- what are signals
- interruptible / noninterruptible / recursive
- example with problems
  - lock
  - errno
  - fprintf
  - malloc
- safe signal handling
  - async signal safe functions
  - blocking signals
  - no / controlled shared state:
    - no locks
    - reentrancy
- what signals exists commonly
- which signals does postgres use
- well, you say signal handers suck, what now?
- latches
- procsignals