1 files changed, 0 insertions, 184 deletions
diff --git a/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/_signals.py b/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/_signals.py
deleted file mode 100755
index 4cc82b89..00000000
--- a/lib/python2.7/site-packages/Twisted-12.2.0-py2.7-linux-x86_64.egg/twisted/internet/_signals.py
+++ /dev/null
@@ -1,184 +0,0 @@
-# -*- test-case-name: twisted.test.test_process,twisted.internet.test.test_process -*-
-# Copyright (c) Twisted Matrix Laboratories.
-# See LICENSE for details.
-
-"""
-This module provides a uniform interface to the several mechanisms which are
-possibly available for dealing with signals.
-
-This module is used to integrate child process termination into a
-reactor event loop.  This is a challenging feature to provide because
-most platforms indicate process termination via SIGCHLD and do not
-provide a way to wait for that signal and arbitrary I/O events at the
-same time.  The naive implementation involves installing a Python
-SIGCHLD handler; unfortunately this leads to other syscalls being
-interrupted (whenever SIGCHLD is received) and failing with EINTR
-(which almost no one is prepared to handle).  This interruption can be
-disabled via siginterrupt(2) (or one of the equivalent mechanisms);
-however, if the SIGCHLD is delivered by the platform to a non-main
-thread (not a common occurrence, but difficult to prove impossible),
-the main thread (waiting on select() or another event notification
-API) may not wake up leading to an arbitrary delay before the child
-termination is noticed.
-
-The basic solution to all these issues involves enabling SA_RESTART
-(ie, disabling system call interruption) and registering a C signal
-handler which writes a byte to a pipe.  The other end of the pipe is
-registered with the event loop, allowing it to wake up shortly after
-SIGCHLD is received.  See L{twisted.internet.posixbase._SIGCHLDWaker}
-for the implementation of the event loop side of this solution.  The
-use of a pipe this way is known as the U{self-pipe
-trick<http://cr.yp.to/docs/selfpipe.html>}.
-
-The actual solution implemented in this module depends on the version
-of Python.  From version 2.6, C{signal.siginterrupt} and
-C{signal.set_wakeup_fd} allow the necessary C signal handler which
-writes to the pipe to be registered with C{SA_RESTART}.  Prior to 2.6,
-the L{twisted.internet._sigchld} extension module provides similar
-functionality.
-
-If neither of these is available, a Python signal handler is used
-instead.  This is essentially the naive solution mentioned above and
-has the problems described there.
-"""
-
-import os
-
-try:
-    from signal import set_wakeup_fd, siginterrupt
-except ImportError:
-    set_wakeup_fd = siginterrupt = None
-
-try:
-    import signal
-except ImportError:
-    signal = None
-
-from twisted.python.log import msg
-
-try:
-    from twisted.internet._sigchld import installHandler as _extInstallHandler, \
-        isDefaultHandler as _extIsDefaultHandler
-except ImportError:
-    _extInstallHandler = _extIsDefaultHandler = None
-
-
-class _Handler(object):
-    """
-    L{_Handler} is a signal handler which writes a byte to a file descriptor
-    whenever it is invoked.
-
-    @ivar fd: The file descriptor to which to write.  If this is C{None},
-        nothing will be written.
-    """
-    def __init__(self, fd):
-        self.fd = fd
-
-
-    def __call__(self, *args):
-        """
-        L{_Handler.__call__} is the signal handler.  It will write a byte to
-        the wrapped file descriptor, if there is one.
-        """
-        if self.fd is not None:
-            try:
-                os.write(self.fd, '\0')
-            except:
-                pass
-
-
-
-def _installHandlerUsingSignal(fd):
-    """
-    Install a signal handler which will write a byte to C{fd} when
-    I{SIGCHLD} is received.
-
-    This is implemented by creating an instance of L{_Handler} with C{fd}
-    and installing it as the signal handler.
-
-    @param fd: The file descriptor to which to write when I{SIGCHLD} is
-        received.
-    @type fd: C{int}
-    """
-    if fd == -1:
-        previous = signal.signal(signal.SIGCHLD, signal.SIG_DFL)
-    else:
-        previous = signal.signal(signal.SIGCHLD, _Handler(fd))
-    if isinstance(previous, _Handler):
-        return previous.fd
-    return -1
-
-
-
-def _installHandlerUsingSetWakeup(fd):
-    """
-    Install a signal handler which will write a byte to C{fd} when
-    I{SIGCHLD} is received.
-
-    This is implemented by installing an instance of L{_Handler} wrapped
-    around C{None}, setting the I{SIGCHLD} handler as not allowed to
-    interrupt system calls, and using L{signal.set_wakeup_fd} to do the
-    actual writing.
-
-    @param fd: The file descriptor to which to write when I{SIGCHLD} is
-        received.
-    @type fd: C{int}
-    """
-    if fd == -1:
-        signal.signal(signal.SIGCHLD, signal.SIG_DFL)
-    else:
-        signal.signal(signal.SIGCHLD, _Handler(None))
-        siginterrupt(signal.SIGCHLD, False)
-    return set_wakeup_fd(fd)
-
-
-
-def _isDefaultHandler():
-    """
-    Determine whether the I{SIGCHLD} handler is the default or not.
-    """
-    return signal.getsignal(signal.SIGCHLD) == signal.SIG_DFL
-
-
-
-def _cannotInstallHandler(fd):
-    """
-    Fail to install a signal handler for I{SIGCHLD}.
-
-    This implementation is used when the supporting code for the other
-    implementations is unavailable (on Python versions 2.5 and older where
-    neither the L{twisted.internet._sigchld} extension nor the standard
-    L{signal} module is available).
-
-    @param fd: Ignored; only for compatibility with the other
-        implementations of this interface.
-
-    @raise RuntimeError: Always raised to indicate no I{SIGCHLD} handler can
-        be installed.
-    """
-    raise RuntimeError("Cannot install a SIGCHLD handler")
-
-
-
-def _cannotDetermineDefault():
-    raise RuntimeError("No usable signal API available")
-
-
-
-if set_wakeup_fd is not None:
-    msg('using set_wakeup_fd')
-    installHandler = _installHandlerUsingSetWakeup
-    isDefaultHandler = _isDefaultHandler
-elif _extInstallHandler is not None:
-    msg('using _sigchld')
-    installHandler = _extInstallHandler
-    isDefaultHandler = _extIsDefaultHandler
-elif signal is not None:
-    msg('using signal module')
-    installHandler = _installHandlerUsingSignal
-    isDefaultHandler = _isDefaultHandler
-else:
-    msg('nothing unavailable')
-    installHandler = _cannotInstallHandler
-    isDefaultHandler = _cannotDetermineDefault
-