michael@0: /*
michael@0:  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
michael@0:  *
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 1. Redistributions of source code must retain the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer.
michael@0:  * 2. Redistributions in binary form must reproduce the above copyright
michael@0:  *    notice, this list of conditions and the following disclaimer in the
michael@0:  *    documentation and/or other materials provided with the distribution.
michael@0:  * 3. The name of the author may not be used to endorse or promote products
michael@0:  *    derived from this software without specific prior written permission.
michael@0:  *
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
michael@0:  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
michael@0:  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
michael@0:  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
michael@0:  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
michael@0:  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
michael@0:  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
michael@0:  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
michael@0:  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
michael@0:  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  */
michael@0: #ifndef _DEFER_INTERNAL_H_
michael@0: #define _DEFER_INTERNAL_H_
michael@0: 
michael@0: #ifdef __cplusplus
michael@0: extern "C" {
michael@0: #endif
michael@0: 
michael@0: #include "event2/event-config.h"
michael@0: #include <sys/queue.h>
michael@0: 
michael@0: struct deferred_cb;
michael@0: 
michael@0: typedef void (*deferred_cb_fn)(struct deferred_cb *, void *);
michael@0: 
michael@0: /** A deferred_cb is a callback that can be scheduled to run as part of
michael@0:  * an event_base's event_loop, rather than running immediately. */
michael@0: struct deferred_cb {
michael@0: 	/** Links to the adjacent active (pending) deferred_cb objects. */
michael@0: 	TAILQ_ENTRY (deferred_cb) cb_next;
michael@0: 	/** True iff this deferred_cb is pending in an event_base. */
michael@0: 	unsigned queued : 1;
michael@0: 	/** The function to execute when the callback runs. */
michael@0: 	deferred_cb_fn cb;
michael@0: 	/** The function's second argument. */
michael@0: 	void *arg;
michael@0: };
michael@0: 
michael@0: /** A deferred_cb_queue is a list of deferred_cb that we can add to and run. */
michael@0: struct deferred_cb_queue {
michael@0: 	/** Lock used to protect the queue. */
michael@0: 	void *lock;
michael@0: 
michael@0: 	/** How many entries are in the queue? */
michael@0: 	int active_count;
michael@0: 
michael@0: 	/** Function called when adding to the queue from another thread. */
michael@0: 	void (*notify_fn)(struct deferred_cb_queue *, void *);
michael@0: 	void *notify_arg;
michael@0: 
michael@0: 	/** Deferred callback management: a list of deferred callbacks to
michael@0: 	 * run active the active events. */
michael@0: 	TAILQ_HEAD (deferred_cb_list, deferred_cb) deferred_cb_list;
michael@0: };
michael@0: 
michael@0: /**
michael@0:    Initialize an empty, non-pending deferred_cb.
michael@0: 
michael@0:    @param deferred The deferred_cb structure to initialize.
michael@0:    @param cb The function to run when the deferred_cb executes.
michael@0:    @param arg The function's second argument.
michael@0:  */
michael@0: void event_deferred_cb_init(struct deferred_cb *, deferred_cb_fn, void *);
michael@0: /**
michael@0:    Cancel a deferred_cb if it is currently scheduled in an event_base.
michael@0:  */
michael@0: void event_deferred_cb_cancel(struct deferred_cb_queue *, struct deferred_cb *);
michael@0: /**
michael@0:    Activate a deferred_cb if it is not currently scheduled in an event_base.
michael@0:  */
michael@0: void event_deferred_cb_schedule(struct deferred_cb_queue *, struct deferred_cb *);
michael@0: 
michael@0: #define LOCK_DEFERRED_QUEUE(q)						\
michael@0: 	EVLOCK_LOCK((q)->lock, 0)
michael@0: #define UNLOCK_DEFERRED_QUEUE(q)					\
michael@0: 	EVLOCK_UNLOCK((q)->lock, 0)
michael@0: 
michael@0: #ifdef __cplusplus
michael@0: }
michael@0: #endif
michael@0: 
michael@0: void event_deferred_cb_queue_init(struct deferred_cb_queue *);
michael@0: struct deferred_cb_queue *event_base_get_deferred_cb_queue(struct event_base *);
michael@0: 
michael@0: #endif /* _EVENT_INTERNAL_H_ */
michael@0: