subprocess2, gerrit_test_case: Use SIGTERM instead of SIGKILL for Windows support

SIGKILL doesn't exist on Windows, but SIGTERM does.
For our purposes they do the same thing.

Bug: 962263
Change-Id: I16929cf7d1377cd81f71401a48b5a84fe54da493
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/1608561
Reviewed-by: Marc-Antoine Ruel <maruel@chromium.org>
Commit-Queue: Raul Tambre <raul@tambre.ee>
Auto-Submit: Raul Tambre <raul@tambre.ee>

subprocess2.py

@@ -44,10 +44,6 @@ VOID = object()
 # Error code when a process was killed because it timed out.
 TIMED_OUT = -2001
 
-# Globals.
-# Set to True if you somehow need to disable this hack.
-SUBPROCESS_CLEANUP_HACKED = False
-
 
 class CalledProcessError(subprocess.CalledProcessError):
   """Augment the standard exception with more data."""
@@ -78,51 +74,11 @@ def kill_pid(pid):
     # Unable to import 'module'
     # pylint: disable=no-member,F0401
     import signal
-    return os.kill(pid, signal.SIGKILL)
+    return os.kill(pid, signal.SIGTERM)
   except ImportError:
     pass
 
 
-def kill_win(process):
-  """Kills a process with its windows handle.
-
-  Has no effect on other platforms.
-  """
-  try:
-    # Unable to import 'module'
-    # pylint: disable=import-error
-    import win32process
-    # Access to a protected member _handle of a client class
-    # pylint: disable=protected-access
-    return win32process.TerminateProcess(process._handle, -1)
-  except ImportError:
-    pass
-
-
-def add_kill():
-  """Adds kill() method to subprocess.Popen for python <2.6"""
-  if hasattr(subprocess.Popen, 'kill'):
-    return
-
-  if sys.platform == 'win32':
-    subprocess.Popen.kill = kill_win
-  else:
-    subprocess.Popen.kill = lambda process: kill_pid(process.pid)
-
-
-def hack_subprocess():
-  """subprocess functions may throw exceptions when used in multiple threads.
-
-  See http://bugs.python.org/issue1731717 for more information.
-  """
-  global SUBPROCESS_CLEANUP_HACKED
-  if not SUBPROCESS_CLEANUP_HACKED and threading.activeCount() != 1:
-    # Only hack if there is ever multiple threads.
-    # There is no point to leak with only one thread.
-    subprocess._cleanup = lambda: None
-    SUBPROCESS_CLEANUP_HACKED = True
-
-
 def get_english_env(env):
   """Forces LANG and/or LANGUAGE to be English.
 
@@ -208,10 +164,6 @@ class Popen(subprocess.Popen):
   popen_lock = threading.Lock()
 
   def __init__(self, args, **kwargs):
-    # Make sure we hack subprocess if necessary.
-    hack_subprocess()
-    add_kill()
-
     env = get_english_env(kwargs.get('env'))
     if env:
       kwargs['env'] = env

testing_support/gerrit_test_case.py

@@ -352,9 +352,9 @@ class GerritTestCase(unittest.TestCase):
           return
 
       # If we get here, the gerrit process is still alive.  Send the process
-      # SIGKILL for good measure.
+      # SIGTERM for good measure.
       try:
-        os.kill(gerrit_instance.gerrit_pid, signal.SIGKILL)
+        os.kill(gerrit_instance.gerrit_pid, signal.SIGTERM)
       except OSError:
         if e.errno == errno.ESRCH:
           # os.kill raised an error because the process doesn't exist.  Maybe