/*
* File : NonDaemonTaskRunner.java
* Created : 29-Dec-2003
* By : parg
*
* Azureus - a Java Bittorrent client
*
* This program 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 2 of the License.
*
* 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 ( see the LICENSE file ).
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
package org.gudy.azureus2.core3.util;
/**
* @author parg
*
*/
import java.util.*;
import org.gudy.azureus2.core3.logging.LogEvent;
import org.gudy.azureus2.core3.logging.LogIDs;
import org.gudy.azureus2.core3.logging.Logger;
public class
NonDaemonTaskRunner
{
public static final int LINGER_PERIOD = 2500;
protected static NonDaemonTaskRunner singleton;
protected static AEMonitor class_mon = new AEMonitor( "NonDaemonTaskRunner:class" );
protected Stack tasks = new Stack();
protected AEMonitor tasks_mon = new AEMonitor( "NonDaemonTaskRunner:tasks" );
protected AESemaphore task_sem = new AESemaphore("NonDaemonTaskRunner");
protected List wait_until_idle_list = new ArrayList();
protected AEThread2 current_thread;
protected static NonDaemonTaskRunner
getSingleton()
{
try{
class_mon.enter();
if ( singleton == null ){
singleton = new NonDaemonTaskRunner();
}
return( singleton );
}finally{
class_mon.exit();
}
}
public static Object
run(
NonDaemonTask target )
throws Throwable
{
return(getSingleton().runSupport( target, false ));
}
public static Object
runAsync(
NonDaemonTask target )
throws Throwable
{
return(getSingleton().runSupport( target, true ));
}
protected Object
runSupport(
NonDaemonTask target,
boolean async )
throws Throwable
{
// is this a recursive call? if so, run directly
if ( current_thread != null && current_thread.isCurrentThread()){
return( target.run());
}
taskWrapper wrapper = new taskWrapper( target );
try{
tasks_mon.enter();
tasks.push( wrapper );
task_sem.release();
if ( current_thread == null ){
final AESemaphore wait_sem = new AESemaphore("NonDaemonTaskRunnerTask: " + target.getName());
// NON-DAEMON!!!
current_thread =
new AEThread2( "NonDaemonTaskRunner", false )
{
public void
run()
{
wait_sem.release();
// System.out.println( "non daemon starts" );
while(true){
task_sem.reserve(LINGER_PERIOD);
taskWrapper t = null;
try{
tasks_mon.enter();
if ( tasks.isEmpty()){
current_thread = null;
for (int i=0;i<wait_until_idle_list.size();i++){
((AESemaphore)wait_until_idle_list.get(i)).release();
}
wait_until_idle_list.clear();
break;
}else{
t = (taskWrapper)tasks.pop();
}
}finally{
tasks_mon.exit();
}
t.run();
}
// System.out.println( "non daemon ends" );
}
};
current_thread.start();
wait_sem.reserve();
}
}finally{
tasks_mon.exit();
}
if ( async ){
return( null );
}
return( wrapper.waitForResult());
}
protected class
taskWrapper
{
protected NonDaemonTask task;
protected AESemaphore sem;
protected Object result;
protected Throwable exception;
protected
taskWrapper(
NonDaemonTask _task )
{
task = _task;
sem = new AESemaphore("NonDaemonTaskRunner::taskWrapper");
}
protected void
run()
{
try{
result = task.run();
}catch( Throwable e ){
exception = e;
}finally{
sem.release();
}
}
protected Object
waitForResult()
throws Throwable
{
sem.reserve();
if ( exception != null ){
throw( exception );
}
return( result );
}
}
public static void
waitUntilIdle()
{
getSingleton().waitUntilIdleSupport();
}
protected void
waitUntilIdleSupport()
{
AESemaphore sem;
try{
tasks_mon.enter();
if ( current_thread == null ){
return;
}
sem = new AESemaphore("NDTR::idleWaiter");
wait_until_idle_list.add( sem );
}finally{
tasks_mon.exit();
}
while( true ){
if ( sem.reserve( 10000 )){
break;
}
if (Logger.isEnabled()){
try{
tasks_mon.enter();
for (int i=0;i<wait_until_idle_list.size();i++){
AESemaphore pending = (AESemaphore)wait_until_idle_list.get(i);
if ( pending != sem ){
Logger.log(new LogEvent(LogIDs.CORE, "Waiting for " + pending.getName() + " to complete" ));
}
}
}finally{
tasks_mon.exit();
}
}
}
}
}