[infinispan-dev] JGroupsDistSync and ISPN-83

[Vladimir Blagojevic]

Manik (and others),

Can you run this code on your laptops and let me know what happened!

Vladimir

    public static void main (String [] arg) throws Exception {
       final JGroupsDistSync ds = new JGroupsDistSync();

       ds.acquireProcessingLock(false, 3, TimeUnit.SECONDS);
       System.out.println("Got read lock");

       Thread t = new Thread(){
         public void run (){
            try {
             ds.acquireProcessingLock(true, 3, TimeUnit.SECONDS);
             System.out.println("Got write lock");
          } catch (TimeoutException e) {
             System.out.println(e);
          }
         }
       };
       t.start();
    }



On 11-05-13 4:53 PM, Manik Surtani wrote:
> Yes, please have a look. If we are relying on lock upgrades then that's really bad. I am aware of the inability to (safely) upgrade a RWL and I'm pretty sure we don't try, but the dist sync codebase has evolved a lot and could do with some careful analysis.
>
> Sent from my mobile phone
>
> On 12 May 2011, at 09:24, Vladimir Blagojevic<vblagoje at redhat.com>  wrote:
>
>> On 11-05-11 11:23 AM, Dan Berindei wrote:
>>> If ReentrantReadWriteLock would allow upgrades then you would get a
>>> deadlock when two threads both hold the read lock and try to upgrade
>>> to a write lock at the same time.
>>> There's always a trade-off...
>>>
>>> I'm not familiar with the code, but are you sure the read lock is
>>> being held by the same thread that is trying to acquire the write
>>> lock?
>>>
>> Not sure and it sounds counter intuitive that a thread holding a read
>> lock from cluster invocation is doing state generation for state
>> transfer as well. But this lock business is fishy and I plan to get to
>> the bottom of it...
>>
>> _______________________________________________
>> infinispan-dev mailing list
>> infinispan-dev at lists.jboss.org
>> https://lists.jboss.org/mailman/listinfo/infinispan-dev
> _______________________________________________
> infinispan-dev mailing list
> infinispan-dev at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/infinispan-dev