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# 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 os
import sys
import logging
import threading
#pylint: disable=relative-import
import common_lib
# Map swarming_client to use subprocess42
from utils import subprocess42
class RPCMethods(object):
"""Class exposing RPC methods."""
_dotted_whitelist = ['subprocess']
def __init__(self, server):
self._server = server
self.subprocess = Subprocess
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."""'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)
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:
self.stderr += data
if self.verbose:
def KillAll(cls):
for key in cls._processes:
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):'Starting process %s', self)
self.proc = subprocess42.Popen(self.cmd, stdout=subprocess42.PIPE,
detached=self.detached, cwd=self.cwd)
def Start(cls, key):
def SetCwd(cls, key, cwd):
"""Sets the process's cwd."""
logging.debug('Setting %s cwd to %s', key, cwd)
cls._processes[key].cwd = cwd
def SetDetached(cls, key):
"""Creates a detached process."""
logging.debug('Setting %s to run detached', key)
cls._processes[key].detached = True
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
def Terminate(cls, key):
logging.debug('Terminating process %s', key)
def Kill(cls, key):
logging.debug('Killing process %s', key)
def Delete(cls, key):
if cls.GetReturncode(key) is None:
logging.warning('Killing %s before deleting it', key)
logging.debug('Deleting process %s', key)
def GetReturncode(cls, key):
return cls._processes[key].proc.returncode
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
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
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)
def Wait(cls, key):
return cls._processes[key].proc.wait()
def Poll(cls, key):
return cls._processes[key].proc.poll()
def GetPid(cls, key):
return cls._processes[key]