polly poll

1, select, poll a few shortcomingsRecall the interface of select and pollint Select (int Nfds, fd_set *readfds, fd_ Set *writefds, fd_set *exceptfds, struct Timeval *timeout);int Poll (struct POLLFD *fds, nfds_t nfds, int timeout);The two multiplexing implementations are characterized by: Each call to select and poll sets the set of events that the use

background logon. # After the configuration is complete, enable the Service to go to the background management interface: http: // 127.0.0.1: 8000/admin/ (2) teach you to start writing 1st Django1.6 apps # Create an app for voting. # Go To The mysite project root directory and create appdigoal @ digoal-pc :~ /Python/mysite $ python manage. py startapp pollsdigoal @ digoal-pc :~ /Python/mysite $ ls pollsadmin. py _ init _. py models. py urls. py views. py. Django has been generated, and the t

Implementation tutorial of MongoDB set field matching query method, mongodb Field MongoDB is a distributed file storage-based database. This article describes how to perform matching queries on the fields integrated in MongoDB records.1. Create a Test Database use testdbdb.createUser( { "user":"root", "pwd":"123456", "roles":[{"role" : "readWrite", "db":"testdb"}] } ) db.auth( { "user":"root", "pwd":"123456" } )2. Insert test da

? Cryptanalysis of the Bogdanov-Lee Cryptosystem by gottfriedherold From Gauthier's talk at CBC 2012. SeeHttp://cbc2012.mat.dtu.dk/slides/Gauthier.pdf [GOT12-eP] Val \ 'erie Gauthier and Ayoub Otmani and Jean-pierretillich: a distinguisher-based attack of a homomorphic encryptionscheme relying on Reed-Solomon Codes. eprint 2012/168 Cryptanalysis of [BL11-eP] [Bra12-eP-Whe] Zvika brakerski: When homomorphism becomes aliability. eprint 2012/225 Cryptanalysis of [BL11-eP

instance, bytes found '-'. Join ([' 2012 '])# ' 2012 ' '-'. Join ([])# '' '-'. Join ([None])# typeerror:sequence Item 0:expected STR instance, Nonetype found '-'. Join (['])# '' ', '. Join ({' Dobi ': ' Dog ', ' Polly ': ' Bird ')# ' dobi,polly ' ', '. Join ({' Dobi ': ' Dog ', ' Polly ': ' Bird '}.values ())# ' Dog,bird 'Str.partition (Sep); Str.rpartition (Sep

Introduction to the Epoll modelEpoll but currently in Linux under the development of large-scale concurrent network programs popular candidates, Epoll in the Linux2.6 kernel formally introduced, and select similar, in fact, all I/O multiplexing technology, and there is no mystery.In fact, the design of concurrent network programs under Linux, there is always no lack of methods, such as the typical Apache model (Process Per Connection, abbreviated PPC), TPC (Thread perconnection) model, As well a

the difference between Epoll and Select/pollThe select,poll,epoll is a mechanism for IO multiplexing. I/O multiplexing is a mechanism by which multiple descriptors can be monitored, and once a descriptor is ready, the program can be notified of the appropriate action. The essence of select is 32 bits with 32 integers, that is, the 32*32= 1024来 identifier, and the FD value is 1-1024. When the value of FD exceeds the 1024 limit, the size of the fd_setsi

multiple customers at the same time. In general, there are three ways to choose, multi-process mode, multi-threaded mode and asynchronous mode. Among them, the multi-process mode of the server to a customer to use a process to provide services, because in the operating system, the generation of a process requires process memory replication, such as additional overhead, so that when the customer more performance will be reduced. To overcome the additional overhead of this build process, you can

Lt ;? Php/*** voting survey ***/include quot; isLogin. php quot; include quot ;.. /conn/config. inc. php quot;/* action operation initialization */if (emptyempty ($ _ REQUEST [ amp; #39; action amp; #39 /** * Voting investigation * * **/ Include "isLogin. php "; Include "../conn/config. inc. php "; /* Initialize the action */ If (emptyempty ($ _ REQUEST ['action']) { $ _ REQUEST ['action'] = 'list '; } Else { $ _ REQUEST ['action'] = trim ($ _ REQUEST ['action']); } If ($ _ REQUEST ['actio

In the previous study of network programming, I have learned I/O model Linux System application Programming-network programming (I/O model), below to learn the I/O model in the device driver application.Recall that there are five types of I/O models under Unix/linux, namely:A--blocking I/OB--Non-blocking I/OC--I/O multiplexing (SELECT and poll)D--signal-driven I/O (SIGIO)E--Asynchronous I/O (posix.1 aio_ series functions)Let's learn about blocking I/O

concept. Unfortunately, this concept has never been seen in university textbooks. It is not used when playing single-chip microcomputer. Event loop is available only in an operating system environment. The code basis of event loog also needs to use the concept of I/O multiplexing. Currently, three common API interfaces are available: Select, poll, and epoll. Glib is a cross-platform library. in Linux, it uses the

file descriptor in the collection can be read-writeSelect Pros and cons2.1 AdvantagesSelect () is currently supported on almost all platforms, and its good cross-platform support is one of its advantages.2.2 Disadvantages1, each call to select (), you need to copy the FD set from the user state to the kernel state, the cost of FD is very large, and each call to select () will need to traverse the kernel traversal of all the FD, the cost of the FD is also very large.2, a single process can monit

Custom admin formThis is enough to surprise us for several minutes, allCodeWe do not need to write.When we call Admin. Site. Register (poll), Django only asks you to edit this object and "speculate" how to display it on the Management page.In many cases, you may want to control admin styles and functions. You can tell Django the options when registering an object.Let's take a look at how to re-Sort fields in the form editing. Use the following code to

Label: Class Poll (models. Model): slug = models. Slugfield (unique_for_month= ' pub_date ')Question = models. Charfield (maxlength=255)Pub_date = models. Datetimefield ()Expire_date = models. Datetimefield ()def __repr__ (self):Return self.questionClass Meta:get_latest_by = ' Pub_date 'Class Choice (models. Model):Poll = models. ForeignKey (Poll, Edit_inline=mod

: 3. Add our poll app to the admin management interface. In the mysite/polls directory, create the admin. py file so that the content is as follows: # Coding: cp936from mysite. Polls. Models import poll, choicefrom Django. contrib import adminadmin. Site. Register (poll) Admin. Site. Register (choice) At this time, the corresponding

are three ways to choose, Multi-process mode , multi- threaded mode and asynchronous mode . Among them, the multi-process mode of the server to a customer to use a process to provide services, because in the operating system, the generation of a process requires process memory replication, such as additional overhead, so that when the customer more performance will be reduced. To overcome the additional overhead of this build process, you can use multithreading or asynchronous methods. In multi

The select,poll,epoll is a mechanism for IO multiplexing. The so-called I/O multiplexing mechanism, which means that through a mechanism, you can monitor multiple descriptors, and once a descriptor is ready (usually read-ready or ready to write), it notifies the program to read and write accordingly. But select,poll,epoll are essentially synchronous I/O because they all need to read and write when the read-

poll the line.Although the asynchronous approach is most efficient, it has its own drawbacks. Because of the asynchronous way, scheduling between multiple tasks is done by the server program itself, and once a problem occurs in one place, the entire server is in trouble. Therefore, to add functionality to such a server, on the one hand to comply with the server's own specific task scheduling, on the other hand to ensure that there is no error in the

Php voting (investigation ).? Php *** voting survey *** includeisLogin. php; include .. connconfig. inc. php; * action operation initialization * if (emptyempty ($ _ REQUEST [action]) {$ _ REQUEST [action] list;} else {$ _ /** * Voting investigation * * **/ Include "isLogin. php "; Include "../conn/config. inc. php "; /* Initialize the action */ If (emptyempty ($ _ REQUEST ['action']) { $ _ REQUEST ['action'] = 'list '; } Else { $ _ REQUEST ['action'] = trim ($ _ REQUEST ['action']); } If ($ _

fragmentation and management, and static Response Processing. For example, mobile phones and WEB websites both need to call API interfaces. They communicate directly with the gateway without worrying about whether the specific service is A or B. Project Demo Install the Ocelot Package: Install-Package Ocelot Create two projects, the gateway main project, DemoA and DemoB. In this way, both project A and Project B will specify the Gateway project and access the two projects through the gateway.