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  * gmutex.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 G_THREAD_USE_PID_SURROGATE
  38 #include <sys/types.h>
  39 #include <sys/time.h>
  40 #include <sys/resource.h>
  41 #include <errno.h>
  42 #endif /* G_THREAD_USE_PID_SURROGATE */
  43
  44 #ifdef HAVE_UNISTD_H
  45 #include <unistd.h>
  46 #endif
  47
  48 #include <string.h>
  49
  50 #include "glib.h"
  51 #include "gthreadinit.h"
  52
  53 #if GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P
  54 # define g_system_thread_equal_simple(thread1, thread2)                 \
  55    ((thread1).dummy_pointer == (thread2).dummy_pointer)
  56 # define g_system_thread_assign(dest, src)                              \
  57    ((dest).dummy_pointer = (src).dummy_pointer)
  58 #else /* GLIB_SIZEOF_SYSTEM_THREAD != SIZEOF_VOID_P */
  59 # define g_system_thread_equal_simple(thread1, thread2)                 \
  60    (memcmp (&(thread1), &(thread2), GLIB_SIZEOF_SYSTEM_THREAD) == 0)
  61 # define g_system_thread_assign(dest, src)                              \
  62    (memcpy (&(dest), &(src), GLIB_SIZEOF_SYSTEM_THREAD))
  63 #endif /* GLIB_SIZEOF_SYSTEM_THREAD == SIZEOF_VOID_P */
  64
  65 #define g_system_thread_equal(thread1, thread2)                         \
  66   (g_thread_functions_for_glib_use.thread_equal ?                       \
  67    g_thread_functions_for_glib_use.thread_equal (&(thread1), &(thread2)) :\
  68    g_system_thread_equal_simple((thread1), (thread2)))
  69
  70 GQuark
  71 g_thread_error_quark (void)
  72 {
  73   static GQuark quark;
  74   if (!quark)
  75     quark = g_quark_from_static_string ("g_thread_error");
  76   return quark;
  77 }
  78
  79 /* Keep this in sync with GRealThread in gmain.c! */
  80 typedef struct _GRealThread GRealThread;
  81 struct  _GRealThread
  82 {
  83   GThread thread;
  84   gpointer private_data;
  85   gpointer retval;
  86   GSystemThread system_thread;
  87 #ifdef G_THREAD_USE_PID_SURROGATE
  88   pid_t pid;
  89 #endif /* G_THREAD_USE_PID_SURROGATE */
  90 };
  91
  92 #ifdef G_THREAD_USE_PID_SURROGATE
  93 static gint priority_map[4];
  94 static gboolean prio_warned = FALSE;
  95 # define SET_PRIO(pid, prio) G_STMT_START{                              \
  96   gint error = setpriority (PRIO_PROCESS, (pid), priority_map[prio]);   \
  97   if (error == -1 && errno == EACCES && !prio_warned)                   \
  98     {                                                                   \
  99       prio_warned = TRUE;                                               \
 100       g_warning ("Priorities can only be increased by root.");          \
 101     }                                                                   \
 102   }G_STMT_END
 103 #endif /* G_THREAD_USE_PID_SURROGATE */
 104
 105 typedef struct _GStaticPrivateNode GStaticPrivateNode;
 106 struct _GStaticPrivateNode
 107 {
 108   gpointer       data;
 109   GDestroyNotify destroy;
 110 };
 111
 112 static void g_thread_cleanup (gpointer data);
 113 static void g_thread_fail (void);
 114
 115 /* Global variables */
 116
 117 static GSystemThread zero_thread; /* This is initialized to all zero */
 118 gboolean g_thread_use_default_impl = TRUE;
 119 gboolean g_threads_got_initialized = FALSE;
 120
 121 #if defined(G_PLATFORM_WIN32) && defined(__GNUC__)
 122 __declspec(dllexport)
 123 #endif
 124 GThreadFunctions g_thread_functions_for_glib_use = {
 125   (GMutex*(*)())g_thread_fail,                 /* mutex_new */
 126   NULL,                                        /* mutex_lock */
 127   NULL,                                        /* mutex_trylock */
 128   NULL,                                        /* mutex_unlock */
 129   NULL,                                        /* mutex_free */
 130   (GCond*(*)())g_thread_fail,                  /* cond_new */
 131   NULL,                                        /* cond_signal */
 132   NULL,                                        /* cond_broadcast */
 133   NULL,                                        /* cond_wait */
 134   NULL,                                        /* cond_timed_wait  */
 135   NULL,                                        /* cond_free */
 136   (GPrivate*(*)(GDestroyNotify))g_thread_fail, /* private_new */
 137   NULL,                                        /* private_get */
 138   NULL,                                        /* private_set */
 139   (void(*)(GThreadFunc, gpointer, gulong,
 140            gboolean, gboolean, GThreadPriority,
 141            gpointer, GError**))g_thread_fail,  /* thread_create */
 142   NULL,                                        /* thread_yield */
 143   NULL,                                        /* thread_join */
 144   NULL,                                        /* thread_exit */
 145   NULL,                                        /* thread_set_priority */
 146   NULL                                         /* thread_self */
 147 };
 148
 149 /* Local data */
 150
 151 static GMutex   *g_mutex_protect_static_mutex_allocation = NULL;
 152 static GPrivate *g_thread_specific_private = NULL;
 153 static GSList   *g_thread_all_threads = NULL;
 154 static GSList   *g_thread_free_indeces = NULL;
 155
 156 G_LOCK_DEFINE_STATIC (g_thread);
 157
 158 /* This must be called only once, before any threads are created.
 159  * It will only be called from g_thread_init() in -lgthread.
 160  */
 161 void
 162 g_thread_init_glib (void)
 163 {
 164   /* We let the main thread (the one that calls g_thread_init) inherit
 165    * the static_private data set before calling g_thread_init
 166    */
 167   GRealThread* main_thread = (GRealThread*) g_thread_self ();
 168
 169   g_mutex_protect_static_mutex_allocation = g_mutex_new ();
 170
 171   _g_convert_thread_init ();
 172   _g_rand_thread_init ();
 173   _g_main_thread_init ();
 174   _g_mem_thread_init ();
 175   _g_messages_thread_init ();
 176
 177 #ifdef G_THREAD_USE_PID_SURROGATE
 178   priority_map[G_THREAD_PRIORITY_NORMAL] =
 179     getpriority (PRIO_PROCESS, (getpid ()));
 180   priority_map[G_THREAD_PRIORITY_LOW] =
 181     MIN (20, priority_map[G_THREAD_PRIORITY_NORMAL] + 10);
 182   priority_map[G_THREAD_PRIORITY_HIGH] =
 183     MAX (-20, priority_map[G_THREAD_PRIORITY_NORMAL] - 10);
 184   priority_map[G_THREAD_PRIORITY_URGENT] =
 185     MAX (-20, priority_map[G_THREAD_PRIORITY_NORMAL] - 15);
 186 #endif /* G_THREAD_USE_PID_SURROGATE */
 187
 188   g_threads_got_initialized = TRUE;
 189
 190   g_thread_specific_private = g_private_new (g_thread_cleanup);
 191   g_private_set (g_thread_specific_private, main_thread);
 192   G_THREAD_UF (thread_self, (&main_thread->system_thread));
 193
 194   _g_mem_thread_private_init ();
 195   _g_messages_thread_private_init ();
 196
 197 }
 198
 199 void
 200 g_static_mutex_init (GStaticMutex *mutex)
 201 {
 202   static GStaticMutex init_mutex = G_STATIC_MUTEX_INIT;
 203
 204   g_return_if_fail (mutex);
 205
 206   *mutex = init_mutex;
 207 }
 208
 209 GMutex *
 210 g_static_mutex_get_mutex_impl (GMutex** mutex)
 211 {
 212   if (!g_thread_supported ())
 213     return NULL;
 214
 215   g_assert (g_mutex_protect_static_mutex_allocation);
 216
 217   g_mutex_lock (g_mutex_protect_static_mutex_allocation);
 218
 219   if (!(*mutex))
 220     *mutex = g_mutex_new ();
 221
 222   g_mutex_unlock (g_mutex_protect_static_mutex_allocation);
 223
 224   return *mutex;
 225 }
 226
 227 void
 228 g_static_mutex_free (GStaticMutex* mutex)
 229 {
 230   GMutex **runtime_mutex;
 231
 232   g_return_if_fail (mutex);
 233
 234   /* The runtime_mutex is the first (or only) member of GStaticMutex,
 235    * see both versions (of glibconfig.h) in configure.in */
 236   runtime_mutex = ((GMutex**)mutex);
 237
 238   if (*runtime_mutex)
 239     g_mutex_free (*runtime_mutex);
 240
 241   *runtime_mutex = NULL;
 242 }
 243
 244 void
 245 g_static_rec_mutex_init (GStaticRecMutex *mutex)
 246 {
 247   static GStaticRecMutex init_mutex = G_STATIC_REC_MUTEX_INIT;
 248
 249   g_return_if_fail (mutex);
 250
 251   *mutex = init_mutex;
 252 }
 253
 254 void
 255 g_static_rec_mutex_lock (GStaticRecMutex* mutex)
 256 {
 257   GSystemThread self;
 258
 259   g_return_if_fail (mutex);
 260
 261   if (!g_thread_supported ())
 262     return;
 263
 264   G_THREAD_UF (thread_self, (&self));
 265
 266   if (g_system_thread_equal (self, mutex->owner))
 267     {
 268       mutex->depth++;
 269       return;
 270     }
 271   g_static_mutex_lock (&mutex->mutex);
 272   g_system_thread_assign (mutex->owner, self);
 273   mutex->depth = 1;
 274 }
 275
 276 gboolean
 277 g_static_rec_mutex_trylock (GStaticRecMutex* mutex)
 278 {
 279   GSystemThread self;
 280
 281   g_return_val_if_fail (mutex, FALSE);
 282
 283   if (!g_thread_supported ())
 284     return TRUE;
 285
 286   G_THREAD_UF (thread_self, (&self));
 287
 288   if (g_system_thread_equal (self, mutex->owner))
 289     {
 290       mutex->depth++;
 291       return TRUE;
 292     }
 293
 294   if (!g_static_mutex_trylock (&mutex->mutex))
 295     return FALSE;
 296
 297   g_system_thread_assign (mutex->owner, self);
 298   mutex->depth = 1;
 299   return TRUE;
 300 }
 301
 302 void
 303 g_static_rec_mutex_unlock (GStaticRecMutex* mutex)
 304 {
 305   g_return_if_fail (mutex);
 306
 307   if (!g_thread_supported ())
 308     return;
 309
 310   if (mutex->depth > 1)
 311     {
 312       mutex->depth--;
 313       return;
 314     }
 315   g_system_thread_assign (mutex->owner, zero_thread);
 316   g_static_mutex_unlock (&mutex->mutex);
 317 }
 318
 319 void
 320 g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 321                                 guint            depth)
 322 {
 323   GSystemThread self;
 324   g_return_if_fail (mutex);
 325
 326   if (!g_thread_supported ())
 327     return;
 328
 329   G_THREAD_UF (thread_self, (&self));
 330
 331   if (g_system_thread_equal (self, mutex->owner))
 332     {
 333       mutex->depth += depth;
 334       return;
 335     }
 336   g_static_mutex_lock (&mutex->mutex);
 337   g_system_thread_assign (mutex->owner, self);
 338   mutex->depth = depth;
 339 }
 340
 341 guint
 342 g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex)
 343 {
 344   guint depth;
 345
 346   g_return_val_if_fail (mutex, 0);
 347
 348   if (!g_thread_supported ())
 349     return 1;
 350
 351   depth = mutex->depth;
 352
 353   g_system_thread_assign (mutex->owner, zero_thread);
 354   mutex->depth = 0;
 355   g_static_mutex_unlock (&mutex->mutex);
 356
 357   return depth;
 358 }
 359
 360 void
 361 g_static_rec_mutex_free (GStaticRecMutex *mutex)
 362 {
 363   g_return_if_fail (mutex);
 364
 365   g_static_mutex_free (&mutex->mutex);
 366 }
 367
 368 void
 369 g_static_private_init (GStaticPrivate *private_key)
 370 {
 371   private_key->index = 0;
 372 }
 373
 374 gpointer
 375 g_static_private_get (GStaticPrivate *private_key)
 376 {
 377   GRealThread *self = (GRealThread*) g_thread_self ();
 378   GArray *array;
 379
 380   array = self->private_data;
 381   if (!array)
 382     return NULL;
 383
 384   if (!private_key->index)
 385     return NULL;
 386   else if (private_key->index <= array->len)
 387     return g_array_index (array, GStaticPrivateNode,
 388                           private_key->index - 1).data;
 389   else
 390     return NULL;
 391 }
 392
 393 void
 394 g_static_private_set (GStaticPrivate *private_key,
 395                       gpointer        data,
 396                       GDestroyNotify  notify)
 397 {
 398   GRealThread *self = (GRealThread*) g_thread_self ();
 399   GArray *array;
 400   static guint next_index = 0;
 401   GStaticPrivateNode *node;
 402
 403   array = self->private_data;
 404   if (!array)
 405     {
 406       array = g_array_new (FALSE, TRUE, sizeof (GStaticPrivateNode));
 407       self->private_data = array;
 408     }
 409
 410   if (!private_key->index)
 411     {
 412       G_LOCK (g_thread);
 413
 414       if (!private_key->index)
 415         {
 416           if (g_thread_free_indeces)
 417             {
 418               private_key->index =
 419                 GPOINTER_TO_UINT (g_thread_free_indeces->data);
 420               g_thread_free_indeces =
 421                 g_slist_delete_link (g_thread_free_indeces,
 422                                      g_thread_free_indeces);
 423             }
 424           else
 425             private_key->index = ++next_index;
 426         }
 427
 428       G_UNLOCK (g_thread);
 429     }
 430
 431   if (private_key->index > array->len)
 432     g_array_set_size (array, private_key->index);
 433
 434   node = &g_array_index (array, GStaticPrivateNode, private_key->index - 1);
 435   if (node->destroy)
 436     {
 437       gpointer ddata = node->data;
 438       GDestroyNotify ddestroy = node->destroy;
 439
 440       node->data = data;
 441       node->destroy = notify;
 442
 443       ddestroy (ddata);
 444     }
 445   else
 446     {
 447       node->data = data;
 448       node->destroy = notify;
 449     }
 450 }
 451
 452 void
 453 g_static_private_free (GStaticPrivate *private_key)
 454 {
 455   guint index = private_key->index;
 456   GSList *list;
 457
 458   if (!index)
 459     return;
 460
 461   private_key->index = 0;
 462
 463   G_LOCK (g_thread);
 464   list =  g_thread_all_threads;
 465   while (list)
 466     {
 467       GRealThread *thread = list->data;
 468       GArray *array = thread->private_data;
 469       list = list->next;
 470
 471       if (array && index <= array->len)
 472         {
 473           GStaticPrivateNode *node = &g_array_index (array,
 474                                                      GStaticPrivateNode,
 475                                                      index - 1);
 476           gpointer ddata = node->data;
 477           GDestroyNotify ddestroy = node->destroy;
 478
 479           node->data = NULL;
 480           node->destroy = NULL;
 481
 482           if (ddestroy)
 483             {
 484               G_UNLOCK (g_thread);
 485               ddestroy (ddata);
 486               G_LOCK (g_thread);
 487               }
 488         }
 489     }
 490   g_thread_free_indeces = g_slist_prepend (g_thread_free_indeces,
 491                                            GUINT_TO_POINTER (index));
 492   G_UNLOCK (g_thread);
 493 }
 494
 495 static void
 496 g_thread_cleanup (gpointer data)
 497 {
 498   if (data)
 499     {
 500       GRealThread* thread = data;
 501       if (thread->private_data)
 502         {
 503           GArray* array = thread->private_data;
 504           guint i;
 505
 506           for (i = 0; i < array->len; i++ )
 507             {
 508               GStaticPrivateNode *node =
 509                 &g_array_index (array, GStaticPrivateNode, i);
 510               if (node->destroy)
 511                 node->destroy (node->data);
 512             }
 513           g_array_free (array, TRUE);
 514         }
 515
 516       /* We only free the thread structure, if it isn't joinable. If
 517          it is, the structure is freed in g_thread_join */
 518       if (!thread->thread.joinable)
 519         {
 520           G_LOCK (g_thread);
 521           g_thread_all_threads = g_slist_remove (g_thread_all_threads, data);
 522           G_UNLOCK (g_thread);
 523
 524           /* Just to make sure, this isn't used any more */
 525           g_system_thread_assign (thread->system_thread, zero_thread);
 526           g_free (thread);
 527         }
 528     }
 529 }
 530
 531 static void
 532 g_thread_fail (void)
 533 {
 534   g_error ("The thread system is not yet initialized.");
 535 }
 536
 537 static gpointer
 538 g_thread_create_proxy (gpointer data)
 539 {
 540   GRealThread* thread = data;
 541
 542   g_assert (data);
 543
 544 #ifdef G_THREAD_USE_PID_SURROGATE
 545   thread->pid = getpid ();
 546 #endif /* G_THREAD_USE_PID_SURROGATE */
 547
 548   /* This has to happen before G_LOCK, as that might call g_thread_self */
 549   g_private_set (g_thread_specific_private, data);
 550
 551   /* the lock makes sure, that thread->system_thread is written,
 552      before thread->thread.func is called. See g_thread_create. */
 553   G_LOCK (g_thread);
 554   G_UNLOCK (g_thread);
 555
 556 #ifdef G_THREAD_USE_PID_SURROGATE
 557   if (g_thread_use_default_impl)
 558     SET_PRIO (thread->pid, thread->thread.priority);
 559 #endif /* G_THREAD_USE_PID_SURROGATE */
 560
 561   thread->retval = thread->thread.func (thread->thread.data);
 562
 563   return NULL;
 564 }
 565
 566 GThread*
 567 g_thread_create_full (GThreadFunc                func,
 568                       gpointer           data,
 569                       gulong             stack_size,
 570                       gboolean           joinable,
 571                       gboolean           bound,
 572                       GThreadPriority    priority,
 573                       GError                **error)
 574 {
 575   GRealThread* result;
 576   GError *local_error = NULL;
 577   g_return_val_if_fail (func, NULL);
 578   g_return_val_if_fail (priority >= G_THREAD_PRIORITY_LOW, NULL);
 579   g_return_val_if_fail (priority <= G_THREAD_PRIORITY_URGENT, NULL);
 580
 581   result = g_new (GRealThread, 1);
 582
 583   result->thread.joinable = joinable;
 584   result->thread.priority = priority;
 585   result->thread.func = func;
 586   result->thread.data = data;
 587   result->private_data = NULL;
 588   G_LOCK (g_thread);
 589   G_THREAD_UF (thread_create, (g_thread_create_proxy, result,
 590                                stack_size, joinable, bound, priority,
 591                                &result->system_thread, &local_error));
 592   g_thread_all_threads = g_slist_prepend (g_thread_all_threads, result);
 593   G_UNLOCK (g_thread);
 594
 595   if (local_error)
 596     {
 597       g_propagate_error (error, local_error);
 598       g_free (result);
 599       return NULL;
 600     }
 601
 602   return (GThread*) result;
 603 }
 604
 605 void
 606 g_thread_exit (gpointer retval)
 607 {
 608   GRealThread* real = (GRealThread*) g_thread_self ();
 609   real->retval = retval;
 610   G_THREAD_CF (thread_exit, (void)0, ());
 611 }
 612
 613 gpointer
 614 g_thread_join (GThread* thread)
 615 {
 616   GRealThread* real = (GRealThread*) thread;
 617   gpointer retval;
 618
 619   g_return_val_if_fail (thread, NULL);
 620   g_return_val_if_fail (thread->joinable, NULL);
 621   g_return_val_if_fail (!g_system_thread_equal (real->system_thread,
 622                                                 zero_thread), NULL);
 623
 624   G_THREAD_UF (thread_join, (&real->system_thread));
 625
 626   retval = real->retval;
 627
 628   G_LOCK (g_thread);
 629   g_thread_all_threads = g_slist_remove (g_thread_all_threads, thread);
 630   G_UNLOCK (g_thread);
 631
 632   /* Just to make sure, this isn't used any more */
 633   thread->joinable = 0;
 634   g_system_thread_assign (real->system_thread, zero_thread);
 635
 636   /* the thread structure for non-joinable threads is freed upon
 637      thread end. We free the memory here. This will leave a loose end,
 638      if a joinable thread is not joined. */
 639
 640   g_free (thread);
 641
 642   return retval;
 643 }
 644
 645 void
 646 g_thread_set_priority (GThread* thread,
 647                        GThreadPriority priority)
 648 {
 649   GRealThread* real = (GRealThread*) thread;
 650
 651   g_return_if_fail (thread);
 652   g_return_if_fail (!g_system_thread_equal (real->system_thread, zero_thread));
 653   g_return_if_fail (priority >= G_THREAD_PRIORITY_LOW);
 654   g_return_if_fail (priority <= G_THREAD_PRIORITY_URGENT);
 655
 656   thread->priority = priority;
 657
 658 #ifdef G_THREAD_USE_PID_SURROGATE
 659   if (g_thread_use_default_impl)
 660     SET_PRIO (real->pid, priority);
 661   else
 662 #endif /* G_THREAD_USE_PID_SURROGATE */
 663     G_THREAD_CF (thread_set_priority, (void)0,
 664                  (&real->system_thread, priority));
 665 }
 666
 667 GThread*
 668 g_thread_self (void)
 669 {
 670   GRealThread* thread = g_private_get (g_thread_specific_private);
 671
 672   if (!thread)
 673     {
 674       /* If no thread data is available, provide and set one.  This
 675          can happen for the main thread and for threads, that are not
 676          created by GLib. */
 677       thread = g_new (GRealThread, 1);
 678       thread->thread.joinable = FALSE; /* This is a save guess */
 679       thread->thread.priority = G_THREAD_PRIORITY_NORMAL; /* This is
 680                                                              just a guess */
 681       thread->thread.func = NULL;
 682       thread->thread.data = NULL;
 683       thread->private_data = NULL;
 684
 685       if (g_thread_supported ())
 686         G_THREAD_UF (thread_self, (&thread->system_thread));
 687
 688 #ifdef G_THREAD_USE_PID_SURROGATE
 689       thread->pid = getpid ();
 690 #endif /* G_THREAD_USE_PID_SURROGATE */
 691
 692       g_private_set (g_thread_specific_private, thread);
 693
 694       G_LOCK (g_thread);
 695       g_thread_all_threads = g_slist_prepend (g_thread_all_threads, thread);
 696       G_UNLOCK (g_thread);
 697     }
 698
 699   return (GThread*)thread;
 700 }
 701
 702 void
 703 g_static_rw_lock_init (GStaticRWLock* lock)
 704 {
 705   static GStaticRWLock init_lock = G_STATIC_RW_LOCK_INIT;
 706
 707   g_return_if_fail (lock);
 708
 709   *lock = init_lock;
 710 }
 711
 712 static void inline
 713 g_static_rw_lock_wait (GCond** cond, GStaticMutex* mutex)
 714 {
 715   if (!*cond)
 716       *cond = g_cond_new ();
 717   g_cond_wait (*cond, g_static_mutex_get_mutex (mutex));
 718 }
 719
 720 static void inline
 721 g_static_rw_lock_signal (GStaticRWLock* lock)
 722 {
 723   if (lock->want_to_write && lock->write_cond)
 724     g_cond_signal (lock->write_cond);
 725   else if (lock->want_to_read && lock->read_cond)
 726     g_cond_broadcast (lock->read_cond);
 727 }
 728
 729 void
 730 g_static_rw_lock_reader_lock (GStaticRWLock* lock)
 731 {
 732   g_return_if_fail (lock);
 733
 734   if (!g_threads_got_initialized)
 735     return;
 736
 737   g_static_mutex_lock (&lock->mutex);
 738   lock->want_to_read++;
 739   while (lock->have_writer || lock->want_to_write)
 740     g_static_rw_lock_wait (&lock->read_cond, &lock->mutex);
 741   lock->want_to_read--;
 742   lock->read_counter++;
 743   g_static_mutex_unlock (&lock->mutex);
 744 }
 745
 746 gboolean
 747 g_static_rw_lock_reader_trylock (GStaticRWLock* lock)
 748 {
 749   gboolean ret_val = FALSE;
 750
 751   g_return_val_if_fail (lock, FALSE);
 752
 753   if (!g_threads_got_initialized)
 754     return TRUE;
 755
 756   g_static_mutex_lock (&lock->mutex);
 757   if (!lock->have_writer && !lock->want_to_write)
 758     {
 759       lock->read_counter++;
 760       ret_val = TRUE;
 761     }
 762   g_static_mutex_unlock (&lock->mutex);
 763   return ret_val;
 764 }
 765
 766 void
 767 g_static_rw_lock_reader_unlock  (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->read_counter--;
 776   if (lock->read_counter == 0)
 777     g_static_rw_lock_signal (lock);
 778   g_static_mutex_unlock (&lock->mutex);
 779 }
 780
 781 void
 782 g_static_rw_lock_writer_lock (GStaticRWLock* lock)
 783 {
 784   g_return_if_fail (lock);
 785
 786   if (!g_threads_got_initialized)
 787     return;
 788
 789   g_static_mutex_lock (&lock->mutex);
 790   lock->want_to_write++;
 791   while (lock->have_writer || lock->read_counter)
 792     g_static_rw_lock_wait (&lock->write_cond, &lock->mutex);
 793   lock->want_to_write--;
 794   lock->have_writer = TRUE;
 795   g_static_mutex_unlock (&lock->mutex);
 796 }
 797
 798 gboolean
 799 g_static_rw_lock_writer_trylock (GStaticRWLock* lock)
 800 {
 801   gboolean ret_val = FALSE;
 802
 803   g_return_val_if_fail (lock, FALSE);
 804
 805   if (!g_threads_got_initialized)
 806     return TRUE;
 807
 808   g_static_mutex_lock (&lock->mutex);
 809   if (!lock->have_writer && !lock->read_counter)
 810     {
 811       lock->have_writer = TRUE;
 812       ret_val = TRUE;
 813     }
 814   g_static_mutex_unlock (&lock->mutex);
 815   return ret_val;
 816 }
 817
 818 void
 819 g_static_rw_lock_writer_unlock (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->have_writer = FALSE;
 828   g_static_rw_lock_signal (lock);
 829   g_static_mutex_unlock (&lock->mutex);
 830 }
 831
 832 void
 833 g_static_rw_lock_free (GStaticRWLock* lock)
 834 {
 835   g_return_if_fail (lock);
 836
 837   if (lock->read_cond)
 838     {
 839       g_cond_free (lock->read_cond);
 840       lock->read_cond = NULL;
 841     }
 842   if (lock->write_cond)
 843     {
 844       g_cond_free (lock->write_cond);
 845       lock->write_cond = NULL;
 846     }
 847   g_static_mutex_free (&lock->mutex);
 848 }