e2reactor.py

   1 # enigma2 reactor: based on pollreactor, which is
   2 # Copyright (c) 2001-2004 Twisted Matrix Laboratories.
   3 # See LICENSE for details.
   4
   5
   6 """
   7 Maintainer: U{Felix Domke<mailto:tmbinc@elitedvb.net>}
   8 """
   9
  10 # System imports
  11 import select, errno, sys
  12
  13 # Twisted imports
  14 from twisted.python import log, threadable, failure
  15 from twisted.internet import main, posixbase, error
  16 #from twisted.internet.pollreactor import PollReactor, poller
  17
  18 from enigma import getApplication
  19
  20 # globals
  21 reads = {}
  22 writes = {}
  23 selectables = {}
  24
  25 POLL_DISCONNECTED = (select.POLLHUP | select.POLLERR | select.POLLNVAL)
  26
  27 class E2SharedPoll:
  28         def __init__(self):
  29                 self.dict = { }
  30
  31         def register(self, fd, eventmask = select.POLLIN | select.POLLERR | select.POLLOUT):
  32                 self.dict[fd] = eventmask
  33
  34         def unregister(self, fd):
  35                 del self.dict[fd]
  36
  37         def poll(self, timeout = None):
  38                 return getApplication().poll(timeout, self.dict)
  39
  40 poller = E2SharedPoll()
  41
  42 class PollReactor(posixbase.PosixReactorBase):
  43         """A reactor that uses poll(2)."""
  44
  45         def _updateRegistration(self, fd):
  46                 """Register/unregister an fd with the poller."""
  47                 try:
  48                         poller.unregister(fd)
  49                 except KeyError:
  50                         pass
  51
  52                 mask = 0
  53                 if reads.has_key(fd): mask = mask | select.POLLIN
  54                 if writes.has_key(fd): mask = mask | select.POLLOUT
  55                 if mask != 0:
  56                         poller.register(fd, mask)
  57                 else:
  58                         if selectables.has_key(fd): del selectables[fd]
  59
  60         def _dictRemove(self, selectable, mdict):
  61                 try:
  62                         # the easy way
  63                         fd = selectable.fileno()
  64                         # make sure the fd is actually real.  In some situations we can get
  65                         # -1 here.
  66                         mdict[fd]
  67                 except:
  68                         # the hard way: necessary because fileno() may disappear at any
  69                         # moment, thanks to python's underlying sockets impl
  70                         for fd, fdes in selectables.items():
  71                                 if selectable is fdes:
  72                                         break
  73                         else:
  74                                 # Hmm, maybe not the right course of action?  This method can't
  75                                 # fail, because it happens inside error detection...
  76                                 return
  77                 if mdict.has_key(fd):
  78                         del mdict[fd]
  79                         self._updateRegistration(fd)
  80
  81         def addReader(self, reader):
  82                 """Add a FileDescriptor for notification of data available to read.
  83                 """
  84                 fd = reader.fileno()
  85                 if not reads.has_key(fd):
  86                         selectables[fd] = reader
  87                         reads[fd] =  1
  88                         self._updateRegistration(fd)
  89
  90         def addWriter(self, writer, writes=writes, selectables=selectables):
  91                 """Add a FileDescriptor for notification of data available to write.
  92                 """
  93                 fd = writer.fileno()
  94                 if not writes.has_key(fd):
  95                         selectables[fd] = writer
  96                         writes[fd] =  1
  97                         self._updateRegistration(fd)
  98
  99         def removeReader(self, reader, reads=reads):
 100                 """Remove a Selectable for notification of data available to read.
 101                 """
 102                 return self._dictRemove(reader, reads)
 103
 104         def removeWriter(self, writer, writes=writes):
 105                 """Remove a Selectable for notification of data available to write.
 106                 """
 107                 return self._dictRemove(writer, writes)
 108
 109         def removeAll(self, reads=reads, writes=writes, selectables=selectables):
 110                 """Remove all selectables, and return a list of them."""
 111                 if self.waker is not None:
 112                         self.removeReader(self.waker)
 113                 result = selectables.values()
 114                 fds = selectables.keys()
 115                 reads.clear()
 116                 writes.clear()
 117                 selectables.clear()
 118                 for fd in fds:
 119                         poller.unregister(fd)
 120
 121                 if self.waker is not None:
 122                         self.addReader(self.waker)
 123                 return result
 124
 125         def doPoll(self, timeout,
 126                            reads=reads,
 127                            writes=writes,
 128                            selectables=selectables,
 129                            select=select,
 130                            log=log,
 131                            POLLIN=select.POLLIN,
 132                            POLLOUT=select.POLLOUT):
 133                 """Poll the poller for new events."""
 134                 if timeout is not None:
 135                         timeout = int(timeout * 1000) # convert seconds to milliseconds
 136
 137                 try:
 138                         l = poller.poll(timeout)
 139                         if l is None:
 140                                 if self.running:
 141                                         self.stop()
 142                                 l = [ ]
 143                 except select.error, e:
 144                         if e[0] == errno.EINTR:
 145                                 return
 146                         else:
 147                                 raise
 148                 _drdw = self._doReadOrWrite
 149                 for fd, event in l:
 150                         try:
 151                                 selectable = selectables[fd]
 152                         except KeyError:
 153                                 # Handles the infrequent case where one selectable's
 154                                 # handler disconnects another.
 155                                 continue
 156                         log.callWithLogger(selectable, _drdw, selectable, fd, event, POLLIN, POLLOUT, log)
 157
 158         doIteration = doPoll
 159
 160         def _doReadOrWrite(self, selectable, fd, event, POLLIN, POLLOUT, log,
 161                 faildict={
 162                         error.ConnectionDone: failure.Failure(error.ConnectionDone()),
 163                         error.ConnectionLost: failure.Failure(error.ConnectionLost())
 164                 }):
 165                 why = None
 166                 inRead = False
 167                 if event & POLL_DISCONNECTED and not (event & POLLIN):
 168                         why = main.CONNECTION_LOST
 169                 else:
 170                         try:
 171                                 if event & POLLIN:
 172                                         why = selectable.doRead()
 173                                         inRead = True
 174                                 if not why and event & POLLOUT:
 175                                         why = selectable.doWrite()
 176                                         inRead = False
 177                                 if not selectable.fileno() == fd:
 178                                         why = error.ConnectionFdescWentAway('Filedescriptor went away')
 179                                         inRead = False
 180                         except:
 181                                 log.deferr()
 182                                 why = sys.exc_info()[1]
 183                 if why:
 184                         self._disconnectSelectable(selectable, why, inRead)
 185
 186
 187 def install():
 188         """Install the poll() reactor."""
 189
 190         p = PollReactor()
 191         main.installReactor(p)
 192
 193 __all__ = ["PollReactor", "install"]