[Java] Multithreading in java

Multithreading in java

1. Advantage of Java Multithreading

- It doesn't block the user because threads are independent and you can perform multiple operations at same time

- You can perform many operations together so it saves time

- Threads are independent so it doesn't affect other threads if exception occur in a single thread

2. MultiTasking

- Multitasking is a process of executing multiple tasks simultaneously

- We use it to utilize the CPU

- Multitasking can be achieved by two ways

1) Process-based Multitasking(Multiprocessing)

2) Thread-based Multitasking(Multithreading)

1) Process-based Multitasking(Multiprocessing)

- Each process have its own address in memory i.e. each process allocates separate memory area

- Process is heavyweight

- Cost of communication between the process is high

- Switching from one process to another require some time for saving and loading registers, memory maps...

2) Thread-based Multitasking(Multithreading)

- Threads share the same address space

- Thread is lightweight

- Cost of communication between the thread is low

3. Thread

- A thread is a lightweight sub process

- smallest unit of processing

- Threads are independent, if there occurs exception in one thread, it doesn't affect other threads

- It shares a common memory area

- Thread is executed inside the process

- There can be multiple processes inside the OS and One process can have multiple threads

- At a time one thread is executed only