Hi Matthias,
Thanks for cleaning this up.
On 19/09/2019 4:57 pm, Baesken, Matthias wrote:
Hello, as discussed below , I want to cleanup some older references to
sun.java.launcher.pid.
Please review the following change.
After removal of some code belonging old LinuxThreads (JDK-8078513) ,
the sun.java.launcher.pid handling code remained but
seems to be obsolete these days .
Bug/webrev :
https://bugs.openjdk.java.net/browse/JDK-8231171
http://cr.openjdk.java.net/~mbaesken/webrevs/8231171.0/
src/hotspot/os/bsd/os_bsd.cpp
Can you delete the entire comment block here:
1126 // Under the old bsd thread library, bsd gives each thread
...
1140 // OSThread::thread_id() method in osThread_bsd.hpp file
as it was simply copied from Linux and is nonsense on BSD.
Otherwise that all looks good to me. No need for an updated webrev.
Thanks,
David
-----
Best regards, Matthias
Hi David, thanks for the additional information .
I opened
https://bugs.openjdk.java.net/browse/JDK-8231171
8231171: remove reamining sun.java.launcher.pid references
to do the additional cleanup .
Best regards, Matthias
-----Original Message-----
From: David Holmes <[email protected]>
Sent: Mittwoch, 18. September 2019 03:16
To: Baesken, Matthias <[email protected]>; 'hotspot-
[email protected]' <[email protected]>
Subject: Re: sun.java.launcher.pid property usage
Hi Matthias,
On 18/09/2019 12:18 am, Baesken, Matthias wrote:
Hello, while looking at some atoi usages in the codebase I started to
wonder about the "sun.java.launcher.pid" property.
Currently in java_md_solinux.c the property is set on Linux only by
default
(code is guarded #ifdef __linux__ ).
Later it is passed to the int variable _sun_java_launcher_pid
(arguments.cpp) and can be retrieved by sun_java_launcher_pid() .
However only in src/hotspot/os/bsd/os_bsd.cpp it is really used.
Is the property still supported (one would need to set it from user side on
the command line on non-Linux because it is not set by default on
bsd/macOS) ?
Can the coding be removed (or should it enabled for BSD/Mac like we do
on Linux) ?
The os_bsd comment mentiones the bug 6351349 :
https://bugs.java.com/bugdatabase/view_bug.do?bug_id=6351349
JDK-6351349 : On linux with the old thread lib, jps should return the same
PID as $!
but this looks very old.
That was the bug that added this code as it was needed on Linux with
LinuxThreads. The code was then removed on Linux under
https://bugs.openjdk.java.net/browse/JDK-8078513
The review thread starts here:
http://mail.openjdk.java.net/pipermail/hotspot-runtime-dev/2015-
May/014709.html
I think we were focussed solely on cleaning up the hotspot Linux code
and didn't really look at the wider implication of the use of
sun.java.launcher.pid. The code in os_bsd.cpp was simply copied from the
Linux code without giving it any consideration - as you can tell from
the comment:
// With BsdThreads the JavaMain thread pid (primordial thread)
// is different than the pid of the java launcher thread.
// So, on Bsd, the launcher thread pid is passed to the VM
// via the sun.java.launcher.pid property.
where you can tell that Linux was simply replaced by Bsd, so we
reference the non-existent BsdThreads :(
So yes this all seems to be dead code that should be removed - core-libs
folk will need to be involved of course as they own the launcher. :) It
looks like SetJavaLauncherPlatformProps() can be removed completely.
Thanks,
David
