPriority    priority,
 591                       GError                **error)
 592 {
 593   GRealThread* result;
 594   GError *local_error = NULL;
 595   g_return_val_if_fail (func, NULL);
 596   g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
 597   g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
 598
 599   result = g_new0 (GRealThread, 1);
 600
 601   result->thread.joinable = joinable;
 602   result->thread.priority = priority;
 603   result->thread.func = func;
 604   result->thread.data = data;
 605   result->private_data = NULL;
 606   G_LOCK (g_thread);
 607   G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
 608                                stack_size, joinable, bound, priority,
 609                                &result->system_thread, &local_error));
 610   result->next = g_thread_all_threads;
 611   g_thread_all_threads = result;
 612   G_UNLOCK (g_thread);
 613
 614   if (local_error)
 615     {
 616       g_propagate_error (error, local_error);
 617       g_free (result);
 618       return NULL;
 619     }
 620
 621   return (GThread*) result;
 622 }
 623
 624 void
 625 g_thread_exit (gpointer retval)
 626 {
 627   GRealThread* real = (GRealThread*) g_thread_self ();
 628   real->retval = retval;
 629   G_THREAD_CF (thread_exit, (void)0, ());
 630 }
 631
 632 gpointer
 633 g_thread_join (GThread* thread)
 634 {
 635   GRealThread* real = (GRealThread*) thread;
 636   GRealThread *p, *t;
 637   gpointer retval;
 638
 639   g_return_val_if_fail (thread, NULL);
 640   g_return_val_if_fail (thread->joinable, NULL);
 641   g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
 642                                                 zero_thread), NULL);
 643
 644   G_THREAD_UF (thread_join, (&real->system_thread));
 645
 646   retval = real->retval;
 647
 648   G_LOCK (g_thread);
 649   for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 650     {
 651       if (t == (GRealThread*) thread)
 652         {
 653           if (p)
 654             p->next = t->next;
 655           else
 656             g_thread_all_threads = t->next;
 657           break;
 658         }
 659     }
 660   G_UNLOCK (g_thread);
 661
 662   /* Just to make sure, this isn't used any more */
 663   thread->joinable = 0;
 664   g_system_thread_assign (real->system_thread, zero_thread);
 665
 666   /* the thread structure for non-joinable threads is freed upon
 667      thread end. We free the memory here. This will leave a loose end,
 668      if a joinable thread is not joined. */
 669
 670   g_free (thread);
 671
 672   return retval;
 673 }
 674
 675 void
 676 g_thread_set_priority (GThread* thread,
 677                        GThreadPriority priority)
 678 {
 679   GRealThread* real = (GRealThread*) thread;
 680
 681   g_return_if_fail (thread);
 682   g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
 683   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 684   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 685
 686   thread->priority = priority;
 687
 688   G_THREAD_CF (thread_set_priority, (void)0,
 689                (&real->system_thread, priority));
 690 }
 691
 692 GThread*
 693 g_thread_self (void)
 694 {
 695   GRealThread* thread = g_private_get (g_thread_specific_private);
 696
 697   if (!thread)
 698     {
 699       /* If no thread data is available, provide and set one.  This
 700          can happen for the main thread and for threads, that are not
 701          created by GLib. */
 702       thread = g_new0 (GRealThread, 1);
 703       thread->thread.joinable = FALSE; /* This is a save guess */
 704       thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
 705                                                              just a guess */
 706       thread->thread.func = NULL;
 707       thread->thread.data = NULL;
 708       thread->private_data = NULL;
 709
 710       if (g_thread_supported ())
 711         G_THREAD_UF (thread_self, (&thread->system_thread));
 712
 713       g_private_set (g_thread_specific_private, thread);
 714
 715       G_LOCK (g_thread);
 716       thread->next = g_thread_all_threads;
 717       g_thread_all_threads = thread;
 718       G_UNLOCK (g_thread);
 719     }
 720
 721   return (GThread*)thread;
 722 }
 723
 724 void
 725 g_static_rw_lock_init (GStaticRWLock* lock)
 726 {
 727   static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
 728
 729   g_return_if_fail (lock);
 730
 731   *lock = init_lock;
 732 }
 733
 734 inline static void
 735 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
 736 {
 737   if (!*cond)
 738       *cond = g_cond_new ();
 739   g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
 740 }
 741
 742 inline static void
 743 g_static_rw_lock_signal (GStaticRWLock* lock)
 744 {
 745   if (lock->want_to_write && lock->write_cond)
 746     g_cond_signal (lock->write_cond);
 747   else if (lock->want_to_read && lock->read_cond)
 748     g_cond_broadcast (lock->read_cond);
 749 }
 750
 751 void
 752 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
 753 {
 754   g_return_if_fail (lock);
 755
 756   if (!g_threads_got_initialized)
 757     return;
 758
 759   g_static_mutex_lock (&lock->mutex);
 760   lock->want_to_read++;
 761   while (lock->have_writer || lock->want_to_write)
 762     g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
 763   lock->want_to_read--;
 764   lock->read_counter++;
 765   g_static_mutex_unlock (&lock->mutex);
 766 }
 767
 768 gboolean
 769 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
 770 {
 771   gboolean ret_val = FALSE;
 772
 773   g_return_val_if_fail (lock, FALSE);
 774
 775   if (!g_threads_got_initialized)
 776     return TRUE;
 777
 778   g_static_mutex_lock (&lock->mutex);
 779   if (!lock->have_writer && !lock->want_to_write)
 780     {
 781       lock->read_counter++;
 782       ret_val = TRUE;
 783     }
 784   g_static_mutex_unlock (&lock->mutex);
 785   return ret_val;
 786 }
 787
 788 void
 789 g_static_rw_lock_reader_unlock  (GStaticRWLock* lock)
 790 {
 791   g_return_if_fail (lock);
 792
 793   if (!g_threads_got_initialized)
 794     return;
 795
 796   g_static_mutex_lock (&lock->mutex);
 797   lock->read_counter--;
 798   if (lock->read_counter == 0)
 799     g_static_rw_lock_signal (lock);
 800   g_static_mutex_unlock (&lock->mutex);
 801 }
 802
 803 void
 804 g_static_rw_lock_writer_lock (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->want_to_write++;
 813   while (lock->have_writer || lock->read_counter)
 814     g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
 815   lock->want_to_write--;
 816   lock->have_writer = TRUE;
 817   g_static_mutex_unlock (&lock->mutex);
 818 }
 819
 820 gboolean
 821 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
 822 {
 823   gboolean ret_val = FALSE;
 824
 825   g_return_val_if_fail (lock, FALSE);
 826
 827   if (!g_threads_got_initialized)
 828     return TRUE;
 829
 830   g_static_mutex_lock (&lock->mutex);
 831   if (!lock->have_writer && !lock->read_counter)
 832     {
 833       lock->have_writer = TRUE;
 834       ret_val = TRUE;
 835     }
 836   g_static_mutex_unlock (&lock->mutex);
 837   return ret_val;
 838 }
 839
 840 void
 841 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
 842 {
 843   g_return_if_fail (lock);
 844
 845   if (!g_threads_got_initialized)
 846     return;
 847
 848   g_static_mutex_lock (&lock->mutex);
 849   lock->have_writer = FALSE;
 850   g_static_rw_lock_signal (lock);
 851   g_static_mutex_unlock (&lock->mutex);
 852 }
 853
 854 void
 855 g_static_rw_lock_free (GStaticRWLock* lock)
 856 {
 857   g_return_if_fail (lock);
 858
 859   if (lock->read_cond)
 860     {
 861       g_cond_free (lock->read_cond);
 862       lock->read_cond = NULL;
 863     }
 864   if (lock->write_cond)
 865     {
 866       g_cond_free (lock->write_cond);
 867       lock->write_cond = NULL;
 868     }
 869   g_static_mutex_free (&lock->mutex);
 870 }
 871
 872 /**
 873  * g_thread_foreach
 874  * @thread_func: function to call for all GThread structures
 875  * @user_data:   second argument to @thread_func
 876  *
 877  * Call @thread_func on all existing #GThread structures. Note that
 878  * threads may decide to exit while @thread_func is running, so
 879  * without intimate knowledge about the lifetime of foreign threads,
 880  * @thread_func shouldn't access the GThread* pointer passed in as
 881  * first argument. However, @thread_func will not be called for threads
 882  * which are known to have exited already.
 883  *
 884  * Due to thread lifetime checks, this function has an execution complexity
 885  * which is quadratic in the number of existing threads.
 886  *
 887  * Since: 2.10
 888  */
 889 void
 890 g_thread_foreach (GFunc    thread_func,
 891                   gpointer user_data)
 892 {
 893   GSList *slist = NULL;
 894   GRealThread *thread;
 895   g_return_if_fail (thread_func != NULL);
 896   /* snapshot the list of threads for iteration */
 897   G_LOCK (g_thread);
 898   for (thread = g_thread_all_threads; thread; thread = thread->next)
 899     slist = g_slist_prepend (slist, thread);
 900   G_UNLOCK (g_thread);
 901   /* walk the list, skipping non-existant threads */
 902   while (slist)
 903     {
 904       GSList *node = slist;
 905       slist = node->next;
 906       /* check whether the current thread still exists */
 907       G_LOCK (g_thread);
 908       for (thread = g_thread_all_threads; thread; thread = thread->next)
 909         if (thread == node->data)
 910           break;
 911       G_UNLOCK (g_thread);
 912       if (thread)
 913         thread_func (thread, user_data);
 914       g_slist_free_1 (node);
 915     }
 916 }
 917
 918 #define __G_THREAD_C__
 919 #include "galiasdef.c"