execute typical instruction 1/1,000,000,000 sec = 1 nanosec fetch from L1 cache memory 0.5 nanosec branch misprediction 5 nanosec fetch from L2 cache memory 7 nanosec Mutex lock/unlock 25 nanosec fetch from main memory 100 nanosec send 2K bytes over…

Teach Yourself Programming in Ten Years——用十年教会自己编程 作者:Peter Norvig 译者:刘海粟 本文原文为:http://norvig.com/21-days.html 该翻译文档的PDF版可以在这里获得:http://download.csdn.net/source/2983778 为何万事都如此仓促? 随便走进一家书店,你就能看到<7天学会Java>以及各种万变不离其宗的书籍,形如:在数天或是数小时内学会Visual Basic.Wind…

Table of Contents SELECTs -- do's and don'tsINDEXingENGINE DifferencesOptimizations, and notPARTITIONingMemory UsageCharacter SetsDatatypes - Directly supportedDatatypes - ImplicitHardwarePXC / GaleraData WarehouseMiscellanyPostlog Brought to you by…

原文地址:http://mysql.rjweb.org/doc.php/ricksrots Brought to you by Rick James Here are 160+ tips, tricks, suggestions, etc. They come from a decade of improving performance in MySQL in thousands of situations. There are exceptions to the statements belo…

1. IIC协议: <<um_s3c2440a_rev10.pdf>>  p481 Figure 20-3. IIC-Bus Interface Data Format<<AT24C08_DataSheet.pdf>>  Figure 1-12 Bus Timing and Device operations iic总线里的角色:    主机(Master):初始化发送.产生时钟信号和终止发送的器件     从机(Slave):被主机寻址的器件 I2C的原则…

TimeUnit是  java.util.concurrent 中的一个枚举类.一般让线程进行睡眠时使用: TimeUnit.MILLISECONDS.sleep(100); 比如上面一行代码表示让当前线程睡眠100毫秒. 相比Thread.sleep()方法的一个好处就是, TimeUnit可以设置时间单位,比如上面的毫秒级别,看下面源码,有7个选项,纳秒.微妙.毫秒.秒.分钟.小时.天. package java.util.concurrent; /** * A <tt>TimeUnit&…

ExceptionTranslationFilter is a Spring Security filter that has responsibility for detecting any Spring Security exceptions that are thrown. Such exceptions will generally be thrown by an AbstractSecurityInterceptor, which is the main provider of aut…

From  http://simongui.github.io/2016/12/02/improving-cache-consistency.html A typically web application introduces an in-memory cache like memcache or redis to reduce load on the primary database for reads requesting hot data. The most primitive desi…

转自:https://www.linuxtv.org/downloads/legacy/video4linux/API/V4L2_API/spec-single/v4l2.html Video for Linux Two API Specification Revision 2.6.32 Michael H Schimek <mschimek@gmx.at> Bill Dirks Original author of the V4L2 API and documentation. Hans V…

spring-boot 整合 redis 注:redis服务器要先开启 pom文件: <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> 配置文件yml: spring: redis: #redis数据库地址 host: localho…

A computer system with read/write access to storage devices creates a snapshot of a data volume at a point in time while continuing to accept access requests to the mirrored data volume by copying before making changes to the base data volume. Multip…

Data Management ObjectivesBy the end o this module, you should understand the fundamentals of data management, including:1.Explain typical data management operations.2.Describe typical user cases for inserting system fields.3.List the ways to obtain…

Appendix A 附录A PC hardware Pc的硬件 This appendix describes personal computer (PC) hardware, the platform on which xv6 runs. 这个附录描述了xv6运行的平台——个人计算机(PC)的硬件. A PC is a computer that adheres to several industry standards, with the goal that a given piece o…

MSDN Blogs > Zemblanity > Windows And Video Memory   Windows And Video Memory Tom_Mulcahy 11 Feb 2009 12:13 PM  The following explanations are overviews. In the interests of brevity, they neglect some corner cases. Definitions: Video memory: For our…

1 源码下载 github上初始版本是bitcoin-0.1.5,可以从https://github.com/bitcoin/bitcoin下载,但是从网上可以找到更老版本bitcoin-0.1.0,例如可以从如下地址下载: https://github.com/Dan-McG/bitcoin-0.1.0 网上可以搜到一封关于这个版本的说明邮件,内容如下 Announcing the first release of Bitcoin, a new electronic cash system t…

FIELD OF THE DISCLOSURE The subject matter of the present disclosure relates to a framework for handling graphics animation and compositing operations for a graphical user interface of a computer system application. BACKGROUND OF THE DISCLOSURE Mac O…

BACKGROUND The present invention generally relates to the processing of graphics data, and particularly relates to methods and apparatus for controlling approximation errors in the rendering of three-dimensional graphics data. State-of-the-art three-…

BACKGROUND 1. Field The present invention generally relates to rendering two-dimension representations from three-dimensional scenes, and more particularly to using ray tracing for accelerated rendering of photo-realistic two-dimensional representati…

From:   http://preshing.com/20120710/memory-barriers-are-like-source-control-operations/ If you use source control, you’re on your way towards understanding memory ordering, an important consideration when writing lock-free code in C, C++ and other l…

在ASIC设计中,有两种HDL construct来描述delay信息: 1)Distributed delays:通过specify event经过gates和nets的time,来描述delay; 对于net和gate都有三种delay信息: 1)rise delay   2)fall delay    3)transition to high-impedance value 只有一种delay时,所有change都使用这种delay,两个delay值时,才分为rise/fall 每一种de…

Doc ID 428681.1 Applies to: Oracle Database - Enterprise Edition - Version 10.2.0.1 to 11.2.0.1.0 [Release 10.2 to 11.2]Information in this document applies to any platform. Goal The goal of this note is to provide steps to add, remove, replace or mo…

彩色阴极射线管的剖面图: 1. 电子QIANG Three Electron guns (for red, green, and blue phosphor dots)2. 电子束 Electron beams3. 聚焦线圈 Focusing coils4. 偏向线圈 Deflection coils5. 阳极接点 Anode connection6. Mask for separating beams for red, green, and blue part of displayed ima…

转自:http://www.cnblogs.com/shangdawei/p/4760933.html 彩色阴极射线管的剖面图: 1. 电子QIANG Three Electron guns (for red, green, and blue phosphor dots)2. 电子束 Electron beams3. 聚焦线圈 Focusing coils4. 偏向线圈 Deflection coils5. 阳极接点 Anode connection6. Mask for separating…

This document provides you with interesting background information about the technology that underpins XJTAG. You do not need to know any of this however to be able to use the XJTAG development system as XJTAG tests are developed in a high-level prog…

There is no doubt that Node.js is one of the fastest growing platforms today. It can be found at start-ups and enterprises throughout all industries from high-tech to healthcare. A lot of people have written about the reasons for its popularity and w…

A multiprocessing system having a plurality of processing nodes interconnected by an interconnect network. To optimize performance during spin-lock operations, a home agent prioritizes the servicing of read-to-own (RTO) transaction requests over the…

(一):次优最近邻:http://en.wikipedia.org/wiki/Nearest_neighbor_search 有少量修改:如有疑问,请看链接原文.....1.Survey:Nearest neighbor search (NNS), also known as proximity search,similarity search orclosest point search, is anoptimization problem for finding closest (or mo…

Timing delays in a double data rate (DDR) dynamic random access memory (DRAM) controller (114, 116) are trained. A left edge of passing receive enable delay values is determined (530). A final value of a receive data strobe delay value and a final va…

https://semiwiki.com/x-subscriber/clk-design-automation/4481-variation-alphabet-soup/ n response, foundries have broken out on-die variation as a separate component in their SPICE models. They created global corners for slow, typical and fast. These…

小结: 1. conflicting access 2.性能危害 优化 The cost of race detection varies by program, but for a typical program, memory usage may increase by 5-10x and execution time by 2-20x. 3.典型案例与修复 Accidentally shared variable // ParallelWrite writes data to file1…