def _unwatchFD(self, fd, descr, flag):
"""
Unregister a file descriptor with the C{CFRunLoop}, or modify its state
so that it's listening for only one notification (read or write) as
opposed to both; used to implement C{removeReader} and C{removeWriter}.
@param fd: a file descriptor
@type fd: C{int}
@param descr: an L{IReadDescriptor} or L{IWriteDescriptor}
@param flag: C{kCFSocketWriteCallBack} C{kCFSocketReadCallBack}
"""
if id(descr) not in self._idmap:
return
if fd == -1:
# need to deal with it in this case, I think.
realfd = self._idmap[id(descr)]
else:
realfd = fd
src, cfs, descr, rw = self._fdmap[realfd]
CFSocketDisableCallBacks(cfs, flag)
rw[self._flag2idx(flag)] = False
if not rw[_READ] and not rw[_WRITE]:
del self._idmap[id(descr)]
del self._fdmap[realfd]
CFRunLoopRemoveSource(self._cfrunloop, src, kCFRunLoopCommonModes)
CFSocketInvalidate(cfs)
def _watchFD(self, fd, descr, flag):
"""
Register a file descriptor with the C{CFRunLoop}, or modify its state
so that it's listening for both notifications (read and write) rather
than just one; used to implement C{addReader} and C{addWriter}.
@param fd: The file descriptor.
@type fd: L{int}
@param descr: the L{IReadDescriptor} or L{IWriteDescriptor}
@param flag: the flag to register for callbacks on, either
C{kCFSocketReadCallBack} or C{kCFSocketWriteCallBack}
"""
if fd == -1:
raise RuntimeError("Invalid file descriptor.")
if fd in self._fdmap:
src, cfs, gotdescr, rw = self._fdmap[fd]
# do I need to verify that it's the same descr?
else:
ctx = []
ctx.append(fd)
cfs = CFSocketCreateWithNative(
kCFAllocatorDefault,
fd,
kCFSocketReadCallBack
| kCFSocketWriteCallBack
| kCFSocketConnectCallBack,
self._socketCallback,
ctx,
)
CFSocketSetSocketFlags(
cfs,
kCFSocketAutomaticallyReenableReadCallBack
| kCFSocketAutomaticallyReenableWriteCallBack
|
# This extra flag is to ensure that CF doesn't (destructively,
# because destructively is the only way to do it) retrieve
# SO_ERROR and thereby break twisted.internet.tcp.BaseClient,
# which needs SO_ERROR to tell it whether or not it needs to
# call connect_ex a second time.
_preserveSOError,
)
src = CFSocketCreateRunLoopSource(kCFAllocatorDefault, cfs, 0)
ctx.append(src)
CFRunLoopAddSource(self._cfrunloop, src, kCFRunLoopCommonModes)
CFSocketDisableCallBacks(
cfs,
kCFSocketReadCallBack
| kCFSocketWriteCallBack
| kCFSocketConnectCallBack,
)
rw = [False, False]
self._idmap[id(descr)] = fd
self._fdmap[fd] = src, cfs, descr, rw
rw[self._flag2idx(flag)] = True
CFSocketEnableCallBacks(cfs, flag)
