Not wait cloudtail finish forerver on Windows.

scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py

Index: scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
diff --git a/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py b/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
index bfe97d81c9b55bf1b895a97ad565957f9d21e63d..aafca9b8fe055d10b66c0cd691bbb3d858006fe8 100644
--- a/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
+++ b/scripts/slave/recipe_modules/goma/resources/cloudtail_utils.py
@@ -5,6 +5,7 @@
 
 import argparse
 import errno
+import multiprocessing
 import os
 import signal
 import subprocess
@@ -54,44 +55,86 @@ class NotDiedError(Exception):
     return "NotDiedError"
 
 
-def wait_termination(pid):
-  """Send SIGINT to pid and wait termination of pid.
+def wait_termination_win(pid):
+  """Send CTRL_C_EVENT or SIGINT to pid and wait termination of pid.
 
   Args:
     pid(int): pid of process which this function waits termination.
 
-  Raises:
-    OSError: is_running_posix, os.waitpid and os.kill may throw OSError.
-    NotDiedError: if cloudtail is running after 10 seconds waiting,
-                  NotDiedError is raised.
+  Returns:
+    None: if pid has already finished or process finished succesfully.
+    instance of Exception: if raised unexpectedly.
   """
-
+  import win32api
+  import win32con
+  import pywintypes
+  handle = None
   try:
-    os.kill(pid, signal.SIGINT)
+    handle = win32api.OpenProcess(
+        win32con.PROCESS_QUERY_INFORMATION | win32con.SYNCHRONIZE,
+        False, pid)
+    try:
+      os.kill(pid, signal.CTRL_C_EVENT)
+      print('CTRL_C_EVENT has been sent to process %d. '
+            'Going to wait for the process finishes.' % pid)
+    except WindowsError as e:  # pylint: disable=E0602
+      # If a target process does not share terminal, we cannot send Ctrl-C.
+      if e.errno == 87:  # 87 == invalid parameter
+        os.kill(pid, signal.SIGINT)
+    os.waitpid(handle, 0)

[Vadim Sh., 2016/10/25 18:35:41]

I think it would be simpler to use WaitForSingleObject with timeout instead of
'multiprocessing' (now that use have process HANDLE and access to WinAPI).

[Yoshisato Yanagisawa, 2016/10/26 01:17:45]

Done.

+    return None
+  except pywintypes.error as e:
+    if e[0] == 87 and e[1] == 'OpenProcess':
+      print('Can\'t open process %d. Already dead? error %d.' % (pid, e))
+      return None
+    raise
   except OSError as e:
-    # Already dead?
     if e.errno in (errno.ECHILD, errno.EPERM, errno.ESRCH):
       print('Can\'t send SIGINT to process %d. Already dead? Errno %d.' %
             (pid, e.errno))
-      return
+      return None
     raise
+  except Exception as e:
+    return e

[Vadim Sh., 2016/10/25 18:35:41]

this is weird... is it because of 'multiprocessing'?

[Yoshisato Yanagisawa, 2016/10/26 01:17:45]

right.  revised without multiprocessing.

+  finally:
+    if handle:
+      win32api.CloseHandle(handle)
+
+
+def wait_termination(pid):
+  """Send SIGINT to pid and wait termination of pid.
 
-  print('SIGINT has been sent to process %d. '
-        'Going to wait for the process finishes.' % pid)
+  Args:
+    pid(int): pid of process which this function waits termination.
+
+  Raises:
+    OSError: is_running_posix, os.waitpid and os.kill may throw OSError.
+    NotDiedError: if cloudtail is running after 10 seconds waiting,
+                  NotDiedError is raised.
+  """
   if os.name == 'nt':
+    pool = multiprocessing.Pool(1)
+    res = pool.apply_async(wait_termination_win, [pid])
     try:
-      os.waitpid(pid, 0)
+      e = res.get(10)
+    except multiprocessing.TimeoutError:
+      print('process %d running more than 10 seconds.' % pid)
+      raise NotDiedError()
+    if e is None:
+      return
+    raise e
+  else:
+    try:
+      os.kill(pid, signal.SIGINT)
     except OSError as e:
-      if e.errno == errno.ECHILD:
-        print('process %d died before waitpitd' % pid)
+      if e.errno in (errno.ECHILD, errno.EPERM, errno.ESRCH):
+        print('Can\'t send SIGINT to process %d. Already dead? Errno %d.' %
+              (pid, e.errno))
         return
-      raise e
-  else:
     for _ in xrange(10):
       time.sleep(1)
       if not is_running_posix(pid):
         return
-
     print('process %d running more than 10 seconds' % pid)
     raise NotDiedError()
 
@@ -127,7 +170,7 @@ def main():
       pid = int(f.read())
     try:
       wait_termination(pid)
-    except (OSError, NotDiedError) as e:
+    except Exception as e:
       print('Going to send SIGTERM to process %d due to Error %s' % (pid, e))
       # Since Windows does not have SIGKILL, we need to use SIGTERM.
       try: