class RubyProf::Profile

def merge!


ran for 50 seconds.
are 10 workers that each run for 5 seconds, merged results will show one thread that
Note the reported time will be much greater than the actual wall time. For example, if there

overwhelming. Using +merge!+ will combine the worker times together into one result.
If there are tens or hundreds of workers, viewing results per worker thread/fiber can be
when profiling code that uses a main thread/fiber to distribute work to multiple workers.
Merges RubyProf threads whose root call_trees reference the same target method. This is useful

merge! -> self
call-seq: 
def merge!
  # First group threads by their root call tree target (method). If the methods are
  # different than there is nothing to merge
  grouped = threads.group_by do |thread|
    thread.call_tree.target
  end
  # For each target, get the first thread. Then loop over the remaining threads,
  # and merge them into the first one and ten delete them. So we will be left with
  # one thread per target.
  grouped.each do |target, threads|
    thread = threads.shift
    threads.each do |other_thread|
      thread.merge!(other_thread)
      remove_thread(other_thread)
    end
    thread
  end
  self
end