Fixes and add smoke test: hard timeout on isolated task.

appengine/components/tool_support/local_app.py

 #!/usr/bin/env python
 # Copyright 2014 The Swarming Authors. All rights reserved.
 # Use of this source code is governed by the Apache v2.0 license that can be
 # found in the LICENSE file.
 
 """Tools to control application running via dev_appserver.py.
 
 Useful for smoke and integration tests.
 """
 
@@ skipping 163 matching lines @@
           break
       time.sleep(0.05)
     if not alive:
       logging.error('Service %s did\'t come online', self.app_id)
       self.stop()
       self.dump_log()
       raise Exception('Failed to start %s' % self.app_id)
     logging.info('Service %s is ready.', self.app_id)
     self._serving = True
 
-  def stop(self):
+  def stop(self, leak=False):
     """Stops dev_appserver, collects its log.
 
     Returns the process error code if applicable.
     """
     if not self._proc:
       return None
     exit_code = self._proc.poll()
     try:
       logging.info('Stopping %s', self.app_id)
       if self._proc.poll() is None:
         try:
           # Send SIGTERM.
           self._proc.terminate()
         except OSError:
           pass
         deadline = time.time() + 5
         while self._proc.poll() is None and time.time() < deadline:
           time.sleep(0.05)
         exit_code = self._proc.poll()
         if exit_code is None:
           logging.error('Leaking PID %d', self._proc.pid)
     finally:
       with open(os.path.join(self._temp_root, 'dev_appserver.log'), 'r') as f:
         self._log = f.read()
-      try:
-        shutil.rmtree(self._temp_root)
-      except OSError as e:
-        # Log but ignore it to not mask other errors.
-        print >> sys.stderr, str(e)
+      if not leak:
+        try:
+          shutil.rmtree(self._temp_root)
+        except OSError as e:
+          # Log but ignore it to not mask other errors.
+          print >> sys.stderr, str(e)
       self._client = None
       self._port = None
       self._proc = None
       self._serving = False
       self._temp_root = None
     return exit_code
 
   def wait(self):
     """Waits for the process to exit."""
     self._proc.wait()
@@ skipping 68 matching lines @@
 
     It only works with apps that use 'auth' component.
     """
     if self._xsrf_token is None:
       resp = self.json_request(
           '/auth/api/v1/accounts/self/xsrf_token',
           body={},
           headers={'X-XSRF-Token-Request': '1'})
       self._xsrf_token = resp.body['xsrf_token'].encode('ascii')
     return self._xsrf_token