NNG_OPT_RECVFD and NNG_OPT_SENDFD converted to functions.

These options are removed entirely, and their functionality is now
available via special functions, `nng_socket_get_send_poll_fd` and
`nng_socket_get_recv_poll_fd`, making these first class methods on
the socket.

This eliminates a bit of wasteful code, and provides type safety
for these methods.

4 files changed, 31 insertions, 48 deletions

diff --git a/src/core/protocol.h b/src/core/protocol.h
index c7bfb1ad..0d4d12dc 100644
--- a/src/core/protocol.h
+++ b/src/core/protocol.h
@@ -108,6 +108,12 @@ struct nni_proto_sock_ops {
 	// Receive a message.
 	void (*sock_recv)(void *, nni_aio *);
 
+	// Return the receive poll FD.
+	int (*sock_recv_poll_fd)(void *, int *);
+
+	// Return the send poll FD.
+	int (*sock_send_poll_fd)(void *, int *);
+
 	// Options. Must not be NULL. Final entry should have NULL name.
 	nni_option *sock_options;
 };
@@ -124,7 +130,7 @@ struct nni_proto {
 	uint32_t                  proto_flags;    // Protocol flags
 	const nni_proto_sock_ops *proto_sock_ops; // Per-socket operations
 	const nni_proto_pipe_ops *proto_pipe_ops; // Per-pipe operations
-	const nni_proto_ctx_ops * proto_ctx_ops;  // Context operations
+	const nni_proto_ctx_ops  *proto_ctx_ops;  // Context operations
 };
 
 // We quite intentionally use a signature where the upper word is nonzero,
diff --git a/src/core/sock_test.c b/src/core/sock_test.c
index f785d9c0..7641ea1f 100644
--- a/src/core/sock_test.c
+++ b/src/core/sock_test.c
@@ -79,16 +79,6 @@ test_send_nonblock(void)
 }
 
 void
-test_readonly_options(void)
-{
-	nng_socket s1;
-	NUTS_OPEN(s1);
-	NUTS_FAIL(nng_socket_set_int(s1, NNG_OPT_RECVFD, 0), NNG_EREADONLY);
-	NUTS_FAIL(nng_socket_set_int(s1, NNG_OPT_SENDFD, 0), NNG_EREADONLY);
-	NUTS_CLOSE(s1);
-}
-
-void
 test_socket_base(void)
 {
 	nng_socket s1 = NNG_SOCKET_INITIALIZER;
@@ -596,7 +586,6 @@ NUTS_TESTS = {
 	{ "recv non-block", test_recv_nonblock },
 	{ "send timeout", test_send_timeout },
 	{ "send non-block", test_send_nonblock },
-	{ "read only options", test_readonly_options },
 	{ "socket base", test_socket_base },
 	{ "socket name", test_socket_name },
 	{ "socket name oversize", test_socket_name_oversize },
diff --git a/src/core/socket.c b/src/core/socket.c
index 88a11382..9376f9de 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -114,19 +114,19 @@ static void nni_ctx_destroy(nni_ctx *);
 #define SOCK(s) ((nni_sock *) (s))
 
 static int
-sock_get_fd(void *s, unsigned flag, int *fdp)
+sock_get_fd(nni_sock *s, unsigned flag, int *fdp)
 {
 	int           rv;
 	nni_pollable *p;
 
-	if ((flag & nni_sock_flags(SOCK(s))) == 0) {
+	if ((flag & nni_sock_flags(s)) == 0) {
 		return (NNG_ENOTSUP);
 	}
 
 	if (flag == NNI_PROTO_FLAG_SND) {
-		rv = nni_msgq_get_sendable(SOCK(s)->s_uwq, &p);
+		rv = nni_msgq_get_sendable(s->s_uwq, &p);
 	} else {
-		rv = nni_msgq_get_recvable(SOCK(s)->s_urq, &p);
+		rv = nni_msgq_get_recvable(s->s_urq, &p);
 	}
 
 	if (rv == 0) {
@@ -137,30 +137,6 @@ sock_get_fd(void *s, unsigned flag, int *fdp)
 }
 
 static int
-sock_get_sendfd(void *s, void *buf, size_t *szp, nni_type t)
-{
-	int fd;
-	int rv;
-
-	if ((rv = sock_get_fd(SOCK(s), NNI_PROTO_FLAG_SND, &fd)) != 0) {
-		return (rv);
-	}
-	return (nni_copyout_int(fd, buf, szp, t));
-}
-
-static int
-sock_get_recvfd(void *s, void *buf, size_t *szp, nni_type t)
-{
-	int fd;
-	int rv;
-
-	if ((rv = sock_get_fd(SOCK(s), NNI_PROTO_FLAG_RCV, &fd)) != 0) {
-		return (rv);
-	}
-	return (nni_copyout_int(fd, buf, szp, t));
-}
-
-static int
 sock_get_raw(void *s, void *buf, size_t *szp, nni_type t)
 {
 	bool raw = ((nni_sock_flags(SOCK(s)) & NNI_PROTO_FLAG_RAW) != 0);
@@ -287,14 +263,6 @@ static const nni_option sock_options[] = {
 	    .o_set  = sock_set_sendtimeo,
 	},
 	{
-	    .o_name = NNG_OPT_RECVFD,
-	    .o_get  = sock_get_recvfd,
-	},
-	{
-	    .o_name = NNG_OPT_SENDFD,
-	    .o_get  = sock_get_sendfd,
-	},
-	{
 	    .o_name = NNG_OPT_RECVBUF,
 	    .o_get  = sock_get_recvbuf,
 	    .o_set  = sock_set_recvbuf,
@@ -353,6 +321,24 @@ nni_sock_id(nni_sock *s)
 	return (s->s_id);
 }
 
+int
+nni_sock_get_send_fd(nni_sock *s, int *fdp)
+{
+	if (s->s_sock_ops.sock_send_poll_fd != NULL) {
+		return (s->s_sock_ops.sock_send_poll_fd(s->s_data, fdp));
+	}
+	return (sock_get_fd(s, NNI_PROTO_FLAG_SND, fdp));
+}
+
+int
+nni_sock_get_recv_fd(nni_sock *s, int *fdp)
+{
+	if (s->s_sock_ops.sock_recv_poll_fd != NULL) {
+		return (s->s_sock_ops.sock_recv_poll_fd(s->s_data, fdp));
+	}
+	return (sock_get_fd(s, NNI_PROTO_FLAG_RCV, fdp));
+}
+
 // nni_sock_sendq and nni_sock_recvq are called by the protocol to obtain
 // the upper read and write queues.
 nni_msgq *
diff --git a/src/core/socket.h b/src/core/socket.h
index c4037e96..714ad5bb 100644
--- a/src/core/socket.h
+++ b/src/core/socket.h
@@ -34,6 +34,8 @@ extern int nni_sock_getopt(
 extern void     nni_sock_send(nni_sock *, nni_aio *);
 extern void     nni_sock_recv(nni_sock *, nni_aio *);
 extern uint32_t nni_sock_id(nni_sock *);
+extern int      nni_sock_get_send_fd(nni_sock *s, int *fdp);
+extern int      nni_sock_get_recv_fd(nni_sock *s, int *fdp);
 
 // These are socket methods that protocol operations can expect to call.
 // Note that each of these should be called without any locks held, since