What is io:(input/output): input and output.IO device: a device that communicates with a computer.input device: microphone, scanner, keyboard, mouse and so on.output Devices: monitors, printers, projectors, headphones, audio, etc.Why does the program need IO ?Case 1: Play game operation, score higher, store game information.In this case, you need to store the data in the game and only store it in the file.C
, directly submit the command + user buffer to the kernel driver, and then return immediately. At this time, the user thread can continue to run and do other things.
When you want to know the command completion status, you can use getqueuedcompletionstatus to obtain the completed request and data.
Therefore, you can submit a large number of IO requests first, and then process and return them slowly.
The reason why iocp is more efficient than epoll is
Basic Application of socket. io tutorial (2) socket. io tutorial
Preface
Socket. IO supports timely, bidirectional, and event-based communication. It can work on every platform, every browser, and every device, with the same reliability and speed.
Real-time analysis: pushes data to clients, which are expressed as real-time counters, charts, or log customers.
The use of MPI-2 parallel IO, mpi-2 parallel io
The MPI program needs to use parallel IO to operate files, but du Niang does not find many methods to use parallel IO functions. Finally, I found some useful papers on zhiwang. After reading them, I felt very open.
MPI-1 operations on files are carried out by using the fu
Java asynchronous IO and java asynchronous io
The key points of the new asynchronous functions are some subsets of the Channel class. The Channel needs to be switched to a background process when processing IO operations. You can use this function to access large, time-consuming operations or other similar instances.Here, we will only explain the AsynchronousFile
Server performance indicators
As a network server program, performance is always the first indicator. Performance can be defined as the number of tasks that can be processed in a given hardware condition and time. The server design that maximizes the use of hardware performance is a good design.A well-designed server should also consider the average service. For each client, the server should provide the average service to each client, so that a client cannot be served for a long time and the se
Objective:
In general operations work often encounter such a scenario, the server's IO load is very high (util in iostat), but unable to quickly locate the IO load source process and source files resulting in the inability to make the appropriate policy to solve the problem.
This phenomenon is more common on MySQL, and before 5.6 (Performance_schema provides IO
One, I/O ports
Port is the address of a register that can be accessed directly by the CPU in an interface circuit. Almost every peripheral is done by reading and writing registers on the device. The CPU sends commands to the registers in the interface circuit through these address ports, reading status and transmitting data. Peripheral registers, also known as "I/O ports", typically include three categories of control registers, state registers, and data registers, and the registers of a periph
Performance Tuning: IO consumption analysis, performance tuning io consumption
Performance Tuning-> how to analyze io consumption
Reprinted please indicate the source: http://blog.csdn.net/supera_li/article/details/45225077For more information about the performance tuning series, see.Performance Optimization: Analysis of CPU consumptionPerformance Optimization:
1, event channel model. The event channel is the prototype of asynchronous IO.2, io mode, one IO call will go through two stages. First, wait for the data phase, the data from the network or disk read to the system kernel (kennel) Two, the data from the kernel copy into the process.Based on these two phases, the Linux system generates five network mode scenarios.
Serialization, deserialization, and IO serialization of Java-io stream objects
Basic serialization operations
1. Object serialization means to convert an Object into a byte sequence, and vice versa.
2. The ObjectOutputStream and writeObject methods are used to write objects to the output stream;
The deserialization stream (ObjectInputStream). The readObject method is used to read objects from the input s
JDK source code reading (1) _ introduction + java. io, jdkjava. io
1. IntroductionFor this forum, I will take a Java 8 source code reading note. Some java packages that are widely used in java Web are intensively read with comments attached. Compare and analyze confusing knowledge points.The source code sequence of Intensive Reading is as follows:(1) Part 1: This part is the most common java development pac
Java io stream learning and Java io stream
I have carefully studied Java I/O streams in recent days. I was planning to watch videos and learn through videos. However, I found that videos are not easy to understand, so I learned the Java io stream through Baidu and api documentation.
Io streams can be classified into t
Java BASICS (12) IO input and output, java basics io Input and OutputI. IO Overview 1. IO concepts
IO: I represents Input; O represents Output.
In Java, IO is input and output based on a stream. AllSerializing data(SAVE) write to
ObjectiveStandard C provides file-related IO functions, except that the standard error output is unbuffered (the error message can be displayed as soon as possible), all terminal-related are row buffers, and the rest are fully buffered.We can use SETBUF,SETVBUF to change the buffer type of the specified stream.Prototype: void Char *buf); int Char int mode, size_t size); Successful return 0, failure not 0The function is used at a glance, and when t
Java IO _ IO operation instance notes
Objectives of this chapter:Master Java data operation instances
Example 1: Addition
Example 2: menu display
3. Knowledge Used in this instance
1. Standard Format of keyboard input data2. date conversion and use of packaging classes3. class design ideas.
4. Details
Sample Code:
Import Java. io. *; public class execdemo01 {publ
Pipelines are used to communicate between processes on the same machine or between different machines in the same network. You can use anonymous pipelines and named pipelines in. net. Pipeline-related classes are in the system. Io. Pipes namespace .. The essence of pipelines in. NET is the encapsulation of MPs queue-related functions in Windows APIs.
Use an anonymous pipeline to communicate with Parent and Child processes:
An anonymous pipeline is a t
there are many connections, there will be insufficient resources.
Another efficient method is to store a socket connection on the server.And then Round-Robin the list. If a socket port is read (read-only), the corresponding read operation of the socket connection is called.When data is writable on the socket port (write-ready), the corresponding write operation of the socket connection is called. If the socket connection of a port is interrupted, the corresponding destructor is called to close
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