# File lib/rake.rb, line 349
349:     def invoke
350:       @lock.synchronize do
351:         if application.options.trace
352:           puts "** Invoke #{name} #{format_trace_flags}"
353:         end
354:         return if @already_invoked
355:         @already_invoked = true
356:         invoke_prerequisites
357:         execute if needed?
358:       end
359:     end