volatile int

Wait Queue: In Linux driver programming, waiting queues can be used to implement blocking of processes. The wait queue can be thought of as a container for the save process, and the process is placed in a wait queue when the process is

The simplest bootloader steps to write:1. Initialization hardware: Close watchdog, set clock, set SDRAM, initialize NAND FLASH2. If the bootloader is larger, reposition it to SDRAM3. Read the kernel from NAND flash to SDRAM4. Set "parameters to pass

The basic way to use GDB is not to mention it here.command behavior for loading core files:DGB EXE CoreFor exampleGdB./testall./core.2345One of the most important commands is where, which is like WinDbg's command!analyze-vI simulated a few crash

Brief introductionThe volatile keyword guarantees that in a multithreaded environment, modified variables are synchronized to main memory immediately after modification, so that the thread modifies the variable to be visible to all other threads,

Prior to JDK 5, the Java language was guaranteed to be synchronized by the Synchronized keyword, which would result in a lock (later chapters will also talk about locks).The lock mechanism has the following issues:(1) Under the multi-thread

Today, I read an article on the Internet, talking about the volatile feature to use 1000 threads constantly accumulating numbers, each time the cumulative 1, to the final value is not 1000.The article is a bit misunderstood by others, but in the

Volatile in Java does not guarantee thread safety (example explained)Reprinted 2017-09-04 Think-007 I want to commentThe following small series to bring you a piece of Java in the volatile can not guarantee thread safety (the example explained).

Previous Blog post Java Concurrency programming 3_ thread synchronization synchronized keyword in Java to ensure that thread synchronization of the keyword synchronized, in fact, Java also has a weak synchronization mechanism volatile. The volatile

AQS concurrent and a very important top-level lock class, often used more is reentrantlock,However, the realization of Reentrantlock relies on AbstractqueuedsynchronizerIn the upper Countdownlatch, semaphore and so on is not based on Reentrantlock

Write in frontThis is the Java multi-threaded sentiment of the second blog, mainly on the Java level of some support for concurrency. The first blog address is:http://zhangfengzhe.blog.51cto.com/8855103/1607712 The next blog will introduce the

(i) Mutual exclusionMutex, or atomicity. Atoms, refers to the smallest matter, the specific non-division of the.In CPU operation, the time slice of multi-threading is executed, and one block executes, which satisfies the atomicity of mutex.Ways to

Two cyanPersonal site: zhangerqing.cn email: [Email protected] Weibo: HTTP://WEIBO.COM/XTFGGEFAtomic IntroductionThe atomic package is another Java package specifically designed for thread safety under Java.util.concurrent and contains multiple

The struct file struct is defined in the/linux/include/linux/fs.h (Linux 2.6.11 kernel), and its prototype is:struct File {        /** Fu_list becomes invalid after file_free are called and queued via* Fu_rcuhead for RCU freeing         */Union

ObjectiveIn high-concurrency applications, the most critical problem is secure access to shared variables, usually through locking, such as synchronized, lock to ensure atomicity, or in some applications, with voliate to ensure the visibility of

IntroductionAs we said in the previous article, volatile is guaranteed visibility, ordering, and "partial" atomicity through the lock command. However, in most concurrency problems, it is necessary to ensure the atomicity of the operation, volatile

XV6 Code Reading report-TOPIC3@ Xiaojiannan 20111013223 XV6 Code Reading report-TOPIC3 1. Order 2. Context Switches 2.1 Defs.h 2.2 Swtch. S 3. Process scheduling 4. Piping 5.

java.util.concurrent.atomic Atomic Operation Class Pack=====java.util.concurrent.atomic Atomic Operation Class PackThis package provides a set of atomic variable classes. The basic feature is that in a multithreaded environment, when there are

Why is the use of volatile lower than the cost of synchronization? The cost of synchronization is mainly determined by its coverage, and if you can reduce the coverage of synchronization, you can significantly improve program performance. And

This article focuses on the driver architecture and writing under the Linux kernel, as well as the introduction of simple-to-use driver applications under Linux :First we look directly at the simple application that uses the drive:#include #include

Http://blog.chinaunix.net/uid-1829236-id-3182279.htmlWhat is the user state, what is the kernel state, these two basic concepts have been understood not very clearly, the root cause of the personal feel is because most of the time we write programs