diff options
Diffstat (limited to 'man/sd_bus_process.xml')
-rw-r--r-- | man/sd_bus_process.xml | 103 |
1 files changed, 73 insertions, 30 deletions
diff --git a/man/sd_bus_process.xml b/man/sd_bus_process.xml index b78192990c..66f22c29a6 100644 --- a/man/sd_bus_process.xml +++ b/man/sd_bus_process.xml @@ -8,7 +8,7 @@ Copyright © 2016 Julian Orth --> -<refentry id="sd_bus_process"> +<refentry id="sd_bus_process" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>sd_bus_process</title> @@ -33,7 +33,7 @@ <funcprototype> <funcdef>int <function>sd_bus_process</function></funcdef> <paramdef>sd_bus *<parameter>bus</parameter></paramdef> - <paramdef>sd_bus_message **<parameter>r</parameter></paramdef> + <paramdef>sd_bus_message **<parameter>ret</parameter></paramdef> </funcprototype> </funcsynopsis> </refsynopsisdiv> @@ -41,49 +41,92 @@ <refsect1> <title>Description</title> - <para> - <function>sd_bus_process()</function> drives the connection between the - message bus and the client. That is, it handles connecting, - authentication, and message processing. It should be called in a loop - until no further progress can be made or an error occurs. - </para> - - <para> - Once no further progress can be made, - <citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> - should be called. Alternatively the user can wait for incoming data on - the file descriptor returned by - <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + <para><function>sd_bus_process()</function> drives the connection between the client and the message bus. That is, + it handles connecting, authentication, and message processing. When invoked pending I/O work is executed, and + queued incoming messages are dispatched to registered callbacks. Each time it is invoked a single operation is + executed. It returns zero when no operations were pending and positive if a message was processed. When zero is + returned the caller should synchronously poll for I/O events before calling into + <function>sd_bus_process()</function> again. For that either user the simple, synchronous + <citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry> call, or hook up + the bus connection object to an external or manual event loop using + <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>. </para> - <para> - <function>sd_bus_process</function> processes at most one incoming - message per call. If the parameter <parameter>r</parameter> is not NULL - and the call processed a message, <code>*r</code> is set to this message. - The caller owns a reference to this message and should call - <citerefentry><refentrytitle>sd_bus_message_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> - when the message is no longer needed. If <parameter>r</parameter> is not - NULL, progress was made, but no message was processed, <code>*r</code> is - set to NULL. - </para> + <para><function>sd_bus_process()</function> processes at most one incoming message per call. If the parameter + <parameter>ret</parameter> is not <constant>NULL</constant> and the call processed a message, + <parameter>*ret</parameter> is set to this message. The caller owns a reference to this message and should call + <citerefentry><refentrytitle>sd_bus_message_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> when the + message is no longer needed. If <parameter>ret</parameter> is not NULL, progress was made, but no message was + processed, <parameter>*ret</parameter> is set to <constant>NULL</constant>.</para> + + <para>If a the bus object is connected to an + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry> event loop (with + <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry>), it is not + necessary to call <function>sd_bus_process()</function> directly as it is invoked automatically when + necessary.</para> </refsect1> <refsect1> <title>Return Value</title> - <para> - If progress was made, a positive integer is returned. If no progress was - made, 0 is returned. If an error occurs, a negative errno-style error code - is returned. - </para> + <para>If progress was made, a positive integer is returned. If no progress was made, 0 is returned. If an error + occurs, a negative <varname>errno</varname>-style error code is returned.</para> </refsect1> <refsect1> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>An invalid bus object was passed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The bus connection was allocated in a parent process and is being reused in a child process + after <function>fork()</function>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOTCONN</constant></term> + + <listitem><para>The bus connection has been terminated already.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ECONNRESET</constant></term> + + <listitem><para>The bus connection has been terminated just now.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EBUSY</constant></term> + + <listitem><para>This function is already being called, i.e. <function>sd_bus_process()</function> has been + called from a callback function that itself was called by + <function>sd_bus_process()</function>.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <xi:include href="libsystemd-pkgconfig.xml" /> + + <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_wait</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_message_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-event</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_attach_event</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> |