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/*
This file is part of GNUnet.
(C) 2012 Christian Grothoff (and other contributing authors)
GNUnet 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, or (at your
option) any later version.
GNUnet 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 GNUnet; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
/**
* @file include/gnunet_lockmanager_service.h
* @brief API for the lockmanger service
* @author Sree Harsha Totakura
*/
#ifndef GNUNET_LOCKMANAGER_SERVICE_H
#define GNUNET_LOCKMANAGER_SERVICE_H
#ifdef __cplusplus
extern "C"
{
#if 0 /* keep Emacsens' auto-indent happy */
}
#endif
#endif
#include "gnunet_configuration_lib.h"
/**
* Opaque handle for the lockmanager service
*/
struct GNUNET_LOCKMANAGER_Handle;
/**
* Connect to the lockmanager service
*
* @param cfg the configuration to use
*
* @return upon success the handle to the service; NULL upon error
*/
struct GNUNET_LOCKMANAGER_Handle *
GNUNET_LOCKMANAGER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg);
/**
* Disconnect from the lockmanager service
*
* @param handle the handle to the lockmanager service
*/
void
GNUNET_LOCKMANAGER_disconnect (struct GNUNET_LOCKMANAGER_Handle *handle);
/**
* Enumeration for status
*/
enum GNUNET_LOCKMANAGER_Status
{
/**
* Signifies a successful operation
*/
GNUNET_LOCKMANAGER_SUCCESS = 1,
/**
* Used to signal that a lock is no longer valid. It must then be released
*/
GNUNET_LOCKMANAGER_RELEASE
};
/**
* This callback will be called when a lock has been successfully acquired or
* when an acquired lock has been lost (happens when the lockmanager service
* crashes/restarts).
*
* @param cls the closure from GNUNET_LOCKMANAGER_lock call
*
* @param domain_name the locking domain of the lock
*
* @param lock the lock for which this status is relevant
*
* @param status GNUNET_LOCKMANAGER_SUCCESS if the lock has been successfully
* acquired; GNUNET_LOCKMANAGER_RELEASE when the acquired lock is lost
*/
typedef void
(*GNUNET_LOCKMANAGER_StatusCallback) (void *cls,
const char *domain_name,
uint32_t lock,
enum GNUNET_LOCKMANAGER_Status
status);
/**
* Opaque handle to locking request
*/
struct GNUNET_LOCKMANAGER_LockingRequest;
/**
* Tries to acquire the given lock(even if the lock has been lost) until the
* request is called. If the lock is available the status_cb will be
* called. If the lock is busy then the request is queued and status_cb
* will be called when the lock has been made available and acquired by us.
*
* @param handle the handle to the lockmanager service
*
* @param domain_name name of the locking domain. Clients who want to share
* locks must use the same name for the locking domain. Also the
* domain_name should be selected with the prefix
* "GNUNET_<PROGRAM_NAME>_" to avoid domain name collisions.
*
*
* @param lock which lock to lock
*
* @param status_cb the callback for signalling when the lock is acquired and
* when it is lost
*
* @param status_cb_cls the closure to the above callback
*
* @return the locking request handle for this request
*/
struct GNUNET_LOCKMANAGER_LockingRequest *
GNUNET_LOCKMANAGER_acquire_lock (struct GNUNET_LOCKMANAGER_Handle *handle,
const char *domain_name,
uint32_t lock,
GNUNET_LOCKMANAGER_StatusCallback
status_cb,
void *status_cb_cls);
/**
* Function to cancel the locking request generated by
* GNUNET_LOCKMANAGER_acquire_lock. If the lock is acquired us then the lock is
* released. GNUNET_LOCKMANAGER_StatusCallback will not be called upon any
* status changes resulting due to this call.
*
* @param request the LockingRequest to cancel
*/
void
GNUNET_LOCKMANAGER_cancel_request (struct GNUNET_LOCKMANAGER_LockingRequest
*request);
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif
/* ifndef GNUNET_LOCKMANAGER_SERVICE_H */
#endif
/* end of gnunet_lockmanager_service.h */
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