WebServer worker thread is stuck with on an incoming XML RPC call
-----------------------------------------------------------------
Key: XMLRPC-162
URL: https://issues.apache.org/jira/browse/XMLRPC-162
Project: XML-RPC
Issue Type: Bug
Affects Versions: 3.1.1
Environment: Linux on PPC - very slow CPU
Reporter: Mark Gertsvolf
I am running XML-RPC server on an underpowered Linux PPC box with JamVM or
Cacao, both use GNU classlib. This environment exposes a race condition in the
WebServer code.
Specificlly the issue is with how org.apache.xmlrpc.util.ThreadPool signals the
worker threads.
Poolable.startTask creates a new Poolable object and calls Poolable.start,
which sets the Poolable.task member and signals the thread encapsulated by
Poolable object. However, there is a potential race condition where the signal
can be lost if the encapsulated thread has just pased beyond the getTask check:
(line 55 trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java -
revision 720508)
The worker thread is suspended on wait and there is nobody to wake him up.
One way of fixing this issue is to add (getTask() == null) check inside the
synchronized block.
diff:
Index:
/var/opt/apachews/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
===================================================================
---
/var/opt/apachews/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
(revision 720508)
+++
/var/opt/apachews/trunk/common/src/main/java/org/apache/xmlrpc/util/ThreadPool.java
(working copy)
@@ -56,7 +56,9 @@
if (t == null) {
try {
synchronized (this) {
- wait();
+ if (!isShuttingDown() && getTask() ==
null) {
+ wait();
+ }
}
} catch (InterruptedException e) {
// Do nothing
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
