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