/* -*- mode: C; c-basic-offset: 4 -*- */ /* ex: set shiftwidth=4 tabstop=4 expandtab: */ /* * Copyright (c) 2008-2014, Georgia Tech Research Corporation * Copyright (C) 2014, Prevas A/S * Copyright (c) 2015, Rice University * All rights reserved. * * Author(s): Neil T. Dantam * Kim Boendergaard Poulsen * Georgia Tech Humanoid Robotics Lab * Under Direction of Prof. Mike Stilman * * * This file is provided under the following "BSD-style" License: * * * Redistribution and use in source and binary forms, with or * without modification, are permitted provided that the following * conditions are met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above * copyright notice, this list of conditions and the following * disclaimer in the documentation and/or other materials provided * with the distribution. * * * Neither the name of the copyright holder the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * */ /** \file ach_private_generic.h * \author Neil T. Dantam, Kim Boendergaard Poulsen */ #ifndef ACH_PRIVATE_GENERIC_H #define ACH_PRIVATE_GENERIC_H #ifdef __cplusplus extern "C" { #endif /** prefix to apply to channel names got get the chardev file name */ #define ACH_CHAR_CHAN_NAME_PREFIX_PATH "/dev/" #define ACH_CHAR_CHAN_NAME_PREFIX_NAME "ach-" /** Name of chardev channel controlling device */ #define ACH_CHAR_CHAN_CTRL_NAME "/dev/achctrl" /** magic number that appears the the beginning of our mmaped files. * * This is just to be used as a check. */ #define ACH_SHM_MAGIC_NUM 0xb07511f3 /** A separator between different shm sections. * * This one comes after the header. Should aid debugging by * showing we don't overstep and bounds. 64-bit for alignment. */ #define ACH_SHM_GUARD_HEADER_NUM ((uint64_t)0x1A2A3A4A5A6A7A8ALLU) /** A separator between different shm sections. * * This ones comes after the index array. Should aid debugging by * showing we don't overstep and bounds. 64-bit for alignment. */ #define ACH_SHM_GUARD_INDEX_NUM ((uint64_t)0x1B2B3B4B5B6B7B8BLLU) /** A separator between different shm sections. * * This one comes after the data section (at the very end of the * file). Should aid debugging by showing we don't overstep and * bounds. 64-bit for alignment. */ #define ACH_SHM_GUARD_DATA_NUM ((uint64_t)0x1C2C3C4C5C6C7C8CLLU) /** Header for shared memory area. * * There is no tail pointer here. Every subscriber that opens the * channel must maintain its own tail pointer. */ typedef struct ach_header { uint32_t magic; /**< magic number of ach shm files */ size_t len; /**< length of mmap'ed file */ char name[1+ACH_CHAN_NAME_MAX]; /**< Name of this channel */ union { struct { size_t index_cnt; /**< number of entries in index */ size_t data_size; /**< size of data bytes */ size_t data_head; /**< offset to first open byte of data */ size_t data_free; /**< number of free data bytes */ size_t index_head; /**< index into index array of first unused index entry */ size_t index_free; /**< number of unused index entries */ clockid_t clock; /**< clock used for this channel */ #ifdef ACH_POSIX int anon; /**< is channel in the heap? */ #endif }; uint64_t reserved[16]; /**< Reserve to compatibly add future variables */ }; struct /* anonymous structure */ { #ifdef ACH_POSIX pthread_mutex_t mutex; /**< mutex for condition variables */ pthread_cond_t cond; /**< condition variable */ #endif #ifdef ACH_KLINUX struct rt_mutex mutex; wait_queue_head_t readq; #endif int dirty; } sync; /**< variables for synchronization */ #ifdef ACH_KLINUX struct kref refcount; struct rt_mutex ref_mutex; #endif /* should force our alignment to 8-bytes... */ uint64_t last_seq; /**< last sequence number written */ } ach_header_t; /** Entry in shared memory index array */ typedef struct ach_index { size_t size; /**< size of frame */ size_t offset; /**< byte offset of entry from beginning of data array */ uint64_t seq_num; /**< number of frame */ } ach_index_t; #ifdef __cplusplus } #endif /** Gets pointer to guard uint64 following the header */ #define ACH_SHM_GUARD_HEADER( shm ) ((uint64_t*)((ach_header_t*)(shm) + 1)) /** Gets the pointer to the index array in the shm block */ #define ACH_SHM_INDEX( shm ) ((ach_index_t*)(ACH_SHM_GUARD_HEADER(shm) + 1)) /** gets pointer to the guard following the index section */ #define ACH_SHM_GUARD_INDEX( shm ) \ ((uint64_t*)(ACH_SHM_INDEX(shm) + ((ach_header_t*)(shm))->index_cnt)) /** Gets the pointer to the data buffer in the shm block */ #define ACH_SHM_DATA( shm ) ( (uint8_t*)(ACH_SHM_GUARD_INDEX(shm) + 1) ) /** Gets the pointer to the guard following data buffer in the shm block */ #define ACH_SHM_GUARD_DATA( shm ) \ ((uint64_t*)(ACH_SHM_DATA(shm) + ((ach_header_t*)(shm))->data_size)) /** Default number of index entries in a channel */ #define ACH_DEFAULT_FRAME_COUNT 16 /** Default nominal frame size for a channel */ #define ACH_DEFAULT_FRAME_SIZE 512 #endif