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 struct _GThread         GThread;
  54
  55 typedef struct _GMutex          GMutex;
  56 typedef struct _GCond           GCond;
  57 typedef struct _GPrivate        GPrivate;
  58 typedef struct _GStaticPrivate  GStaticPrivate;
  59
  60 #ifdef G_OS_WIN32
  61
  62 #define G_MUTEX_INIT { NULL }
  63 struct _GMutex
  64 {
  65     gpointer impl;
  66 };
  67
  68 #define G_COND_INIT { NULL }
  69 struct _GCond
  70 {
  71     gpointer impl;
  72 };
  73 #else
  74
  75 #include <pthread.h>
  76
  77 #define G_MUTEX_INIT { PTHREAD_MUTEX_INITIALIZER }
  78 struct _GMutex
  79 {
  80   pthread_mutex_t impl;
  81 };
  82
  83 #define G_COND_INIT { PTHREAD_COND_INITIALIZER }
  84 struct _GCond
  85 {
  86   pthread_cond_t impl;
  87 };
  88
  89 #endif
  90
  91 /* initializes the mutex/cond/private implementation for glib, might
  92  * only be called once, and must not be called directly or indirectly
  93  * from another glib-function, e.g. as a callback.
  94  */
  95 void    g_thread_init   (gpointer vtable);
  96
  97 /* Checks if thread support is initialized.  Identical to the
  98  * g_thread_supported macro but provided for language bindings.
  99  */
 100 gboolean g_thread_get_initialized (void);
 101
 102 GLIB_VAR gboolean               g_threads_got_initialized;
 103
 104 /* internal function for fallback static mutex implementation */
 105 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 106
 107 #if defined(G_THREADS_MANDATORY)
 108 #define g_thread_supported()     1
 109 #else
 110 #define g_thread_supported()    (g_threads_got_initialized)
 111 #endif
 112
 113 GThread *g_thread_create                 (GThreadFunc   func,
 114                                           gpointer      data,
 115                                           gboolean      joinable,
 116                                           GError      **error);
 117
 118 GThread *g_thread_create_with_stack_size (GThreadFunc   func,
 119                                           gpointer      data,
 120                                           gboolean      joinable,
 121                                           gsize         stack_size,
 122                                           GError      **error);
 123
 124 GThread* g_thread_self                   (void);
 125 void     g_thread_exit                   (gpointer      retval);
 126 gpointer g_thread_join                   (GThread      *thread);
 127 void     g_thread_yield                  (void);
 128
 129 void     g_thread_foreach                (GFunc         thread_func,
 130                                           gpointer      user_data);
 131
 132 #ifdef G_OS_WIN32
 133 typedef GMutex * GStaticMutex;
 134 #define G_STATIC_MUTEX_INIT NULL
 135 #define g_static_mutex_get_mutex g_static_mutex_get_mutex_impl
 136 #else /* G_OS_WIN32 */
 137 typedef struct {
 138   struct _GMutex *unused;
 139   GMutex mutex;
 140 } GStaticMutex;
 141 #define G_STATIC_MUTEX_INIT { NULL, G_MUTEX_INIT }
 142 #define g_static_mutex_get_mutex(s) (&(s)->mutex)
 143 #endif /* G_OS_WIN32 */
 144
 145 #define g_static_mutex_lock(mutex) \
 146     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 147 #define g_static_mutex_trylock(mutex) \
 148     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 149 #define g_static_mutex_unlock(mutex) \
 150     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 151 void g_static_mutex_init (GStaticMutex *mutex);
 152 void g_static_mutex_free (GStaticMutex *mutex);
 153
 154 struct _GStaticPrivate
 155 {
 156   /*< private >*/
 157   guint index;
 158 };
 159 #define G_STATIC_PRIVATE_INIT { 0 }
 160 void     g_static_private_init           (GStaticPrivate   *private_key);
 161 gpointer g_static_private_get            (GStaticPrivate   *private_key);
 162 void     g_static_private_set            (GStaticPrivate   *private_key,
 163                                           gpointer          data,
 164                                           GDestroyNotify    notify);
 165 void     g_static_private_free           (GStaticPrivate   *private_key);
 166
 167 typedef struct _GStaticRecMutex GStaticRecMutex;
 168 struct _GStaticRecMutex
 169 {
 170   /*< private >*/
 171   GStaticMutex mutex;
 172   guint depth;
 173   GSystemThread owner;
 174 };
 175
 176 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT, 0, {{0, 0, 0, 0}} }
 177 void     g_static_rec_mutex_init        (GStaticRecMutex *mutex);
 178 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 179 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 180 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 181 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 182                                          guint            depth);
 183 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 184 void     g_static_rec_mutex_free        (GStaticRecMutex *mutex);
 185
 186 typedef struct _GStaticRWLock GStaticRWLock;
 187 struct _GStaticRWLock
 188 {
 189   /*< private >*/
 190   GStaticMutex mutex;
 191   GCond *read_cond;
 192   GCond *write_cond;
 193   guint read_counter;
 194   gboolean have_writer;
 195   guint want_to_read;
 196   guint want_to_write;
 197 };
 198
 199 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, 0, 0 }
 200
 201 void      g_static_rw_lock_init           (GStaticRWLock* lock);
 202 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 203 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 204 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 205 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 206 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 207 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 208 void      g_static_rw_lock_free           (GStaticRWLock* lock);
 209
 210 typedef enum
 211 {
 212   G_ONCE_STATUS_NOTCALLED,
 213   G_ONCE_STATUS_PROGRESS,
 214   G_ONCE_STATUS_READY
 215 } GOnceStatus;
 216
 217 typedef struct _GOnce GOnce;
 218 struct _GOnce
 219 {
 220   volatile GOnceStatus status;
 221   volatile gpointer retval;
 222 };
 223
 224 #define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
 225
 226 gpointer g_once_impl (GOnce *once, GThreadFunc func, gpointer arg);
 227
 228 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 229 # define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
 230 #else /* !G_ATOMIC_OP_MEMORY_BARRIER_NEEDED*/
 231 # define g_once(once, func, arg) \
 232   (((once)->status == G_ONCE_STATUS_READY) ? \
 233    (once)->retval : \
 234    g_once_impl ((once), (func), (arg)))
 235 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 236
 237 /* initialize-once guards, keyed by value_location */
 238 G_INLINE_FUNC gboolean  g_once_init_enter       (volatile gsize *value_location);
 239 gboolean                g_once_init_enter_impl  (volatile gsize *value_location);
 240 void                    g_once_init_leave       (volatile gsize *value_location,
 241                                                  gsize           initialization_value);
 242 #if defined (G_CAN_INLINE) || defined (__G_THREAD_C__)
 243 G_INLINE_FUNC gboolean
 244 g_once_init_enter (volatile gsize *value_location)
 245 {
 246   if G_LIKELY ((gpointer) g_atomic_pointer_get (value_location) != NULL)
 247     return FALSE;
 248   else
 249     return g_once_init_enter_impl (value_location);
 250 }
 251 #endif /* G_CAN_INLINE || __G_THREAD_C__ */
 252
 253 /* these are some convenience macros that expand to nothing if GLib
 254  * was configured with --disable-threads. for using StaticMutexes,
 255  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 256  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 257  * declare such an globally defined lock. name is a unique identifier
 258  * for the protected varibale or code portion. locking, testing and
 259  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 260  * G_TRYLOCK() respectively.
 261  */
 262 extern void glib_dummy_decl (void);
 263 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 264 #define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 265 #define G_LOCK_DEFINE(name)           \
 266   GMutex G_LOCK_NAME (name) = G_MUTEX_INIT
 267 #define G_LOCK_EXTERN(name)           extern GMutex G_LOCK_NAME (name)
 268
 269 #ifdef G_DEBUG_LOCKS
 270 #  define G_LOCK(name)                G_STMT_START{             \
 271       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 272              "file %s: line %d (%s): locking: %s ",             \
 273              __FILE__,        __LINE__, G_STRFUNC,              \
 274              #name);                                            \
 275       g_mutex_lock (&G_LOCK_NAME (name));                       \
 276    }G_STMT_END
 277 #  define G_UNLOCK(name)              G_STMT_START{             \
 278       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 279              "file %s: line %d (%s): unlocking: %s ",           \
 280              __FILE__,        __LINE__, G_STRFUNC,              \
 281              #name);                                            \
 282      g_mutex_unlock (&G_LOCK_NAME (name));                      \
 283    }G_STMT_END
 284 #  define G_TRYLOCK(name)                                       \
 285       (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 286              "file %s: line %d (%s): try locking: %s ",         \
 287              __FILE__,        __LINE__, G_STRFUNC,              \
 288              #name), g_mutex_trylock (&G_LOCK_NAME (name)))
 289 #else  /* !G_DEBUG_LOCKS */
 290 #  define G_LOCK(name) g_mutex_lock       (&G_LOCK_NAME (name))
 291 #  define G_UNLOCK(name) g_mutex_unlock   (&G_LOCK_NAME (name))
 292 #  define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
 293 #endif /* !G_DEBUG_LOCKS */
 294
 295
 296 GMutex *                g_mutex_new                                     (void);
 297 void                    g_mutex_free                                    (GMutex         *mutex);
 298 void                    g_mutex_init                                    (GMutex         *mutex);
 299 void                    g_mutex_clear                                   (GMutex         *mutex);
 300
 301 void                    g_mutex_lock                                    (GMutex         *mutex);
 302 void                    g_mutex_unlock                                  (GMutex         *mutex);
 303 gboolean                g_mutex_trylock                                 (GMutex         *mutex);
 304
 305 GCond *                 g_cond_new                                      (void);
 306 void                    g_cond_free                                     (GCond          *cond);
 307 void                    g_cond_init                                     (GCond          *cond);
 308 void                    g_cond_clear                                    (GCond          *cond);
 309
 310 void                    g_cond_wait                                     (GCond          *cond,
 311                                                                          GMutex         *mutex);
 312 void                    g_cond_signal                                   (GCond          *cond);
 313 void                    g_cond_broadcast                                (GCond          *cond);
 314 gboolean                g_cond_timed_wait                               (GCond          *cond,
 315                                                                          GMutex         *mutex,
 316                                                                          GTimeVal       *timeval);
 317 gboolean                g_cond_timedwait                                (GCond          *cond,
 318                                                                          GMutex         *mutex,
 319                                                                          gint64          abs_time);
 320
 321 GPrivate *              g_private_new                                   (GDestroyNotify  notify);
 322 gpointer                g_private_get                                   (GPrivate       *key);
 323 void                    g_private_set                                   (GPrivate       *key,
 324                                                                          gpointer        value);
 325
 326 G_END_DECLS
 327
 328 #endif /* __G_THREAD_H__ */