Feature #3809

allow multiple set_trace_func() calls

Added by Suraj Kurapati about 5 years ago. Updated about 3 years ago.

Assignee:Yukihiro Matsumoto



The current set_trace_func() method in Ruby 1.8 and 1.9 cannot be safely
called multiple times because each call overwrites the current trace_func.

Please consider adding a mechanism, such as the multitrace library1, to
allow users to attach multiple tracing functions simultaneously to Ruby.

An alternative to the multitrace library1 is to add some new methods:

  • attach_trace_func(proc) #=> proc
  • detach_trace_func(proc) #=> proc

When you call attach_trace_func(), it will register your tracing
function and return it. You can pass the same tracing function
later to detach_trace_func() to unregister it.

Here is a convoluted example:

detach_trace_func(attach_trace_func(proc {}))

Here is a more realistic example:

foo = proc {}
bar = proc {}
attach_trace_func foo
# ...
attach_trace_func bar
# ...
detach_trace_func foo
detach_trace_func bar

Thanks for your consideration.



#1 Updated by Shyouhei Urabe about 5 years ago

  • Status changed from Open to Assigned



#2 Updated by Yusuke Endoh about 3 years ago

  • Description updated (diff)
  • Target version set to next minor

#3 Updated by Thomas Sawyer about 3 years ago

Isn't this taken care of by the new TracePoint API?

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