shmat help

airsupply airsupply at freebsdchina.org
Sun Feb 8 05:26:25 PST 2004


airsupply,=C4=FA=BA=C3=A3=A1

=09oh,i have get it. it's code error.

=3D=3D=3D=3D=3D=3D=3D 2004-02-07 23:37:00 =C4=FA=D4=DA=C0=B4=D0=C5=D6=D0=D0=B4=B5=C0=A3=BA=3D=3D=3D=3D=3D=3D=3D

>freebsd-hackers=A3=AC=C4=FA=BA=C3=A3=A1
>
>=09                  
>i am test shmat under freebsd 4.8 release(without undate),but a=
 piece of simple code wont work.
>code like this:
>#include<stdio.h>
>#include<machine/param.h>
>#include<sys/types.h>
>#include<sys/ipc.h>
>#include<sys/shm.h>
>#include <unistd.h>
>
>#define SHM_KEY 100
>#define SHM_SIZE 1024
>int main(int argc,char *argv[])
>{
>        int shmid;
>        void *shmaddr1,*shmaddr2,*shmaddr3;
>        if(shmid=3Dshmget(SHM_KEY,SHM_SIZE,IPC_CREAT|0660)=3D=3D-1)
>        {
>                perror("shmget");
>                exit(-1);
>        }
>
>        printf("shmid: d\n",shmid);
>        if(shmaddr1=3Dshmat(shmid,0,0)=3D=3D-1)
>        {
>                perror("shmat 1");
>                exit(-1);
>        }
>        printf("shaddr1:0x.8x\n",shmaddr1);
>
>        if(shmaddr2=3Dshmat(shmid,0,0)=3D=3D-1)
>        {
>                perror("shmat 2");
>                exit(-1);
>        }
>        printf("shaddr2:0x.8x\n",shmaddr2);
>        while(1);
>        return 0;
>}
>
>then i get error like this:
>
>shmid: 0
>shmat 1: Invalid argument
>then i use ipcs,find that the shmid is not 0,but an integer=
 number.
>-bash-2.05b$ ipcs
>Message Queues:
>T     ID     KEY        MODE       OWNER    GROUP
>
>Shared Memory:
>T     ID     KEY        MODE       OWNER    GROUP
>m  65536        100 --rw-rw-rw-     airs    wheel
>
>Semaphores:
>T     ID     KEY        MODE       OWNER    GROUP
>
>
>
>who can help me? who i can't use the shmid at shmat(shmid,0,0) ?=
  
>
>
>=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=D6=C2
>=C0=F1=A3=A1
> =09=09=09=09
>
>=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1airsupply
>=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1airsupply at freebsdchina.org
>=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A12004-02-07
>
>
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=3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D =3D
=09=09=09

=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=D6=C2
=C0=F1=A3=A1
 
=09=09=09=09 
=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1airsupply
=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1airsupply at freebsdchina.org
=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A1=A12004-02-08





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