/eventlet/green/subprocess.py
Python | 105 lines | 69 code | 10 blank | 26 comment | 21 complexity | 685a5d192d4bdef81ea04c52d013eeda MD5 | raw file
Possible License(s): MIT
- import errno
- import new
- import time
- import eventlet
- from eventlet import greenio
- from eventlet import patcher
- from eventlet.green import os
- from eventlet.green import select
- patcher.inject('subprocess', globals(), ('select', select))
- subprocess_orig = __import__("subprocess")
- if getattr(subprocess_orig, 'TimeoutExpired', None) is None:
- # Backported from Python 3.3.
- # https://bitbucket.org/eventlet/eventlet/issue/89
- class TimeoutExpired(Exception):
- """This exception is raised when the timeout expires while waiting for
- a child process.
- """
- def __init__(self, cmd, output=None):
- self.cmd = cmd
- self.output = output
- def __str__(self):
- return ("Command '%s' timed out after %s seconds" %
- (self.cmd, self.timeout))
- # This is the meat of this module, the green version of Popen.
- class Popen(subprocess_orig.Popen):
- """eventlet-friendly version of subprocess.Popen"""
- # We do not believe that Windows pipes support non-blocking I/O. At least,
- # the Python file objects stored on our base-class object have no
- # setblocking() method, and the Python fcntl module doesn't exist on
- # Windows. (see eventlet.greenio.set_nonblocking()) As the sole purpose of
- # this __init__() override is to wrap the pipes for eventlet-friendly
- # non-blocking I/O, don't even bother overriding it on Windows.
- if not subprocess_orig.mswindows:
- def __init__(self, args, bufsize=0, *argss, **kwds):
- self.args = args
- # Forward the call to base-class constructor
- subprocess_orig.Popen.__init__(self, args, 0, *argss, **kwds)
- # Now wrap the pipes, if any. This logic is loosely borrowed from
- # eventlet.processes.Process.run() method.
- for attr in "stdin", "stdout", "stderr":
- pipe = getattr(self, attr)
- if pipe is not None and not type(pipe) == greenio.GreenPipe:
- wrapped_pipe = greenio.GreenPipe(pipe, pipe.mode, bufsize)
- setattr(self, attr, wrapped_pipe)
- __init__.__doc__ = subprocess_orig.Popen.__init__.__doc__
- def wait(self, timeout=None, check_interval=0.01):
- # Instead of a blocking OS call, this version of wait() uses logic
- # borrowed from the eventlet 0.2 processes.Process.wait() method.
- if timeout is not None:
- endtime = time.time() + timeout
- try:
- while True:
- status = self.poll()
- if status is not None:
- return status
- if timeout is not None and time.time() > endtime:
- raise TimeoutExpired(self.args)
- eventlet.sleep(check_interval)
- except OSError, e:
- if e.errno == errno.ECHILD:
- # no child process, this happens if the child process
- # already died and has been cleaned up
- return -1
- else:
- raise
- wait.__doc__ = subprocess_orig.Popen.wait.__doc__
- if not subprocess_orig.mswindows:
- # don't want to rewrite the original _communicate() method, we
- # just want a version that uses eventlet.green.select.select()
- # instead of select.select().
- try:
- _communicate = new.function(subprocess_orig.Popen._communicate.im_func.func_code,
- globals())
- try:
- _communicate_with_select = new.function(
- subprocess_orig.Popen._communicate_with_select.im_func.func_code,
- globals())
- _communicate_with_poll = new.function(
- subprocess_orig.Popen._communicate_with_poll.im_func.func_code,
- globals())
- except AttributeError:
- pass
- except AttributeError:
- # 2.4 only has communicate
- _communicate = new.function(subprocess_orig.Popen.communicate.im_func.func_code,
- globals())
- def communicate(self, input=None):
- return self._communicate(input)
- # Borrow subprocess.call() and check_call(), but patch them so they reference
- # OUR Popen class rather than subprocess.Popen.
- call = new.function(subprocess_orig.call.func_code, globals())
- try:
- check_call = new.function(subprocess_orig.check_call.func_code, globals())
- except AttributeError:
- pass # check_call added in 2.5