EventLoop: use epoll when available

This will fix bug #432024.

diff --git a/pym/portage/util/_eventloop/EventLoop.py b/pym/portage/util/_eventloop/EventLoop.py
index bbbce52..eed68fe 100644 (file)
--- a/pym/portage/util/_eventloop/EventLoop.py
+++ b/pym/portage/util/_eventloop/EventLoop.py
@@ -52,14 +52,25 @@ class EventLoop(object):
                self._idle_callbacks = {}
                self._timeout_handlers = {}
                self._timeout_interval = None
-               self._poll_obj = create_poll_instance()
 
-               self.IO_ERR = PollConstants.POLLERR
-               self.IO_HUP = PollConstants.POLLHUP
-               self.IO_IN = PollConstants.POLLIN
-               self.IO_NVAL = PollConstants.POLLNVAL
-               self.IO_OUT = PollConstants.POLLOUT
-               self.IO_PRI = PollConstants.POLLPRI
+               try:
+                       select.epoll
+               except AttributeError:
+                       self._poll_obj = create_poll_instance()
+                       self.IO_ERR = PollConstants.POLLERR
+                       self.IO_HUP = PollConstants.POLLHUP
+                       self.IO_IN = PollConstants.POLLIN
+                       self.IO_NVAL = PollConstants.POLLNVAL
+                       self.IO_OUT = PollConstants.POLLOUT
+                       self.IO_PRI = PollConstants.POLLPRI
+               else:
+                       self._poll_obj = _epoll_adapter(select.epoll())
+                       self.IO_ERR = select.EPOLLERR
+                       self.IO_HUP = select.EPOLLHUP
+                       self.IO_IN = select.EPOLLIN
+                       self.IO_NVAL = 0
+                       self.IO_OUT = select.EPOLLOUT
+                       self.IO_PRI = select.EPOLLPRI
 
                self._child_handlers = {}
                self._sigchld_read = None
@@ -488,3 +499,37 @@ def create_poll_instance():
        if can_poll_device():
                return select.poll()
        return PollSelectAdapter()
+
+class _epoll_adapter(object):
+       """
+       Wraps a select.epoll instance in order to make it compatible
+       with select.poll instances. This is necessary since epoll instances
+       interpret timeout arguments differently. Note that the file descriptor
+       that is associated with an epoll instance will close automatically when
+       it is garbage collected, so it's not necessary to close it explicitly.
+       """
+       __slots__ = ('_epoll_obj',)
+
+       def __init__(self, epoll_obj):
+               self._epoll_obj = epoll_obj
+
+       def register(self, fd, *args):
+               self._epoll_obj.register(fd, *args)
+
+       def unregister(self, fd):
+               self._epoll_obj.unregister(fd)
+
+       def poll(self, *args):
+               if len(args) > 1:
+                       raise TypeError(
+                               "poll expected at most 2 arguments, got " + \
+                               repr(1 + len(args)))
+               timeout = -1
+               if args:
+                       timeout = args[0]
+                       if timeout is None or timeout < 0:
+                               timeout = -1
+                       elif timeout != 0:
+                                timeout = timeout / 1000
+
+               return self._epoll_obj.poll(timeout)