It is used to mark a certain block of code. How the synchronized operator worksLet's get to know a new keyword: synchronized. You don't need to do anything to create a mutex: it's already built into the Object class, which means that every object in Java has one. If an object's mutex is in the hands of one thread, other threads can't work with the object. This way you end up having a good and fruitful discussion.Įssentially, the ball is a mutex. But because you're seeing each other for the first time, in order to not constantly interrupt each other and fly into a rage, you use a 'talking ball': only the person with the ball can speak. Taking turns, you need to express your ideas and discuss something. Here's an example from life: imagine that you and 10 other strangers are participating in an exercise. The other threads must wait until object A's mutex is released. If Thread-1 acquires object A's mutex, the other threads won't be able to access and modify the object. The purpose of a mutex is to provide a mechanism so that only one thread has access to an object at a certain time. That's why they introduced a special concept, the mutex (mutual exclusion), to multithreaded programming. The result, as you can see, is depressing. What other threads have or have not already managed to write doesn't matter. If the thread scheduler allocats time to Thread-1, then it instantly writes everything to the console. ![]() The reason lies in the fact that the threads are working with a shared resource (the console) without coordinating their actions with each other. In a recent lesson, we saw an example of where this leads. The threads are unaware of each other's existence, so they simply write everything they can in the time allotted to them by the thread scheduler. In this case, the file or console becomes a shared resource. Imagine multiple threads writing text to the same place, for example, to a text file or the console. Multiple threads can actively work with and modify the same data set. In real programs, such situations are rare. One performed a calculation, a second slept, and a third displayed something on the console, but they didn't interact. ![]() In previous lessons, our threads lived and worked separately from each other. Thread synchronization has a similar meaning: it's an arrangement in which threads interact with each other. For example, a smartphone and computer can be synchronized with a Google account, and a website account can be synced with social network accounts so you can use them to sign in. Outside of the programming domain, it implies an arrangement that allows two devices or programs to work together. Personally I can think of ways to tackle all this but I'm wondering if there are any well known patterns, literature or best practices that I could refer to.Hi! Today we'll continue to consider the features of multithreaded programming and talk about thread synchronization. If you're going for a real-time sync (ie an update in one system immediately triggers an update to the other system) how to handle divergence over time due to bugs or system crashes.If you're going for a once-every-N-hours sync, how to deal with conflicts where the same record changes at more-or-less the same time in both systems. ![]()
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