What is use of volatile in Java?

Volatile keyword is used to modify the value of a variable by different threads. It is also used to make classes thread safe. It means that multiple threads can use a method and instance of the classes at the same time without any problem.

Why do we need volatile?

Conclusion. The volatile field is needed to make sure that multiple threads always see the newest value, even when the cache system or compiler optimizations are at work. Reading from a volatile variable always returns the latest written value from this variable.

What is the use of volatile?

The volatile keyword is intended to prevent the compiler from applying any optimizations on objects that can change in ways that cannot be determined by the compiler. Objects declared as volatile are omitted from optimization because their values can be changed by code outside the scope of current code at any time.

How does volatile work in Java?

Since volatile keyword in Java only synchronizes the value of one variable between Thread memory and “ main ” memory while synchronized synchronizes the value of all variable between thread memory and “ main ” memory and locks and releases a monitor to boot.

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Is volatile thread safe in Java?

Using volatile is yet another way (like synchronized, atomic wrapper) of making class thread safe. Note that write of normal variables without any synchronization actions, might not be visible to any reading thread (this behavior is called sequential consistency). …

Can we use const and volatile together?

Yes. A variable can be declared as both volatile and constant in C. Const modifier does not allow changing the value of the variable by internal program. … So, a variable can be both volatile and constant in C.

What is race condition in Java?

Race conditions occur when two threads operate on the same object without proper synchronization and their operation interleaves on each other. … This is also a popular multi-threading interview question during core java interviews.

Why volatile is used in Singleton?

The volatile prevents memory writes from being re-ordered, making it impossible for other threads to read uninitialized fields of your singleton through the singleton’s pointer.

What is a volatile person?

A person who is volatile loses his or her temper suddenly and violently. A volatile political situation could erupt into civil war. When the stock market is volatile, it fluctuates greatly. And in scientific language, a volatile oil evaporates quickly.

What is atomic keyword in Java?

Atomicity. Atomic operations are those operations that ALWAYS execute together. Either all of them execute together, or none of them executes. If an operation is atomic, then it cannot be partially complete, either it will be complete, or not start at all, but will not be incomplete.

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What is difference between static and volatile in Java?

volatile variable value access will be direct from main memory. It should be used only in multi-threading environment. static variable will be loaded one time. If its used in single thread environment, even if the copy of the variable will be updated and there will be no harm accessing it as there is only one thread.

Is package a keyword in Java?

Java package is a group of similar classes and interfaces. Packages are declared with the package keyword. The private keyword is used in the declaration of a method, field, or inner class; private members can only be accessed by other members of their own class.

Is null a keyword in Java?

null is Case sensitive: null is literal in Java and because keywords are case-sensitive in java, we can’t write NULL or 0 as in C language. 2. Reference Variable value: Any reference variable in Java has default value null.

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