fixes #1536 nng_sendmsg and nng_recvmsg could be faster

fixes #1535 Desire nng_ctx_sendmsg and nng_ctx_recvmsg

5 files changed, 156 insertions, 3 deletions

diff --git a/docs/man/libnng.3.adoc b/docs/man/libnng.3.adoc
index 712bf0fb..7475cdca 100644
--- a/docs/man/libnng.3.adoc
+++ b/docs/man/libnng.3.adoc
@@ -1,6 +1,6 @@
 = libnng(3)
 //
-// Copyright 2020 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
 // Copyright 2018 Capitar IT Group BV <info@capitar.com>
 // Copyright 2019 Devolutions <info@devolutions.net>
 // Copyright 2020 Dirac Research <robert.bielik@dirac.com>
@@ -231,7 +231,10 @@ concurrent applications.
 |xref:nng_ctx_id.3.adoc[nng_ctx_id()]|get numeric context identifier
 |xref:nng_ctx_open.3.adoc[nng_ctx_open()]|create context
 |xref:nng_ctx_recv.3.adoc[nng_ctx_recv()]|receive message using context asynchronously
+|xref:nng_ctx_recvmsg.3.adoc[nng_ctx_recvmsg()]|receive a message using context
 |xref:nng_ctx_send.3.adoc[nng_ctx_send()]|send message using context asynchronously
+|xref:nng_ctx_sendmsg.3.adoc[nng_ctx_sendmsg()]|send a message using context
+
 |xref:nng_ctx_set.3.adoc[nng_ctx_set()]|set context option
 |xref:nng_ctx_setopt.3.adoc[nng_ctx_setopt()]|set context option
 |===
diff --git a/docs/man/nng_ctx.5.adoc b/docs/man/nng_ctx.5.adoc
index cc859c48..c8ab62cd 100644
--- a/docs/man/nng_ctx.5.adoc
+++ b/docs/man/nng_ctx.5.adoc
@@ -165,7 +165,9 @@ xref:nng_ctx_open.3.adoc[nng_ctx_open(3)],
 xref:nng_ctx_get.3.adoc[nng_ctx_get(3)],
 xref:nng_ctx_id.3.adoc[nng_ctx_id(3)],
 xref:nng_ctx_recv.3.adoc[nng_ctx_recv(3)],
+xref:nng_ctx_recvmsg.3.adoc[nng_ctx_recvmsg(3)],
 xref:nng_ctx_send.3.adoc[nng_ctx_send(3)],
+xref:nng_ctx_sendmsg.3.adoc[nng_ctx_sendmsg(3)],
 xref:nng_ctx_set.3.adoc[nng_ctx_set(3)],
 xref:nng_dialer.5.adoc[nng_dialer(5)],
 xref:nng_listener.5.adoc[nng_listener(5)],
diff --git a/docs/man/nng_ctx_recvmsg.3.adoc b/docs/man/nng_ctx_recvmsg.3.adoc
new file mode 100644
index 00000000..9651c34c
--- /dev/null
+++ b/docs/man/nng_ctx_recvmsg.3.adoc
@@ -0,0 +1,63 @@
+= nng_ctx_recvmsg(3)
+//
+// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
+//
+// 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_recvmsg - receive message using socket
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_ctx_recvmsg(nng_ctx ctx, nng_msg **msgp, int flags);
+----
+
+== DESCRIPTION
+
+The `nng_ctx_recvmsg()` receives a message on context _ctx_, storing the
+received message at the location pointed to by _msgp_.
+
+The _flags_ may contain the following value:
+
+`NNG_FLAG_NONBLOCK`::
+  The function returns immediately, even if no message is available.
+  Without this flag, the function will wait until a message is receivable
+  on the context _ctx_, or any configured timer expires.
+
+NOTE: The semantics of what receiving a message means vary from protocol to
+protocol, so examination of the protocol documentation is encouraged.
+
+== RETURN VALUES
+
+This function returns 0 on success, and non-zero otherwise.
+
+== ERRORS
+
+[horizontal]
+`NNG_EAGAIN`:: The operation would block, but `NNG_FLAG_NONBLOCK` was specified.
+`NNG_ECLOSED`:: The context or socket is not open.
+`NNG_EINVAL`:: An invalid set of _flags_ was specified.
+`NNG_ENOMEM`:: Insufficient memory is available.
+`NNG_ENOTSUP`:: The protocol does not support receiving.
+`NNG_ESTATE`:: The context cannot receive data in this state.
+`NNG_ETIMEDOUT`:: The operation timed out.
+
+== SEE ALSO
+
+[.text-left]
+xref:nng_msg_free.3.adoc[nng_msg_free(3)],
+xref:nng_ctx_open.3.adoc[nng_ctx_open(3)],
+xref:nng_ctx_recv.3.adoc[nng_ctx_recv(3)],
+xref:nng_ctx_sendmsg.3.adoc[nng_ctx_sendmsg(3)],
+xref:nng_strerror.3.adoc[nng_strerror(3)],
+xref:nng_ctx.5.adoc[nng_ctx(5)],
+xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_ctx_sendmsg.3.adoc b/docs/man/nng_ctx_sendmsg.3.adoc
new file mode 100644
index 00000000..8e2c97f4
--- /dev/null
+++ b/docs/man/nng_ctx_sendmsg.3.adoc
@@ -0,0 +1,84 @@
+= nng_ctx_sendmsg(3)
+//
+// Copyright 2021 Staysail Systems, Inc. <info@staysail.tech>
+//
+// 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_sendmsg - send message using context
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+
+int nng_ctx_sendmsg(nng_ctx c, nng_msg *msg, int flags);
+----
+
+== DESCRIPTION
+
+The `nng_ctx_sendmsg()` sends message _msg_ using the context _ctx_.
+
+If the function returns zero, indicating it has accepted the message for
+delivery, then the _msg_ is owned by the socket _s_, and the caller
+must not make any further use of it.
+The socket will free the message when it is finished.
+
+If the function returns non-zero, then it is the caller's responsibility
+to dispose of the _msg_, which may include freeing it, sending it to
+another socket, or simply trying again later.
+
+NOTE: The semantics of what sending a message means vary from protocol to
+protocol, so examination of the protocol documentation is encouraged.
+
+The _flags_ may contain the following value:
+
+`NNG_FLAG_NONBLOCK`::
+    The function returns immediately, regardless of whether
+    the context is able to accept the data or not.
+    If the context is unable to accept the data (such as if backpressure exists
+    because the peers are consuming messages too slowly, or no peer is present),
+    then the function will return with `NNG_EAGAIN`.
+    If this flag is not specified, then the function will block if such a
+    condition exists.
+
+
+NOTE: Regardless of the presence or absence of `NNG_FLAG_NONBLOCK`, there may
+be queues between the sender and the receiver.
+Furthermore, there is no guarantee that the message has actually been delivered.
+Finally, with some protocols, the semantic is implicitly `NNG_FLAG_NONBLOCK`.
+
+== RETURN VALUES
+
+This function returns 0 on success, and non-zero otherwise.
+
+== ERRORS
+
+[horizontal]
+`NNG_EAGAIN`:: The operation would block, but `NNG_FLAG_NONBLOCK` was specified.
+`NNG_ECLOSED`:: The context or socket is not open.
+`NNG_EINVAL`:: An invalid set of _flags_ was specified.
+`NNG_EMSGSIZE`:: The value of _size_ is too large.
+`NNG_ENOMEM`:: Insufficient memory is available.
+`NNG_ENOTSUP`:: The protocol does not support sending.
+`NNG_ESTATE`:: The context cannot send data in this state.
+`NNG_ETIMEDOUT`:: The operation timed out.
+
+== SEE ALSO
+
+[.text-left]
+xref:nng_msg_alloc.3.adoc[nng_msg_alloc(3)],
+xref:nng_ctx_open.3.adoc[nng_ctx_open(3)],
+xref:nng_ctx_recvmsg.3.adoc[nng_ctx_recvmsg(3)],
+xref:nng_ctx_send.3.adoc[nng_ctx_send(3)],
+xref:nng_sendmsg.3.adoc[nng_sendmsg(3)],
+xref:nng_strerror.3.adoc[nng_strerror(3)],
+xref:nng_msg.5.adoc[nng_msg(5)],
+xref:nng_ctx.5.adoc[nng_ctx(5)],
+xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_recvmsg.3.adoc b/docs/man/nng_recvmsg.3.adoc
index 6f1fcea9..c502d650 100644
--- a/docs/man/nng_recvmsg.3.adoc
+++ b/docs/man/nng_recvmsg.3.adoc
@@ -1,6 +1,6 @@
 = nng_recvmsg(3)
 //
-// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
+// Copyright 2021 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
@@ -11,7 +11,7 @@
 
 == NAME
 
-nng_recvmsg - recv message
+nng_recvmsg - receive a message
 
 == SYNOPSIS
 
@@ -67,4 +67,5 @@ xref:nng_msg_free.3.adoc[nng_msg_free(3)],
 xref:nng_recv.3.adoc[nng_recv(3)],
 xref:nng_sendmsg.3.adoc[nng_sendmsg(3)],
 xref:nng_strerror.3.adoc[nng_strerror(3)],
+xref:nng_socket.5.adoc[nng_socket(5)],
 xref:nng.7.adoc[nng(7)]