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 #ifndef G_OS_WIN32
  42 #include <sys/time.h>
  43 #include <time.h>
  44 #endif /* G_OS_WIN32 */
  45
  46 #include <string.h>
  47
  48 #include "glib.h"
  49 #include "gthreadprivate.h"
  50 #include "galias.h"
  51
  52 GQuark
  53 g_thread_error_quark (void)
  54 {
  55   return g_quark_from_static_string ("g_thread_error");
  56 }
  57
  58 /* Keep this in sync with GRealThread in gmain.c! */
  59 typedef struct _GRealThread GRealThread;
  60 struct  _GRealThread
  61 {
  62   GThread thread;
  63   gpointer private_data;
  64   GRealThread *next;
  65   gpointer retval;
  66   GSystemThread system_thread;
  67 };
  68
  69 typedef struct _GStaticPrivateNode GStaticPrivateNode;
  70 struct _GStaticPrivateNode
  71 {
  72   gpointer       data;
  73   GDestroyNotify destroy;
  74 };
  75
  76 static void    g_thread_cleanup (gpointer data);
  77 static void    g_thread_fail (void);
  78 static guint64 gettime (void);
  79
  80 /* Global variables */
  81
  82 static GSystemThread zero_thread; /* This is initialized to all zero */
  83 gboolean g_thread_use_default_impl = TRUE;
  84 gboolean g_threads_got_initialized = FALSE;
  85
  86 GThreadFunctions g_thread_functions_for_glib_use = {
  87   (GMutex*(*)())g_thread_fail,                 /* mutex_new */
  88   NULL,                                        /* mutex_lock */
  89   NULL,                                        /* mutex_trylock */
  90   NULL,                                        /* mutex_unlock */
  91   NULL,                                        /* mutex_free */
  92   (GCond*(*)())g_thread_fail,                  /* cond_new */
  93   NULL,                                        /* cond_signal */
  94   NULL,                                        /* cond_broadcast */
  95   NULL,                                        /* cond_wait */
  96   NULL,                                        /* cond_timed_wait  */
  97   NULL,                                        /* cond_free */
  98   (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
  99   NULL,                                        /* private_get */
 100   NULL,                                        /* private_set */
 101   (void(*)(GThreadFunc, gpointer, gulong,
 102            gboolean, gboolean, GThreadPriority,
 103            gpointer, GError**))g_thread_fail,  /* thread_create */
 104   NULL,                                        /* thread_yield */
 105   NULL,                                        /* thread_join */
 106   NULL,                                        /* thread_exit */
 107   NULL,                                        /* thread_set_priority */
 108   NULL,                                         /* thread_self */
 109   NULL,                                         /* thread_equal */
 110   gettime                                      /* gettime */
 111 };
 112
 113 /* Local data */
 114
 115 static GMutex   *g_once_mutex = NULL;
 116 static GCond    *g_once_cond = NULL;
 117 static GPrivate *g_thread_specific_private = NULL;
 118 static GRealThread *g_thread_all_threads = NULL;
 119 static GSList   *g_thread_free_indeces = NULL;
 120
 121 G_LOCK_DEFINE_STATIC (g_thread);
 122
 123 #ifdef G_THREADS_ENABLED
 124 /* This must be called only once, before any threads are created.
 125  * It will only be called from g_thread_init() in -lgthread.
 126  */
 127 void
 128 g_thread_init_glib (void)
 129 {
 130   /* We let the main thread (the one that calls g_thread_init) inherit
 131    * the static_private data set before calling g_thread_init
 132    */
 133   GRealThread* main_thread = (GRealThread*) g_thread_self ();
 134
 135   /* mutex and cond creation works without g_threads_got_initialized */
 136   g_once_mutex = g_mutex_new ();
 137   g_once_cond = g_cond_new ();
 138
 139   /* we may only create mutex and cond in here */
 140   _g_mem_thread_init_noprivate_nomessage ();
 141
 142   /* setup the basic threading system */
 143   g_threads_got_initialized = TRUE;
 144   g_thread_specific_private = g_private_new (g_thread_cleanup);
 145   g_private_set (g_thread_specific_private, main_thread);
 146   G_THREAD_UF (thread_self, (&main_thread->system_thread));
 147
 148   /* complete memory system initialization, g_private_*() works now */
 149   _g_slice_thread_init_nomessage ();
 150
 151   /* accomplish log system initialization to enable messaging */
 152   _g_messages_thread_init_nomessage ();
 153
 154   /* we may run full-fledged initializers from here */
 155   _g_atomic_thread_init ();
 156   _g_convert_thread_init ();
 157   _g_rand_thread_init ();
 158   _g_main_thread_init ();
 159   _g_utils_thread_init ();
 160 #ifdef G_OS_WIN32
 161   _g_win32_thread_init ();
 162 #endif
 163 }
 164 #endif /* G_THREADS_ENABLED */
 165
 166 gpointer
 167 g_once_impl (GOnce       *once,
 168              GThreadFunc  func,
 169              gpointer     arg)
 170 {
 171   g_mutex_lock (g_once_mutex);
 172
 173   while (once->status == G_ONCE_STATUS_PROGRESS)
 174     g_cond_wait (g_once_cond, g_once_mutex);
 175
 176   if (once->status != G_ONCE_STATUS_READY)
 177     {
 178       once->status = G_ONCE_STATUS_PROGRESS;
 179       g_mutex_unlock (g_once_mutex);
 180
 181       once->retval = func (arg);
 182
 183       g_mutex_lock (g_once_mutex);
 184       once->status = G_ONCE_STATUS_READY;
 185       g_cond_broadcast (g_once_cond);
 186     }
 187
 188   g_mutex_unlock (g_once_mutex);
 189
 190   return once->retval;
 191 }
 192
 193 void
 194 g_static_mutex_init (GStaticMutex *mutex)
 195 {
 196   static const GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
 197
 198   g_return_if_fail (mutex);
 199
 200   *mutex = init_mutex;
 201 }
 202
 203 GMutex *
 204 g_static_mutex_get_mutex_impl (GMutex** mutex)
 205 {
 206   if (!g_thread_supported ())
 207     return NULL;
 208
 209   g_assert (g_once_mutex);
 210
 211   g_mutex_lock (g_once_mutex);
 212
 213   if (!(*mutex))
 214     g_atomic_pointer_set (mutex, g_mutex_new());
 215
 216   g_mutex_unlock (g_once_mutex);
 217
 218   return *mutex;
 219 }
 220
 221 void
 222 g_static_mutex_free (GStaticMutex* mutex)
 223 {
 224   GMutex **runtime_mutex;
 225
 226   g_return_if_fail (mutex);
 227
 228   /* The runtime_mutex is the first (or only) member of GStaticMutex,
 229    * see both versions (of glibconfig.h) in configure.in */
 230   runtime_mutex = ((GMutex**)mutex);
 231
 232   if (*runtime_mutex)
 233     g_mutex_free (*runtime_mutex);
 234
 235   *runtime_mutex = NULL;
 236 }
 237
 238 void
 239 g_static_rec_mutex_init (GStaticRecMutex *mutex)
 240 {
 241   static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
 242
 243   g_return_if_fail (mutex);
 244
 245   *mutex = init_mutex;
 246 }
 247
 248 void
 249 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
 250 {
 251   GSystemThread self;
 252
 253   g_return_if_fail (mutex);
 254
 255   if (!g_thread_supported ())
 256     return;
 257
 258   G_THREAD_UF (thread_self, (&self));
 259
 260   if (g_system_thread_equal (self, mutex->owner))
 261     {
 262       mutex->depth++;
 263       return;
 264     }
 265   g_static_mutex_lock (&mutex->mutex);
 266   g_system_thread_assign (mutex->owner, self);
 267   mutex->depth = 1;
 268 }
 269
 270 gboolean
 271 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
 272 {
 273   GSystemThread self;
 274
 275   g_return_val_if_fail (mutex, FALSE);
 276
 277   if (!g_thread_supported ())
 278     return TRUE;
 279
 280   G_THREAD_UF (thread_self, (&self));
 281
 282   if (g_system_thread_equal (self, mutex->owner))
 283     {
 284       mutex->depth++;
 285       return TRUE;
 286     }
 287
 288   if (!g_static_mutex_trylock (&mutex->mutex))
 289     return FALSE;
 290
 291   g_system_thread_assign (mutex->owner, self);
 292   mutex->depth = 1;
 293   return TRUE;
 294 }
 295
 296 void
 297 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
 298 {
 299   g_return_if_fail (mutex);
 300
 301   if (!g_thread_supported ())
 302     return;
 303
 304   if (mutex->depth > 1)
 305     {
 306       mutex->depth--;
 307       return;
 308     }
 309   g_system_thread_assign (mutex->owner, zero_thread);
 310   g_static_mutex_unlock (&mutex->mutex);
 311 }
 312
 313 void
 314 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 315                                 guint            depth)
 316 {
 317   GSystemThread self;
 318   g_return_if_fail (mutex);
 319
 320   if (!g_thread_supported ())
 321     return;
 322
 323   if (depth == 0)
 324     return;
 325
 326   G_THREAD_UF (thread_self, (&self));
 327
 328   if (g_system_thread_equal (self, mutex->owner))
 329     {
 330       mutex->depth += depth;
 331       return;
 332     }
 333   g_static_mutex_lock (&mutex->mutex);
 334   g_system_thread_assign (mutex->owner, self);
 335   mutex->depth = depth;
 336 }
 337
 338 guint
 339 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
 340 {
 341   guint depth;
 342
 343   g_return_val_if_fail (mutex, 0);
 344
 345   if (!g_thread_supported ())
 346     return 1;
 347
 348   depth = mutex->depth;
 349
 350   g_system_thread_assign (mutex->owner, zero_thread);
 351   mutex->depth = 0;
 352   g_static_mutex_unlock (&mutex->mutex);
 353
 354   return depth;
 355 }
 356
 357 void
 358 g_static_rec_mutex_free (GStaticRecMutex *mutex)
 359 {
 360   g_return_if_fail (mutex);
 361
 362   g_static_mutex_free (&mutex->mutex);
 363 }
 364
 365 void
 366 g_static_private_init (GStaticPrivate *private_key)
 367 {
 368   private_key->index = 0;
 369 }
 370
 371 gpointer
 372 g_static_private_get (GStaticPrivate *private_key)
 373 {
 374   GRealThread *self = (GRealThread*) g_thread_self ();
 375   GArray *array;
 376
 377   array = self->private_data;
 378   if (!array)
 379     return NULL;
 380
 381   if (!private_key->index)
 382     return NULL;
 383   else if (private_key->index <= array->len)
 384     return g_array_index (array, GStaticPrivateNode,
 385                           private_key->index - 1).data;
 386   else
 387     return NULL;
 388 }
 389
 390 void
 391 g_static_private_set (GStaticPrivate *private_key,
 392                       gpointer        data,
 393                       GDestroyNotify  notify)
 394 {
 395   GRealThread *self = (GRealThread*) g_thread_self ();
 396   GArray *array;
 397   static guint next_index = 0;
 398   GStaticPrivateNode *node;
 399
 400   array = self->private_data;
 401   if (!array)
 402     {
 403       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
 404       self->private_data = array;
 405     }
 406
 407   if (!private_key->index)
 408     {
 409       G_LOCK (g_thread);
 410
 411       if (!private_key->index)
 412         {
 413           if (g_thread_free_indeces)
 414             {
 415               private_key->index =
 416                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
 417               g_thread_free_indeces =
 418                 g_slist_delete_link (g_thread_free_indeces,
 419                                      g_thread_free_indeces);
 420             }
 421           else
 422             private_key->index = ++next_index;
 423         }
 424
 425       G_UNLOCK (g_thread);
 426     }
 427
 428   if (private_key->index > array->len)
 429     g_array_set_size (array, private_key->index);
 430
 431   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
 432   if (node->destroy)
 433     {
 434       gpointer ddata = node->data;
 435       GDestroyNotify ddestroy = node->destroy;
 436
 437       node->data = data;
 438       node->destroy = notify;
 439
 440       ddestroy (ddata);
 441     }
 442   else
 443     {
 444       node->data = data;
 445       node->destroy = notify;
 446     }
 447 }
 448
 449 void
 450 g_static_private_free (GStaticPrivate *private_key)
 451 {
 452   guint index = private_key->index;
 453   GRealThread *thread;
 454
 455   if (!index)
 456     return;
 457
 458   private_key->index = 0;
 459
 460   G_LOCK (g_thread);
 461
 462   thread = g_thread_all_threads;
 463   while (thread)
 464     {
 465       GArray *array = thread->private_data;
 466       thread = thread->next;
 467
 468       if (array && index <= array->len)
 469         {
 470           GStaticPrivateNode *node = &g_array_index (array,
 471                                                      GStaticPrivateNode,
 472                                                      index - 1);
 473           gpointer ddata = node->data;
 474           GDestroyNotify ddestroy = node->destroy;
 475
 476           node->data = NULL;
 477           node->destroy = NULL;
 478
 479           if (ddestroy)
 480             {
 481               G_UNLOCK (g_thread);
 482               ddestroy (ddata);
 483               G_LOCK (g_thread);
 484               }
 485         }
 486     }
 487   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
 488                                            GUINT_TO_POINTER (index));
 489   G_UNLOCK (g_thread);
 490 }
 491
 492 static void
 493 g_thread_cleanup (gpointer data)
 494 {
 495   if (data)
 496     {
 497       GRealThread* thread = data;
 498       if (thread->private_data)
 499         {
 500           GArray* array = thread->private_data;
 501           guint i;
 502
 503           for (i = 0; i < array->len; i++ )
 504             {
 505               GStaticPrivateNode *node =
 506                 &g_array_index (array, GStaticPrivateNode, i);
 507               if (node->destroy)
 508                 node->destroy (node->data);
 509             }
 510           g_array_free (array, TRUE);
 511         }
 512
 513       /* We only free the thread structure, if it isn't joinable. If
 514          it is, the structure is freed in g_thread_join */
 515       if (!thread->thread.joinable)
 516         {
 517           GRealThread *t, *p;
 518
 519           G_LOCK (g_thread);
 520           for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 521             {
 522               if (t == thread)
 523                 {
 524                   if (p)
 525                     p->next = t->next;
 526                   else
 527                     g_thread_all_threads = t->next;
 528                   break;
 529                 }
 530             }
 531           G_UNLOCK (g_thread);
 532
 533           /* Just to make sure, this isn't used any more */
 534           g_system_thread_assign (thread->system_thread, zero_thread);
 535           g_free (thread);
 536         }
 537     }
 538 }
 539
 540 static void
 541 g_thread_fail (void)
 542 {
 543   g_error ("The thread system is not yet initialized.");
 544 }
 545
 546 static guint64
 547 gettime (void)
 548 {
 549 #ifdef G_OS_WIN32
 550   guint64 v;
 551
 552   GetSystemTimeAsFileTime ((FILETIME *)&v);
 553
 554   return v;
 555 #else
 556   struct timeval tv;
 557
 558   gettimeofday (&tv, NULL);
 559
 560   return (guint64) tv.tv_sec * 1000000000 + tv.tv_usec * 1000;
 561 #endif
 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"