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 typedef enum
  54 {
  55   G_THREAD_PRIORITY_LOW,
  56   G_THREAD_PRIORITY_NORMAL,
  57   G_THREAD_PRIORITY_HIGH,
  58   G_THREAD_PRIORITY_URGENT
  59 } GThreadPriority;
  60
  61 typedef struct _GThread         GThread;
  62 struct  _GThread
  63 {
  64   /*< private >*/
  65   GThreadFunc func;
  66   gpointer data;
  67   gboolean joinable;
  68   GThreadPriority priority;
  69 };
  70
  71 typedef struct _GMutex          GMutex;
  72 typedef struct _GCond           GCond;
  73 typedef struct _GPrivate        GPrivate;
  74 typedef struct _GStaticPrivate  GStaticPrivate;
  75
  76 #ifdef G_OS_WIN32
  77
  78 #define G_MUTEX_INIT { NULL }
  79 struct _GMutex
  80 {
  81     gpointer impl;
  82 };
  83
  84 #define G_COND_INIT { NULL }
  85 struct _GCond
  86 {
  87     gpointer impl;
  88 };
  89 #else
  90
  91 #include <pthread.h>
  92
  93 #define G_MUTEX_INIT { PTHREAD_MUTEX_INITIALIZER }
  94 struct _GMutex
  95 {
  96   pthread_mutex_t impl;
  97 };
  98
  99 #define G_COND_INIT { PTHREAD_COND_INITIALIZER }
 100 struct _GCond
 101 {
 102   pthread_cond_t impl;
 103 };
 104
 105 #endif
 106
 107 typedef struct _GThreadFunctions GThreadFunctions;
 108 struct _GThreadFunctions
 109 {
 110   GMutex*  (*mutex_new)           (void);
 111   void     (*mutex_lock)          (GMutex               *mutex);
 112   gboolean (*mutex_trylock)       (GMutex               *mutex);
 113   void     (*mutex_unlock)        (GMutex               *mutex);
 114   void     (*mutex_free)          (GMutex               *mutex);
 115   GCond*   (*cond_new)            (void);
 116   void     (*cond_signal)         (GCond                *cond);
 117   void     (*cond_broadcast)      (GCond                *cond);
 118   void     (*cond_wait)           (GCond                *cond,
 119                                    GMutex               *mutex);
 120   gboolean (*cond_timed_wait)     (GCond                *cond,
 121                                    GMutex               *mutex,
 122                                    GTimeVal             *end_time);
 123   void      (*cond_free)          (GCond                *cond);
 124   GPrivate* (*private_new)        (GDestroyNotify        destructor);
 125   gpointer  (*private_get)        (GPrivate             *private_key);
 126   void      (*private_set)        (GPrivate             *private_key,
 127                                    gpointer              data);
 128   void      (*thread_create)      (GThreadFunc           func,
 129                                    gpointer              data,
 130                                    gulong                stack_size,
 131                                    gboolean              joinable,
 132                                    gboolean              bound,
 133                                    GThreadPriority       priority,
 134                                    gpointer              thread,
 135                                    GError              **error);
 136   void      (*thread_yield)       (void);
 137   void      (*thread_join)        (gpointer              thread);
 138   void      (*thread_exit)        (void);
 139   void      (*thread_set_priority)(gpointer              thread,
 140                                    GThreadPriority       priority);
 141   void      (*thread_self)        (gpointer              thread);
 142   gboolean  (*thread_equal)       (gpointer              thread1,
 143                                    gpointer              thread2);
 144 };
 145
 146 GLIB_VAR GThreadFunctions       g_thread_functions_for_glib_use;
 147 GLIB_VAR gboolean               g_thread_use_default_impl;
 148 GLIB_VAR gboolean               g_threads_got_initialized;
 149
 150 #ifndef G_DISABLE_DEPRECATED
 151 GLIB_VAR guint64   (*g_thread_gettime) (void);
 152 #endif
 153
 154 /* initializes the mutex/cond/private implementation for glib, might
 155  * only be called once, and must not be called directly or indirectly
 156  * from another glib-function, e.g. as a callback.
 157  */
 158 void    g_thread_init   (GThreadFunctions       *vtable);
 159
 160 /* Checks if thread support is initialized.  Identical to the
 161  * g_thread_supported macro but provided for language bindings.
 162  */
 163 gboolean g_thread_get_initialized (void);
 164
 165 /* A random number to recognize debug calls to g_mutex_... */
 166 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
 167
 168 /* internal function for fallback static mutex implementation */
 169 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 170
 171 /* shorthands for conditional and unconditional function calls */
 172
 173 #define G_THREAD_UF(op, arglist)                                        \
 174     (*g_thread_functions_for_glib_use . op) arglist
 175 #define G_THREAD_CF(op, fail, arg)                                      \
 176     (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
 177 #define G_THREAD_ECF(op, fail, mutex, type)                             \
 178     (g_thread_supported () ?                                            \
 179       ((type(*)(GMutex*, const gulong, gchar const*))                   \
 180       (*g_thread_functions_for_glib_use . op))                          \
 181      (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
 182
 183
 184
 185 #if defined(G_THREADS_MANDATORY)
 186 #define g_thread_supported()     1
 187 #else
 188 #define g_thread_supported()    (g_threads_got_initialized)
 189 #endif
 190 #define g_private_new(destructor) G_THREAD_UF (private_new, (destructor))
 191 #define g_private_get(private_key) G_THREAD_CF (private_get, \
 192                                                 ((gpointer)private_key), \
 193                                                 (private_key))
 194 #define g_private_set(private_key, value) G_THREAD_CF (private_set, \
 195                                                        (void) (private_key = \
 196                                                         (GPrivate*) (value)), \
 197                                                        (private_key, value))
 198 #define g_thread_yield()              G_THREAD_CF (thread_yield, (void)0, ())
 199
 200 #define g_thread_create(func, data, joinable, error)                    \
 201   (g_thread_create_full (func, data, 0, joinable, FALSE,                \
 202                          G_THREAD_PRIORITY_NORMAL, error))
 203
 204 GThread* g_thread_create_full  (GThreadFunc            func,
 205                                 gpointer               data,
 206                                 gulong                 stack_size,
 207                                 gboolean               joinable,
 208                                 gboolean               bound,
 209                                 GThreadPriority        priority,
 210                                 GError               **error);
 211 GThread* g_thread_self         (void);
 212 void     g_thread_exit         (gpointer               retval);
 213 gpointer g_thread_join         (GThread               *thread);
 214
 215 void     g_thread_set_priority (GThread               *thread,
 216                                 GThreadPriority        priority);
 217
 218 #ifdef G_OS_WIN32
 219 typedef GMutex * GStaticMutex;
 220 #define G_STATIC_MUTEX_INIT NULL
 221 #define g_static_mutex_get_mutex g_static_mutex_get_mutex_impl
 222 #else /* G_OS_WIN32 */
 223 typedef struct {
 224   struct _GMutex *unused;
 225   GMutex mutex;
 226 } GStaticMutex;
 227 #define G_STATIC_MUTEX_INIT { NULL, G_MUTEX_INIT }
 228 #define g_static_mutex_get_mutex(s) (&(s)->mutex)
 229 #endif /* G_OS_WIN32 */
 230
 231 #define g_static_mutex_lock(mutex) \
 232     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 233 #define g_static_mutex_trylock(mutex) \
 234     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 235 #define g_static_mutex_unlock(mutex) \
 236     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 237 void g_static_mutex_init (GStaticMutex *mutex);
 238 void g_static_mutex_free (GStaticMutex *mutex);
 239
 240 struct _GStaticPrivate
 241 {
 242   /*< private >*/
 243   guint index;
 244 };
 245 #define G_STATIC_PRIVATE_INIT { 0 }
 246 void     g_static_private_init           (GStaticPrivate   *private_key);
 247 gpointer g_static_private_get            (GStaticPrivate   *private_key);
 248 void     g_static_private_set            (GStaticPrivate   *private_key,
 249                                           gpointer          data,
 250                                           GDestroyNotify    notify);
 251 void     g_static_private_free           (GStaticPrivate   *private_key);
 252
 253 typedef struct _GStaticRecMutex GStaticRecMutex;
 254 struct _GStaticRecMutex
 255 {
 256   /*< private >*/
 257   GStaticMutex mutex;
 258   guint depth;
 259   GSystemThread owner;
 260 };
 261
 262 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT, 0, {{0, 0, 0, 0}} }
 263 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 264 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 265 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 266 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 267 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 268                                          guint            depth);
 269 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 270 void     g_static_rec_mutex_free        (GStaticRecMutex *mutex);
 271
 272 typedef struct _GStaticRWLock GStaticRWLock;
 273 struct _GStaticRWLock
 274 {
 275   /*< private >*/
 276   GStaticMutex mutex;
 277   GCond *read_cond;
 278   GCond *write_cond;
 279   guint read_counter;
 280   gboolean have_writer;
 281   guint want_to_read;
 282   guint want_to_write;
 283 };
 284
 285 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, 0, 0 }
 286
 287 void      g_static_rw_lock_init           (GStaticRWLock* lock);
 288 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 289 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 290 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 291 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 292 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 293 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 294 void      g_static_rw_lock_free           (GStaticRWLock* lock);
 295
 296 void      g_thread_foreach                (GFunc          thread_func,
 297                                            gpointer       user_data);
 298
 299 typedef enum
 300 {
 301   G_ONCE_STATUS_NOTCALLED,
 302   G_ONCE_STATUS_PROGRESS,
 303   G_ONCE_STATUS_READY
 304 } GOnceStatus;
 305
 306 typedef struct _GOnce GOnce;
 307 struct _GOnce
 308 {
 309   volatile GOnceStatus status;
 310   volatile gpointer retval;
 311 };
 312
 313 #define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
 314
 315 gpointer g_once_impl (GOnce *once, GThreadFunc func, gpointer arg);
 316
 317 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 318 # define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
 319 #else /* !G_ATOMIC_OP_MEMORY_BARRIER_NEEDED*/
 320 # define g_once(once, func, arg) \
 321   (((once)->status == G_ONCE_STATUS_READY) ? \
 322    (once)->retval : \
 323    g_once_impl ((once), (func), (arg)))
 324 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 325
 326 /* initialize-once guards, keyed by value_location */
 327 G_INLINE_FUNC gboolean  g_once_init_enter       (volatile gsize *value_location);
 328 gboolean                g_once_init_enter_impl  (volatile gsize *value_location);
 329 void                    g_once_init_leave       (volatile gsize *value_location,
 330                                                  gsize           initialization_value);
 331 #if defined (G_CAN_INLINE) || defined (__G_THREAD_C__)
 332 G_INLINE_FUNC gboolean
 333 g_once_init_enter (volatile gsize *value_location)
 334 {
 335   if G_LIKELY ((gpointer) g_atomic_pointer_get (value_location) != NULL)
 336     return FALSE;
 337   else
 338     return g_once_init_enter_impl (value_location);
 339 }
 340 #endif /* G_CAN_INLINE || __G_THREAD_C__ */
 341
 342 /* these are some convenience macros that expand to nothing if GLib
 343  * was configured with --disable-threads. for using StaticMutexes,
 344  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 345  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 346  * declare such an globally defined lock. name is a unique identifier
 347  * for the protected varibale or code portion. locking, testing and
 348  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 349  * G_TRYLOCK() respectively.
 350  */
 351 extern void glib_dummy_decl (void);
 352 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 353 #define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 354 #define G_LOCK_DEFINE(name)           \
 355   GMutex G_LOCK_NAME (name) = G_MUTEX_INIT
 356 #define G_LOCK_EXTERN(name)           extern GMutex G_LOCK_NAME (name)
 357
 358 #ifdef G_DEBUG_LOCKS
 359 #  define G_LOCK(name)                G_STMT_START{             \
 360       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 361              "file %s: line %d (%s): locking: %s ",             \
 362              __FILE__,        __LINE__, G_STRFUNC,              \
 363              #name);                                            \
 364       g_mutex_lock (&G_LOCK_NAME (name));                       \
 365    }G_STMT_END
 366 #  define G_UNLOCK(name)              G_STMT_START{             \
 367       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 368              "file %s: line %d (%s): unlocking: %s ",           \
 369              __FILE__,        __LINE__, G_STRFUNC,              \
 370              #name);                                            \
 371      g_mutex_unlock (&G_LOCK_NAME (name));                      \
 372    }G_STMT_END
 373 #  define G_TRYLOCK(name)                                       \
 374       (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 375              "file %s: line %d (%s): try locking: %s ",         \
 376              __FILE__,        __LINE__, G_STRFUNC,              \
 377              #name), g_mutex_trylock (&G_LOCK_NAME (name)))
 378 #else  /* !G_DEBUG_LOCKS */
 379 #  define G_LOCK(name) g_mutex_lock       (&G_LOCK_NAME (name))
 380 #  define G_UNLOCK(name) g_mutex_unlock   (&G_LOCK_NAME (name))
 381 #  define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
 382 #endif /* !G_DEBUG_LOCKS */
 383
 384
 385 void                    g_mutex_init                                    (GMutex         *mutex);
 386 void                    g_mutex_clear                                   (GMutex         *mutex);
 387
 388 void                    g_mutex_lock                                    (GMutex         *mutex);
 389 void                    g_mutex_unlock                                  (GMutex         *mutex);
 390 gboolean                g_mutex_trylock                                 (GMutex         *mutex);
 391
 392 void                    g_cond_init                                     (GCond          *cond);
 393 void                    g_cond_clear                                    (GCond          *cond);
 394
 395 void                    g_cond_wait                                     (GCond          *cond,
 396                                                                          GMutex         *mutex);
 397 void                    g_cond_signal                                   (GCond          *cond);
 398 void                    g_cond_broadcast                                (GCond          *cond);
 399 gboolean                g_cond_timed_wait                               (GCond          *cond,
 400                                                                          GMutex         *mutex,
 401                                                                          GTimeVal       *timeval);
 402 gboolean                g_cond_timedwait                                (GCond          *cond,
 403                                                                          GMutex         *mutex,
 404                                                                          gint64          abs_time);
 405
 406 GMutex *                g_mutex_new                                     (void);
 407 void                    g_mutex_free                                    (GMutex         *mutex);
 408 GCond *                 g_cond_new                                      (void);
 409 void                    g_cond_free                                     (GCond          *cond);
 410
 411 G_END_DECLS
 412
 413 #endif /* __G_THREAD_H__ */