mqueue.h (2201B)
1/* SPDX-License-Identifier: LGPL-2.1+ WITH Linux-syscall-note */ 2/* Copyright (C) 2003 Krzysztof Benedyczak & Michal Wronski 3 4 This program is free software; you can redistribute it and/or 5 modify it under the terms of the GNU Lesser General Public 6 License as published by the Free Software Foundation; either 7 version 2.1 of the License, or (at your option) any later version. 8 9 It is distributed in the hope that it will be useful, 10 but WITHOUT ANY WARRANTY; without even the implied warranty of 11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 Lesser General Public License for more details. 13 14 You should have received a copy of the GNU Lesser General Public 15 License along with this software; if not, write to the Free 16 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 17 02111-1307 USA. */ 18 19#ifndef _LINUX_MQUEUE_H 20#define _LINUX_MQUEUE_H 21 22#include <linux/types.h> 23 24#define MQ_PRIO_MAX 32768 25/* per-uid limit of kernel memory used by mqueue, in bytes */ 26#define MQ_BYTES_MAX 819200 27 28struct mq_attr { 29 __kernel_long_t mq_flags; /* message queue flags */ 30 __kernel_long_t mq_maxmsg; /* maximum number of messages */ 31 __kernel_long_t mq_msgsize; /* maximum message size */ 32 __kernel_long_t mq_curmsgs; /* number of messages currently queued */ 33 __kernel_long_t __reserved[4]; /* ignored for input, zeroed for output */ 34}; 35 36/* 37 * SIGEV_THREAD implementation: 38 * SIGEV_THREAD must be implemented in user space. If SIGEV_THREAD is passed 39 * to mq_notify, then 40 * - sigev_signo must be the file descriptor of an AF_NETLINK socket. It's not 41 * necessary that the socket is bound. 42 * - sigev_value.sival_ptr must point to a cookie that is NOTIFY_COOKIE_LEN 43 * bytes long. 44 * If the notification is triggered, then the cookie is sent to the netlink 45 * socket. The last byte of the cookie is replaced with the NOTIFY_?? codes: 46 * NOTIFY_WOKENUP if the notification got triggered, NOTIFY_REMOVED if it was 47 * removed, either due to a close() on the message queue fd or due to a 48 * mq_notify() that removed the notification. 49 */ 50#define NOTIFY_NONE 0 51#define NOTIFY_WOKENUP 1 52#define NOTIFY_REMOVED 2 53 54#define NOTIFY_COOKIE_LEN 32 55 56#endif