include/linux/msg.h

   1 #ifndef _LINUX_MSG_H
   2 #define _LINUX_MSG_H
   3
   4 #include <linux/ipc.h>
   5
   6 /* ipcs ctl commands */
   7 #define MSG_STAT 11
   8 #define MSG_INFO 12
   9
  10 /* msgrcv options */
  11 #define MSG_NOERROR     010000  /* no error if message is too big */
  12 #define MSG_EXCEPT      020000  /* recv any msg except of specified type.*/
  13
  14 /* one msqid structure for each queue on the system */
  15 struct msqid_ds {
  16         struct ipc_perm msg_perm;
  17         struct msg *msg_first;          /* first message on queue */
  18         struct msg *msg_last;           /* last message in queue */
  19         __kernel_time_t msg_stime;      /* last msgsnd time */
  20         __kernel_time_t msg_rtime;      /* last msgrcv time */
  21         __kernel_time_t msg_ctime;      /* last change time */
  22         wait_queue_head_t wwait;
  23         wait_queue_head_t rwait;
  24         unsigned short msg_cbytes;      /* current number of bytes on queue */
  25         unsigned short msg_qnum;        /* number of messages in queue */
  26         unsigned short msg_qbytes;      /* max number of bytes on queue */
  27         __kernel_ipc_pid_t msg_lspid;   /* pid of last msgsnd */
  28         __kernel_ipc_pid_t msg_lrpid;   /* last receive pid */
  29 };
  30
  31 /* message buffer for msgsnd and msgrcv calls */
  32 struct msgbuf {
  33         long mtype;         /* type of message */
  34         char mtext[1];      /* message text */
  35 };
  36
  37 /* buffer for msgctl calls IPC_INFO, MSG_INFO */
  38 struct msginfo {
  39         int msgpool;
  40         int msgmap;
  41         int msgmax;
  42         int msgmnb;
  43         int msgmni;
  44         int msgssz;
  45         int msgtql;
  46         unsigned short  msgseg;
  47 };
  48
  49 #define MSGMNI   128   /* <= 1K */     /* max # of msg queue identifiers */
  50 #define MSGMAX  4056   /* <= 4056 */   /* max size of message (bytes) */
  51 #define MSGMNB 16384   /* ? */        /* default max size of a message queue */
  52
  53 /* unused */
  54 #define MSGPOOL (MSGMNI*MSGMNB/1024)  /* size in kilobytes of message pool */
  55 #define MSGTQL  MSGMNB            /* number of system message headers */
  56 #define MSGMAP  MSGMNB            /* number of entries in message map */
  57 #define MSGSSZ  16                /* message segment size */
  58 #define __MSGSEG ((MSGPOOL*1024)/ MSGSSZ) /* max no. of segments */
  59 #define MSGSEG (__MSGSEG <= 0xffff ? __MSGSEG : 0xffff)
  60
  61 #ifdef __KERNEL__
  62
  63 /* one msg structure for each message */
  64 struct msg {
  65         struct msg *msg_next;   /* next message on queue */
  66         long  msg_type;
  67         char *msg_spot;         /* message text address */
  68         time_t msg_stime;       /* msgsnd time */
  69         short msg_ts;           /* message text size */
  70 };
  71
  72 asmlinkage int sys_msgget (key_t key, int msgflg);
  73 asmlinkage int sys_msgsnd (int msqid, struct msgbuf *msgp, size_t msgsz, int msgflg);
  74 asmlinkage int sys_msgrcv (int msqid, struct msgbuf *msgp, size_t msgsz, long msgtyp,
  75                        int msgflg);
  76 asmlinkage int sys_msgctl (int msqid, int cmd, struct msqid_ds *buf);
  77
  78 #endif /* __KERNEL__ */
  79
  80 #endif /* _LINUX_MSG_H */