多线程简单测试(输出500000000个数字)

C++代码如下：

 

#include<stdio.h>
#include<stdlib.h>
#include<pthread.h>
#include<unistd.h>
//线程的最大数量
const int THREAD_MAX_NUM = 100;
pthread_t threads[THREAD_MAX_NUM];
//线程的编号
int thread_mark[THREAD_MAX_NUM];
//平均每个线程需要打印数字的个数
int avg_num;
//线程数
int pthread_num = 1;
//数字的数目
int number_num = 1;
/*
 * 输出数字的线程函数
 */
void * output_number (void * arg){
        int thread_id = *((int*)arg);
        printf("thread_id: %d\n", thread_id);
        //计算线程输出的数字的范围
        int st = 0, ed = 1;
        st = thread_id*avg_num;
        if(thread_id == pthread_num - 1){
                ed = number_num;
        }else{
                ed = st + avg_num;
        }
        char fname[32];
        sprintf(fname, "/tmp/pthread/%d.log", thread_id);
        FILE* fp = fopen(fname, "w+");
        for(int i = st; i < ed; i++){
                //printf("%d\n", i);
                fprintf(fp, "%d\n", i);
        }
        return NULL;
}
int main(int argc, char* argv[]){
        int opt;
        while((opt=getopt(argc, argv,"p:n:h"))!=-1){
                switch(opt){
                        case 'p':
                                pthread_num = atoi(optarg);
                                break;
                        case 'n':
                                number_num = atoi(optarg);
                                break;
                }
        }
        if(pthread_num < 1){
                pthread_num = 1;
        }
        if(number_num < 1){
                number_num = 1;
        }
        avg_num = number_num / pthread_num; 
        printf("pthread_num: %d\n", pthread_num);
        for(int i = 0; i < pthread_num; i++){
                thread_mark[i] = i;
                pthread_create(threads+i, NULL, output_number, thread_mark+i);
        }
        for(int i = 0; i < pthread_num; i++){
                pthread_join(threads[i], NULL);
        }
        //sleep(2);
        return 0;
}

 测试情况如下：

 

	1个线程(单位:秒)	6个线程(单位:秒)	12个线程(单位:秒)	15个线程(单位:秒)	16个线程(单位:秒)
均值	73.351	11.9015	9.0455	7.604	7.5105
	71.166	11.818	8.388	8.079	8.482
	74.6	12.078	16.865	6.898	8.702
	72.26	12.27	8.478	6.749	11.197
	73.475	11.954	7.087	6.895	7.547
	75.536	11.985	9.703	7.129	6.539