Re: Re: Deadlock in oscache 2.0

Duh,

Looking at the Cache class a bit more closely, it looks like I need to
either call putInCache or cancelUpdate each time I call getFromCache.

I missed this note in the changes.txt  :(

- When a NeedsRefreshException is thrown, it is now vital that the cache
  entry is either updated, or Cache.cancelUpdate(key) is called to release
  the lock on this cache entry. This is a consequence of the fix for
  [CACHE-42].

Thanks,
Dave

On Sat, October 18, 2003 at 1:19 pm, David Rees sent the following
> Hi Chris,
>
> Found the issue and created a test case.
>
> The problem occurs when a NeedsRefreshException is thrown when calling
> getFromCache, but putInCache is not called with the sam key.  Then the
> next time getFromCache is called, it never returns as it still thinks that
> someone is waiting to update the cache entry.  Seems like a workaround
> would be to always attempt to insert something (even null?) when a
> NeedsRefreshException is called.
>
> I've attached a simple test case which shows the issue.
>
> -Dave
>
> On Sat, October 18, 2003 1at 1:06 am, Chris Miller sent the following
>> I checked in a fix for a deadlock problem a couple of days ago. The only
>> time it occurs is when there are more than two threads waiting on a new
>> cache entry to be built, AND you call cancelUpdate(). So give the
>> current
>> CVS head a try, if that still doesn't solve the problem then file a Jira
>> issue and I'll investigate further. If you still see deadlocks then a
>> test
>> case would be very helpful in tracking down the problem.
>>
>> (As an aside, there was a nasty threading problem in 1.7.5 that caused a
>> memory leak and gradual performance degradation, bear that in mind if
>> you
>> roll back to 1.7.5 in the meantime).
>>
>> Chris
>



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