test/ruby/test_process.rb: use io/wait instead of timeout

Occasionally I get timeout errors during this test on an
overloaded system, so we may need to increase timeouts anyways.
For now, avoid the overhead of thread creation for every read we
do.

* test/ruby/test_process.rb (test_deadlock_by_signal_at_forking):
  use IO#wait_readable instead of timeout

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48105 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Thu Oct 23 10:22:41 2014  Eric Wong  <e@80x24.org>
+
+	* test/ruby/test_process.rb (test_deadlock_by_signal_at_forking):
+	  use IO#wait_readable instead of timeout
+
 Thu Oct 23 10:22:24 2014  Eric Wong  <e@80x24.org>
 
 	* test/ruby/test_process.rb (test_deadlock_by_signal_at_forking):

test/ruby/test_process.rb

@@ -1,6 +1,7 @@
 require 'test/unit'
 require 'tempfile'
 require 'timeout'
+require 'io/wait'
 require_relative 'envutil'
 require 'rbconfig'
 
@@ -1946,13 +1947,12 @@ EOS
     ew.close
     begin
       loop do
-        Timeout.timeout(5) do
-          runner.readpartial(100)
-        end
+        runner.wait_readable(5)
+        runner.read_nonblock(100)
       end
     rescue EOFError => e
       _, status = Process.wait2(runner.pid)
-    rescue Timeout::Error => e
+    rescue IO::WaitReadable => e
       Process.kill(:INT, runner.pid)
       raise Marshal.load(er.read.unpack("m")[0])
     end