tree 7c054589d6e20ee7a378be39788ef74edc707373
parent 7bd005ab1a76b9ffebc8bcdc179d4bc6f24354f9
author Adam Sadovsky <asadovsky@gmail.com> 1450815754 -0800
committer Adam Sadovsky <asadovsky@gmail.com> 1450815757 -0800

lib: gosh: "fix" the wait-signal race

Adjusts the gosh.Cmd API to deal with the race:
- Adds Cmd.{Signal,Kill} methods that handle the race
- Replaces Cmd.Process with Cmd.Pid, since clients should
  not do anything else with the Process handle

The race-handling logic hardcodes a particular internal
error message of the os package ("os: process already
finished"), which is brittle but seems more or less
unavoidable.

MultiPart: 1/2
Change-Id: I9cfb25bb09a3b88a69d596c092d1797d83bf3177