/* -*- mode: C; c-file-style: "gnu" -*- */

/* dbus-threads.h  D-Bus threads handling

 *

 * Copyright (C) 2002  Red Hat Inc.

 * Portion Copyright © 2008 Nokia Corporation and/or its subsidiary(-ies). All rights reserved.

 * Licensed under the Academic Free License version 2.1

 * 

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 * 

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 *

 */

#if !defined (DBUS_INSIDE_DBUS_H) && !defined (DBUS_COMPILATION)

#error "Only <dbus/dbus.h> can be included directly, this file may disappear or change contents."

#endif

#ifndef DBUS_THREADS_H

#define DBUS_THREADS_H

#include <dbus/dbus-macros.h>

#include <dbus/dbus-types.h>

DBUS_BEGIN_DECLS

/**

 * @addtogroup DBusThreads

 * @{

 */

/** An opaque mutex type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */

typedef struct DBusMutex DBusMutex;

/** An opaque condition variable type provided by the #DBusThreadFunctions implementation installed by dbus_threads_init(). */

typedef struct DBusCondVar DBusCondVar;

/** Deprecated, provide DBusRecursiveMutexNewFunction instead. */

typedef DBusMutex*  (* DBusMutexNewFunction)    (void);

/** Deprecated, provide DBusRecursiveMutexFreeFunction instead. */

typedef void        (* DBusMutexFreeFunction)   (DBusMutex *mutex);

/** Deprecated, provide DBusRecursiveMutexLockFunction instead. Return value is lock success, but gets ignored in practice. */

typedef dbus_bool_t (* DBusMutexLockFunction)   (DBusMutex *mutex);

/** Deprecated, provide DBusRecursiveMutexUnlockFunction instead. Return value is unlock success, but gets ignored in practice. */

typedef dbus_bool_t (* DBusMutexUnlockFunction) (DBusMutex *mutex);

/** Creates a new recursively-lockable mutex, or returns #NULL if not

 * enough memory.  Can only fail due to lack of memory.  Found in

 * #DBusThreadFunctions. Do not just use PTHREAD_MUTEX_RECURSIVE for

 * this, because it does not save/restore the recursion count when

 * waiting on a condition. libdbus requires the Java-style behavior

 * where the mutex is fully unlocked to wait on a condition.

 */

typedef DBusMutex*  (* DBusRecursiveMutexNewFunction)    (void);

/** Frees a recursively-lockable mutex.  Found in #DBusThreadFunctions.

 */

typedef void        (* DBusRecursiveMutexFreeFunction)   (DBusMutex *mutex);

/** Locks a recursively-lockable mutex.  Found in #DBusThreadFunctions.

 * Can only fail due to lack of memory.

 */

typedef void        (* DBusRecursiveMutexLockFunction)   (DBusMutex *mutex);

/** Unlocks a recursively-lockable mutex.  Found in #DBusThreadFunctions.

 * Can only fail due to lack of memory.

 */

typedef void        (* DBusRecursiveMutexUnlockFunction) (DBusMutex *mutex);

/** Creates a new condition variable.  Found in #DBusThreadFunctions.

 * Can only fail (returning #NULL) due to lack of memory.

 */

typedef DBusCondVar*  (* DBusCondVarNewFunction)         (void);

/** Frees a condition variable.  Found in #DBusThreadFunctions.

 */

typedef void          (* DBusCondVarFreeFunction)        (DBusCondVar *cond);

/** Waits on a condition variable.  Found in

 * #DBusThreadFunctions. Must work with either a recursive or

 * nonrecursive mutex, whichever the thread implementation

 * provides. Note that PTHREAD_MUTEX_RECURSIVE does not work with

 * condition variables (does not save/restore the recursion count) so

 * don't try using simply pthread_cond_wait() and a

 * PTHREAD_MUTEX_RECURSIVE to implement this, it won't work right.

 *

 * Has no error conditions. Must succeed if it returns.

 */

typedef void          (* DBusCondVarWaitFunction)        (DBusCondVar *cond,

							  DBusMutex   *mutex);

/** Waits on a condition variable with a timeout.  Found in

 *  #DBusThreadFunctions. Returns #TRUE if the wait did not

 *  time out, and #FALSE if it did.

 *

 * Has no error conditions. Must succeed if it returns. 

 */

typedef dbus_bool_t   (* DBusCondVarWaitTimeoutFunction) (DBusCondVar *cond,

							  DBusMutex   *mutex,

							  int          timeout_milliseconds);

/** Wakes one waiting thread on a condition variable.  Found in #DBusThreadFunctions.

 *

 * Has no error conditions. Must succeed if it returns.

 */

typedef void          (* DBusCondVarWakeOneFunction) (DBusCondVar *cond);

/** Wakes all waiting threads on a condition variable.  Found in #DBusThreadFunctions.

 *

 * Has no error conditions. Must succeed if it returns.

 */

typedef void          (* DBusCondVarWakeAllFunction) (DBusCondVar *cond);

/**

 * Flags indicating which functions are present in #DBusThreadFunctions. Used to allow

 * the library to detect older callers of dbus_threads_init() if new possible functions

 * are added to #DBusThreadFunctions.

 */

typedef enum 

{

  DBUS_THREAD_FUNCTIONS_MUTEX_NEW_MASK      = 1 << 0,

  DBUS_THREAD_FUNCTIONS_MUTEX_FREE_MASK     = 1 << 1,

  DBUS_THREAD_FUNCTIONS_MUTEX_LOCK_MASK     = 1 << 2,

  DBUS_THREAD_FUNCTIONS_MUTEX_UNLOCK_MASK   = 1 << 3,

  DBUS_THREAD_FUNCTIONS_CONDVAR_NEW_MASK    = 1 << 4,

  DBUS_THREAD_FUNCTIONS_CONDVAR_FREE_MASK   = 1 << 5,

  DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_MASK   = 1 << 6,

  DBUS_THREAD_FUNCTIONS_CONDVAR_WAIT_TIMEOUT_MASK   = 1 << 7,

  DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ONE_MASK = 1 << 8,

  DBUS_THREAD_FUNCTIONS_CONDVAR_WAKE_ALL_MASK = 1 << 9,

  DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_NEW_MASK    = 1 << 10,

  DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_FREE_MASK   = 1 << 11,

  DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_LOCK_MASK   = 1 << 12,

  DBUS_THREAD_FUNCTIONS_RECURSIVE_MUTEX_UNLOCK_MASK = 1 << 13,

  DBUS_THREAD_FUNCTIONS_ALL_MASK     = (1 << 14) - 1

} DBusThreadFunctionsMask;

/**

 * Functions that must be implemented to make the D-Bus library

 * thread-aware. The recursive mutex functions should be specified

 * rather than the old, deprecated nonrecursive ones.

 *

 * The condition variable functions have to work with recursive

 * mutexes if you provide those, or with nonrecursive mutexes if you

 * provide those.

 *

 * If implementing threads using pthreads, be aware that

 * PTHREAD_MUTEX_RECURSIVE is broken in combination with condition

 * variables. libdbus relies on the Java-style behavior that when

 * waiting on a condition, the recursion count is saved and restored,

 * and the mutex is completely unlocked, not just decremented one

 * level of recursion.

 *

 * Thus with pthreads you probably have to roll your own emulated

 * recursive mutexes, you can't use PTHREAD_MUTEX_RECURSIVE. This is

 * what dbus_threads_init_default() does on platforms that use

 * pthreads.

 */

typedef struct

{

  unsigned int mask; /**< Mask indicating which functions are present. */

  DBusMutexNewFunction mutex_new; /**< Function to create a mutex; optional and deprecated. */

  DBusMutexFreeFunction mutex_free; /**< Function to free a mutex; optional and deprecated. */

  DBusMutexLockFunction mutex_lock; /**< Function to lock a mutex; optional and deprecated. */

  DBusMutexUnlockFunction mutex_unlock; /**< Function to unlock a mutex; optional and deprecated. */

  DBusCondVarNewFunction condvar_new; /**< Function to create a condition variable */

  DBusCondVarFreeFunction condvar_free; /**< Function to free a condition variable */

  DBusCondVarWaitFunction condvar_wait; /**< Function to wait on a condition */

  DBusCondVarWaitTimeoutFunction condvar_wait_timeout; /**< Function to wait on a condition with a timeout */

  DBusCondVarWakeOneFunction condvar_wake_one; /**< Function to wake one thread waiting on the condition */

  DBusCondVarWakeAllFunction condvar_wake_all; /**< Function to wake all threads waiting on the condition */

  DBusRecursiveMutexNewFunction recursive_mutex_new; /**< Function to create a recursive mutex */

  DBusRecursiveMutexFreeFunction recursive_mutex_free; /**< Function to free a recursive mutex */

  DBusRecursiveMutexLockFunction recursive_mutex_lock; /**< Function to lock a recursive mutex */

  DBusRecursiveMutexUnlockFunction recursive_mutex_unlock; /**< Function to unlock a recursive mutex */

  void (* padding1) (void); /**< Reserved for future expansion */

  void (* padding2) (void); /**< Reserved for future expansion */

  void (* padding3) (void); /**< Reserved for future expansion */

  void (* padding4) (void); /**< Reserved for future expansion */

} DBusThreadFunctions;

#ifdef __SYMBIAN32__

IMPORT_C

#endif

dbus_bool_t  dbus_threads_init         (const DBusThreadFunctions *functions);

#ifdef __SYMBIAN32__

IMPORT_C

#endif

dbus_bool_t  dbus_threads_init_default (void);

/** @} */

DBUS_END_DECLS

#endif /* DBUS_THREADS_H */