Revision 112d240d lib/daemon.py
| b/lib/daemon.py | ||
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"""Module with helper classes and functions for daemons""" |
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import asyncore |
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import os |
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import select |
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import signal |
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"""Constructs a new Mainloop instance. |
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""" |
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self._io_wait = {}
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self._signal_wait = [] |
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self._poller = select.poll() |
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@utils.SignalHandled([signal.SIGCHLD]) |
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@utils.SignalHandled([signal.SIGTERM]) |
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if stop_on_empty and not (self._io_wait): |
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break |
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# Wait for I/O events |
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try: |
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io_events = self._poller.poll(None) |
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except select.error, err: |
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# EINTR can happen when signals are sent |
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if err.args and err.args[0] in (errno.EINTR,): |
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io_events = None |
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else: |
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raise |
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if io_events: |
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# Check for I/O events |
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for (evfd, evcond) in io_events: |
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owner = self._io_wait.get(evfd, None) |
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if owner: |
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owner.OnIO(evfd, evcond) |
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asyncore.loop(timeout=5, count=1, use_poll=True) |
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# Check whether a signal was raised |
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for sig in signal_handlers: |
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for owner in self._signal_wait: |
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owner.OnSignal(signal.SIGCHLD) |
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def RegisterIO(self, owner, fd, condition): |
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"""Registers a receiver for I/O notifications |
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The receiver must support a "OnIO(self, fd, conditions)" function. |
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@type owner: instance |
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@param owner: Receiver |
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@type fd: int |
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@param fd: File descriptor |
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@type condition: int |
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@param condition: ORed field of conditions to be notified |
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(see select module) |
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""" |
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# select.Poller also supports file() like objects, but we don't. |
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assert isinstance(fd, (int, long)), \ |
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"Only integers are supported for file descriptors" |
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self._io_wait[fd] = owner |
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self._poller.register(fd, condition) |
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def RegisterSignal(self, owner): |
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"""Registers a receiver for signal notifications |
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