Feature #6649
closed
Add new set_trace_func events "b-call", "b-return"
Description
=begin
= Abstract
Add new events "b-call", "b-return" for set_trace_func().
When block is invoked, then "b-call" is called.
When block is finished, then "b-return" is called.
= Background
set_trace_func() has several events:
- "line"
- "call", "return"
- "c-call", "c-return"
- "class", "end"
- "raise"
With above events, we can trace execution. However, we can't trace block invocation because there are no events related to block invocation and return from block.
For example, performance profiler using set_trace_func() has problem in such case:
def m1
yield
end
def m2
m1 do
# long time process
end
end
A method m1' doesn't consume time, but m2' consume long time (within block).
However, the profiler detects that the method `m1' consumes long time.
= Proposal
Add "b-call" and "b-return" events for set_trace_func. "b-call" is for block invocation. "b-return" is for returning from block.
Parameters:
- event: "b-call" or "b-return"
- file: filename of block
- line: start/end line number of block
- id: block owner method id
- binding: binding of block
- klass: block owner class
= Concerns
- This proposal breaks 100% compatibility. It seems problem (*1).
- It will make some runtime overhead (slow down).
- parameters id and klass is appropriate?
(*1) Making an alternative API which can replace set_trace_func() (correctly speaking, set_trace_func() can be implemented with this new API) is another proposal.
as usual, the method name is temporary name¶
set_trace_func2(lamda{|info|
info.event
...
}
=end
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