Home | History | Annotate | Line # | Download | only in sys 
      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_ */
    122