epoc32/include/stdapis/dbus-1.0/dbus/dbus-threads.h
author William Roberts <williamr@symbian.org>
Wed, 31 Mar 2010 12:27:01 +0100
branchSymbian2
changeset 3 e1b950c65cb4
permissions -rw-r--r--
Attempt to represent the S^2->S^3 header reorganisation as a series of "hg rename" operations
     1 /* -*- mode: C; c-file-style: "gnu" -*- */
     2 /* dbus-threads.h  D-Bus threads handling
     3  *
     4  * Copyright (C) 2002  Red Hat Inc.
     5  * Portion Copyright © 2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.
     6  * Licensed under the Academic Free License version 2.1
     7  * 
     8  * This program is free software; you can redistribute it and/or modify
     9  * it under the terms of the GNU General Public License as published by
    10  * the Free Software Foundation; either version 2 of the License, or
    11  * (at your option) any later version.
    12  *
    13  * This program is distributed in the hope that it will be useful,
    14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16  * GNU General Public License for more details.
    17  * 
    18  * You should have received a copy of the GNU General Public License
    19  * along with this program; if not, write to the Free Software
    20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    21  *
    22  */
    23 #if !defined (DBUS_INSIDE_DBUS_H) && !defined (DBUS_COMPILATION)
    24 #error "Only <dbus/dbus.h> can be included directly, this file may disappear or change contents."
    25 #endif
    26 
    27 #ifndef DBUS_THREADS_H
    28 #define DBUS_THREADS_H
    29 
    30 #include <dbus/dbus-macros.h>
    31 #include <dbus/dbus-types.h>
    32 
    33 DBUS_BEGIN_DECLS
    34 
    35 /**
    36  * @addtogroup DBusThreads
    37  * @{
    38  */
    39 
    40 /** An opaque mutex type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */
    41 typedef struct DBusMutex DBusMutex;
    42 /** An opaque condition variable type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */
    43 typedef struct DBusCondVar DBusCondVar;
    44 
    45 /** Deprecated, provide DBusRecursiveMutexNewFunction instead. */
    46 typedef DBusMutex*  (* DBusMutexNewFunction)    (void);
    47 /** Deprecated, provide DBusRecursiveMutexFreeFunction instead. */
    48 typedef void        (* DBusMutexFreeFunction)   (DBusMutex *mutex);
    49 /** Deprecated, provide DBusRecursiveMutexLockFunction instead. Return value is lock success, but gets ignored in practice. */
    50 typedef dbus_bool_t (* DBusMutexLockFunction)   (DBusMutex *mutex);
    51 /** Deprecated, provide DBusRecursiveMutexUnlockFunction instead. Return value is unlock success, but gets ignored in practice. */
    52 typedef dbus_bool_t (* DBusMutexUnlockFunction) (DBusMutex *mutex);
    53 
    54 /** Creates a new recursively-lockable mutex, or returns #NULL if not
    55  * enough memory.  Can only fail due to lack of memory.  Found in
    56  * #DBusThreadFunctions. Do not just use PTHREAD_MUTEX_RECURSIVE for
    57  * this, because it does not save/restore the recursion count when
    58  * waiting on a condition. libdbus requires the Java-style behavior
    59  * where the mutex is fully unlocked to wait on a condition.
    60  */
    61 typedef DBusMutex*  (* DBusRecursiveMutexNewFunction)    (void);
    62 /** Frees a recursively-lockable mutex.  Found in #DBusThreadFunctions.
    63  */
    64 typedef void        (* DBusRecursiveMutexFreeFunction)   (DBusMutex *mutex);
    65 /** Locks a recursively-lockable mutex.  Found in #DBusThreadFunctions.
    66  * Can only fail due to lack of memory.
    67  */
    68 typedef void        (* DBusRecursiveMutexLockFunction)   (DBusMutex *mutex);
    69 /** Unlocks a recursively-lockable mutex.  Found in #DBusThreadFunctions.
    70  * Can only fail due to lack of memory.
    71  */
    72 typedef void        (* DBusRecursiveMutexUnlockFunction) (DBusMutex *mutex);
    73 
    74 /** Creates a new condition variable.  Found in #DBusThreadFunctions.
    75  * Can only fail (returning #NULL) due to lack of memory.
    76  */
    77 typedef DBusCondVar*  (* DBusCondVarNewFunction)         (void);
    78 /** Frees a condition variable.  Found in #DBusThreadFunctions.
    79  */
    80 typedef void          (* DBusCondVarFreeFunction)        (DBusCondVar *cond);
    81 
    82 /** Waits on a condition variable.  Found in
    83  * #DBusThreadFunctions. Must work with either a recursive or
    84  * nonrecursive mutex, whichever the thread implementation
    85  * provides. Note that PTHREAD_MUTEX_RECURSIVE does not work with
    86  * condition variables (does not save/restore the recursion count) so
    87  * don't try using simply pthread_cond_wait() and a
    88  * PTHREAD_MUTEX_RECURSIVE to implement this, it won't work right.
    89  *
    90  * Has no error conditions. Must succeed if it returns.
    91  */
    92 typedef void          (* DBusCondVarWaitFunction)        (DBusCondVar *cond,
    93 							  DBusMutex   *mutex);
    94 
    95 /** Waits on a condition variable with a timeout.  Found in
    96  *  #DBusThreadFunctions. Returns #TRUE if the wait did not
    97  *  time out, and #FALSE if it did.
    98  *
    99  * Has no error conditions. Must succeed if it returns. 
   100  */
   101 typedef dbus_bool_t   (* DBusCondVarWaitTimeoutFunction) (DBusCondVar *cond,
   102 							  DBusMutex   *mutex,
   103 							  int          timeout_milliseconds);
   104 /** Wakes one waiting thread on a condition variable.  Found in #DBusThreadFunctions.
   105  *
   106  * Has no error conditions. Must succeed if it returns.
   107  */
   108 typedef void          (* DBusCondVarWakeOneFunction) (DBusCondVar *cond);
   109 
   110 /** Wakes all waiting threads on a condition variable.  Found in #DBusThreadFunctions.
   111  *
   112  * Has no error conditions. Must succeed if it returns.
   113  */
   114 typedef void          (* DBusCondVarWakeAllFunction) (DBusCondVar *cond);
   115 
   116 /**
   117  * Flags indicating which functions are present in #DBusThreadFunctions. Used to allow
   118  * the library to detect older callers of dbus_threads_init() if new possible functions
   119  * are added to #DBusThreadFunctions.
   120  */
   121 typedef enum 
   122 {
   123   DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK      = 1 << 0,
   124   DBUS_THREAD_FUNCTIONS_MUTEX_FREE_MASK     = 1 << 1,
   125   DBUS_THREAD_FUNCTIONS_MUTEX_LOCK_MASK     = 1 << 2,
   126   DBUS_THREAD_FUNCTIONS_MUTEX_UNLOCK_MASK   = 1 << 3,
   127   DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK    = 1 << 4,
   128   DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK   = 1 << 5,
   129   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK   = 1 << 6,
   130   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK   = 1 << 7,
   131   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK = 1 << 8,
   132   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK = 1 << 9,
   133   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_NEW_MASK    = 1 << 10,
   134   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_FREE_MASK   = 1 << 11,
   135   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_LOCK_MASK   = 1 << 12,
   136   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_UNLOCK_MASK = 1 << 13,
   137   DBUS_THREAD_FUNCTIONS_ALL_MASK     = (1 << 14) - 1
   138 } DBusThreadFunctionsMask;
   139 
   140 /**
   141  * Functions that must be implemented to make the D-Bus library
   142  * thread-aware. The recursive mutex functions should be specified
   143  * rather than the old, deprecated nonrecursive ones.
   144  *
   145  * The condition variable functions have to work with recursive
   146  * mutexes if you provide those, or with nonrecursive mutexes if you
   147  * provide those.
   148  *
   149  * If implementing threads using pthreads, be aware that
   150  * PTHREAD_MUTEX_RECURSIVE is broken in combination with condition
   151  * variables. libdbus relies on the Java-style behavior that when
   152  * waiting on a condition, the recursion count is saved and restored,
   153  * and the mutex is completely unlocked, not just decremented one
   154  * level of recursion.
   155  *
   156  * Thus with pthreads you probably have to roll your own emulated
   157  * recursive mutexes, you can't use PTHREAD_MUTEX_RECURSIVE. This is
   158  * what dbus_threads_init_default() does on platforms that use
   159  * pthreads.
   160  */
   161 typedef struct
   162 {
   163   unsigned int mask; /**< Mask indicating which functions are present. */
   164 
   165   DBusMutexNewFunction mutex_new; /**< Function to create a mutex; optional and deprecated. */
   166   DBusMutexFreeFunction mutex_free; /**< Function to free a mutex; optional and deprecated. */
   167   DBusMutexLockFunction mutex_lock; /**< Function to lock a mutex; optional and deprecated. */
   168   DBusMutexUnlockFunction mutex_unlock; /**< Function to unlock a mutex; optional and deprecated. */
   169 
   170   DBusCondVarNewFunction condvar_new; /**< Function to create a condition variable */
   171   DBusCondVarFreeFunction condvar_free; /**< Function to free a condition variable */
   172   DBusCondVarWaitFunction condvar_wait; /**< Function to wait on a condition */
   173   DBusCondVarWaitTimeoutFunction condvar_wait_timeout; /**< Function to wait on a condition with a timeout */
   174   DBusCondVarWakeOneFunction condvar_wake_one; /**< Function to wake one thread waiting on the condition */
   175   DBusCondVarWakeAllFunction condvar_wake_all; /**< Function to wake all threads waiting on the condition */
   176  
   177   DBusRecursiveMutexNewFunction recursive_mutex_new; /**< Function to create a recursive mutex */
   178   DBusRecursiveMutexFreeFunction recursive_mutex_free; /**< Function to free a recursive mutex */
   179   DBusRecursiveMutexLockFunction recursive_mutex_lock; /**< Function to lock a recursive mutex */
   180   DBusRecursiveMutexUnlockFunction recursive_mutex_unlock; /**< Function to unlock a recursive mutex */
   181 
   182   void (* padding1) (void); /**< Reserved for future expansion */
   183   void (* padding2) (void); /**< Reserved for future expansion */
   184   void (* padding3) (void); /**< Reserved for future expansion */
   185   void (* padding4) (void); /**< Reserved for future expansion */
   186   
   187 } DBusThreadFunctions;
   188 
   189 #ifdef __SYMBIAN32__
   190 IMPORT_C
   191 #endif
   192 dbus_bool_t  dbus_threads_init         (const DBusThreadFunctions *functions);
   193 #ifdef __SYMBIAN32__
   194 IMPORT_C
   195 #endif
   196 dbus_bool_t  dbus_threads_init_default (void);
   197 
   198 /** @} */
   199 
   200 DBUS_END_DECLS
   201 
   202 #endif /* DBUS_THREADS_H */