sys/sys/mqueue.h

   1 /*      $NetBSD: mqueue.h,v 1.17 2015/06/20 14:41:54 martin Exp $       */
   2
   3 /*
   4  * Copyright (c) 2007-2009 Mindaugas Rasiukevicius <rmind at NetBSD org>
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #ifndef _SYS_MQUEUE_H_
  30 #define _SYS_MQUEUE_H_
  31
  32 /* Maximal number of mqueue descriptors, that process could open */
  33 #define MQ_OPEN_MAX             512
  34
  35 /* Maximal priority of the message */
  36 #define MQ_PRIO_MAX             32
  37
  38 struct mq_attr {
  39         long    mq_flags;       /* Flags of message queue */
  40         long    mq_maxmsg;      /* Maximum number of messages */
  41         long    mq_msgsize;     /* Maximum size of the message */
  42         long    mq_curmsgs;     /* Count of the queued messages */
  43 };
  44
  45 /* Internal kernel data */
  46 #ifdef _KERNEL
  47
  48 #include <sys/condvar.h>
  49 #include <sys/mutex.h>
  50 #include <sys/queue.h>
  51 #include <sys/selinfo.h>
  52 #include <sys/types.h>
  53 #include <sys/param.h>
  54
  55 /*
  56  * Flags below are used in mq_flags for internal purposes.
  57  * This is permitted according to POSIX.
  58  */
  59
  60 /* Message queue is unlinked */
  61 #define MQ_UNLINKED             0x10000000
  62 /* There are receive-waiters */
  63 #define MQ_RECEIVE              0x20000000
  64
  65 /* Maximal length of mqueue name */
  66 #define MQ_NAMELEN              (KERNEL_NAME_MAX + 1)
  67
  68 /* Default size of the message */
  69 #define MQ_DEF_MSGSIZE          1024
  70
  71 /* Size/bits and index of reserved queue */
  72 #define MQ_PQSIZE               32
  73 #define MQ_PQRESQ               0
  74
  75 /* Structure of the message queue. */
  76 typedef struct mqueue {
  77         char *                  mq_name;
  78         kmutex_t                mq_mtx;
  79         kcondvar_t              mq_send_cv;
  80         kcondvar_t              mq_recv_cv;
  81         struct mq_attr          mq_attrib;
  82         /* Notification */
  83         struct selinfo          mq_rsel;
  84         struct selinfo          mq_wsel;
  85         struct sigevent         mq_sig_notify;
  86         struct proc *           mq_notify_proc;
  87         /* Permissions */
  88         mode_t                  mq_mode;
  89         uid_t                   mq_euid;
  90         gid_t                   mq_egid;
  91         /* Reference counter, queue array and bitmap */
  92         u_int                   mq_refcnt;
  93         TAILQ_HEAD(, mq_msg)    mq_head[1 + MQ_PQSIZE];
  94         uint32_t                mq_bitmap;
  95         /* Entry of the global list */
  96         LIST_ENTRY(mqueue)      mq_list;
  97         /* Time stamps */
  98         struct timespec         mq_atime;
  99         struct timespec         mq_mtime;
 100         struct timespec         mq_btime;
 101 } mqueue_t;
 102
 103 /* Structure of the message. */
 104 typedef struct mq_msg {
 105         TAILQ_ENTRY(mq_msg)     msg_queue;
 106         size_t                  msg_len;
 107         u_int                   msg_prio;
 108         uint8_t                 msg_ptr[1];
 109 } mq_msg_t;
 110
 111 /* Prototypes */
 112 void    mqueue_print_list(void (*pr)(const char *, ...) __printflike(1, 2));
 113 int     mq_send1(mqd_t, const char *, size_t, u_int, struct timespec *);
 114 int     mq_recv1(mqd_t, void *, size_t, u_int *, struct timespec *, ssize_t *);
 115 int     mqueue_get(mqd_t mqd, int fflag, mqueue_t **mqret);
 116 int     mq_handle_open(struct lwp *l, const char *, int, mode_t,
 117             struct mq_attr*, register_t *retval);
 118
 119 #endif  /* _KERNEL */
 120
 121 #endif  /* _SYS_MQUEUE_H_ */