- </para>
-
- <para>The memory pointed at by <parameter>p</parameter> is copied
- into the memory area containing the message and may be changed
- after this call.</para>
-
- <para>The
- <function>sd_bus_message_append_array_memfd</function> function appends
- items to message <parameter>m</parameter>, similarly to
- <function>sd_bus_message_append_array</function>. Contents of the
- memory file descriptor <parameter>memfd</parameter> are used as
- the contents of the array. Their size must be a multiple of the
- size of the type <parameter>type</parameter>.</para>
-
- <para>The descriptor specified with <parameter>memfd</parameter>
- will be sealed and cannot be modified after this call.</para>
-
- <para>The
- <function>sd_bus_message_append_array_iovec</function> function appends
- items to message <parameter>m</parameter>, similarly to
- <function>sd_bus_message_append_array</function>. Contents of the
- iovec <parameter>iov</parameter> are used as the contents of the
- array. The total size of <parameter>iov</parameter> payload (the
- sum of <structfield>iov_len</structfield> fields) must be a multiple
- of the size of the type <parameter>type</parameter>.</para>
-
- <para>The <parameter>iov</parameter> argument must point to
- <parameter>n</parameter> <structname>struct iovec</structname>
- structures. Each structure may have the
- <structname>iov_base</structname> field set, in which case the
- memory pointed to will be copied into the message, or unset, in
- which case a block of zeros of length
+ The memory pointed to by <parameter>p</parameter> is copied into
+ the memory area containing the message and stays in possession of
+ the caller. The caller may hence freely change the data after this
+ call without affecting the message the array was appended
+ to.</para>
+
+ <para>The <function>sd_bus_message_append_array_memfd()</function>
+ function appends an array of a trivial type to message
+ <parameter>m</parameter>, similar to
+ <function>sd_bus_message_append_array()</function>. The contents
+ of the memory file descriptor <parameter>memfd</parameter>
+ starting at the specified offset and of the specified size is
+ used as the contents of the array. The offset and size must be a
+ multiple of the size of the type
+ <parameter>type</parameter>. However, as a special exception, if
+ the offset is specified as zero and the size specified as
+ UINT64_MAX the full memory file descriptor contents is used. The
+ memory file descriptor is sealed by this call if it has not been
+ sealed yet, and cannot be modified after this call. See
+ <citerefentry
+ project='man-pages'><refentrytitle>memfd_create</refentrytitle><manvolnum>2</manvolnum></citerefentry>
+ for details about memory file descriptors. Appending arrays with
+ memory file descriptors enables efficient zero-copy data transfer,
+ as the memory file descriptor may be passed as-is to the
+ destination, without copying the memory in it to the destination
+ process. Not all protocol transports support passing memory file
+ descriptors between participants, in which case this call will
+ automatically fall back to copying. Also, as memory file
+ descriptor passing is inefficient for smaller amounts of data,
+ copying might still be enforced even where memory file descriptor
+ passing is supported.</para>
+
+ <para>The <function>sd_bus_message_append_array_iovec()</function>
+ function appends an array of a trivial type to the message
+ <parameter>m</parameter>, similar to
+ <function>sd_bus_message_append_array()</function>. Contents of
+ the I/O vector array <parameter>iov</parameter> are used as the
+ contents of the array. The total size of
+ <parameter>iov</parameter> payload (the sum of
+ <structfield>iov_len</structfield> fields) must be a multiple of
+ the size of the type <parameter>type</parameter>. The
+ <parameter>iov</parameter> argument must point to
+ <parameter>n</parameter> I/O vector structures. Each structure may
+ have the <structname>iov_base</structname> field set, in which
+ case the memory pointed to will be copied into the message, or
+ unset (set to zero), in which case a block of zeros of length