According to the kqueue man page, kevent()
should create an event when the socket has shutdown. From the description of th filter EVFILT_READ
:
EVFILT_READ
Takes a descriptor as the identifier, and returns whenever there is data available to read. The behavior of the filter is slightly different depending on the descriptor type.
Sockets
Sockets which have previously been passed to listen() return when there is an incoming connection pending. data contains the size of the listen backlog.
Other socket descriptors return when there is data to be read, subject to the SO_RCVLOWAT value of the socket buffer. This may be overridden with a per-filter low water mark at the time the filter is added by setting the NOTE_LOWAT flag in fflags, and specifying the new low water mark in data. On return, data contains the number of bytes of protocol data available to read.
If the read direction of the socket has shutdown, then the filter also sets EV_EOF in flags, and returns the socket error (if any) in fflags. It is possible for EOF to be returned (indicating the connection is gone) while there is still data pending in the socket buffer.