diff options
Diffstat (limited to 'man/sd_bus_request_name.xml')
| -rw-r--r-- | man/sd_bus_request_name.xml | 140 |
1 files changed, 83 insertions, 57 deletions
diff --git a/man/sd_bus_request_name.xml b/man/sd_bus_request_name.xml index f44cfdb1ac..9e668f0b02 100644 --- a/man/sd_bus_request_name.xml +++ b/man/sd_bus_request_name.xml @@ -46,7 +46,9 @@ <refnamediv> <refname>sd_bus_request_name</refname> + <refname>sd_bus_request_name_async</refname> <refname>sd_bus_release_name</refname> + <refname>sd_bus_release_name_async</refname> <refpurpose>Request or release a well-known service name on a bus</refpurpose> </refnamediv> @@ -62,70 +64,102 @@ </funcprototype> <funcprototype> + <funcdef>int <function>sd_bus_request_name_async</function></funcdef> + <paramdef>sd_bus *<parameter>bus</parameter></paramdef> + <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef> + <paramdef>const char *<parameter>name</parameter></paramdef> + <paramdef>uint64_t <parameter>flags</parameter></paramdef> + <paramdef>sd_bus_message_handler_t <parameter>callback</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> + + <funcprototype> <funcdef>int <function>sd_bus_release_name</function></funcdef> <paramdef>sd_bus *<parameter>bus</parameter></paramdef> <paramdef>const char *<parameter>name</parameter></paramdef> </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_release_name_async</function></funcdef> + <paramdef>sd_bus *<parameter>bus</parameter></paramdef> + <paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef> + <paramdef>const char *<parameter>name</parameter></paramdef> + <paramdef>sd_bus_message_handler_t <parameter>callback</parameter></paramdef> + <paramdef>void *<parameter>userdata</parameter></paramdef> + </funcprototype> </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> - <para><function>sd_bus_request_name()</function> requests a - well-known service name on a bus. It takes a bus connection, a - valid bus name and a flags parameter. The flags parameter is a - combination of the following flags:</para> + <para><function>sd_bus_request_name()</function> requests a well-known service name on a bus. It takes a bus + connection, a valid bus name and a flags parameter. The flags parameter is a combination of the following + flags:</para> <variablelist> <varlistentry> <term><varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname></term> - <listitem><para>After acquiring the name successfully, permit - other peers to take over the name when they try to acquire it - with the <varname>SD_BUS_NAME_REPLACE_EXISTING</varname> flag - set. If <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> is - not set on the original request, such a request by other peers - will be denied.</para></listitem> + <listitem><para>After acquiring the name successfully, permit other peers to take over the name when they try + to acquire it with the <varname>SD_BUS_NAME_REPLACE_EXISTING</varname> flag set. If + <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> is not set on the original request, such a request by other + peers will be denied.</para></listitem> </varlistentry> <varlistentry> <term><varname>SD_BUS_NAME_REPLACE_EXISTING</varname></term> - <listitem><para>Take over the name if it is already acquired - by another peer, and that other peer has permitted takeover by - setting <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> while - acquiring it.</para></listitem> + <listitem><para>Take over the name if it is already acquired by another peer, and that other peer has permitted + takeover by setting <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> while acquiring it.</para></listitem> </varlistentry> <varlistentry> <term><varname>SD_BUS_NAME_QUEUE</varname></term> - <listitem><para>Queue the acquisition of the name when the - name is already taken.</para></listitem> + <listitem><para>Queue the acquisition of the name when the name is already taken.</para></listitem> </varlistentry> </variablelist> - <para><function>sd_bus_release_name()</function> releases an - acquired well-known name. It takes a bus connection and a valid - bus name as parameters.</para> + <para><function>sd_bus_request_name()</function> operates in a synchronous fashion: a message requesting the name + is sent to the bus broker, and the call waits until the broker responds.</para> + + <para><function>sd_bus_request_name_async()</function> is an asynchronous version of of + <function>sd_bus_release_name()</function>. Instead of waiting for the request to complete, the request message is + enqueued. The specified <parameter>callback</parameter> will be called when the broker's response is received. If + the parameter is specified as <constant>NULL</constant> a default implementation is used instead which will + terminate the connection when the name cannot be acquired. The function returns a slot object in its + <parameter>slot</parameter> parameter — if it is passed as non-<constant>NULL</constant> — which may be used as a + reference to the name request operation. Use + <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> to destroy + this reference. Note that destroying the reference will not unregister the name, but simply ensure the specified + callback is no longer called.</para> + + <para><function>sd_bus_release_name()</function> releases an acquired well-known name. It takes a bus connection + and a valid bus name as parameters. This function operates synchronously, sending a release request message to the + bus broker and waiting for it to reply.</para> + + <para><function>sd_bus_release_name_async()</function> is an asynchronous version of + <function>sd_bus_release_name()</function>. The specified <parameter>callback</parameter> function is called when + the name has been released successfully. If specified as <constant>NULL</constant> a generic implementation is used + that ignores the result of the operation. As above, the <parameter>slot</parameter> (if + non-<constant>NULL</constant>) is set to an object that may be used to reference the operation.</para> + + <para>These functions are supported only on bus connections, i.e. connections to a bus broker and not on direct + connections.</para> </refsect1> <refsect1> <title>Return Value</title> - <para>On success, these calls return 0 or a positive integer. On - failure, these calls return a negative errno-style error - code.</para> - - <para>If <varname>SD_BUS_NAME_QUEUE</varname> is specified, - <function>sd_bus_request_name()</function> will return 0 when the - name is already taken by another peer and the client has been - added to the queue for the name. In that case, the caller can - subscribe to <literal>NameOwnerChanged</literal> signals to be - notified when the name is successfully acquired. - <function>sd_bus_request_name()</function> returns > 0 when the - name has immediately been acquired successfully.</para> + <para>On success, these calls return 0 or a positive integer. On failure, these calls return a negative errno-style + error code.</para> + + <para>If <varname>SD_BUS_NAME_QUEUE</varname> is specified, <function>sd_bus_request_name()</function> will return + 0 when the name is already taken by another peer and the client has been added to the queue for the name. In that + case, the caller can subscribe to <literal>NameOwnerChanged</literal> signals to be notified when the name is + successfully acquired. <function>sd_bus_request_name()</function> returns > 0 when the name has immediately + been acquired successfully.</para> </refsect1> <refsect1> @@ -137,56 +171,50 @@ <varlistentry> <term><constant>-EALREADY</constant></term> - <listitem><para>The caller already is the owner of the - specified name.</para></listitem> + <listitem><para>The caller already is the owner of the specified name.</para></listitem> </varlistentry> <varlistentry> <term><constant>-EEXIST</constant></term> - <listitem><para>The name has already been acquired by a - different peer, and SD_BUS_NAME_REPLACE_EXISTING was not - specified or the other peer did not specify - SD_BUS_NAME_ALLOW_REPLACEMENT while acquiring the + <listitem><para>The name has already been acquired by a different peer, and SD_BUS_NAME_REPLACE_EXISTING was + not specified or the other peer did not specify SD_BUS_NAME_ALLOW_REPLACEMENT while acquiring the name.</para></listitem> </varlistentry> <varlistentry> <term><constant>-ESRCH</constant></term> - <listitem><para>It was attempted to release a name that is - currently not registered on the bus.</para></listitem> + <listitem><para>It was attempted to release a name that is currently not registered on the + bus.</para></listitem> </varlistentry> <varlistentry> <term><constant>-EADDRINUSE</constant></term> - <listitem><para>It was attempted to release a name that is - owned by a different peer on the bus.</para></listitem> + <listitem><para>It was attempted to release a name that is owned by a different peer on the + bus.</para></listitem> </varlistentry> <varlistentry> <term><constant>-EINVAL</constant></term> - <listitem><para>A specified parameter is invalid. This is also - generated when the requested name is a special service name - reserved by the D-Bus specification, or when the operation is - requested on a connection that does not refer to a - bus.</para></listitem> + <listitem><para>A specified parameter is invalid. This is also generated when the requested name is a special + service name reserved by the D-Bus specification, or when the operation is requested on a connection that does + not refer to a bus.</para></listitem> </varlistentry> <varlistentry> <term><constant>-ENOTCONN</constant></term> - <listitem><para>The bus connection has been - disconnected.</para></listitem> + <listitem><para>The bus connection has been disconnected.</para></listitem> </varlistentry> <varlistentry> <term><constant>-ECHILD</constant></term> - <listitem><para>The bus connection has been created in a - different process than the current one.</para></listitem> + <listitem><para>The bus connection has been created in a different process than the current + one.</para></listitem> </varlistentry> </variablelist> </refsect1> @@ -194,12 +222,9 @@ <refsect1> <title>Notes</title> - <para>The <function>sd_bus_acquire_name()</function> and - <function>sd_bus_release_name()</function> interfaces are - available as a shared library, which can be compiled and linked to - with the - <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> - file.</para> + <para>The <function>sd_bus_acquire_name()</function> and the other interfaces described here are available as a + shared library, which can be compiled and linked to with the <constant>libsystemd</constant> <citerefentry + project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> file.</para> </refsect1> <refsect1> @@ -208,7 +233,8 @@ <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, - <citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry> + <citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> |