1struct msqid_ds {
2    struct ipc_perm msg_perm;
3    time_t msg_stime;
4    time_t msg_rtime;
5    time_t msg_ctime;
6    unsigned long msg_cbytes;
7    msgqnum_t msg_qnum;
8    msglen_t msg_qbytes;
9    pid_t msg_lspid;
10    pid_t msg_lrpid;
11    unsigned long __unused[2];
12};
13