Implement accelerated tee support for POSIX.

tests/subprocess2_test.py

 #!/usr/bin/env python
 # Copyright (c) 2011 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Unit tests for subprocess2.py."""
 
 import logging
 import optparse
 import os
 import sys
 import time
 import unittest
 
+try:
+  import fcntl
+except ImportError:
+  fcntl = None
+
 ROOT_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
 sys.path.insert(0, ROOT_DIR)
 
 import subprocess2
 
 # Method could be a function
 # pylint: disable=R0201
 
 
 def convert_to_crlf(string):
@@ skipping 150 matching lines @@
       self.fail()
     except TypeError:
       pass
 
 
 class S2Test(unittest.TestCase):
   def setUp(self):
     super(S2Test, self).setUp()
     self.exe_path = __file__
     self.exe = [sys.executable, self.exe_path, '--child']
+    self.states = {}
+    if fcntl:
+      for v in (sys.stdin, sys.stdout, sys.stderr):
+        fileno = v.fileno()
+        self.states[fileno] = fcntl.fcntl(fileno, fcntl.F_GETFL)
+
+  def tearDown(self):
+    for fileno, fl in self.states.iteritems():
+      self.assertEquals(fl, fcntl.fcntl(fileno, fcntl.F_GETFL))
+    super(S2Test, self).tearDown()
 
   def _run_test(self, function):
     """Runs tests in 6 combinations:
     - LF output with universal_newlines=False
     - CR output with universal_newlines=False
     - CRLF output with universal_newlines=False
     - LF output with universal_newlines=True
     - CR output with universal_newlines=True
     - CRLF output with universal_newlines=True
 
@@ skipping 240 matching lines @@
   return options.return_value
 
 
 if __name__ == '__main__':
   logging.basicConfig(level=
       [logging.WARNING, logging.INFO, logging.DEBUG][
         min(2, sys.argv.count('-v'))])
   if len(sys.argv) > 1 and sys.argv[1] == '--child':
     sys.exit(child_main(sys.argv[2:]))
   unittest.main()