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, 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                 self.eApp = getApplication()
  31
  32         def register(self, fd, eventmask = select.POLLIN | select.POLLERR | select.POLLOUT):
  33                 self.dict[fd] = eventmask
  34
  35         def unregister(self, fd):
  36                 del self.dict[fd]
  37
  38         def poll(self, timeout = None):
  39                 r = self.eApp.poll(timeout, self.dict)
  40                 return r
  41
  42 poller = E2SharedPoll()
  43
  44 class PollReactor(posixbase.PosixReactorBase):
  45         """A reactor that uses poll(2)."""
  46
  47         def _updateRegistration(self, fd):
  48                 """Register/unregister an fd with the poller."""
  49                 try:
  50                         poller.unregister(fd)
  51                 except KeyError:
  52                         pass
  53
  54                 mask = 0
  55                 if reads.has_key(fd): mask = mask | select.POLLIN
  56                 if writes.has_key(fd): mask = mask | select.POLLOUT
  57                 if mask != 0:
  58                         poller.register(fd, mask)
  59                 else:
  60                         if selectables.has_key(fd): del selectables[fd]
  61
  62
  63                 poller.eApp.interruptPoll()
  64
  65         def _dictRemove(self, selectable, mdict):
  66                 try:
  67                         # the easy way
  68                         fd = selectable.fileno()
  69                         # make sure the fd is actually real.  In some situations we can get
  70                         # -1 here.
  71                         mdict[fd]
  72                 except:
  73                         # the hard way: necessary because fileno() may disappear at any
  74                         # moment, thanks to python's underlying sockets impl
  75                         for fd, fdes in selectables.items():
  76                                 if selectable is fdes:
  77                                         break
  78                         else:
  79                                 # Hmm, maybe not the right course of action?  This method can't
  80                                 # fail, because it happens inside error detection...
  81                                 return
  82                 if mdict.has_key(fd):
  83                         del mdict[fd]
  84                         self._updateRegistration(fd)
  85
  86         def addReader(self, reader):
  87                 """Add a FileDescriptor for notification of data available to read.
  88                 """
  89                 fd = reader.fileno()
  90                 if not reads.has_key(fd):
  91                         selectables[fd] = reader
  92                         reads[fd] =  1
  93                         self._updateRegistration(fd)
  94
  95         def addWriter(self, writer, writes=writes, selectables=selectables):
  96                 """Add a FileDescriptor for notification of data available to write.
  97                 """
  98                 fd = writer.fileno()
  99                 if not writes.has_key(fd):
 100                         selectables[fd] = writer
 101                         writes[fd] =  1
 102                         self._updateRegistration(fd)
 103
 104         def removeReader(self, reader, reads=reads):
 105                 """Remove a Selectable for notification of data available to read.
 106                 """
 107                 return self._dictRemove(reader, reads)
 108
 109         def removeWriter(self, writer, writes=writes):
 110                 """Remove a Selectable for notification of data available to write.
 111                 """
 112                 return self._dictRemove(writer, writes)
 113
 114         def removeAll(self, reads=reads, writes=writes, selectables=selectables):
 115                 """Remove all selectables, and return a list of them."""
 116                 if self.waker is not None:
 117                         self.removeReader(self.waker)
 118                 result = selectables.values()
 119                 fds = selectables.keys()
 120                 reads.clear()
 121                 writes.clear()
 122                 selectables.clear()
 123                 for fd in fds:
 124                         poller.unregister(fd)
 125
 126                 if self.waker is not None:
 127                         self.addReader(self.waker)
 128                 return result
 129
 130         def doPoll(self, timeout,
 131                            reads=reads,
 132                            writes=writes,
 133                            selectables=selectables,
 134                            select=select,
 135                            log=log,
 136                            POLLIN=select.POLLIN,
 137                            POLLOUT=select.POLLOUT):
 138                 """Poll the poller for new events."""
 139
 140                 if timeout is not None:
 141                         timeout = int(timeout * 1000) # convert seconds to milliseconds
 142
 143                 try:
 144                         l = poller.poll(timeout)
 145                         if l is None:
 146                                 if self.running:
 147                                         self.stop()
 148                                 l = [ ]
 149                 except select.error, e:
 150                         if e[0] == errno.EINTR:
 151                                 return
 152                         else:
 153                                 raise
 154                 _drdw = self._doReadOrWrite
 155                 for fd, event in l:
 156                         try:
 157                                 selectable = selectables[fd]
 158                         except KeyError:
 159                                 # Handles the infrequent case where one selectable's
 160                                 # handler disconnects another.
 161                                 continue
 162                         log.callWithLogger(selectable, _drdw, selectable, fd, event, POLLIN, POLLOUT, log)
 163
 164         doIteration = doPoll
 165
 166         def _doReadOrWrite(self, selectable, fd, event, POLLIN, POLLOUT, log,
 167                 faildict={
 168                         error.ConnectionDone: failure.Failure(error.ConnectionDone()),
 169                         error.ConnectionLost: failure.Failure(error.ConnectionLost())
 170                 }):
 171                 why = None
 172                 inRead = False
 173                 if event & POLL_DISCONNECTED and not (event & POLLIN):
 174                         why = main.CONNECTION_LOST
 175                 else:
 176                         try:
 177                                 if event & POLLIN:
 178                                         why = selectable.doRead()
 179                                         inRead = True
 180                                 if not why and event & POLLOUT:
 181                                         why = selectable.doWrite()
 182                                         inRead = False
 183                                 if not selectable.fileno() == fd:
 184                                         why = error.ConnectionFdescWentAway('Filedescriptor went away')
 185                                         inRead = False
 186                         except:
 187                                 log.deferr()
 188                                 why = sys.exc_info()[1]
 189                 if why:
 190                         self._disconnectSelectable(selectable, why, inRead)
 191
 192         def callLater(self, *args, **kwargs):
 193                 poller.eApp.interruptPoll()
 194                 return posixbase.PosixReactorBase.callLater(self, *args, **kwargs)
 195
 196 def install():
 197         """Install the poll() reactor."""
 198
 199         p = PollReactor()
 200         main.installReactor(p)
 201
 202 __all__ = ["PollReactor", "install"]