Halo-DistributedLock

halo-distributedlock is a simple and reliable distributed lock implementation. It is designed to help you learn the principles of distributed locking and provides a lightweight solution for your production environment (assuming you are using single instance Redis). Whether you're a beginner or an experienced developer, It's worth to take a look at.

Features

• Supports distributed lock, distributed unlock operations with a singleton Redis.
• Supports lock leasing, lock blocking and lock reentrant.

Quick Start

Step one: Add maven dependency

<dependency>
    <groupId>site.hellooo</groupId>
    <artifactId>halo-distributedlock-core</artifactId>
    <version>>${halo-distributedlock.version}</version>
</dependency>

Step two: lock your resources with Lock.lock()

public class SingleProcessMultiThreadContention {
    public static void main(String[] args) {
        lockCompetition();
    }

    public static void lockCompetition() {
        long start = System.currentTimeMillis();

        ConfigReader.RedisConfig redisConfig = ConfigReader.redis();
        String host = redisConfig.getHost();
        int port = redisConfig.getPort();

        JedisPool jedisPool = new JedisPool(host, port);
        for (int i = 0; i < 500; i++) {
            final int threadNumber = i;
            Thread thread = new Thread(() -> {
                Thread.currentThread().setName("locking_thread_" + threadNumber);

                Lock lock = new ReentrantDistributedLockBuilder()
                        .lockOptions(LockOptions.ofDefault())
                        .jedisPool(jedisPool)
                        .lockTarget("my_lock")
                        .build();

                System.out.println("process [" + ProcessUtils.getProcessId() + "] thread [" + Thread.currentThread().getName() + "] is getting lock");
                lock.lock();
                System.out.println("process [" + ProcessUtils.getProcessId() + "] thread [" + Thread.currentThread().getName() + "] got lock");
                lock.unlock();
                System.out.println("process [" + ProcessUtils.getProcessId() + "] thread [" + Thread.currentThread().getName() + "] released lock");
            });
            thread.start();
        }

        Runtime.getRuntime().addShutdownHook(new Thread(() -> {
            jedisPool.close();
            System.out.println("cause: " + (System.currentTimeMillis() - start) + "ms");
        }));
    }
}

Examples

You can find some examples in the examples module. If you want to simulate multiple-process, multiple-thread competition, you should run multiprocess/Step0, and then run multiprocess/Step1 within a 5-second window. You will see the result like this:

# process1:
# process [99991] thread [locking_thread_0] is getting lock
# process [99991] thread [locking_thread_8] is getting lock
# process [99991] thread [locking_thread_7] is getting lock
# process [99991] thread [locking_thread_6] is getting lock
# process [99991] thread [locking_thread_2] is getting lock
# process [99991] thread [locking_thread_5] is getting lock
# process [99991] thread [locking_thread_4] is getting lock
# process [99991] thread [locking_thread_3] is getting lock
# process [99991] thread [locking_thread_9] is getting lock
# process [99991] thread [locking_thread_1] is getting lock
# process [99991] thread [locking_thread_8] got lock
# process [99991] thread [locking_thread_8] released lock
# process [99991] thread [locking_thread_7] got lock
# process [99991] thread [locking_thread_7] released lock
# process [99991] thread [locking_thread_3] got lock
# process [99991] thread [locking_thread_3] released lock
# process [99991] thread [locking_thread_0] got lock
# process [99991] thread [locking_thread_0] released lock
# process [99991] thread [locking_thread_9] got lock
# process [99991] thread [locking_thread_9] released lock
# process [99991] thread [locking_thread_2] got lock
# process [99991] thread [locking_thread_2] released lock
# ...


# process2:
# process [96469] thread [locking_thread_498] is getting lock
# process [96469] thread [locking_thread_499] is getting lock
# process [96469] thread [locking_thread_152] got lock
# process [96469] thread [locking_thread_152] released lock
# process [96469] thread [locking_thread_139] got lock
# process [96469] thread [locking_thread_139] released lock
# process [96469] thread [locking_thread_417] got lock
# process [96469] thread [locking_thread_417] released lock
# process [96469] thread [locking_thread_213] got lock
# process [96469] thread [locking_thread_213] released lock
# process [96469] thread [locking_thread_458] got lock
# process [96469] thread [locking_thread_458] released lock
# process [96469] thread [locking_thread_124] got lock
# process [96469] thread [locking_thread_124] released lock
# process [96469] thread [locking_thread_204] got lock
# process [96469] thread [locking_thread_204] released lock
# ...