Everything should be made as simple as possible, but not any simpler —Albert Einstein
This definitely breaks the ‘but not any simpler” part. (No the benchmarks arent nano scale, just the library.)
Uses volatile reads/write to blackhole data and try to make sure all reads of arguments isn’t elided.
Uses clock_gettime() call using MONOTONIC_RAW to get a nano second count. This should be one fo the fastest reliable ways. If can be guaranteed a non-broken TSC (looking at you AMD), RDTSCP+FENCE is a possibility for tighter timings.
Only checks times at start and stop of workload, not on every invocation. While this does include the looping inside the call there are plans to try to get a baseline and deduct it. Doing the timing calls on every invocation just adds too much noise.
Currently has two timing modes: by count and by time. Either give it an invocation count to run to or a millisecond value to run to. The timing is done in a separate thread to not interfere with the running of the benched function.
And each of those has two call modes: since value over and over again or give an array of values and it will make a fixed number of passes or keep doing full passes until the timer expires.
- [X] find empty run baseline
- [X] per fix time interval
- [X] max timed runs
- [X] other threads to do the timing calls
- [ ] better interface
- [ ] warmup
- [ ] cache flushing (opposide of warmup)
- [ ] better reporting
- [X] void returning functions
- [X] functions with no arguments
- [ ] steal more JMH ideas
There is still some issues with optimizations creeping into the wrong places