fixes #381 Want comparators for various types

28 files changed, 494 insertions, 99 deletions

diff --git a/docs/man/libnng.3.adoc b/docs/man/libnng.3.adoc
index 8df29861..149dc9f4 100644
--- a/docs/man/libnng.3.adoc
+++ b/docs/man/libnng.3.adoc
@@ -49,6 +49,7 @@ The following functions operate on sockets.
 |<<nng_recv.3#,nng_recv()>>|receive data
 |<<nng_send.3#,nng_send()>>|send data
 |<<nng_setopt.3#,nng_setopt()>>|set socket option
+|<<nng_socket_id.3#,nng_socket_id()>>|get numeric socket identifier
 |===
 
 === Connection Management
@@ -61,16 +62,19 @@ Listeners accept incoming connection requets, and dialers make them.
 |<<nng_dialer_close.3#,nng_dialer_close()>>|close dialer
 |<<nng_dialer_create.3#,nng_dialer_create()>>|create dialer
 |<<nng_dialer_getopt.3#,nng_dialer_getopt()>>|get dialer option
+|<<nng_dialer_id.3#,nng_dialer_id()>>|get numeric dialer identifier
 |<<nng_dialer_setopt.3#,nng_dialer_setopt()>>|set dialer option
 |<<nng_dialer_start.3#,nng_dialer_start()>>|start dialer
 |<<nng_listen.3#,nng_listen()>>|create and start listener
 |<<nng_listener_close.3#,nng_listener_close()>>|close listener
 |<<nng_listener_create.3#,nng_listener_create()>>|create listener
 |<<nng_listener_getopt.3#,nng_listener_getopt()>>|get listener option
+|<<nng_listener_id.3#,nng_listener_id()>>|get numeric listener identifier
 |<<nng_listener_setopt.3#,nng_listener_setopt()>>|set listener option
 |<<nng_listener_start.3#,nng_listener_start()>>|start listener
 |<<nng_pipe_close.3#,nng_pipe_close()>>|close pipe
 |<<nng_pipe_getopt.3#,nng_pipe_getopt()>>|get pipe option
+|<<nng_pipe_id.3#,nng_pipe_id()>>|get numeric pipe identifier
 |===
 
 === Message Handling Functions
@@ -205,6 +209,7 @@ concurrent applications.
 |===
 |<<nng_ctx_close.3#,nng_ctx_close()>>|close context
 |<<nng_ctx_getopt.3#,nng_ctx_getopt()>>|get context option
+|<<nng_ctx_id.3#,nng_ctx_id()>>|get numeric context identifier
 |<<nng_ctx_open.3#,nng_ctx_open()>>|create context
 |<<nng_ctx_recv.3#,nng_ctx_recv()>>|receive message using context asynchronously
 |<<nng_ctx_send.3#,nng_ctx_send()>>|send message using context asynchronously
diff --git a/docs/man/nng_ctx.5.adoc b/docs/man/nng_ctx.5.adoc
index 98402738..ada117c3 100644
--- a/docs/man/nng_ctx.5.adoc
+++ b/docs/man/nng_ctx.5.adoc
@@ -81,6 +81,12 @@ are in use on the same socket is not supported, and may lead to unpredictable
 behavior.
 These asynchronous methods should not be mixed on the same socket.
 
+[[NNG_CTX_INITIALIZER]]
+=== Initialization
+
+A context may be initialized using the macro `NNG_CTX_INITIALIZER`
+before it is opened, to prevent confusion with valid open contexts.
+
 == EXAMPLE
 
 The following program fragment demonstrates the use of contexts to implement
@@ -91,7 +97,7 @@ to the sender.
 ----
 
 struct echo_context {
-    nng_ctx *ctx;
+    nng_ctx ctx;
     nng_aio *aio;
     enum { INIT, RECV, SEND } state;
 };
@@ -156,6 +162,7 @@ start_echo_service(nng_socket rep_socket)
 <<nng_ctx_close.3#,nng_ctx_close(3)>>,
 <<nng_ctx_open.3#,nng_ctx_open(3)>>,
 <<nng_ctx_getopt.3#,nng_ctx_getopt(3)>>,
+<<nng_ctx_id.3#,nng_ctx_id(3)>>,
 <<nng_ctx_recv.3#,nng_ctx_recv(3)>>,
 <<nng_ctx_send.3#,nng_ctx_send(3)>>,
 <<nng_ctx_setopt.3#,nng_ctx_setopt(3)>>,
diff --git a/docs/man/nng_ctx_id.3.adoc b/docs/man/nng_ctx_id.3.adoc
new file mode 100644
index 00000000..56d9d7bd
--- /dev/null
+++ b/docs/man/nng_ctx_id.3.adoc
@@ -0,0 +1,50 @@
+= nng_ctx_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_ctx_id - return numeric context identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_ctx_id(nng_ctx c);
+----
+
+== DESCRIPTION
+
+The `nng_ctx_id()` function returns a positive identifier for the context _c_,
+if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A context is considered valid if it was ever opened with
+<<nng_ctx_open.3#,`nng_ctx_open`>> function.
+Contexts that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_ctx.5#NNG_CTX_INITIALIZER,`NNG_CTX_INITIALIZER`>> to ensure that
+they cannot be confused with a valid context before they are opened.
+
+== RETURN VALUES
+
+This function returns the positive value for the context identifier, or
+`-1` if the context is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_ctx.5#,nng_ctx(5)>>,
+<<nng.7#,nng(7)>>
diff --git a/docs/man/nng_dialer.5.adoc b/docs/man/nng_dialer.5.adoc
index 45c60bc9..3f742c21 100644
--- a/docs/man/nng_dialer.5.adoc
+++ b/docs/man/nng_dialer.5.adoc
@@ -58,12 +58,19 @@ Dialer objects may be destroyed by the
 <<nng_dialer_close.3#,`nng_pipe_close()`>> function.
 They are also closed when their "`owning`" socket is closed.
 
+[[NNG_DIALER_INITIALIZER]]
+=== Initialization
+
+A dialer may be initialized using the macro `NNG_DIALER_INITIALIZER`
+before it is opened, to prevent confusion with valid open dialers.
+
 == SEE ALSO
 
 <<nng_dial.3#,nng_dial(3)>>,
 <<nng_dialer_close.3#,nng_dialer_close(3)>>,
 <<nng_dialer_create.3#,nng_dialer_create(3)>>,
 <<nng_dialer_getopt.3#,nng_dialer_getopt(3)>>,
+<<nng_dialer_id.3#,nng_dialer_id(3)>>,
 <<nng_dialer_setopt.3#,nng_dialer_setopt(3)>>,
 <<nng_dialer_start.3#,nng_dialer_start(3)>>,
 <<nng_listener.5#,nng_listener(5)>>,
diff --git a/docs/man/nng_dialer_id.3.adoc b/docs/man/nng_dialer_id.3.adoc
new file mode 100644
index 00000000..cf8936b5
--- /dev/null
+++ b/docs/man/nng_dialer_id.3.adoc
@@ -0,0 +1,51 @@
+= nng_dialer_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_dialer_id - return numeric dialer identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_dialer_id(nng_dialer d);
+----
+
+== DESCRIPTION
+
+The `nng_dialer_id()` function returns a positive identifier for the dialer _d_,
+if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A dialer is considered valid if it was ever created with the
+<<nng_dialer_create.3#,`nng_dialer_create`>> or
+<<nng_dial.3#,`nng_dial`>> functions.
+Dialers that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_ctx.5#NNG_DIALER_INITIALIZER,`NNG_DIALER_INITIALIZER`>> to ensure that
+they cannot be confused with a valid dialer before they are created properly.
+
+== RETURN VALUES
+
+This function returns the positive value for the dialer identifier, or
+`-1` if the dialer is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_dialer.5#,nng_dialer(5)>>,
+<<nng.7#,nng(7)>>
diff --git a/docs/man/nng_listener.5.adoc b/docs/man/nng_listener.5.adoc
index 558eb920..e7187a61 100644
--- a/docs/man/nng_listener.5.adoc
+++ b/docs/man/nng_listener.5.adoc
@@ -55,12 +55,19 @@ Listener objects may be destroyed by the
 <<nng_listener_close.3#,`nng_listener_close()`>> function.
 They are also closed when their "`owning`" socket is closed.
 
+[[NNG_LISTENER_INITIALIZER]]
+=== Initialization
+
+A listener may be initialized using the macro `NNG_LISTENER_INITIALIZER`
+before it is opened, to prevent confusion with valid open listener.
+
 == SEE ALSO
 
 <<nng_listen.3#,nng_listen(3)>>,
 <<nng_listener_close.3#,nng_listener_close(3)>>,
 <<nng_listener_create.3#,nng_listener_create(3)>>,
 <<nng_listener_getopt.3#,nng_listener_getopt(3)>>,
+<<nng_listener_id.3#,nng_listener_id(3)>>,
 <<nng_listener_setopt.3#,nng_listener_setopt(3)>>,
 <<nng_listener_start.3#,nng_listener_start(3)>>,
 <<nng_dialer.5#,nng_dialer(5)>>,
diff --git a/docs/man/nng_listener_id.3.adoc b/docs/man/nng_listener_id.3.adoc
new file mode 100644
index 00000000..44404e14
--- /dev/null
+++ b/docs/man/nng_listener_id.3.adoc
@@ -0,0 +1,51 @@
+= nng_listener_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_listener_id - return numeric listener identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_listener_id(nng_listener l);
+----
+
+== DESCRIPTION
+
+The `nng_listener_id()` function returns a positive identifier for the
+listener _l_, if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A listener is considered valid if it was ever created with the
+<<nng_listener_create.3#,`nng_listener_create`>> or
+<<nng_listen.3#,`nng_listen`>> functions.
+listeners that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_ctx.5#NNG_LISTENER_INITIALIZER,`NNG_LISTENER_INITIALIZER`>> to ensure that
+they cannot be confused with a valid listener before they are created properly.
+
+== RETURN VALUES
+
+This function returns the positive value for the listener identifier, or
+`-1` if the listener is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_listener.5#,nng_listener(5)>>,
+<<nng.7#,nng(7)>>
diff --git a/docs/man/nng_pipe.5.adoc b/docs/man/nng_pipe.5.adoc
index 39247fbd..a7423884 100644
--- a/docs/man/nng_pipe.5.adoc
+++ b/docs/man/nng_pipe.5.adoc
@@ -51,11 +51,25 @@ Pipe objects may be destroyed by the
 They are also closed when their "`owning`" dialer or listener is closed,
 or when the remote peer closes the underlying connection.
 
+[[NNG_PIPE_INITIALIZER]]
+=== Initialization
+
+A pipe may be initialized using the macro `NNG_PIPE_INITIALIZER`
+before it is opened, to prevent confusion with valid open pipes.
+
+For example:
+
+[source, c]
+----
+nng_pipe p = NNG_PIPE_INITIALIZER;
+----
+
 == SEE ALSO
 
 <<nng_msg_get_pipe.3#,nng_msg_get_pipe(3)>>,
 <<nng_pipe_close.3#,nng_pipe_close(3)>>,
 <<nng_pipe_getopt.3#,nng_pipe_getopt(3)>>,
+<<nng_pipe_id.3#,nng_pipe_id(3)>>,
 <<nng_dialer.5#,nng_dialer(5)>>,
 <<nng_listener.5#,nng_listener(5)>>,
 <<nng_options.5#,nng_options(5)>>,
diff --git a/docs/man/nng_pipe_close.3.adoc b/docs/man/nng_pipe_close.3.adoc
index 598e143a..2128caec 100644
--- a/docs/man/nng_pipe_close.3.adoc
+++ b/docs/man/nng_pipe_close.3.adoc
@@ -19,7 +19,7 @@ nng_pipe_close - close pipe
 ----
 #include <nng/nng.h>
 
-int nng_pipe_close(nng_socket s);
+int nng_pipe_close(nng_pipe p);
 ----
 
 == DESCRIPTION
diff --git a/docs/man/nng_pipe_id.3.adoc b/docs/man/nng_pipe_id.3.adoc
new file mode 100644
index 00000000..b327dac2
--- /dev/null
+++ b/docs/man/nng_pipe_id.3.adoc
@@ -0,0 +1,50 @@
+= nng_pipe_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_pipe_id - return numeric pipe identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_pipe_id(nng_pipe p);
+----
+
+== DESCRIPTION
+
+The `nng_pipe_id()` function returns a positive identifier for the pipe _p_,
+if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A pipe is considered valid if it was ever opened with
+<<nng_pipe_open.3#,`nng_pipe_open`>> function.
+Pipes that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_pipe.5#NNG_PIPE_INITIALIZER,`NNG_PIPE_INITIALIZER`>> to ensure that
+they cannot be confused with a valid pipe before they are opened.
+
+== RETURN VALUES
+
+This function returns the positive value for the pipe identifier, or
+`-1` if the pipe is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_pipe.5#,nng_pipe(5)>>,
+<<nng.7#,nng(7)>>
diff --git a/docs/man/nng_socket.5.adoc b/docs/man/nng_socket.5.adoc
index 4711495f..2d8d7256 100644
--- a/docs/man/nng_socket.5.adoc
+++ b/docs/man/nng_socket.5.adoc
@@ -44,12 +44,26 @@ Each `nng_socket` is created by a protocol-specific constructor, such as
 When the socket is no longer needed, it can be closed with
 <<nng_close.3#,`nng_close()`>>.
 
+[[NNG_SOCKET_INITIALIZER]]
+=== Initialization
+
+A socket may be initialized using the macro `NNG_SOCKET_INITIALIZER`
+before it is opened, to prevent confusion with valid open sockets.
+
+For example:
+
+[source, c]
+----
+nng_socket s = NNG_SOCKET_INITIALIZER;
+----
+
 == SEE ALSO
 
 <<libnng.3#,libnng(3)>>,
 <<nng_close.3#,nng_close(3)>>,
 <<nng_getopt.3#,nng_getopt(3)>>,
 <<nng_setopt.3#,nng_setopt(3)>>,
+<<nng_socket_id.3#,nng_socket_id(3)>>,
 <<nng_dialer.5#,nng_dialer(5)>>,
 <<nng_listener.5#,nng_listener(5)>>,
 <<nng_options.5#,nng_options(5)>>,
diff --git a/docs/man/nng_socket_id.3.adoc b/docs/man/nng_socket_id.3.adoc
new file mode 100644
index 00000000..b5acc98b
--- /dev/null
+++ b/docs/man/nng_socket_id.3.adoc
@@ -0,0 +1,50 @@
+= nng_socket_id(3)
+//
+// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2018 Capitar IT Group BV <info@capitar.com>
+//
+// This document is supplied under the terms of the MIT License, a
+// copy of which should be located in the distribution where this
+// file was obtained (LICENSE.txt).  A copy of the license may also be
+// found online at https://opensource.org/licenses/MIT.
+//
+
+== NAME
+
+nng_socket_id - return numeric socket identifier
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_socket_id(nng_socket s);
+----
+
+== DESCRIPTION
+
+The `nng_socket_id()` function returns a positive identifier for the socket _s_,
+if it is valid.
+Otherwise it returns `-1`.
+
+NOTE: A socket is considered valid if it was ever opened with a protocol
+constructor, such as the <<nng_req0_open.3#,`nng_req0_open`>> function.
+Sockets that are allocated on the stack or statically should be
+initialized with the macro
+<<nng_socket.5#NNG_SOCKET_INITIALIZER,`NNG_SOCKET_INITIALIZER`>> to ensure that
+they cannot be confused with a valid socket before they are opened.
+
+== RETURN VALUES
+
+This function returns the positive value for the socket identifier, or
+`-1` if the socket is invalid.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng_socket.5#,nng_socket(5)>>,
+<<nng.7#,nng(7)>>
diff --git a/src/core/pipe.c b/src/core/pipe.c
index a4148c65..c619fca0 100644
--- a/src/core/pipe.c
+++ b/src/core/pipe.c
@@ -26,7 +26,7 @@ struct nni_pipe {
 	nni_list_node p_ep_node;
 	nni_sock *    p_sock;
 	nni_ep *      p_ep;
-	int           p_reap;
+	bool          p_reap;
 	int           p_stop;
 	int           p_refcnt;
 	nni_mtx       p_mtx;
@@ -142,8 +142,12 @@ nni_pipe_find(nni_pipe **pp, uint32_t id)
 	nni_pipe *p;
 	nni_mtx_lock(&nni_pipe_lk);
 	if ((rv = nni_idhash_find(nni_pipes, id, (void **) &p)) == 0) {
-		p->p_refcnt++;
-		*pp = p;
+		if (p->p_reap) {
+			rv = NNG_ECLOSED;
+		} else {
+			p->p_refcnt++;
+			*pp = p;
+		}
 	}
 	nni_mtx_unlock(&nni_pipe_lk);
 	return (rv);
@@ -186,12 +190,12 @@ void
 nni_pipe_close(nni_pipe *p)
 {
 	nni_mtx_lock(&p->p_mtx);
-	if (p->p_reap == 1) {
+	if (p->p_reap) {
 		// We already did a close.
 		nni_mtx_unlock(&p->p_mtx);
 		return;
 	}
-	p->p_reap = 1;
+	p->p_reap = true;
 
 	// Close the underlying transport.
 	if (p->p_tran_data != NULL) {
@@ -267,6 +271,7 @@ nni_pipe_create(nni_ep *ep, void *tdata)
 	p->p_proto_data = NULL;
 	p->p_ep         = ep;
 	p->p_sock       = sock;
+	p->p_reap       = false;
 
 	NNI_LIST_NODE_INIT(&p->p_reap_node);
 	NNI_LIST_NODE_INIT(&p->p_sock_node);
diff --git a/src/nng.c b/src/nng.c
index a4b8fd27..4dc6c3fa 100644
--- a/src/nng.c
+++ b/src/nng.c
@@ -46,6 +46,12 @@ nng_close(nng_socket s)
 	return (rv);
 }
 
+int
+nng_socket_id(nng_socket s)
+{
+	return (((int) s.id > 0) ? (int) s.id : -1);
+}
+
 void
 nng_closeall(void)
 {
@@ -230,12 +236,12 @@ nng_send_aio(nng_socket s, nng_aio *aio)
 }
 
 int
-nng_ctx_open(nng_ctx *idp, nng_socket s)
+nng_ctx_open(nng_ctx *cp, nng_socket s)
 {
 	nni_sock *sock;
 	nni_ctx * ctx;
 	int       rv;
-	nng_ctx   id;
+	nng_ctx   c;
 
 	if ((rv = nni_sock_find(&sock, s.id)) != 0) {
 		return (rv);
@@ -244,20 +250,20 @@ nng_ctx_open(nng_ctx *idp, nng_socket s)
 		nni_sock_rele(sock);
 		return (rv);
 	}
-	id.id = nni_ctx_id(ctx);
-	*idp  = id;
+	c.id = nni_ctx_id(ctx);
 	nni_ctx_rele(ctx);
 	nni_sock_rele(sock);
+	*cp = c;
 	return (0);
 }
 
 int
-nng_ctx_close(nng_ctx cid)
+nng_ctx_close(nng_ctx c)
 {
 	int      rv;
 	nni_ctx *ctx;
 
-	if ((rv = nni_ctx_find(&ctx, cid.id, true)) != 0) {
+	if ((rv = nni_ctx_find(&ctx, c.id, true)) != 0) {
 		return (rv);
 	}
 	// no release, close releases implicitly.
@@ -265,6 +271,12 @@ nng_ctx_close(nng_ctx cid)
 	return (0);
 }
 
+int
+nng_ctx_id(nng_ctx c)
+{
+	return (((int) c.id > 0) ? (int) c.id : -1);
+}
+
 void
 nng_ctx_recv(nng_ctx cid, nng_aio *aio)
 {
@@ -497,6 +509,12 @@ nng_listener_start(nng_listener l, int flags)
 }
 
 int
+nng_listener_id(nng_listener l)
+{
+	return (((int) l.id > 0) ? (int) l.id : -1);
+}
+
+int
 nng_dialer_create(nng_dialer *dp, nng_socket s, const char *addr)
 {
 	nni_sock * sock;
@@ -532,6 +550,12 @@ nng_dialer_start(nng_dialer d, int flags)
 	return (rv);
 }
 
+int
+nng_dialer_id(nng_dialer d)
+{
+	return (((int) d.id > 0) ? (int) d.id : -1);
+}
+
 static int
 nng_ep_setx(
     uint32_t id, const char *n, const void *v, size_t sz, int mode, int t)
@@ -1088,19 +1112,19 @@ nng_strerror(int num)
 }
 
 static int
-nng_pipe_getx(nng_pipe id, const char *name, void *val, size_t *szp, int t)
+nng_pipe_getx(nng_pipe p, const char *name, void *val, size_t *szp, int t)
 {
 	int       rv;
-	nni_pipe *p;
+	nni_pipe *pipe;
 
 	if ((rv = nni_init()) < 0) {
 		return (rv);
 	}
-	if ((rv = nni_pipe_find(&p, id.id)) != 0) {
+	if ((rv = nni_pipe_find(&pipe, p.id)) != 0) {
 		return (rv);
 	}
-	rv = nni_pipe_getopt(p, name, val, szp, t);
-	nni_pipe_rele(p);
+	rv = nni_pipe_getopt(pipe, name, val, szp, t);
+	nni_pipe_rele(pipe);
 	return (rv);
 }
 
@@ -1167,19 +1191,25 @@ nng_pipe_getopt_string(nng_pipe p, const char *name, char **valp)
 }
 
 int
-nng_pipe_close(nng_pipe pid)
+nng_pipe_close(nng_pipe p)
 {
 	int       rv;
-	nni_pipe *p;
+	nni_pipe *pipe;
 
-	if ((rv = nni_pipe_find(&p, pid.id)) != 0) {
+	if ((rv = nni_pipe_find(&pipe, p.id)) != 0) {
 		return (rv);
 	}
-	nni_pipe_close(p);
-	nni_pipe_rele(p);
+	nni_pipe_close(pipe);
+	nni_pipe_rele(pipe);
 	return (0);
 }
 
+int
+nng_pipe_id(nng_pipe p)
+{
+	return (((int) p.id > 0) ? (int) p.id : -1);
+}
+
 // Message handling.
 int
 nng_msg_alloc(nng_msg **msgp, size_t size)
diff --git a/src/nng.h b/src/nng.h
index f45c5bff..c3ae48ac 100644
--- a/src/nng.h
+++ b/src/nng.h
@@ -92,6 +92,15 @@ typedef struct nng_snapshot nng_snapshot;
 typedef struct nng_stat     nng_stat;
 typedef struct nng_aio      nng_aio;
 
+// Initializers.
+// clang-format off
+#define NNG_PIPE_INITIALIZER { 0 }
+#define NNG_SOCKET_INITIALIZER { 0 }
+#define NNG_DIALER_INITIALIZER { 0 }
+#define NNG_LISTENER_INITIALIZER { 0 }
+#define NNG_CTX_INITIALIZER { 0 }
+// clang-format on
+
 // Some address details. This is in some ways like a traditional sockets
 // sockaddr, but we have our own to cope with our unique families, etc.
 // The details of this structure are directly exposed to applications.
@@ -181,6 +190,10 @@ NNG_DECL void nng_fini(void);
 // resources.
 NNG_DECL int nng_close(nng_socket);
 
+// nng_socket_id returns the positive socket id for the socket, or -1
+// if the socket is not valid.
+NNG_DECL int nng_socket_id(nng_socket);
+
 // nng_closeall closes all open sockets. Do not call this from
 // a library; it will affect all sockets.
 NNG_DECL void nng_closeall(void);
@@ -249,6 +262,14 @@ NNG_DECL int nng_dialer_close(nng_dialer);
 // connections and releasing all associated resources.
 NNG_DECL int nng_listener_close(nng_listener);
 
+// nng_dialer_id returns the positive dialer ID, or -1 if the dialer is
+// invalid.
+NNG_DECL int nng_dialer_id(nng_dialer);
+
+// nng_listener_id returns the positive listener ID, or -1 if the listener is
+// invalid.
+NNG_DECL int nng_listener_id(nng_listener);
+
 // nng_dialer_setopt sets an option for a specific dialer.  Note
 // dialer options may not be altered on a running dialer.
 NNG_DECL int nng_dialer_setopt(nng_dialer, const char *, const void *, size_t);
@@ -379,6 +400,11 @@ NNG_DECL int nng_ctx_open(nng_ctx *, nng_socket);
 // nng_ctx_close closes the context.
 NNG_DECL int nng_ctx_close(nng_ctx);
 
+// nng_ctx_id returns the numeric id for the context; this will be
+// a postive value for a valid context, or < 0 for an invalid context.
+// A valid context is not necessarily an *open* context.
+NNG_DECL int nng_ctx_id(nng_ctx);
+
 // nng_ctx_recv receives asynchronously.  It works like nng_recv_aio, but
 // uses a local context instead of the socket global context.
 NNG_DECL void nng_ctx_recv(nng_ctx, nng_aio *);
@@ -573,6 +599,7 @@ NNG_DECL int nng_pipe_getopt_uint64(nng_pipe, const char *, uint64_t *);
 NNG_DECL int nng_pipe_getopt_ptr(nng_pipe, const char *, void **);
 NNG_DECL int nng_pipe_getopt_string(nng_pipe, const char *, char **);
 NNG_DECL int nng_pipe_close(nng_pipe);
+NNG_DECL int nng_pipe_id(nng_pipe);
 
 // Flags.
 enum nng_flag_enum {
diff --git a/tests/message.c b/tests/message.c
index bf212b48..7f40cd38 100644
--- a/tests/message.c
+++ b/tests/message.c
@@ -113,13 +113,17 @@ TestMain("Message Tests", {
 		});
 
 		Convey("Pipe retrievals work", {
-			nng_pipe p;
+			nng_pipe p  = NNG_PIPE_INITIALIZER;
+			nng_pipe p0 = NNG_PIPE_INITIALIZER;
+
+			So(nng_pipe_id(p0) < 0);
 			p = nng_msg_get_pipe(msg);
-			So(p.id == 0);
-			p.id = 45;
+			So(nng_pipe_id(p) < 0);
+			memset(&p, 0x22, sizeof(p));
 			nng_msg_set_pipe(msg, p);
 			p = nng_msg_get_pipe(msg);
-			So(p.id == 45);
+			So(nng_pipe_id(p) != nng_pipe_id(p0));
+			So(nng_pipe_id(p) == 0x22222222);
 		});
 
 		Convey("Message realloc works", {
diff --git a/tests/pair1.c b/tests/pair1.c
index 8a27bc6e..c777725c 100644
--- a/tests/pair1.c
+++ b/tests/pair1.c
@@ -28,14 +28,13 @@
 TestMain("PAIRv1 protocol", {
 	const char * templ = "inproc://pairv1/%u";
 	char         addr[NNG_MAXADDRLEN + 1];
-	nng_socket   s1;
-	nng_socket   c1;
-	nng_socket   c2;
+	nng_socket   s1 = NNG_SOCKET_INITIALIZER;
+	nng_socket   c1 = NNG_SOCKET_INITIALIZER;
+	nng_socket   c2 = NNG_SOCKET_INITIALIZER;
 	nng_duration tmo;
 	uint32_t     v;
 	size_t       sz;
 
-	s1.id = c1.id = c2.id = 0;
 	atexit(nng_fini);
 
 	Convey("Given a few sockets", {
@@ -44,6 +43,13 @@ TestMain("PAIRv1 protocol", {
 		So(nng_pair1_open(&c1) == 0);
 		So(nng_pair1_open(&c2) == 0);
 
+		So(nng_socket_id(s1) > 0);
+		So(nng_socket_id(c1) > 0);
+		So(nng_socket_id(c2) > 0);
+		So(nng_socket_id(s1) != nng_socket_id(c1));
+		So(nng_socket_id(s1) != nng_socket_id(c2));
+		So(nng_socket_id(c1) != nng_socket_id(c2));
+
 		Reset({
 			nng_close(s1);
 			nng_close(c1);
@@ -211,7 +217,7 @@ TestMain("PAIRv1 protocol", {
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			CHECKSTR(msg, "ONE");
 			p1 = nng_msg_get_pipe(msg);
-			So(p1.id != 0);
+			So(nng_pipe_id(p1) > 0);
 			nng_msg_free(msg);
 
 			So(nng_msg_alloc(&msg, 0) == 0);
@@ -220,10 +226,10 @@ TestMain("PAIRv1 protocol", {
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			CHECKSTR(msg, "TWO");
 			p2 = nng_msg_get_pipe(msg);
-			So(p2.id != 0);
+			So(nng_pipe_id(p2) > 0);
 			nng_msg_free(msg);
 
-			So(p1.id != p2.id);
+			So(nng_pipe_id(p1) != nng_pipe_id(p2));
 
 			So(nng_msg_alloc(&msg, 0) == 0);
 
@@ -308,7 +314,7 @@ TestMain("PAIRv1 protocol", {
 		nng_msleep(20);
 
 		Convey("Send/recv work", {
-			nng_pipe p;
+			nng_pipe p = NNG_PIPE_INITIALIZER;
 			So(nng_msg_alloc(&msg, 0) == 0);
 			APPENDSTR(msg, "GAMMA");
 			So(nng_msg_header_append_u32(msg, 1) == 0);
@@ -316,7 +322,8 @@ TestMain("PAIRv1 protocol", {
 			So(nng_sendmsg(c1, msg, 0) == 0);
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			p = nng_msg_get_pipe(msg);
-			So(p.id != 0);
+			So(nng_pipe_id(p) > 0);
+
 			CHECKSTR(msg, "GAMMA");
 			So(nng_msg_header_len(msg) == sizeof(uint32_t));
 			So(nng_msg_header_trim_u32(msg, &hops) == 0);
@@ -332,7 +339,8 @@ TestMain("PAIRv1 protocol", {
 			So(nng_msg_header_len(msg) == sizeof(uint32_t));
 			So(nng_msg_header_trim_u32(msg, &hops) == 0);
 			p = nng_msg_get_pipe(msg);
-			So(p.id != 0);
+			So(nng_pipe_id(p) > 0);
+
 			So(hops == 2);
 			nng_msg_free(msg);
 		});
@@ -474,7 +482,7 @@ TestMain("PAIRv1 protocol", {
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			CHECKSTR(msg, "ONE");
 			p1 = nng_msg_get_pipe(msg);
-			So(p1.id != 0);
+			So(nng_pipe_id(p1) > 0);
 			So(nng_msg_header_trim_u32(msg, &hops) == 0);
 			So(hops == 1);
 			nng_msg_free(msg);
@@ -485,12 +493,12 @@ TestMain("PAIRv1 protocol", {
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			CHECKSTR(msg, "TWO");
 			p2 = nng_msg_get_pipe(msg);
-			So(p2.id != 0);
+			So(nng_pipe_id(p2) > 0);
 			So(nng_msg_header_trim_u32(msg, &hops) == 0);
 			So(hops == 1);
 			nng_msg_free(msg);
 
-			So(p1.id != p2.id);
+			So(nng_pipe_id(p1) != nng_pipe_id(p2));
 
 			So(nng_msg_alloc(&msg, 0) == 0);
 			nng_msg_set_pipe(msg, p1);
@@ -518,7 +526,7 @@ TestMain("PAIRv1 protocol", {
 			So(nng_recvmsg(s1, &msg, 0) == 0);
 			CHECKSTR(msg, "ONE");
 			p1 = nng_msg_get_pipe(msg);
-			So(p1.id != 0);
+			So(nng_pipe_id(p1) > 0);
 			nng_msg_free(msg);
 
 			nng_close(c1);
diff --git a/tests/reconnect.c b/tests/reconnect.c
index 4cd6cb3a..6b4e8586 100644
--- a/tests/reconnect.c
+++ b/tests/reconnect.c
@@ -96,7 +96,7 @@ TestMain("Reconnect works", {
 					CHECKSTR(msg, "again");
 					p2 = nng_msg_get_pipe(msg);
 					nng_msg_free(msg);
-					So(p2.id != p1.id);
+					So(nng_pipe_id(p2) != nng_pipe_id(p1));
 				});
 			});
 		});
diff --git a/tests/sock.c b/tests/sock.c
index d6e36235..37b713dd 100644
--- a/tests/sock.c
+++ b/tests/sock.c
@@ -333,10 +333,12 @@ TestMain("Socket Operations", {
 
 		Convey("Listening works", {
 			char *       a = "inproc://here";
-			nng_listener l;
+			nng_listener l = NNG_LISTENER_INITIALIZER;
+
+			So(nng_listener_id(l) < 0);
 			rv = nng_listen(s1, a, &l, 0);
 			So(rv == 0);
-			So(l.id != 0);
+			So(nng_listener_id(l) > 0);
 
 			Convey("Second listen fails ADDRINUSE", {
 				rv = nng_listen(s1, a, NULL, 0);
@@ -347,7 +349,8 @@ TestMain("Socket Operations", {
 			    { So(nng_listener_start(l, 0) == NNG_ESTATE); });
 
 			Convey("We can connect to it", {
-				nng_socket s2;
+				nng_socket s2 = NNG_SOCKET_INITIALIZER;
+				So(nng_socket_id(s2) < 0);
 				So(nng_pair_open(&s2) == 0);
 				Reset({ nng_close(s2); });
 				So(nng_dial(s2, a, NULL, 0) == 0);
@@ -356,9 +359,13 @@ TestMain("Socket Operations", {
 		});
 
 		Convey("Dialer creation ok", {
-			nng_dialer ep;
-			char *     a = "tcp://127.0.0.1:2929";
+			nng_dialer ep = NNG_DIALER_INITIALIZER;
+			char *     a  = "tcp://127.0.0.1:2929";
+
+			So(nng_dialer_id(ep) < 0);
 			So(nng_dialer_create(&ep, s1, a) == 0);
+			So(nng_dialer_id(ep) > 0);
+
 			Convey("Options work", {
 				size_t sz;
 				So(nng_dialer_setopt_size(
diff --git a/tests/surveyctx.c b/tests/surveyctx.c
index f4d8e703..aa36eca1 100644
--- a/tests/surveyctx.c
+++ b/tests/surveyctx.c
@@ -92,7 +92,7 @@ TestMain("Surveyor concurrent contexts", {
 	atexit(nng_fini);
 
 	Convey("We can use Surveyor contexts concurrently", {
-		nng_socket surv;
+		nng_socket surv = NNG_SOCKET_INITIALIZER;
 
 		So(nng_aio_alloc(&resp_state.aio, (void *) resp_cb, NULL) ==
 		    0);
@@ -145,6 +145,14 @@ TestMain("Surveyor concurrent contexts", {
 			if ((rv = nng_ctx_open(&ctxs[i], surv)) != 0) {
 				break;
 			}
+			if (nng_ctx_id(ctxs[i]) < 0) {
+				Fail("Invalid context ID");
+				break;
+			}
+			if ((i > 0) &&
+			    (nng_ctx_id(ctxs[i]) == nng_ctx_id(ctxs[i - 1]))) {
+				Fail("Context IDs not different");
+			}
 		}
 		So(rv == 0);
 		So(i == NCTX);
diff --git a/tests/tcp.c b/tests/tcp.c
index 3d2ecfc8..d29ceb8d 100644
--- a/tests/tcp.c
+++ b/tests/tcp.c
@@ -30,7 +30,7 @@ check_props_v4(nng_msg *msg)
 	bool         b;
 
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 	So(nng_pipe_getopt_sockaddr(p, NNG_OPT_LOCADDR, &la) == 0);
 	So(la.s_family == NNG_AF_INET);
 	So(la.s_in.sa_port == htons(trantest_port - 1));
diff --git a/tests/tcp6.c b/tests/tcp6.c
index 80135b33..c023997f 100644
--- a/tests/tcp6.c
+++ b/tests/tcp6.c
@@ -49,7 +49,7 @@ check_props_v6(nng_msg *msg)
 		nng_sockaddr la;
 		z = sizeof(nng_sockaddr);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt(p, NNG_OPT_LOCADDR, &la, &z) == 0);
 		So(z == sizeof(la));
 		So(la.s_family == NNG_AF_INET6);
@@ -62,7 +62,7 @@ check_props_v6(nng_msg *msg)
 		nng_sockaddr ra;
 		z = sizeof(nng_sockaddr);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt(p, NNG_OPT_REMADDR, &ra, &z) == 0);
 		So(z == sizeof(ra));
 		So(ra.s_family == NNG_AF_INET6);
diff --git a/tests/tls.c b/tests/tls.c
index 71e28deb..8ecf342a 100644
--- a/tests/tls.c
+++ b/tests/tls.c
@@ -114,7 +114,7 @@ check_props_v4(nng_msg *msg)
 	nng_sockaddr ra;
 
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 
 	// Typed access
 	So(nng_pipe_getopt_sockaddr(p, NNG_OPT_LOCADDR, &la) == 0);
@@ -426,7 +426,7 @@ TestMain("TLS Transport", {
 		So(nng_msg_len(msg) == 6);
 		So(strcmp(nng_msg_body(msg), "hello") == 0);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt_bool(p, NNG_OPT_TLS_VERIFIED, &b) == 0);
 		So(b == false);
 		nng_msg_free(msg);
@@ -468,7 +468,7 @@ TestMain("TLS Transport", {
 		So(nng_msg_len(msg) == 6);
 		So(strcmp(nng_msg_body(msg), "hello") == 0);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt_bool(p, NNG_OPT_TLS_VERIFIED, &b) == 0);
 		So(b == true);
 		int i;
diff --git a/tests/trantest.h b/tests/trantest.h
index ed1eccb7..de82099c 100644
--- a/tests/trantest.h
+++ b/tests/trantest.h
@@ -170,9 +170,8 @@ trantest_fini(trantest *tt)
 int
 trantest_dial(trantest *tt, nng_dialer *dp)
 {
-	nng_dialer d;
+	nng_dialer d = NNG_DIALER_INITIALIZER;
 	int        rv;
-	d.id = 0;
 
 	rv = nng_dialer_create(&d, tt->reqsock, tt->addr);
 	if (rv != 0) {
@@ -196,8 +195,7 @@ int
 trantest_listen(trantest *tt, nng_listener *lp)
 {
 	int          rv;
-	nng_listener l;
-	l.id = 0;
+	nng_listener l = NNG_LISTENER_INITIALIZER;
 
 	rv = nng_listener_create(&l, tt->repsock, tt->addr);
 	if (rv != 0) {
@@ -231,13 +229,12 @@ void
 trantest_conn_refused(trantest *tt)
 {
 	Convey("Connection refused works", {
-		nng_dialer d;
-		d.id = 0;
+		nng_dialer d = NNG_DIALER_INITIALIZER;
 
 		So(trantest_dial(tt, &d) == NNG_ECONNREFUSED);
-		So(d.id == 0);
+		So(nng_dialer_id(d) < 0);
 		So(trantest_dial(tt, &d) == NNG_ECONNREFUSED);
-		So(d.id == 0);
+		So(nng_dialer_id(d) < 0);
 	});
 }
 
@@ -245,14 +242,15 @@ void
 trantest_duplicate_listen(trantest *tt)
 {
 	Convey("Duplicate listen rejected", {
-		nng_listener l;
+		nng_listener l1 = NNG_LISTENER_INITIALIZER;
+		nng_listener l2 = NNG_LISTENER_INITIALIZER;
 		int          rv;
-		rv = trantest_listen(tt, &l);
+		rv = trantest_listen(tt, &l1);
 		So(rv == 0);
-		So(l.id != 0);
-		l.id = 0;
-		So(trantest_listen(tt, &l) == NNG_EADDRINUSE);
-		So(l.id == 0);
+		So(nng_listener_id(l1) > 0);
+		So(trantest_listen(tt, &l2) == NNG_EADDRINUSE);
+		So(nng_listener_id(l2) < 0);
+		So(nng_listener_id(l1) != nng_listener_id(l2));
 	});
 }
 
@@ -260,15 +258,16 @@ void
 trantest_listen_accept(trantest *tt)
 {
 	Convey("Listen and accept", {
-		nng_listener l;
-		nng_dialer   d;
+		nng_listener l  = NNG_LISTENER_INITIALIZER;
+		nng_dialer   d  = NNG_DIALER_INITIALIZER;
+		nng_dialer   d0 = NNG_DIALER_INITIALIZER;
 		So(trantest_listen(tt, &l) == 0);
-		So(l.id != 0);
+		So(nng_listener_id(l) > 0);
 
 		nng_msleep(200);
-		d.id = 0;
 		So(trantest_dial(tt, &d) == 0);
-		So(d.id != 0);
+		So(nng_dialer_id(d) > 0);
+		So(nng_dialer_id(d0) < 0);
 	});
 }
 
@@ -276,18 +275,19 @@ void
 trantest_send_recv(trantest *tt)
 {
 	Convey("Send and recv", {
-		nng_listener l;
-		nng_dialer   d;
+		nng_listener l = NNG_LISTENER_INITIALIZER;
+		nng_dialer   d = NNG_DIALER_INITIALIZER;
+		nng_pipe     p = NNG_PIPE_INITIALIZER;
 		nng_msg *    send;
 		nng_msg *    recv;
 		size_t       len;
-		nng_pipe     p;
 		char *       url;
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l.id != 0);
+		So(nng_listener_id(l) > 0);
+
 		So(trantest_dial(tt, &d) == 0);
-		So(d.id != 0);
+		So(nng_dialer_id(d) > 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -313,7 +313,7 @@ trantest_send_recv(trantest *tt)
 		So(nng_msg_len(recv) == strlen("acknowledge"));
 		So(strcmp(nng_msg_body(recv), "acknowledge") == 0);
 		p = nng_msg_get_pipe(recv);
-		So(p.id != 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt_string(p, NNG_OPT_URL, &url) == 0);
 		So(strcmp(url, tt->addr) == 0);
 		nng_strfree(url);
@@ -325,19 +325,19 @@ void
 trantest_send_recv_multi(trantest *tt)
 {
 	Convey("Send and recv multi", {
-		nng_listener l;
-		nng_dialer   d;
+		nng_listener l = NNG_LISTENER_INITIALIZER;
+		nng_dialer   d = NNG_DIALER_INITIALIZER;
+		nng_pipe     p = NNG_PIPE_INITIALIZER;
 		nng_msg *    send;
 		nng_msg *    recv;
-		nng_pipe     p;
 		char *       url;
 		int          i;
 		char         msgbuf[16];
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l.id != 0);
+		So(nng_listener_id(l) > 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d.id != 0);
+		So(nng_dialer_id(d) > 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -367,7 +367,7 @@ trantest_send_recv_multi(trantest *tt)
 			So(nng_msg_len(recv) == strlen(msgbuf) + 1);
 			So(strcmp(nng_msg_body(recv), msgbuf) == 0);
 			p = nng_msg_get_pipe(recv);
-			So(p.id != 0);
+			So(nng_pipe_id(p) > 0);
 			So(nng_pipe_getopt_string(p, NNG_OPT_URL, &url) == 0);
 			So(strcmp(url, tt->addr) == 0);
 			nng_strfree(url);
@@ -380,16 +380,16 @@ void
 trantest_check_properties(trantest *tt, trantest_proptest_t f)
 {
 	Convey("Properties test", {
-		nng_listener l;
-		nng_dialer   d;
+		nng_listener l = NNG_LISTENER_INITIALIZER;
+		nng_dialer   d = NNG_DIALER_INITIALIZER;
 		nng_msg *    send;
 		nng_msg *    recv;
 		int          rv;
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l.id != 0);
+		So(nng_listener_id(l) > 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d.id != 0);
+		So(nng_dialer_id(d) > 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
@@ -415,8 +415,8 @@ void
 trantest_send_recv_large(trantest *tt)
 {
 	Convey("Send and recv large data", {
-		nng_listener l;
-		nng_dialer   d;
+		nng_listener l = NNG_LISTENER_INITIALIZER;
+		nng_dialer   d = NNG_DIALER_INITIALIZER;
 		nng_msg *    send;
 		nng_msg *    recv;
 		char *       data;
@@ -430,9 +430,9 @@ trantest_send_recv_large(trantest *tt)
 		}
 
 		So(trantest_listen(tt, &l) == 0);
-		So(l.id != 0);
+		So(nng_listener_id(l) > 0);
 		So(trantest_dial(tt, &d) == 0);
-		So(d.id != 0);
+		So(nng_dialer_id(d) > 0);
 
 		nng_msleep(200); // listener may be behind slightly
 
diff --git a/tests/ws.c b/tests/ws.c
index b58ac40f..753f6be9 100644
--- a/tests/ws.c
+++ b/tests/ws.c
@@ -32,7 +32,7 @@ check_props_v4(nng_msg *msg)
 	size_t       len;
 
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 
 	So(nng_pipe_getopt_sockaddr(p, NNG_OPT_LOCADDR, &la) == 0);
 	So(la.s_family == NNG_AF_INET);
diff --git a/tests/wss.c b/tests/wss.c
index 333af56c..fac33398 100644
--- a/tests/wss.c
+++ b/tests/wss.c
@@ -141,7 +141,7 @@ check_props(nng_msg *msg)
 	size_t       len;
 
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 
 	z = sizeof(nng_sockaddr);
 	So(nng_pipe_getopt(p, NNG_OPT_LOCADDR, &la, &z) == 0);
diff --git a/tests/wssfile.c b/tests/wssfile.c
index 6b1d1a7b..9117c277 100644
--- a/tests/wssfile.c
+++ b/tests/wssfile.c
@@ -142,7 +142,7 @@ check_props(nng_msg *msg)
 	size_t       len;
 
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 
 	// Typed
 	z = sizeof(nng_sockaddr);
@@ -349,7 +349,7 @@ TestMain("WebSocket Secure (TLS) Transport (file based)", {
 		So(nng_msg_len(msg) == 6);
 		So(strcmp(nng_msg_body(msg), "hello") == 0);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt_bool(p, NNG_OPT_TLS_VERIFIED, &b) == 0);
 		So(b == false);
 		nng_msg_free(msg);
@@ -391,7 +391,7 @@ TestMain("WebSocket Secure (TLS) Transport (file based)", {
 		So(nng_msg_len(msg) == 6);
 		So(strcmp(nng_msg_body(msg), "hello") == 0);
 		p = nng_msg_get_pipe(msg);
-		So(p.id > 0);
+		So(nng_pipe_id(p) > 0);
 		So(nng_pipe_getopt_bool(p, NNG_OPT_TLS_VERIFIED, &b) == 0);
 		So(b == true);
 		nng_msg_free(msg);
diff --git a/tests/zt.c b/tests/zt.c
index d178f334..237cc01a 100644
--- a/tests/zt.c
+++ b/tests/zt.c
@@ -44,7 +44,7 @@ check_props(nng_msg *msg)
 {
 	nng_pipe p;
 	p = nng_msg_get_pipe(msg);
-	So(p.id > 0);
+	So(nng_pipe_id(p) > 0);
 
 	// Check local address.
 	Convey("Local address property works", {