Multithreading

By Tiationg Kho |
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Multithreading

  • Multithreading is a Java feature that allows concurrent execution of two or more threads for maximum utilization of the CPU
  • Process vs Thread
    • A process is an executing program. It has its own memory space and resources
    • A thread is a single unit of execution within a process. Multiple threads within the same process share the same memory space
  • Main Thread
    • When a Java application starts, it creates a main thread, which is responsible for executing the main method
    • The main thread is the entry point of the program
  • Create a Thread
    • extends the Thread Class
    • implements the Runnable Interface
    • Use an ExecutorService for managing thread pool
  • Lifecycle of a Thread
    • New
      • When a thread is created
      • Use start() to become Runnable
    • Runnable
      • When the thread is ready to run but waiting for CPU time
      • Use run() to become Running
    • Running
      • When the thread is executing
      • Use sleep(), wait(), or join() to become Blocked
    • Blocked
      • When the thread is waiting for a resource
      • Use notify(), or notifyAll() to become Runnable
    • Terminated
      • When the thread has finished executing
  • synchronized
    • Ensures that only one thread can execute a synchronized method or block at a time
  • volatile
    • Used to indicate that a variable’s value may be changed by different threads