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/*
* Copyright (C) 2012 Tobias Brunner
* Copyright (C) 2012 Giuliano Grassi
* Copyright (C) 2012 Ralf Sager
* Hochschule fuer Technik Rapperswil
*
* 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. See <http://www.fsf.org/copyleft/gpl.txt>.
*
* 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.
*/
/**
* @defgroup blocking_queue blocking_queue
* @{ @ingroup utils
*/
#ifndef BLOCKING_QUEUE_H_
#define BLOCKING_QUEUE_H_
typedef struct blocking_queue_t blocking_queue_t;
#include <library.h>
/**
* Class implementing a synchronized blocking queue based on linked_list_t
*/
struct blocking_queue_t {
/**
* Inserts a new item at the tail of the queue
*
* @param item item to insert in queue
*/
void (*enqueue)(blocking_queue_t *this, void *item);
/**
* Removes the first item in the queue and returns its value.
* If the queue is empty, this call blocks until a new item is inserted.
*
* @note This is a thread cancellation point
*
* @return removed item
*/
void *(*dequeue)(blocking_queue_t *this);
/**
* Destroys a blocking_queue_t object.
*
* @note No thread must wait in dequeue() when this function is called
*/
void (*destroy)(blocking_queue_t *this);
/**
* Destroys a queue and its objects using the given destructor.
*
* If a queue and the contained objects should be destroyed, use
* destroy_offset. The supplied offset specifies the destructor to
* call on each object. The offset may be calculated using the offsetof
* macro, e.g.: queue->destroy_offset(queue, offsetof(object_t, destroy));
*
* @note No thread must wait in dequeue() when this function is called
*
* @param offset offset of the objects destructor
*/
void (*destroy_offset)(blocking_queue_t *this, size_t offset);
/**
* Destroys a queue and its objects using a cleanup function.
*
* If a queue and its contents should get destroyed using a specific
* cleanup function, use destroy_function. This is useful when the
* list contains malloc()-ed blocks which should get freed,
* e.g.: queue->destroy_function(queue, free);
*
* @note No thread must wait in dequeue() when this function is called
*
* @param function function to call on each object
*/
void (*destroy_function)(blocking_queue_t *this, void (*)(void*));
};
/**
* Creates an empty queue object.
*
* @return blocking_queue_t object.
*/
blocking_queue_t *blocking_queue_create();
#endif /** BLOCKING_QUEUE_H_ @}*/
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