Java Multithreading , Concurrency & Parallel Programming

Explore the basics of multithreading and multitasking, why they matter in programming, and the threats and possibilities enabled by multithreading.

Explore how multitasking works in computers by comparing process-based multitasking with thread-based multitasking, using examples like spreadsheet, music player, and browser to illustrate independent tasks within and across programs.

Learn how to create multiple threads in the same program, each with an independent execution flow, to boost responsiveness and performance on multicore processors.

Explore creating threads in Java, and examine the lifecycle of a thread, including how CPS could deal with threads and their journey from start to end.

Learn how to create threads in Java by extending Thread or implementing Runnable, use Java 8 lambdas, compare sequential and multi-threaded execution, and choose an approach with interfaces for flexibility.

Explore how the thread scheduler governs execution order, shaped by operating system algorithms, and trace the thread life cycle from new to ready, running, blocked, waiting, sleeping, and dead state.

Explore core multithreading concepts, including thread name and thread priorities, and learn how to use the sleep method and interrupting threads through sample program implementations.

Explore thread creation through diverse constructors, name management with getName and setName, and the priority system from 1 to 10 with default 5.

Explores the yield method in Java threads, showing how yielding lets other same-priority threads run, impacts scheduling, and contrasts with join and other coordination topics in multithreading.

Explore how the join method makes a thread wait for another to finish, handle interrupted exceptions, and understand deadlock risks with practical Eclipse examples.

Learn how the sleep method pauses a thread for a specified duration, like 10000 milliseconds. See how an InterruptedException can move a thread from sleeping back to ready.

Explore when and how to interrupt a thread in Java, using Thread.interrupt, isInterrupted, and Thread.interrupted, and understand how interruptions affect sleeping or waiting states and trigger InterruptedException.

Conclude the section by summarizing how to use trade name to priorities, reinforcing the discussion, and pointing to the next section.

Explore the core concepts of multi threading, including the JVM memory areas for variables, and distinguish atomic and non-atomic variables while examining the challenges of multi threading.

Explore how heap and stack memory manage objects and references across threads. See how shared heap data can cause data inconsistency in multi-threading.

Explore race conditions and data races in Java multithreading, contrasting atomic and non-atomic operations and how synchronization prevents inconsistent output on shared resources.

Tackle concurrency challenges and correctness in Java by examining volatile and atomic classes, with increment and get methods, then introduce synchronization and explicit locks in the concurrent package.

Explore memory areas, atomic and non atomic variables, and techniques to overcome these challenges in Java multithreading.

Explore synchronization and locking techniques in Java, and examine immutability and safety to build robust multithreaded applications.

Identify critical sections and protect them with synchronization locks to ensure data consistency in multithreading. Use Java's synchronized keyword on methods and blocks to achieve mutual exclusion for shared resources.

Explore implicit locking with synchronized methods in Java multithreading, covering object-level and class-level locks, how synchronized access protects a shared counter, and the trade-offs with non synchronized methods.

Learn how to replace synchronized methods with synchronized blocks to protect only the critical section, achieving object- and class-level locking for better performance in Java multithreading.

explains inter-thread communication with wait, notify, and notifyAll on a shared object, using a producer–consumer queue and synchronized blocks.

Explains explicit lock interface as a flexible alternative to synchronized blocks, detailing reentrant lock and read lock and write lock implementations, and methods like lock, tryLock, lockInterruptibly, unlock, and newCondition.

Demonstrates using explicit locking with ReentrantLock to guard critical sections, replacing synchronized blocks; illustrates increment and decrement with lock and unlock, tryLock, fairness, and class-level locks.

Understand how immutable classes in Java ensure thread safety by preventing modification after construction, using final fields and no setters, while strings illustrate new object creation on attempted changes.

Apply synchronization and locking techniques in Java to prevent undesirable output in multithreaded programs, and embrace immutability for thread safety. Explore deadlock, livelock, and starvation in concurrency.

Explore deadlocks, starvation, and livelock, and learn prevention techniques. Understand how synchronization and locking affect thread safety and race conditions to avoid new deadlocks and starvation.

Explore liveness problems in Java multithreading, including deadlock, starvation, and livelock, with code examples and fixes for acquiring locks in a consistent order.

Learn how daemon threads run in background, differ from user threads, and how the JVM terminates them after user threads finish; set the thread as daemon.

Explore advanced multithreading concepts, address lifecycle and concurrency problems, and learn to execute tasks via thread pools using callable and future.

Explore thread groups as collections of threads performing similar tasks, enabling suspend, resume, or interrupt for a whole group, such as consumer, possessor, and responder, within the system group.

Explore how to create custom thread groups in Java with two constructors, understand parent-child relationships, and learn key methods like get name and get max priority.

Explore how the executor framework uses a thread pool to execute tasks efficiently. Create a fixed pool of 20 threads, submit 100 tasks, and shut down the pool.

Understand the callable interface in Java multithreading, a functional interface with public Object call() throws Exception, allowing any return type and using a list of callables to create threads.

Explore how callable represents asynchronous tasks and how futures deliver non blocking results; submit returns a future and get blocks until completion with a factorial example.

Explore thread local in Java to give each thread its own variable, preventing shared state issues; see how per-thread copies of simple date format enable thread-safe formatting without global synchronization.

Recap thread pools, callable, and future concepts and demonstrate how to apply them in real-life concurrency scenarios.

Explore fail-fast behavior and the concurrent modification exception in Java collections, then see how concurrent collections, copy-on-write lists and sets, and the concurrent hash map address these issues.

Explore the need for concurrent collections in Java, where multiple threads access shared data and synchronized collections like Vector and Hashtable, using Collections.synchronized to prevent data inconsistency.

Explore the concurrent modification exception in Java collections by watching a thread iterate a list while another adds elements, then review the demo and plan how to overcome it.

Discover how concurrent collections solve performance and modification problems by locking only segments instead of the whole collection, improving efficiency and reducing concurrent modification exceptions.

Explore the Java concurrent hash map, its place in the map hierarchy, and key methods like put, remove, and replace, with practical examples.

Explore how concurrent hash map improves performance by locking only specific segments instead of the whole map, with 16 buckets by default, configurable concurrency level, and nulls not allowed.

Demonstrate how a concurrent hash map behaves in a multi-threading environment with a program demo. Contrast it with a regular hash map and show how failsafe iteration avoids concurrent modification.

Compare copy on write arraylist, a thread-safe variant of arraylist that clones on each write, making iterators failsafe. Note the performance overhead and that remove operations via iterator are unsupported.

Explore the copy-on-write set, a concurrent set backed by a list where writes run on a clone while reads use the main copy, preserving unique elements and JVM synchronization.

Learn how Java countdown latch synchronizes threads by decrementing a shared counter to zero, unblocking the main thread, with notes on reuse limits and cyclic barrier as an alternative.

Learn how a cyclic barrier coordinates multiple threads in Java, blocking until all tasks reach the barrier, then allowing the master to process results and repeat cycles.

Explore blocking queue concepts in Java, showing how put and take block producers and consumers to manage the queue with first-in-first-out ordering.

Explore the exchanger in Java concurrent programming, a two-way synchronization point where threads swap items via the exchange method, blocking until a partner arrives, enabling direct handoffs without buffering.

Explore simple and binary semaphores in Java to control access to shared resources using acquire and release, enabling mutual exclusion and thread coordination with permit counts.

explain how to tackle collection fail-fast behavior and concurrent modification exceptions, and introduce a concurrent hash map with copy-on-write, plus utilities like blocking queues, cyclic barriers, and semaphores.