Date: Sat, 18 May 2013 22:23:25 -0700 From: Matt Birkholz <m...@birkholz.chandler.az.us>
If you are saying the library never has to block on any channels(?), then _progress_handler may do fine. It may even be acceptable if it blocks Scheme just a little(?). The sqlite3 progress mechanism is based on progress in executing a query, not anything to do with I/O. (Sqlite3 may block in I/O -- it repeats system calls on EINTR -- but except on remote file systems or screw cases like fifos, which are a bad idea for sqlite3 anyway, it shouldn't block for longer than the local disk's latency.) > The callback implementation I attached preserves the set of interrupts > enabled from C to the Scheme callback, Why do you mention this in particular? It seems odd. The enabled interrupts at the point of a callback are always /gc-ok. There is no point in saving them. Interrupts have to be saved/disabled before the preceding callout, else you will have holes. I mentioned it because you were worried about undesirable thread- switching in callbacks. If you disable thread timer interrupts on entry to the microcode, then this state will be preserved on entry to the Scheme callback, in order to avoid said thread-switching. For microcode primitives, it is not a priori the case that interrupts are disabled on entry. I will admit that I haven't looked very closely at your FFI's implementation. The magic happening in the macros is very hard to follow (C-INCLUDE, for example, expands to nothing -- it seems that you are abusing macros for side effects rather than expansion), and using it without installing things in $PREFIX/lib/mit-scheme-$ARCH doesn't seem to be supported. It's also not clear to me why Scheme needs to memorize so much information about the C platform's ABI (and the grovelling mechanism will get in the way of any attempt at cross- compilation), when you're already generating C code for the shims. _______________________________________________ MIT-Scheme-devel mailing list MIT-Scheme-devel@gnu.org https://lists.gnu.org/mailman/listinfo/mit-scheme-devel
