com.mchange.v1.lang.GentleThread Maven / Gradle / Ivy
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/*
* Distributed as part of c3p0 v.0.9.1.1
*
* Copyright (C) 2005 Machinery For Change, Inc.
*
* Author: Steve Waldman
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1, as
* published by the Free Software Foundation.
*
* This software 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this software; see the file LICENSE. If not, write to the
* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
* Boston, MA 02111-1307, USA.
*/
package com.mchange.v1.lang;
/**
* an abstract Thread class that provides
* utilities for easily defining Threads with
* safe versions of the deprecated thread
* methods stop(), resume(), and start()
*/
public abstract class GentleThread extends Thread
{
boolean should_stop = false;
boolean should_suspend = false;
public GentleThread()
{ super(); }
public GentleThread(String name)
{ super( name ); }
public abstract void run();
/**
* a safe method for stopping properly implemented GentleThreads
*/
public synchronized void gentleStop()
{should_stop = true;}
/**
* a safe method for suspending properly implemented GentleThreads
*/
public synchronized void gentleSuspend()
{should_suspend = true;}
/**
* a safe method for resuming properly implemented GentleThreads
*/
public synchronized void gentleResume()
{
should_suspend = false;
this.notifyAll();
}
/**
* tests whether the thread should stop.
* Subclasses should call this method periodically in
* their run method, and return from run() is the
* method returns true.
*/
protected synchronized boolean shouldStop()
{return should_stop;}
/**
* tests whether the thread should suspend.
* Subclasses rarely call this method directly,
* and should call allowSuspend() periodically
* instead.
*
* @see #allowSuspend
*/
protected synchronized boolean shouldSuspend()
{return should_suspend;}
/**
* tests whether the thread should suspend,
* and causes to the thread to pause if appropriate.
* Subclasses should call this method periodically
* in their run method to, um, allow suspension.
* Threads paused by allowSuspend() will be properly
* awoken by gentleResume()
*
* @see #gentleResume
*/
protected synchronized void allowSuspend() throws InterruptedException
{while (should_suspend) this.wait();}
}