Merge branch 'doc-updates' of git.lucina.net:libxsv1.0.0

11 files changed, 284 insertions, 298 deletions

diff --git a/INSTALL b/INSTALL
index d3c5b40..09e525a 100644
--- a/INSTALL
+++ b/INSTALL
@@ -1,237 +1,85 @@
 Installation Instructions
-*************************
+-------------------------
 
-Copyright (C) 1994, 1995, 1996, 1999, 2000, 2001, 2002, 2004, 2005,
-2006, 2007 Free Software Foundation, Inc.
 
-This file is free documentation; the Free Software Foundation gives
-unlimited permission to copy, distribute and modify it.
-
-Basic Installation
-==================
+In Brief
+~~~~~~~~
 
-Briefly, the shell commands `./configure; make; make install' should
-configure, build, and install this package.  The following
-more-detailed instructions are generic; see the `README' file for
-instructions specific to this package.
-
-   The `configure' shell script attempts to guess correct values for
-various system-dependent variables used during compilation.  It uses
-those values to create a `Makefile' in each directory of the package.
-It may also create one or more `.h' files containing system-dependent
-definitions.  Finally, it creates a shell script `config.status' that
-you can run in the future to recreate the current configuration, and a
-file `config.log' containing compiler output (useful mainly for
-debugging `configure').
-
-   It can also use an optional file (typically called `config.cache'
-and enabled with `--cache-file=config.cache' or simply `-C') that saves
-the results of its tests to speed up reconfiguring.  Caching is
-disabled by default to prevent problems with accidental use of stale
-cache files.
-
-   If you need to do unusual things to compile the package, please try
-to figure out how `configure' could check whether to do them, and mail
-diffs or instructions to the address given in the `README' so they can
-be considered for the next release.  If you are using the cache, and at
-some point `config.cache' contains results you don't want to keep, you
-may remove or edit it.
-
-   The file `configure.ac' (or `configure.in') is used to create
-`configure' by a program called `autoconf'.  You need `configure.ac' if
-you want to change it or regenerate `configure' using a newer version
-of `autoconf'.
-
-The simplest way to compile this package is:
-
-  1. `cd' to the directory containing the package's source code and type
-     `./configure' to configure the package for your system.
-
-     Running `configure' might take a while.  While running, it prints
-     some messages telling which features it is checking for.
-
-  2. Type `make' to compile the package.
-
-  3. Optionally, type `make check' to run any self-tests that come with
-     the package.
-
-  4. Type `make install' to install the programs and any data files and
-     documentation.
-
-  5. You can remove the program binaries and object files from the
-     source code directory by typing `make clean'.  To also remove the
-     files that `configure' created (so you can compile the package for
-     a different kind of computer), type `make distclean'.  There is
-     also a `make maintainer-clean' target, but that is intended mainly
-     for the package's developers.  If you use it, you may have to get
-     all sorts of other programs in order to regenerate files that came
-     with the distribution.
-
-  6. Often, you can also type `make uninstall' to remove the installed
-     files again.
-
-Compilers and Options
-=====================
-
-Some systems require unusual options for compilation or linking that the
-`configure' script does not know about.  Run `./configure --help' for
-details on some of the pertinent environment variables.
-
-   You can give `configure' initial values for configuration parameters
-by setting variables in the command line or in the environment.  Here
-is an example:
-
-     ./configure CC=c99 CFLAGS=-g LIBS=-lposix
-
-   *Note Defining Variables::, for more details.
-
-Compiling For Multiple Architectures
-====================================
-
-You can compile the package for more than one kind of computer at the
-same time, by placing the object files for each architecture in their
-own directory.  To do this, you can use GNU `make'.  `cd' to the
-directory where you want the object files and executables to go and run
-the `configure' script.  `configure' automatically checks for the
-source code in the directory that `configure' is in and in `..'.
-
-   With a non-GNU `make', it is safer to compile the package for one
-architecture at a time in the source code directory.  After you have
-installed the package for one architecture, use `make distclean' before
-reconfiguring for another architecture.
-
-Installation Names
-==================
-
-By default, `make install' installs the package's commands under
-`/usr/local/bin', include files under `/usr/local/include', etc.  You
-can specify an installation prefix other than `/usr/local' by giving
-`configure' the option `--prefix=PREFIX'.
-
-   You can specify separate installation prefixes for
-architecture-specific files and architecture-independent files.  If you
-pass the option `--exec-prefix=PREFIX' to `configure', the package uses
-PREFIX as the prefix for installing programs and libraries.
-Documentation and other data files still use the regular prefix.
-
-   In addition, if you use an unusual directory layout you can give
-options like `--bindir=DIR' to specify different values for particular
-kinds of files.  Run `configure --help' for a list of the directories
-you can set and what kinds of files go in them.
-
-   If the package supports it, you can cause programs to be installed
-with an extra prefix or suffix on their names by giving `configure' the
-option `--program-prefix=PREFIX' or `--program-suffix=SUFFIX'.
+The following instructions apply to building libxs from an official release
+downloaded from the Crossroads I/O website. For building directly from Git,
+see below.
 
-Optional Features
-=================
-
-Some packages pay attention to `--enable-FEATURE' options to
-`configure', where FEATURE indicates an optional part of the package.
-They may also pay attention to `--with-PACKAGE' options, where PACKAGE
-is something like `gnu-as' or `x' (for the X Window System).  The
-`README' should mention any `--enable-' and `--with-' options that the
-package recognizes.
-
-   For packages that use the X Window System, `configure' can usually
-find the X include and library files automatically, but if it doesn't,
-you can use the `configure' options `--x-includes=DIR' and
-`--x-libraries=DIR' to specify their locations.
-
-Specifying the System Type
-==========================
-
-There may be some features `configure' cannot figure out automatically,
-but needs to determine by the type of machine the package will run on.
-Usually, assuming the package is built to be run on the _same_
-architectures, `configure' can figure that out, but if it prints a
-message saying it cannot guess the machine type, give it the
-`--build=TYPE' option.  TYPE can either be a short name for the system
-type, such as `sun4', or a canonical name which has the form:
+On POSIX platforms, libxs uses the standard autotools build system. To
+build and install the library, ensure your system has a C++ compiler
+installed, and proceed with the following steps:
 
-     CPU-COMPANY-SYSTEM
+1. Run `./configure`, then `make` to build the library.
+2. Optionally, run `make test` to run the built in test suite.
+3. Run `make install` as root.
+4. On Linux or other platforms which use ld.so for dynamic linking, run
+   `ldconfig` or equivalent as root to update your systems shared library
+   cache.
 
-where SYSTEM can have one of these forms:
+On Windows, solution files for Visual C++ 2010 are provided in the
+`builds/msvc/` subdirectory of the distribution.
 
-     OS KERNEL-OS
 
-   See the file `config.sub' for the possible values of each field.  If
-`config.sub' isn't included in this package, then this package doesn't
-need to know the machine type.
+Building from Git
+~~~~~~~~~~~~~~~~~
 
-   If you are _building_ compiler tools for cross-compiling, you should
-use the option `--target=TYPE' to select the type of system they will
-produce code for.
+If you are building libxs directly from the Git tree, on POSIX platforms
+you will need to generate the `configure` script. This requires that you
+have `autoconf` and `automake` installed on your system. To generate
+`configure`, run `./autogen.sh`.
 
-   If you want to _use_ a cross compiler, that generates code for a
-platform different from the build platform, you should specify the
-"host" platform (i.e., that on which the generated programs will
-eventually be run) with `--host=TYPE'.
+Note that documentation in UNIX 'man' and HTML formats will only be built
+and installed from a Git tree if you have the `asciidoc` package installed
+on your system.
 
-Sharing Defaults
-================
+Once you have generated `configure` you can follow the brief steps above.
 
-If you want to set default values for `configure' scripts to share, you
-can create a site shell script called `config.site' that gives default
-values for variables like `CC', `cache_file', and `prefix'.
-`configure' looks for `PREFIX/share/config.site' if it exists, then
-`PREFIX/etc/config.site' if it exists.  Or, you can set the
-`CONFIG_SITE' environment variable to the location of the site script.
-A warning: not all `configure' scripts look for a site script.
 
-Defining Variables
-==================
-
-Variables not defined in a site shell script can be set in the
-environment passed to `configure'.  However, some packages may run
-configure again during the build, and the customized values of these
-variables may be lost.  In order to avoid this problem, you should set
-them in the `configure' command line, using `VAR=value'.  For example:
-
-     ./configure CC=/usr/local2/bin/gcc
-
-causes the specified `gcc' to be used as the C compiler (unless it is
-overridden in the site shell script).
-
-Unfortunately, this technique does not work for `CONFIG_SHELL' due to
-an Autoconf bug.  Until the bug is fixed you can use this workaround:
+Optional Features
+~~~~~~~~~~~~~~~~~
 
-     CONFIG_SHELL=/bin/bash /bin/bash ./configure CONFIG_SHELL=/bin/bash
+libxs provides several optional features or extensions. These are enabled
+using options to `configure`, or special project files for Windows.
 
-`configure' Invocation
-======================
+Common optional features, and their options to `configure`:
 
-`configure' recognizes the following options to control how it operates.
+ZeroMQ Compatibility::
+   Specify `--enable-libzmq` to enable building and installation of the
+   drop-in `libzmq` compatibility library for ZeroMQ applications. Note
+   that this will *overwrite* any existing installation of `libzmq` on your
+   system. For further details refer to `doc/xs_zmq.html` or 'xs_zmq(7)'.
 
-`--help'
-`-h'
-     Print a summary of the options to `configure', and exit.
+PGM multicast support::
+   Enabled with `--with-pgm` (using the copy of OpenPGM bundled with libxs)
+   or `--with-system-pgm` (using your system installation of OpenPGM).
+   Refer to `doc/xs_pgm.html` or 'xs_pgm(7)' for details on usage.
 
-`--version'
-`-V'
-     Print the version of Autoconf used to generate the `configure'
-     script, and exit.
 
-`--cache-file=FILE'
-     Enable the cache: use and save the results of the tests in FILE,
-     traditionally `config.cache'.  FILE defaults to `/dev/null' to
-     disable caching.
+Other Common Options
+~~~~~~~~~~~~~~~~~~~~
 
-`--config-cache'
-`-C'
-     Alias for `--cache-file=config.cache'.
+Specifying the installation directory::
+   libxs is installed in `/usr/local` by default. To change this, specify
+   the `--prefix` option to `configure`.
 
-`--quiet'
-`--silent'
-`-q'
-     Do not print messages saying which checks are being made.  To
-     suppress all normal output, redirect it to `/dev/null' (any error
-     messages will still be shown).
+Selecting a poller implementation::
+   libxs will normally pick the correct poller to use on your platform. If
+   cross compiling, or building for an older system you may need to
+   override this using the `--with-poller` option.
 
-`--srcdir=DIR'
-     Look for the package's source code in directory DIR.  Usually
-     `configure' can determine that directory automatically.
+Disabling eventfd for older Linux::
+   If building libxs to run on an older Linux kernel you may need to
+   disable eventfd support. This can be done with the `--disable-eventfd`
+   option.
 
-`configure' also accepts some other, not widely useful, options.  Run
-`configure --help' for more details.
+Disabling building and installing documentation::
+   Specifying `--without-documentation` disables any (re-)building or
+   installation of the AsciiDoc-generated documentation. 
 
+Refer to `./configure --help` for a full list of supported options, and
+more information on settings affecting the build (e.g. cross compiling,
+choosing a particular compiler version, and so on).
diff --git a/README b/README
index 72af2bd..1797849 100644
--- a/README
+++ b/README
@@ -1,28 +1,99 @@
 Welcome
 -------
 
-libxs is a library which extends the standard socket interfaces with features
-traditionally provided by specialised messaging middleware products. libxs
-sockets provide an abstraction of asynchronous message queues, multiple
-messaging patterns, message filtering (subscriptions), seamless access to
-multiple transport protocols and more.
+Crossroads I/O ("libxs") is a library for building scalable and high
+performance distributed applications. It fits between classic BSD sockets,
+JMS/AMQP-style message queues, and enterprise message-oriented middleware.
 
+Crossroads I/O extends the standard socket interfaces with features
+traditionally provided by specialised messaging middleware products,
+providing an abstraction of asynchronous message queues, multiple messaging
+patterns, message filtering (subscriptions), seamless access to multiple
+transport protocols, and more.
 
-Building and installation
+Crossroads I/O provides a native C API for applications. Support for many
+more languages is provided by the community through language bindings which
+can be found at the Crossroads website.
+
+
+Building and Installation
 -------------------------
 
-See the INSTALL file included with the distribution.
+The following instructions apply to building libxs from an official release
+downloaded from the Crossroads I/O website. For building directly from Git,
+refer to the `INSTALL` file included with the libxs distribution.
+
+On POSIX platforms, libxs uses the standard autotools build system. To
+build and install the library, ensure your system has a C++ compiler
+installed, and proceed with the following steps:
+
+1. Run `./configure`, then `make` to build the library.
+2. Optionally, run `make test` to run the built in test suite.
+3. Run `make install` as root.
+4. On Linux or other platforms which use ld.so for dynamic linking, run
+   `ldconfig` or equivalent as root to update your systems shared library
+   cache.
+
+On Windows, solution files for Visual C++ 2010 are provided in the
+`builds/msvc/` subdirectory of the distribution.
+
+Refer to the `INSTALL` file included with the libxs distribution for more
+detailed installation instructions.
+
+
+ZeroMQ Compatibility
+--------------------
+
+Crossroads I/O provides a drop-in 'libzmq' compatibility library for ZeroMQ
+language bindings and applications. To enable 'libzmq' compatibility, you
+must build your copy of libxs with the `--enable-libzmq` option to
+configure, or on Windows by building the appropriate solution file.
+
+For further details refer to the `doc/xs_zmq.html` or the 'xs_zmq(7)'
+manual page included with this distribution.
+
+NOTE: Enabling this option will *overwrite* any existing installation of
+`libzmq` on your system. 
+
+
+Reporting Bugs
+--------------
+
+To report a bug, sign up to the Crossroads I/O development discussion group
+at <http://groups.crossroads.io> and post a topic or send an email
+describing your problem.
+
+Prefix the subject of your post with `[BUG]` to catch the developers
+attention.
+
+To ensure that your report is dealt with promptly, please attach a minimal
+test case reproducing the bug, ideally written in C.
 
 
 Resources
 ---------
 
+The libxs development Git tree can be found on Github at
+<http://github.com/crossroads-io/libxs>.
+
+Development is coordinated on the <crossroads-dev@groups.crossroads.io>
+mailing list. Vist <http://groups.crossroads.io/> to join or view archives
+of previous discussion.
+
 Extensive documentation is provided with the distribution. Refer to
 doc/xs.html, or "man xs" after you have installed libxs on your system.
 
+Further resources, language bindings, tutorials, and more can be found on
+the Crossroads website at <http://www.crossroads.io/>.
+
+
 Copying
 -------
 
 Free use of this software is granted under the terms of the GNU Lesser General
 Public License (LGPL). For details see the files `COPYING` and `COPYING.LESSER`
 included with the libxs distribution.
+
+As a special exception, the copyright holders of libxs grant you the right
+to link the library statically with your software. Refer to the end of
+the `COPYING.LESSER` file included with the libxs distribution for details.
diff --git a/doc/xs.txt b/doc/xs.txt
index cf5ce14..8320dbd 100644
--- a/doc/xs.txt
+++ b/doc/xs.txt
@@ -16,12 +16,20 @@ SYNOPSIS
 
 DESCRIPTION
 -----------
-Crossroads I/O is a library which extends the standard
-socket interfaces with features traditionally provided by specialised
-_messaging middleware_ products. Crossroads sockets provide an abstraction of
-asynchronous  _message queues_, multiple _messaging patterns_, message
-filtering (_subscriptions_), seamless access to multiple _transport protocols_
-and more.
+Crossroads I/O is a library for building scalable and high performance
+distributed applications. It fits between classic BSD sockets,
+JMS/AMQP-style message queues, and enterprise message-oriented middleware.
+
+Crossroads I/O extends the standard socket interfaces with features
+traditionally provided by specialised _messaging middleware_ products.
+Crossroads sockets provide an abstraction of asynchronous  _message
+queues_, multiple _messaging patterns_, message filtering
+(_subscriptions_), seamless access to multiple _transport protocols_ and
+more.
+
+Crossroads I/O provides a native C API for applications. Support for many
+more languages is provided by the community through language bindings which
+can be found at the Crossroads website.
 
 This documentation presents an overview of Crossroads concepts, describes how
 Crossroads abstract standard sockets and provides a reference manual for the
@@ -40,18 +48,25 @@ Initialise Crossroads context::
 Terminate Crossroads context::
     linkxs:xs_term[3]
 
+Set Crossroads context options::
+    linkxs:xs_setctxopt[3]
+
 
 Thread safety
 ^^^^^^^^^^^^^
 A 'context' is thread safe and may be shared among as many application
-threads as necessary, without any additional locking required on the part of
-the caller.
-
-Individual Crossroads 'sockets' are _not_ thread safe except in the case where
-full memory barriers are issued when migrating a socket from one thread to
-another. In practice this means applications can create a socket in one thread
-with _xs_socket()_ and then pass it to a _newly created_ thread as part of
-thread initialization, for example via a structure passed as an argument to
+threads as necessary, without any additional locking required on the part
+of the caller.
+
+The individual 'sockets' within a 'context' are _not_ thread safe --
+applications may _not_ use a single 'socket' concurrently from multiple
+threads.
+
+A 'socket' _may_ be _migrated_ from one thread to another, by issuing a
+full memory barrier between individual calls on the 'socket'.  For example,
+this means applications can create a socket in one thread with
+_xs_socket()_ and then pass it to a _newly created_ thread as part of
+thread initialization via a structure passed as an argument to
 _pthread_create()_.
 
 
@@ -60,18 +75,28 @@ Multiple contexts
 Multiple 'contexts' may coexist within a single application. Thus, an
 application can use Crossroads directly and at the same time make use of any
 number of additional libraries or components which themselves make use of
-Crossroads as long as the above guidelines regarding thread safety are adhered
-to.
+Crossroads.
 
 
 Messages
 ~~~~~~~~
-A Crossroads message is a discrete unit of data passed between applications or
-components of the same application. Crossroads messages have no internal
+A Crossroads message is a discrete unit of data passed between applications
+or components of the same application. Crossroads messages have no internal
 structure and from the point of view of Crossroads themselves they are
 considered to be opaque binary data.
 
-The following functions are provided to work with messages:
+Applications using the Crossroads library send and receive messages
+directly from/to buffers provided by the application, using the Crossroads
+functions _xs_send()_ and _xs_recv()_.
+
+Alternatively, applications desiring zero-copy messaging and/or reference
+counted allocation of messages can use the message handling functions
+described in this section, and send and receive messages using
+_xs_sendmsg()_ and _xs_recvmsg()_ respectively.  These two approaches are
+interchangeable.
+
+The following functions are provided to work with messages using zero-copy
+and/or reference-counted allocation of messages:
 
 Initialise a message::
     linkxs:xs_msg_init[3]
@@ -89,6 +114,9 @@ Message manipulation::
     linkxs:xs_msg_copy[3]
     linkxs:xs_msg_move[3]
 
+Retrieve message option::
+    linkxs:xs_getmsgopt[3]
+
 
 Sockets
 ~~~~~~~
@@ -116,8 +144,12 @@ Sending and receiving messages::
     linkxs:xs_send[3]
     linkxs:xs_recv[3]
 
+Sending and receiving messages (zero-copy)::
+    linkxs:xs_sendmsg[3]
+    linkxs:xs_recvmsg[3]
+
 .Input/output multiplexing
-Crossroads provide a mechanism for applications to multiplex input/output events
+Crossroads provides a mechanism for applications to multiplex input/output events
 over a set containing both Crossroads sockets and standard sockets. This
 mechanism mirrors the standard _poll()_ system call, and is described in detail
 in linkxs:xs_poll[3].
@@ -143,6 +175,7 @@ Local inter-process communication transport::
 Local in-process (inter-thread) communication transport::
     linkxs:xs_inproc[7]
 
+
 ERROR HANDLING
 --------------
 The Crossroads library functions handle errors using the standard conventions
@@ -191,6 +224,10 @@ and Martin Lucina <martin@lucina.net>.
 
 COPYING
 -------
-Free use of Crossroads library is granted under the terms of the GNU Lesser
-General Public License (LGPL). For details see the files `COPYING` and
-`COPYING.LESSER` included with the Crossroads distribution.
+Free use of the Crossroads library software is granted under the terms of
+the GNU Lesser General Public License (LGPL). For details see the files
+`COPYING` and `COPYING.LESSER` included with the libxs distribution.
+
+As a special exception, the copyright holders of libxs grant you the right
+to link the library statically with your software. Refer to the end of
+the `COPYING.LESSER` file included with the libxs distribution for details.
diff --git a/doc/xs_init.txt b/doc/xs_init.txt
index 373822a..40a64bf 100644
--- a/doc/xs_init.txt
+++ b/doc/xs_init.txt
@@ -21,6 +21,28 @@ A 'context' is thread safe and may be shared among as many application
 threads as necessary, without any additional locking required on the part of
 the caller.
 
+The individual 'sockets' within a 'context' are _not_ thread safe --
+applications may _not_ use a single 'socket' concurrently from multiple
+threads.
+
+A 'socket' _may_ be _migrated_ from one thread to another, by issuing a
+full memory barrier between individual calls on the 'socket'.  For example,
+this means applications can create a socket in one thread with
+_xs_socket()_ and then pass it to a _newly created_ thread as part of
+thread initialization via a structure passed as an argument to
+_pthread_create()_.
+
+.Context options
+Context options may be set prior to creating the first socket within a
+'context', using the _xs_setctxopt()_ function. See linkxs:xs_setctxopt[3]
+for details on the available context options.
+
+.Multiple contexts
+Multiple 'contexts' may coexist within a single application. Thus, an
+application can use Crossroads directly and at the same time make use of any
+number of additional libraries or components which themselves make use of
+Crossroads.
+
 
 RETURN VALUE
 ------------
@@ -38,6 +60,7 @@ SEE ALSO
 --------
 linkxs:xs[7]
 linkxs:xs_term[3]
+linkxs:xs_setctxopt[3]
 
 
 AUTHORS
diff --git a/doc/xs_poll.txt b/doc/xs_poll.txt
index 37f7dc5..c809e28 100644
--- a/doc/xs_poll.txt
+++ b/doc/xs_poll.txt
@@ -10,7 +10,7 @@ xs_poll - input/output multiplexing
 SYNOPSIS
 --------
 
-*int xs_poll (xs_pollitem_t '*items', int 'nitems', long 'timeout');*
+*int xs_poll (xs_pollitem_t '*items', int 'nitems', int 'timeout');*
 
 
 DESCRIPTION
diff --git a/doc/xs_recv.txt b/doc/xs_recv.txt
index 26a6c54..5706432 100644
--- a/doc/xs_recv.txt
+++ b/doc/xs_recv.txt
@@ -29,22 +29,22 @@ function shall fail with 'errno' set to EAGAIN.
 
 Multi-part messages
 ~~~~~~~~~~~~~~~~~~~
-A Crossroads message is composed of 1 or more message parts. Each message
-part is an independent 'xs_msg_t' in its own right. Crossroads ensure atomic
-delivery of messages; peers shall receive either all _message parts_ of a
-message or none at all. The total number of message parts is unlimited except
-by available memory.
+A Crossroads message is composed of 1 or more message parts.  Crossroads
+ensures atomic delivery of messages; peers shall receive either all
+_message parts_ of a message or none at all. The total number of message
+parts is unlimited except by available memory.
 
 An application that processes multipart messages must use the _XS_RCVMORE_
-linkxs:xs_getsockopt[3] option after calling _xs_recv()_ to determine if
-there are further parts to receive.
+linkxs:xs_getsockopt[3] option on the 'socket' after calling _xs_recv()_ to
+determine if there are further parts to receive.
 
 RETURN VALUE
 ------------
-The _xs_recv()_ function shall return number of bytes in the message
-if successful. Note that the value can exceed the value of the 'len' parameter
-in case the message was truncated. If not successful the function shall return
-`-1` and set 'errno' to one of the values defined below.
+The _xs_recv()_ function shall return the number of bytes in the received
+message if successful. Note that the value can exceed the value of the
+'len' parameter, in this case the message was truncated. If not successful
+the function shall return `-1` and set 'errno' to one of the values defined
+below.
 
 
 ERRORS
@@ -79,8 +79,9 @@ assert (nbytes != -1);
 
 SEE ALSO
 --------
-linkxs:xs_recvmsg[3]
-linkxs:xs_send[3]
+Applications that wish to use zero-copy messaging must use
+linkxs:xs_recvmsg[3] instead of _xs_recv()_.
+
 linkxs:xs_sendmsg[3]
 linkxs:xs_getsockopt[3]
 linkxs:xs_socket[7]
@@ -89,6 +90,5 @@ linkxs:xs[7]
 
 AUTHORS
 -------
-+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
-+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
-
+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
diff --git a/doc/xs_recvmsg.txt b/doc/xs_recvmsg.txt
index 735fed0..4a88177 100644
--- a/doc/xs_recvmsg.txt
+++ b/doc/xs_recvmsg.txt
@@ -4,7 +4,7 @@ xs_recvmsg(3)
 
 NAME
 ----
-xs_recvmsg - receive a message part from a socket
+xs_recvmsg - receive a message part from a socket (zero-copy)
 
 
 SYNOPSIS
@@ -30,7 +30,7 @@ function shall fail with 'errno' set to EAGAIN.
 Multi-part messages
 ~~~~~~~~~~~~~~~~~~~
 A Crossroads message is composed of 1 or more message parts. Each message
-part is an independent 'xs_msg_t' in its own right. Crossroads ensure atomic
+part is an independent 'xs_msg_t' in its own right. Crossroads ensures atomic
 delivery of messages; peers shall receive either all _message parts_ of a
 message or none at all. The total number of message parts is unlimited except
 by available memory.
@@ -42,9 +42,9 @@ there are further parts to receive.
 
 RETURN VALUE
 ------------
-The _xs_recvmsg()_ function shall return number of bytes in the message
-if successful. Otherwise it shall return `-1` and set 'errno' to one of the
-values defined below.
+The _xs_recvmsg()_ function shall return the number of bytes in the
+received message if successful. Otherwise it shall return `-1` and set
+'errno' to one of the values defined below.
 
 
 ERRORS
@@ -106,8 +106,9 @@ do {
 
 SEE ALSO
 --------
-linkxs:xs_recv[3]
-linkxs:xs_send[3]
+Applications that do not require zero-copy messaging can use the simpler
+linkxs:xs_recv[3] instead of _xs_recvmsg()_.
+
 linkxs:xs_sendmsg[3]
 linkxs:xs_getsockopt[3]
 linkxs:xs_socket[7]
@@ -118,4 +119,3 @@ AUTHORS
 -------
 This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
 Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
-
diff --git a/doc/xs_send.txt b/doc/xs_send.txt
index f2d66e4..72bbf88 100644
--- a/doc/xs_send.txt
+++ b/doc/xs_send.txt
@@ -4,7 +4,7 @@ xs_send(3)
 
 NAME
 ----
-xs_send - send a message part  on a socket
+xs_send - send a message part on a socket
 
 
 SYNOPSIS
@@ -35,14 +35,13 @@ the 'socket' and Crossroads have assumed responsibility for the message.
 
 Multi-part messages
 ~~~~~~~~~~~~~~~~~~~
-A Crossroads message is composed of 1 or more message parts. Each message
-part is an independent 'xs_msg_t' in its own right. Crossroads ensure atomic
-delivery of messages; peers shall receive either all _message parts_ of a
-message or none at all. The total number of message parts is unlimited except
-by available memory.
+A Crossroads message is composed of 1 or more message parts. Crossroads
+ensures atomic delivery of messages; peers shall receive either all
+_message parts_ of a message or none at all. The total number of message
+parts is unlimited except by available memory.
 
 An application that sends multipart messages must use the _XS_SNDMORE_ flag
-when sending each data part except the final one.
+when sending each message part except the final one.
 
 
 RETURN VALUE
@@ -88,15 +87,15 @@ assert (rc == 2);
 
 SEE ALSO
 --------
-linkxs:xs_sendmsg[3]
+Applications that wish to use zero-copy messaging must use
+linkxs:xs_sendmsg[3] instead of _xs_send()_.
+
 linkxs:xs_recv[3]
-linkxs:xs_recvmsg[3]
 linkxs:xs_socket[7]
 linkxs:xs[7]
 
 
 AUTHORS
 -------
-+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
-+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
-
+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
diff --git a/doc/xs_sendmsg.txt b/doc/xs_sendmsg.txt
index 9478b4a..7445f25 100644
--- a/doc/xs_sendmsg.txt
+++ b/doc/xs_sendmsg.txt
@@ -4,7 +4,7 @@ xs_sendmsg(3)
 
 NAME
 ----
-xs_sendmsg - send a message part on a socket
+xs_sendmsg - send a message part on a socket (zero-copy)
 
 
 SYNOPSIS
@@ -48,6 +48,7 @@ by available memory.
 An application that sends multipart messages must use the _XS_SNDMORE_ flag
 when sending each data part except the final one.
 
+
 RETURN VALUE
 ------------
 The _xs_sendmsg()_ function shall return number of bytes in the message
@@ -104,8 +105,9 @@ rc = xs_sendmsg (socket, &part3, 0);
 
 SEE ALSO
 --------
-linkxs:xs_recv[3]
-linkxs:xs_recv[3]
+Applications that do not require zero-copy messaging can use the simpler
+linkxs:xs_send[3] instead of _xs_sendmsg()_.
+
 linkxs:xs_recvmsg[3]
 linkxs:xs_socket[7]
 linkxs:xs[7]
@@ -113,6 +115,5 @@ linkxs:xs[7]
 
 AUTHORS
 -------
-+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
-+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
-
+This man page was written by Martin Sustrik <sustrik@250bpm.com>, Martin
+Lucina <martin@lucina.net> and Pieter Hintjens <ph@imatix.com>.
diff --git a/doc/xs_setctxopt.txt b/doc/xs_setctxopt.txt
index d26d319..ccdd2db 100644
--- a/doc/xs_setctxopt.txt
+++ b/doc/xs_setctxopt.txt
@@ -12,22 +12,24 @@ SYNOPSIS
 --------
 *int xs_setctxopt (void '*context', int 'option_name', const void '*option_value', size_t 'option_len');*
 
-Caution: All options take effect only if set prior to creating the first socket.
 
 DESCRIPTION
 -----------
 The _xs_setctxopt()_ function shall set the option specified by the
-'option_name' argument to the value pointed to by the 'option_value' argument
-for the Crossroads context pointed to by the 'context' argument.
+'option_name' argument to the value pointed to by the 'option_value'
+argument, for the Crossroads context pointed to by the 'context' argument.
 The 'option_len' argument is the size of the option value in bytes.
 
+CAUTION: Context options take effect only if set with _xs_setctxopt()_
+prior to creating the first socket in a given 'context' with _xs_socket()_.
+
 The following options can be set with the _xs_setctxopt()_ function:
 
 
 XS_MAX_SOCKETS: Set maximum number of sockets
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The 'XS_MAX_SOCKETS' option shall set specify the maximum nuber of sockets
-that can be open at the same time.
+The 'XS_MAX_SOCKETS' option shall set the maximum nuber of sockets that can
+be simultaneously active in the given 'context'.
 
 [horizontal]
 Option value type:: int
@@ -36,8 +38,9 @@ Default value:: 512
 
 XS_IO_THREADS: Set number of worker threads
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-The 'XS_IO_THREADS' option shall set specify the size of the thread pool to
-handle I/O operations. The value should be at least 1.
+The 'XS_IO_THREADS' option shall set the size of the thread pool created by
+the given 'context' to handle I/O operations. The minimum value for this
+option is `1`.
 
 [horizontal]
 Option value type:: int
@@ -60,21 +63,23 @@ The provided 'context' was invalid.
 
 EXAMPLE
 -------
-.Setting maximal number of sockets to three.
+.Setting the number of I/O threads for a context to four.
 ----
-int val = 3;
-rc = xs_setctxopt (context, XS_CTX_MAX_SOCKETS, &val, sizeof (val));
+void *context = xs_init ();
+int io_threads = 4;
+rc = xs_setctxopt (context, XS_IO_THREADS, &io_threads, sizeof (io_threads));
 assert (rc == 0);
+/* The above call MUST be called before any socket is created in context */
+void *socket = xs_socket (context, XS_PUB);
 ----
 
 SEE ALSO
 --------
-linkxs:xs_getsockopt[3]
-linkxs:xs_setsockopt[3]
 linkxs:xs_init[3]
 linkxs:xs[7]
 
 
 AUTHORS
 -------
-This manual page was written by Martin Sustrik <sustrik@250bpm.com>.
+The Crossroads documentation was written by Martin Sustrik <sustrik@250bpm.com>
+and Martin Lucina <martin@lucina.net>.
diff --git a/doc/xs_zmq.txt b/doc/xs_zmq.txt
index 310ab64..570ef5e 100644
--- a/doc/xs_zmq.txt
+++ b/doc/xs_zmq.txt
@@ -72,6 +72,8 @@ Messages
 *int zmq_msg_init (zmq_msg_t '*msg');*
 *int zmq_msg_init_size (zmq_msg_t '*msg', size_t 'size');*
 *int zmq_msg_init_data (zmq_msg_t '*msg', void '*data', size_t 'size', zmq_free_fn '*ffn', void '*hint');*
+*size_t zmq_msg_size (zmq_msg_t '*msg');*
+*void *zmq_msg_data (zmq_msg_t '*msg');*
 *int zmq_msg_close (zmq_msg_t '*msg');*
 *int zmq_msg_copy (zmq_msg_t '*dest', zmq_msg_t '*src');*
 *int zmq_msg_move (zmq_msg_t '*dest', zmq_msg_t '*src');*