On Tue, Jun 12, 2012 at 11:07 PM, Ángel González <[email protected]> wrote:
> On 11/06/12 23:12, Tom Boutell wrote:
>> Can you really use setjmp and longjmp in that way safely? I thought it
>> was only safe to longjmp "back," not "forward" - you can use them to
>> fake exception support but that's it because you'll smash the stack
>> otherwise. Something like that...
> My first reaction was also "How do you return to the mid-running function?"
>
> However, given that the running function is in PHP-land, I think you could
> (in non-zts, it's direct in zts), save EG() contents and replace with
> new values, and then continue the execution.
That's how it is currently implemented. The generator backs up the
current execution context (execute_data, CVs, Ts), pushed stack
arguments and several executor globals. When the generator is resumed
everything is restored and it continues to run as if nothing happened
:)
Doing context switching using setjmp family functions seems to me like
a really scary thing to do. I don't think that one can do that in a
sane way.
Nikita