On 8/16/22 07:59, Dylan Yudaken wrote:
> Guard wakeups that the user can trigger, and that may end up triggering a
> call back into eventfd_signal. This is in addition to the current approach
> that only guards in eventfd_signal.
>
> Rename in_eventfd_signal -> in_eventfd at the same time to reflect this.
>
> Without this there would be a deadlock in the following code using libaio:
>
> int main()
> {
> struct io_context *ctx = NULL;
> struct iocb iocb;
> struct iocb *iocbs[] = { &iocb };
> int evfd;
> uint64_t val = 1;
>
> evfd = eventfd(0, EFD_CLOEXEC);
> assert(!io_setup(2, &ctx));
> io_prep_poll(&iocb, evfd, POLLIN);
> io_set_eventfd(&iocb, evfd);
> assert(1 == io_submit(ctx, 1, iocbs));
> write(evfd, &val, 8);
> }
Reviewed-by: Jens Axboe <axboe@xxxxxxxxx>
--
Jens Axboe
