Author: jochen
Date: Wed Apr 29 19:54:33 2009
New Revision: 769900
URL: http://svn.apache.org/viewvc?rev=769900&view=rev
Log:
PR: XMLRPC-168
Fixed a deadlock in the ThreadPool.
Modified:
webservices/xmlrpc/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
webservices/xmlrpc/trunk/src/changes/changes.xml
Modified:
webservices/xmlrpc/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
URL:
http://svn.apache.org/viewvc/webservices/xmlrpc/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java?rev=769900&r1=769899&r2=769900&view=diff
==============================================================================
---
webservices/xmlrpc/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
(original)
+++
webservices/xmlrpc/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
Wed Apr 29 19:54:33 2009
@@ -45,18 +45,18 @@
}
private class Poolable {
- private boolean shuttingDown;
+ private volatile boolean shuttingDown;
private Task task;
private Thread thread;
Poolable(ThreadGroup pGroup, int pNum) {
thread = new Thread(pGroup, pGroup.getName() + "-" + pNum){
public void run() {
- while (!isShuttingDown()) {
+ while (!shuttingDown) {
final Task t = getTask();
if (t == null) {
try {
synchronized (this) {
- if (!isShuttingDown() && getTask() ==
null) {
+ if (!shuttingDown && getTask() == null) {
wait();
}
}
@@ -69,7 +69,8 @@
resetTask();
repool(Poolable.this);
} catch (Throwable e) {
- discard(Poolable.this);
+ remove(Poolable.this);
+ Poolable.this.shutdown();
resetTask();
}
}
@@ -93,15 +94,13 @@
thread.notify();
}
}
- private synchronized boolean isShuttingDown() { return shuttingDown; }
- String getName() { return thread.getName(); }
- private synchronized Task getTask() {
+ private Task getTask() {
return task;
}
- private synchronized void resetTask() {
+ private void resetTask() {
task = null;
}
- synchronized void start(Task pTask) {
+ void start(Task pTask) {
task = pTask;
synchronized (thread) {
thread.notify();
@@ -126,26 +125,39 @@
threadGroup = new ThreadGroup(pName);
}
- synchronized void discard(Poolable pPoolable) {
- pPoolable.shutdown();
+ private synchronized void remove(Poolable pPoolable) {
runningThreads.remove(pPoolable);
waitingThreads.remove(pPoolable);
}
- synchronized void repool(Poolable pPoolable) {
- if (runningThreads.remove(pPoolable)) {
- if (maxSize != 0 && runningThreads.size() +
waitingThreads.size() >= maxSize) {
- discard(pPoolable);
- } else {
- waitingThreads.add(pPoolable);
- if (waitingTasks.size() > 0) {
- Task task = (Task) waitingTasks.remove(waitingTasks.size()
- 1);
- startTask(task);
- }
- }
- } else {
- discard(pPoolable);
- }
+ void repool(Poolable pPoolable) {
+ boolean discarding = false;
+ Task task = null;
+ Poolable poolable = null;
+ synchronized (this) {
+ if (runningThreads.remove(pPoolable)) {
+ if (maxSize != 0 && runningThreads.size() +
waitingThreads.size() >= maxSize) {
+ discarding = true;
+ } else {
+ waitingThreads.add(pPoolable);
+ if (waitingTasks.size() > 0) {
+ task = (Task)
waitingTasks.remove(waitingTasks.size() - 1);
+ poolable = getPoolable(task, false);
+ }
+ }
+ } else {
+ discarding = true;
+ }
+ if (discarding) {
+ remove(pPoolable);
+ }
+ }
+ if (poolable != null) {
+ poolable.start(task);
+ }
+ if (discarding) {
+ pPoolable.shutdown();
+ }
}
/** Starts a task immediately.
@@ -154,32 +166,45 @@
* the maxmimum number of concurrent tasks was exceeded. If so, you
* might consider to use the {...@link #addTask(ThreadPool.Task)}
method instead.
*/
- public synchronized boolean startTask(Task pTask) {
- if (maxSize != 0 && runningThreads.size() >= maxSize) {
- return false;
- }
- Poolable poolable;
- if (waitingThreads.size() > 0) {
- poolable = (Poolable)
waitingThreads.remove(waitingThreads.size()-1);
- } else {
- poolable = new Poolable(threadGroup, num++);
- }
- runningThreads.add(poolable);
- poolable.start(pTask);
+ public boolean startTask(Task pTask) {
+ final Poolable poolable = getPoolable(pTask, false);
+ if (poolable == null) {
+ return false;
+ }
+ poolable.start(pTask);
return true;
}
+ private synchronized Poolable getPoolable(Task pTask, boolean pQueue) {
+ if (maxSize != 0 && runningThreads.size() >= maxSize) {
+ if (pQueue) {
+ waitingTasks.add(pTask);
+ }
+ return null;
+ }
+ Poolable poolable;
+ if (waitingThreads.size() > 0) {
+ poolable = (Poolable)
waitingThreads.remove(waitingThreads.size()-1);
+ } else {
+ poolable = new Poolable(threadGroup, num++);
+ }
+ runningThreads.add(poolable);
+ return poolable;
+ }
+
/** Adds a task for immediate or deferred execution.
* @param pTask The task being added.
* @return True, if the task was started immediately. False, if
* the task will be executed later.
+ * @deprecated No longer in use.
*/
- public synchronized boolean addTask(Task pTask) {
- if (startTask(pTask)) {
- return true;
- }
- waitingTasks.add(pTask);
- return false;
+ public boolean addTask(Task pTask) {
+ final Poolable poolable = getPoolable(pTask, true);
+ if (poolable != null) {
+ poolable.start(pTask);
+ return true;
+ }
+ return false;
}
/** Closes the pool.
Modified: webservices/xmlrpc/trunk/src/changes/changes.xml
URL:
http://svn.apache.org/viewvc/webservices/xmlrpc/trunk/src/changes/changes.xml?rev=769900&r1=769899&r2=769900&view=diff
==============================================================================
--- webservices/xmlrpc/trunk/src/changes/changes.xml (original)
+++ webservices/xmlrpc/trunk/src/changes/changes.xml Wed Apr 29 19:54:33 2009
@@ -23,11 +23,14 @@
<title>Changes in Apache XML-RPC</title>
</properties>
<body>
- <release version="3.1.2" date="2009-Apr-19">
+ <release version="3.1.3-SNAPSHOT" date="2009-Apr-29">
<action dev="jochen" type="fix">
The version number in the clients user agent string is now
updated automatically.
</action>
+ <action dev="jochen" type="fix" issue="XMLRPC-168">
+ Fixed a deadlock in the ThreadPool.
+ </action>
</release>
<release version="3.1.2" date="2009-Apr-19">
