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 modify
   5  * it under the terms of the GNU Lesser General Public License as
   6  * published by the Free Software Foundation; either version 2 of the
   7  * licence, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * 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, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 /*
  19  * Modified by the GLib Team and others 1997-2000.  See the AUTHORS
  20  * file for a list of people on the GLib Team.  See the ChangeLog
  21  * files for a list of changes.  These files are distributed with
  22  * GLib at ftp://ftp.gtk.org/pub/gtk/.
  23  */
  24
  25 #ifndef __G_THREAD_H__
  26 #define __G_THREAD_H__
  27
  28 #if !defined (__GLIB_H_INSIDE__) && !defined (GLIB_COMPILATION)
  29 #error "Only <glib.h> can be included directly."
  30 #endif
  31
  32 #include <glib/gatomic.h>
  33 #include <glib/gerror.h>
  34 #include <glib/gutils.h>
  35
  36 G_BEGIN_DECLS
  37
  38 #define G_THREAD_ERROR g_thread_error_quark ()
  39 GLIB_AVAILABLE_IN_ALL
  40 GQuark g_thread_error_quark (void);
  41
  42 typedef enum
  43 {
  44   G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
  45 } GThreadError;
  46
  47 typedef gpointer (*GThreadFunc) (gpointer data);
  48
  49 typedef struct _GThread         GThread;
  50
  51 typedef union  _GMutex          GMutex;
  52 typedef struct _GRecMutex       GRecMutex;
  53 typedef struct _GRWLock         GRWLock;
  54 typedef struct _GCond           GCond;
  55 typedef struct _GPrivate        GPrivate;
  56 typedef struct _GOnce           GOnce;
  57
  58 union _GMutex
  59 {
  60   /*< private >*/
  61   gpointer p;
  62   guint i[2];
  63 };
  64
  65 struct _GRWLock
  66 {
  67   /*< private >*/
  68   gpointer p;
  69   guint i[2];
  70 };
  71
  72 struct _GCond
  73 {
  74   /*< private >*/
  75   gpointer p;
  76   guint i[2];
  77 };
  78
  79 struct _GRecMutex
  80 {
  81   /*< private >*/
  82   gpointer p;
  83   guint i[2];
  84 };
  85
  86 #define G_PRIVATE_INIT(notify) { NULL, (notify), { NULL, NULL } }
  87 struct _GPrivate
  88 {
  89   /*< private >*/
  90   gpointer       p;
  91   GDestroyNotify notify;
  92   gpointer future[2];
  93 };
  94
  95 typedef enum
  96 {
  97   G_ONCE_STATUS_NOTCALLED,
  98   G_ONCE_STATUS_PROGRESS,
  99   G_ONCE_STATUS_READY
 100 } GOnceStatus;
 101
 102 #define G_ONCE_INIT { G_ONCE_STATUS_NOTCALLED, NULL }
 103 struct _GOnce
 104 {
 105   volatile GOnceStatus status;
 106   volatile gpointer retval;
 107 };
 108
 109 #define G_LOCK_NAME(name)             g__ ## name ## _lock
 110 #define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 111 #define G_LOCK_DEFINE(name)           GMutex G_LOCK_NAME (name)
 112 #define G_LOCK_EXTERN(name)           extern GMutex G_LOCK_NAME (name)
 113
 114 #ifdef G_DEBUG_LOCKS
 115 #  define G_LOCK(name)                G_STMT_START{             \
 116       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 117              "file %s: line %d (%s): locking: %s ",             \
 118              __FILE__,        __LINE__, G_STRFUNC,              \
 119              #name);                                            \
 120       g_mutex_lock (&G_LOCK_NAME (name));                       \
 121    }G_STMT_END
 122 #  define G_UNLOCK(name)              G_STMT_START{             \
 123       g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 124              "file %s: line %d (%s): unlocking: %s ",           \
 125              __FILE__,        __LINE__, G_STRFUNC,              \
 126              #name);                                            \
 127      g_mutex_unlock (&G_LOCK_NAME (name));                      \
 128    }G_STMT_END
 129 #  define G_TRYLOCK(name)                                       \
 130       (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 131              "file %s: line %d (%s): try locking: %s ",         \
 132              __FILE__,        __LINE__, G_STRFUNC,              \
 133              #name), g_mutex_trylock (&G_LOCK_NAME (name)))
 134 #else  /* !G_DEBUG_LOCKS */
 135 #  define G_LOCK(name) g_mutex_lock       (&G_LOCK_NAME (name))
 136 #  define G_UNLOCK(name) g_mutex_unlock   (&G_LOCK_NAME (name))
 137 #  define G_TRYLOCK(name) g_mutex_trylock (&G_LOCK_NAME (name))
 138 #endif /* !G_DEBUG_LOCKS */
 139
 140 GLIB_AVAILABLE_IN_2_32
 141 GThread *       g_thread_ref                    (GThread        *thread);
 142 GLIB_AVAILABLE_IN_2_32
 143 void            g_thread_unref                  (GThread        *thread);
 144 GLIB_AVAILABLE_IN_2_32
 145 GThread *       g_thread_new                    (const gchar    *name,
 146                                                  GThreadFunc     func,
 147                                                  gpointer        data);
 148 GLIB_AVAILABLE_IN_2_32
 149 GThread *       g_thread_try_new                (const gchar    *name,
 150                                                  GThreadFunc     func,
 151                                                  gpointer        data,
 152                                                  GError        **error);
 153 GLIB_AVAILABLE_IN_ALL
 154 GThread *       g_thread_self                   (void);
 155 GLIB_AVAILABLE_IN_ALL
 156 void            g_thread_exit                   (gpointer        retval);
 157 GLIB_AVAILABLE_IN_ALL
 158 gpointer        g_thread_join                   (GThread        *thread);
 159 GLIB_AVAILABLE_IN_ALL
 160 void            g_thread_yield                  (void);
 161
 162
 163 GLIB_AVAILABLE_IN_2_32
 164 void            g_mutex_init                    (GMutex         *mutex);
 165 GLIB_AVAILABLE_IN_2_32
 166 void            g_mutex_clear                   (GMutex         *mutex);
 167 GLIB_AVAILABLE_IN_ALL
 168 void            g_mutex_lock                    (GMutex         *mutex);
 169 GLIB_AVAILABLE_IN_ALL
 170 gboolean        g_mutex_trylock                 (GMutex         *mutex);
 171 GLIB_AVAILABLE_IN_ALL
 172 void            g_mutex_unlock                  (GMutex         *mutex);
 173
 174 GLIB_AVAILABLE_IN_2_32
 175 void            g_rw_lock_init                  (GRWLock        *rw_lock);
 176 GLIB_AVAILABLE_IN_2_32
 177 void            g_rw_lock_clear                 (GRWLock        *rw_lock);
 178 GLIB_AVAILABLE_IN_2_32
 179 void            g_rw_lock_writer_lock           (GRWLock        *rw_lock);
 180 GLIB_AVAILABLE_IN_2_32
 181 gboolean        g_rw_lock_writer_trylock        (GRWLock        *rw_lock);
 182 GLIB_AVAILABLE_IN_2_32
 183 void            g_rw_lock_writer_unlock         (GRWLock        *rw_lock);
 184 GLIB_AVAILABLE_IN_2_32
 185 void            g_rw_lock_reader_lock           (GRWLock        *rw_lock);
 186 GLIB_AVAILABLE_IN_2_32
 187 gboolean        g_rw_lock_reader_trylock        (GRWLock        *rw_lock);
 188 GLIB_AVAILABLE_IN_2_32
 189 void            g_rw_lock_reader_unlock         (GRWLock        *rw_lock);
 190
 191 GLIB_AVAILABLE_IN_2_32
 192 void            g_rec_mutex_init                (GRecMutex      *rec_mutex);
 193 GLIB_AVAILABLE_IN_2_32
 194 void            g_rec_mutex_clear               (GRecMutex      *rec_mutex);
 195 GLIB_AVAILABLE_IN_2_32
 196 void            g_rec_mutex_lock                (GRecMutex      *rec_mutex);
 197 GLIB_AVAILABLE_IN_2_32
 198 gboolean        g_rec_mutex_trylock             (GRecMutex      *rec_mutex);
 199 GLIB_AVAILABLE_IN_2_32
 200 void            g_rec_mutex_unlock              (GRecMutex      *rec_mutex);
 201
 202 GLIB_AVAILABLE_IN_2_32
 203 void            g_cond_init                     (GCond          *cond);
 204 GLIB_AVAILABLE_IN_2_32
 205 void            g_cond_clear                    (GCond          *cond);
 206 GLIB_AVAILABLE_IN_ALL
 207 void            g_cond_wait                     (GCond          *cond,
 208                                                  GMutex         *mutex);
 209 GLIB_AVAILABLE_IN_ALL
 210 void            g_cond_signal                   (GCond          *cond);
 211 GLIB_AVAILABLE_IN_ALL
 212 void            g_cond_broadcast                (GCond          *cond);
 213 GLIB_AVAILABLE_IN_2_32
 214 gboolean        g_cond_wait_until               (GCond          *cond,
 215                                                  GMutex         *mutex,
 216                                                  gint64          end_time);
 217
 218 GLIB_AVAILABLE_IN_ALL
 219 gpointer        g_private_get                   (GPrivate       *key);
 220 GLIB_AVAILABLE_IN_ALL
 221 void            g_private_set                   (GPrivate       *key,
 222                                                  gpointer        value);
 223 GLIB_AVAILABLE_IN_2_32
 224 void            g_private_replace               (GPrivate       *key,
 225                                                  gpointer        value);
 226
 227 GLIB_AVAILABLE_IN_ALL
 228 gpointer        g_once_impl                     (GOnce          *once,
 229                                                  GThreadFunc     func,
 230                                                  gpointer        arg);
 231 GLIB_AVAILABLE_IN_ALL
 232 gboolean        g_once_init_enter               (volatile void  *location);
 233 GLIB_AVAILABLE_IN_ALL
 234 void            g_once_init_leave               (volatile void  *location,
 235                                                  gsize           result);
 236
 237 #ifdef G_ATOMIC_OP_MEMORY_BARRIER_NEEDED
 238 # define g_once(once, func, arg) g_once_impl ((once), (func), (arg))
 239 #else /* !G_ATOMIC_OP_MEMORY_BARRIER_NEEDED*/
 240 # define g_once(once, func, arg) \
 241   (((once)->status == G_ONCE_STATUS_READY) ? \
 242    (once)->retval : \
 243    g_once_impl ((once), (func), (arg)))
 244 #endif /* G_ATOMIC_OP_MEMORY_BARRIER_NEEDED */
 245
 246 #ifdef __GNUC__
 247 # define g_once_init_enter(location) \
 248   (G_GNUC_EXTENSION ({                                               \
 249     G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer));       \
 250     (void) (0 ? (gpointer) *(location) : 0);                         \
 251     (!g_atomic_pointer_get (location) &&                             \
 252      g_once_init_enter (location));                                  \
 253   }))
 254 # define g_once_init_leave(location, result) \
 255   (G_GNUC_EXTENSION ({                                               \
 256     G_STATIC_ASSERT (sizeof *(location) == sizeof (gpointer));       \
 257     (void) (0 ? *(location) = (result) : 0);                         \
 258     g_once_init_leave ((location), (gsize) (result));                \
 259   }))
 260 #else
 261 # define g_once_init_enter(location) \
 262   (g_once_init_enter((location)))
 263 # define g_once_init_leave(location, result) \
 264   (g_once_init_leave((location), (gsize) (result)))
 265 #endif
 266
 267 GLIB_AVAILABLE_IN_2_36
 268 guint          g_get_num_processors (void);
 269
 270 /**
 271  * GMutexLocker:
 272  *
 273  * Opaque type. See g_mutex_locker_new() for details.
 274  * Since: 2.44
 275  */
 276 typedef void GMutexLocker;
 277
 278 /**
 279  * g_mutex_locker_new:
 280  * @mutex: a mutex to lock
 281  *
 282  * Lock @mutex and return a new #GMutexLocker. Unlock with
 283  * g_mutex_locker_free(). Using g_mutex_unlock() on @mutex
 284  * while a #GMutexLocker exists can lead to undefined behaviour.
 285  *
 286  * This is intended to be used with g_autoptr().  Note that g_autoptr()
 287  * is only available when using GCC or clang, so the following example
 288  * will only work with those compilers:
 289  * |[
 290  * typedef struct
 291  * {
 292  *   ...
 293  *   GMutex mutex;
 294  *   ...
 295  * } MyObject;
 296  *
 297  * static void
 298  * my_object_do_stuff (MyObject *self)
 299  * {
 300  *   g_autoptr(GMutexLocker) locker = g_mutex_locker_new (&self->mutex);
 301  *
 302  *   // Code with mutex locked here
 303  *
 304  *   if (cond)
 305  *     // No need to unlock
 306  *     return;
 307  *
 308  *   // Optionally early unlock
 309  *   g_clear_pointer (&locker, g_mutex_locker_free);
 310  *
 311  *   // Code with mutex unlocked here
 312  * }
 313  * ]|
 314  *
 315  * Returns: a #GMutexLocker
 316  * Since: 2.44
 317  */
 318 static inline GMutexLocker *
 319 g_mutex_locker_new (GMutex *mutex)
 320 {
 321   g_mutex_lock (mutex);
 322   return (GMutexLocker *) mutex;
 323 }
 324
 325 /**
 326  * g_mutex_locker_free:
 327  * @locker: a GMutexLocker
 328  *
 329  * Unlock @locker's mutex. See g_mutex_locker_new() for details.
 330  *
 331  * Since: 2.44
 332  */
 333 static inline void
 334 g_mutex_locker_free (GMutexLocker *locker)
 335 {
 336   g_mutex_unlock ((GMutex *) locker);
 337 }
 338
 339 G_END_DECLS
 340
 341 #endif /* __G_THREAD_H__ */