Waitpid equivalent with timeout?

Question

Imagine I have a process that starts several child processes. The parent needs to know when a child exits.

I can use waitpid, but then if/when the paren

Answer 1

I can use a signal handler for SIGCHLD, and in the signal handler do whatever I was going to do when a child exits, or send a message to a different thread to do some action. But using a signal handler obfuscates the flow of the code a little bit.

In order to avoid race conditions you should avoid doing anything more complex than changing a volatile flag in a signal handler.

I think the best option in your case is to send a signal to the parent. waitpid() will then set errno to EINTR and return. At this point you check for waitpid return value and errno, notice you have been sent a signal and take appropriate action.