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| 1 # Copyright (c) 2001-2007 Twisted Matrix Laboratories. | |
| 2 # See LICENSE for details. | |
| 3 | |
| 4 """ | |
| 5 An epoll() based implementation of the twisted main loop. | |
| 6 | |
| 7 To install the event loop (and you should do this before any connections, | |
| 8 listeners or connectors are added):: | |
| 9 | |
| 10 from twisted.internet import epollreactor | |
| 11 epollreactor.install() | |
| 12 | |
| 13 Maintainer: U{Jp Calderone <mailto:exarkun@twistedmatrix.com>} | |
| 14 """ | |
| 15 | |
| 16 import sys, errno | |
| 17 | |
| 18 from zope.interface import implements | |
| 19 | |
| 20 from twisted.internet.interfaces import IReactorFDSet | |
| 21 | |
| 22 from twisted.python import _epoll | |
| 23 from twisted.python import log | |
| 24 from twisted.internet import posixbase, error | |
| 25 from twisted.internet.main import CONNECTION_LOST | |
| 26 | |
| 27 | |
| 28 _POLL_DISCONNECTED = (_epoll.HUP | _epoll.ERR) | |
| 29 | |
| 30 class EPollReactor(posixbase.PosixReactorBase): | |
| 31 """ | |
| 32 A reactor that uses epoll(4). | |
| 33 | |
| 34 @ivar _poller: A L{poll} which will be used to check for I/O | |
| 35 readiness. | |
| 36 | |
| 37 @ivar _selectables: A dictionary mapping integer file descriptors to | |
| 38 instances of L{FileDescriptor} which have been registered with the | |
| 39 reactor. All L{FileDescriptors} which are currently receiving read or | |
| 40 write readiness notifications will be present as values in this | |
| 41 dictionary. | |
| 42 | |
| 43 @ivar _reads: A dictionary mapping integer file descriptors to arbitrary | |
| 44 values (this is essentially a set). Keys in this dictionary will be | |
| 45 registered with C{_poller} for read readiness notifications which will | |
| 46 be dispatched to the corresponding L{FileDescriptor} instances in | |
| 47 C{_selectables}. | |
| 48 | |
| 49 @ivar _writes: A dictionary mapping integer file descriptors to arbitrary | |
| 50 values (this is essentially a set). Keys in this dictionary will be | |
| 51 registered with C{_poller} for write readiness notifications which will | |
| 52 be dispatched to the corresponding L{FileDescriptor} instances in | |
| 53 C{_selectables}. | |
| 54 """ | |
| 55 implements(IReactorFDSet) | |
| 56 | |
| 57 def __init__(self): | |
| 58 """ | |
| 59 Initialize epoll object, file descriptor tracking dictionaries, and the | |
| 60 base class. | |
| 61 """ | |
| 62 # Create the poller we're going to use. The 1024 here is just a hint | |
| 63 # to the kernel, it is not a hard maximum. | |
| 64 self._poller = _epoll.epoll(1024) | |
| 65 self._reads = {} | |
| 66 self._writes = {} | |
| 67 self._selectables = {} | |
| 68 posixbase.PosixReactorBase.__init__(self) | |
| 69 | |
| 70 | |
| 71 def _add(self, xer, primary, other, selectables, event, antievent): | |
| 72 """ | |
| 73 Private method for adding a descriptor from the event loop. | |
| 74 | |
| 75 It takes care of adding it if new or modifying it if already added | |
| 76 for another state (read -> read/write for example). | |
| 77 """ | |
| 78 fd = xer.fileno() | |
| 79 if fd not in primary: | |
| 80 cmd = _epoll.CTL_ADD | |
| 81 flags = event | |
| 82 if fd in other: | |
| 83 flags |= antievent | |
| 84 cmd = _epoll.CTL_MOD | |
| 85 primary[fd] = 1 | |
| 86 selectables[fd] = xer | |
| 87 # epoll_ctl can raise all kinds of IOErrors, and every one | |
| 88 # indicates a bug either in the reactor or application-code. | |
| 89 # Let them all through so someone sees a traceback and fixes | |
| 90 # something. We'll do the same thing for every other call to | |
| 91 # this method in this file. | |
| 92 self._poller._control(cmd, fd, flags) | |
| 93 | |
| 94 | |
| 95 def addReader(self, reader): | |
| 96 """ | |
| 97 Add a FileDescriptor for notification of data available to read. | |
| 98 """ | |
| 99 self._add(reader, self._reads, self._writes, self._selectables, _epoll.I
N, _epoll.OUT) | |
| 100 | |
| 101 | |
| 102 def addWriter(self, writer): | |
| 103 """ | |
| 104 Add a FileDescriptor for notification of data available to write. | |
| 105 """ | |
| 106 self._add(writer, self._writes, self._reads, self._selectables, _epoll.O
UT, _epoll.IN) | |
| 107 | |
| 108 | |
| 109 def _remove(self, xer, primary, other, selectables, event, antievent): | |
| 110 """ | |
| 111 Private method for removing a descriptor from the event loop. | |
| 112 | |
| 113 It does the inverse job of _add, and also add a check in case of the fd | |
| 114 has gone away. | |
| 115 """ | |
| 116 fd = xer.fileno() | |
| 117 if fd == -1: | |
| 118 for fd, fdes in selectables.items(): | |
| 119 if xer is fdes: | |
| 120 break | |
| 121 else: | |
| 122 return | |
| 123 if fd in primary: | |
| 124 cmd = _epoll.CTL_DEL | |
| 125 flags = event | |
| 126 if fd in other: | |
| 127 flags = antievent | |
| 128 cmd = _epoll.CTL_MOD | |
| 129 else: | |
| 130 del selectables[fd] | |
| 131 del primary[fd] | |
| 132 # See comment above _control call in _add. | |
| 133 self._poller._control(cmd, fd, flags) | |
| 134 | |
| 135 | |
| 136 def removeReader(self, reader): | |
| 137 """ | |
| 138 Remove a Selectable for notification of data available to read. | |
| 139 """ | |
| 140 self._remove(reader, self._reads, self._writes, self._selectables, _epol
l.IN, _epoll.OUT) | |
| 141 | |
| 142 | |
| 143 def removeWriter(self, writer): | |
| 144 """ | |
| 145 Remove a Selectable for notification of data available to write. | |
| 146 """ | |
| 147 self._remove(writer, self._writes, self._reads, self._selectables, _epol
l.OUT, _epoll.IN) | |
| 148 | |
| 149 def removeAll(self): | |
| 150 """ | |
| 151 Remove all selectables, and return a list of them. | |
| 152 """ | |
| 153 if self.waker is not None: | |
| 154 fd = self.waker.fileno() | |
| 155 if fd in self._reads: | |
| 156 del self._reads[fd] | |
| 157 del self._selectables[fd] | |
| 158 result = self._selectables.values() | |
| 159 fds = self._selectables.keys() | |
| 160 self._reads.clear() | |
| 161 self._writes.clear() | |
| 162 self._selectables.clear() | |
| 163 for fd in fds: | |
| 164 try: | |
| 165 # Actually, we'll ignore all errors from this, since it's | |
| 166 # just last-chance cleanup. | |
| 167 self._poller._control(_epoll.CTL_DEL, fd, 0) | |
| 168 except IOError: | |
| 169 pass | |
| 170 if self.waker is not None: | |
| 171 fd = self.waker.fileno() | |
| 172 self._reads[fd] = 1 | |
| 173 self._selectables[fd] = self.waker | |
| 174 return result | |
| 175 | |
| 176 | |
| 177 def getReaders(self): | |
| 178 return [self._selectables[fd] for fd in self._reads] | |
| 179 | |
| 180 | |
| 181 def getWriters(self): | |
| 182 return [self._selectables[fd] for fd in self._writes] | |
| 183 | |
| 184 | |
| 185 def doPoll(self, timeout): | |
| 186 """ | |
| 187 Poll the poller for new events. | |
| 188 """ | |
| 189 if timeout is None: | |
| 190 timeout = 1 | |
| 191 timeout = int(timeout * 1000) # convert seconds to milliseconds | |
| 192 | |
| 193 try: | |
| 194 # Limit the number of events to the number of io objects we're | |
| 195 # currently tracking (because that's maybe a good heuristic) and | |
| 196 # the amount of time we block to the value specified by our | |
| 197 # caller. | |
| 198 l = self._poller.wait(len(self._selectables), timeout) | |
| 199 except IOError, err: | |
| 200 if err.errno == errno.EINTR: | |
| 201 return | |
| 202 # See epoll_wait(2) for documentation on the other conditions | |
| 203 # under which this can fail. They can only be due to a serious | |
| 204 # programming error on our part, so let's just announce them | |
| 205 # loudly. | |
| 206 raise | |
| 207 | |
| 208 _drdw = self._doReadOrWrite | |
| 209 for fd, event in l: | |
| 210 try: | |
| 211 selectable = self._selectables[fd] | |
| 212 except KeyError: | |
| 213 pass | |
| 214 else: | |
| 215 log.callWithLogger(selectable, _drdw, selectable, fd, event) | |
| 216 | |
| 217 doIteration = doPoll | |
| 218 | |
| 219 def _doReadOrWrite(self, selectable, fd, event): | |
| 220 """ | |
| 221 fd is available for read or write, make the work and raise errors | |
| 222 if necessary. | |
| 223 """ | |
| 224 why = None | |
| 225 inRead = False | |
| 226 if event & _POLL_DISCONNECTED and not (event & _epoll.IN): | |
| 227 why = CONNECTION_LOST | |
| 228 else: | |
| 229 try: | |
| 230 if event & _epoll.IN: | |
| 231 why = selectable.doRead() | |
| 232 inRead = True | |
| 233 if not why and event & _epoll.OUT: | |
| 234 why = selectable.doWrite() | |
| 235 inRead = False | |
| 236 if selectable.fileno() != fd: | |
| 237 why = error.ConnectionFdescWentAway( | |
| 238 'Filedescriptor went away') | |
| 239 inRead = False | |
| 240 except: | |
| 241 log.err() | |
| 242 why = sys.exc_info()[1] | |
| 243 if why: | |
| 244 self._disconnectSelectable(selectable, why, inRead) | |
| 245 | |
| 246 def install(): | |
| 247 """ | |
| 248 Install the epoll() reactor. | |
| 249 """ | |
| 250 p = EPollReactor() | |
| 251 from twisted.internet.main import installReactor | |
| 252 installReactor(p) | |
| 253 | |
| 254 | |
| 255 __all__ = ["EPollReactor", "install"] | |
| 256 | |
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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