src/main/activemq/util/MemoryUsage.h

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _ACTIVEMQ_UTIL_MEMORYUSAGE_H_
#define _ACTIVEMQ_UTIL_MEMORYUSAGE_H_

#include <activemq/util/Config.h>
#include <activemq/util/Usage.h>
#include <decaf/util/concurrent/Mutex.h>

namespace activemq {
namespace util {

    class AMQCPP_API MemoryUsage : public Usage {
    private:

        // The physical limit of memory usage this object allows.
        unsigned long long limit;

        // Amount of memory currently used in.
        unsigned long long usage;

        // Mutex to lock usage and wait on.
        mutable decaf::util::concurrent::Mutex mutex;

    public:

        MemoryUsage();

        MemoryUsage( unsigned long long limit );

        virtual ~MemoryUsage();

        virtual void waitForSpace();

        virtual void waitForSpace( unsigned int timeout );

        virtual void enqueueUsage( unsigned long long value ) {
            waitForSpace();
            increaseUsage(value);
        }

        virtual void increaseUsage( unsigned long long value );

        virtual void decreaseUsage( unsigned long long value );

        virtual bool isFull() const;

        unsigned long long getUsage() const {
            return usage;
        }

        void setUsage( unsigned long long usage ) {
            this->usage = usage;
        }

        unsigned long long getLimit() const {
            return limit;
        }

        void setLimit( unsigned long long limit ) {
            this->limit = limit;
        }

    };

}}

#endif /*_ACTIVEMQ_UTIL_MEMORYUSAGE_H_*/