Mastering tldb Distributed Locks: Go & Java Guide to Lock, TryLock, and Unlock

Distributed locks are a crucial tool in distributed systems, and tldb provides a simple, reliable API that mimics object locks in programs.

tldb distributed lock usage:

lock – a blocking request for a lock.

trylock – attempts to acquire a lock; returns immediately with success or failure.

unlock – releases a previously acquired lock.

Lock (string,int) Method Usage

tldb offers an exclusive lock based on a string identifier. The call lock("abc",3) requires two parameters:

The first parameter is the lock object name; the server assigns a global lock for that name.

The second parameter is the maximum hold time in seconds; after this period the server forcibly releases the lock if it hasn't been unlocked.

UnLock (string) Method Usage

Unlock releases the distributed lock. After acquiring a lock, the server returns a key; the client must call UnLock(key) to release it, otherwise the server will release it after the timeout.

TryLock (string,int) Method Usage

TryLock works like lock but is non‑blocking; it returns immediately with a key if successful, or empty data if the lock is already held.

Go Example – Using lock

import "github.com/donnie4w/tlmq-go/cli"

sc := cli.NewMqClient("ws://127.0.0.1:5001", "mymq=123")
sc.Connect()
key, err := sc.Lock("testlock", 3)
if err != nil {
    // handle lock failure
}
defer sc.UnLock(key)
// business logic here

Go Example – Using tryLock with spin wait

sc := cli.NewMqClient("ws://127.0.0.1:5001", "mymq=123")
sc.Connect()
var key string
for {
    if v, ok := sc.TryLock("testlock", 3); ok {
        key = v
        break
    } else {
        <-time.After(100 * time.Millisecond)
    }
}
defer sc.UnLock(key)
// business logic here

Java Example – Maven Dependency

<dependency>
    <groupId>io.github.donnie4w</groupId>
    <artifactId>tlmq-j</artifactId>
    <version>0.0.2</version>
</dependency>

Java Example – Using lock

MqClient mc = new SimpleClient("ws://127.0.0.1:5001", "mymq=123");
mc.connect();
String key = null;
try {
    key = mc.lock("testlock", 3);
    // business logic
} finally {
    if (key != null) {
        mc.unLock(key);
    }
}

Java Example – Using tryLock

MqClient mc = new SimpleClient("ws://127.0.0.1:5001", "mymq=123");
mc.connect();
String key = null;
try {
    key = mc.tryLock("testlock", 3);
    // business logic
} finally {
    if (key != null) {
        mc.unLock(key);
    }
}

Test Data

Performance tests show multi‑threaded concurrency when multiple threads request the same lock using lock or tryLock with spin‑wait. The following images illustrate the test results.