回頁首if(fd<0)
...回頁首
#include #include #include #include typedef structpeople;
main(int argc, char** argv) // map a normal file as shared mem:
printf(" initialize over /n ")；
sleep(10);
munmap( p_map, sizeof(people)*10 );
printf( "umap ok /n" );
}/*-------------map_normalfile2.c-----------*/
#include #include #include #include typedef structpeople;
main(int argc, char** argv) // map a normal file as shared mem:
munmap( p_map,sizeof(people)*10 );
}umap ok
name: g age 25; name: h age 26; name: i age 27; name: j age 28; name: k age 29;
name: age 0; name: age 0; name: age 0; name: age 0; name: age 0;
char name[4];
int age;
}people;
main(int argc, char** argv)
temp = 'a';
for(i = 0;i<5;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" );
}child read: the 2 people's age is 21
child read: the 3 people's age is 22
child read: the 4 people's age is 23
child read: the 5 people's age is 24
parent read: the first people,s age is 100
umap
umap ok
回頁首 char name[4];
int age;
}people;
main(int argc, char** argv)
munmap(p_map,sizeof(people)*10);
}access page 1 over
access page 1 edge over, now begin to access page 2
access page 2 over
access page 2 over
access page 2 edge over, now begin to access page 3
bus error //被對映檔案在程序空間中覆蓋了兩個頁面，此時，程序試圖訪問第三個頁面
access page 1 over
access page 1 edge over, now begin to access page 2
bus error //被對映檔案在程序空間中覆蓋了乙個頁面，此時，程序試圖訪問第二個頁面
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