telemetry: Fix killing the perf profiler

build/android/pylib/device/device_utils.py

 # Copyright 2014 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.
 
 """Provides a variety of device interactions based on adb.
 
 Eventually, this will be based on adb_wrapper.
 """
 # pylint: disable=unused-argument
 
@@ skipping 718 matching lines @@
       retries: number of retries
 
     Returns:
       The number of processes attempted to kill.
 
     Raises:
       CommandFailedError if no process was killed and |quiet| is False.
       CommandTimeoutError on timeout.
       DeviceUnreachableError on missing device.
     """
-    pids = self.GetPids(process_name)
+    pids = self.GetPids(process_name, multiple_instances=True)
+    pids = [pid for instances in pids.values() for pid in instances]
     if not pids:
       if quiet:
         return 0
       else:
         raise device_errors.CommandFailedError(
             'No process "%s"' % process_name, str(self))
 
-    cmd = ['kill', '-%d' % signum] + pids.values()
+    cmd = ['kill', '-%d' % signum] + pids
     self.RunShellCommand(cmd, as_root=as_root, check_return=True)
 
     if blocking:
       # TODO(perezu): use timeout_retry.WaitFor
       wait_period = 0.1
-      while self.GetPids(process_name):
+      while self.GetPids(process_name, multiple_instances=True):
         time.sleep(wait_period)
 
     return len(pids)
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def StartActivity(self, intent_obj, blocking=False, trace_file_name=None,
                     force_stop=False, timeout=None, retries=None):
     """Start package's activity on the device.
 
     Args:
@@ skipping 794 matching lines @@
 
     Returns:
       The device's main ABI name.
 
     Raises:
       CommandTimeoutError on timeout.
     """
     return self.GetProp('ro.product.cpu.abi')
 
   @decorators.WithTimeoutAndRetriesFromInstance()
-  def GetPids(self, process_name, timeout=None, retries=None):
+  def GetPids(self, process_name, timeout=None, retries=None,
+              multiple_instances=False):

[perezju, 2015/07/24 14:03:10]

I don't think John will like adding an extra option (maybe he will prove me
wrong?), and it leads to a somewhat messy implementation.

I propose having a GetProcessPidPairs (or something more artfully named), with
essentially the same implementation as the current GetPids, but returning a list
of (binary_name, pid) pairs.

The implementation of GetPids would then just become:

  return dict(self.GetProcessPidPairs(...))

so we don't change the expectations of existing callers, and KillAll can use the
GetProcessPidPairs to really kill all matching processes.

[Sami, 2015/07/24 14:36:40]

Yeah I wasn't super happy about the flag either. Thanks for the great idea --
I'm stealing it :)

     """Returns the PIDs of processes with the given name.
 
     Note that the |process_name| is often the package name.
 
     Args:
       process_name: A string containing the process name to get the PIDs for.
       timeout: timeout in seconds
       retries: number of retries
+      multiple_instances: Whether or not multiple instances of the same process
+          binary are supported. If True, the returned dict will have a list of
+          PIDs for each found process. If False, only a single matching PID
+          will be returned for each process.
 
     Returns:
-      A dict mapping process name to PID for each process that contained the
-      provided |process_name|.
+      A dict mapping process name to PID (or list of PIDs) for each process
+      that contained the provided |process_name|.
 
     Raises:
       CommandTimeoutError on timeout.
       DeviceUnreachableError on missing device.
     """
-    procs_pids = {}
+    procs_pids = collections.defaultdict(list) if multiple_instances else {}
     try:
       ps_output = self._RunPipedShellCommand(
           'ps | grep -F %s' % cmd_helper.SingleQuote(process_name))
     except device_errors.AdbShellCommandFailedError as e:
       if e.status and isinstance(e.status, list) and not e.status[0]:
         # If ps succeeded but grep failed, there were no processes with the
         # given name.
         return procs_pids
       else:
         raise
 
     for line in ps_output:
       try:
         ps_data = line.split()
         if process_name in ps_data[-1]:
-          procs_pids[ps_data[-1]] = ps_data[1]
+          binary_name = ps_data[-1]
+          if multiple_instances:
+            procs_pids[binary_name].append(ps_data[1])
+          else:
+            procs_pids[binary_name] = ps_data[1]
       except IndexError:
         pass
     return procs_pids
 
   @decorators.WithTimeoutAndRetriesFromInstance()
   def TakeScreenshot(self, host_path=None, timeout=None, retries=None):
     """Takes a screenshot of the device.
 
     Args:
       host_path: A string containing the path on the host to save the
@@ skipping 132 matching lines @@
   def HealthyDevices(cls):
     blacklist = device_blacklist.ReadBlacklist()
     def blacklisted(adb):
       if adb.GetDeviceSerial() in blacklist:
         logging.warning('Device %s is blacklisted.', adb.GetDeviceSerial())
         return True
       return False
 
     return [cls(adb) for adb in adb_wrapper.AdbWrapper.Devices()
             if not blacklisted(adb)]