spinlock.go

// Package spinlock provides a low level implementation of spinlock in
// assembly. Also, it provides fallback to implementation based on built-in
// atomics.
//
// On my private laptop benchmark results are the following. Measured time is
// wall time.
//
//  goos: linux
//  goarch: amd64
//  pkg: github.com/daskol/spinlock
//  BenchmarkMutex/1-4                       50000000	        37.7 ns/op
//  BenchmarkMutex/2-4                       30000000	        52.4 ns/op
//  BenchmarkMutex/4-4                       20000000	        64.4 ns/op
//  BenchmarkMutex/8-4                       20000000	        83.8 ns/op
//  BenchmarkMutex/16-4                      20000000	        91.2 ns/op
//  BenchmarkSpinlockInAsm/1-4              100000000	        22.1 ns/op
//  BenchmarkSpinlockInAsm/2-4              100000000	        22.1 ns/op
//  BenchmarkSpinlockInAsm/4-4              100000000	        22.1 ns/op
//  BenchmarkSpinlockInAsm/8-4              100000000	        22.8 ns/op
//  BenchmarkSpinlockInAsm/16-4         	100000000	        23.6 ns/op
//  BenchmarkSpinlockInGo/1-4           	 50000000	        28.0 ns/op
//  BenchmarkSpinlockInGo/2-4           	 50000000	        27.8 ns/op
//  BenchmarkSpinlockInGo/4-4           	 50000000	        28.1 ns/op
//  BenchmarkSpinlockInGo/8-4           	 50000000	        28.7 ns/op
//  BenchmarkSpinlockInGo/16-4          	 50000000	        29.5 ns/op
//  BenchmarkSpinlockThin/1-4           	100000000	        17.8 ns/op
//  BenchmarkSpinlockThin/2-4           	100000000	        17.5 ns/op
//  BenchmarkSpinlockThin/4-4           	100000000	        17.6 ns/op
//  BenchmarkSpinlockThin/8-4           	100000000	        18.0 ns/op
//  BenchmarkSpinlockThin/16-4          	100000000	        18.4 ns/op
//  PASS
//  ok  	github.com/daskol/spinlock	39.539s
//
// The fastest implementation based on free function Lock()/Unlock(). However
// it is two times slower than spinlock implemented in modern C++.
//
//  Run on (4 X 3400 MHz CPU s)
//  CPU Caches:
//    L1 Data 32K (x2)
//    L1 Instruction 32K (x2)
//    L2 Unified 256K (x2)
//    L3 Unified 4096K (x1)
//  ---------------------------------------------------------------
//  Benchmark                        Time           CPU Iterations
//  ---------------------------------------------------------------
//  run/real_time/threads:1          9 ns          9 ns   74377642
//  run/real_time/threads:2          9 ns         19 ns   74705518
//  run/real_time/threads:4         11 ns         44 ns   64348172
//  run/real_time/threads:8         10 ns         43 ns   7931257
package spinlock