问题描述

linux vfork 进程的结果出现奇怪的问题

 #include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <unistd.h>

int globVar = 5;

int main (void)
{
    pid_t pid;
    int var = 1, i;

    printf("fork is different with vforkn ");
//  pid = fork();
    pid = vfork();
    switch(pid){
        case 0:
            i = 3;
            while(i-- > 0)
            {
                printf("child process is running!n");
                globVar++;
                var++;
            }
            printf("%d, %dn",globVar,var);
        break;
        case 1:
            perror("process creation failed!n");

        exit(0);
        default:
            i = 5;
            while(i-- > 0)
            {
                printf("parent process is runningn");
                globVar++;
                var++;
                sleep(1);
            }
            printf("%d, %dn",globVar,var);
            exit(0);
    }   

}

结果

[root@localhost labtwo]# ./diffork
fork is different with vfork
 child process is running!
child process is running!
child process is running!
8,      4
parent process is running
parent process is running
parent process is running
parent process is running
parent process is running
13,     11345274

最后的父进程var的值不应该是9吗怎么会是11345274 谁能帮忙解一下疑惑？谢谢了

解决方案

    T.T你们都不理我

解决方案二：

首先失败应该返回-1, 然后父进程的var应该是没有初始化