what semaphore in linux with example

POSIX semaphores are real-time extensions that are part of the POSIX standard system interface definition. The XSI IPC defined in the SUS (Single UNIX specification) specification also defines the system interface that people commonly refer to as

SemaphoresWhen we use thread operations to write programs in a multi-user system, multi-process system, or a mixed system, we often find that we have a piece of critical code, here, we need to ensure that a process (or thread execution) needs to

SemaphoresWhen we use thread operations to write programs in a multi-user system, multi-process system, or a mixed system, we often find that we have a piece of critical code, here, we need to ensure that a process (or thread execution) needs to

"Semaphores are used in multi-threaded multitasking, where one thread completes an action by telling another thread about the semaphore, and the other thread is doing some action (where everyone is blocking when they are semtake). The mutex is used

Mutex is a key. When a person takes the key, they can enter a room. When they come out, the key is handed over to the first in the queue. Generally, this method is used to serialize the access to the critical section code to ensure that the Code is

1. What is semaphore?To prevent a series of problems that arise from the simultaneous access of multiple programs to a shared resource, we need a method that can be authorized by generating and using tokens, and at any one time there can be only one

This article will describe the mechanism of a communication between processes-the semaphore. Note: Please do not confuse it with the previously mentioned signal, the signal and the semaphore are different two kinds of things. For more information

Transferred from: http://blog.csdn.net/goodluckwhh/article/details/9006065Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.Directory (?) [-] A signal volume The concept of

The signal volume of the Linux kernel is the same as the concept and principle of the IPC-mechanism semaphore of the user-State System V, but it is never possible to use it outside the kernel, so he has nothing to do with the IPC mechanism semaphore

"The semaphore is synchronized with multi-threaded multitasking, and one thread completes an action by telling the other thread that the other thread is going to do some action (where everyone is blocking when they are semtake)." The mutex is used