Programmer Group

Catalogue of series articles 1: Computer model & detailed explanation of volatile keyword 2: Lock system in java 3: synchronized keyword explanation 5: Atomic atomic class and Unsafe magic class preface It can be seen from the previous article. volatile keyword and synchronize keyword can help us solve the problem of data sec ...

Thread pool If too many threads are created in the JVM, the system may run out of resources due to excessive memory consumption or "excessive switching". In order to solve this problem, the first thought is pooling, so there is the concept of thread pool. The core logic of the thread pool is to create several threads in advanc ...

JDK1.7 First, the data is stored section by section, and then each section of data is equipped with a lock. When a thread occupies the lock to access one section of data, the data of other sections can also be accessed by other threads. ConcurrentHashMap is composed of Segment array structure and HashEntry array structure. Segment is a r ...

start() and run() explain The start() method is used to start a thread. When a thread calls the start() method, it means that the thread enters the ready state and waits for thread scheduling The run() method is just a common method of the Thread class, which holds the work that the Thread needs to complete] difference The start() method i ...

5. Routing messages In the previous example, we created and used a single actor, and an actor can only process one message at the same time, which does not give play to the advantages of akka parallel computing. We hope to process messages in parallel, just like kafka's consumer. This requires the use of routing to akka. Routing is the same a ...

1, Atomic integer JUC also provided: AtomicBooleanAtomicIntegerAtomicLong Let's take AtomicInteger as an example to understand the common API s. All operations are atomic. Self increasing: incrementAndGet(): Auto increment and get, equivalent to + + igetAndIncrement(): get and auto increment, equivalent to i++ Self subtraction dec ...

2, Collection class unsafe 2.1ArrayList thread is unsafe 2.1.1 example Single thread public class NotSafeDemo { //Single thread is safe public static void main(String[] args) { List<String> list = Arrays.asList("a", "b", "c"); list.forEach(System.out::println); } } a b c Multithreading public class NotS ...

1. Atominc Atom Package There are 12 classes in the Atomic package, and there are four ways to update atoms: the basic type of atomic update, the array, the reference, and the field. The classes in the Atomic package are basically wrapper classes implemented using Unsafe. Basic Classes: AtomicInteger, AtomicLong, AtomicBoolean Reference type ...

preface In the previous two articles Synchronization queue for AQS,Conditional queue This article is to take a look at the three main concurrency tool classes in JUC: countDownLatch, cyclicBarrier and semaphore. This article will not expand from the perspective of source code as in the previous two articles, but take a look at the usage me ...

Hello, I'm Xiao Hei, a migrant worker who lives on the Internet. Runnable When creating a Thread, you can use the new Thread(Runnable) method to encapsulate the task code in the run() method of Runnable, submit the Runnable to the Thread as a task, or use the execute(Runnable) method of the Thread pool for processing. public class RunnableDe ...