1 /* $NetBSD: mqueue.h,v 1.7 2009/04/11 15:47:34 christos Exp $ */ 2 3 /* 4 * Copyright (c) 2007, 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 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES) 47 48 #include <sys/types.h> 49 #include <sys/lock.h> 50 #include <sys/queue.h> 51 #include <sys/event.h> 52 #include <sys/signal.h> 53 54 /* 55 * Flags below are used in mq_flags for internal 56 * purposes, this is appropriate according to POSIX. 57 */ 58 59 /* Message queue is unlinking */ 60 #define MQ_UNLINK 0x10000000 61 /* There are receive-waiters */ 62 #define MQ_RECEIVE 0x20000000 63 64 /* Maximal length of mqueue name */ 65 #define MQ_NAMELEN (NAME_MAX + 1) 66 67 /* Default size of the message */ 68 #define MQ_DEF_MSGSIZE 1024 69 70 /* Size/bits and index of reserved queue */ 71 #define MQ_PQSIZE 32 72 #define MQ_PQRESQ 0 73 74 /* Structure of the message queue */ 75 struct mqueue { 76 char mq_name[MQ_NAMELEN]; 77 struct lock mq_mtx; 78 int mq_send_cv; /* Condition variables for tsleep() */ 79 int mq_recv_cv; 80 struct mq_attr mq_attrib; 81 /* Notification */ 82 struct kqinfo mq_rkq; 83 struct kqinfo mq_wkq; 84 struct sigevent mq_sig_notify; 85 struct proc * mq_notify_proc; 86 /* Permissions */ 87 mode_t mq_mode; 88 uid_t mq_euid; 89 gid_t mq_egid; 90 /* 91 * Reference counter, heads of the message queue 92 * 93 * Every message queue has `MQ_PQSIZE' priority queues that guarantee 94 * constant-time insertion of messages. If `mq_prio_max' is increased 95 * via sysctl, then the reserved queue (MQ_PQRESQ) is used which 96 * performs linear insertion. 97 */ 98 u_int mq_refcnt; 99 TAILQ_HEAD(, mq_msg) mq_head[1 + MQ_PQSIZE]; 100 uint32_t mq_bitmap; 101 /* Entry of the global list */ 102 LIST_ENTRY(mqueue) mq_list; 103 struct timespec mq_atime; 104 struct timespec mq_mtime; 105 struct timespec mq_btime; 106 }; 107 108 /* Structure of the message */ 109 struct mq_msg { 110 TAILQ_ENTRY(mq_msg) msg_queue; 111 size_t msg_len; 112 u_int msg_prio; 113 int8_t msg_ptr[1]; 114 }; 115 116 /* Prototypes */ 117 void mqueue_sysinit(void); 118 int abstimeout2timo(struct timespec *, int *); 119 int mq_send1(struct lwp *, mqd_t, const char *, size_t, unsigned, struct timespec *); 120 int mq_receive1(struct lwp *, mqd_t, void *, size_t, unsigned *, struct timespec *, 121 ssize_t *); 122 123 #endif /* _KERNEL || _KERNEL_STRUCTURES */ 124 125 #endif /* _SYS_MQUEUE_H_ */ 126 127