Introduction

Multiprogramming and multitasking are fundamental concepts in concurrent computing, each contributing to efficient resource utilization and improved system performance. While both involve the execution of multiple tasks, they exhibit nuanced differences in their core objectives, mechanisms, and applications. A comprehensive understanding of the distinctions between multiprogramming and multitasking is crucial for designing sophisticated operating systems that cater to diverse computing needs.

Multiprogramming

Definition and Purpose: Multiprogramming is a computing paradigm that involves the simultaneous execution of multiple programs by a computer system. The primary objective is to maximize CPU utilization and minimize idle time by loading several programs into the memory.

Mechanism: In a multiprogramming environment, multiple programs are present in the memory simultaneously. The CPU scheduler selects a program from the ready queue, and when the executing program is interrupted or awaits an I/O operation, control shifts to another program. This overlapping of CPU and I/O operations ensures that the CPU is consistently engaged, leading to efficient resource utilization.

Use Cases: Multiprogramming is particularly effective in batch processing systems and time-sharing systems. It caters to scenarios where a mix of CPU-bound and I/O-bound processes can be executed concurrently, thereby maximizing the throughput of the system.

Multitasking

Definition and Purpose: Multitasking, on the other hand, involves the concurrent execution of multiple tasks or processes on a single processor. The primary goal is to provide users with the illusion of parallel execution, allowing them to interact with several applications simultaneously.

Mechanism: Multitasking achieves its objectives through time-sharing, where the CPU rapidly switches between different tasks. Each task is allocated a small time slice for execution before moving to the next task. This quick switching creates the appearance of simultaneous execution and is crucial for delivering a responsive user interface.

Use Cases: Multitasking is pervasive in modern operating systems found in personal computers, smartphones, and other devices. It caters to user expectations of running multiple applications concurrently, enhancing productivity and providing a seamless user experience.

Key Differences

1. Objective:
   • Multiprogramming: Aims to maximize CPU utilization by keeping the processor busy with the execution of multiple programs.
   • Multitasking: Focuses on maximizing user productivity by allowing the simultaneous execution of multiple user-level tasks.
2. Resource Allocation:
   • Multiprogramming: Involves loading multiple programs into memory, allowing the CPU to execute instructions from different programs in overlapping fashion.
   • Multitasking: Requires time-sharing and quick switching between tasks to provide the illusion of concurrent execution.
3. User Interaction:
   • Multiprogramming: Often operates in the background without direct user interaction, focusing on optimal system throughput.
   • Multitasking: Geared towards providing a responsive user interface, allowing users to interact with multiple applications concurrently.

Multi threading system’s working –

· Say there is a web server which processes client requests. Now if it executes as a single threaded process, then it will not be able to process multiple requests at a time. Firstly one client will make its request and finish its execution and only then, the server will be able to process another client request. This is really costly, time consuming and tiring task. To avoid this, multi threading can be made use of.

· Now, whenever a new client request comes in, the web server simply creates a new thread for processing this request and resumes its execution to hear more client requests. So the web server has the task of listening to new client requests and creating threads for each individual request. Each newly created thread processes one client request, thus reducing the burden on web server.

Multi threading in Rust

· To create a new thread, we call the thread::spawn function.

· The calls to thread::sleep force a thread to stop its execution for a short duration, allowing a different thread to run

· Join function is for execution of download without any interrupt.

the main calls function of get_two_sites_async, which calls other two functions names as download_asyn1 and download async_2 which download 2 files and store them in variable of future_one and future_two.Output store in function of get_two_sites_async and block_on in main display the results.

What is Multitasking Operating System?

When any program is running it is referred to as a task. In a Multitasking Operating System, two or more tasks are active simultaneously.

In this, we stop one task temporarily to work one another. It also means that the computer can work with more than one program at a time.

For instance, you can fetch information from one database on the screen analyzing data, while the computer is sorting data from another database, on the other hand performing calculations on a separate worksheet.

Another example is, In modern operating systems, we can play MP3 music, edit documents in Microsoft Word, surfing the Google Chrome all are simultaneous.

It is not same as “multiple loading” of applications, also referred to as “context switching” or “task switching,” In Context switching, several applications can be open, but only one application is working at a time. Multitasking based on the time-sharing along with context switching.

Multi tasking in Rust

In a typical threaded application, if you wanted to download two different webpage’s at the same time, you would spread the work across two different threads.

Comparison Chart

Conclusion

While multiprogramming and multitasking both involve the concurrent execution of tasks, they serve distinct purposes and operate under different mechanisms. Multiprogramming prioritizes optimal CPU utilization by loading multiple programs into memory, commonly used in scenarios like batch processing. On the other hand, multitasking focuses on providing users with a responsive interface by swiftly switching between tasks, prevalent in modern operating systems. Recognizing the differences between these concurrent computing concepts is essential for designing operating systems that cater to the diverse requirements of both system efficiency and user experience.