class ActiveSupport::Testing::Performance::Metrics::GcTime

def measure
  ManagementFactory.garbage_collector_mx_beans.inject(0) { |total_time, current_gc| total_time += current_gc.collection_time } / 1000.0 # seconds
end

def measure
  (loopback.get("system.gc.full.wallclock").last + loopback.get("system.gc.young.wallclock").last) / 1000.0
end

def measure
  RubyProf.measure_gc_time / 1000.0 / 1000.0
end

def measure
  GC::Profiler.total_time
end