Update from https://crrev.com/327068

testing/legion/rpc_methods.py

 # Copyright 2015 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.
 
 """Defines the task RPC methods."""
 
+import logging
 import os
 import sys
-import logging
 import threading
 
 #pylint: disable=relative-import
-import common_lib
-
-# Map swarming_client to use subprocess42
-sys.path.append(common_lib.SWARMING_DIR)
-
-from utils import subprocess42
+import process
 
 
 class RPCMethods(object):
   """Class exposing RPC methods."""
 
   _dotted_whitelist = ['subprocess']
 
   def __init__(self, server):
     self._server = server
-    self.subprocess = Subprocess
+    self.subprocess = process.Process
 
   def _dispatch(self, method, params):
     obj = self
     if '.' in method:
       # Allow only white listed dotted names
       name, method = method.split('.')
       assert name in self._dotted_whitelist
       obj = getattr(self, name)
     return getattr(obj, method)(*params)
 
   def Echo(self, message):
     """Simple RPC method to print and return a message."""
     logging.info('Echoing %s', message)
     return 'echo %s' % str(message)
 
   def AbsPath(self, path):
     """Returns the absolute path."""
     return os.path.abspath(path)
 
   def Quit(self):
     """Call _server.shutdown in another thread.
 
     This is needed because server.shutdown waits for the server to actually
     quit. However the server cannot shutdown until it completes handling this
     call. Calling this in the same thread results in a deadlock.
     """
     t = threading.Thread(target=self._server.shutdown)
     t.start()
-
-
-class Subprocess(object):
-  """Implements a server-based non-blocking subprocess.
-
-  This non-blocking subprocess allows the caller to continue operating while
-  also able to interact with this subprocess based on a key returned to
-  the caller at the time of creation.
-
-  Creation args are set via Set* methods called after calling Process but
-  before calling Start. This is due to a limitation of the XML-RPC
-  implementation not supporting keyword arguments.
-  """
-
-  _processes = {}
-  _process_next_id = 0
-  _creation_lock = threading.Lock()
-
-  def __init__(self, cmd):
-    self.stdout = ''
-    self.stderr = ''
-    self.cmd = cmd
-    self.proc = None
-    self.cwd = None
-    self.verbose = False
-    self.detached = False
-    self.data_lock = threading.Lock()
-
-  def __str__(self):
-    return '%r, cwd=%r, verbose=%r, detached=%r' % (
-        self.cmd, self.cwd, self.verbose, self.detached)
-
-  def _reader(self):
-    for pipe, data in self.proc.yield_any():
-      with self.data_lock:
-        if pipe == 'stdout':
-          self.stdout += data
-          if self.verbose:
-            sys.stdout.write(data)
-        else:
-          self.stderr += data
-          if self.verbose:
-            sys.stderr.write(data)
-
-  @classmethod
-  def KillAll(cls):
-    for key in cls._processes:
-      cls.Kill(key)
-
-  @classmethod
-  def Process(cls, cmd):
-    with cls._creation_lock:
-      key = 'Process%d' % cls._process_next_id
-      cls._process_next_id += 1
-    logging.debug('Creating process %s', key)
-    process = cls(cmd)
-    cls._processes[key] = process
-    return key
-
-  def _Start(self):
-    logging.info('Starting process %s', self)
-    self.proc = subprocess42.Popen(self.cmd, stdout=subprocess42.PIPE,
-                                   stderr=subprocess42.PIPE,
-                                   detached=self.detached, cwd=self.cwd)
-    threading.Thread(target=self._reader).start()
-
-  @classmethod
-  def Start(cls, key):
-    cls._processes[key]._Start()
-
-  @classmethod
-  def SetCwd(cls, key, cwd):
-    """Sets the process's cwd."""
-    logging.debug('Setting %s cwd to %s', key, cwd)
-    cls._processes[key].cwd = cwd
-
-  @classmethod
-  def SetDetached(cls, key):
-    """Creates a detached process."""
-    logging.debug('Setting %s to run detached', key)
-    cls._processes[key].detached = True
-
-  @classmethod
-  def SetVerbose(cls, key):
-    """Sets the stdout and stderr to be emitted locally."""
-    logging.debug('Setting %s to be verbose', key)
-    cls._processes[key].verbose = True
-
-  @classmethod
-  def Terminate(cls, key):
-    logging.debug('Terminating process %s', key)
-    cls._processes[key].proc.terminate()
-
-  @classmethod
-  def Kill(cls, key):
-    logging.debug('Killing process %s', key)
-    cls._processes[key].proc.kill()
-
-  @classmethod
-  def Delete(cls, key):
-    if cls.GetReturncode(key) is None:
-      logging.warning('Killing %s before deleting it', key)
-      cls.Kill(key)
-    logging.debug('Deleting process %s', key)
-    cls._processes.pop(key)
-
-  @classmethod
-  def GetReturncode(cls, key):
-    return cls._processes[key].proc.returncode
-
-  @classmethod
-  def ReadStdout(cls, key):
-    """Returns all stdout since the last call to ReadStdout.
-
-    This call allows the user to read stdout while the process is running.
-    However each call will flush the local stdout buffer. In order to make
-    multiple calls to ReadStdout and to retain the entire output the results
-    of this call will need to be buffered in the calling code.
-    """
-    proc = cls._processes[key]
-    with proc.data_lock:
-      # Perform a "read" on the stdout data
-      stdout = proc.stdout
-      proc.stdout = ''
-    return stdout
-
-  @classmethod
-  def ReadStderr(cls, key):
-    """Returns all stderr read since the last call to ReadStderr.
-
-    See ReadStdout for additional details.
-    """
-    proc = cls._processes[key]
-    with proc.data_lock:
-      # Perform a "read" on the stderr data
-      stderr = proc.stderr
-      proc.stderr = ''
-    return stderr
-
-  @classmethod
-  def ReadOutput(cls, key):
-    """Returns the (stdout, stderr) since the last Read* call.
-
-    See ReadStdout for additional details.
-    """
-    return cls.ReadStdout(key), cls.ReadStderr(key)
-
-  @classmethod
-  def Wait(cls, key):
-    return cls._processes[key].proc.wait()
-
-  @classmethod
-  def Poll(cls, key):
-    return cls._processes[key].proc.poll()
-
-  @classmethod
-  def GetPid(cls, key):
-    return cls._processes[key].proc.pid