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TracePoint is a Binding with the addition of event information. In theory it would function very well as the join-point for AOP. In practice it provides a better approach to #set_trace_func.

FEATURES

• More versatile than #set_trace_func.
• Easy to set multiple traces.

SYNOPSIS

Using TracePoint is simply a matter of setting the #trace procedure. For example to watch everything that happens during a Ruby process:

   TracePoint.trace do |tp|
     puts "#{tp.self.class}\t#{tp.callee}\t#{tp.event}\t#{tp.return?}"
   end

   TracePoint.activate

   1 + 1

Produces:

   Object       line       false
   Fixnum   +   c-call     false
   Fixnum   +   c-return   false

Tracing can be deactived and reactivated on the fly by calling #deactivate and #activate.

To add additional trace procedures, simply call the #trace method again. Trace procedures can also be named by providing a name argument to the #trace method. This allows traces to be added and removed without affecting other traces.

   TracePoint.trace(:class_trace) do |tp|
     puts tp.self.class
   end

   TracePoint.trace(:method_trace) do |tp|
     puts tp.callee
   end

   # ...

TracePoint.clear(:class_trace)

Calling #clear with no arguments will remove all trace procedures and deactivate tracing.

Please see the API documentation for more information.