ConcurrentModificationException in ThreadProcessor

• Key: CAMEL-715
• Type: Bug
• Status: Resolved
• Resolution: Fixed
• Priority: Major
• Assignee: Willem Jiang
• Reporter: Wojciech Durczynski
• Component/s: camel-core
• Affects Version/s: 1.4.0
• Fix Version/s: 1.5.0

Description

When defining very simple routing with ThreadProcessor I get ConcurrentModificationException on multicore systems.

Example:
from("direct:a").thread(10).process(new Processor() {

@Override
public void process(Exchange ex) throws Exception { //sth }
});

Stack trace:
Exception in thread "Thread Processor"
java.util.ConcurrentModificationException
at java.util.HashMap$HashIterator.nextEntry(HashMap.java:793)
at java.util.HashMap$EntryIterator.next(HashMap.java:834)
at java.util.HashMap$EntryIterator.next(HashMap.java:832)
at java.util.HashMap.putAll(HashMap.java:523)
at
org.apache.camel.processor.Pipeline.createNextExchange(Pipeline.java:146
)
at org.apache.camel.processor.Pipeline$1.done(Pipeline.java:123)
at
org.apache.camel.processor.ThreadProcessor$ProcessCall.run(ThreadProcess
or.j
ava:66)
at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecuto
r.ja
va:885)
at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.ja
va:9
07)
at java.lang.Thread.run(Thread.java:619)

Comments

[Claus Ibsen]

Hi

Could you attach your sample that doesn't work on your system.

I have tried to create an unit test that demonstrates the bug but I runs fine here.

[Claus Ibsen]

And please provide us with information about OS: Camel Version, Java Version etc.

[Wojciech Durczynski]

JUnit test case that causes error

[Wojciech Durczynski]

Attached test case causes ConcurrentModificationException.
It happens on multicore machines only (always on quad core processor, never on single core)

Testing environment:
jdk 1.6.0_06
camel 1.4-SNAPSHOT
windows xp
eclipse 3.4

[Wojciech Durczynski]

Attachment without license

[Claus Ibsen]

Wojciech. Thanks for the test. It fails on my laptop as well.

However I must say though that such a scenario isn't really a real use-case. Who will fire 500000 messages simulationsly in one thread
But we will try to look into it.

[Willem Jiang]

http://svn.apache.org/viewvc?rev=679273&view=rev