popen.py 文件源码

def Popen(*args, **kwargs):
    """
    Wrapper for subprocess.Popen() that provides thread-safety and works around
    other known bugs.
    """
    _popen_lock.acquire()
    try:
        # Python's subprocess module has a bug where it propagates the
        # exception to the caller when it gets interrupted trying to read the
        # status back from the child process, leaving the child process
        # effectively orphaned and registering a false failure. To work around
        # it, we temporarily replace os.read with a retrying version that
        # allows Popen to succeed in this case.
        class RetryFunc(object):
            def __init__ (self, func):
                import os
                self.func = func

            def __call__ (self, *args, **kwargs):
                while True:
                    try:
                        return self.func(*args, **kwargs)
                    except OSError, e:
                        if e.errno != errno.EINTR:
                            raise

        reader = RetryFunc(os.read)
        os.read = reader
        return subprocess.Popen(*args, **kwargs)
    finally:
        os.read = reader.func
        _popen_lock.release()