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In one work, there was a small accident. The result of a redis write and read method was always different from what was expected. After careful consideration, it was found that because all nodes in the cluster use shared caches and queues, resource competition may occur among nodes in some scenarios, There may be a "thread insecurity probl ...

Fair lock and unfair lock Fair lock It refers to that multiple threads acquire locks according to the order of applying for locks, and follow the principle of first come, first serve. Its implementation can use queues. Unfair lock The method of multiple threads acquiring locks is not in the order of applying for locks. The thread that ap ...

environment The process in php is completed in the form of extension. Through these extensions, we can easily complete a series of actions of the process. pcntl extension: the main process extension, which completes the process creation in the waiting operation. posix extension: complete the general api of posix compatible machine, such as ob ...

Java learning record day 18 Since this slag is converted to Java at the front end, the selection of editor is directly used webstorm With the company idea Some of the following knowledge will be learned from the boss Liao Xuefeng's blog Learning objectives What is multithreading and how to use it? Learning content Java multithreadi ...

  ThreadLocal is jdk1 2, which is used to provide local variables in the thread. Unlike ordinary variables, thread local variables are bound to threads, and each thread has its own independent variable container. Thread local variables play a role in the life cycle of a thread to reduce the transmission complexity of common variables between m ...

introduce When you read this article, you need to understand the principle of AQS first, because this article does not involve the explanation of the internal principle of AQS. CountDownLatch is a synchronization assistant. When multiple threads execute tasks, we need to wait for the thread to complete the execution before executing the ...

What is AQS? In Lock, a synchronization queue AQS is used. Its full name is AbstractQueuedSynchronizer. It is a synchronization tool and the core component used by Lock to realize thread synchronization. java. util. Most of the tools in concurrent are implemented through AQS. The core idea of AQS is that if the requested shared resource is idl ...

In Java, there are many scenarios for generating random numbers, so in this article, we will take an inventory of the four ways to generate random numbers, the differences between them and the corresponding scenarios of each way. 1.Random Random class was born in JDK 1.0. The random number it generates is pseudo-random number, that is, regula ...

Same series of articles python crawler + pygal interactive visual crawling University QS ranking_ m0_61168705 blog - CSDN bloghttps://blog.csdn.net/m0_61168705/article/details/122699759?spm=1001.2014.3001.5501 Article catalogue catalogue Same series of articles Article catalogue preface 1, Imported Libraries 2, Rewrite code ren ...

Synchronized & volatile of concurrent programming concept Locks are often mentioned in concurrent programming. Adding locks ensures the data security of multiple threads. Each object in java can be used as a lock. There are three specific manifestations: For common synchronization methods, the lock is the current instance object; F ...