lasso lock

The last tool in the lock is introduced from this section: read-write Lock (Readwritelock).Reentrantlock implements a standard mutex, which is the notion that only one thread can hold a lock at a time, or the so-called exclusive lock. This feature has been emphasized in the previous chapters. Obviously this feature red

Before Java5.0, only synchronized (built-in locks) and volatile. The display lock Reentrantlock is introduced after Java5.0. Reentrantlock Overview Reentrantlock is a reentrant lock, unlike a built-in lock, which needs to be displayed for lock and unlock every time it is used, and provides more advanced features: Fai

MySQL lock usage-row-Level Lock is the smallest lock in MySQL, which can greatly reduce database operation conflicts. However, the smaller the granularity, the higher the implementation cost. The MYISAM engine only supports table-level locks, while the INNODB Engine supports row-level locks. The following content is also for INNODB row-level locks. Row-level lock

Pessimistic lock Introduction (encyclopedia): A pessimistic lock, as its name implies, is conservative in that the data is modified by the outside world (including other transactions of the system, as well as transactions from the external system), so that the data is locked during the entire process of processing. Pessimistic lock implementation, often rely on t

Tags: name water hang Process Control point for SNAP isolation level(in order to facilitate, the English keywords are used in lowercase, the relevant knowledge points will be introduced briefly, strive to be able to read independently)At the beginning of the article I will first introduce the following knowledge points required in this article: Knowledge of InnoDB clustered index (clustered index) and non-clustered index (two-level index, nonclustered index) Isolation level for INNO

[Guide: The basic theory of locks used in various large databases is consistent, but there are differences in the implementation. SQL Server emphasizes that the locks are managed by the system. When the user has a SQL request, the system analyzes the request, automatically in satisfying the lock condition and the system performance for the database with the appropriate lock, while the systems are often auto

A recently maintained network server encountered performance problems, so it made major changes to the original program framework. Most of the changes are the thread working mode and data transmission mode. The final result is to change the lock usage mode. After some improvement, the GMB Nic can basically work at full speed. After the performance was up to standard, I was wondering if I could use a more lightweight

Mainly talk about the performance of the lock and some other theoretical knowledge, the main source of the content is "Java Concurrency in Practice", combined with their own understanding and practical application of the lock mechanism to a small summary.One of the first things to emphasize is that all locks (including built-in locks and advanced locks) are performance-intensive, that is, in high concurrenc

Mainly talk about the performance of the lock and some other theoretical knowledge, the main source of the content is "Java Concurrency in Practice", combined with their own understanding and practical application of the lock mechanism to a small summary.One of the first things to emphasize is that all locks (including built-in locks and advanced locks) are performance-intensive, that is, in high concurrenc

Reentrantlock Source Analysis 1--get unfair lock and fair lock () The most common way: View Code 1, for Reentrantlock need to master the following Reentrantlock creation (Fair lock/non-fair lock) Lock: Lock () Unlock: Unlock () Fi

Previous continuedA murder caused by a lock-free message queue: How to be a real programmer? (a)--ground: CauseA murder caused by a lock-free message queue: How to be a real programmer? (b)--month: Spin lockParallel spaceIn the copy of the above line I stopped first, is considered to occupy a position, although I know how to write, but the feeling is still very messy.I suddenly thought, since so tangled, so

Prior to Java5.0, only synchronized (built-in lock) and volatile. The display lock Reentrantlock is introduced after Java5.0. Reentrantlock OverviewThe Reentrantlock is a reentrant lock, which differs from the built-in lock, which needs to display the lock and unlock fo

Spin locks and mutex are two important concepts in concurrent programming. They are mainly used to lock shared resources to prevent Concurrent Data Access and ensure data consistency. But they also have some differences. This article mainly introduces these differences and describes when to use the spin lock and when to use the mutex lock. Theoretical Basis T

Why locks (concurrency control) are required. In a multiuser environment, multiple users may update the same record at the same time, which can create a conflict. This is the famous concurrency problem. Typical conflicts are:(1) Missing update: One transaction update overwrites the update result of other transactions, that is, the so-called update is lost. For example: User A changes the value from 6 to 2, and User B changes the value from 2 to 6, then user a loses his update. (2) Dirty read:

Oracle lock 1: DML lockDML lock, also known as data lock, is used to ensure data integrity when multiple users operate on data. DML lock prevents conflicting DML and DDL operations at the same time. DML Locks include Row Locks (TX) and Table Locks (TM). Different DML operations will automatically request the correspond

This article from: http://blog.163.com/hbu_lijian/blog/static/126129153201261722410353/ Kernel synchronization measures (for Linux kernel) To avoid concurrency and prevent competition. The kernel provides a set of Synchronization Methods to protect shared data. Our focus is not to introduce the detailed usage of these methods, but to emphasize the difference between these methods and them.The synchronization mechanism used in Linux has been continuously improved since 2.0 to 2.6. From the initia

A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (2) -- month: spin lock, queue spinPrefix A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (1) -- location: Cause A bloodcase caused by a lock-free Message Queue: how to be a real programmer? (2) -- month: spin lo

I. The background of the spin lock proposedBecause some resources in a multiprocessor system environment are limited and sometimes require mutually exclusive access (mutual exclusion), a lock mechanism is introduced, and only the process that acquires the lock can obtain access to the resource. that is, only one process can acquire a

One: OverviewCompared with other databases, MySQL's locking mechanism is relatively simple, and its most notable feature is that different storage engines support different locking mechanisms. For example, the MyISAM and memory storage engines use table-level locks (table-level locking), InnoDB storage engines support row-level locks (row-level locking) and table-level locks, but row-level locks are used by default.MySQL main two types of lock charact

Description: 1, personal technology is not a drop, also did not write threads in the project, the following are all based on their own understanding of the written. Therefore, only for reference and hope to point out the different views. 2, actually want to put the code of GitHub posted out, but still recommended in the beginner you write more personally, it is not posted out.I. BASIC INSTRUCTIONSClass, Object: ... (Don't know what to say, imaginative achievement here inexpressible >. Class lock