/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */ /* dbus-threads.h D-Bus threads handling * * Copyright (C) 2002 Red Hat Inc. * * 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA * */ #if !defined (DBUS_INSIDE_DBUS_H) && !defined (DBUS_COMPILATION) #error "Only can be included directly, this file may disappear or change contents." #endif #ifndef DBUS_THREADS_H #define DBUS_THREADS_H #include #include 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; dbus_bool_t dbus_threads_init (const DBusThreadFunctions *functions); dbus_bool_t dbus_threads_init_default (void); /** @} */ DBUS_END_DECLS #endif /* DBUS_THREADS_H */