blocking tapestry

First, the conceptThe application uses API interfaces such as open, read, and so on to eventually operate the drive, with two outcomes-success and failure. Successful, well handled, returns the desired result directly, but fails, does it continue to wait, or does it return the type of failure? If you continue to wait for the process to hibernate, then this type of driver design is blocking, and if you do not wait to return the type of failure (reason)

Simply put:Blocking is to do not come back, has been in the waiting, until the completion of the process to return;Non-blocking is the first thing you do, I'll see if there's anything else. No, a find things are stuck, immediately report the leadership.Let's take the most commonly used send and recv two functions ...For example, if you call the Send function to send a certain byte, the work done inside the system is actually just transferring data (Co

Add another theoretical analysis with high handwriting to facilitate a deeper understanding. From: http://blog.csdn.net/historyasamirror/article/details/5778378 ========================================================== ================================== What are the differences between synchronous I/O and asynchronous I/O, blocking I/O, and non-blocking I/O? Different people may give different answers to t

Recently, I saw some posts and replies on the web, while searching some of the network's descriptions of blocking non-blocking differences, and found that many people have varying degrees of misunderstanding when describing the return of both sending and receiving and the difference in buffer handling. So I want to write an article to correct the error, and as a record convenient access, if reproduced, anno

A brief introduction to PHP non-blocking mode and a brief introduction to php blocking. A brief introduction to the non-blocking mode of PHP. a brief introduction to the non-blocking mode of php refers to the asynchronous communication between the Server and Client using the message mechanism of socket events. Let PHP

There are two ports that can be controlled for serial blocking (simultaneous control of Read and write): One is the opening of the serial port, whether the open function with O_ndelay, the second one can be opened after the serial port through the FCNTL () function to control.Definition of blocking:For Read,block refers to when the serial input buffer does not have data, the read function will be blocked here, ported to the serial input buffer data ca

communication mechanism, the bookstore owner will say, you wait, "I check", and then start to check Ah, and so check (maybe 5 seconds, may be a day) to tell you the results (return results).and the asynchronous communication mechanism, the bookstore owner directly told you I check Ah, check the phone to you, and then directly hung up (do not return the results). And then check it out and he'll call you on his own initiative. Here the boss calls back by "callback" this way.2.

Io:IO is the process of copying data from main memory and external devices (hard disks, terminals, and networks). IO is the underlying functional implementation of the operating system, which is done through I/O directives. Blocking and non-blocking:A bus from a to B, there are many points on the road may be people get off the train. The driver does not know which points will have who will get off the car, for need to get off the person, how to handle

1 Lao Zhang put the kettle on the fire and conforming the water. ( synchronous blocking )Lao Zhang thinks he's a little silly.2 Lao Zhang put the kettle on the fire, go to the living room to watch TV, and occasionally go to the kitchen to see if the water is open. ( synchronous non-blocking )Lao Zhang still feel a little silly, then become high-end, bought a will ring flute of that kind of kettle. After the

When looking at some frameworks, such as tornado, We will sometimes mention non-blocking at the implementation level. Some frameworks use async technology. So what is the difference between non-blocking and async? Below is my understanding: 1. There is no difference in many cases. When we talk about Asynchronization and non-blocking, we usually refer to how l

) { document.getElementById ("mydiv"). innerhtml=xmlhttp.responsetext; } } Xmlhttp.open ("GET", "Test1.txt",true); Xmlhttp.send ();This function is a callback, which is called when the server returns a result to the browser.When I was looking at the callback mechanism, I suddenly thought that Ajax was an asynchronous call, and that I was writing a synchronous call (not related to the callback mechanism), so I wanted to summarize last week's understanding of synchronous, asynchronous,

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_ se