Shulou(Shulou.com)05/31 Report--

This article introduces the knowledge of "how to communicate between processes of the linux general operating system". In the operation of actual cases, many people will encounter such a dilemma, so let the editor lead you to learn how to deal with these situations. I hope you can read it carefully and be able to achieve something!

When each task is running, it occupies the most reasonable available resources in the processor, and when each task is running, it is an independent memory allocation and independent processor data operation. So suppose I have two tasks running in the system at the same time, Task 1 and Task 2. Suppose Task 1 is a data acquisition task of external hardware, such as a task pressed by a scan button, which runs every other system "heartbeat". Task 2 is a task that processes the key values in Task 1. There is a question here, as we said earlier, when Task 1 is not running, its memory and processor resources may be reclaimed, and where should the resulting keystroke scan data be stored, or in other words, how should Task 2 know which keys have been pressed? At this point, we are almost certain that there must be one or more solutions that allow two unrelated tasks to interact with each other. We call the mechanism of data exchange between these processes "interprocess communication", abbreviated IPC (Inter-Process Communication).

Let's take the standard Linux operating system as an example, the communication between processes is mainly in the following ways:

Piping (pipe)

Named Pipeline (named pipe)

Semaphore (semophore)

Message queuing (message queue)

Signal (sinal)

Shared memory (shared memory)

Socket (socket)

# pipe: a pipe is a half-duplex mode of communication in which data can only flow in one direction and can only be used between related processes. The genetic relationship of a process usually refers to the relationship between a father and a child process.

# named pipe: a named pipeline is also a half-duplex communication method, but it allows communication between unrelated processes.

# semaphore (semophore): a semaphore is a counter that can be used to control the access of multiple processes to shared resources. It is often used as a locking mechanism to prevent other processes from accessing a shared resource when it is being accessed. Therefore, it is mainly used as a means of synchronization between processes and between different threads within the same process.

# message queuing (message queue): message queues are linked lists of messages, stored in the kernel and identified by message queue identifiers. Message queuing overcomes the shortcomings of less signal transmission information, pipeline can only carry unformatted byte stream and limited buffer size.

# sinal: a signal is a more complex form of communication that notifies the receiving process that an event has occurred.

# shared memory (shared memory): shared memory maps a piece of memory that can be accessed by other processes. This shared memory is created by one process, but can be accessed by multiple processes. Shared memory is the fastest IPC mode, and it is specially designed for other inter-process communication modes to run inefficiently. It is often used in conjunction with other communication mechanisms, such as signal two, to achieve synchronization and communication between processes.

# socket: socket is also an inter-process communication mechanism. Unlike other communication mechanisms, it can be used for different and inter-process communication.

This is the end of the content of "how to communicate between processes in the linux General operating system". Thank you for your reading. If you want to know more about the industry, you can follow the website, the editor will output more high-quality practical articles for you!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.