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A private mutex (or private lock object) is often used to gain fine-grained control over synchronization without exposing the locking mechanism to the outside world.

Here are the key reasons you might want to use a private mutex instead of synchronized(this) or synchronized(SomeClass.class):

Yes, new instances of a class can be created while a static synchronized method is executing.

Let’s break it down:

🔒 static synchronized method

• It locks on the Class object, not on an instance.
• So, if thread A is executing a static synchronized method, it holds the class-level lock.

💡 Creating new instances

• Creating an object via new MyClass() does not require any lock.
• It’s simply calling a constructor, which is not synchronized by default.
• Therefore, other threads can create new instances of the class, even while the static synchronized method is running.

Let’s walk through the 6 thread states in Java, according to the java.lang.Thread.State enum.

🧵 Java Thread States

Let’s compare wait()/notify() (used with synchronized) and Condition (used with ReentrantLock) — both are used for thread coordination, but Condition gives you more flexibility.

We’ll walk through:

1. A wait()/notify() example
2. A Condition example doing the same thing

Scenario: We have a producer and consumer. The producer sets a flag when data is ready; the consumer waits until that happens.

🔎 Key Criteria to Decide:

1. Do you need mutual exclusion?
2. Do you need only visibility or atomicity?
3. Do you need fine-grained locking or advanced features like try-lock, fairness, etc.?
4. Are threads coordinating around a condition (like a signal or phase)?

Let’s look at each scenario 👇

🧠 1. Intrinsic (Built-in) Synchronization

This is the most commonly used type of synchronization in Java, based on monitors.

A. Synchronized Method

public synchronized void increment() {
    // Only one thread at a time can execute this method
}

Locks on the current object (this)

For static methods, it locks on the class object (ClassName.class)

🧠 What is Synchronization?

Synchronization is the process of controlling access to shared resources by multiple threads to prevent race conditions, data inconsistency, and memory visibility issues.

💡 First: A Monitor in Java = A Mutex + Condition Variable

Java’s monitor is not just a lock — it’s a synchronization mechanism that includes:

• a mutex (for mutual exclusion)
• zero or more condition queues (for waiting/notification: wait(), notify())

🧠 First, What Is a Monitor?

A monitor is a mutex (mutual exclusion lock) + condition variable attached to every object in Java.

• Every Java object has one monitor.
• A monitor ensures that only one thread at a time can hold the monitor lock on the object.
• When a thread holds the monitor, other threads trying to lock it are blocked until it’s released.

Let’s unpack it carefully — the short answer is: ✅ they behave the same, but 🚀 give you flexibility in different contexts.