From: dsh0416@... Date: 2020-08-16T01:12:32+00:00 Subject: [ruby-core:99600] [Ruby master Feature#17059] epoll as the backend of IO.select on Linux Issue #17059 has been updated by dsh0416 (Delton Ding). It should greatly improve the performance. Advanced registration is a feature of `epoll`, but the performance is also an important part for it. The benchmark from libevent shows the performance of epoll and poll or select, are on a totally different stage. So this may be important to performance. ---------------------------------------- Feature #17059: epoll as the backend of IO.select on Linux https://bugs.ruby-lang.org/issues/17059#change-87079 * Author: dsh0416 (Delton Ding) * Status: Open * Priority: Normal ---------------------------------------- Current Ruby's `IO.select` method calls POSIX `select` API directly. With the new non-blocking scheduler, this may be the bottleneck of the I/O scheduling. For keeping the backward compatibilty of the current `IO.select` methods, a proposal may be to create a "duck" `select` which uses the `epoll_wait` as the backend. One tricky part is that the `fd_set` described in POSIX is write-only, which means it is impossible to iterate for generating the `epoll_event` argument for `epoll_wait`. But similar to the large-size select situation, we could define our own `rb_fdset_t` struct in this case, and implement the following APIs. ``` void rb_fd_init(rb_fdset_t *); void rb_fd_term(rb_fdset_t *); void rb_fd_zero(rb_fdset_t *); void rb_fd_set(int, rb_fdset_t *); void rb_fd_clr(int, rb_fdset_t *); int rb_fd_isset(int, const rb_fdset_t *); void rb_fd_copy(rb_fdset_t *, const fd_set *, int); void rb_fd_dup(rb_fdset_t *dst, const rb_fdset_t *src); int rb_fd_select(int, rb_fdset_t *, rb_fdset_t *, rb_fdset_t *, struct timeval *); ``` TODO: 1. Implement the fd_set with dynamic allocated fds. 2. Implement the epoll with select API. 3. Edit io.c to use the customized fd_set struct. I'm trying to work on a branch for this. Any suggestions for this? ---Files-------------------------------- epoll.h (3.62 KB) -- https://bugs.ruby-lang.org/ Unsubscribe: