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 */
 234   runtime_mutex = ((GMutex**)mutex);
 235
 236   if (*runtime_mutex)
 237     g_mutex_free (*runtime_mutex);
 238
 239   *runtime_mutex = NULL;
 240 }
 241
 242 void
 243 g_static_rec_mutex_init (GStaticRecMutex *mutex)
 244 {
 245   static const GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
 246
 247   g_return_if_fail (mutex);
 248
 249   *mutex = init_mutex;
 250 }
 251
 252 void
 253 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
 254 {
 255   GSystemThread self;
 256
 257   g_return_if_fail (mutex);
 258
 259   if (!g_thread_supported ())
 260     return;
 261
 262   G_THREAD_UF (thread_self, (&self));
 263
 264   if (g_system_thread_equal (self, mutex->owner))
 265     {
 266       mutex->depth++;
 267       return;
 268     }
 269   g_static_mutex_lock (&mutex->mutex);
 270   g_system_thread_assign (mutex->owner, self);
 271   mutex->depth = 1;
 272 }
 273
 274 gboolean
 275 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
 276 {
 277   GSystemThread self;
 278
 279   g_return_val_if_fail (mutex, FALSE);
 280
 281   if (!g_thread_supported ())
 282     return TRUE;
 283
 284   G_THREAD_UF (thread_self, (&self));
 285
 286   if (g_system_thread_equal (self, mutex->owner))
 287     {
 288       mutex->depth++;
 289       return TRUE;
 290     }
 291
 292   if (!g_static_mutex_trylock (&mutex->mutex))
 293     return FALSE;
 294
 295   g_system_thread_assign (mutex->owner, self);
 296   mutex->depth = 1;
 297   return TRUE;
 298 }
 299
 300 void
 301 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
 302 {
 303   g_return_if_fail (mutex);
 304
 305   if (!g_thread_supported ())
 306     return;
 307
 308   if (mutex->depth > 1)
 309     {
 310       mutex->depth--;
 311       return;
 312     }
 313   g_system_thread_assign (mutex->owner, zero_thread);
 314   g_static_mutex_unlock (&mutex->mutex);
 315 }
 316
 317 void
 318 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 319                                 guint            depth)
 320 {
 321   GSystemThread self;
 322   g_return_if_fail (mutex);
 323
 324   if (!g_thread_supported ())
 325     return;
 326
 327   if (depth == 0)
 328     return;
 329
 330   G_THREAD_UF (thread_self, (&self));
 331
 332   if (g_system_thread_equal (self, mutex->owner))
 333     {
 334       mutex->depth += depth;
 335       return;
 336     }
 337   g_static_mutex_lock (&mutex->mutex);
 338   g_system_thread_assign (mutex->owner, self);
 339   mutex->depth = depth;
 340 }
 341
 342 guint
 343 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
 344 {
 345   guint depth;
 346
 347   g_return_val_if_fail (mutex, 0);
 348
 349   if (!g_thread_supported ())
 350     return 1;
 351
 352   depth = mutex->depth;
 353
 354   g_system_thread_assign (mutex->owner, zero_thread);
 355   mutex->depth = 0;
 356   g_static_mutex_unlock (&mutex->mutex);
 357
 358   return depth;
 359 }
 360
 361 void
 362 g_static_rec_mutex_free (GStaticRecMutex *mutex)
 363 {
 364   g_return_if_fail (mutex);
 365
 366   g_static_mutex_free (&mutex->mutex);
 367 }
 368
 369 void
 370 g_static_private_init (GStaticPrivate *private_key)
 371 {
 372   private_key->index = 0;
 373 }
 374
 375 gpointer
 376 g_static_private_get (GStaticPrivate *private_key)
 377 {
 378   GRealThread *self = (GRealThread*) g_thread_self ();
 379   GArray *array;
 380
 381   array = self->private_data;
 382   if (!array)
 383     return NULL;
 384
 385   if (!private_key->index)
 386     return NULL;
 387   else if (private_key->index <= array->len)
 388     return g_array_index (array, GStaticPrivateNode,
 389                           private_key->index - 1).data;
 390   else
 391     return NULL;
 392 }
 393
 394 void
 395 g_static_private_set (GStaticPrivate *private_key,
 396                       gpointer        data,
 397                       GDestroyNotify  notify)
 398 {
 399   GRealThread *self = (GRealThread*) g_thread_self ();
 400   GArray *array;
 401   static guint next_index = 0;
 402   GStaticPrivateNode *node;
 403
 404   array = self->private_data;
 405   if (!array)
 406     {
 407       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
 408       self->private_data = array;
 409     }
 410
 411   if (!private_key->index)
 412     {
 413       G_LOCK (g_thread);
 414
 415       if (!private_key->index)
 416         {
 417           if (g_thread_free_indeces)
 418             {
 419               private_key->index =
 420                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
 421               g_thread_free_indeces =
 422                 g_slist_delete_link (g_thread_free_indeces,
 423                                      g_thread_free_indeces);
 424             }
 425           else
 426             private_key->index = ++next_index;
 427         }
 428
 429       G_UNLOCK (g_thread);
 430     }
 431
 432   if (private_key->index > array->len)
 433     g_array_set_size (array, private_key->index);
 434
 435   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
 436   if (node->destroy)
 437     {
 438       gpointer ddata = node->data;
 439       GDestroyNotify ddestroy = node->destroy;
 440
 441       node->data = data;
 442       node->destroy = notify;
 443
 444       ddestroy (ddata);
 445     }
 446   else
 447     {
 448       node->data = data;
 449       node->destroy = notify;
 450     }
 451 }
 452
 453 void
 454 g_static_private_free (GStaticPrivate *private_key)
 455 {
 456   guint index = private_key->index;
 457   GRealThread *thread;
 458
 459   if (!index)
 460     return;
 461
 462   private_key->index = 0;
 463
 464   G_LOCK (g_thread);
 465
 466   thread = g_thread_all_threads;
 467   while (thread)
 468     {
 469       GArray *array = thread->private_data;
 470       thread = thread->next;
 471
 472       if (array && index <= array->len)
 473         {
 474           GStaticPrivateNode *node = &g_array_index (array,
 475                                                      GStaticPrivateNode,
 476                                                      index - 1);
 477           gpointer ddata = node->data;
 478           GDestroyNotify ddestroy = node->destroy;
 479
 480           node->data = NULL;
 481           node->destroy = NULL;
 482
 483           if (ddestroy)
 484             {
 485               G_UNLOCK (g_thread);
 486               ddestroy (ddata);
 487               G_LOCK (g_thread);
 488               }
 489         }
 490     }
 491   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
 492                                            GUINT_TO_POINTER (index));
 493   G_UNLOCK (g_thread);
 494 }
 495
 496 static void
 497 g_thread_cleanup (gpointer data)
 498 {
 499   if (data)
 500     {
 501       GRealThread* thread = data;
 502       if (thread->private_data)
 503         {
 504           GArray* array = thread->private_data;
 505           guint i;
 506
 507           for (i = 0; i < array->len; i++ )
 508             {
 509               GStaticPrivateNode *node =
 510                 &g_array_index (array, GStaticPrivateNode, i);
 511               if (node->destroy)
 512                 node->destroy (node->data);
 513             }
 514           g_array_free (array, TRUE);
 515         }
 516
 517       /* We only free the thread structure, if it isn't joinable. If
 518          it is, the structure is freed in g_thread_join */
 519       if (!thread->thread.joinable)
 520         {
 521           GRealThread *t, *p;
 522
 523           G_LOCK (g_thread);
 524           for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 525             {
 526               if (t == thread)
 527                 {
 528                   if (p)
 529                     p->next = t->next;
 530                   else
 531                     g_thread_all_threads = t->next;
 532                   break;
 533                 }
 534             }
 535           G_UNLOCK (g_thread);
 536
 537           /* Just to make sure, this isn't used any more */
 538           g_system_thread_assign (thread->system_thread, zero_thread);
 539           g_free (thread);
 540         }
 541     }
 542 }
 543
 544 static void
 545 g_thread_fail (void)
 546 {
 547   g_error ("The thread system is not yet initialized.");
 548 }
 549
 550 #define G_NSEC_PER_SEC 1000000000
 551
 552 static guint64
 553 gettime (void)
 554 {
 555 #ifdef G_OS_WIN32
 556   guint64 v;
 557
 558   /* Returns 100s of nanoseconds since start of 1601 */
 559   GetSystemTimeAsFileTime ((FILETIME *)&v);
 560
 561   /* Offset to Unix epoch */
 562   v -= G_GINT64_CONSTANT (116444736000000000);
 563   /* Convert to nanoseconds */
 564   v *= 100;
 565
 566   return v;
 567 #else
 568   struct timeval tv;
 569
 570   gettimeofday (&tv, NULL);
 571
 572   return (guint64) tv.tv_sec * G_NSEC_PER_SEC + tv.tv_usec * (G_NSEC_PER_SEC / G_USEC_PER_SEC);
 573 #endif
 574 }
 575
 576 static gpointer
 577 g_thread_create_proxy (gpointer data)
 578 {
 579   GRealThread* thread = data;
 580
 581   g_assert (data);
 582
 583   /* This has to happen before G_LOCK, as that might call g_thread_self */
 584   g_private_set (g_thread_specific_private, data);
 585
 586   /* the lock makes sure, that thread->system_thread is written,
 587      before thread->thread.func is called. See g_thread_create. */
 588   G_LOCK (g_thread);
 589   G_UNLOCK (g_thread);
 590
 591   thread->retval = thread->thread.func (thread->thread.data);
 592
 593   return NULL;
 594 }
 595
 596 GThread*
 597 g_thread_create_full (GThreadFunc                func,
 598                       gpointer           data,
 599                       gulong             stack_size,
 600                       gboolean           joinable,
 601                       gboolean           bound,
 602                       GThreadPriority    priority,
 603                       GError                **error)
 604 {
 605   GRealThread* result;
 606   GError *local_error = NULL;
 607   g_return_val_if_fail (func, NULL);
 608   g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
 609   g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
 610
 611   result = g_new0 (GRealThread, 1);
 612
 613   result->thread.joinable = joinable;
 614   result->thread.priority = priority;
 615   result->thread.func = func;
 616   result->thread.data = data;
 617   result->private_data = NULL;
 618   G_LOCK (g_thread);
 619   G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
 620                                stack_size, joinable, bound, priority,
 621                                &result->system_thread, &local_error));
 622   result->next = g_thread_all_threads;
 623   g_thread_all_threads = result;
 624   G_UNLOCK (g_thread);
 625
 626   if (local_error)
 627     {
 628       g_propagate_error (error, local_error);
 629       g_free (result);
 630       return NULL;
 631     }
 632
 633   return (GThread*) result;
 634 }
 635
 636 void
 637 g_thread_exit (gpointer retval)
 638 {
 639   GRealThread* real = (GRealThread*) g_thread_self ();
 640   real->retval = retval;
 641   G_THREAD_CF (thread_exit, (void)0, ());
 642 }
 643
 644 gpointer
 645 g_thread_join (GThread* thread)
 646 {
 647   GRealThread* real = (GRealThread*) thread;
 648   GRealThread *p, *t;
 649   gpointer retval;
 650
 651   g_return_val_if_fail (thread, NULL);
 652   g_return_val_if_fail (thread->joinable, NULL);
 653   g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
 654                                                 zero_thread), NULL);
 655
 656   G_THREAD_UF (thread_join, (&real->system_thread));
 657
 658   retval = real->retval;
 659
 660   G_LOCK (g_thread);
 661   for (t = g_thread_all_threads, p = NULL; t; p = t, t = t->next)
 662     {
 663       if (t == (GRealThread*) thread)
 664         {
 665           if (p)
 666             p->next = t->next;
 667           else
 668             g_thread_all_threads = t->next;
 669           break;
 670         }
 671     }
 672   G_UNLOCK (g_thread);
 673
 674   /* Just to make sure, this isn't used any more */
 675   thread->joinable = 0;
 676   g_system_thread_assign (real->system_thread, zero_thread);
 677
 678   /* the thread structure for non-joinable threads is freed upon
 679      thread end. We free the memory here. This will leave a loose end,
 680      if a joinable thread is not joined. */
 681
 682   g_free (thread);
 683
 684   return retval;
 685 }
 686
 687 void
 688 g_thread_set_priority (GThread* thread,
 689                        GThreadPriority priority)
 690 {
 691   GRealThread* real = (GRealThread*) thread;
 692
 693   g_return_if_fail (thread);
 694   g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
 695   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 696   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 697
 698   thread->priority = priority;
 699
 700   G_THREAD_CF (thread_set_priority, (void)0,
 701                (&real->system_thread, priority));
 702 }
 703
 704 GThread*
 705 g_thread_self (void)
 706 {
 707   GRealThread* thread = g_private_get (g_thread_specific_private);
 708
 709   if (!thread)
 710     {
 711       /* If no thread data is available, provide and set one.  This
 712          can happen for the main thread and for threads, that are not
 713          created by GLib. */
 714       thread = g_new0 (GRealThread, 1);
 715       thread->thread.joinable = FALSE; /* This is a save guess */
 716       thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
 717                                                              just a guess */
 718       thread->thread.func = NULL;
 719       thread->thread.data = NULL;
 720       thread->private_data = NULL;
 721
 722       if (g_thread_supported ())
 723         G_THREAD_UF (thread_self, (&thread->system_thread));
 724
 725       g_private_set (g_thread_specific_private, thread);
 726
 727       G_LOCK (g_thread);
 728       thread->next = g_thread_all_threads;
 729       g_thread_all_threads = thread;
 730       G_UNLOCK (g_thread);
 731     }
 732
 733   return (GThread*)thread;
 734 }
 735
 736 void
 737 g_static_rw_lock_init (GStaticRWLock* lock)
 738 {
 739   static const GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
 740
 741   g_return_if_fail (lock);
 742
 743   *lock = init_lock;
 744 }
 745
 746 inline static void
 747 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
 748 {
 749   if (!*cond)
 750       *cond = g_cond_new ();
 751   g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
 752 }
 753
 754 inline static void
 755 g_static_rw_lock_signal (GStaticRWLock* lock)
 756 {
 757   if (lock->want_to_write && lock->write_cond)
 758     g_cond_signal (lock->write_cond);
 759   else if (lock->want_to_read && lock->read_cond)
 760     g_cond_broadcast (lock->read_cond);
 761 }
 762
 763 void
 764 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
 765 {
 766   g_return_if_fail (lock);
 767
 768   if (!g_threads_got_initialized)
 769     return;
 770
 771   g_static_mutex_lock (&lock->mutex);
 772   lock->want_to_read++;
 773   while (lock->have_writer || lock->want_to_write)
 774     g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
 775   lock->want_to_read--;
 776   lock->read_counter++;
 777   g_static_mutex_unlock (&lock->mutex);
 778 }
 779
 780 gboolean
 781 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
 782 {
 783   gboolean ret_val = FALSE;
 784
 785   g_return_val_if_fail (lock, FALSE);
 786
 787   if (!g_threads_got_initialized)
 788     return TRUE;
 789
 790   g_static_mutex_lock (&lock->mutex);
 791   if (!lock->have_writer && !lock->want_to_write)
 792     {
 793       lock->read_counter++;
 794       ret_val = TRUE;
 795     }
 796   g_static_mutex_unlock (&lock->mutex);
 797   return ret_val;
 798 }
 799
 800 void
 801 g_static_rw_lock_reader_unlock  (GStaticRWLock* lock)
 802 {
 803   g_return_if_fail (lock);
 804
 805   if (!g_threads_got_initialized)
 806     return;
 807
 808   g_static_mutex_lock (&lock->mutex);
 809   lock->read_counter--;
 810   if (lock->read_counter == 0)
 811     g_static_rw_lock_signal (lock);
 812   g_static_mutex_unlock (&lock->mutex);
 813 }
 814
 815 void
 816 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
 817 {
 818   g_return_if_fail (lock);
 819
 820   if (!g_threads_got_initialized)
 821     return;
 822
 823   g_static_mutex_lock (&lock->mutex);
 824   lock->want_to_write++;
 825   while (lock->have_writer || lock->read_counter)
 826     g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
 827   lock->want_to_write--;
 828   lock->have_writer = TRUE;
 829   g_static_mutex_unlock (&lock->mutex);
 830 }
 831
 832 gboolean
 833 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
 834 {
 835   gboolean ret_val = FALSE;
 836
 837   g_return_val_if_fail (lock, FALSE);
 838
 839   if (!g_threads_got_initialized)
 840     return TRUE;
 841
 842   g_static_mutex_lock (&lock->mutex);
 843   if (!lock->have_writer && !lock->read_counter)
 844     {
 845       lock->have_writer = TRUE;
 846       ret_val = TRUE;
 847     }
 848   g_static_mutex_unlock (&lock->mutex);
 849   return ret_val;
 850 }
 851
 852 void
 853 g_static_rw_lock_writer_unlock (GStaticRWLock* lock)
 854 {
 855   g_return_if_fail (lock);
 856
 857   if (!g_threads_got_initialized)
 858     return;
 859
 860   g_static_mutex_lock (&lock->mutex);
 861   lock->have_writer = FALSE;
 862   g_static_rw_lock_signal (lock);
 863   g_static_mutex_unlock (&lock->mutex);
 864 }
 865
 866 void
 867 g_static_rw_lock_free (GStaticRWLock* lock)
 868 {
 869   g_return_if_fail (lock);
 870
 871   if (lock->read_cond)
 872     {
 873       g_cond_free (lock->read_cond);
 874       lock->read_cond = NULL;
 875     }
 876   if (lock->write_cond)
 877     {
 878       g_cond_free (lock->write_cond);
 879       lock->write_cond = NULL;
 880     }
 881   g_static_mutex_free (&lock->mutex);
 882 }
 883
 884 /**
 885  * g_thread_foreach
 886  * @thread_func: function to call for all GThread structures
 887  * @user_data:   second argument to @thread_func
 888  *
 889  * Call @thread_func on all existing #GThread structures. Note that
 890  * threads may decide to exit while @thread_func is running, so
 891  * without intimate knowledge about the lifetime of foreign threads,
 892  * @thread_func shouldn't access the GThread* pointer passed in as
 893  * first argument. However, @thread_func will not be called for threads
 894  * which are known to have exited already.
 895  *
 896  * Due to thread lifetime checks, this function has an execution complexity
 897  * which is quadratic in the number of existing threads.
 898  *
 899  * Since: 2.10
 900  */
 901 void
 902 g_thread_foreach (GFunc    thread_func,
 903                   gpointer user_data)
 904 {
 905   GSList *slist = NULL;
 906   GRealThread *thread;
 907   g_return_if_fail (thread_func != NULL);
 908   /* snapshot the list of threads for iteration */
 909   G_LOCK (g_thread);
 910   for (thread = g_thread_all_threads; thread; thread = thread->next)
 911     slist = g_slist_prepend (slist, thread);
 912   G_UNLOCK (g_thread);
 913   /* walk the list, skipping non-existant threads */
 914   while (slist)
 915     {
 916       GSList *node = slist;
 917       slist = node->next;
 918       /* check whether the current thread still exists */
 919       G_LOCK (g_thread);
 920       for (thread = g_thread_all_threads; thread; thread = thread->next)
 921         if (thread == node->data)
 922           break;
 923       G_UNLOCK (g_thread);
 924       if (thread)
 925         thread_func (thread, user_data);
 926       g_slist_free_1 (node);
 927     }
 928 }
 929
 930 #define __G_THREAD_C__
 931 #include "galiasdef.c"