Performance Testing using DTrace

Slides from the presentation given at CocoaHeads Berlin February 2018 meet up.

Transcript

1. PERFORMANCE TESTING USING DTRACE
2. MOTIVATION
3. NON-FUNCTIONAL SOFTWARE REQUIREMENTS
4. BACKSTORY: XING.APP
5. MEASURING PERFORMANCE WITH XCODE > CACurrentMediaTime / mach_absolute_time() > dispatch_benchmark > -[XCTestCase measureBlock:]
6. INSTRUMENTS.APP
9. DTRACE
10. D LANGUAGE provider:module:function:name / predicate / { action statements }
11. ASOCCIATIVE ARRAYS instr$target:::benchmark_begin { time = timestamp; tag = copyinstr(arg0); tag_times[tag] = time; } instr$target:::benchmark_end / tag_times[copyinstr(arg0)] != 0 / { tag = copyinstr(arg0); time = (timestamp - tag_times[tag]); printf("%s:%d\n", tag, time); }
12. PROVIDERS pid1337:libdl:dlopen:return objc7331:NSDate:-dateByAddingTimeInterval?:entry proc:::exec-success
13. VARS > execname -> process name > pid -> current pid > timestamp -> nanoseconds > args[0]...[N] -> probe arguments > probemod -> probe module > probefunc -> probe function
16. INSTRUMENTS.APP IN THE CLI > instruments > iprofiler > UIAutomation
17. ORCHESTRATION 1. Prepare the software 2. Run the software 3. Run DTrace 4. Build performance report
18. instr
19. ORCHESTRATION 1. Prepare the software 2. Run the software 3. Run DTrace 4. Build performance report
20. gem install instrumentality bundle exec instr profile $INSTRUMENT $TARGET_PROCESS (--interactive)
21. DEMO
22. CLOSING > /usr/share/examples/DTTk > Lots of information out there! objc.io, Oracle, Apple, Facebook > Software instrumentation using the iOS Simulator is far from ideal > Run DTrace on your own systems and get surprised by what's happening!
23. LINKS > objc.io: DTrace > instr > Jenkins demo: GitHub