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| 1 # Copyright (c) 2001-2007 Twisted Matrix Laboratories. | |
| 2 # See LICENSE for details. | |
| 3 | |
| 4 | |
| 5 """ | |
| 6 A poll() based implementation of the twisted main loop. | |
| 7 | |
| 8 To install the event loop (and you should do this before any connections, | |
| 9 listeners or connectors are added):: | |
| 10 | |
| 11 from twisted.internet import pollreactor | |
| 12 pollreactor.install() | |
| 13 | |
| 14 Maintainer: U{Itamar Shtull-Trauring<mailto:twisted@itamarst.org>} | |
| 15 """ | |
| 16 | |
| 17 # System imports | |
| 18 import errno, sys | |
| 19 from select import error as SelectError, poll | |
| 20 from select import POLLIN, POLLOUT, POLLHUP, POLLERR, POLLNVAL | |
| 21 | |
| 22 from zope.interface import implements | |
| 23 | |
| 24 # Twisted imports | |
| 25 from twisted.python import log | |
| 26 from twisted.internet import main, posixbase, error | |
| 27 from twisted.internet.interfaces import IReactorFDSet | |
| 28 | |
| 29 POLL_DISCONNECTED = (POLLHUP | POLLERR | POLLNVAL) | |
| 30 | |
| 31 | |
| 32 class PollReactor(posixbase.PosixReactorBase): | |
| 33 """ | |
| 34 A reactor that uses poll(2). | |
| 35 | |
| 36 @ivar _poller: A L{poll} which will be used to check for I/O | |
| 37 readiness. | |
| 38 | |
| 39 @ivar _selectables: A dictionary mapping integer file descriptors to | |
| 40 instances of L{FileDescriptor} which have been registered with the | |
| 41 reactor. All L{FileDescriptors} which are currently receiving read or | |
| 42 write readiness notifications will be present as values in this | |
| 43 dictionary. | |
| 44 | |
| 45 @ivar _reads: A dictionary mapping integer file descriptors to arbitrary | |
| 46 values (this is essentially a set). Keys in this dictionary will be | |
| 47 registered with C{_poller} for read readiness notifications which will | |
| 48 be dispatched to the corresponding L{FileDescriptor} instances in | |
| 49 C{_selectables}. | |
| 50 | |
| 51 @ivar _writes: A dictionary mapping integer file descriptors to arbitrary | |
| 52 values (this is essentially a set). Keys in this dictionary will be | |
| 53 registered with C{_poller} for write readiness notifications which will | |
| 54 be dispatched to the corresponding L{FileDescriptor} instances in | |
| 55 C{_selectables}. | |
| 56 """ | |
| 57 implements(IReactorFDSet) | |
| 58 | |
| 59 def __init__(self): | |
| 60 """ | |
| 61 Initialize polling object, file descriptor tracking dictionaries, and | |
| 62 the base class. | |
| 63 """ | |
| 64 self._poller = poll() | |
| 65 self._selectables = {} | |
| 66 self._reads = {} | |
| 67 self._writes = {} | |
| 68 posixbase.PosixReactorBase.__init__(self) | |
| 69 | |
| 70 | |
| 71 def _updateRegistration(self, fd): | |
| 72 """Register/unregister an fd with the poller.""" | |
| 73 try: | |
| 74 self._poller.unregister(fd) | |
| 75 except KeyError: | |
| 76 pass | |
| 77 | |
| 78 mask = 0 | |
| 79 if fd in self._reads: | |
| 80 mask = mask | POLLIN | |
| 81 if fd in self._writes: | |
| 82 mask = mask | POLLOUT | |
| 83 if mask != 0: | |
| 84 self._poller.register(fd, mask) | |
| 85 else: | |
| 86 if fd in self._selectables: | |
| 87 del self._selectables[fd] | |
| 88 | |
| 89 def _dictRemove(self, selectable, mdict): | |
| 90 try: | |
| 91 # the easy way | |
| 92 fd = selectable.fileno() | |
| 93 # make sure the fd is actually real. In some situations we can get | |
| 94 # -1 here. | |
| 95 mdict[fd] | |
| 96 except: | |
| 97 # the hard way: necessary because fileno() may disappear at any | |
| 98 # moment, thanks to python's underlying sockets impl | |
| 99 for fd, fdes in self._selectables.items(): | |
| 100 if selectable is fdes: | |
| 101 break | |
| 102 else: | |
| 103 # Hmm, maybe not the right course of action? This method can't | |
| 104 # fail, because it happens inside error detection... | |
| 105 return | |
| 106 if fd in mdict: | |
| 107 del mdict[fd] | |
| 108 self._updateRegistration(fd) | |
| 109 | |
| 110 def addReader(self, reader): | |
| 111 """Add a FileDescriptor for notification of data available to read. | |
| 112 """ | |
| 113 fd = reader.fileno() | |
| 114 if fd not in self._reads: | |
| 115 self._selectables[fd] = reader | |
| 116 self._reads[fd] = 1 | |
| 117 self._updateRegistration(fd) | |
| 118 | |
| 119 def addWriter(self, writer): | |
| 120 """Add a FileDescriptor for notification of data available to write. | |
| 121 """ | |
| 122 fd = writer.fileno() | |
| 123 if fd not in self._writes: | |
| 124 self._selectables[fd] = writer | |
| 125 self._writes[fd] = 1 | |
| 126 self._updateRegistration(fd) | |
| 127 | |
| 128 def removeReader(self, reader): | |
| 129 """Remove a Selectable for notification of data available to read. | |
| 130 """ | |
| 131 return self._dictRemove(reader, self._reads) | |
| 132 | |
| 133 def removeWriter(self, writer): | |
| 134 """Remove a Selectable for notification of data available to write. | |
| 135 """ | |
| 136 return self._dictRemove(writer, self._writes) | |
| 137 | |
| 138 def removeAll(self): | |
| 139 """Remove all selectables, and return a list of them.""" | |
| 140 if self.waker is not None: | |
| 141 self.removeReader(self.waker) | |
| 142 result = self._selectables.values() | |
| 143 fds = self._selectables.keys() | |
| 144 self._reads.clear() | |
| 145 self._writes.clear() | |
| 146 self._selectables.clear() | |
| 147 for fd in fds: | |
| 148 self._poller.unregister(fd) | |
| 149 | |
| 150 if self.waker is not None: | |
| 151 self.addReader(self.waker) | |
| 152 return result | |
| 153 | |
| 154 def doPoll(self, timeout): | |
| 155 """Poll the poller for new events.""" | |
| 156 if timeout is not None: | |
| 157 timeout = int(timeout * 1000) # convert seconds to milliseconds | |
| 158 | |
| 159 try: | |
| 160 l = self._poller.poll(timeout) | |
| 161 except SelectError, e: | |
| 162 if e[0] == errno.EINTR: | |
| 163 return | |
| 164 else: | |
| 165 raise | |
| 166 _drdw = self._doReadOrWrite | |
| 167 for fd, event in l: | |
| 168 try: | |
| 169 selectable = self._selectables[fd] | |
| 170 except KeyError: | |
| 171 # Handles the infrequent case where one selectable's | |
| 172 # handler disconnects another. | |
| 173 continue | |
| 174 log.callWithLogger(selectable, _drdw, selectable, fd, event) | |
| 175 | |
| 176 doIteration = doPoll | |
| 177 | |
| 178 def _doReadOrWrite(self, selectable, fd, event): | |
| 179 why = None | |
| 180 inRead = False | |
| 181 if event & POLL_DISCONNECTED and not (event & POLLIN): | |
| 182 why = main.CONNECTION_LOST | |
| 183 else: | |
| 184 try: | |
| 185 if event & POLLIN: | |
| 186 why = selectable.doRead() | |
| 187 inRead = True | |
| 188 if not why and event & POLLOUT: | |
| 189 why = selectable.doWrite() | |
| 190 inRead = False | |
| 191 if not selectable.fileno() == fd: | |
| 192 why = error.ConnectionFdescWentAway('Filedescriptor went awa
y') | |
| 193 inRead = False | |
| 194 except: | |
| 195 log.deferr() | |
| 196 why = sys.exc_info()[1] | |
| 197 if why: | |
| 198 self._disconnectSelectable(selectable, why, inRead) | |
| 199 | |
| 200 | |
| 201 def getReaders(self): | |
| 202 return [self._selectables[fd] for fd in self._reads] | |
| 203 | |
| 204 | |
| 205 def getWriters(self): | |
| 206 return [self._selectables[fd] for fd in self._writes] | |
| 207 | |
| 208 | |
| 209 | |
| 210 def install(): | |
| 211 """Install the poll() reactor.""" | |
| 212 p = PollReactor() | |
| 213 from twisted.internet.main import installReactor | |
| 214 installReactor(p) | |
| 215 | |
| 216 | |
| 217 __all__ = ["PollReactor", "install"] | |
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Chromium Code Reviews
Issue 12261012:
Remove third_party/twisted_8_1 (Closed)
Base URL: svn://svn.chromium.org/chrome/trunk/tools/build