glib/gthread.h

   1 /* GLIB - Library of useful routines for C programming
   2  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GLib Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #ifndef __G_THREAD_H__
  28 #define __G_THREAD_H__
  29
  30 #include <gerror.h>
  31 #include <gtypes.h>
  32
  33 G_BEGIN_DECLS
  34
  35 /* GLib Thread support
  36  */
  37
  38 extern GQuark g_thread_error_quark (void);
  39 #define G_THREAD_ERROR g_thread_error_quark ()
  40
  41 typedef enum
  42 {
  43   G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
  44 } GThreadError;
  45
  46 typedef gpointer (*GThreadFunc) (gpointer data);
  47
  48 typedef enum
  49 {
  50   G_THREAD_PRIORITY_LOW,
  51   G_THREAD_PRIORITY_NORMAL,
  52   G_THREAD_PRIORITY_HIGH,
  53   G_THREAD_PRIORITY_URGENT
  54 } GThreadPriority;
  55
  56 typedef struct _GThread         GThread;
  57 struct  _GThread
  58 {
  59   GThreadFunc func;
  60   gpointer data;
  61   gboolean joinable;
  62   gboolean bound;
  63   GThreadPriority priority;
  64 };
  65
  66 typedef struct _GMutex          GMutex;
  67 typedef struct _GCond           GCond;
  68 typedef struct _GPrivate        GPrivate;
  69 typedef struct _GStaticPrivate  GStaticPrivate;
  70
  71 typedef struct _GThreadFunctions GThreadFunctions;
  72 struct _GThreadFunctions
  73 {
  74   GMutex*  (*mutex_new)           (void);
  75   void     (*mutex_lock)          (GMutex               *mutex);
  76   gboolean (*mutex_trylock)       (GMutex               *mutex);
  77   void     (*mutex_unlock)        (GMutex               *mutex);
  78   void     (*mutex_free)          (GMutex               *mutex);
  79   GCond*   (*cond_new)            (void);
  80   void     (*cond_signal)         (GCond                *cond);
  81   void     (*cond_broadcast)      (GCond                *cond);
  82   void     (*cond_wait)           (GCond                *cond,
  83                                    GMutex               *mutex);
  84   gboolean (*cond_timed_wait)     (GCond                *cond,
  85                                    GMutex               *mutex,
  86                                    GTimeVal             *end_time);
  87   void      (*cond_free)          (GCond                *cond);
  88   GPrivate* (*private_new)        (GDestroyNotify        destructor);
  89   gpointer  (*private_get)        (GPrivate             *private_key);
  90   void      (*private_set)        (GPrivate             *private_key,
  91                                    gpointer              data);
  92   void      (*thread_create)      (GThreadFunc           func,
  93                                    gpointer              data,
  94                                    gulong                stack_size,
  95                                    gboolean              joinable,
  96                                    gboolean              bound,
  97                                    GThreadPriority       priority,
  98                                    gpointer              thread,
  99                                    GError              **error);
 100   void      (*thread_yield)       (void);
 101   void      (*thread_join)        (gpointer              thread);
 102   void      (*thread_exit)        (void);
 103   void      (*thread_set_priority)(gpointer              thread,
 104                                    GThreadPriority       priority);
 105   void      (*thread_self)        (gpointer              thread);
 106 };
 107
 108 GLIB_VAR GThreadFunctions       g_thread_functions_for_glib_use;
 109 GLIB_VAR gboolean               g_thread_use_default_impl;
 110 GLIB_VAR gboolean               g_threads_got_initialized;
 111
 112 /* initializes the mutex/cond/private implementation for glib, might
 113  * only be called once, and must not be called directly or indirectly
 114  * from another glib-function, e.g. as a callback.
 115  */
 116 void    g_thread_init   (GThreadFunctions       *vtable);
 117
 118 /* Errorcheck mutexes. If you define G_ERRORCHECK_MUTEXES, then all
 119  * mutexes will check for re-locking and re-unlocking */
 120
 121 /* Initialize thread system with errorcheck mutexes. vtable must be
 122  * NULL. Do not call directly. Use #define G_ERRORCHECK_MUTEXES
 123  * instead.
 124  */
 125 void    g_thread_init_with_errorcheck_mutexes (GThreadFunctions* vtable);
 126
 127 /* A random number to recognize debug calls to g_mutex_... */
 128 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
 129
 130 #ifdef G_ERRORCHECK_MUTEXES
 131 #define g_thread_init(vtable) g_thread_init_with_errorcheck_mutexes (vtable)
 132 #endif
 133
 134 /* internal function for fallback static mutex implementation */
 135 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 136
 137 /* shorthands for conditional and unconditional function calls */
 138
 139 #define G_THREAD_UF(op, arglist)                                        \
 140     (*g_thread_functions_for_glib_use . op) arglist
 141 #define G_THREAD_CF(op, fail, arg)                                      \
 142     (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
 143 #define G_THREAD_ECF(op, fail, mutex, type)                             \
 144     (g_thread_supported () ? ((type(*)(GMutex*, gulong, gchar*))        \
 145       (*g_thread_functions_for_glib_use . op))                          \
 146      (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
 147
 148 #ifndef G_ERRORCHECK_MUTEXES
 149 # define g_mutex_lock(mutex)                                            \
 150     G_THREAD_CF (mutex_lock,     (void)0, (mutex))
 151 # define g_mutex_trylock(mutex)                                         \
 152     G_THREAD_CF (mutex_trylock,  TRUE,    (mutex))
 153 # define g_mutex_unlock(mutex)                                          \
 154     G_THREAD_CF (mutex_unlock,   (void)0, (mutex))
 155 # define g_mutex_free(mutex)                                            \
 156     G_THREAD_CF (mutex_free,     (void)0, (mutex))
 157 # define g_cond_wait(cond, mutex)                                       \
 158     G_THREAD_CF (cond_wait,      (void)0, (cond, mutex))
 159 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 160     G_THREAD_CF (cond_timed_wait, TRUE,   (cond, mutex, abs_time))
 161 #else /* G_ERRORCHECK_MUTEXES */
 162 # define g_mutex_lock(mutex)                                            \
 163     G_THREAD_ECF (mutex_lock,    (void)0, (mutex), void)
 164 # define g_mutex_trylock(mutex)                                         \
 165     G_THREAD_ECF (mutex_trylock, TRUE,    (mutex), gboolean)
 166 # define g_mutex_unlock(mutex)                                          \
 167     G_THREAD_ECF (mutex_unlock,  (void)0, (mutex), void)
 168 # define g_mutex_free(mutex)                                            \
 169     G_THREAD_ECF (mutex_free,    (void)0, (mutex), void)
 170 # define g_cond_wait(cond, mutex)                                       \
 171     (g_thread_supported () ? ((void(*)(GCond*, GMutex*, gulong, gchar*))\
 172       g_thread_functions_for_glib_use.cond_wait)                        \
 173         (cond, mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (void) 0)
 174 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 175     (g_thread_supported () ?                                            \
 176       ((gboolean(*)(GCond*, GMutex*, GTimeVal*, gulong, gchar*))        \
 177         g_thread_functions_for_glib_use.cond_timed_wait)                \
 178           (cond, mutex, abs_time, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : TRUE)
 179 #endif /* G_ERRORCHECK_MUTEXES */
 180
 181 #define g_thread_supported()    (g_threads_got_initialized)
 182 #define g_mutex_new()            G_THREAD_UF (mutex_new,      ())
 183 #define g_cond_new()             G_THREAD_UF (cond_new,       ())
 184 #define g_cond_signal(cond)      G_THREAD_CF (cond_signal,    (void)0, (cond))
 185 #define g_cond_broadcast(cond)   G_THREAD_CF (cond_broadcast, (void)0, (cond))
 186 #define g_cond_free(cond)        G_THREAD_CF (cond_free,      (void)0, (cond))
 187 #define g_private_new(destructor) G_THREAD_UF (private_new, (destructor))
 188 #define g_private_get(private_key) G_THREAD_CF (private_get, \
 189                                                 ((gpointer)private_key), \
 190                                                 (private_key))
 191 #define g_private_set(private_key, value) G_THREAD_CF (private_set, \
 192                                                        (void) (private_key = \
 193                                                         (GPrivate*) (value)), \
 194                                                        (private_key, value))
 195 #define g_thread_yield()              G_THREAD_CF (thread_yield, (void)0, ())
 196
 197 GThread* g_thread_create       (GThreadFunc            func,
 198                                 gpointer               data,
 199                                 gulong                 stack_size,
 200                                 gboolean               joinable,
 201                                 gboolean               bound,
 202                                 GThreadPriority        priority,
 203                                 GError               **error);
 204 GThread* g_thread_self         (void);
 205 void     g_thread_exit         (gpointer               retval);
 206 gpointer g_thread_join         (GThread               *thread);
 207
 208 void     g_thread_set_priority (GThread               *thread,
 209                                 GThreadPriority        priority);
 210
 211 /* GStaticMutexes can be statically initialized with the value
 212  * G_STATIC_MUTEX_INIT, and then they can directly be used, that is
 213  * much easier, than having to explicitly allocate the mutex before
 214  * use
 215  */
 216 #define g_static_mutex_lock(mutex) \
 217     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 218 #define g_static_mutex_trylock(mutex) \
 219     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 220 #define g_static_mutex_unlock(mutex) \
 221     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 222 void g_static_mutex_init (GStaticMutex *mutex);
 223 void g_static_mutex_free (GStaticMutex *mutex);
 224
 225 struct _GStaticPrivate
 226 {
 227   guint index;
 228 };
 229 #define G_STATIC_PRIVATE_INIT { 0 }
 230 void     g_static_private_init           (GStaticPrivate   *private_key);
 231 gpointer g_static_private_get            (GStaticPrivate   *private_key);
 232 void     g_static_private_set            (GStaticPrivate   *private_key,
 233                                           gpointer          data,
 234                                           GDestroyNotify    notify);
 235 void     g_static_private_free           (GStaticPrivate   *private_key);
 236
 237 typedef struct _GStaticRecMutex GStaticRecMutex;
 238 struct _GStaticRecMutex
 239 {
 240   GStaticMutex mutex;
 241   unsigned int depth;
 242   GSystemThread owner;
 243 };
 244
 245 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT }
 246 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 247 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 248 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 249 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 250 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 251                                          guint            depth);
 252 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 253 void     g_static_rec_mutex_free        (GStaticRecMutex *mutex);
 254
 255 typedef struct _GStaticRWLock GStaticRWLock;
 256 struct _GStaticRWLock
 257 {
 258   GStaticMutex mutex;
 259   GCond *read_cond;
 260   GCond *write_cond;
 261   guint read_counter;
 262   gboolean write;
 263   guint want_to_write;
 264 };
 265
 266 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, FALSE }
 267
 268 void      g_static_rw_lock_init           (GStaticRWLock* lock);
 269 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 270 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 271 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 272 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 273 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 274 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 275 void      g_static_rw_lock_free           (GStaticRWLock* lock);
 276
 277 /* these are some convenience macros that expand to nothing if GLib
 278  * was configured with --disable-threads. for using StaticMutexes,
 279  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 280  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 281  * declare such an globally defined lock. name is a unique identifier
 282  * for the protected varibale or code portion. locking, testing and
 283  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 284  * G_TRYLOCK() respectively.
 285  */
 286 extern void glib_dummy_decl (void);
 287 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 288 #ifdef  G_THREADS_ENABLED
 289 #  define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 290 #  define G_LOCK_DEFINE(name)           \
 291     GStaticMutex G_LOCK_NAME (name) = G_STATIC_MUTEX_INIT
 292 #  define G_LOCK_EXTERN(name)           extern GStaticMutex G_LOCK_NAME (name)
 293
 294 #  ifdef G_DEBUG_LOCKS
 295 #    define G_LOCK(name)                G_STMT_START{             \
 296         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 297                "file %s: line %d (%s): locking: %s ",             \
 298                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 299                #name);                                            \
 300         g_static_mutex_lock (&G_LOCK_NAME (name));                \
 301      }G_STMT_END
 302 #    define G_UNLOCK(name)              G_STMT_START{             \
 303         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 304                "file %s: line %d (%s): unlocking: %s ",           \
 305                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 306                #name);                                            \
 307        g_static_mutex_unlock (&G_LOCK_NAME (name));               \
 308      }G_STMT_END
 309 #    define G_TRYLOCK(name)                                       \
 310         (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 311                "file %s: line %d (%s): try locking: %s ",         \
 312                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 313                #name), g_static_mutex_trylock (&G_LOCK_NAME (name)))
 314 #  else  /* !G_DEBUG_LOCKS */
 315 #    define G_LOCK(name) g_static_mutex_lock       (&G_LOCK_NAME (name))
 316 #    define G_UNLOCK(name) g_static_mutex_unlock   (&G_LOCK_NAME (name))
 317 #    define G_TRYLOCK(name) g_static_mutex_trylock (&G_LOCK_NAME (name))
 318 #  endif /* !G_DEBUG_LOCKS */
 319 #else   /* !G_THREADS_ENABLED */
 320 #  define G_LOCK_DEFINE_STATIC(name)    extern void glib_dummy_decl (void)
 321 #  define G_LOCK_DEFINE(name)           extern void glib_dummy_decl (void)
 322 #  define G_LOCK_EXTERN(name)           extern void glib_dummy_decl (void)
 323 #  define G_LOCK(name)
 324 #  define G_UNLOCK(name)
 325 #  define G_TRYLOCK(name)               (TRUE)
 326 #endif  /* !G_THREADS_ENABLED */
 327
 328 G_END_DECLS
 329
 330 #endif /* __G_THREAD_H__ */
 331