msgbuf.h

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#ifndef __ASM_GENERIC_MSGBUF_H
#define __ASM_GENERIC_MSGBUF_H

#include <asm/bitsperlong.h>
/*
 * generic msqid64_ds structure.
 *
 * Note extra padding because this structure is passed back and forth
 * between kernel and user space.
 *
 * msqid64_ds was originally meant to be architecture specific, but
 * everyone just ended up making identical copies without specific
 * optimizations, so we may just as well all use the same one.
 *
 * 64 bit architectures typically define a 64 bit __kernel_time_t,
 * so they do not need the first three padding words.
 * On big-endian systems, the padding is in the wrong place.
 *
 * Pad space is left for:
 * - 64-bit time_t to solve y2038 problem
 * - 2 miscellaneous 32-bit values
 */

struct msqid64_ds {
    struct ipc64_perm msg_perm;
    __kernel_time_t msg_stime;  /* last msgsnd time */
#if __BITS_PER_LONG != 64
    unsigned long   __unused1;
#endif
    __kernel_time_t msg_rtime;  /* last msgrcv time */
#if __BITS_PER_LONG != 64
    unsigned long   __unused2;
#endif
    __kernel_time_t msg_ctime;  /* last change time */
#if __BITS_PER_LONG != 64
    unsigned long   __unused3;
#endif
    unsigned long  msg_cbytes;  /* current number of bytes on queue */
    unsigned long  msg_qnum;    /* number of messages in queue */
    unsigned long  msg_qbytes;  /* max number of bytes on queue */
    __kernel_pid_t msg_lspid;   /* pid of last msgsnd */
    __kernel_pid_t msg_lrpid;   /* last receive pid */
    unsigned long  __unused4;
    unsigned long  __unused5;
};

#endif /* __ASM_GENERIC_MSGBUF_H */