Re: [Libguestfs] [nbdkit PATCH v2 08/24] ocaml: Implement .cache script callback

On Wed, May 15, 2019 at 10:57:58PM -0500, Eric Blake wrote: > +static int > +can_cache_wrapper (void *h) > +{ > + CAMLparam0 (); > + CAMLlocal1 (rv); > + > + caml_leave_blocking_section (); > + > + rv = caml_callback_exn (can_cache_fn, *(value *) h); > + if (Is_exception_result (rv)) { > + nbdkit_error ("%s", caml_format_exception (Extract_exception (rv))); > + caml_enter_blocking_section (); > + CAMLreturnT (int, -1); > + } > + > + caml_enter_blocking_section (); > + CAMLreturnT (int, Int_val (rv)); The not very obvious implicit assumption here is that the order of the Cache* flags in the OCaml code is the same as the numbering of the NBDKIT_CACHE_* flags in the C code, which it is, so we should be good.