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register_ftrace                                             (Feedback)
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register_ftrace :
  (string * ((unit -> int) * (int -> unit)) * int) -> unit

SYNOPSIS
Registers a trace that is accessed by a set/get pair of functions.

KEYWORDS
tracing

LIBRARY
Feedback

DESCRIBE
A call to {register_ftrace(nm, (g,s), m)} registers an integer-valued
trace variable that is updated with the {s} function and whose value
is read with the {g} function.  The variable is given the name {nm}
and the variable’s maximum allowed value is {m}.  The trace’s default
is the value of {g()}, which is called just once as part of the
registration procedure.

FAILURE
Fails if the given name is already in use as a trace variable, or if
the maximum or the default value (returned by {g()}) is less than
zero.

COMMENTS
The two functions provide a more general way of accessing something
that may not be actually be an integer reference, even though this is
the interface that the various trace functions present.



SEEALSO
Feedback, Feedback.current_trace, Feedback.register_trace,
Feedback.register_btrace, Feedback.set_trace, Feedback.trace,
Feedback.traces.

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