root/include/linux/msg.h

/* */

INCLUDED FROM

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

/* */