Question

我编写了一个小C代码，它存在一个变量作为int指针。进程应该做的是减去该变量的值，直到它达到0。问题是，即使程序打印的地址相同，每个进程似乎都有自己的变量副本。是否会发生这种情况，因为每个进程在内存中都有自己的空间？

这是输出：

START
Account address: 0x7ffee5820be0
Parent substracted 10. Account value: 90, address 0x7ffee5820be0
Parent substracted 10. Account value: 80, address 0x7ffee5820be0
Parent substracted 10. Account value: 70, address 0x7ffee5820be0
Parent substracted 10. Account value: 60, address 0x7ffee5820be0
Parent substracted 10. Account value: 50, address 0x7ffee5820be0
Parent substracted 10. Account value: 40, address 0x7ffee5820be0
Parent substracted 10. Account value: 30, address 0x7ffee5820be0
Parent substracted 10. Account value: 20, address 0x7ffee5820be0
Parent substracted 10. Account value: 10, address 0x7ffee5820be0
Parent substracted 10. Account value: 0, address 0x7ffee5820be0
Child substracted 10. Account value: 90 , address 0x7ffee5820be0
Child substracted 10. Account value: 80 , address 0x7ffee5820be0
Child substracted 10. Account value: 70 , address 0x7ffee5820be0
Child substracted 10. Account value: 60 , address 0x7ffee5820be0
Child substracted 10. Account value: 50 , address 0x7ffee5820be0
Child substracted 10. Account value: 40 , address 0x7ffee5820be0
Child substracted 10. Account value: 30 , address 0x7ffee5820be0
Child substracted 10. Account value: 20 , address 0x7ffee5820be0
Child substracted 10. Account value: 10 , address 0x7ffee5820be0
Child substracted 10. Account value: 0 , address 0x7ffee5820be0

Answer 1

是的，你的假设是正确的。

如果您想共享内存空间，可以选择以下几种方法：

要么查看共享内存 - ＆＃34; POSIX共享内存＆＃34; 或＆＃34; System V共享内存＆＃34; ，或
使用线程 - C11 / C ++ 11线程或＆＃34; pthreads＆＃34; （即POSIX线程） - 自动共享相同的内存空间，或
使用 Redis ，这是一个非常快速的内存数据结构服务器（队列，列表，集合，哈希，字符串/整数/浮点数）然后你可以共享变量（实际上是原子的）世界各地的进程之间。

Answer 2

查看这篇文章，我认为它将解释为什么父母和孩子的地址似乎相同，以及父母和孩子之间不共享整个记忆状态的事实：

fork() system call and memory space of the process

并行进程不共享相同的数据

2 个答案: