On 5/10/05, Leszek Gawron <[EMAIL PROTECTED]> wrote:
Vadim Gritsenko wrote:
Leszek Gawron wrote:
Vadim Gritsenko wrote:
If you want to tinker with ContinuationsManagerImpl, take a look at: http://marc.theaimsgroup.com/?l=xml-cocoon-dev&m=111323704203839
Strange I missed that post ..
Unsynchronized access to WebContinuationsHolder from invalidateContinuations() simultaneously with write access in generateContinuation() should reliably cause ConcurrentModificationException.
I do not quite get the problem. Doesn't it cause ConcurrentModificationException now?
It should - I've not seen it though.
Other thing is how can invalidateContinuations and generateContinuation be run concurrently. invalidateContinuations is invoked only for expired sessions - how can new continuation be generated for that session?
Bad example then. Here is better one:
invalidateContinuations() gets Iterator on continuationsHolder.holder map. invalidateContinuations() calls _invalidate() _invalidate() calls disposeContinuation() disposeContinuation() modifies continuationsHolder.holder map.
After that,
invalidateContinuations() calls next() and causes ConcurrentModificationException.
Seems to me invalidateContinuations() should have while(!empty) loop instead of iterator.
Still HashMap has no interface other than iterator to get it's contents. you can either iterate through hashMap.iterator() or hashMap().keySet().iterator() - no difference, both are synced.
any ideas?
I've seen this problem with the 1.4.2_02 JDK, don't know if it exists elsewhere. The Sun docs claim syncrhonizing on the hashMap should solve the problem but it doesn't. The solution I came up with was to build an array instead of using an iterator, eg:
Object[] list = targetObjects.keySet().toArray();
Peter Hunsberger
I doubt it will work:
AbstractCollection.toArray() is in fact the implementation for HashMap.KeySet.toArray():
public Object[] toArray() {
Object[] result = new Object[size()];
Iterator e = iterator();
for (int i=0; e.hasNext(); i++)
result[i] = e.next();
return result;
}also uses iterator.
-- Leszek Gawron [EMAIL PROTECTED] IT Manager MobileBox sp. z o.o. +48 (61) 855 06 67 http://www.mobilebox.pl mobile: +48 (501) 720 812 fax: +48 (61) 853 29 65
