ipcmsgbuf
msgsnd(int msqid, struct ipcmsgbuf *msgp, size_t msgsz, int msgflg)
STRUCT_HANDLE(ipcmsgbuf, umsgp);
error = msgrcv((int)a1, (struct ipcmsgbuf *)a2,
error = msgsnd((int)a1, (struct ipcmsgbuf *)a2,
error = msgrcv((int)a1, (struct ipcmsgbuf *)(uintptr_t)a2,
error = msgsnd((int)a1, (struct ipcmsgbuf *)(uintptr_t)a2,
struct msg *, struct ipcmsgbuf *, int);
msgrcv(int msqid, struct ipcmsgbuf *msgp, size_t msgsz, long msgtyp, int msgflg)
size_t msgsz, struct msg *smp, struct ipcmsgbuf *msgp, int msgflg)
STRUCT_HANDLE(ipcmsgbuf, umsgp);