wireguard-go/device/pools_test.go
Jason A. Donenfeld c3bde5f590 device: benchmark the waitpool to compare it to the prior channels
Here is the old implementation:

    type WaitPool struct {
        c chan interface{}
    }

    func NewWaitPool(max uint32, new func() interface{}) *WaitPool {
        p := &WaitPool{c: make(chan interface{}, max)}
        for i := uint32(0); i < max; i++ {
            p.c <- new()
        }
        return p
    }

    func (p *WaitPool) Get() interface{} {
        return <- p.c
    }

    func (p *WaitPool) Put(x interface{}) {
        p.c <- x
    }

It performs worse than the new one:

    name         old time/op  new time/op  delta
    WaitPool-16  16.4µs ± 5%  15.1µs ± 3%  -7.86%  (p=0.008 n=5+5)

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-02-03 16:59:29 +01:00

83 lines
1.6 KiB
Go

/* SPDX-License-Identifier: MIT
*
* Copyright (C) 2019-2021 WireGuard LLC. All Rights Reserved.
*/
package device
import (
"math/rand"
"runtime"
"sync"
"sync/atomic"
"testing"
"time"
)
func TestWaitPool(t *testing.T) {
var wg sync.WaitGroup
trials := int32(100000)
workers := runtime.NumCPU() + 2
if workers-4 <= 0 {
t.Skip("Not enough cores")
}
p := NewWaitPool(uint32(workers-4), func() interface{} { return make([]byte, 16) })
wg.Add(workers)
max := uint32(0)
updateMax := func() {
count := atomic.LoadUint32(&p.count)
if count > p.max {
t.Errorf("count (%d) > max (%d)", count, p.max)
}
for {
old := atomic.LoadUint32(&max)
if count <= old {
break
}
if atomic.CompareAndSwapUint32(&max, old, count) {
break
}
}
}
for i := 0; i < workers; i++ {
go func() {
defer wg.Done()
for atomic.AddInt32(&trials, -1) > 0 {
updateMax()
x := p.Get()
updateMax()
time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
updateMax()
p.Put(x)
updateMax()
}
}()
}
wg.Wait()
if max != p.max {
t.Errorf("Actual maximum count (%d) != ideal maximum count (%d)", max, p.max)
}
}
func BenchmarkWaitPool(b *testing.B) {
var wg sync.WaitGroup
trials := int32(b.N)
workers := runtime.NumCPU() + 2
if workers-4 <= 0 {
b.Skip("Not enough cores")
}
p := NewWaitPool(uint32(workers-4), func() interface{} { return make([]byte, 16) })
wg.Add(workers)
b.ResetTimer()
for i := 0; i < workers; i++ {
go func() {
defer wg.Done()
for atomic.AddInt32(&trials, -1) > 0 {
x := p.Get()
time.Sleep(time.Duration(rand.Intn(100)) * time.Microsecond)
p.Put(x)
}
}()
}
wg.Wait()
}