p_511 编译器在没有指示下,会做‘ safe optimization',因此有些优化在没有参数的指示下是不会对代码做优化的,故在程序中应该避免某一类代码,因为它们妨碍了编译器做优化. optimization blocks: aspects of programs that can severely limit the opportunities for a compiler to generate optimized code; 两类optimization blocks: 1.memo…

prcesssor在运行时,假设program counter的值为a0, a1, ... , an-1,每个ak表示相对应的instruction的地址.从ak到ak+1的变化被称为control transfer.一系列的control transfers被称为control flow. exceptions是指一些event,这些event表明当前的system.processor或executing program存在某些状况(详见1.2).exceptions会导致control fl…

1.1 information is bits + context All computer programs are just a sequence of bits, each with a value of 0 or 1, organized in 8-bit chunks called by bytes. 8 bits = 1 byte All files is binary files. 1.2 Programs are translated by other programs into…

String类实现了java.io.Serializable, Comparable<String>, CharSequence这三个interface. 看了下这三个interface中的方法,发现CharSequence中在1.8版本jdk中新增了两个方法: public default IntStream chars(){...} public default IntStream codePoints() {...} 注意这两个方法是在interface内定义的,并且有方法实现的,int…

承如“optimization blocks”文中所述,由于相同的指针可能指向相关的内存区,因此编译器将不做过分的优化…… 特意搜了下编译器在不同的优化等级下都有哪些默认优化,因此有了此记录(比较长,尽管只讲述了fstrict-aliasing  ……) 下述内容引述自:http://dbp-consulting.com/tutorials/StrictAliasing.html http://cellperformance.beyond3d.com/articles/2006/06/under…

###########sample 1 https://www.cnblogs.com/hanshanxiaoheshang/p/10304672.html (不错) 如何从zabbix server 数据库端获取数据. 3.zabbix配置入门   Zabbix模板 zabbix组件:    zabbix-server    zabbix-database    zabbix-web    zabbix-agent    zabbix-proxyzabbix逻辑组件:    主机组.主机   …

以下笔记参考自Boyd老师的教材[Convex Optimization]. I. Mathematical Optimization 1.1 定义 数学优化问题(Mathematical Optimization) 有如下定义: \[ \begin{align} &minimize \, f_0(x) \notag \\ &subject \, to \, f_i(x)≤b_i, \, i=1,...,m \tag{1.1} \end{align} \] 向量\(x=(x_1,...,x…

1. 一段查看地址内容的代码 代码: #include <stdio.h> typedef unsigned char *byte_pointer; void show_bytes(byte_pointer start, int len) { int i; ; i < len; i++) { printf(" %.2x", start[i]); } printf("\n"); } void show_int(int x) { show_bytes(…

I. 仿射凸集(Affine and convex sets) 1. 线与线段 假设\(R^n\)空间内两点\(x_1,x_2\, (x_1≠x_2)\),那么\(y=\theta x_1+(1-\theta)x_2, \theta∈R\)表示从x1到x2的线.而当\(0≤\theta≤1\)时,表示x1到x2的线段. 2.仿射集 仿射集(Affine sets) 定义: 假设有一个集合\(C∈R^N\),如果通过集合C中任意两个不同点之间的直线 (上的任何点) 仍在集合C中,那么称集合C是仿射…

14.5. Statements There are many kinds of statements in the Java programming language. Most correspond to statements in the C and C++ languages, but some are unique. As in C and C++, the if statement of the Java programming language suffers from the s…

1. Detecting Performance Issues 2. Scripting Strategies 3. The Benefits of Batching 4. Kickstart Your Art 5. Faster Physics 6. Dynamic Graphics 7. Masterful Memory Management 8. Tactical Tips and Tricks 1. Detecting Performance Issues  The Unity Prof…

Chapter 2. The Structure of the Java Virtual Machine 内容列表 2.1. The class File Format (class文件的格式) 2.2. Data Types (数据类型) 2.3. Primitive Types and Values (原始数据类型和值) 2.3.1. Integral Types and Values 2.3.2. Floating-Point Types, Value Sets, and Values 2…

使用Code::blocks在windows下写网络程序 作者 He YiJun – storysnail<at>gmail.com 团队 ls 版权 转载请保留本声明! 本文档包含的原创代码根据General Public License,v3 发布 GPLv3 许可证的副本可以在这里获得:http://www.gnu.org/licenses/gpl.html 本文档根据GNU Free Documentation License 1.3发布 GFDL1.3许可证的副本可以在这里获得:ht…

Memory Optimization If a document deals with a lot of data or large elements, such as images, it is not wise to build the sections entirely in memory and then add them to the document. If you take a look at the code above and run it with 1,000,000 ro…

I know it well:I read it in the grammar long ago.—William Shakespeare, The Tragedy(悲剧:灾难:惨案) of Titus Andronicus This chapter introduces the grammar of the good parts of JavaScript, presenting a quick overview of how the language is structured. We wi…

Why, every fault’s condemn’d ere it be done:Mine were the very cipher of a function. . .—William Shakespeare, Measure for Measure The best thing about JavaScript is its implementation of functions. It got almost everything right. But, as you should e…

https://msdn.microsoft.com/en-us/library/ff647787.aspx Retired Content This content is outdated and is no longer being maintained. It is provided as a courtesy for individuals who are still using these technologies. This page may contain URLs that we…

8.2.1.15 ORDER BY Optimization ORDER BY 优化 在一些情况下, MySQL 可以使用一个索引来满足一个ORDER BY 子句不需要做额外的排序 index 可以用于即使ORDER BY 不精确的匹配index, 只要所有未使用的索引的部分和所有额外的ORDER BY 列是WHERE 子句中的常量. 下面的查询使用index来解决ORDER BY 部分: SELECT * FROM t1 ORDER BY key_part1,key_part2,... ; S…

Spring's AOP Framework Let's begin by looking at Spring's own AOP framework - a proxy-based framework that works in pure Java. You can use it in any application server and all the required classes are included in the Spring distribution. Although man…

CSAPP  && lab5 实验指导书: http://download.csdn.net/detail/u011368821/7951657 实验材料: http://download.csdn.net/detail/u011368821/8019293 搞定这个实验还是要看一下曾经的笔记,再复习一下block的组织方式.仅仅看link里面第11节,动态内存分配的部分就能够了 http://blog.csdn.net/cinmyheart/article/details/3813637…

Blocks and Variables https://developer.apple.com/library/ios/documentation/cocoa/conceptual/Blocks/Articles/bxVariables.html http://stackoverflow.com/questions/16149653/what-is-the-role-of-the-copy-in-the-arc This article describes the interaction be…

CSAPP:第十章 系统级I/O 10.1 unix I/O10.2 文件10.3 读取文件元数据10.4 读取目录内容10.5 共享文件10.6 我们该使用哪些I/O函数? 10.1 unix I/O   所有的I/O设备(例如网络.磁盘和终端)都被模块化为文件,而所有的输入和输出都被当作对相应文件的读和写来执行.这种允许Linux内核引出一个简单.低级的应用接口,称为Unix I/O,这使得所有的输入和输出都能以一种统一且一致的方式来执行: 打开文件. 改变当前的文件位置, 读写文件. 关闭…

CMU是全美以至全球公认的CS最猛的大学之一,没办法,作为CS的发源地,再加上三位神一样的人先后在此任教:Alan Perlis(CS它祖宗+第一届Turing奖获得者).Allen Newell(AI缔造者+Turing奖获得者)和Herbert Simon(AI缔造者+Turing奖获得者+Nobel经济学奖获得者,当代的Leibniz,偶佩服到死的一个天神下凡级的人物,他的自传 Models of my life偶特意珍藏了两本),三位巨头培养出一大摊小神级别的人物,这一大摊小神级的人物又…

  (a) an if-then-else (b) a while loop (c) a natural loop with two exits, e.g. while with an if...break in the middle; non-structured but reducible (d) an irreducible CFG: a loop with two entry points, e.g. goto into a while or for loop   控制流图是代码的一种表…

From Thinking in Java 4th Edition 并发 线程可以驱动任务,因此你需要一种描述任务的方式,这可由Runnable接口来提供. 要想定义任务,只需要实现Runnable接口,并编写run()方法,使得该任务可以执行你的命令. public class LiftOff implements Runnable { protected int countDown = 10; // Default private static int taskCount = 0; priv…

MASTERING CREATIVITY, 1st EditionThis guide is free and you are welcome to share it withothers.From James Clear:For most of my life, I didn't consider myself to be particularly creative. I didn't play a musicalinstrument (or even know how to read mus…

4.1 Introduction 4.2 stat, fstat, fstatat, and lstat Functions The lstat function is similar to stat, but when the named file is a symbolic link, lstat returns information about the symbolic link, not the file referenced by the symbolic link. 4.3 文件类…

Optimization Welcome to the optimization's programming assignment of the hyper-parameters tuning specialization. There are many different optimization algorithms you could be using to get you to the minimal cost. Similarly, there are many different p…

This article is a combined effort of Innofied Javascript developers Puja Deora and Subhajit Ghosh) We have been working on a project for past 8 months (ongoing). Over the course of this project, we have learnt that small tweaks to general coding prac…

Chapter 3. Filtering Patterns 本章的模式有一个共同点:不会改变原来的记录.这种模式是找到一个数据的子集,或者更小,例如取前十条,或者很大,例如结果去重.这种过滤器模式跟前面章节的不同是,从更小的粒度认识数据,例如特殊用户生成的记录,或文本中用得最多的前10个动词.简单的说,过滤器允许你更清楚的看清数据,像在显微镜下一样.也可以认为是搜索的一种形式.如果你对找出所有有着特殊信息的记录感兴趣,你就可以过滤出不匹配搜索条件的记录. 抽样,一种通用的过滤程序,是指取出数据的…