From 9820962a9a0fb0fa9a49ddf49ee551ac41a708ae Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 24 Feb 2015 16:28:58 +0100
Subject: Switch to semaphore for signalling the mainloop to check for work

---
 .../org/openslx/taskmanager/main/Taskmanager.java  | 24 ++++++----------------
 1 file changed, 6 insertions(+), 18 deletions(-)

(limited to 'daemon/src')

diff --git a/daemon/src/main/java/org/openslx/taskmanager/main/Taskmanager.java b/daemon/src/main/java/org/openslx/taskmanager/main/Taskmanager.java
index f9b7752..1325dca 100644
--- a/daemon/src/main/java/org/openslx/taskmanager/main/Taskmanager.java
+++ b/daemon/src/main/java/org/openslx/taskmanager/main/Taskmanager.java
@@ -5,11 +5,9 @@ import java.util.Map;
 import java.util.concurrent.ArrayBlockingQueue;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.RejectedExecutionException;
+import java.util.concurrent.Semaphore;
 import java.util.concurrent.ThreadPoolExecutor;
 import java.util.concurrent.TimeUnit;
-import java.util.concurrent.locks.Condition;
-import java.util.concurrent.locks.Lock;
-import java.util.concurrent.locks.ReentrantLock;
 
 import org.apache.log4j.Logger;
 import org.openslx.taskmanager.Global;
@@ -46,8 +44,7 @@ public class Taskmanager implements FinishCallback, Runnable
 	 */
 	private final Map<String, AbstractTask> instances = new ConcurrentHashMap<>();
 
-	private final Lock workLock = new ReentrantLock();
-	private final Condition doCheckForWork = workLock.newCondition();
+	private final Semaphore doCheckForWork = new Semaphore( 0 );
 
 	/*
 	 * Static methods
@@ -142,12 +139,7 @@ public class Taskmanager implements FinishCallback, Runnable
 	 */
 	protected void checkForWork()
 	{
-		workLock.lock();
-		try {
-			doCheckForWork.signalAll();
-		} finally {
-			workLock.unlock();
-		}
+		doCheckForWork.release();
 	}
 
 	@Override
@@ -161,12 +153,8 @@ public class Taskmanager implements FinishCallback, Runnable
 	{
 		try {
 			while ( !Global.doShutdown ) {
-				workLock.lock();
-				try {
-					doCheckForWork.await( 1, TimeUnit.MINUTES );
-				} finally {
-					workLock.unlock();
-				}
+				doCheckForWork.tryAcquire( 1, TimeUnit.MINUTES );
+				doCheckForWork.drainPermits();
 				try {
 					for ( Iterator<AbstractTask> it = instances.values().iterator(); it.hasNext(); ) {
 						AbstractTask task = it.next();
@@ -176,8 +164,8 @@ public class Taskmanager implements FinishCallback, Runnable
 							continue;
 						}
 						if ( task.canStart() ) {
-							threadPool.execute( task );
 							log.debug( "Started Task " + task.getClass().getSimpleName() + " (" + task.getId() + ")" );
+							threadPool.execute( task );
 						}
 					}
 				} catch ( RejectedExecutionException e ) {
-- 
cgit v1.2.3-55-g7522