Reduce footprint of :fd property.

Querying the :fd stream property is equivalent to calling the
stream-fd function. Streams have a C virtual function get_fd,
so implementing :fd in their getprop functions is redundant
functionality.  The stream-getprop function can test for
:fd and call stream-fd, so the stream implementations don't
have to deal with the :fd property.

Also, there are still places in the code base that are using
stream_getprop to get the file descriptor, instead of calling
stream_fd.

If we fix all this, then fd_k remains referenced only in
a very small number of places.

* socket.c (dgram_get_prop): Don't handle :fd any more.

* stream.c (unimpl_get_fd): Static function removed.
(fill_stream_ops): Default the get_fd function to null_get_fd
instead of unimpl_get_fd, so it doesn't throw.
Even a stdio stream don't throw; when the file is closed,
it returns nil.
(stdio_get_prop): Don't handle :fd any more.
(stream_get_prop): Handle :fd here. If the stream has a get_fd
function that isn't null_get_fd, then call it. Only if the
stream doesn't have a get_fd function, fall back on its
get_prop function.

* sysif.c (mkdir_wrap, poll_wrap, simulate_setuid_setgid):
Call stream_fd instead of stream_get_prop.

1 files changed, 0 insertions, 3 deletions

diff --git a/socket.c b/socket.c
index cda85e7e..9b213e4f 100644
--- a/socket.c
+++ b/socket.c
@@ -552,9 +552,6 @@ static val dgram_get_prop(val stream, val ind)
 {
   struct dgram_stream *d = coerce(struct dgram_stream *, stream->co.handle);
 
-  if (ind == fd_k)
-    return num(d->fd);
-
   if (ind == name_k) {
     if (d->fd == -1)
       return lit("closed");