The following are examples of rb_flowtime.d. This is a simple script to trace the flow of Ruby methods. Here it traces the example program, Code/Ruby/func_abc.rb # rb_flowtime.d C TIME(us) FILE DELTA(us) -- CLASS::METHOD 0 3066547402640 func_abc.rb 2 -> Module::method_added 0 3066547402662 func_abc.rb 22 <- Module::method_added 0 3066547402683 func_abc.rb 20 -> Module::method_added 0 3066547402693 func_abc.rb 9 <- Module::method_added 0 3066547402707 func_abc.rb 14 -> Module::method_added 0 3066547402716 func_abc.rb 9 <- Module::method_added 0 3066547402729 func_abc.rb 12 -> Object::func_a 0 3066547402740 func_abc.rb 10 -> Object::print 0 3066547402759 func_abc.rb 18 -> IO::write 0 3066547402860 func_abc.rb 101 <- IO::write 0 3066547402871 func_abc.rb 10 <- Object::print 0 3066547402881 func_abc.rb 10 -> Object::sleep 0 3066548410630 func_abc.rb 1007749 <- Object::sleep 0 3066548410660 func_abc.rb 30 -> Object::func_b 0 3066548410679 func_abc.rb 18 -> Object::print 0 3066548410689 func_abc.rb 10 -> IO::write 0 3066548410730 func_abc.rb 40 <- IO::write 0 3066548410740 func_abc.rb 9 <- Object::print 0 3066548410749 func_abc.rb 9 -> Object::sleep 0 3066549420724 func_abc.rb 1009974 <- Object::sleep 0 3066549420755 func_abc.rb 30 -> Object::func_c 0 3066549420773 func_abc.rb 18 -> Object::print 0 3066549420783 func_abc.rb 10 -> IO::write 0 3066549420825 func_abc.rb 41 <- IO::write 0 3066549420835 func_abc.rb 9 <- Object::print 0 3066549420844 func_abc.rb 9 -> Object::sleep 0 3066550430611 func_abc.rb 1009766 <- Object::sleep 0 3066550430635 func_abc.rb 24 <- Object::func_c 0 3066550430645 func_abc.rb 10 <- Object::func_b 0 3066550430655 func_abc.rb 9 <- Object::func_a ^C The fifth column is indented by 2 spaces to show when a new method begins. This shows which method is calling which. The TIME(us) column shows time since boot. The DELTA(us) column shows time from that line to the previous line, and so can be a bit tricky to read. For example, the seventh line of data output (skipping the header) reads as "the time from func_a beginning to calling the print method was 10 microseconds". The FILE column shows file that was being executed. If the output looks shuffled, check the CPU "C" and "TIME" columns, and post sort based on TIME if necessary. See Notes/ALLflow_notes.txt for important notes about reading flow outputs.