Handle EINTR during epoll_wait.

brettwooldridge / NuProcess

Low-overhead, non-blocking I/O, external Process implementation for Java

Apache License 2.0

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Handle EINTR during epoll_wait. #125

Closed bturner closed 2 years ago

bturner commented 3 years ago

epoll_wait is not restarted after it's interrupted by a signal handler, even if the handler used SA_RESTART. Instead, the calling code needs to handle the EINTR and restart the call itself.

Added logging in BaseEventProcessor and ProcessCompletions when the process() loop is aborted due to an exception
Added EINTR to LibC
Updated ProcessEpoll to detect EINTR after epoll_wait fails and return true to retry the call

Fixes #124

bturner commented 3 years ago

Seems like the CI bits aren't really running anymore. I don't see the ARM and x64 checks that other pull requests have had.

We were able to get a reproduction of EINTR by attaching strace to the JVM while it's in epoll_wait. Without this patch, an exception is thrown and the process is leaked. With it, processing continues normally.

bturner commented 3 years ago

I see 2.0.2 was released without this. Any chance of a merge and a 2.0.3?

bturner commented 3 years ago

We've found another path that can result in zombies. I'll either update this pull request or open a second one.