kiosk lock

Process Lock: Why should have process lock: If now have a printer, QQ to use printer, Word document also want to use printer, if not using process lock, may cause some problems, such as QQ task Print to half, word inserted, so print out the result is the respective half. Process lock creation and use:

Redis Lock Structure and redis lockSingle thread and isolation Redis uses a single thread to execute transactions. transactions are run in a serial manner. That is to say, the execution of a single command in Redis and the execution of a transaction are thread-safe and will not affect each other, isolation. In multi-threaded programming, be careful when accessing shared resources: import threadingnum = 1lock = threading.Lock()def change_num(): glob

Original works, from "Deep Blue Blog" blog, dark blue blog:http://blog.csdn.net/huangyanlong/article/details/46876961RAC Production library kill lock table session killed state processing occursEnvironment:Operating system: CentOS 6.4 64BITDatabase: Oracle RAC 11.2.0.4 R2 64bitIn a project, when you perform a big data extraction task, the extraction error occurs and the large table needs to be re-extracted. The insert operation is canceled and then th

first, the encryption algorithm in AndroidThe previous article has introduced the Android System lock screen cipher algorithm principle, here to summarize said:The first type: input cipher algorithmEnter the plaintext password + The salt value of the device, then manipulate MD5 and SHA1 after the conversion to hex value for stitching, the final encryption information is saved to the local directory:/data/system/password.keyThe second type: gesture cip

The above discusses the mutex and conditional variables used for thread synchronization, this article will discuss the use of read and write locks and spin locks , and give the corresponding code and considerations, the relevant code can also be downloaded on my GitHub . read/write lock The mutex is either locked or unlocked, and only one thread can lock it at a time, while a read-write

Recently, I moved from Beijing to Shenzhen. Except for the weather, the other jobs are similar and work is similar! To commemorate your migration. ----- Digress Reprinted to indicate the source: Http://blog.csdn.net/wdaming1986/article/details/8837023 Well, let's get down to the truth and talk about the lock screen. In fact, making the lock screen into the APK form will cause many problems and cause unneces

Android app. Samsung i9000 series tutorial (2). Engineering Code, network lock and Lock three keys Papaya 20110401 I. Engineering Code The project code provided by i9000 is very useful, as follows.(The content is organized on the network. The original author is unknown) Dial Input * #0 * # mobile phone test (recommended purchase test)Line 1 red green blue (primary color test)Line 2 melody vibrate dimming)Li

When using Hibernate, we may encounter multiple users simultaneously modifying the same data, which may cause dirty data and data inconsistency. To avoid data loss during update, Hibernate uses a lock mechanism.Hibernate provides two lock mechanisms: Pessimistic lock and optimistic lock.Pessimistic lock: when data is l

Hibernate pessimistic lock and optimistic lock instance details, hibernate instance details This article mainly focuses on Hibernate pessimistic locks and optimistic locks. The details are as follows.Pessimistic lock Pessimistic locks are usually implemented by the database mechanism. during the entire process, data is locked (during query) as long as the transa

Java concurrent packet source code learning-AQS framework (2) CLH lock queue and spin lock, aqsclh As mentioned in the previous article, AQS is based onCLH lock queueSo what is CLH lock queue? complexity is complicated, simple, and simple. The so-called greatest truths are simple: CLH

make instance-level data thread safe. This can be done as follows: Public class democlass{ publicsynchronizedvoid DemoMethod () {}}Or Public class democlass{ publicvoid DemoMethod () { synchronized (this) { //Otherthread safe code }} } Or Public class democlass{ privatefinalnew Object (); Public void DemoMethod () { synchronized (lock) { //other Thread safe Code }}

This article focuses on the lock (lock) used for multithreading synchronization in C # as a research object. Because you want to display the results more intuitively, so, in doing the demo, the multi-threaded through the event UI code also written out, left as a memo and share it.In fact, multi-threaded synchronization, the use of synchronous locking method used several times, today inadvertently see MSDN,

We all know that there is a thread synchronization problem when multithreading concurrency, usually using the lock keyword to handle.The result of the lock keyword is as follows:Object locker=new pbject ();Lock (Locker) { ...}To understand this lock first we need to know that lo