Eio_posix-based process runs into infinite loop after a few hours #495
Description
I have long-running server using Cohttp and Eio_posix (because so far it uses Eio_posix.Low_level.Process). Once in a while after a few hours of running fine it apparently randomly turns into an infinite loop using 100% of one CPU.
sudo strace -p <pid> says (thousands of lines like this per second):
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
[pid 3458264] rt_sigprocmask(SIG_BLOCK, NULL, [CHLD], 8) = 0
It's hard to reproduce reliably, let me know if there is anything I should to inspect the process better.