Question

The following are programming examples in which multithreading provides better performance than a single-threaded solution:

a. A Web server that services each request in a separate thread.

b. A matrix multiplication program where different parts of the matrix may be worked on in parallel.

c. An interactive GUI program such as a debugger where a thread is used to monitor user input, another thread represents the running application, and a third thread monitors performance.

On the other hand, the following are programming examples in which multithreading does NOT provide better performance than a single-threaded solution.

1. An individual tax return program that must does its calculation in a particular order.

b. Another example is a “shell” program such as the C-shell or Korn shell. Such a program must closely monitor its own working space such as open files, environment variables, and current working directory.

Provide one programming example in which multithreading provides better performance than a single-threaded solution. Also, provide one programming example in which multithreading does NOT provide better performance than a single-threaded solution. Your answers must be specific (e.g., a tax return program and a matrix multiplication program) and different from the ones that have already been mentioned above. Clearly explain to justify your answers.

Answer 1

Multithreading is benificial in the situations to achieve parallelism , where even if one thread task gets halted, the other thread operations work smoothly.

Single threaded solution is generally desirable in sequential tasks where, output of one function is the input to the next one. In that case, creating multiple threads will generate more overhead.

One example where Multithreading is better :-

• A music player that contains multiple tasks such as playing current song, displaying the play list, adding/deleting songs etc.
• All these different tasks can be managed with the help of multiple threads so that all individual tasks can be carried out independently and in parallel.
• In this case, single thread is not efficient to manage all the tasks.
• Even if there is some problem in one thread function, the other threads work smoothly.

One example where Single -Threaded Solution is better :-

• A program to find the average of given numbers.
• In this case, a single thread solution is better as it is a sequential problem where we first need to find the sum of numbers then divide the sum by count of given numbers.
• Employing multiple threads in this situation will be costly and time taking too.