Signal Handling in Oil

Handling signals in Python exposes you to EINTR.

See PEP 475 -- Retry system calls failing with EINTR. We're backporting this work. That's the main purpose of the native/posixmodule.c fork (in addition to removing over 7,000 lines of unused code).

Signals Oil cares about:

• SIGWINCH -- to get notified about Window size changes
• ... TODO

Relevant Files

• demo/eintr.sh in the repository

Difficulties With Signals In General

(This section isn't strictly related to Oil)

• Signals and multithreading
  • This blog post and related comments are confusing https://news.ycombinator.com/item?id=9564975
• API issues
  • Signals can be coalesced. e.g. When you get SIGCHLD, you have to call os.wait() multiple times to get multiple notifications. What about other signals?
  • Simultaneously waiting for both a signal and an event on a file descriptor. Solution: "the self-pipe trick".