Date: Tue, 12 Feb 2013 09:46:40 +0200 From: Achilleas Mantzios <achill@smadev.internal.net> To: freebsd-java@freebsd.org Subject: Re: Problem with Java System.exit on OpenJDK 7 Message-ID: <1859971.L2l1UW0Dx7@smadev.internal.net> In-Reply-To: <CABBxOKm1zMiXNrU7Nm5ObcFdGb=7KobJfiLqJ4RtzjvrQbKbXA@mail.gmail.com> References: <CABBxOKm1zMiXNrU7Nm5ObcFdGb=7KobJfiLqJ4RtzjvrQbKbXA@mail.gmail.com>
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some suggestions/thoughts : - ktrace - truss - gdb against a _g version (debugging enabled) of OpenJDK 7 java (if available) - jdb I doubt KDE or anything would have any relation to your problem. It might more likely be related to libthr/libc What version of Java do you have on Windows? You have to realize jumping from Windows/(Oracle?)Java to FreeBSD/Openjdk7 makes a huge difference. Hmmmm this looks also like a TCP/IP timeout kind of thing... just a raw speculation. Can you try with disabling IPV6? On ÎÎµÏ 11 Φεβ 2013 17:15:23 David P. Caldwell wrote: > So I'm having a problem with the performance of a Java subprocess running > under Java, running on 9.0-RELEASE i386. > > It's a big subprocess, difficult to decompose. It's a big parent process, > difficult to decompose. I'm working on it. I've nearly ruled out the parent > process as the culprit (see below), but I include it for completeness, just > in case there's something I'm missing. > > Everything runs as expected on Windows, which brings me here to this list. > > Basically, the parent process launches the subprocess using a Java command. > It runs. It runs fine. The *subprocess* calls System.exit(0). That's where > the weirdness begins. > > System.exit(), for this program, takes about 2.6 seconds to run. And I > can't figure out why. It takes 0.025 seconds on Windows. > > The program is a command shell, essentially, so having every subshell add > 2.6 seconds of unnecessary execution time really slows things down. > > 1. The application has System.runFinalizersOnExit set to false; I checked > in java.lang.Shutdown using reflection to be sure. > > 2. The application, during its shutdown, has only one shutdown hook to run > -- the application shutdown hooks hook. That application shutdown hooks > hook has one hook, registered by me, which prints the timestamp (for trying > to debug this), only. Something takes 2.6 seconds to end the VM after this. > > 3. There are no temporary files to delete; I checked in > java.io.DeleteFilesOnExit using reflection to make sure. The system > registered shutdown hook in the slot for DeleteFilesOnExit is null. > > The problem appears to have nothing to do with the parent process. I > synthesized a giant command line command using the environment variables > and system properties under which the subprocess is running, and ran it > from the bash prompt, and still got the 2.6 second delay, based on running > the program inside a bash wrapper that first ran the subprocess giant > command, then printed the system time. I'm 99.9% ready to rule it out based > on that. > > During one experiment, when running the program twice on the same command > line, one of the runs, using the same command line, actually completed > System.exit in a time I'd expect -- about 0.03 seconds. The other took > about 2.6 seconds. All subsequent runs have take about two-and-a-half > seconds after the shutdown hooks; I haven't been able to reproduce the > success and I am quite sure I didn't change anything. > > I'm running this in a graphical terminal on KDE; haven't tried from an > ordinary console (obviously I am gradually broadening the things I'm doing, > so I'll probably get to that). The program is not graphical and presents no > GUI. > > The application does reference the standard input stream but the particular > program I was running consumes no input. It references stdout and stderr as > well, and is emitting output to those consoles. > > Does anyone have any idea or suggestions about where I should be looking at > this point? Obviously it's hard to instrument the program further on > FreeBSD -- I assume the NetBeans Profiler / jvisualvm stuff does not work > on FreeBSD; that's the last I heard. > _______________________________________________ > freebsd-java@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-java > To unsubscribe, send any mail to "freebsd-java-unsubscribe@freebsd.org" - Achilleas Mantzios IT DEV IT DEPT
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