msg.h

Go to the documentation of this file.

#ifndef _LINUX_MSG_H
#define _LINUX_MSG_H

#include <linux/list.h>
#include <uapi/linux/msg.h>

/* one msg_msg structure for each message */
struct msg_msg {
    struct list_head m_list; 
    long  m_type;          
    int m_ts;           /* message text size */
    struct msg_msgseg* next;
    void *security;
    /* the actual message follows immediately */
};

/* one msq_queue structure for each present queue on the system */
struct msg_queue {
    struct kern_ipc_perm q_perm;
    time_t q_stime;         /* last msgsnd time */
    time_t q_rtime;         /* last msgrcv time */
    time_t q_ctime;         /* last change time */
    unsigned long q_cbytes;     /* current number of bytes on queue */
    unsigned long q_qnum;       /* number of messages in queue */
    unsigned long q_qbytes;     /* max number of bytes on queue */
    pid_t q_lspid;          /* pid of last msgsnd */
    pid_t q_lrpid;          /* last receive pid */

    struct list_head q_messages;
    struct list_head q_receivers;
    struct list_head q_senders;
};

/* Helper routines for sys_msgsnd and sys_msgrcv */
extern long do_msgsnd(int msqid, long mtype, void __user *mtext,
            size_t msgsz, int msgflg);
extern long do_msgrcv(int msqid, long *pmtype, void __user *mtext,
            size_t msgsz, long msgtyp, int msgflg);

#endif /* _LINUX_MSG_H */