Multirun

What's this?

This is a simplistic program that runs multiple copies of a single process, relaying signals received to its children, and managing cleanup. It was an exercise in learning the "selector" pattern in nim.

It is meant to be used in a daemontools pipeline.

If you need anything more complex, see foreman or one of its many clones. This tool is limited to doing only one thing with low resource usage.

Installation

You'll need a working Nim build environment. Simply run make release to build it. Put it wherever you please.

Usage

Options

• [-d|--debug]: Debug: Emit internal information to stderr.
• [-h|--help]: Help. You're lookin' at it.
• [-n|--number]: Number of children processes to execute. Defaults to the number of detected processors/cores.
• [-v|--version]: Display version number.

Example: multirun -n=12 program-to-run arguments

Notes

• Child processes emitting to stderr/stdout should be unbuffered.
• These signals are "gatewayed" to the child processes:
  • SIGHUP
  • SIGINT
  • SIGQUIT
  • SIGALRM
  • SIGTERM
  • SIGTSTP
  • SIGCONT
  • SIGUSR1
  • SIGUSR2
• Sending two consecutive TERM signals will force shutdown everything.
• The STOP signal is not catchable -- if you want to STOP and RESUME children, send TSTP instead. It has the same default effect.