fixes #1536 nng_sendmsg and nng_recvmsg could be faster

fixes #1535 Desire nng_ctx_sendmsg and nng_ctx_recvmsg

1 files changed, 63 insertions, 0 deletions

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)]