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 <glib/gerror.h>
  31 #include <glib/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   GThreadPriority priority;
  63 };
  64
  65 typedef struct _GMutex          GMutex;
  66 typedef struct _GCond           GCond;
  67 typedef struct _GPrivate        GPrivate;
  68 typedef struct _GStaticPrivate  GStaticPrivate;
  69
  70 typedef struct _GThreadFunctions GThreadFunctions;
  71 struct _GThreadFunctions
  72 {
  73   GMutex*  (*mutex_new)           (void);
  74   void     (*mutex_lock)          (GMutex               *mutex);
  75   gboolean (*mutex_trylock)       (GMutex               *mutex);
  76   void     (*mutex_unlock)        (GMutex               *mutex);
  77   void     (*mutex_free)          (GMutex               *mutex);
  78   GCond*   (*cond_new)            (void);
  79   void     (*cond_signal)         (GCond                *cond);
  80   void     (*cond_broadcast)      (GCond                *cond);
  81   void     (*cond_wait)           (GCond                *cond,
  82                                    GMutex               *mutex);
  83   gboolean (*cond_timed_wait)     (GCond                *cond,
  84                                    GMutex               *mutex,
  85                                    GTimeVal             *end_time);
  86   void      (*cond_free)          (GCond                *cond);
  87   GPrivate* (*private_new)        (GDestroyNotify        destructor);
  88   gpointer  (*private_get)        (GPrivate             *private_key);
  89   void      (*private_set)        (GPrivate             *private_key,
  90                                    gpointer              data);
  91   void      (*thread_create)      (GThreadFunc           func,
  92                                    gpointer              data,
  93                                    gulong                stack_size,
  94                                    gboolean              joinable,
  95                                    gboolean              bound,
  96                                    GThreadPriority       priority,
  97                                    gpointer              thread,
  98                                    GError              **error);
  99   void      (*thread_yield)       (void);
 100   void      (*thread_join)        (gpointer              thread);
 101   void      (*thread_exit)        (void);
 102   void      (*thread_set_priority)(gpointer              thread,
 103                                    GThreadPriority       priority);
 104   void      (*thread_self)        (gpointer              thread);
 105   gboolean  (*thread_equal)       (gpointer              thread1,
 106                                    gpointer              thread2);
 107 };
 108
 109 GLIB_VAR GThreadFunctions       g_thread_functions_for_glib_use;
 110 GLIB_VAR gboolean               g_thread_use_default_impl;
 111 GLIB_VAR gboolean               g_threads_got_initialized;
 112
 113 /* initializes the mutex/cond/private implementation for glib, might
 114  * only be called once, and must not be called directly or indirectly
 115  * from another glib-function, e.g. as a callback.
 116  */
 117 void    g_thread_init   (GThreadFunctions       *vtable);
 118
 119 /* Errorcheck mutexes. If you define G_ERRORCHECK_MUTEXES, then all
 120  * mutexes will check for re-locking and re-unlocking */
 121
 122 /* Initialize thread system with errorcheck mutexes. vtable must be
 123  * NULL. Do not call directly. Use #define G_ERRORCHECK_MUTEXES
 124  * instead.
 125  */
 126 void    g_thread_init_with_errorcheck_mutexes (GThreadFunctions* vtable);
 127
 128 /* A random number to recognize debug calls to g_mutex_... */
 129 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
 130
 131 #ifdef G_ERRORCHECK_MUTEXES
 132 #define g_thread_init(vtable) g_thread_init_with_errorcheck_mutexes (vtable)
 133 #endif
 134
 135 /* internal function for fallback static mutex implementation */
 136 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 137
 138 /* shorthands for conditional and unconditional function calls */
 139
 140 #define G_THREAD_UF(op, arglist)                                        \
 141     (*g_thread_functions_for_glib_use . op) arglist
 142 #define G_THREAD_CF(op, fail, arg)                                      \
 143     (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
 144 #define G_THREAD_ECF(op, fail, mutex, type)                             \
 145     (g_thread_supported () ? ((type(*)(GMutex*, gulong, gchar*))        \
 146       (*g_thread_functions_for_glib_use . op))                          \
 147      (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
 148
 149 #ifndef G_ERRORCHECK_MUTEXES
 150 # define g_mutex_lock(mutex)                                            \
 151     G_THREAD_CF (mutex_lock,     (void)0, (mutex))
 152 # define g_mutex_trylock(mutex)                                         \
 153     G_THREAD_CF (mutex_trylock,  TRUE,    (mutex))
 154 # define g_mutex_unlock(mutex)                                          \
 155     G_THREAD_CF (mutex_unlock,   (void)0, (mutex))
 156 # define g_mutex_free(mutex)                                            \
 157     G_THREAD_CF (mutex_free,     (void)0, (mutex))
 158 # define g_cond_wait(cond, mutex)                                       \
 159     G_THREAD_CF (cond_wait,      (void)0, (cond, mutex))
 160 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 161     G_THREAD_CF (cond_timed_wait, TRUE,   (cond, mutex, abs_time))
 162 #else /* G_ERRORCHECK_MUTEXES */
 163 # define g_mutex_lock(mutex)                                            \
 164     G_THREAD_ECF (mutex_lock,    (void)0, (mutex), void)
 165 # define g_mutex_trylock(mutex)                                         \
 166     G_THREAD_ECF (mutex_trylock, TRUE,    (mutex), gboolean)
 167 # define g_mutex_unlock(mutex)                                          \
 168     G_THREAD_ECF (mutex_unlock,  (void)0, (mutex), void)
 169 # define g_mutex_free(mutex)                                            \
 170     G_THREAD_ECF (mutex_free,    (void)0, (mutex), void)
 171 # define g_cond_wait(cond, mutex)                                       \
 172     (g_thread_supported () ? ((void(*)(GCond*, GMutex*, gulong, gchar*))\
 173       g_thread_functions_for_glib_use.cond_wait)                        \
 174         (cond, mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (void) 0)
 175 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 176     (g_thread_supported () ?                                            \
 177       ((gboolean(*)(GCond*, GMutex*, GTimeVal*, gulong, gchar*))        \
 178         g_thread_functions_for_glib_use.cond_timed_wait)                \
 179           (cond, mutex, abs_time, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : TRUE)
 180 #endif /* G_ERRORCHECK_MUTEXES */
 181
 182 #define g_thread_supported()    (g_threads_got_initialized)
 183 #define g_mutex_new()            G_THREAD_UF (mutex_new,      ())
 184 #define g_cond_new()             G_THREAD_UF (cond_new,       ())
 185 #define g_cond_signal(cond)      G_THREAD_CF (cond_signal,    (void)0, (cond))
 186 #define g_cond_broadcast(cond)   G_THREAD_CF (cond_broadcast, (void)0, (cond))
 187 #define g_cond_free(cond)        G_THREAD_CF (cond_free,      (void)0, (cond))
 188 #define g_private_new(destructor) G_THREAD_UF (private_new, (destructor))
 189 #define g_private_get(private_key) G_THREAD_CF (private_get, \
 190                                                 ((gpointer)private_key), \
 191                                                 (private_key))
 192 #define g_private_set(private_key, value) G_THREAD_CF (private_set, \
 193                                                        (void) (private_key = \
 194                                                         (GPrivate*) (value)), \
 195                                                        (private_key, value))
 196 #define g_thread_yield()              G_THREAD_CF (thread_yield, (void)0, ())
 197
 198 #define g_thread_create(func, data, joinable, error)                    \
 199   (g_thread_create_full (func, data, 0, joinable, FALSE,                \
 200                          G_THREAD_PRIORITY_NORMAL, error))
 201
 202 GThread* g_thread_create_full  (GThreadFunc            func,
 203                                 gpointer               data,
 204                                 gulong                 stack_size,
 205                                 gboolean               joinable,
 206                                 gboolean               bound,
 207                                 GThreadPriority        priority,
 208                                 GError               **error);
 209 GThread* g_thread_self         (void);
 210 void     g_thread_exit         (gpointer               retval);
 211 gpointer g_thread_join         (GThread               *thread);
 212
 213 void     g_thread_set_priority (GThread               *thread,
 214                                 GThreadPriority        priority);
 215
 216 /* GStaticMutexes can be statically initialized with the value
 217  * G_STATIC_MUTEX_INIT, and then they can directly be used, that is
 218  * much easier, than having to explicitly allocate the mutex before
 219  * use
 220  */
 221 #define g_static_mutex_lock(mutex) \
 222     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 223 #define g_static_mutex_trylock(mutex) \
 224     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 225 #define g_static_mutex_unlock(mutex) \
 226     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 227 void g_static_mutex_init (GStaticMutex *mutex);
 228 void g_static_mutex_free (GStaticMutex *mutex);
 229
 230 struct _GStaticPrivate
 231 {
 232   guint index;
 233 };
 234 #define G_STATIC_PRIVATE_INIT { 0 }
 235 void     g_static_private_init           (GStaticPrivate   *private_key);
 236 gpointer g_static_private_get            (GStaticPrivate   *private_key);
 237 void     g_static_private_set            (GStaticPrivate   *private_key,
 238                                           gpointer          data,
 239                                           GDestroyNotify    notify);
 240 void     g_static_private_free           (GStaticPrivate   *private_key);
 241
 242 typedef struct _GStaticRecMutex GStaticRecMutex;
 243 struct _GStaticRecMutex
 244 {
 245   GStaticMutex mutex;
 246   unsigned int depth;
 247   GSystemThread owner;
 248 };
 249
 250 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT }
 251 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 252 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 253 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 254 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 255 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 256                                          guint            depth);
 257 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 258 void     g_static_rec_mutex_free        (GStaticRecMutex *mutex);
 259
 260 typedef struct _GStaticRWLock GStaticRWLock;
 261 struct _GStaticRWLock
 262 {
 263   GStaticMutex mutex;
 264   GCond *read_cond;
 265   GCond *write_cond;
 266   guint read_counter;
 267   gboolean write;
 268   guint want_to_read;
 269   guint want_to_write;
 270 };
 271
 272 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, 0, 0 }
 273
 274 void      g_static_rw_lock_init           (GStaticRWLock* lock);
 275 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 276 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 277 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 278 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 279 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 280 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 281 void      g_static_rw_lock_free           (GStaticRWLock* lock);
 282
 283 /* these are some convenience macros that expand to nothing if GLib
 284  * was configured with --disable-threads. for using StaticMutexes,
 285  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 286  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 287  * declare such an globally defined lock. name is a unique identifier
 288  * for the protected varibale or code portion. locking, testing and
 289  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 290  * G_TRYLOCK() respectively.
 291  */
 292 extern void glib_dummy_decl (void);
 293 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 294 #ifdef  G_THREADS_ENABLED
 295 #  define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 296 #  define G_LOCK_DEFINE(name)           \
 297     GStaticMutex G_LOCK_NAME (name) = G_STATIC_MUTEX_INIT
 298 #  define G_LOCK_EXTERN(name)           extern GStaticMutex G_LOCK_NAME (name)
 299
 300 #  ifdef G_DEBUG_LOCKS
 301 #    define G_LOCK(name)                G_STMT_START{             \
 302         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 303                "file %s: line %d (%s): locking: %s ",             \
 304                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 305                #name);                                            \
 306         g_static_mutex_lock (&G_LOCK_NAME (name));                \
 307      }G_STMT_END
 308 #    define G_UNLOCK(name)              G_STMT_START{             \
 309         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 310                "file %s: line %d (%s): unlocking: %s ",           \
 311                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 312                #name);                                            \
 313        g_static_mutex_unlock (&G_LOCK_NAME (name));               \
 314      }G_STMT_END
 315 #    define G_TRYLOCK(name)                                       \
 316         (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 317                "file %s: line %d (%s): try locking: %s ",         \
 318                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 319                #name), g_static_mutex_trylock (&G_LOCK_NAME (name)))
 320 #  else  /* !G_DEBUG_LOCKS */
 321 #    define G_LOCK(name) g_static_mutex_lock       (&G_LOCK_NAME (name))
 322 #    define G_UNLOCK(name) g_static_mutex_unlock   (&G_LOCK_NAME (name))
 323 #    define G_TRYLOCK(name) g_static_mutex_trylock (&G_LOCK_NAME (name))
 324 #  endif /* !G_DEBUG_LOCKS */
 325 #else   /* !G_THREADS_ENABLED */
 326 #  define G_LOCK_DEFINE_STATIC(name)    extern void glib_dummy_decl (void)
 327 #  define G_LOCK_DEFINE(name)           extern void glib_dummy_decl (void)
 328 #  define G_LOCK_EXTERN(name)           extern void glib_dummy_decl (void)
 329 #  define G_LOCK(name)
 330 #  define G_UNLOCK(name)
 331 #  define G_TRYLOCK(name)               (TRUE)
 332 #endif  /* !G_THREADS_ENABLED */
 333
 334 G_END_DECLS
 335
 336 #endif /* __G_THREAD_H__ */
 337