Convenience macro for the duration function that can be used to trace
the duration of a scope. If you need finer grained control over when a
duration starts and stops, see duration_begin and duration_end.
Macro for constructing TraceFutureArgs. The trace arguments won’t be constructed if the
category is not enabled. If the category becomes enabled while the TraceFuture is still alive
then the duration events will still be written but without the trace arguments.
Writes a flow begin event with the specified id.
This event may be followed by flow steps events and must be matched by
a flow end event with the same category, name, and id.