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 <gerror.h>
  31 #include <gmain.h>
  32
  33 G_BEGIN_DECLS
  34
  35 #ifndef GLIB_VAR
  36 #  ifdef G_OS_WIN32
  37 #    ifdef GLIB_COMPILATION
  38 #      define GLIB_VAR __declspec(dllexport)
  39 #    else /* !GLIB_COMPILATION */
  40 #      define GLIB_VAR extern __declspec(dllimport)
  41 #    endif /* !GLIB_COMPILATION */
  42 #  else /* !G_OS_WIN32 */
  43 #    define GLIB_VAR extern
  44 #  endif /* !G_OS_WIN32 */
  45 #endif /* GLIB_VAR */
  46
  47 /* GLib Thread support
  48  */
  49
  50 extern GQuark g_thread_error_quark();
  51 #define G_THREAD_ERROR g_thread_error_quark()
  52
  53 typedef enum
  54 {
  55   G_THREAD_ERROR_AGAIN /* Resource temporarily unavailable */
  56 } GThreadError;
  57
  58 typedef void            (*GThreadFunc)          (gpointer       value);
  59
  60 typedef enum
  61 {
  62   G_THREAD_PRIORITY_LOW,
  63   G_THREAD_PRIORITY_NORMAL,
  64   G_THREAD_PRIORITY_HIGH,
  65   G_THREAD_PRIORITY_URGENT
  66 } GThreadPriority;
  67
  68 typedef struct _GThread         GThread;
  69 struct  _GThread
  70 {
  71   GThreadPriority priority;
  72   gboolean bound;
  73   gboolean joinable;
  74 };
  75
  76 typedef struct _GMutex          GMutex;
  77 typedef struct _GCond           GCond;
  78 typedef struct _GPrivate        GPrivate;
  79 typedef struct _GStaticPrivate  GStaticPrivate;
  80
  81 typedef struct _GThreadFunctions GThreadFunctions;
  82 struct _GThreadFunctions
  83 {
  84   GMutex*  (*mutex_new)           (void);
  85   void     (*mutex_lock)          (GMutex               *mutex);
  86   gboolean (*mutex_trylock)       (GMutex               *mutex);
  87   void     (*mutex_unlock)        (GMutex               *mutex);
  88   void     (*mutex_free)          (GMutex               *mutex);
  89   GCond*   (*cond_new)            (void);
  90   void     (*cond_signal)         (GCond                *cond);
  91   void     (*cond_broadcast)      (GCond                *cond);
  92   void     (*cond_wait)           (GCond                *cond,
  93                                    GMutex               *mutex);
  94   gboolean (*cond_timed_wait)     (GCond                *cond,
  95                                    GMutex               *mutex,
  96                                    GTimeVal             *end_time);
  97   void      (*cond_free)          (GCond                *cond);
  98   GPrivate* (*private_new)        (GDestroyNotify        destructor);
  99   gpointer  (*private_get)        (GPrivate             *private_key);
 100   void      (*private_set)        (GPrivate             *private_key,
 101                                    gpointer              data);
 102   void      (*thread_create)      (GThreadFunc           thread_func,
 103                                    gpointer              arg,
 104                                    gulong                stack_size,
 105                                    gboolean              joinable,
 106                                    gboolean              bound,
 107                                    GThreadPriority       priority,
 108                                    gpointer              thread,
 109                                    GError              **error);
 110   void      (*thread_yield)       (void);
 111   void      (*thread_join)        (gpointer              thread);
 112   void      (*thread_exit)        (void);
 113   void      (*thread_set_priority)(gpointer              thread,
 114                                    GThreadPriority       priority);
 115   void      (*thread_self)        (gpointer              thread);
 116 };
 117
 118 GLIB_VAR GThreadFunctions       g_thread_functions_for_glib_use;
 119 GLIB_VAR gboolean               g_thread_use_default_impl;
 120 GLIB_VAR gboolean               g_threads_got_initialized;
 121
 122 /* initializes the mutex/cond/private implementation for glib, might
 123  * only be called once, and must not be called directly or indirectly
 124  * from another glib-function, e.g. as a callback.
 125  */
 126 void    g_thread_init   (GThreadFunctions       *vtable);
 127
 128 /* Errorcheck mutexes. If you define G_ERRORCHECK_MUTEXES, then all
 129  * mutexes will check for re-locking and re-unlocking */
 130
 131 /* Initialize thread system with errorcheck mutexes. vtable must be
 132  * NULL. Do not call directly. Use #define G_ERRORCHECK_MUTEXES
 133  * instead.
 134  */
 135 void    g_thread_init_with_errorcheck_mutexes (GThreadFunctions* vtable);
 136
 137 /* A random number to recognize debug calls to g_mutex_... */
 138 #define G_MUTEX_DEBUG_MAGIC 0xf8e18ad7
 139
 140 #ifdef G_ERRORCHECK_MUTEXES
 141 #define g_thread_init(vtable) g_thread_init_with_errorcheck_mutexes (vtable)
 142 #endif
 143
 144 /* internal function for fallback static mutex implementation */
 145 GMutex* g_static_mutex_get_mutex_impl   (GMutex **mutex);
 146
 147 /* shorthands for conditional and unconditional function calls */
 148
 149 #define G_THREAD_UF(op, arglist)                                        \
 150     (*g_thread_functions_for_glib_use . op) arglist
 151 #define G_THREAD_CF(op, fail, arg)                                      \
 152     (g_thread_supported () ? G_THREAD_UF (op, arg) : (fail))
 153 #define G_THREAD_ECF(op, fail, mutex, type)                             \
 154     (g_thread_supported () ? ((type(*)(GMutex*, gulong, gchar*))        \
 155       (*g_thread_functions_for_glib_use . op))                          \
 156      (mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (fail))
 157
 158 #ifndef G_ERRORCHECK_MUTEXES
 159 # define g_mutex_lock(mutex)                                            \
 160     G_THREAD_CF (mutex_lock,     (void)0, (mutex))
 161 # define g_mutex_trylock(mutex)                                         \
 162     G_THREAD_CF (mutex_trylock,  TRUE,    (mutex))
 163 # define g_mutex_unlock(mutex)                                          \
 164     G_THREAD_CF (mutex_unlock,   (void)0, (mutex))
 165 # define g_cond_wait(cond, mutex)                                       \
 166     G_THREAD_CF (cond_wait,      (void)0, (cond, mutex))
 167 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 168     G_THREAD_CF (cond_timed_wait, TRUE,   (cond, mutex, abs_time))
 169 #else /* G_ERRORCHECK_MUTEXES */
 170 # define g_mutex_lock(mutex)                                            \
 171     G_THREAD_ECF (mutex_lock,    (void)0, mutex, void)
 172 # define g_mutex_trylock(mutex)                                         \
 173     G_THREAD_ECF (mutex_trylock, TRUE,    mutex, gboolean)
 174 # define g_mutex_unlock(mutex)                                          \
 175     G_THREAD_ECF (mutex_unlock,  (void)0, mutex, void)
 176 # define g_cond_wait(cond, mutex)                                       \
 177     (g_thread_supported () ? ((void(*)(GCond*, GMutex*, gulong, gchar*))\
 178       g_thread_functions_for_glib_use.cond_wait)                        \
 179         (cond, mutex, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : (void) 0)
 180 # define g_cond_timed_wait(cond, mutex, abs_time)                       \
 181     (g_thread_supported () ?                                            \
 182       ((gboolean(*)(GCond*, GMutex*, GTimeVal*, gulong, gchar*))        \
 183         g_thread_functions_for_glib_use.cond_timed_wait)                \
 184           (cond, mutex, abs_time, G_MUTEX_DEBUG_MAGIC, G_STRLOC) : TRUE)
 185 #endif /* G_ERRORCHECK_MUTEXES */
 186
 187 #define g_thread_supported()    (g_threads_got_initialized)
 188 #define g_mutex_new()            G_THREAD_UF (mutex_new,      ())
 189 #define g_mutex_free(mutex)      G_THREAD_CF (mutex_free,     (void)0, (mutex))
 190 #define g_cond_new()             G_THREAD_UF (cond_new,       ())
 191 #define g_cond_signal(cond)      G_THREAD_CF (cond_signal,    (void)0, (cond))
 192 #define g_cond_broadcast(cond)   G_THREAD_CF (cond_broadcast, (void)0, (cond))
 193 #define g_cond_free(cond)        G_THREAD_CF (cond_free,      (void)0, (cond))
 194 #define g_private_new(destructor) G_THREAD_UF (private_new, (destructor))
 195 #define g_private_get(private_key) G_THREAD_CF (private_get, \
 196                                                 ((gpointer)private_key), \
 197                                                 (private_key))
 198 #define g_private_set(private_key, value) G_THREAD_CF (private_set, \
 199                                                        (void) (private_key = \
 200                                                         (GPrivate*) (value)), \
 201                                                        (private_key, value))
 202 #define g_thread_yield()              G_THREAD_CF (thread_yield, (void)0, ())
 203 #define g_thread_exit()               G_THREAD_CF (thread_exit, (void)0, ())
 204
 205 GThread* g_thread_create (GThreadFunc            thread_func,
 206                           gpointer               arg,
 207                           gulong                 stack_size,
 208                           gboolean               joinable,
 209                           gboolean               bound,
 210                           GThreadPriority        priority,
 211                           GError               **error);
 212 GThread* g_thread_self (void);
 213 void g_thread_join (GThread *thread);
 214 void g_thread_set_priority (GThread         *thread,
 215                             GThreadPriority  priority);
 216
 217 /* GStaticMutexes can be statically initialized with the value
 218  * G_STATIC_MUTEX_INIT, and then they can directly be used, that is
 219  * much easier, than having to explicitly allocate the mutex before
 220  * use
 221  */
 222 #define g_static_mutex_lock(mutex) \
 223     g_mutex_lock (g_static_mutex_get_mutex (mutex))
 224 #define g_static_mutex_trylock(mutex) \
 225     g_mutex_trylock (g_static_mutex_get_mutex (mutex))
 226 #define g_static_mutex_unlock(mutex) \
 227     g_mutex_unlock (g_static_mutex_get_mutex (mutex))
 228
 229 struct _GStaticPrivate
 230 {
 231   guint index;
 232 };
 233 #define G_STATIC_PRIVATE_INIT { 0 }
 234 gpointer g_static_private_get (GStaticPrivate   *private_key);
 235 void     g_static_private_set (GStaticPrivate   *private_key,
 236                                gpointer          data,
 237                                GDestroyNotify    notify);
 238 gpointer g_static_private_get_for_thread (GStaticPrivate *private_key,
 239                                           GThread        *thread);
 240 void g_static_private_set_for_thread (GStaticPrivate *private_key,
 241                                       GThread        *thread,
 242                                       gpointer        data,
 243                                       GDestroyNotify  notify);
 244
 245 typedef struct _GStaticRecMutex GStaticRecMutex;
 246 struct _GStaticRecMutex
 247 {
 248   GStaticMutex mutex;
 249   unsigned int depth;
 250   GSystemThread owner;
 251 };
 252
 253 #define G_STATIC_REC_MUTEX_INIT { G_STATIC_MUTEX_INIT }
 254 void     g_static_rec_mutex_lock        (GStaticRecMutex *mutex);
 255 gboolean g_static_rec_mutex_trylock     (GStaticRecMutex *mutex);
 256 void     g_static_rec_mutex_unlock      (GStaticRecMutex *mutex);
 257 void     g_static_rec_mutex_lock_full   (GStaticRecMutex *mutex,
 258                                          guint            depth);
 259 guint    g_static_rec_mutex_unlock_full (GStaticRecMutex *mutex);
 260
 261 typedef struct _GStaticRWLock GStaticRWLock;
 262 struct _GStaticRWLock
 263 {
 264   GStaticMutex mutex;
 265   GCond *read_cond;
 266   GCond *write_cond;
 267   guint read_counter;
 268   gboolean write;
 269   guint want_to_write;
 270 };
 271
 272 #define G_STATIC_RW_LOCK_INIT { G_STATIC_MUTEX_INIT, NULL, NULL, 0, FALSE, FALSE }
 273
 274 void      g_static_rw_lock_reader_lock    (GStaticRWLock* lock);
 275 gboolean  g_static_rw_lock_reader_trylock (GStaticRWLock* lock);
 276 void      g_static_rw_lock_reader_unlock  (GStaticRWLock* lock);
 277 void      g_static_rw_lock_writer_lock    (GStaticRWLock* lock);
 278 gboolean  g_static_rw_lock_writer_trylock (GStaticRWLock* lock);
 279 void      g_static_rw_lock_writer_unlock  (GStaticRWLock* lock);
 280 void      g_static_rw_lock_free (GStaticRWLock* lock);
 281
 282 /* these are some convenience macros that expand to nothing if GLib
 283  * was configured with --disable-threads. for using StaticMutexes,
 284  * you define them with G_LOCK_DEFINE_STATIC (name) or G_LOCK_DEFINE (name)
 285  * if you need to export the mutex. With G_LOCK_EXTERN (name) you can
 286  * declare such an globally defined lock. name is a unique identifier
 287  * for the protected varibale or code portion. locking, testing and
 288  * unlocking of such mutexes can be done with G_LOCK(), G_UNLOCK() and
 289  * G_TRYLOCK() respectively.
 290  */
 291 extern void glib_dummy_decl (void);
 292 #define G_LOCK_NAME(name)               g__ ## name ## _lock
 293 #ifdef  G_THREADS_ENABLED
 294 #  define G_LOCK_DEFINE_STATIC(name)    static G_LOCK_DEFINE (name)
 295 #  define G_LOCK_DEFINE(name)           \
 296     GStaticMutex G_LOCK_NAME (name) = G_STATIC_MUTEX_INIT
 297 #  define G_LOCK_EXTERN(name)           extern GStaticMutex G_LOCK_NAME (name)
 298
 299 #  ifdef G_DEBUG_LOCKS
 300 #    define G_LOCK(name)                G_STMT_START{             \
 301         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 302                "file %s: line %d (%s): locking: %s ",             \
 303                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 304                #name);                                            \
 305         g_static_mutex_lock (&G_LOCK_NAME (name));                \
 306      }G_STMT_END
 307 #    define G_UNLOCK(name)              G_STMT_START{             \
 308         g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                   \
 309                "file %s: line %d (%s): unlocking: %s ",           \
 310                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 311                #name);                                            \
 312        g_static_mutex_unlock (&G_LOCK_NAME (name));               \
 313      }G_STMT_END
 314 #    define G_TRYLOCK(name)                                       \
 315         (g_log (G_LOG_DOMAIN, G_LOG_LEVEL_DEBUG,                  \
 316                "file %s: line %d (%s): try locking: %s ",         \
 317                __FILE__,        __LINE__, G_GNUC_PRETTY_FUNCTION, \
 318                #name), g_static_mutex_trylock (&G_LOCK_NAME (name)))
 319 #  else  /* !G_DEBUG_LOCKS */
 320 #    define G_LOCK(name) g_static_mutex_lock       (&G_LOCK_NAME (name))
 321 #    define G_UNLOCK(name) g_static_mutex_unlock   (&G_LOCK_NAME (name))
 322 #    define G_TRYLOCK(name) g_static_mutex_trylock (&G_LOCK_NAME (name))
 323 #  endif /* !G_DEBUG_LOCKS */
 324 #else   /* !G_THREADS_ENABLED */
 325 #  define G_LOCK_DEFINE_STATIC(name)    extern void glib_dummy_decl (void)
 326 #  define G_LOCK_DEFINE(name)           extern void glib_dummy_decl (void)
 327 #  define G_LOCK_EXTERN(name)           extern void glib_dummy_decl (void)
 328 #  define G_LOCK(name)
 329 #  define G_UNLOCK(name)
 330 #  define G_TRYLOCK(name)               (TRUE)
 331 #endif  /* !G_THREADS_ENABLED */
 332
 333 G_END_DECLS
 334
 335 #endif /* __G_THREAD_H__ */
 336