Java Thread Synchronization and Mutual Exclusion: Lifting the veil of multi-threaded programming and embracing the challenges of a concurrent world

php editor Yuzai launches the latest article, which deeply discusses Java thread synchronization and mutual exclusion, unlocks the secrets of multi-threaded programming, and challenges the excitement of the concurrent world. This article will unveil multi-threaded programming for you, take you into the wonderful world of concurrent programming, and explore the challenges and fun.

The problem of thread synchronization and mutual exclusion means that when multiple threads access shared resources at the same time, it may lead to data inconsistency or program crash. To solve this problem, Java provides a variety of synchronization mechanisms, including:

• synchronized keyword: The synchronized keyword can be used to modify a method or code block. When a thread enters a synchronized method or code block, other threads will not be able to enter the method or code block until the Until the thread completes execution and releases the lock.

public class Counter {
private int count = 0;

public synchronized void increment() {
count++;
}

public synchronized int getCount() {
return count;
}
}

• ReentrantLock class: The ReentrantLock class is a reentrant lock that allows a thread to acquire the same lock multiple times. When a thread acquires a ReentrantLock lock, other threads will not be able to acquire the lock until the thread releases the lock.

public class Counter {
private int count = 0;
private ReentrantLock lock = new ReentrantLock();

public void increment() {
lock.lock();
try {
count++;
} finally {
lock.unlock();
}
}

public int getCount() {
lock.lock();
try {
return count;
} finally {
lock.unlock();
}
}
}

• Semaphore class: The Semaphore class is a semaphore, which can be used to control the number of threads accessing shared resources at the same time. When a thread acquires a Semaphore lock, other threads will not be able to acquire the lock until the thread releases the lock.

public class Counter {
private int count = 0;
private Semaphore semaphore = new Semaphore(1);

public void increment() {
semaphore.acquire();
try {
count++;
} finally {
semaphore.release();
}
}

public int getCount() {
semaphore.acquire();
try {
return count;
} finally {
semaphore.release();
}
}
}

In addition to the above synchronization mechanisms, Java also provides some other synchronization mechanisms, including:

• volatile keyword: The volatile keyword can be used to modify variables. When a thread modifies a volatile variable, other threads will immediately see the modification.

• Atomic class: The Atomic class provides some atomic operations that can be safely performed between multiple threads.

• LockSupport class: The LockSupport class provides some methods that can be used to pause and wake up threads.

Thread synchronization and mutual exclusion are an important issue in multi-threaded programming. Mastering this knowledge can help you write safer and more reliable multi-threaded programs.

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