From f6e2c41db30cc3d46053de70dbfe87a5db24d58d Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Mon, 11 Jan 2021 11:14:28 +0900
Subject: [PATCH] [ruby/etc] Check blocking variables at release

https://github.com/ruby/etc/commit/f017bdfedf
---
 ext/etc/etc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/ext/etc/etc.c b/ext/etc/etc.c
index 477423c9ed..44273ff9ad 100644
--- a/ext/etc/etc.c
+++ b/ext/etc/etc.c
@@ -253,7 +253,9 @@ static VALUE
 passwd_ensure(VALUE _)
 {
     endpwent();
-    passwd_blocking = 0;
+    if (RUBY_ATOMIC_EXCHANGE(passwd_blocking, 0) != 1) {
+	rb_raise(rb_eRuntimeError, "unexpected passwd_blocking");
+    }
     return Qnil;
 }
 
@@ -495,7 +497,9 @@ static VALUE
 group_ensure(VALUE _)
 {
     endgrent();
-    group_blocking = 0;
+    if (RUBY_ATOMIC_EXCHANGE(group_blocking, 0) != 1) {
+	rb_raise(rb_eRuntimeError, "unexpected group_blocking");
+    }
     return Qnil;
 }