/*
* opencog/atoms/value/QueueValue.h
*
* Copyright (C) 2020 Linas Vepstas
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License v3 as
* published by the Free Software Foundation and including the exceptions
* at http://opencog.org/wiki/Licenses
*
* 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.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, write to:
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef _OPENCOG_QUEUE_VALUE_H
#define _OPENCOG_QUEUE_VALUE_H
#include <opencog/util/concurrent_queue.h>
#include <opencog/atoms/value/ContainerValue.h>
#include <opencog/atoms/atom_types/atom_types.h>
namespace opencog
{
/** \addtogroup grp_atomspace
* @{
*/
/**
* QueueValues provide a thread-safe FIFO queue of Values. They are
* meant to be used for producer-consumer APIs, where the produced
* values are to be handled in sequential order, in a different thread.
*/
class QueueValue
: public ContainerValue, protected concurrent_queue<ValuePtr>
{
protected:
QueueValue(Type t) : ContainerValue(t) {}
virtual void update() const;
public:
QueueValue(void) : ContainerValue(QUEUE_VALUE) {}
QueueValue(const ValueSeq&);
virtual ~QueueValue() {}
virtual void open(void);
virtual void close(void);
virtual bool is_closed(void) const;
virtual void add(const ValuePtr&);
virtual void add(ValuePtr&&);
virtual ValuePtr remove(void);
virtual size_t size(void) const;
virtual void clear(void);
};
VALUE_PTR_DECL(QueueValue);
CREATE_VALUE_DECL(QueueValue);
/** @}*/
} // namespace opencog
#endif // _OPENCOG_QUEUE_VALUE_H