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What is Asynchronous?

Programming has come a long way over the years, and every day we see the introduction of new languages ​​or technologies. Every new tool that is seeking to solve a problem and tries to improve the current situation. In fact, the languages, frameworks, and all the programming tools we use today have been the result of the efforts of many people over the years. Today we go to a concept called Asynchronous and review the challenges that this model is trying to solve. After reading this article, you will understand what Asynchronous method is, how it differs from Synchronous and what its uses are. be with us.

What is Synchronous Programming?

To understand the concept of asynchronous programming, it is better to first know synchronous programming. In this method, programmer codes are consecutive and linear. That is, if our program has 400 lines of code, the commands and functions are from line 1 and in turn until we reach line 400 and the program runs. In this method of programming, the commands must be in order, and until function “a” is not, function “b” can not performing.

Saying a few things will help you become more familiar with this type of programming. Searching in several valid dictionaries leads to the following results: Synchronous: Simultaneous, simultaneous, occurring simultaneously. You see, all of these words refer to a concept which it means “time.” But in this method, everything is not in time and we do not necessarily have to summarize everything in time. Rather, Synchronous means that the code is consecutive, which can depend on things other than time. So be careful that the translation of this word does not mislead you.

Another point is whether this method is good or bad. We should not think that with the coming to power of Asynchronous, the Synchronous is dead and we should stop using it. In general, a technology cannot be good or bad. We need to see where this technology is and what capabilities it has. In the Synchronous method, the situation is the same and if used in the right place, it will lead to amazing results.

A few examples in the Synchronous programming method

There are many examples of synchronous programming. In fact, many programmers are consciously or unconsciously using this method. But for more familiarity, it is better to examine several scenarios together. In a simple example, we write a piece of code in Python that takes an input from the user and prints it on the screen:

In the example above, everything is clear, linear rule. The user enters an input and the program prints that input. Another example could be a delay in downloading a file. Suppose our program is going to download information and then make changes to that data.

Did you notice the problem? In fact, the program can not make its own changes until the files are finished downloading. If there was a way for the program to process part of the file by downloading it, how much positive effect would it have on the program’s performance? Or when the program is downloading files, we can run other functions of the program. It is precisely for these reasons and benefits that we turn to Asynchronous programming.

What is Asynchronous Programming?

Asynchronous programming is a model and concept in programming. In this model, unlike the Synchronous method, our codes are not executed consecutively, and the so-called sequence of codes is nonlinear. It is no longer mandatory for our 400-line program to run from line 1 to line 400, respectively, and this routine can be changed. Or we can better implement the example we gave about downloading and processing files with the help of Asynchronous. Dedicate the CPU to other sections while the files are downloading. So in Asynchronous there is no sequential execution of commands. But what is the reason for disrupting the execution of code in the program?

The CPU is the vital organ and mastermind of the computer. It is easy to ignore components such as graphics cards, external sound cards, coolers or DVD burners, but without the CPU our computer will not even turn on. Now, what do you think is the reason for dismissing this important member even for a moment? With the help of Asynchronous programming method, we can make the most of hardware resources.

Asynchronous can solve many of our problems. This method is completely opposite to Synchronous in terms of execution order, and we can have multiple execution flows or Control Flow in one program. Asynchronous is a bit like solving puzzles. Just as we do not use linear order when picking puzzles and put the pieces of the puzzle together according to different conditions, in the Asynchronous method the processes are not in a specific order.

Will Asynchronous programming speed up our program?

There is no guarantee that using multiple Control Flows and taking the program out of linear and sequential mode will speed up your program execution. In fact, this executable model sometimes has no effect on the speed of the program and may even reduce the speed of the program in some cases. If you decide to use Asynchronous to speed up your execution, you should reconsider your decision. If you use this technology in the right place, it can lead to great results. In fact, every time you write code, you have to ask yourself if using Asynchronous will work. For example, you can ask if it is better in this part of the program when I am reading a file, should I run a process behind the scenes or not. If the answer is yes, using Asynchronous can be a great help.

Is the Asynchronous model dependent on a specific programming language or framework?

Asynchronous alone is a concept. It is better not to get into programming when we are studying it theoretically. Once we understand this model well, we can use it when coding. Programming languages ​​offer a variety of ways to implement this model, which may vary slightly depending on the language we use. For example, in C # and after the .NET Framework technology version 4.5 onwards, the two keywords Async and Await were introduced and took on the task of asymmetric data processing. Remember that Asynchronous operations are not limited to the .NET Framework and C # programming language and can be used in many different areas.


In this article, we explored what the concept of asynchronous is and what its uses are. First we talked about Synchronous and said that in this way our program runs line by line. Instead, we came up with the Asynchronous model, which disrupted the order so that our program would not be delayed for a long time and manage other processes. We also mentioned its application in .NET Framework technology. Asymmetric and asynchronous processes may seem appealing at first glance, but you have to decide whether to use them based on the circumstances of your program.