Multitasking
A process of executing multiple tasks simultaneously is known as Multitasking. It is of two types.
1. Process-Based Multitasking
2. Thread-Based Multitasking
Process-Based Multitasking
It is executing multiple processes at the same time, where each process runs independently with it's own allocated resources.
Characteristics
- The process is a heavyweight.
- The high communication costs involved in the process.
- Each process allocates a separate memory area i.e. each process has an address in memory.
Example: Running a video player while using a web browser.
Thread-Based Multitasking
It is executing multiple threads within a single process
Characteristics
- Thread is a small unit of processing that operates as a lightweight sub-process..
- The cost of communication between the Thread is low.
- It uses a shared memory area, they don't allocate separate memory areas so Threads saves memory.
- Thread is independent. If any exception occurs in one Thread it doesn't affect another thread.
Example: In a web browser, one thread handles UI rendering, while another thread manages network requests.
Comparison Between Process-Based Vs. Thread-Based Multitasking
| Feature | Process-Based Multitasking | Thread-Based Multitasking |
|---|---|---|
| Definition | Running multiple processes at a time | Running multiple threads within a process |
| Memory Allocation | Every process has own address space | Threads share memory |
| Resource | high (Each process is independent) | Low (Shared memory) |
| Communication Cost | High | Low |
| Speed | Slow | Fast |
| Example | Multiple applications (Word + Browser) | Multiple threads in a single app (UI + Network in a browser) |