RFR 8048193: [tests] Replace JPS and stdout based PID retrieval by Process.getPid()

[Staffan Larsen]

On 1 jul 2014, at 11:05, Jaroslav Bachorik <jaroslav.bachorik at oracle.com> wrote:

> On 07/01/2014 10:54 AM, Staffan Larsen wrote:
>> 
>> On 1 jul 2014, at 10:29, Jaroslav Bachorik <jaroslav.bachorik at oracle.com> wrote:
>> 
>>> On 07/01/2014 08:17 AM, Staffan Larsen wrote:
>>>> Jaroslav,
>>>> 
>>>> Great cleanup!
>>>> 
>>>> How about using Process.destroyForcibly() instead of sending the “shutdown” message? Maybe not as “nice”, but much less code.
>>> 
>>> The target process needs to hang around for a while till the test tries to shut it down. We would need to put a monitor wait there and rely on the OS being able to shut the process down.
>> 
>> Not sure what you mean. Why can’t we terminate the process at the same place we call RunnerUtil.stopApplication()?
> 
> The target application does nothing except of waiting to be shut down. It needs to hang around for the test to be able to attach to it. It used to listen on a socket to receive the shutdown message, now it reads from stdin to block and wait for shutdown. If the read from stdin is removed we would need to add another wait mechanism to make sure the application is alive until the test shuts it down.

Right. I would suggest a simple "for(;;) Thread.sleep(1000);” loop for this.

> 
>> 
>>> The Process.destroyForcibly() spec leaves it to the OS specific implementations to do the right thing. For the major OSes it seems to force kill the process but I'm not sure about eg. embedded devices.
>> 
>> I think the idea of Process.destroyForcibly() is that we /can/ rely on it. If we can’t rely on our own implementation, then the API is not very usable.
> 
> Might be the case -
> ...
> * The default implementation of this method invokes {@link #destroy}
> * and so may not forcibly terminate the process. Concrete implementations
> * of this class are strongly encouraged to override this method with a
> * compliant implementation.
> ...
> 
> If it can be confirmed that a process will always be forcibly destroyed I have nothing against using this API call instead of hand-crafting the shutdown mechanism.

All of the implementation of Process in the JDK do provide methods for forcibly terminating the process. The above reference to a default implementation is for allowing other Process implementation outside of the JDK. Our testing would never encounter those.

/Staffan

> 
> -JB-
> 
>> 
>>> 
>>>> 
>>>> test/sun/tools/jstatd/JstatdTest.java:
>>>>  323                     port = Integer.toString(31111); //Utils.getFreePort());
>>>>  Looks like a mistake?
>>> 
>>> Definitely a mistake :( Thanks for spotting it!
>>> 
>>> Updated webrev: http://cr.openjdk.java.net/~jbachorik/8048193/webrev.01
>> 
>> Looks good!
>> 
>> Thanks,
>> /Staffan
>> 
>> 
>>> 
>>> -JB-
>>> 
>>>> 
>>>> 
>>>> /Staffan
>>>> 
>>>> 
>>>> On 30 jun 2014, at 18:43, Jaroslav Bachorik <jaroslav.bachorik at oracle.com> wrote:
>>>> 
>>>>> Please, review the following test change.
>>>>> 
>>>>> Issue : https://bugs.openjdk.java.net/browse/JDK-8048193
>>>>> Webrev: http://cr.openjdk.java.net/~jbachorik/8048193/webrev.00
>>>>> 
>>>>> Intricate log parsing in order to get an application PID is replaced with the new Process.getPid() API call. While doing this cleanup it also become obvious that it was unnecessary to start a socket server for each launched test application just in order to shut it down when the same functionality can be achieved through the usage of stdin/stdout provided by the Process instance.
>>>>> 
>>>>> Thanks,
>>>>> 
>>>>> -JB-

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.openjdk.java.net/pipermail/serviceability-dev/attachments/20140701/09a76d55/attachment.html>