C语言：

[root@localhost efficient]# cat calc_c.c#include<stdio.h>#include<time.h>int main(char贪玩的裙子 argv, char argc){ int second1,second2; long long i; long long count; second1 = time((time_t*)NULL); count = 0; for (i = 0 ; i < 9000000000ll; i++){ count += i; } second2 = time((time_t*)NULL); printf("cost:%d,count:%lld\n", second2 - second1, count); return 0;}[root@localhost efficient]# make calc_ccc calc_c.c -o calc_c[root@localhost efficient]# ./calc_ccost:57,count:3606511848080896768

golang：

[root@localhost efficient]# cat calc_go.gopackage mainimport "fmt"import "time"func main(){ t1 := time.Now() count :=int64(0) max := int64(9000000000) for i :=int64(0); i< max; i++{ count += i } t2 := time.Now() fmt.Printf("cost:%d,count:%d\n",t2.Sub(t1)/1000000000,count)}[root@localhost efficient]# go build calc_go.go[root@localhost efficient]# ./calc_gocost:52,count:3606511848080896768

基本一致，c用时57s，go用时52s。

下面加入简单Coroutine尝试

[root@localhost efficient]# cat calc_coroutine.gopackage mainimport "fmt"import "runtime"import "time"func run(i,n int64 ,ch chan int64){ count := int64(0) for i := int64(i); i < n; i++ { count = count +i } ch <- count}func main(){ t1 := time.Now() NCPU := runtime.NumCPU() fmt.Printf("NCPU:%d\n",NCPU) runtime.GOMAXPROCS(NCPU) chs := make([] chan int64,NCPU) for i :=int64(0); i < int64(NCPU); i++{ chs[i] = make(chan int64) n := int64(9000000000)/int64(NCPU) go run(i*n, (i+1)*n,chs[i]) } count := int64(0) for i :=0; i < NCPU;i++{ t := <- chs[i] count = count +t } t2 := time.Now() fmt.Printf("cpu num:%d,cost:%d,count:%d\n",NCPU,t2.Sub(t1)/1000000000,count)}[root@localhost efficient]# go build calc_coroutine.go[root@localhost efficient]# ./calc_coroutineNCPU:2cpu num:2,cost:34,count:3606511848080896768

用时34s，确实提高了，关键是实现很简单