Hi Christoph, in general I think this is fine. The increase-by-pow2 sleep time is odd but okay :)
The whole things seems rather fragile and has a lot of question marks but I think your fix does not make it worse. One fun error now is that with a follow up java test reusing the PID we could get a wrong main class but I think the chances are astronomically low. Only remark, you fix this in the platform shared code, if this is a Linux only issue maybe it should be fixed in /shared/projects/openjdk/jdk-jdk/source/src/jdk.jcmd/linux/classes/sun/tools/ProcessHelper.java instead? If not, I would remove at least the /proc/<pid>/cmdline comment since this is quite platform specific. Cheers, Thomas On Wed, Sep 11, 2019 at 2:39 PM Langer, Christoph <christoph.lan...@sap.com> wrote: > Hi, > > > > please review this change for test sun/tools/jcmd/TestProcessHelper.java > to make it more robust. > > > > Bug: https://bugs.openjdk.java.net/browse/JDK-8230850 > > Webrev: http://cr.openjdk.java.net/~clanger/webrevs/8230850.0/ > > > > This Linux only test is starting several Java processes and then tries to > figure out the main class by invoking jdk.jcmd's linux specific > ProcessHelper implementation which parses the contents of > /proc/<pid>/cmdline. > > Under some circumstances, the test already attempts to read > /proc/<pid>/cmdline before it actually exists or is filled with data. This > can be fixed with some sleeps/retries to wait for that data to be ready. > > In the actual jcmd tool, such behavior of ProcessHelper. getMainClass > should not be an issue because it is handled in ProcessArgumentMatcher [0]. > > > > Thanks > > Christoph > > > > [0] > http://hg.openjdk.java.net/jdk/jdk/file/8b08eaf9a0eb/src/jdk.jcmd/share/classes/sun/tools/common/ProcessArgumentMatcher.java#l86 > > >
