Performance cost of starting isolates in parallel

v8_startup_parallelism.go

package main

import (
	"fmt"
	"runtime"
	"sync"
	"time"

	v8 "rogchap.com/v8go"
)

func startIsolatesInParallel(n int) {
	start := time.Now()
	var wg sync.WaitGroup
	for i := 0; i < n; i++ {
		wg.Add(1)
		go func() {
			runtime.LockOSThread()
			defer runtime.UnlockOSThread()
			isolate := v8.NewIsolate()
			defer isolate.Dispose()
			v8.NewContext(isolate)
			wg.Done()
		}()
	}

	wg.Wait()
	fmt.Println(n, ":", time.Since(start))
}

func main() {
	var start time.Time
	start = time.Now()
	isolate := v8.NewIsolate()
	v8.NewContext(isolate)
	isolate.Dispose()
	fmt.Println("Warmup:", time.Since(start))
	startIsolatesInParallel(1)
	startIsolatesInParallel(1)
	startIsolatesInParallel(2)
	startIsolatesInParallel(2)
	startIsolatesInParallel(4)
	startIsolatesInParallel(4)
	startIsolatesInParallel(10)
}

// Warmup: 8.218875ms
// 1 : 1.521208ms
// 1 : 1.216208ms
// 2 : 1.378416ms
// 2 : 1.241666ms
// 4 : 1.676334ms
// 4 : 2.10425ms
// 10 : 5.307583ms