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/*
 * Copyright (c) 2018-2020 "Graph Foundation,"
 * Graph Foundation, Inc. [https://graphfoundation.org]
 *
 * This file is part of ONgDB.
 *
 * ONgDB 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 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License
 * along with this program.  If not, see .
 */
/*
 * Copyright (c) 2002-2020 "Neo4j,"
 * Neo4j Sweden AB [http://neo4j.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j 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 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License
 * along with this program.  If not, see .
 */
package org.neo4j.scheduler;

import java.util.concurrent.Executor;
import java.util.concurrent.atomic.AtomicBoolean;

public class LockingExecutor implements Executor
{
    private final JobScheduler jobScheduler;
    private final JobScheduler.Group group;
    private final AtomicBoolean latch = new AtomicBoolean( false );

    public LockingExecutor( JobScheduler jobScheduler, JobScheduler.Group group )
    {
        this.jobScheduler = jobScheduler;
        this.group = group;
    }

    @Override
    public void execute( Runnable runnable )
    {
        if ( latch.compareAndSet( false, true ) )
        {
            jobScheduler.schedule( group, () ->
            {
                try
                {
                    runnable.run();
                }
                finally
                {
                    latch.set( false );
                }
            } );
        }
    }
}