I think you want with-handler*? According to the docs: with-handlers:
Before any predicate or handler procedure is invoked, the continuation of the entire with-handlers <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29> expression is restored, but also parameterize-break <https://docs.racket-lang.org/reference/breakhandler.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._parameterize-break%29%29>ed to disable breaks. Thus, breaks are disabled by default during the predicate and handler procedures (see Breaks <https://docs.racket-lang.org/reference/breakhandler.html>), and the exception handler is the one from the continuation of the with-handlers <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29> expression. with-handler* Like with-handlers <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%29%29>, but if a handler-expr procedure is called, breaks are not explicitly disabled, and the handler call is in tail position with respect to the with-handlers* <https://docs.racket-lang.org/reference/exns.html#%28form._%28%28lib._racket%2Fprivate%2Fmore-scheme..rkt%29._with-handlers%2A%29%29> form. On Thu, Oct 7, 2021 at 5:36 PM 'William J. Bowman' via Racket Users < [email protected]> wrote: > I have a little model of a server below. The server handles all > exceptions, and restarts itself after some errors. It also handles break?, > to actually exit when requested. > > While this server is running, if I press Ctrl+C before `(error 'foo)` is > handled, the server exits correctly with 120. However, if I press Ctrl+C > after `(error 'foo)` is handled, the `exn:break?` handler is never called, > the server no longer responds to `Ctrl+C`, and (in this example) it > eventually exits with status `1`. > > I cannot figure out why. As far as I can tell, this should always handle > `Ctrl+C` by exiting with 120. > > > #lang racket/base > > > > (let loop ([n 0]) > > (with-handlers ([exn:break? (lambda _ (exit 120))] > > [void > > (lambda (exn) > > (printf "handled error: ~a~n" (exn-message exn)) > > (loop (add1 n)))]) > > (displayln n) > > (sleep 1) > > (cond > > [(zero? n) (error 'foo)] > > [(= n 5) (exit 1)]) > > (loop (add1 n)))) > > -- > William J. Bowman > > -- > You received this message because you are subscribed to the Google Groups > "Racket Users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-users/YV%2BSWNpldfOB5tA3%40williamjbowman.com > . > -- You received this message because you are subscribed to the Google Groups "Racket Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-users/CADcuegvKwRkOuC_3nQ4UqWFVK2kac1nCgucYuFz%2BD%2BRJnD0kNg%40mail.gmail.com.
