From: Tim Pease <tim.pease@...>
Date: 2008-04-16T02:08:43+09:00
Subject: Re: at_exit handlers and Process.kill


On Apr 15, 2008, at 6:58 AM, Daniel Berger wrote:
> Hi all,
>
> Ruby 1.8.6 p114
> OS X 10.4
>
> None of these handlers get picked up when I kill the  
> 'process_test.rb' program with an external program. Why not?
>
> # process_test.rb
> File.open("pid.txt", "w"){ |fh| fh.print Process.pid }
> p Process.pid
>
> sleep 1 while true
>
> at_exit {
>   puts "AT_EXIT"
> }
>
> END{
>   puts "END"
> }
>
> trap("KILL"){
>   puts "KILLED"
> }
>
> # kill_test.rb
> pid = IO.read("pid.txt").to_i
> p pid
> Process.kill(5, pid)
>
> Dan
>

This works for me on OS 10.5.2 and ruby-1.8.6-p111

$ cat runner.rb
File.open('pid.txt', 'w') {|fd| fd.puts Process.pid}
puts Process.pid

at_exit {$stderr.puts "AT_EXIT"}
END {$stderr.puts "END"}
Signal.trap(5) {$stderr.puts "KILLED"}

loop {sleep 1}


$ cat killer.rb
pid = Integer(File.read('pid.txt'))
puts pid

Process.kill(5,pid)


And when I run the killer script the runner script dies and outputs  
"KILLED" to stderr.

The only real difference was using the explicit signal number (5) and  
putting the infinite sleep after all the exit handlers were  
registered. The only handler that was run was the block handling the  
trap. But the END block and the at_exit block were not run. I would  
expect that since a sigkill is pretty severe.

Blessings,
TwP