TemporaryAccountWorker.java
/*
** Module : TemporaryAccountWorker.java
** Abstract : a Runnable object used to manage user accounts.
**
** Copyright (c) 2013-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- -------------------------------Description------------------------------------
** 001 MAG 20131216 Created initial version.
** 002 CA 20140214 Fixed NPE at thread shutdown when the pool is never used.
** 003 MAG 20140217 Fixed thread termination.
** 004 CA 20150909 Fixed a race condition resulting in a NPE for callerLatch.
** 005 GBB 20230512 Logging methods replaced by CentralLogger/ConversionStatus.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero 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 Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
**
** Additional terms under GNU Affero GPL version 3 section 7:
**
** Under Section 7 of the GNU Affero GPL version 3, the following additional
** terms apply to the works covered under the License. These additional terms
** are non-permissive additional terms allowed under Section 7 of the GNU
** Affero GPL version 3 and may not be removed by you.
**
** 0. Attribution Requirement.
**
** You must preserve all legal notices or author attributions in the covered
** work or Appropriate Legal Notices displayed by works containing the covered
** work. You may not remove from the covered work any author or developer
** credit already included within the covered work.
**
** 1. No License To Use Trademarks.
**
** This license does not grant any license or rights to use the trademarks
** Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
** of Golden Code Development Corporation. You are not authorized to use the
** name Golden Code, FWD, or the names of any author or contributor, for
** publicity purposes without written authorization.
**
** 2. No Misrepresentation of Affiliation.
**
** You may not represent yourself as Golden Code Development Corporation or FWD.
**
** You may not represent yourself for publicity purposes as associated with
** Golden Code Development Corporation, FWD, or any author or contributor to
** the covered work, without written authorization.
**
** 3. No Misrepresentation of Source or Origin.
**
** You may not represent the covered work as solely your work. All modified
** versions of the covered work must be marked in a reasonable way to make it
** clear that the modified work is not originating from Golden Code Development
** Corporation or FWD. All modified versions must contain the notices of
** attribution required in this license.
*/
package com.goldencode.p2j.main;
import java.util.concurrent.*;
import java.util.logging.*;
import com.goldencode.p2j.util.logging.*;
/**
* A Runnable object used to manage user accounts.
* In order to manage user account admin rights are mandatory.
* This object is used as Runnable target in an AssociatedThread instance
* which run in standard server security context and inherit server admin rights.
* This object execute the run method of another Runnable object the task to be executed.
* The execute method is synchronized between this thread and caller.
* The caller waits for end of execution of task that he provide as parameter.
*
* @author mag
*
*/
public class TemporaryAccountWorker
implements Runnable
{
/** Logger. */
private static final CentralLogger LOG = CentralLogger.get(TemporaryAccountWorker.class.getName());
/** Termination flag */
private volatile boolean terminated = false;
/** Thread synchronization */
private volatile CountDownLatch workerLatch;
/** Caller synchronization */
private volatile CountDownLatch callerLatch;
/** Task to be executed */
private volatile Runnable task;
/**
* Constructor.
* Initialize thread synchronization latch.
*/
public TemporaryAccountWorker()
{
workerLatch = new CountDownLatch(1);
}
/**
* Execute specified task.
*
* @param task
* Task to be executed.
*/
public void execute(Runnable task)
{
try
{
if (!terminated)
{
// Set task instance.
this.task = task;
// Arm caller latch.
callerLatch = new CountDownLatch(1);
// Execute task.
workerLatch.countDown();
// Wait for task execution to end.
callerLatch.await();
}
}
catch (InterruptedException e)
{
LOG.logp(Level.WARNING,
"TemporaryAccountWorker.execute()",
"",
"InterruptedException!",
e);
}
}
/**
* Task executor.
*/
public void run()
{
while (!terminated)
{
try
{
// Waiting for a call
workerLatch.await();
// Execute task
if (!terminated && task != null)
{
task.run();
task = null;
}
}
catch (InterruptedException e)
{
LOG.logp(Level.WARNING,
"TemporaryAccountWorker.run()",
"",
"InterruptedException!",
e);
}
finally
{
if (!terminated && workerLatch.getCount() == 0)
{
workerLatch = new CountDownLatch(1);
}
if (callerLatch != null && callerLatch.getCount() == 1)
{
// Notify caller
callerLatch.countDown();
}
}
}
LOG.logp(Level.INFO,
"TemporaryAccountWorker.run()",
"",
"Thread exit.");
}
/**
* Terminate thread.
*/
public void terminate()
{
this.terminated = true;
if (workerLatch.getCount() == 1)
{
workerLatch.countDown();
}
}
}