On 14/06/2022 10:44, Andrey Turbanov wrote:
Hello.
During investigation of signal handling in JVM (for
https://github.com/openjdk/jdk/pull/9100#discussion_r894992558 )
I found out that sending USR2 crashes my JDK. (Linux fastdebug x64)
kill -USR2 1346792
# assert(thread != __null) failed: Missing current thread in SR_handler
# Internal Error
(/home/turbanoff/Projects/official_jdk/src/hotspot/os/posix/signals_posix.cpp:1600),
pid=1346792, tid=1346792
Full hs_err_pid1346792.log:
https://gist.github.com/turbanoff/2099327ea13357a90df43a2d6b0e2e6a
Is it known/expected behaviour?
I found some description there
https://docs.oracle.com/en/java/javase/11/troubleshoot/handle-signals-and-exceptions.html
that USR2 is used for SUSPEND/RESUME. Is it supported by Hotspot?
In general you have to be very careful when using signals. Yes, it can
easily break things and probably notice it quickly with debug builds as
asserts are compiled in to the builds (like the above). So I think
you've found the right page to read up on this. In this case, you can
set _JAVA_SR_SIGNUM to specify a different signal for S/R.
-Alan
