Add documentation for supplemental functions.

This includes platform portability stuff like mutexes and threads,
etc.  While here we fixed a problem with nng_opts_parse and we
addressed the type of the platform API.

1 files changed, 44 insertions, 0 deletions

diff --git a/docs/man/nng_random.3supp.adoc b/docs/man/nng_random.3supp.adoc
new file mode 100644
index 00000000..9003fea8
--- /dev/null
+++ b/docs/man/nng_random.3supp.adoc
@@ -0,0 +1,44 @@
+= nng_random(3supp)
+//
+// 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_random - get random number
+
+== SYNOPSIS
+
+[source, c]
+----
+#include <nng/nng.h>
+#include <nng/supplemental/util/platform.h>
+
+uint32_t nng_random(void);
+----
+
+== DESCRIPTION
+
+The `nng_random()` returns a random number.
+The value returned is suitable for use with cryptographic functions such as
+key generation.
+The value is obtained using platform specific cryptographically strong random
+number facilities when available.
+
+== RETURN VALUES
+
+Random number.
+
+== ERRORS
+
+None.
+
+== SEE ALSO
+
+<<nng.7#,nng(7)>>