Hi Pavel Wow, I find this awesome. I don't have a Windows machine to play with, but I think I may have found something. The difference is how Java_sun_nio_ch_Net_poll is implemented. On unix it uses poll(2), on Windows it uses select(2). Regarding timeouts, poll() has "wait at least" semantics and overruns by design[1], while select() on windows has "waits at most" semantics, or how they put it[2]: "specifies the maximum time that select should wait before returning.". It returns early by design! Is this a known thing? I don't think there is much one can do here. It probably makes no sense to loop it and wait for time remainder. Java's soTimeout does not specify[3] should it wait at least or at most the specified timeout, so it's fine I guess. Old, "plain" socket impl are not much different.
If the above is correct, should I just add a tolerance for the lower bound? [1] http://man7.org/linux/man-pages/man2/poll.2.html [2] https://docs.microsoft.com/en-us/windows/win32/api/winsock2/nf-winsock2-select [3] https://docs.oracle.com/javase/9/docs/api/java/net/Socket.html#setSoTimeout-int- On Mon, 23 Sep 2019 at 16:15, Pavel Rappo <pavel.ra...@oracle.com> wrote: > > Milan, > > I'm observing the latest version (.04) of this test failing quite frequently > (4/100) on Windows (Windows Server 2012 R2 6.3 (amd64)) machines. The test > passes fine on macOS and Linux. Here's the typical output I see in the logs: > > java.lang.RuntimeException: Query took 4997 ms. . Timeout value is 5000 > java.lang.RuntimeException: Query took 4999 ms. . Timeout value is 5000 > java.lang.RuntimeException: Query took 4995 ms. . Timeout value is 5000 > java.lang.RuntimeException: Query took 4998 ms. . Timeout value is 5000 > ... > > Now, there might be many reasons for that. One of which would be that the > DnsClient code is buggy. The other reason would be that the accuracy > guaranteed by Windows implementation of `read` is not what we would expect. > Would you be able to investigate that? > > P.S. The good news is that the CSR has been approved: > > https://bugs.openjdk.java.net/browse/JDK-8230965 > > > On 23 Sep 2019, at 14:20, Milan Mimica <milan.mim...@gmail.com> wrote: > > > > Got it. Thanks Pavel! > > > > > > On Mon, 23 Sep 2019 at 13:37, Pavel Rappo <pavel.ra...@oracle.com> wrote: > >> > >> Milan, > >> > >> How do you check which tests are run? That's what I see in the > >> /test-support/jtreg_open_test_jdk_com_sun_jndi_dns_ConfigTests_TcpTimeout_java/com/sun/jndi/dns/ConfigTests/TcpTimeout.jtr > >> file after I have run the test locally on my machine: > >> > >> ----------messages:(5/233)---------- > >> command: main TcpTimeout > >> reason: User specified action: run main TcpTimeout > >> Mode: othervm > >> Additional options from @modules: --add-modules java.base --add-exports > >> java.base/sun.security.util=ALL-UNNAMED > >> elapsed time (seconds): 1.751 > >> > >> ... > >> > >> ----------messages:(5/313)---------- > >> command: main TcpTimeout -Dcom.sun.jndi.dns.timeout.initial=5000 > >> reason: User specified action: run main TcpTimeout > >> -Dcom.sun.jndi.dns.timeout.initial=5000 > >> Mode: othervm > >> Additional options from @modules: --add-modules java.base --add-exports > >> java.base/sun.security.util=ALL-UNNAMED > >> elapsed time (seconds): 5.498 > >> > >> ------------------------------------ > >> > >> Which is consistent with what I would expect given the timeout values. > >> > >> The following output does not tell the full story, just the name of the > >> test: > >> > >> ============================== > >> Test summary > >> ============================== > >> TEST TOTAL PASS FAIL ERROR > >> jtreg:open/test/jdk/com/sun/jndi/dns/ConfigTests/TcpTimeout.java > >> 1 1 0 0 > >> ============================== > >> TEST SUCCESS > >> > >> -Pavel > >> > >>> On 20 Sep 2019, at 15:42, Milan Mimica <milan.mim...@gmail.com> wrote: > >>> > >>> Pavel, > >>> > >>> Here it is: http://cr.openjdk.java.net/~mmimica/8228580/webrev.04/ > >>> I don't see the test is run twice when I execute "make test > >>> TEST=jtreg:test/jdk/com/sun/jndi/dns/ConfigTests/TcpTimeout.java". Am > >>> I missing something? > >>> > > > > > > -- > > Milan Mimica > -- Milan Mimica
