[sysprof] libsysprof: use a{sv} for future profiler specific options

[Christian Hergert <chergert src gnome org>]

commit a74e6daa3b0403b346a51bcab3d94c3e543e4c63
Author: Christian Hergert <chergert redhat com>
Date:   Wed May 29 15:08:17 2019 -0700

    libsysprof: use a{sv} for future profiler specific options
    
    We may need this in the future to send backend-specific options to the
    profiler peer.

 src/libsysprof/sysprof-proxy-source.c |  2 +-
 src/org.gnome.Sysprof3.Profiler.xml   | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+), 1 deletion(-)
---
diff --git a/src/libsysprof/sysprof-proxy-source.c b/src/libsysprof/sysprof-proxy-source.c
index 536c51e..6c65702 100644
--- a/src/libsysprof/sysprof-proxy-source.c
+++ b/src/libsysprof/sysprof-proxy-source.c
@@ -229,7 +229,7 @@ sysprof_proxy_source_monitor (SysprofProxySource *self,
                                             self->object_path,
                                             "org.gnome.Sysprof3.Profiler",
                                             "Start",
-                                            g_variant_new ("(h)", handle),
+                                            g_variant_new ("(a{sv}h)", NULL, handle),
                                             G_VARIANT_TYPE ("()"),
                                             G_DBUS_CALL_FLAGS_NO_AUTO_START,
                                             -1,
diff --git a/src/org.gnome.Sysprof3.Profiler.xml b/src/org.gnome.Sysprof3.Profiler.xml
index 619f79b..c5c5e8a 100644
--- a/src/org.gnome.Sysprof3.Profiler.xml
+++ b/src/org.gnome.Sysprof3.Profiler.xml
@@ -2,9 +2,28 @@
 "http://www.freedesktop.org/standards/dbus/1.0/introspect.dtd";>
 <node>
   <interface name="org.gnome.Sysprof3.Profiler">
+    <!--
+      Start:
+      @options: an a{sv} of implementation specific options
+      @fd: a file-descriptor for the profiler to write to
+
+      Start the profiler if it is not running.
+
+      If the profiler is already running, this method should return
+      an error so that the caller knows not to call Stop().
+
+      It is also suggested that implementations disable profiling if
+      they lose the peer connection.
+    -->
     <method name="Start">
+      <arg type="a{sv}" name="options" direction="in"/>
       <arg type="h" name="fd" direction="in"/>
     </method>
+    <!--
+      Stop:
+
+      Stop the profiler if it is running.
+    -->
     <method name="Stop"/>
   </interface>
 </node>