RFR : 8038491: Improve synchronization in ZipFile.read()

[Seán Coffey]

This should make the code more robust Alan.

http://cr.openjdk.java.net/~coffeys/webrev.8038491.v3/webrev/

regards,
Sean.

On 09/04/2014 22:16, Alan Bateman wrote:
> On 09/04/2014 20:10, Seán Coffey wrote:
>>
>> I played around with adding some skip testing Alan but didn't see it 
>> increase the rate of failure on an unpatched binary. Since 
>> ZipFileInputStream.read(..) is the trouble method and now has better 
>> synchronized access to reading and updating rem, I believe we're 
>> good. skip(long) can trigger a close() but close() can't free up the 
>> resources without the ZipFile.this lock. As mentioned, having 
>> multiples threads reading from the one zip stream would make no sense 
>> anyhow.
>>
>> Let me know if I need to make changes. I don't think we want to add 
>> extra sync costs to the class.
> If you are only going to synchronize read then you will need to take a 
> copy of rem and pos, otherwise you have to assume that the check and 
> limiting of len isn't reliable, same thing for pos which could be way 
> out of range due to concurrent usages of skip.
>
> -Alan.