Re: interrupting coroutines (was Re: Local Variables)

[Sean Conner <sean@...>]

It was thus said that the Great Roberto Ierusalimschy once stated:
> > > What is "gL" here?
> > 
> >   lua_State *gL;
> > 
> >   It's a C variable that is either global, or static to the file the
> > routines are defined in.
> 
> And where its value come from? (I thought the whole point of the
> discussion was how to access the *running* coroutine when a signal
> happens.)

  Could very well be.  I have the following Lua code:

	process = require "org.conman.process"
	signal  = require "org.conman.signal-posix" -- [1]

	function doit()
	  print("coroutine",coroutine.running())
	
	  signal.catch('xcpu',function(sig)
	    print("I have become bored!",coroutine.running())
	    os.exit(1)
	  end)

	  signal.catch('int',function(sig)
	    print("I am done with you!",coroutine.running())
	    os.exit(1)
	  end)
  
	  while true do
	  end
	end

	process.limits.hard.cpu = 3
	process.limits.soft.cpu = 2

Those last two lines limit the amount of time the script runs.  At 2
seconds, the system will send SIGXCPU; at 3, SIGKILL.  If I then have the
script do:

	doit()

the script outputs:

	coroutine       nil
	I have become bored!    nil

and yet, if I do:

	coroutine.resume(coroutine.create(function() doit() end))

	coroutine       thread: 0x23b1030
	Killed

which means SIGKILL was sent.  It's obvious that SIGXCPU was caught, but it
didn't run (or rather, something happened when I attempted to run the
registered Lua function).  Moving the signal.catch() calls out of the
function has the same results.

  -spc (Hmm ... perplexing ... )

[1]	https://github.com/spc476/lua-conmanorg/blob/master/src/signal-posix.c