RFR(s): 8212828: (process) Change the Process launch mechanism default on Linux to be posix_spawn

[Thomas Stüfe]

Hi Roger,

On Wed, Feb 6, 2019 at 4:15 PM Roger Riggs <Roger.Riggs at oracle.com> wrote:

> Hi Thomas,
>
> On 02/06/2019 04:29 AM, Thomas Stüfe wrote:
>
> Hi all
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8213192
> webrev:
> http://cr.openjdk.java.net/~stuefe/webrevs/8213192--(process)-change-the-process-launch-mechanism-default-on-linux-to-be-posix_spawn/webrev.00/webrev/index.html
>
>
> (@Roger: I hope you do not mind? The bug is assigned to you but since I
> happened to play around with posix_spawn I prepared this webrev. If you
> rather do this change, that is fine and I will leave it to you.)
>
> no problem, I hadn't gotten to it.  Thanks for proposing it.
>
>
> When we added the possibility to use posix_spawn as underlying
> implementation for Runtime.exec() on Linux with
> https://bugs.openjdk.java.net/browse/JDK-8212828, we agreed to keep VFORK
> as default until work on 13 starts. So now would be a good time to switch
> the default to posix_spawn to get a good testing window. Note that at SAP
> we run our VMs internally with posix_spawn as default since some months and
> have not seen problems.
>
> As for the fix, I added a test which tests that the default is indeed
> posix_spawn - not sure whether this is overdoing it though. Also, I use
> strace for the test, and /bin/true, and while strace is usually available
> and reachable by path resolution, I am afraid on some test machines it may
> not. What do you think, should I leave the test out?
>
> The test is a bit quirky but should work ok.
> I'd leave it in until it fails and re-evaluate then.
>
> If it fails on some systems, we can either configure them out or
> just skip the test if the process launch of strace fails.  (Throw
> SkippedException).
>
>
> Yes, that makes sense.


> The fix ran through all java/lang/ProcessBuilder jtreg tests ok.
>
> I'll run the patch through the usual CI build here too.
>
>
Thanks. I'll run the test thru the submit repository too.

Cheers, Thomas


> Thanks, Roger
>
>
> Thanks, Thomas
>
>
>