Macro vthread_duration_begin 

macro_rules! vthread_duration_begin {
    ($category:expr, $name:expr, $vthread_name:expr, $vthread_id:expr $(, $key:expr => $val:expr)* $(,)?) => { ... };
}

Convenience macro for the vthread_duration_begin function, which writes events to a track specified by vthread_name and vthread_id.

Examples:

vthread_duration_begin!("foo", "bar", "my_vthread", 123, "x" => 5, "y" => "boo");

const FOO: &'static str = "foo";
const BAR: &'static str = "bar";
const VTHREAD_NAME: &'static str = "my_vthread";
vthread_duration_begin!(FOO, BAR, VTHREAD_NAME, 123, "x" => 5, "y" => "boo");