map_anoy.c

来自「关于进程间通信的代码集锦2」· C语言 代码 · 共 42 行

#include <sys/mman.h>
#include <sys/types.h>
#include <fcntl.h>
#include <unistd.h>
typedef struct{
	char name[4];
	int age;
}people;

int main(int argc,char** argv)
{
	int i;
	people* p_map;
	char temp;
	p_map=(people*)mmap(NULL,sizeof(people)*10,PROT_READ|PROT_WRITE,MAP_SHARED|MAP_ANONYMOUS,-1,0);
	if(fork()==0)
	{
		sleep(2);
		for(i=0;i<5;i++)
		{
			printf("child read: the %d people's age is %d\n",i+1,(*(p_map+i)).age);
		}
		(*p_map).age=100;
		munmap(p_map,sizeof(people)*10);
		exit(0);		
	}
	temp='a';
	for(i=0;i<5;i++)
	{
		temp+1;
		memcpy((*(p_map+i)).name,&temp,2);
		(*(p_map+i)).age=20+i;
	}
	sleep(5);
	printf("parent read:the first people's age is %d\n",(*p_map).age);
	printf("umap\n");
	munmap(p_map,sizeof(people)*10);
	printf("umap ok\n");

	return 0;
}