进行基准测试如何运作

Question

I've got my Go benchmark working with my API calls but I'm not exactly sure what it means below:

$ go test intapi -bench=. -benchmem -cover -v -cpuprofile=cpu.out
=== RUN TestAuthenticate
--- PASS: TestAuthenticate (0.00 seconds)
PASS
BenchmarkAuthenticate      20000            105010 ns/op            3199 B/op         49 allocs/op
coverage: 0.0% of statements
ok      intapi  4.349s

How does it know how many calls it should make? I do have a loop with b.N as size of the loop but how does Golang know how many to run?

Also I now have cpu profile file. How can I use this to view it?

Answer 1

From TFM:

The benchmark function must run the target code b.N times. The benchmark package will vary b.N until the benchmark function lasts long enough to be timed reliably.