1 advent 2017

(), the C runtime will create such an anonymous mapping instead of using heap memory. "Chunk" means larger than Mmap_threshold, default 128KB, can be adjusted by MALLOCP (). BBS and Data section? In the C language, BSS and data segments hold the contents of static (global) variables. The difference is that BSS holds uninitialized static variable content, and their values are not set directly in the program's source code. The BSS memory area is anonymous and it does not map to any files. If you

Bzoj [2017 provincial team 10 join test promotion competition 1] (4765 4766 4767), bzoj4765 Bzoj 4765 -- multipart + dfs sequence + tree array: Consider chunks. Set ~ N is divided into sqrt (n) blocks, and the number of its ancestors in each block is recorded for each vertex. modify a vertex to enumerate each shard and modify it. When querying [l, r], if a block is in [l, r], add it to the answer directly

Bzoj [2017 provincial team 10 join test promotion competition 1] (4765 4766 4767), bzoj4765 Bzoj 4765 -- multipart + dfs sequence + tree array: Consider chunks. Set ~ N is divided into sqrt (n) blocks, and the number of its ancestors in each block is recorded for each vertex. modify a vertex to enumerate each shard and modify it. When querying [l, r], if a block is in [l, r], add it to the answer directly

identifier. Camel spelling, Studly caps, or other mixed uppercase and lowercase characters are not allowed in the name. Global variables and functions should select names that contain descriptive content, use lowercase letters, and underline words when necessary. In the source code less use TypeDef, IFDEF. diff -urN linux-old/ linux-new/ > my-patch //通过源码和加进了所修改部分的源代码两份代码创建补丁diff -u linux-old/some/file linux-new/some/file > my-patch //对单独的文件进行diffdiffstat -p1 my-patch //列出补丁所引起的变

page, such as how many replies are under the topic A page that toggles the route to be displayed, such as another page of navigation In this case, there are obviously a number of possible scenarios for rendering segmentation All-in-client rendering 1, 2, 3 render on server, 4 wait until user clicks from browser 1, 2 render on server, comment loaded by client Only

is added to the Dirty page list. The pages in the Dirty page list are then periodically written back to disk by a process (write-back process), so that the data in the disk is eventually consistent with in-memory.11. The page cache is searched by two parameters address_space redemption plus an offset. Each address_space object has a unique cardinality, which is stored in the address_space struct. The cardinality is a binary tree, and you can quickly retrieve the desired page in the cardinality

system calls provided by the operating system implementationRegister Pass parameter restriction: the length of the parameter must not exceed the register length and cannot exceed 32 bits; no more than 6 parameters (EBX,ECX,EDX,ESI,EDI,EBP) outside of the system call number (EAX)C Language inline assembly syntax:__ASM__VOLATILE__ (Assembly statement template;Output part;Input part;Destruction of the description section);Volatile means not to allow the compiler to optimize the code, you can not w

the same way as the former, bytes each character occupies only one byte.The pass-through method that is represented in Unicode str encode() can be encoded as a specifiedbytes----要把bytes变为str，就需要用decode()方法The 4.3 len() function calculates the str number of characters, and if bytes so, the len() function calculates the number of bytes:4.4 Formatting %d integers (formatted integers and floating-point numbers can also specify whether to fill 0 and integers with decimals)

1. Two Select Content Interchange2. radio button consent to click Next3. Select All BoxSelect all: September 27, 2017 JS (1. Two Select Content Interchange 2. The radio button agrees to click Next 3. Select All box)

The queue has the feature of FIFO: Delete data in Team head (out of line), insert data at the end of team (incoming team);What is a design queue? What unique features does it have? Simulation of discrete events (sequencing of discrete events, such as instruction decoding queues in the CPU) Job scheduling in the operating system (one CPU operation for multiple jobs) Simplified programming Basic Operations for queues:Chain queues in data structures (

;publicclassmain{ publicstaticvoidmain (String[]args) { scannerin=newscanner (system.in); stringnum=in.next ();int Result=0;while (result!=6174) { intleft=0; intright=0; char[]temp=creat (num); char[]l=newchar[4]; arrays.sort (temp); for (inti=3;i>=0;i--) { left=left*10+temp[i]-' 0 '; right=right*10+temp[3-i]-' 0 '; l[i]=temp[3-i] ;} if (left==right) { system.out.println (Newstring (L) + "-" +new String (temp) + "=0000"); return;} result=left-right; system.out.println (Newstring (L) + "-" +newst

is the names and one is the address of Maven. The main is the above several parameters.④-dependent maven TagsIt is important to note that the jar package naming rules: artifactid-version[-classifier].packagingEngineering of ⑤mavenPom.xml: a dependency used to define or add a jar packageSrc-main: for storing Java source filesSrc-test: for storing test casesTarget: This is the jar package used to generate the corresponding class file or release⑥eclipse common commands in Maven　　maven build: This

struct indicates that in Kobject, the Ktype field points to the object. The Kobject is also referred to as the set and the Kset, Kset set and represented by the struct kset struct.Virtual file System (SYSFS)SYSFS provides the user with an attempt to kobject the object hierarchy. Helps users to observe the topology of various devices in a system in a simple file system. With the property structure object, Kobject can provide a kernel variable to the user to read the write in the same way as the

memory. Since the kernel is dealing with data that requires some relevant control information, each buffer has a corresponding descriptor. This descriptor is represented by the Buffer_head struct, called the buffer header, defined in file struct buffer_head{ unsigned long b_state; //缓冲区状态标志 struct buffer_head *b_this_page; //页面中的缓冲区 struct page *b_page; //存储缓冲区的页面 sector_t b_blocknr; //起始块号 size_t b_size; //映像的大小 char *b_data; //页面内的数据指针 .

20172330 2017-2018-1 "Java program design" Fifth week study summary textbook study content summary fifth chapter The first is the understanding of the various operators: just beginning to think that equality is =, there are some other symbols are quite simple, and then in the further learning to know the "= =" and "! = "are all equal operators, and"! "," "," | | " Represent non, with, or.Problems in te

20172330 2017-2018-1 "Java Program design" Fourth week study summary textbook study summaryThis week's content is more and more complex, including chapters fourth and seventh. The fourth chapter introduces the definition and concept of class structure, and gives us a lot of examples to show the method and application of the custom class, and discusses the structure and use of the method definition:

20165218 2017-2018-1 "Java Programming" 7th Week study summary textbook Learning content summary jdbc and MySQL database Database functions: Data storage, query, modification, security MySQL: Database; JDBC: API for manipulating databases APIs (application Programming Interface, application programming interfaces) are pre-defined functions designed to provide the ability of appli

% Quantitative ratio (6%) 　0.96%　 　1.32%　 　1.2%　 　0.96%　 　0.96%　 　0.6%　 Eighth Week ratio 18% 22% 18% 16% 14% 12% Quantitative ratio (6%) 　1.28g　 　1.32%　 　1.28g　 　0.96%　 　0.84%　 　0.72%　 Alpha Stage Scale 25.53% 19.15% 20.57% 13.48% 13.48% 7.8%

. A file can have multiple virtual addresses (identified by multiple vm_area_struct) but can have only one physical address (address_space data structure). Each Address_space object has a unique base tree. Motoki is a binary tree that can quickly retrieve the desired data in the base tree as long as the file offset is specified. This data is called dirty data when the page cache data is newer than the data stored in the background. Writeback in the Linux page cache is done by the flu

offset is specified. Page Cache search function Find_get_page () to call Radix_tree_lookup (), the function searches the specified base tree for the specified page.PS: Learning so much about the implementation of the Linux system, more and more the importance of data structure, the first sense of data structure This course is "waste", it may be that I write too little code. Now it seems that the data structure is really the art of art.Multithreading to avoid congestionA single thread may clog u