Hi Thomas,
Yes, if there is no access to the pid, then it can't report alive or
not, and assume not.
If there access restrictions it will apply to the waitid/waitpid in the
waitForProcessExit0
logic also and the answer will be at least consistent (and avoid a
possible race
between //proc/pid/psinfo and kill state).
Thanks, Roger
On 7/18/2017 2:53 PM, Thomas Stüfe wrote:
Hi Roger,
I think this may fail if you have no permission to send a signal to
that process. In that case, kill(2) may yield EPERM and isAlive may
return false even though the process is alive.
But then, I am not sure if that could happen in that particular
scenario, plus it may also mean that you do not have access to
/proc/pid either. So, I do not know how much of an issue this could be.
Otherwise, the fix seems straightforward.
Kind Regards, Thomas
On Tue, Jul 18, 2017 at 8:46 PM, Roger Riggs <[email protected]
<mailto:[email protected]>> wrote:
Please review a fix for an intermittent failure in the
ProcessHandle OnExitTest
that fails frequently on Solaris.
ProcessHandle.isAlive is using /proc/pid/psinfo to determine if a
process is alive and it's start time.
However, it appears that the between the process exiting and the
reaping of its status, the
psinfo file indicates the process is alive but kill(pid, 0)
reports that is is not alive.
Depending on a race, the ProcessHandler.onExit may determine the
process has exited
but later isAlive may report it is alive.
To have a consistent view of the process being alive,
ProcessHandle.isAlive in its native implementation
should use kill(pid, 0) to determine if the process is
definitively determine if the process alive.
The original issue[1] will be kept open until it is known that it
is resolved.
Webrev:
http://cr.openjdk.java.net/~rriggs/webrev-alive-solaris-8184808/
<http://cr.openjdk.java.net/%7Erriggs/webrev-alive-solaris-8184808/>
Issue:
https://bugs.openjdk.java.net/browse/JDK-8184808
<https://bugs.openjdk.java.net/browse/JDK-8184808>
Thanks, Roger
[1] https://bugs.openjdk.java.net/browse/JDK-8177932
<https://bugs.openjdk.java.net/browse/JDK-8177932>
