On Jan 17, 2008, at 8:12 AM, Joerg Heinicke wrote:
On 17.01.2008 05:45, Harald Entner wrote:
In normal mode everything runs fine. But when running a jmeter test
with 40 concurrent users, the AbstractWidgetDefinitionBuilder
throws a NullPointerException. see the full stacktrace at (1)
java.lang.NullPointerException
at
org
.apache
.cocoon
.forms
.formmodel
.AbstractWidgetDefinitionBuilder
.setupDefinition(AbstractWidgetDefinitionBuilder.java:109) (... see
1)
Probably the reason for this error is that the function
public WidgetDefinition buildWidgetDefinition(Element
widgetElement, WidgetDefinitionBuilderContext context)
throws Exception {
it is not thread-save.
I tried the same test with a little modification
(buildWidgetDefinition is synchronized)
public synchronized WidgetDefinition buildWidgetDefinition(Element
widgetElement, WidgetDefinitionBuilderContext context)
throws Exception {
The error (1) doesn't occur anymore, but another one: (see 2) It
seems that the cause for this is very similar to the one above.
Has one of you seen this error when running a stress test? What
could i do to avoid that problem? (i could go on and modify this
function to synchronized as well, but hopefully there is a better
solution for this. )
Hmm, this does not look good but like a major flaw in Cocoon Forms.
Following the Javadoc of WidgetDefinitionBuilder implementations of
this interface have to be thread-safe
Hmm, apparently intent does not match implementation.
- which they are not because of the context field. There is one
quick fix you can do: Make the context a ThreadLocal variable.
It has been fixed in trunk in r604025, but I did not notice that
javadoc snippet you pointed to.
Vadim
