* io.c (fill_cbuf): finish reading at EOF, and the readconv has

  been cleared by another thread while io_fillbuf() is waiting at
  select().  a patch in [ruby-core:37197] by Hiroshi Shirosaki
  <h.shirosaki AT gmail.com>.  fixed #3840

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32169 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 20 insertions, 0 deletions

diff --git a/test/ruby/test_io.rb b/test/ruby/test_io.rb
index 3df7771d6c..0325867496 100644
--- a/test/ruby/test_io.rb
+++ b/test/ruby/test_io.rb
@@ -1955,4 +1955,24 @@ End
       assert_nothing_raised(TypeError) { File.binwrite(path, "string", mode: "w", encoding: "EUC-JP") }
     end
   end
+
+  def test_race_between_read
+    file = Tempfile.new("test")
+    path = file.path
+    file.close
+    write_file = File.open(path, "wt")
+    read_file = File.open(path, "rt")
+
+    threads = []
+    10.times do |i|
+      threads << Thread.new {write_file.print(i)}
+      threads << Thread.new {read_file.read}
+    end
+    threads.each {|t| t.join}
+    assert(true, "[ruby-core:37197]")
+  ensure
+    read_file.close
+    write_file.close
+    file.close!
+  end
 end