Multithreading Interview Questions in Java for Experienced
- What is the synchronization process? …
- What is synchronized method and synchronized block? …
- What is thread starvation? …
- What is Livelock? …
- What is BlockingQueue? …
- Can you start a thread twice? …
- Explain context switching. …
- What is CyclicBarrier and CountDownLatch?
Indeed, What is multithreading with example?
Multithreading enables us to run multiple threads concurrently. For example in a web browser, we can have one thread which handles the user interface, and in parallel we can have another thread which fetches the data to be displayed. So multithreading improves the responsiveness of a system.
Then, What is deadlock in multithreading? Deadlock describes a situation where two or more threads are blocked forever, waiting for each other. Deadlock occurs when multiple threads need the same locks but obtain them in a different order.
What are some best examples of multithreaded applications? Some multithreaded applications would be:
- Web Browsers – A web browser can download any number of files and web pages (multiple tabs) at the same time and still lets you continue browsing. …
- Web Servers – A threaded web server handles each request with a ne.
In the same way Which map class should be used in multithreading? In a multi-threading environment, where multiple threads are expected to access a common Map, the ConcurrentHashMap is clearly preferable.
Can you start a thread twice?
No. After starting a thread, it can never be started again. If you does so, an IllegalThreadStateException is thrown. In such case, thread will run once but for second time, it will throw exception.
Which is best suited to a multithreaded environment?
Answer is “ConcurrentHashMap”
What interface handles sequences?
Discussion Forum
Que. | Which of these interface handle sequences? |
---|---|
b. | List |
c. | Comparator |
d. | Collection |
Answer:List |
What happens when thread’s sleep () method is called?
Sleep() – This method causes the currently executing thread to sleep (temporarily cease execution) for the specified number of milliseconds. The thread does not lose ownership of any monitors. It sends the current thread into the “Not Runnable” state for a specified amount of time.
What is difference between wait () and sleep () method?
It tells the calling thread (a.k.a Current Thread) to wait until another thread invoke’s the notify() or notifyAll() method for this object, The thread waits until it reobtains the ownership of the monitor and Resume’s Execution.
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Difference between wait and sleep in Java.
Wait() | Sleep() |
---|---|
Wait() is not a static method. | Sleep() is a static method. |
• 16 juin 2021
In what scenarios can we interrupt a thread?
Java Thread interrupt() method
The interrupt() method of thread class is used to interrupt the thread. If any thread is in sleeping or waiting state (i.e. sleep() or wait() is invoked) then using the interrupt() method, we can interrupt the thread execution by throwing InterruptedException.
What happens if we call run directly instead start () method?
If run() method is called directly instead of start() method in Java code, run() method will be treated as a normal overridden method of the thread class (or runnable interface). This run method will be executed with in the context of the current thread not in a new thread.
Which collection will use in multithreaded environment?
You could use a concurrent hash set created from the ConcurrentHashMap : Set<K> set = Collections. newSetFromMap(new ConcurrentHashMap<K, Object>()); This collection is thread-safe and has the features of the ConcurrentHashMap – it’s faster than Collections.
What is the basis of encapsulation?
What is ‘Basis of Encapsulation’? Explanation: Encapsulation is the mechanism that binds together code and data it manipulates, and keeps both safe from outside interface and misuse. Class, which contains data members and methods is used to implement Encapsulation.
Does TreeSet maintain insertion order?
In order to add an element to the TreeSet, we can use the add() method. However, the insertion order is not retained in the TreeSet. Internally, for every element, the values are compared and sorted in ascending order.
What is collections synchronizedList?
The synchronizedList() method of java. util. Collections class is used to return a synchronized (thread-safe) list backed by the specified list. In order to guarantee serial access, it is critical that all access to the backing list is accomplished through the returned list.
What is the difference between yield and join?
Yield means currently executing thread gives chance to the threads that have equal priority in the Thread-pool .
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Difference between Yield and Join Method in Java with Example.
Yield | Join | |
---|---|---|
State Change | running to runnable | If the method join() called on the Thread instance, a thread will not start running until another thread finish executing. |
Keywords Used | static,native | final |
What is notify () in Java?
The notify() method is defined in the Object class, which is Java’s top-level class. It’s used to wake up only one thread that’s waiting for an object, and that thread then begins execution. The thread class notify() method is used to wake up a single thread.
What is wait () in Java?
Simply put, wait() is an instance method that’s used for thread synchronization. It can be called on any object, as it’s defined right on java. lang. Object, but it can only be called from a synchronized block. It releases the lock on the object so that another thread can jump in and acquire a lock.
Why sleep () is static method?
The code would only execute when someXThread was executing, in which case telling someYThread to yield would be pointless. So since the only thread worth calling yield on is the current thread, they make the method static so you won’t waste time trying to call yield on some other thread.
What is sleep method in Java?
The sleep() method is a static method of Thread class and it makes the thread sleep/stop working for a specific amount of time. The sleep() method throws an InterruptedException if a thread is interrupted by other threads, that means Thread.
How do you stop a runnable?
You can call cancel() on the returned Future to stop your Runnable task. cancel attempts to cancel the execution but doesn’t guarantee it.
Why sleep method throws InterruptedException?
sleep() method throws InterruptedException if a thread in sleep is interrupted by other threads. InterruptedException is a checked type of exception. That means, “Thread. sleep()” statement must be enclosed within try-catch blocks or it must be specified with throws clause.
What is valid about ThreadLocal?
Java ThreadLocal class provides thread-local variables. It enables you to create variables that can only be read and write by the same thread. If two threads are executing the same code and that code has a reference to a ThreadLocal variable then the two threads can’t see the local variable of each other.
What is thread synchronization?
Synchronization is the cooperative act of two or more threads that ensures that each thread reaches a known point of operation in relationship to other threads before continuing. Attempting to share resources without correctly using synchronization is the most common cause of damage to application data.
Why thread is called Start method?
The purpose of start() is to create a separate call stack for the thread. A separate call stack is created by it, and then run() is called by JVM. Let us see what happens if we don’t call start() and rather call run() directly.
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