fifo

I'm currently trying to create a kernel module that will produce data based on kernel events and push them to a file. After reading that this is bad (and I agree), I decided it would make more sense to have the data in a /proc file that a user program could pull from when necessary. However, this idea led to all sorts of problems, particularly when and how to clear out this file. So I thought... "why don't I make a named pipe in /proc and read from that?" I've got the general gist of setting a read function and a write function for a proc file, but I'm still having conceptual trouble with how

2019-2020-1 20175208 20175218 20175230 实验二 固件程序设计 一、实验内容 1、固件程序设计-1-MDK 注意不经老师允许不准烧写自己修改的代码 三人一组 参考云班课资源中“信息安全系统实验箱指导书.pdf “第一章，1.1-1.5安装MDK，JLink驱动，注意，要用系统管理员身分运行uVision4，破解MDK（破解程序中target一定选ARM） 提交破解程序中产生LIC的截图 提交破解成功的截图 2、固件程序设计-2-LED 注意不经老师允许不准烧写自己修改的代码 参考云班课资源中“信息安全系统实验箱指导书.pdf “第一章，1.4” KEIL-MDK 中添加 Z32 SC-000 芯片库，提交安装截图 参考云班课资源中“信息安全系统实验箱指导书.pdf “第一章，1.9”完成LED实验，注意“打开Z32的电源开关前，按住Reboot按键不放，两次打开电源开关，Z32即可被电脑识别，进行下载调试。提交运行结果截图 实验报告中分析代码 3、固件程序设计-3-UART 注意不经老师允许不准烧写自己修改的代码 参考云班课资源中“信息安全系统实验箱指导书.pdf “第一章，1.4” KEIL-MDK 中添加 Z32 SC-000 芯片库，提交安装截图 参考云班课资源中“信息安全系统实验箱指导书.pdf “第一章，1.0

How can we treat a Mysql table as a limited FIFO buffer (Queue). Objectives are : The table at a time can have only N number of rows. When a row is inserted, the oldest row shpuld be deleted to maintain the row count as N. Pls suggest approaches. UPDATE: Sorry guys, as many pointed I changed my question from STACK to FIFO queue Past Mysql 5 you could use a trigger to achieve this. http://dev.mysql.com/doc/refman/5.0/en/create-trigger.html then your triggered sql would be along the lines off: DELETE FROM foo WHERE id NOT IN (SELECT id FROM foo ORDER BY id DESC LIMIT 10) You can just get count

timegen学习记录 最近重新从零开始学习FPGA，把基础打扎实。用visio画波形图，感觉这画波形图的效率不高、使用不够方便。自己是用过timegen软件，感觉画得比较快，方便时序对齐。但指导老师说，timegen画的图不方便导出到文档、不方便后期修改，交作业也都是用visio的格式。突然在csdn上看到有timegen波形图导出到visio里面修改的方法，于是转载，把方法整理一下。 TimeGen官网下载链接： http://www.xfusionsoftware.com/download_timegen.html 百度网盘下载链接：https://pan.baidu.com/s/1Fn1wnjyFr3PCbBmQobMBsQ 提取码：628a 画完之后去掉背景logo： （1）View-TimeGen Logo去掉勾(即去掉右下角的字符)； View-Bounding Rectangle去掉勾(去掉四周黑色边框)； （2）File-Export-Enhanced MetaFile(.emf)，导出为.emf文件； （3）打开visio软件，打开该文件，选择*.emf 打开文件后，①可以右键点击图片-组合-取消组合，②也可以左键选中该图片，点击上方的组合-取消组合。取消组合后就可以随意删除了。 可以在visio中修改，并重新另存为.vsdx的格式。 timegen的help

I need a python script implementing a circular buffer for rows in a text file limited to N rows like this: row 1 -> pop row 2 row 3 | | push -> row N What's the best solution? EDIT: This script should create and maintain the text file which only contains the latest N lines. Then it should pop the first line pushed in. Like a fifo buffer. Try my recipe and sorry for italian usage: #!/usr/bin/env python # -*- coding: utf-8 -*- # # fifo(.py) # # Copyright 2011 Fabio Di Bernardini <fdb@altraqua.com> # # This program is free software; you can redistribute it and/or modify # it under the terms of

I'm trying to write to FIFO file locate on NFS mount and it blocks. What could be the problem? My /etc/export: /tmp/test/ 10.0.0.0/24(rw,no_root_squash,async) ls /tmp/test on NFS server and client is the same prw--w--w- 1 root root 0 2009-06-24 17:28 ui-input and I'm writing as root Thanks. A FIFO is meant to be an inter-process communication mechanism. By trying to export the FIFO via NFS, you are asking the kernel to treat the local inter-process communication as more of a network communication mechanism. There are a number of issues associated with that, the most obvious one being that the

同步FIFO的结构图： 有四个逻辑块组成：RAM（实现数据的存取）、读控制（读地址控制）、写控制（写地址控制）、状态块（控制空满判断） 接口定义：时钟信号（clk）、复位信号（fifo_rst）、使能信号（read_en、write_en）、数据信号（fifo_in、fifo_out)、空满信号（fifo_empty、fifo_full）、计数器 参数声明：data_width、addr_width 信号类型定义：wire clk、fifo_rst、read_en、write_en、fifo_in reg fifo_out、fifo_emoty、fifo_full reg read_addr、write_addr 四大程序块： RAM结构实现（可以写也可以通过例化实现） 计数器控制实现 读写地址的控制实现 空满信号的判断实现 来源： https://www.cnblogs.com/baihuashan/p/11806726.html

On a Bash script I want to keep MySQL sessions open across several sequential accesses; the common way to access MySQL is by opening an individual session for each SQL command, or set of commands, such as mysql -u user -e "show tables;" The limitation of this method is the loss of atomicity and lock statuses for those transactions which need to be twofold: for example, it's not possible to preserve the lock status on a table T for the whole length of the following twofold operation: ### Minimalistic example data=$(mysql -e "\ lock table T write; select col from T; ") # ... # parse 'data' and