I/O provider pages.

12 files changed, 167 insertions, 317 deletions

diff --git a/docs/man/nng_aio_begin.3.adoc b/docs/man/nng_aio_begin.3.adoc
deleted file mode 100644
index 30a73648..00000000
--- a/docs/man/nng_aio_begin.3.adoc
+++ /dev/null
@@ -1,64 +0,0 @@
-= nng_aio_begin(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_aio_begin - begin asynchronous I/O operation
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-bool nng_aio_begin(nng_aio *aio);
-----
-
-== DESCRIPTION
-
-The `nng_aio_begin()` function is called by the I/O provider to indicate that
-it is going to process the operation.
-
-The function may return `false`, indicating that the _aio_ has been closed
-by the caller asynchronously.
-In this case the provider should abandon the operation and do nothing else.
-
-This operation should be called at the start of any I/O operation, and must
-be called not more than once for a given I/O operation on a given _aio_.
-
-Once this function is called, if `true` is returned, then the provider MUST
-guarantee that xref:nng_aio_finish.3.adoc[`nng_aio_finish()`] is called for the _aio_
-exactly once, when the operation is complete or canceled.
-
-NOTE: This function is only for I/O providers (those actually performing
-the operation such as HTTP handler functions or transport providers); ordinary
-users of the _aio_ should not call this function.
-
-== RETURN VALUES
-
-[horizontal]
-`true`:: The operation has been started.
-`false`:: The operation cannot be started.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
-xref:nng_aio_cancel.3.adoc[nng_aio_cancel(3)],
-xref:nng_aio_defer.3.adoc[nng_aio_defer(3)],
-xref:nng_aio_finish.3.adoc[nng_aio_finish(3)],
-xref:nng_aio_result.3.adoc[nng_aio_result(3)],
-xref:nng_aio.5.adoc[nng_aio(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_aio_defer.3.adoc b/docs/man/nng_aio_defer.3.adoc
deleted file mode 100644
index 5664a6df..00000000
--- a/docs/man/nng_aio_defer.3.adoc
+++ /dev/null
@@ -1,78 +0,0 @@
-= nng_aio_defer(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_aio_defer - defer asynchronous I/O operation
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-typedef void (*nng_aio_cancelfn)(nng_aio *aio, void *arg, int err);
-
-void nng_aio_defer(nng_aio *aio, nng_aio_cancelfn fn, void *arg);
-----
-
-== DESCRIPTION
-
-The `nng_aio_defer()` function marks operation associated with _aio_ as
-being deferred for asynchronous completion, and also registers a cancellation
-function _fn_ and associated argument _arg_, thereby
-permitting the operation to be canceled.
-
-If the _aio_ is being canceled, the cancellation routine _fn_ will be called
-with the _aio_, the _arg_ specified by `nng_aio_defer()`, and an error
-value in _err_, which is the reason that the operation is being canceled.
-
-The operation may not be cancelable; for example it may have already been
-completed, or be in a state where it is no longer possible to unschedule it.
-In this case, the _cancelfn_ should just return without making any changes.
-
-If the cancellation routine successfully canceled the operation, it should
-ensure that xref:nng_aio_finish.3.adoc[`nng_aio_finish()`] is called, with the
-error code specified by _err_.
-
-IMPORTANT: It is mandatory that I/O providers call
-xref:nng_aio_finish.3.adoc[`nng_aio_finish()`]
-*EXACTLY ONCE* when they are finished with the operation.
-
-NOTE: This function is only for I/O providers (those actually performing
-the operation such as HTTP handler functions or transport providers); ordinary
-users of the _aio_ should not call this function.
-
-NOTE: Care must be taken to ensure that cancellation and completion of
-the routine are multi-thread safe; this will usually involve the use
-of locks or other synchronization primitives.
-
-TIP: For operations that complete synchronously, without any need to be
-deferred, the provider should not bother to call `nng_aio_defer()`,
-although it is harmless if it does.
-
-== RETURN VALUES
-
-None.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
-xref:nng_aio_cancel.3.adoc[nng_aio_cancel(3)],
-xref:nng_aio_finish.3.adoc[nng_aio_finish(3)],
-xref:nng_aio_result.3.adoc[nng_aio_result(3)],
-xref:nng_aio.5.adoc[nng_aio(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_aio_finish.3.adoc b/docs/man/nng_aio_finish.3.adoc
deleted file mode 100644
index 91ad188e..00000000
--- a/docs/man/nng_aio_finish.3.adoc
+++ /dev/null
@@ -1,60 +0,0 @@
-= nng_aio_finish(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_aio_finish - finish asynchronous I/O operation
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-void nng_aio_finish(nng_aio *aio, int err);
-----
-
-== DESCRIPTION
-
-The `nng_aio_finish()` function marks operation associated with _aio_ as
-complete, with the status _err_.
-This will be the result returned by
-xref:nng_aio_result.3.adoc[`nng_aio_result()`].
-
-This function causes the callback associated with the _aio_ to called.
-
-IMPORTANT: It is mandatory that operation providers call this function
-*exactly once* when they are finished with the operation.
-After calling this function they *must not* perform any further accesses
-to the _aio_.
-
-NOTE: This function is only for I/O providers (those actually performing
-the operation such as HTTP handler functions or transport providers); ordinary
-users of the _aio_ should not have any need for this function.
-
-== RETURN VALUES
-
-None.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
-xref:nng_aio_begin.3.adoc[nng_aio_begin(3)],
-xref:nng_aio_cancel.3.adoc[nng_aio_cancel(3)],
-xref:nng_aio_defer.3.adoc[nng_aio_defer(3)],
-xref:nng_aio_result.3.adoc[nng_aio_result(3)],
-xref:nng_aio.5.adoc[nng_aio(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_aio_get_input.3.adoc b/docs/man/nng_aio_get_input.3.adoc
deleted file mode 100644
index 204ec435..00000000
--- a/docs/man/nng_aio_get_input.3.adoc
+++ /dev/null
@@ -1,53 +0,0 @@
-= nng_aio_get_input(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_aio_get_input - return input parameter
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-void *nng_aio_get_input(nng_aio *aio, unsigned int index);
-----
-
-== DESCRIPTION
-
-The `nng_aio_get_input()` function returns the value of the input parameter
-previously set at _index_ on _aio_ with the
-xref:nng_aio_set_input.3.adoc[`nng_aio_set_input()`] function.
-
-The valid values of _index_ range from zero (0) to three (3), as no operation
-currently defined can accept more than four parameters.
-(This limit could increase in the future.)
-If the index supplied is outside of this range,
-or of the input parameter was not previously set, then `NULL` is returned.
-
-== RETURN VALUES
-
-Value previously set, or `NULL`.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
-xref:nng_aio_get_output.3.adoc[nng_aio_get_output(3)],
-xref:nng_aio_set_input.3.adoc[nng_aio_set_input(3)],
-xref:nng_aio_result.3.adoc[nng_aio_result(3)],
-xref:nng_aio.5.adoc[nng_aio(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/man/nng_aio_set_output.3.adoc b/docs/man/nng_aio_set_output.3.adoc
deleted file mode 100644
index 67f8ac66..00000000
--- a/docs/man/nng_aio_set_output.3.adoc
+++ /dev/null
@@ -1,60 +0,0 @@
-= nng_aio_set_output(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_aio_set_output - set output result
-
-== SYNOPSIS
-
-[source, c]
-----
-#include <nng/nng.h>
-
-void nng_aio_set_output(nng_aio *aio, unsigned int index, void *result);
-----
-
-== DESCRIPTION
-
-The `nng_aio_set_output()` function sets the output result at _index_
-to _result_ for the asynchronous operation associated with _aio_.
-
-The type and semantics of output results are determined by specific
-operations; the operation must supply appropriate output results when
-the operation completes successfully.
-
-The valid values of _index_ range from zero (0) to three (3), as no operation
-currently defined can return more than four results.
-(This limit could increase in the future.)
-
-NOTE:  Note that attempts to set results with an _index_ greater than
-three (3) will be ignored.
-
-An output result set with this function may be retrieved later with
-the xref:nng_aio_get_output.3.adoc[`nng_aio_get_output()`] function.
-
-== RETURN VALUES
-
-None.
-
-== ERRORS
-
-None.
-
-== SEE ALSO
-
-[.text-left]
-xref:nng_aio_alloc.3.adoc[nng_aio_alloc(3)],
-xref:nng_aio_finish.3.adoc[nng_aio_finish(3)],
-xref:nng_aio_get_output.3.adoc[nng_aio_get_output(3)],
-xref:nng_aio_result.3.adoc[nng_aio_result(3)],
-xref:nng_aio.5.adoc[nng_aio(5)],
-xref:nng.7.adoc[nng(7)]
diff --git a/docs/ref/aio/nng_aio_set_iov.adoc b/docs/ref/aio/nng_aio_set_iov.adoc
index b4938fcc..2db39ad8 100644
--- a/docs/ref/aio/nng_aio_set_iov.adoc
+++ b/docs/ref/aio/nng_aio_set_iov.adoc
@@ -43,7 +43,6 @@ This function returns 0 on success, and non-zero otherwise.
 
 ### See Also
 
-[.text-left]
 xref:nng_aio_count.adoc[nng_aio_count],
 xref:nng_aio_result.adoc[nng_aio_result],
 xref:nng_iov.5.adoc[nng_iov]
diff --git a/docs/ref/aio/nng_aio_set_msg.adoc b/docs/ref/aio/nng_aio_set_msg.adoc
index 7dc06841..f808c69f 100644
--- a/docs/ref/aio/nng_aio_set_msg.adoc
+++ b/docs/ref/aio/nng_aio_set_msg.adoc
@@ -17,7 +17,6 @@ The `nng_aio_set_msg` function sets the message that will be used for an asynchr
 
 ### See Also
 
-[.text-left]
 xref:nng_aio_get_msg.adoc[nng_aio_get_msg],
 xref:../sock/nng_send_aio.adoc[nng_send_aio],
 xref:nng_msg.adoc[nng_msg]
diff --git a/docs/ref/iop/nng_aio_begin.adoc b/docs/ref/iop/nng_aio_begin.adoc
new file mode 100644
index 00000000..a634063c
--- /dev/null
+++ b/docs/ref/iop/nng_aio_begin.adoc
@@ -0,0 +1,37 @@
+## nng_aio_begin
+
+Begin asynchronous I/O operation.
+
+### Synopsis
+
+```c
+#include <nng/nng.h>
+
+bool nng_aio_begin(nng_aio *aio);
+```
+
+### Description
+
+The `nng_aio_begin` function is called by the I/O provider to indicate that it is going to process the operation.
+
+The function may return `false`, indicating that the _aio_ has been closed by the caller asynchronously.
+In this case the provider should abandon the operation and do nothing else.
+
+This operation should be called at the start of any I/O operation, and must be called not more than once for a given I/O operation on a given _aio_.
+
+Once this function is called, if `true` is returned, then the provider must guarantee that xref:nng_aio_finish.adoc[`nng_aio_finish`] is called for the _aio_ exactly once, when the operation is complete or canceled.
+
+TIP: This function is only for I/O providers (those actually performing
+the operation such as HTTP handler functions or transport providers); ordinary
+users of the _aio_ should not call this function.
+
+### Return Values
+
+[horizontal]
+`true`:: The operation has been started.
+`false`:: The operation cannot be started.
+
+### See Also
+
+xref:nng_aio_defer.adoc[nng_aio_defer],
+xref:nng_aio_finish.adoc[nng_aio_finish]
diff --git a/docs/ref/iop/nng_aio_defer.adoc b/docs/ref/iop/nng_aio_defer.adoc
new file mode 100644
index 00000000..7dc3918f
--- /dev/null
+++ b/docs/ref/iop/nng_aio_defer.adoc
@@ -0,0 +1,42 @@
+## nng_aio_defer
+
+Defer asynchronous I/O operation.
+
+### Synopsis
+
+```c
+#include <nng/nng.h>
+
+typedef void (*nng_aio_cancelfn)(nng_aio *aio, void *arg, int err);
+
+void nng_aio_defer(nng_aio *aio, nng_aio_cancelfn fn, void *arg);
+```
+
+### Description
+
+The `nng_aio_defer` function marks the operation associated with _aio_ as deferred for asynchronous completion, registering a cancellation function _fn_ and associated argument _arg_.
+This permits the operation to be canceled.
+
+If the _aio_ is canceled, the cancellation routine _fn_ will be called with the _aio_, the _arg_ specified by `nng_aio_defer`, and an error value in _err_, which is the reason for cancellation.
+
+The operation may not be cancelable; for example it may have already been completed, or be in a state where it is no longer possible to unschedule it.
+In this case, the _cancelfn_ should just return without making any changes.
+
+If the cancellation routine successfully canceled the operation, it should ensure that xref:nng_aio_finish.adoc[`nng_aio_finish`] is called, with the error code specified by _err_.
+
+IMPORTANT: It is mandatory that I/O providers call xref:nng_aio_finish.adoc[`nng_aio_finish`] *exactly once* when they are finished with the operation.
+
+IMPORTANT: Care must be taken to ensure that cancellation and completion of the routine are thread-safe.
+This will usually involve the use of locks or other synchronization primitives.
+
+TIP: This function is only for I/O providers (those actually performing the operation such as HTTP handler functions or transport providers).
+Ordinary users of the _aio_ should not call this function.
+
+
+TIP: When completing an operation synchronously, calling `nng_aio_defer` is unnecessary.
+
+### See Also
+
+xref:../aio/nng_aio_cancel.adoc[nng_aio_cancel],
+xref:nng_aio_finish.adoc[nng_aio_finish],
+xref:../aio/nng_aio_result.adoc[nng_aio_result]
diff --git a/docs/ref/iop/nng_aio_finish.adoc b/docs/ref/iop/nng_aio_finish.adoc
new file mode 100644
index 00000000..77622fd5
--- /dev/null
+++ b/docs/ref/iop/nng_aio_finish.adoc
@@ -0,0 +1,31 @@
+## nng_aio_finish
+
+Finish asynchronous I/O operation.
+
+### Synopsis
+
+```c
+#include <nng/nng.h>
+
+void nng_aio_finish(nng_aio *aio, int err);
+```
+
+### Description
+
+The `nng_aio_finish` function marks operation associated with _aio_ as complete, with the status _err_.
+This will be the result returned by xref:nng_aio_result.adoc[`nng_aio_result`].
+
+This function causes the callback associated with the _aio_ to called.
+
+IMPORTANT: It is mandatory that operation providers call this function *exactly once* when they are finished with the operation.
+After calling this function they *must not* perform any further accesses to the _aio_.
+
+TIP: This function is only for I/O providers (those actually performing the operation such as HTTP handler functions or transport providers).
+Ordinary users of the _aio_ should not have any need for this function.
+
+### See Also
+
+xref:nng_aio_begin.adoc[nng_aio_begin],
+xref:../aio/nng_aio_cancel.adoc[nng_aio_cancel],
+xref:nng_aio_defer.adoc[nng_aio_defer],
+xref:../aio/nng_aio_result.adoc[nng_aio_result]
diff --git a/docs/ref/iop/nng_aio_get_input.adoc b/docs/ref/iop/nng_aio_get_input.adoc
new file mode 100644
index 00000000..83d1d86d
--- /dev/null
+++ b/docs/ref/iop/nng_aio_get_input.adoc
@@ -0,0 +1,27 @@
+## nng_aio_get_input
+
+Return input parameter.
+
+### Synopsis
+
+```c
+#include <nng/nng.h>
+
+void *nng_aio_get_input(nng_aio *aio, unsigned int index);
+```
+
+### Description
+
+The `nng_aio_get_input` function returns the value of the input parameter previously set at _index_ on _aio_ with the xref:../aio/nng_aio_set_input.adoc[`nng_aio_set_input`] function.
+
+The valid values of _index_ range from zero (0) to three (3), as no operation currently defined can accept more than four parameters.
+If the index supplied is outside of this range, or of the input parameter was not previously set, then `NULL` is returned.
+
+### Return Values
+
+Value previously set, or `NULL`.
+
+### See Also
+
+xref:../aio/nng_aio_set_input.adoc[nng_aio_set_input],
+xref:nng_aio_set_output.adoc[nng_aio_set_output]
diff --git a/docs/ref/iop/nng_aio_set_output.adoc b/docs/ref/iop/nng_aio_set_output.adoc
new file mode 100644
index 00000000..fc9c90a2
--- /dev/null
+++ b/docs/ref/iop/nng_aio_set_output.adoc
@@ -0,0 +1,30 @@
+## nng_aio_set_output
+
+Set output result.
+
+### Synopsis
+
+```c
+#include <nng/nng.h>
+
+void nng_aio_set_output(nng_aio *aio, unsigned int index, void *result);
+```
+
+### Description
+
+The `nng_aio_set_output` function sets the output result at _index_ to _result_ for the asynchronous operation associated with _aio_.
+
+The type and semantics of output results are determined by specific operations.
+The operation must supply appropriate output results when the operation completes successfully.
+
+The valid values of _index_ range from zero (0) to three (3), as no operation currently defined can return more than four results.
+Attempts to set results with an _index_ greater than three (3) will be ignored.
+
+An output result set with this function may be retrieved later with
+the xref:nng_aio_get_output.adoc[`nng_aio_get_output`] function.
+
+
+### See Also
+
+xref:nng_aio_get_input.adoc[nng_aio_get_inpput],
+xref:../aio/nng_aio_get_output.adoc[nng_aio_get_output]