Process API Updates (JEP 102) (original) (raw)

Roger Riggs Roger.Riggs at Oracle.com
Wed Mar 26 00:27:01 UTC 2014

Hi Florian,

On 3/25/14 5:18 AM, Florian Weimer wrote:

On 03/24/2014 10:11 PM, roger riggs wrote:

From the scope of the JEP, a fairly simple API seems sufficient. - Enumerate the direct children - The rest of the functions are similar to Process - to terminate a process, forcibly and normally - to destroy a process and all of its children recursively - to check if one is alive - to waitFor for termination and retrieve the exit status On Linux, I think you need to use obscure mechanisms to make this iteration reliable (cgroups perhaps). There is no openpid() or similar mechanism that allows you to obtain a stable handle. Given that processes are asynchronous in creation and termination, I don't think 'reliable' listing is possible. In a pathological case, processes can be created as fast/faster than they can be terminated. Somewhat relatedly, it would make sense to make Process auto-closeable, so that you can make sure that no non-Java resources are retained. Right now, this seems to require calling destroyForcibly().waitFor(). That's worth looking at a close() method could have that compound behavior. It would be nice if there was a way to directly pipe the output of one process to the input of another process. I think that even with Java 8, this still needs an explicit copy loop. That's similar to other requests to directly feed or consume from the subprocess from a file or pipe.

Thanks, Roger

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