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/*
* Copyright (C) 2012 Tobias Brunner
* Copyright (C) 2012 Giuliano Grassi
* Copyright (C) 2012 Ralf Sager
* HSR 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.
*/
#include "blocking_queue.h"
#include <threading/mutex.h>
#include <threading/thread.h>
#include <threading/condvar.h>
#include <collections/linked_list.h>
typedef struct private_blocking_queue_t private_blocking_queue_t;
/**
* Private data of a blocking_queue_t object.
*/
struct private_blocking_queue_t {
/**
* Public part
*/
blocking_queue_t public;
/**
* Linked list containing all items in the queue
*/
linked_list_t *list;
/**
* Mutex used to synchronize access to the queue
*/
mutex_t *mutex;
/**
* Condvar used to wait for items
*/
condvar_t *condvar;
};
METHOD(blocking_queue_t, enqueue, void,
private_blocking_queue_t *this, void *item)
{
this->mutex->lock(this->mutex);
this->list->insert_first(this->list, item);
this->condvar->signal(this->condvar);
this->mutex->unlock(this->mutex);
}
METHOD(blocking_queue_t, dequeue, void*,
private_blocking_queue_t *this)
{
bool oldstate;
void *item;
this->mutex->lock(this->mutex);
thread_cleanup_push((thread_cleanup_t)this->mutex->unlock, this->mutex);
/* ensure that a canceled thread does not dequeue any items */
thread_cancellation_point();
while (this->list->remove_last(this->list, &item) != SUCCESS)
{
oldstate = thread_cancelability(TRUE);
this->condvar->wait(this->condvar, this->mutex);
thread_cancelability(oldstate);
}
thread_cleanup_pop(TRUE);
return item;
}
METHOD(blocking_queue_t, destroy, void,
private_blocking_queue_t *this)
{
this->list->destroy(this->list);
this->condvar->destroy(this->condvar);
this->mutex->destroy(this->mutex);
free(this);
}
METHOD(blocking_queue_t, destroy_offset, void,
private_blocking_queue_t *this, size_t offset)
{
this->list->invoke_offset(this->list, offset);
destroy(this);
}
METHOD(blocking_queue_t, destroy_function, void,
private_blocking_queue_t *this, void (*fn)(void*))
{
this->list->invoke_function(this->list, (linked_list_invoke_t)fn);
destroy(this);
}
/*
* Described in header.
*/
blocking_queue_t *blocking_queue_create()
{
private_blocking_queue_t *this;
INIT(this,
.public = {
.enqueue = _enqueue,
.dequeue = _dequeue,
.destroy = _destroy,
.destroy_offset = _destroy_offset,
.destroy_function = _destroy_function,
},
.list = linked_list_create(),
.mutex = mutex_create(MUTEX_TYPE_DEFAULT),
.condvar = condvar_create(CONDVAR_TYPE_DEFAULT),
);
return &this->public;
}
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