trap_exit cannot trap signal when exit/1 doesn't called explicitly
Wed Aug 23 09:03:59 CEST 2006
On 2006-08-22 18:22, lang er wrote:
> demonstrate_normal() ->
> demonstrate_exit(What) ->
> After start(), I call demonstrate_normal(), demo process should trap
> the exit(normal) signal, but it doesn't,
> and if I call demonstrate_exit(normal) , demo do trap the exit(normal).
> The only difference between theses two situations is the exiting process
> call exit/1 explicitly.
> Must I call exit before existing ?
''existing''? do you mean exiting :-)
you did not exit.
the shell is linked to the demo process when you call
demonstrate_normal(). but the shell never exits, so there is nothing to
trap for demo.
in demonstrate_exit() you do exit, and demo gets something.
(the shell is restarted after the exit).
EPO guidelines 1978: "If the contribution to the known art resides
solely in a computer program then the subject matter is not
patentable in whatever manner it may be presented in the claims."
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