From 2f248f91ee72fc0cdbe0ca50ea1a3116cf11e8ca Mon Sep 17 00:00:00 2001
From: Jean Boussier <jean.boussier@gmail.com>
Date: Wed, 6 Mar 2024 13:29:10 -0500
Subject: [PATCH] Fix Ruby 3.4-dev compatibility

---
 CHANGELOG.md                        |  2 ++
 Gemfile.lock                        |  3 +--
 ext/pitchfork_http/epollexclusive.h | 22 +++++++++++++++-------
 ext/pitchfork_http/extconf.rb       |  2 ++
 4 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6f5705f5..b476b78f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Unreleased
 
+- Fix Ruby 3.4-dev compatibility.
+
 # 0.11.0
 
 - Drop invalid response headers.
diff --git a/Gemfile.lock b/Gemfile.lock
index 1740894d..3a71cf2e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -20,8 +20,7 @@ GEM
 
 PLATFORMS
   aarch64-linux
-  arm64-darwin-21
-  arm64-darwin-22
+  arm64-darwin
   x86_64-linux
 
 DEPENDENCIES
diff --git a/ext/pitchfork_http/epollexclusive.h b/ext/pitchfork_http/epollexclusive.h
index cc051ac4..c38404b6 100644
--- a/ext/pitchfork_http/epollexclusive.h
+++ b/ext/pitchfork_http/epollexclusive.h
@@ -21,6 +21,16 @@
 #  define USE_EPOLL (0)
 #endif
 
+#ifndef HAVE_RB_IO_DESCRIPTOR /* Ruby < 3.1 */
+static int rb_io_descriptor(VALUE io)
+{
+    rb_io_t *fptr;
+    GetOpenFile(io, fptr);
+    rb_io_check_closed(fptr);
+    return fptr->fd;
+}
+#endif
+
 #if USE_EPOLL
 /*
  * :nodoc:
@@ -54,8 +64,7 @@ static VALUE prep_readers(VALUE cls, VALUE readers)
 		 */
 		e.events = EPOLLEXCLUSIVE | EPOLLIN;
 		io = rb_io_get_io(io);
-		GetOpenFile(io, fptr);
-		rc = epoll_ctl(epfd, EPOLL_CTL_ADD, fptr->fd, &e);
+		rc = epoll_ctl(epfd, EPOLL_CTL_ADD, rb_io_descriptor(io), &e);
 		if (rc < 0) rb_sys_fail("epoll_ctl");
 	}
 	return epio;
@@ -65,7 +74,7 @@ static VALUE prep_readers(VALUE cls, VALUE readers)
 #if USE_EPOLL
 struct ep_wait {
 	struct epoll_event event;
-	rb_io_t *fptr;
+	VALUE io;
 	int timeout_msec;
 };
 
@@ -79,7 +88,7 @@ static void *do_wait(void *ptr) /* runs w/o GVL */
 	 * at-a-time (c.f. fs/eventpoll.c in linux.git, it's quite
 	 * easy-to-understand for anybody familiar with Ruby C).
 	 */
-	return (void *)(long)epoll_wait(epw->fptr->fd, &epw->event, 1,
+	return (void *)(long)epoll_wait(rb_io_descriptor(epw->io), &epw->event, 1,
 					epw->timeout_msec);
 }
 
@@ -93,11 +102,10 @@ get_readers(VALUE epio, VALUE ready, VALUE readers, VALUE timeout_msec)
 
 	Check_Type(ready, T_ARRAY);
 	Check_Type(readers, T_ARRAY);
-	epio = rb_io_get_io(epio);
-	GetOpenFile(epio, epw.fptr);
-
+	epw.io = rb_io_get_io(epio);
 	epw.timeout_msec = NUM2INT(timeout_msec);
 	n = (long)rb_thread_call_without_gvl(do_wait, &epw, RUBY_UBF_IO, NULL);
+	RB_GC_GUARD(epw.io);
 	if (n < 0) {
 		if (errno != EINTR) rb_sys_fail("epoll_wait");
 	} else if (n > 0) { /* maxevents is hardcoded to 1 */
diff --git a/ext/pitchfork_http/extconf.rb b/ext/pitchfork_http/extconf.rb
index 939cfe4b..5ed2b562 100644
--- a/ext/pitchfork_http/extconf.rb
+++ b/ext/pitchfork_http/extconf.rb
@@ -3,6 +3,8 @@
 
 have_const("PR_SET_CHILD_SUBREAPER", "sys/prctl.h")
 have_func("rb_enc_interned_str", "ruby.h") # Ruby 3.0+
+have_func("rb_io_descriptor", "ruby.h") # Ruby 3.1+
+
 if RUBY_VERSION.start_with?('3.0.')
   # https://bugs.ruby-lang.org/issues/18772
   $CFLAGS << ' -DRB_ENC_INTERNED_STR_NULL_CHECK=1 '