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 #if defined(G_DISABLE_SINGLE_INCLUDES) && !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  28 #error "Only <glib.h> can be included directly."
  29 #endif
  30
  31 #ifndef __G_THREAD_H__
  32 #define __G_THREAD_H__
  33
  34 #include <glib/gerror.h>
  35 #include <glib/gutils.h>        /* for G_INLINE_FUNC */
  36 #include <glib/gatomic.h>       /* for g_atomic_pointer_get */
  37
  38 G_BEGIN_DECLS
  39
  40 /* GLib Thread support
  41  */
  42
  43 extern GQuark g_thread_error_quark (void);
  44 #define G_THREAD_ERROR g_thread_error_quark ()
  45
  46 typedef enum
  47 {
  48   G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
  49 } GThreadError;
  50
  51 typedef gpointer (*GThreadFunc) (gpointer data);
  52
  53 /* This is "deprecated", but we can't actually remove it since
  54  * g_thread_create_full takes it.
  55  */
  56 typedef enum
  57 {
  58   G_THREAD_PRIORITY_LOW,
  59   G_THREAD_PRIORITY_NORMAL,
  60   G_THREAD_PRIORITY_HIGH,
  61   G_THREAD_PRIORITY_URGENT
  62 } GThreadPriority;
  63
  64 typedef struct _GThread         GThread;
  65 struct  _GThread
  66 {
  67   /*< private >*/
  68   GThreadFunc func;
  69   gpointer data;
  70   gboolean joinable;
  71   GThreadPriority priority;
  72 };
  73
  74 typedef struct _GMutex          GMutex;
  75 typedef struct _GCond           GCond;
  76 typedef struct _GPrivate        GPrivate;
  77 typedef struct _GStaticPrivate  GStaticPrivate;
  78
  79 #ifdef G_OS_WIN32
  80
  81 #define G_MUTEX_INIT { NULL }
  82 struct _GMutex
  83 {
  84     gpointer impl;
  85 };
  86
  87 #define G_COND_INIT { NULL }
  88 struct _GCond
  89 {
  90     gpointer impl;
  91 };
  92 #else
  93
  94 #include <pthread.h>
  95
  96 #define G_MUTEX_INIT { PTHREAD_MUTEX_INITIALIZER }
  97 struct _GMutex
  98 {
  99   pthread_mutex_t impl;
 100 };
 101
 102 #define G_COND_INIT { PTHREAD_COND_INITIALIZER }
 103 struct _GCond
 104 {
 105   pthread_cond_t impl;
 106 };
 107
 108 #endif
 109
 110 typedef struct _GThreadFunctions GThreadFunctions;
 111 struct _GThreadFunctions
 112 {
 113   GMutex*  (*mutex_new)           (void);
 114   void     (*mutex_lock)          (GMutex               *mutex);
 115   gboolean (*mutex_trylock)       (GMutex               *mutex);
 116   void     (*mutex_unlock)        (GMutex               *mutex);
 117   void     (*mutex_free)          (GMutex               *mutex);
 118   GCond*   (*cond_new)            (void);
 119   void     (*cond_signal)         (GCond                *cond);
 120   void     (*cond_broadcast)      (GCond                *cond);
 121   void     (*cond_wait)           (GCond                *cond,
 122                                    GMutex               *mutex);
 123   gboolean (*cond_timed_wait)     (GCond                *cond,
 124                                    GMutex               *mutex,
 125                                    GTimeVal             *end_time);
 126   void      (*cond_free)          (GCond                *cond);
 127   GPrivate* (*private_new)        (GDestroyNotify        destructor);
 128   gpointer  (*private_get)        (GPrivate             *private_key);
 129   void      (*private_set)        (GPrivate             *private_key,
 130                                    gpointer              data);
 131   void      (*thread_create)      (GThreadFunc           func,
 132                                    gpointer              data,
 133                                    gulong                stack_size,
 134                                    gboolean              joinable,
 135                                    gboolean              bound,
 136                                    GThreadPriority       priority,
 137                                    gpointer              thread,
 138                                    GError              **error);
 139   void      (*thread_yield)       (void);
 140   void      (*thread_join)        (gpointer              thread);
 141   void      (*thread_exit)        (void);
 142   void      (*thread_set_priority)(gpointer              thread,
 143                                    GThreadPriority       priority);
 144   void      (*thread_self)        (gpointer              thread);
 145   gboolean  (*thread_equal)       (gpointer              thread1,
 146                                    gpointer              thread2);
 147 };
 148
 149 GLIB_VAR GThreadFunctions       g_thread_functions_for_glib_use;
 150 GLIB_VAR gboolean               g_thread_use_default_impl;
 151 GLIB_VAR gboolean               g_threads_got_initialized;
 152
 153 #ifndef G_DISABLE_DEPRECATED
 154 GLIB_VAR guint64   (*g_thread_gettime) (void);
 155 #endif
 156
 157 /* initializes the mutex/cond/private implementation for glib, might
 158  * only be called once, and must not be called directly or indirectly
 159  * from another glib-function, e.g. as a callback.
 160  */
 161 void    g_thread_init   (GThreadFunctions       *vtable);
 162
 163 /* Checks if thread support is initialized.  Identical to the
 164  * g_thread_supported macro but provided for language bindings.
 165  */
 166 gboolean g_thread_get_initialized (void);
 167
 168 /* A random number to recognize debug calls to g_mutex_... */
 169 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
 170
 171 /* internal function for fallback static mutex implementation */
 172 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 173
 174 /* shorthands for conditional and unconditional function calls */
 175
 176 #define G_THREAD_UF(op, arglist)                                        \
 177     (*g_thread_functions_for_glib_use . op) arglist
 178 #define G_THREAD_CF(op, fail, arg)                                      \
 179     (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
 180 #define G_THREAD_ECF(op, fail, mutex, type)                             \
 181     (g_thread_supported () ?                                            \
 182       ((type(*)(GMutex*, const gulong, gchar const*))                   \
 183       (*g_thread_functions_for_glib_use . op))                          \
 184      (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
 185
 186
 187
 188 #if defined(G_THREADS_MANDATORY)
 189 #define g_thread_supported()     1
 190 #else
 191 #define g_thread_supported()    (g_threads_got_initialized)
 192 #endif
 193
 194 #define g_thread_create(func, data, joinable, error) \
 195   (g_thread_create_full (func, data, 0, joinable, FALSE, 0, error))
 196
 197 GThread* g_thread_create_full  (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 void     g_thread_yield        (void);
 208
 209 #ifndef G_DISABLE_DEPRECATED
 210 void     g_thread_set_priority (GThread               *thread,
 211                                 GThreadPriority        priority);
 212 #endif
 213
 214 #ifdef G_OS_WIN32
 215 typedef GMutex * GStaticMutex;
 216 #define G_STATIC_MUTEX_INIT NULL
 217 #define g_static_mutex_get_mutex g_static_mutex_get_mutex_impl
 218 #else /* G_OS_WIN32 */
 219 typedef struct {
 220   struct _GMutex *unused;
 221   GMutex mutex;
 222 } GStaticMutex;
 223 #define G_STATIC_MUTEX_INIT { NULL, G_MUTEX_INIT }
 224 #define g_static_mutex_get_mutex(s) (&(s)->mutex)
 225 #endif /* G_OS_WIN32 */
 226
 227 #define g_static_mutex_lock(mutex) \
 228     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 229 #define g_static_mutex_trylock(mutex) \
 230     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 231 #define g_static_mutex_unlock(mutex) \
 232     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 233 void g_static_mutex_init (GStaticMutex *mutex);
 234 void g_static_mutex_free (GStaticMutex *mutex);
 235
 236 struct _GStaticPrivate
 237 {
 238   /*< private >*/
 239   guint index;
 240 };
 241 #define G_STATIC_PRIVATE_INIT { 0 }
 242 void     g_static_private_init           (GStaticPrivate   *private_key);
 243 gpointer g_static_private_get            (GStaticPrivate   *private_key);
 244 void     g_static_private_set            (GStaticPrivate   *private_key,
 245                                           gpointer          data,
 246                                           GDestroyNotify    notify);
 247 void     g_static_private_free           (GStaticPrivate   *private_key);
 248
 249 typedef struct _GStaticRecMutex GStaticRecMutex;
 250 struct _GStaticRecMutex
 251 {
 252   /*< private >*/
 253   GStaticMutex mutex;
 254   guint depth;
 255   GSystemThread owner;
 256 };
 257
 258 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT, 0, {{0, 0, 0, 0}} }
 259 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 260 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 261 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 262 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 263 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 264                                          guint            depth);
 265 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 266 void     g_static_rec_mutex_free        (GStaticRecMutex *mutex);
 267
 268 typedef struct _GStaticRWLock GStaticRWLock;
 269 struct _GStaticRWLock
 270 {
 271   /*< private >*/
 272   GStaticMutex mutex;
 273   GCond *read_cond;
 274   GCond *write_cond;
 275   guint read_counter;
 276   gboolean have_writer;
 277   guint want_to_read;
 278   guint want_to_write;
 279 };
 280
 281 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, 0, 0 }
 282
 283 void      g_static_rw_lock_init           (GStaticRWLock* lock);
 284 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 285 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 286 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 287 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 288 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 289 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 290 void      g_static_rw_lock_free           (GStaticRWLock* lock);
 291
 292 void      g_thread_foreach                (GFunc          thread_func,
 293                                            gpointer       user_data);
 294
 295 typedef enum
 296 {
 297   G_ONCE_STATUS_NOTCALLED,
 298   G_ONCE_STATUS_PROGRESS,
 299   G_ONCE_STATUS_READY
 300 } GOnceStatus;
 301
 302 typedef struct _GOnce GOnce;
 303 struct _GOnce
 304 {
 305   volatile GOnceStatus status;
 306   volatile gpointer retval;
 307 };
 308
 309 #define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
 310
 311 gpointer g_once_impl (GOnce *once, GThreadFunc func, gpointer arg);
 312
 313 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 314 # define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
 315 #else /* !G_ATOMIC_OP_MEMORY_BARRIER_NEEDED*/
 316 # define g_once(once, func, arg) \
 317   (((once)->status == G_ONCE_STATUS_READY) ? \
 318    (once)->retval : \
 319    g_once_impl ((once), (func), (arg)))
 320 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 321
 322 /* initialize-once guards, keyed by value_location */
 323 G_INLINE_FUNC gboolean  g_once_init_enter       (volatile gsize *value_location);
 324 gboolean                g_once_init_enter_impl  (volatile gsize *value_location);
 325 void                    g_once_init_leave       (volatile gsize *value_location,
 326                                                  gsize           initialization_value);
 327 #if defined (G_CAN_INLINE) || defined (__G_THREAD_C__)
 328 G_INLINE_FUNC gboolean
 329 g_once_init_enter (volatile gsize *value_location)
 330 {
 331   if G_LIKELY ((gpointer) g_atomic_pointer_get (value_location) != NULL)
 332     return FALSE;
 333   else
 334     return g_once_init_enter_impl (value_location);
 335 }
 336 #endif /* G_CAN_INLINE || __G_THREAD_C__ */
 337
 338 /* these are some convenience macros that expand to nothing if GLib
 339  * was configured with --disable-threads. for using StaticMutexes,
 340  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 341  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 342  * declare such an globally defined lock. name is a unique identifier
 343  * for the protected varibale or code portion. locking, testing and
 344  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 345  * G_TRYLOCK() respectively.
 346  */
 347 extern void glib_dummy_decl (void);
 348 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 349 #define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 350 #define G_LOCK_DEFINE(name)           \
 351   GMutex G_LOCK_NAME (name) = G_MUTEX_INIT
 352 #define G_LOCK_EXTERN(name)           extern GMutex G_LOCK_NAME (name)
 353
 354 #ifdef G_DEBUG_LOCKS
 355 #  define G_LOCK(name)                G_STMT_START{             \
 356       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 357              "file %s: line %d (%s): locking: %s ",             \
 358              __FILE__,        __LINE__, G_STRFUNC,              \
 359              #name);                                            \
 360       g_mutex_lock (&G_LOCK_NAME (name));                       \
 361    }G_STMT_END
 362 #  define G_UNLOCK(name)              G_STMT_START{             \
 363       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 364              "file %s: line %d (%s): unlocking: %s ",           \
 365              __FILE__,        __LINE__, G_STRFUNC,              \
 366              #name);                                            \
 367      g_mutex_unlock (&G_LOCK_NAME (name));                      \
 368    }G_STMT_END
 369 #  define G_TRYLOCK(name)                                       \
 370       (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 371              "file %s: line %d (%s): try locking: %s ",         \
 372              __FILE__,        __LINE__, G_STRFUNC,              \
 373              #name), g_mutex_trylock (&G_LOCK_NAME (name)))
 374 #else  /* !G_DEBUG_LOCKS */
 375 #  define G_LOCK(name) g_mutex_lock       (&G_LOCK_NAME (name))
 376 #  define G_UNLOCK(name) g_mutex_unlock   (&G_LOCK_NAME (name))
 377 #  define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
 378 #endif /* !G_DEBUG_LOCKS */
 379
 380
 381 void                    g_mutex_init                                    (GMutex         *mutex);
 382 void                    g_mutex_clear                                   (GMutex         *mutex);
 383
 384 void                    g_mutex_lock                                    (GMutex         *mutex);
 385 void                    g_mutex_unlock                                  (GMutex         *mutex);
 386 gboolean                g_mutex_trylock                                 (GMutex         *mutex);
 387
 388 void                    g_cond_init                                     (GCond          *cond);
 389 void                    g_cond_clear                                    (GCond          *cond);
 390
 391 void                    g_cond_wait                                     (GCond          *cond,
 392                                                                          GMutex         *mutex);
 393 void                    g_cond_signal                                   (GCond          *cond);
 394 void                    g_cond_broadcast                                (GCond          *cond);
 395 gboolean                g_cond_timed_wait                               (GCond          *cond,
 396                                                                          GMutex         *mutex,
 397                                                                          GTimeVal       *timeval);
 398 gboolean                g_cond_timedwait                                (GCond          *cond,
 399                                                                          GMutex         *mutex,
 400                                                                          gint64          abs_time);
 401
 402 GMutex *                g_mutex_new                                     (void);
 403 void                    g_mutex_free                                    (GMutex         *mutex);
 404 GCond *                 g_cond_new                                      (void);
 405 void                    g_cond_free                                     (GCond          *cond);
 406
 407 GPrivate *              g_private_new                                   (GDestroyNotify  notify);
 408 gpointer                g_private_get                                   (GPrivate       *key);
 409 void                    g_private_set                                   (GPrivate       *key,
 410                                                                          gpointer        value);
 411
 412 G_END_DECLS
 413
 414 #endif /* __G_THREAD_H__ */