gthread/gthread-impl.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: thread related functions
   5  * Copyright 1998 Sebastian Wilhelmi; University of Karlsruhe
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2 of the License, or (at your option) any later version.
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with this library; if not, write to the
  19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20  * Boston, MA 02111-1307, USA.
  21  */
  22
  23 /*
  24  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  25  * file for a list of people on the GLib Team.  See the ChangeLog
  26  * files for a list of changes.  These files are distributed with
  27  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  28  */
  29
  30 /*
  31  * MT safe
  32  */
  33
  34 #include "config.h"
  35
  36 #include "glib.h"
  37 #include "gthreadprivate.h"
  38
  39 #ifdef G_THREADS_ENABLED
  40
  41 static GSystemThread zero_thread; /* This is initialized to all zero */
  42 static gboolean thread_system_already_initialized = FALSE;
  43 static gint g_thread_priority_map [G_THREAD_PRIORITY_URGENT + 1];
  44
  45 #include G_THREAD_SOURCE
  46
  47 #ifndef PRIORITY_LOW_VALUE
  48 # define PRIORITY_LOW_VALUE 0
  49 #endif
  50
  51 #ifndef PRIORITY_URGENT_VALUE
  52 # define PRIORITY_URGENT_VALUE 0
  53 #endif
  54
  55 #ifndef PRIORITY_NORMAL_VALUE
  56 # define PRIORITY_NORMAL_VALUE                                          \
  57   ((PRIORITY_LOW_VALUE * 6 + PRIORITY_URGENT_VALUE * 4) / 10)
  58 #endif /* PRIORITY_NORMAL_VALUE */
  59
  60 #ifndef PRIORITY_HIGH_VALUE
  61 # define PRIORITY_HIGH_VALUE                                            \
  62   ((PRIORITY_NORMAL_VALUE + PRIORITY_URGENT_VALUE * 2) / 3)
  63 #endif /* PRIORITY_HIGH_VALUE */
  64
  65 void g_mutex_init (void);
  66 void g_mem_init (void);
  67 void g_messages_init (void);
  68 void g_convert_init (void);
  69 void g_rand_init (void);
  70 void g_main_thread_init (void);
  71
  72 typedef struct _GMutexDebugInfo GMutexDebugInfo;
  73 struct _GMutexDebugInfo
  74 {
  75   gchar *location;
  76   GSystemThread owner;
  77 };
  78
  79 #define G_MUTEX_DEBUG_INFO(mutex)                                       \
  80   (((GMutexDebugInfo*)(((char*)mutex)+G_MUTEX_SIZE)))
  81
  82 static GMutex *
  83 g_mutex_new_errorcheck_impl (void)
  84 {
  85   GMutex *retval = g_thread_functions_for_glib_use_default.mutex_new ();
  86   GMutexDebugInfo *info;
  87   retval = g_realloc (retval, G_MUTEX_SIZE + sizeof (GMutexDebugInfo));
  88
  89   info = G_MUTEX_DEBUG_INFO (retval);
  90   g_system_thread_assign (info->owner, zero_thread);
  91   info->location = "invalid";
  92
  93   return retval;
  94 }
  95
  96 static void
  97 g_mutex_lock_errorcheck_impl (GMutex *mutex,
  98                               const gulong magic,
  99                               gchar * const location)
 100 {
 101   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 102   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 103
 104   GSystemThread self;
 105   g_thread_functions_for_glib_use.thread_self (&self);
 106
 107   if (g_system_thread_equal (info->owner, self))
 108     g_error ("Trying to recursivly lock a mutex at '%s', "
 109              "previously locked at '%s'",
 110              loc, info->location);
 111
 112   g_thread_functions_for_glib_use_default.mutex_lock (mutex);
 113
 114   g_system_thread_assign (info->owner, self);
 115   info->location = loc;
 116 }
 117
 118 static gboolean
 119 g_mutex_trylock_errorcheck_impl (GMutex *mutex,
 120                                  const gulong magic,
 121                                  gchar * const location)
 122 {
 123   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 124   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 125
 126   GSystemThread self;
 127   g_thread_functions_for_glib_use.thread_self (&self);
 128
 129   if (g_system_thread_equal (info->owner, self))
 130     g_error ("Trying to recursivly lock a mutex at '%s', "
 131              "previously locked at '%s'",
 132              loc, info->location);
 133
 134   if (!g_thread_functions_for_glib_use_default.mutex_trylock (mutex))
 135     return FALSE;
 136
 137   g_system_thread_assign (info->owner, self);
 138   info->location = loc;
 139
 140   return TRUE;
 141 }
 142
 143 static void
 144 g_mutex_unlock_errorcheck_impl (GMutex *mutex,
 145                                 const gulong magic,
 146                                 gchar * const location)
 147 {
 148   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 149   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 150
 151   GSystemThread self;
 152   g_thread_functions_for_glib_use.thread_self (&self);
 153
 154   if (g_system_thread_equal (info->owner, zero_thread))
 155     g_error ("Trying to unlock an unlocked mutex at '%s'", loc);
 156
 157   if (!g_system_thread_equal (info->owner, self))
 158     g_warning ("Trying to unlock a mutex at '%s', "
 159                "previously locked by a different thread at '%s'",
 160                loc, info->location);
 161
 162   g_system_thread_assign (info->owner, zero_thread);
 163   info->location = NULL;
 164
 165   g_thread_functions_for_glib_use_default.mutex_unlock (mutex);
 166 }
 167
 168 static void
 169 g_mutex_free_errorcheck_impl (GMutex *mutex,
 170                               const gulong magic,
 171                               gchar * const location)
 172 {
 173   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 174   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 175
 176   if (info && !g_system_thread_equal (info->owner, zero_thread))
 177     g_error ("Trying to free a locked mutex at '%s', "
 178              "which was previously locked at '%s'",
 179              loc, info->location);
 180
 181   g_thread_functions_for_glib_use_default.mutex_free (mutex);
 182 }
 183
 184 static void
 185 g_cond_wait_errorcheck_impl (GCond *cond,
 186                              GMutex *mutex,
 187                              const gulong magic,
 188                              gchar * const location)
 189 {
 190   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 191   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 192
 193   GSystemThread self;
 194   g_thread_functions_for_glib_use.thread_self (&self);
 195
 196   if (g_system_thread_equal (info->owner, zero_thread))
 197     g_error ("Trying to use an unlocked mutex in g_cond_wait() at '%s'", loc);
 198
 199   if (!g_system_thread_equal (info->owner, self))
 200     g_error ("Trying to use a mutex locked by another thread in "
 201              "g_cond_wait() at '%s'", loc);
 202
 203   g_system_thread_assign (info->owner, zero_thread);
 204   loc = info->location;
 205
 206   g_thread_functions_for_glib_use_default.cond_wait (cond, mutex);
 207
 208   g_system_thread_assign (info->owner, self);
 209   info->location = loc;
 210 }
 211
 212
 213 static gboolean
 214 g_cond_timed_wait_errorcheck_impl (GCond *cond,
 215                                    GMutex *mutex,
 216                                    GTimeVal *end_time,
 217                                    const gulong magic,
 218                                    gchar * const location)
 219 {
 220   GMutexDebugInfo *info = G_MUTEX_DEBUG_INFO (mutex);
 221   gchar *loc = (magic == G_MUTEX_DEBUG_MAGIC) ? location : "unknown";
 222   gboolean retval;
 223
 224   GSystemThread self;
 225   g_thread_functions_for_glib_use.thread_self (&self);
 226
 227   if (g_system_thread_equal (info->owner, zero_thread))
 228     g_error ("Trying to use an unlocked mutex in g_cond_timed_wait() at '%s'",
 229              loc);
 230
 231   if (!g_system_thread_equal (info->owner, self))
 232     g_error ("Trying to use a mutex locked by another thread in "
 233              "g_cond_timed_wait() at '%s'", loc);
 234
 235   g_system_thread_assign (info->owner, zero_thread);
 236   loc = info->location;
 237
 238   retval = g_thread_functions_for_glib_use_default.cond_timed_wait (cond,
 239                                                                     mutex,
 240                                                                     end_time);
 241
 242   g_system_thread_assign (info->owner, self);
 243   info->location = loc;
 244
 245   return retval;
 246 }
 247
 248
 249 /* unshadow function declaration. See gthread.h */
 250 #undef g_thread_init
 251
 252 void
 253 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
 254 {
 255   GThreadFunctions errorcheck_functions;
 256   if (init)
 257     g_error ("Errorcheck mutexes can only be used for native "
 258              "thread implementations. Sorry." );
 259
 260 #ifdef HAVE_G_THREAD_IMPL_INIT
 261   /* This isn't called in g_thread_init, as it doesn't think to get
 262    * the default implementation, so we have to call it on our own.
 263    *
 264    * We must call this before copying
 265    * g_thread_functions_for_glib_use_default as the
 266    * implementation-specific init function might modify the contents
 267    * of g_thread_functions_for_glib_use_default based on operating
 268    * system version, C library version, or whatever. */
 269   g_thread_impl_init();
 270 #endif /* HAVE_G_THREAD_IMPL_INIT */
 271
 272   errorcheck_functions = g_thread_functions_for_glib_use_default;
 273   errorcheck_functions.mutex_new = g_mutex_new_errorcheck_impl;
 274   errorcheck_functions.mutex_lock =
 275     (void (*)(GMutex *)) g_mutex_lock_errorcheck_impl;
 276   errorcheck_functions.mutex_trylock =
 277     (gboolean (*)(GMutex *)) g_mutex_trylock_errorcheck_impl;
 278   errorcheck_functions.mutex_unlock =
 279     (void (*)(GMutex *)) g_mutex_unlock_errorcheck_impl;
 280   errorcheck_functions.mutex_free =
 281     (void (*)(GMutex *)) g_mutex_free_errorcheck_impl;
 282   errorcheck_functions.cond_wait =
 283     (void (*)(GCond *, GMutex *)) g_cond_wait_errorcheck_impl;
 284   errorcheck_functions.cond_timed_wait =
 285     (gboolean (*)(GCond *, GMutex *, GTimeVal *))
 286     g_cond_timed_wait_errorcheck_impl;
 287
 288   g_thread_init (&errorcheck_functions);
 289 }
 290
 291 void
 292 g_thread_init (GThreadFunctions* init)
 293 {
 294   gboolean supported;
 295
 296   if (thread_system_already_initialized)
 297     {
 298       if (init != NULL)
 299         g_warning ("GThread system already initialized, ignoring custom thread implementation.");
 300
 301       return;
 302     }
 303
 304   thread_system_already_initialized = TRUE;
 305
 306   if (init == NULL)
 307     {
 308 #ifdef HAVE_G_THREAD_IMPL_INIT
 309       /* now do any initialization stuff required by the
 310        * implementation, but only if called with a NULL argument, of
 311        * course. Otherwise it's up to the user to do so. */
 312       g_thread_impl_init();
 313 #endif /* HAVE_G_THREAD_IMPL_INIT */
 314       init = &g_thread_functions_for_glib_use_default;
 315     }
 316   else
 317     g_thread_use_default_impl = FALSE;
 318
 319   g_thread_functions_for_glib_use = *init;
 320   if (g_thread_gettime_impl)
 321     g_thread_gettime = g_thread_gettime_impl;
 322
 323   supported = (init->mutex_new &&
 324                init->mutex_lock &&
 325                init->mutex_trylock &&
 326                init->mutex_unlock &&
 327                init->mutex_free &&
 328                init->cond_new &&
 329                init->cond_signal &&
 330                init->cond_broadcast &&
 331                init->cond_wait &&
 332                init->cond_timed_wait &&
 333                init->cond_free &&
 334                init->private_new &&
 335                init->private_get &&
 336                init->private_set &&
 337                init->thread_create &&
 338                init->thread_yield &&
 339                init->thread_join &&
 340                init->thread_exit &&
 341                init->thread_set_priority &&
 342                init->thread_self);
 343
 344   /* if somebody is calling g_thread_init (), it means that he wants to
 345    * have thread support, so check this
 346    */
 347   if (!supported)
 348     {
 349       if (g_thread_use_default_impl)
 350         g_error ("Threads are not supported on this platform.");
 351       else
 352         g_error ("The supplied thread function vector is invalid.");
 353     }
 354
 355   g_thread_priority_map [G_THREAD_PRIORITY_LOW] = PRIORITY_LOW_VALUE;
 356   g_thread_priority_map [G_THREAD_PRIORITY_NORMAL] = PRIORITY_NORMAL_VALUE;
 357   g_thread_priority_map [G_THREAD_PRIORITY_HIGH] = PRIORITY_HIGH_VALUE;
 358   g_thread_priority_map [G_THREAD_PRIORITY_URGENT] = PRIORITY_URGENT_VALUE;
 359
 360   g_thread_init_glib ();
 361 }
 362
 363 #else /* !G_THREADS_ENABLED */
 364
 365 void
 366 g_thread_init (GThreadFunctions* init)
 367 {
 368   g_error ("GLib thread support is disabled.");
 369 }
 370
 371 void
 372 g_thread_init_with_errorcheck_mutexes (GThreadFunctions* init)
 373 {
 374   g_error ("GLib thread support is disabled.");
 375 }
 376
 377 #endif /* !G_THREADS_ENABLED */