Hi Thomas,
On 4/17/2015 4:22 AM, Thomas Stüfe wrote:
Hi Roger,
aside from the recycle-pid-question, one additional remark:
in ProcessHandleImpl_unix.c,
Java_java_lang_ProcessHandleImpl_isAlive0, you call kill(pid, 0) for
the liveness check.
If you have not the necessary permissions to do this call, this may
fail with EPERM. In this case, isAlive() will return false, but the
process exists, which strictly spoken is a lie.
Caller may base actions on this, e.g. try to clean up resources for a
process he thinks is dead.
We actually had this problem, and our version of isAlive() grew to be
more elaborate over time. Basically, we do:
1) first try kill(0). If EPERM:
2) try read /proc on OSes which have /proc.
3) do a system("ps").
Alternativly, one may report EPERM to the caller - with an exception
or an extension of the return value - and leave it up to him what to do.
Good to have the experienced input. I'd been trying to keep the code
simple but it seems
more complexity is needed to be robust. I'm not sure I'd go as far as
invoking ps; it too might
fail for a number of reasons. That would be a good case to throw an
exception if the liveness
cannot be determined.
Thanks, Roger
Kind Regards, Thomas
On Thu, Apr 9, 2015 at 10:00 PM, Roger Riggs <roger.ri...@oracle.com
<mailto:roger.ri...@oracle.com>> wrote:
Please review the API and implementation of the Process API Updates
described inJEP 102
<https://bugs.openjdk.java.net/browse/JDK-8046092>. Please review
and comment by April 23rd.
The recommendation to make ProcessHandle an interface is included
allowing the new functions to be extended by Process subclasses.
The implementation covers all functions on Unix, Windows, Solaris,
and Mac OS X.
The API doc: http://cr.openjdk.java.net/~rriggs/ph-apidraft/
<http://cr.openjdk.java.net/%7Erriggs/ph-apidraft/>
The webrev: http://cr.openjdk.java.net/~rriggs/webrev-ph
<http://cr.openjdk.java.net/%7Erriggs/webrev-ph>
Issue: JDK-8077350
<https://bugs.openjdk.java.net/browse/JDK-8077350> Process API
Updates Implementation
The code is in the jdk9 sandbox on branch JDK-8046092-branch.
Please review and comment, Roger
