tor-android/external/badvpn_dns/ncd/extra/BEventLock.h

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2015-01-25 11:08:34 +00:00
/**
* @file BEventLock.h
* @author Ambroz Bizjak <ambrop7@gmail.com>
*
* @section LICENSE
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the author nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @section DESCRIPTION
*
* A FIFO lock for events using the job queue ({@link BPending}).
*/
#ifndef BADVPN_BEVENTLOCK_H
#define BADVPN_BEVENTLOCK_H
#include <misc/debugcounter.h>
#include <structure/LinkedList1.h>
#include <base/DebugObject.h>
#include <base/BPending.h>
/**
* Event context handler called when the lock job has acquired the lock
* after requesting the lock with {@link BEventLockJob_Wait}.
* The object was in waiting state.
* The object enters locked state before the handler is called.
*
* @param user as in {@link BEventLockJob_Init}
*/
typedef void (*BEventLock_handler) (void *user);
/**
* A FIFO lock for events using the job queue ({@link BPending}).
*/
typedef struct {
LinkedList1 jobs;
BPending exec_job;
DebugObject d_obj;
DebugCounter pending_ctr;
} BEventLock;
/**
* An object that can request a {@link BEventLock} lock.
*/
typedef struct {
BEventLock *l;
BEventLock_handler handler;
void *user;
int pending;
LinkedList1Node pending_node;
DebugObject d_obj;
} BEventLockJob;
/**
* Initializes the object.
*
* @param o the object
* @param pg pending group
*/
void BEventLock_Init (BEventLock *o, BPendingGroup *pg);
/**
* Frees the object.
* There must be no {@link BEventLockJob} objects using this lock
* (regardless of their state).
*
* @param o the object
*/
void BEventLock_Free (BEventLock *o);
/**
* Initializes the object.
* The object is initialized in idle state.
*
* @param o the object
* @param l the lock
* @param handler handler to call when the lock is aquired
* @param user value to pass to handler
*/
void BEventLockJob_Init (BEventLockJob *o, BEventLock *l, BEventLock_handler handler, void *user);
/**
* Frees the object.
*
* @param o the object
*/
void BEventLockJob_Free (BEventLockJob *o);
/**
* Requests the lock.
* The object must be in idle state.
* The object enters waiting state.
*
* @param o the object
*/
void BEventLockJob_Wait (BEventLockJob *o);
/**
* Aborts the lock request or releases the lock.
* The object must be in waiting or locked state.
* The object enters idle state.
*
* @param o the object
*/
void BEventLockJob_Release (BEventLockJob *o);
#endif