RFR: 6402201: ProcessAttachTest.sh needs better synchronization

[Jaroslav Bachorik]

On 19.11.2013 09:45, Alan Bateman wrote:
> On 18/11/2013 23:29, Erik Gahlin wrote:
>> Could I have a review of this test fix.
>>
>> It appears it takes more than 10 s to write to a file on slow
>> machines. Instead of sleeping 10 s the test now polls for the file to
>> appear. There may be other issues with the test, but it's hard to know
>> without ruling this race out.
>>
>> Thanks
>> Erik
>>
>> Testing:
>> - I have run the test 20+ times locally on a highly saturated CPU
>> without failure
>> - JPRT.
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-6402201
>>
>> Webrev:
>> http://cr.openjdk.java.net/~egahlin/6402201_1/
> This looks okay to me. The only thing that comes to mind is whether it
> is possible for to observe the port file before the port is written.

I think it is. Writing to a file does not guarantee that it's creation 
and actual write are atomic :(

What I used to do was to write the data to one file and the use a second 
signaling file to notify the other party that the data has been 
successfully written and can be read.

-JB-

> Keeping the sleep so that it happens after you've file the file without
> significantly reduce that possibility.
>
> -Alan.