sumint_single_thread.c

/*************************************************************************
    > File Name: sumint.c
  > Author: perrynzhou
  > Mail: perrynzhou@gmail.com
  > Created Time: Sun 04 Mar 2018 02:51:53 AM EST
 ************************************************************************/

#include <stdio.h>
#include <stdint.h>
#include <pthread.h>
#include <stdlib.h>
typedef struct {
    uint64_t data;
    int count;
} value;
void add(value* v)
{
    for (int i = 0; i < v->count; i++) {
        __sync_fetch_and_add(&v->data, 1);
    }
}
int main(int argc, char* argv[])
{
    int num = atoi(argv[1]);
    pthread_t thds[num];
    value v = {
        .data = 0,
        .count = atoi(argv[2])
    };
    add(&v);
    fprintf(stdout, "running %d thread,&value{data=%ld,count=%d}n", num, v.data, v.count);
    return 0;
}

sumint_multi_thread.c

#include <stdio.h>
#include <stdint.h>
#include <pthread.h>
#include <stdlib.h>
typedef struct {
    uint64_t data;
    int count;
} value;
void add(value* v)
{
    for (int i = 0; i < v->count; i++) {
        __sync_fetch_and_add(&v->data, 1);
    }
}
int main(int argc, char* argv[])
{
    int num = atoi(argv[1]);
    pthread_t thds[num];
    value v = {
        .data = 0,
        .count = atoi(argv[2])
    };
    for (int i = 0; i < num; i++) {
        pthread_create(&thds[i], NULL, (void*)&add, (void*)&v);
    }
    for (int i = 0; i < num; i++) {
        pthread_join(thds[i], NULL);
    }
    fprintf(stdout, "running %d thread,&value{data=%ld,count=%d}n", num, v.data, v.count);
    return 0;
}

sumint.go

package main

import (
    "flag"
    "fmt"
    "sync"
    "sync/atomic"
)

func main() {
    count := flag.Int64("count", 10000, "count")
    thread := flag.Int("thread", 1, "thread")
    flag.Parse()
    var data uint64
    var wg sync.WaitGroup
    wg.Add(*thread)
    for i := 0; i < *thread; i++ {
        go func(d *uint64, wg *sync.WaitGroup) {
            var i int64
            defer wg.Done()
            for i = 0; i < *count; i++ {
                atomic.AddUint64(d, 1)
            }
        }(&data, &wg)
    }
    wg.Wait()
    fmt.Printf("running %d goroutine ,&Value{data=%v,count=%v}n", *thread, data, *count)
}

test.sh

$ cat test.sh
#!/bin/bash
echo "-----c_sumint_single_test-----"
time ./c_sumint_single_test 1 20000000
echo "-----c_sumint_multi_test----"
time ./c_sumint_multi_test 20 1000000
echo "-----go_sumint_nulti_test----"
time ./go_sumint_test -thread=20 -count=1000000

性能测试结果

Jietu20180304-170107@2x.jpg

总结

1.linux 下pthread的性能开销确实比golang 的goroutine开销大,毕竟goroutine是running在pthread之上的，是在线程上实现的多并发，上下文切换远比线程切换小。
2.linux下单线程的性能远比多个goroutine的性能好，少了很多的性能开销。
3.在不同的场景下使用不同的programming tools解决不同的问题。