Concurrent Package and MultithReaded Control in Java Class Libraries in Java Class Library
Concurrent bag and multi -threaded control in the Java class library
In Java's Class library, the Concurrent package provides us with a set of powerful tools to control multi -threaded.In concurrent programming, multi -threaded control is a very important task because it can improve the performance and response ability of the program.This article will introduce the Concurrent package in the Java class library and how to use these tools to control the multi -threaded thread.
1. Introduction to packet
The packets in Java provide a series of classes and interfaces for managing and controlling multi -threaded.These tools can help us achieve synchronization, collaboration and mutual exclusion operations between threads.The main features of the Concurrent package include thread security, high efficiency and scalability.
2. Locks (locks)
Locks are the basic mechanism to control multi -threaded access to shared resources.The concurrent packets in the Java library provide a variety of types of locks, such as Mutex, ReentRantreamwriteLock and Condition.The following is a sample code that uses mutually locking:
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
public class MyThread implements Runnable {
private Lock lock = new ReentrantLock();
public void run() {
lock.lock (); // Get the lock
try {
// The code executed by the thread
} finally {
lock.unlock (); // Release the lock
}
}
}
3. Symptom (SEMAPHORES)
Symptoms are a mechanism that controls the number of access to shared resources.The SEMAPHORE class in the Java class library allows us to specify a certain number of licenses. The thread can obtain the license through the ACquire () method and release the license through the release () method.The following is an example code that uses the semaphore:
import java.util.concurrent.Semaphore;
public class MyThread implements Runnable {
private static int MAX_THREADS = 5;
private static Semaphore semaphore = new Semaphore(MAX_THREADS);
public void run() {
try {
semaphore.acquire (); // Get the license
// The code executed by the thread
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
semaphore.release (); // Release the license
}
}
}
4. The fence (countdownlatch)
The fence is a mechanism that is waiting for all threads to continue.The Countdownlatch class in the Java class library allows the main thread to wait for the specified number of threads to be completed before continuing.Below is an example code using the fence:
import java.util.concurrent.CountDownLatch;
public class MyThread implements Runnable {
private static int NUM_THREADS = 5;
private static CountDownLatch latch = new CountDownLatch(NUM_THREADS);
public void run() {
try {
// The code executed by the thread
} finally {
LATCH.COUNTDOWN (); // The number of threads is reduced after completing the task
}
}
public static void main(String[] args) throws InterruptedException {
for (int i = 0; i < NUM_THREADS; i++) {
new Thread(new MyThread()).start();
}
latch.await (); // The main thread is waiting for all threads to complete
System.out.println("All threads completed.");
}
}
5. Cyclicbarrier
The cycle fence is similar to the fence, but it can perform a certain operation when each thread reaches the fence.The CyclicBarrier class in the Java library allows us to specify the action to be performed when the fence is reached.Below is a sample code using a circular fence:
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
public class MyThread implements Runnable {
private static int NUM_THREADS = 5;
private static CyclicBarrier barrier = new CyclicBarrier(NUM_THREADS, () -> {
// All threads are performed after the fence is reached
System.out.println("All threads reached the barrier.");
});
public void run() {
try {
// The code executed by the thread
barrier.await (); // Wait for other threads to reach the fence
} catch (InterruptedException | BrokenBarrierException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
for (int i = 0; i < NUM_THREADS; i++) {
new Thread(new MyThread()).start();
}
}
}
This article introduces the Concurrent package in the Java class library and how to use the tools to control the multi -thread.Locks, semaphores, fences, and circulating fences are several commonly used multi -threaded control mechanisms. They can help us avoid thread conflict, realize resource sharing and thread synchronization.Mastering these tools can make us write high -efficiency and reliable concurrency procedures.
