POSIX does not require pthread_cond_wait to be interrupted by a signal; It does call a signal handler but can resume waiting, instead of returning to the caller as most other system calls. That makes implementing Schemel-evel thread-interrupt! difficult.
In Gauche, a Unix signal handler just records the signal delivery in a per-thread VM, and Scheme-level handler will be invoked later at the "safe" point of the VM. If a thread is waiting on pthread_cont_wait, however, it may not return after recording the signal delivery and may wait indefinitely. One possible strategy is that we always use pthread_cont_timedwait and let it timeout periodically to poll if a signal is delivered. It can be complicated if the Scheme program also sets a timeout, but doable. I wonder what other implementers think. On Fri, Nov 11, 2022 at 7:19 AM Marc Nieper-Wißkirchen < marc.nie...@gmail.com> wrote: > I have documented thread-interrupt! in 5.14.6. > > Thread-exit! is now renamed to thread-stop!. > > I hope that only editorial changes remain before we finalize this. >
