williamr@2: /* -*- mode: C; c-file-style: "gnu" -*- */
williamr@2: /* dbus-threads.h  D-Bus threads handling
williamr@2:  *
williamr@2:  * Copyright (C) 2002  Red Hat Inc.
williamr@2:  * Portion Copyright © 2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.
williamr@2:  * Licensed under the Academic Free License version 2.1
williamr@2:  * 
williamr@2:  * This program is free software; you can redistribute it and/or modify
williamr@2:  * it under the terms of the GNU General Public License as published by
williamr@2:  * the Free Software Foundation; either version 2 of the License, or
williamr@2:  * (at your option) any later version.
williamr@2:  *
williamr@2:  * This program is distributed in the hope that it will be useful,
williamr@2:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
williamr@2:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
williamr@2:  * GNU General Public License for more details.
williamr@2:  * 
williamr@2:  * You should have received a copy of the GNU General Public License
williamr@2:  * along with this program; if not, write to the Free Software
williamr@2:  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
williamr@2:  *
williamr@2:  */
williamr@2: #if !defined (DBUS_INSIDE_DBUS_H) && !defined (DBUS_COMPILATION)
williamr@2: #error "Only <dbus/dbus.h> can be included directly, this file may disappear or change contents."
williamr@2: #endif
williamr@2: 
williamr@2: #ifndef DBUS_THREADS_H
williamr@2: #define DBUS_THREADS_H
williamr@2: 
williamr@2: #include <dbus/dbus-macros.h>
williamr@2: #include <dbus/dbus-types.h>
williamr@2: 
williamr@2: DBUS_BEGIN_DECLS
williamr@2: 
williamr@2: /**
williamr@2:  * @addtogroup DBusThreads
williamr@2:  * @{
williamr@2:  */
williamr@2: 
williamr@2: /** An opaque mutex type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */
williamr@2: typedef struct DBusMutex DBusMutex;
williamr@2: /** An opaque condition variable type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */
williamr@2: typedef struct DBusCondVar DBusCondVar;
williamr@2: 
williamr@2: /** Deprecated, provide DBusRecursiveMutexNewFunction instead. */
williamr@2: typedef DBusMutex*  (* DBusMutexNewFunction)    (void);
williamr@2: /** Deprecated, provide DBusRecursiveMutexFreeFunction instead. */
williamr@2: typedef void        (* DBusMutexFreeFunction)   (DBusMutex *mutex);
williamr@2: /** Deprecated, provide DBusRecursiveMutexLockFunction instead. Return value is lock success, but gets ignored in practice. */
williamr@2: typedef dbus_bool_t (* DBusMutexLockFunction)   (DBusMutex *mutex);
williamr@2: /** Deprecated, provide DBusRecursiveMutexUnlockFunction instead. Return value is unlock success, but gets ignored in practice. */
williamr@2: typedef dbus_bool_t (* DBusMutexUnlockFunction) (DBusMutex *mutex);
williamr@2: 
williamr@2: /** Creates a new recursively-lockable mutex, or returns #NULL if not
williamr@2:  * enough memory.  Can only fail due to lack of memory.  Found in
williamr@2:  * #DBusThreadFunctions. Do not just use PTHREAD_MUTEX_RECURSIVE for
williamr@2:  * this, because it does not save/restore the recursion count when
williamr@2:  * waiting on a condition. libdbus requires the Java-style behavior
williamr@2:  * where the mutex is fully unlocked to wait on a condition.
williamr@2:  */
williamr@2: typedef DBusMutex*  (* DBusRecursiveMutexNewFunction)    (void);
williamr@2: /** Frees a recursively-lockable mutex.  Found in #DBusThreadFunctions.
williamr@2:  */
williamr@2: typedef void        (* DBusRecursiveMutexFreeFunction)   (DBusMutex *mutex);
williamr@2: /** Locks a recursively-lockable mutex.  Found in #DBusThreadFunctions.
williamr@2:  * Can only fail due to lack of memory.
williamr@2:  */
williamr@2: typedef void        (* DBusRecursiveMutexLockFunction)   (DBusMutex *mutex);
williamr@2: /** Unlocks a recursively-lockable mutex.  Found in #DBusThreadFunctions.
williamr@2:  * Can only fail due to lack of memory.
williamr@2:  */
williamr@2: typedef void        (* DBusRecursiveMutexUnlockFunction) (DBusMutex *mutex);
williamr@2: 
williamr@2: /** Creates a new condition variable.  Found in #DBusThreadFunctions.
williamr@2:  * Can only fail (returning #NULL) due to lack of memory.
williamr@2:  */
williamr@2: typedef DBusCondVar*  (* DBusCondVarNewFunction)         (void);
williamr@2: /** Frees a condition variable.  Found in #DBusThreadFunctions.
williamr@2:  */
williamr@2: typedef void          (* DBusCondVarFreeFunction)        (DBusCondVar *cond);
williamr@2: 
williamr@2: /** Waits on a condition variable.  Found in
williamr@2:  * #DBusThreadFunctions. Must work with either a recursive or
williamr@2:  * nonrecursive mutex, whichever the thread implementation
williamr@2:  * provides. Note that PTHREAD_MUTEX_RECURSIVE does not work with
williamr@2:  * condition variables (does not save/restore the recursion count) so
williamr@2:  * don't try using simply pthread_cond_wait() and a
williamr@2:  * PTHREAD_MUTEX_RECURSIVE to implement this, it won't work right.
williamr@2:  *
williamr@2:  * Has no error conditions. Must succeed if it returns.
williamr@2:  */
williamr@2: typedef void          (* DBusCondVarWaitFunction)        (DBusCondVar *cond,
williamr@2: 							  DBusMutex   *mutex);
williamr@2: 
williamr@2: /** Waits on a condition variable with a timeout.  Found in
williamr@2:  *  #DBusThreadFunctions. Returns #TRUE if the wait did not
williamr@2:  *  time out, and #FALSE if it did.
williamr@2:  *
williamr@2:  * Has no error conditions. Must succeed if it returns. 
williamr@2:  */
williamr@2: typedef dbus_bool_t   (* DBusCondVarWaitTimeoutFunction) (DBusCondVar *cond,
williamr@2: 							  DBusMutex   *mutex,
williamr@2: 							  int          timeout_milliseconds);
williamr@2: /** Wakes one waiting thread on a condition variable.  Found in #DBusThreadFunctions.
williamr@2:  *
williamr@2:  * Has no error conditions. Must succeed if it returns.
williamr@2:  */
williamr@2: typedef void          (* DBusCondVarWakeOneFunction) (DBusCondVar *cond);
williamr@2: 
williamr@2: /** Wakes all waiting threads on a condition variable.  Found in #DBusThreadFunctions.
williamr@2:  *
williamr@2:  * Has no error conditions. Must succeed if it returns.
williamr@2:  */
williamr@2: typedef void          (* DBusCondVarWakeAllFunction) (DBusCondVar *cond);
williamr@2: 
williamr@2: /**
williamr@2:  * Flags indicating which functions are present in #DBusThreadFunctions. Used to allow
williamr@2:  * the library to detect older callers of dbus_threads_init() if new possible functions
williamr@2:  * are added to #DBusThreadFunctions.
williamr@2:  */
williamr@2: typedef enum 
williamr@2: {
williamr@2:   DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK      = 1 << 0,
williamr@2:   DBUS_THREAD_FUNCTIONS_MUTEX_FREE_MASK     = 1 << 1,
williamr@2:   DBUS_THREAD_FUNCTIONS_MUTEX_LOCK_MASK     = 1 << 2,
williamr@2:   DBUS_THREAD_FUNCTIONS_MUTEX_UNLOCK_MASK   = 1 << 3,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK    = 1 << 4,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK   = 1 << 5,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK   = 1 << 6,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK   = 1 << 7,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK = 1 << 8,
williamr@2:   DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK = 1 << 9,
williamr@2:   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_NEW_MASK    = 1 << 10,
williamr@2:   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_FREE_MASK   = 1 << 11,
williamr@2:   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_LOCK_MASK   = 1 << 12,
williamr@2:   DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_UNLOCK_MASK = 1 << 13,
williamr@2:   DBUS_THREAD_FUNCTIONS_ALL_MASK     = (1 << 14) - 1
williamr@2: } DBusThreadFunctionsMask;
williamr@2: 
williamr@2: /**
williamr@2:  * Functions that must be implemented to make the D-Bus library
williamr@2:  * thread-aware. The recursive mutex functions should be specified
williamr@2:  * rather than the old, deprecated nonrecursive ones.
williamr@2:  *
williamr@2:  * The condition variable functions have to work with recursive
williamr@2:  * mutexes if you provide those, or with nonrecursive mutexes if you
williamr@2:  * provide those.
williamr@2:  *
williamr@2:  * If implementing threads using pthreads, be aware that
williamr@2:  * PTHREAD_MUTEX_RECURSIVE is broken in combination with condition
williamr@2:  * variables. libdbus relies on the Java-style behavior that when
williamr@2:  * waiting on a condition, the recursion count is saved and restored,
williamr@2:  * and the mutex is completely unlocked, not just decremented one
williamr@2:  * level of recursion.
williamr@2:  *
williamr@2:  * Thus with pthreads you probably have to roll your own emulated
williamr@2:  * recursive mutexes, you can't use PTHREAD_MUTEX_RECURSIVE. This is
williamr@2:  * what dbus_threads_init_default() does on platforms that use
williamr@2:  * pthreads.
williamr@2:  */
williamr@2: typedef struct
williamr@2: {
williamr@2:   unsigned int mask; /**< Mask indicating which functions are present. */
williamr@2: 
williamr@2:   DBusMutexNewFunction mutex_new; /**< Function to create a mutex; optional and deprecated. */
williamr@2:   DBusMutexFreeFunction mutex_free; /**< Function to free a mutex; optional and deprecated. */
williamr@2:   DBusMutexLockFunction mutex_lock; /**< Function to lock a mutex; optional and deprecated. */
williamr@2:   DBusMutexUnlockFunction mutex_unlock; /**< Function to unlock a mutex; optional and deprecated. */
williamr@2: 
williamr@2:   DBusCondVarNewFunction condvar_new; /**< Function to create a condition variable */
williamr@2:   DBusCondVarFreeFunction condvar_free; /**< Function to free a condition variable */
williamr@2:   DBusCondVarWaitFunction condvar_wait; /**< Function to wait on a condition */
williamr@2:   DBusCondVarWaitTimeoutFunction condvar_wait_timeout; /**< Function to wait on a condition with a timeout */
williamr@2:   DBusCondVarWakeOneFunction condvar_wake_one; /**< Function to wake one thread waiting on the condition */
williamr@2:   DBusCondVarWakeAllFunction condvar_wake_all; /**< Function to wake all threads waiting on the condition */
williamr@2:  
williamr@2:   DBusRecursiveMutexNewFunction recursive_mutex_new; /**< Function to create a recursive mutex */
williamr@2:   DBusRecursiveMutexFreeFunction recursive_mutex_free; /**< Function to free a recursive mutex */
williamr@2:   DBusRecursiveMutexLockFunction recursive_mutex_lock; /**< Function to lock a recursive mutex */
williamr@2:   DBusRecursiveMutexUnlockFunction recursive_mutex_unlock; /**< Function to unlock a recursive mutex */
williamr@2: 
williamr@2:   void (* padding1) (void); /**< Reserved for future expansion */
williamr@2:   void (* padding2) (void); /**< Reserved for future expansion */
williamr@2:   void (* padding3) (void); /**< Reserved for future expansion */
williamr@2:   void (* padding4) (void); /**< Reserved for future expansion */
williamr@2:   
williamr@2: } DBusThreadFunctions;
williamr@2: 
williamr@2: #ifdef __SYMBIAN32__
williamr@2: IMPORT_C
williamr@2: #endif
williamr@2: dbus_bool_t  dbus_threads_init         (const DBusThreadFunctions *functions);
williamr@2: #ifdef __SYMBIAN32__
williamr@2: IMPORT_C
williamr@2: #endif
williamr@2: dbus_bool_t  dbus_threads_init_default (void);
williamr@2: 
williamr@2: /** @} */
williamr@2: 
williamr@2: DBUS_END_DECLS
williamr@2: 
williamr@2: #endif /* DBUS_THREADS_H */