include/linux/msg.h

15849 #ifndef _LINUX_MSG_H
15850 #define _LINUX_MSG_H
15851 
15852 #include <linux/ipc.h>
15853 
15854 /* ipcs ctl commands */
15855 #define MSG_STAT 11
15856 #define MSG_INFO 12
15857 
15858 /* msgrcv options */
15859 /* no error if message is too big */
15860 #define MSG_NOERROR 010000
15861   /* recv any msg except of specified type.*/
15862 #define MSG_EXCEPT  020000
15863 
15864 /* one msqid structure for each queue on the system */
15865 struct msqid_ds {
15866   struct ipc_perm msg_perm;
15867   struct msg *msg_first;        /* first msg on queue */
15868   struct msg *msg_last;         /* last msg in queue */
15869   __kernel_time_t msg_stime;    /* last msgsnd time */
15870   __kernel_time_t msg_rtime;    /* last msgrcv time */
15871   __kernel_time_t msg_ctime;    /* last change time */
15872   struct wait_queue *wwait;
15873   struct wait_queue *rwait;
15874   unsigned short msg_cbytes;    /* current # bytes on q*/
15875   unsigned short msg_qnum;      /* # of msgs in queue */
15876   unsigned short msg_qbytes;    /* max # of bytes on q */
15877   __kernel_ipc_pid_t msg_lspid; /* pid of last msgsnd */
15878   __kernel_ipc_pid_t msg_lrpid; /* last receive pid */
15879 };
15880 
15881 /* message buffer for msgsnd and msgrcv calls */
15882 struct msgbuf {
15883   long mtype;         /* type of message */
15884   char mtext[1];      /* message text */
15885 };
15886 
15887 /* buffer for msgctl calls IPC_INFO, MSG_INFO */
15888 struct msginfo {
15889   int msgpool;
15890   int msgmap;
15891   int msgmax;
15892   int msgmnb;
15893   int msgmni;
15894   int msgssz;
15895   int msgtql;
15896   unsigned short  msgseg;
15897 };
15898 
15899 /* max # of msg queue identifiers */
15900 #define MSGMNI   128   /* <= 1K */
15901 /* max size of message (bytes) */
15902 #define MSGMAX  4056   /* <= 4056 */
15903 /* default max size of a message queue */
15904 #define MSGMNB 16384   /* ? */
15905 
15906 /* unused */
15907 /* size in kilobytes of message pool */
15908 #define MSGPOOL (MSGMNI*MSGMNB/1024)
15909 #define MSGTQL  MSGMNB /* number of system msg headers */
15910 #define MSGMAP  MSGMNB /* number of entries in msg map */
15911 #define MSGSSZ  16     /* message segment size */
15912 /* max no. of segments */
15913 #define __MSGSEG ((MSGPOOL*1024)/ MSGSSZ)
15914 #define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
15915 
15916 #ifdef __KERNEL__
15917 
15918 /* one msg structure for each message */
15919 struct msg {
15920   struct msg *msg_next;   /* next message on queue */
15921   long  msg_type;
15922   char *msg_spot;         /* message text address */
15923   time_t msg_stime;       /* msgsnd time */
15924   short msg_ts;           /* message text size */
15925 };
15926 
15927 asmlinkage int sys_msgget(key_t key, int msgflg);
15928 asmlinkage int sys_msgsnd(int msqid, struct msgbuf *msgp,
15929                           size_t msgsz, int msgflg);
15930 asmlinkage int sys_msgrcv(int msqid, struct msgbuf *msgp,
15931                           size_t msgsz, long msgtyp,
15932                           int msgflg);
15933 asmlinkage int sys_msgctl(int msqid, int cmd,
15934                           struct msqid_ds *buf);
15935 
15936 #endif /* __KERNEL__ */
15937 
15938 #endif /* _LINUX_MSG_H */