thread.c: avoid busy looping on rb_thread_fd_close

We no longer use it this function, but extensions do, and
we need to ensure it continues to work for them.

* thread.c (rb_thread_fd_close): schedule other threads in loop
* ext/-test-/thread_fd_close/thread_fd_close.c: new file
* ext/-test-/thread_fd_close/depend: ditto
* ext/-test-/thread_fd_close/extconf.rb: ditto
* test/-ext-/thread_fd_close/test_thread_fd_close.rb: new test

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59030 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 23 insertions, 0 deletions

diff --git a/test/-ext-/thread_fd_close/test_thread_fd_close.rb b/test/-ext-/thread_fd_close/test_thread_fd_close.rb
new file mode 100644
index 0000000000..c83b06d672
--- /dev/null
+++ b/test/-ext-/thread_fd_close/test_thread_fd_close.rb
@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+require 'test/unit'
+require '-test-/thread_fd_close'
+require 'io/wait'
+
+class TestThreadFdClose < Test::Unit::TestCase
+
+  def test_thread_fd_close
+    IO.pipe do |r, w|
+      th = Thread.new do
+        begin
+          r.read(4)
+        ensure
+          w.syswrite('done')
+        end
+      end
+      Thread.pass until th.stop?
+      IO.thread_fd_close(r.fileno)
+      assert_equal 'done', r.read(4)
+      assert_raise(IOError) { th.join }
+    end
+  end
+end