The block diagram is a visual tool that helps to turn a complex algorithm into an understandable and structured sequence of actions. From programming to business process management, they serve as a universal language for visualization, analysis and optimization of the most complex systems.
Imagine a map where instead of roads is logic, and instead of cities – actions. This is a block diagram-an indispensable tool for navigation in the most confusing processes.
Example 1: Simplified game launching scheme
To understand the principle of work, let’s present a simple game launch scheme.
This scheme shows the perfect script when everything happens without failures. But in real life, everything is much more complicated.
Example 2: Expanded scheme for starting the game with data loading
Modern games often require Internet connection to download user data, saving or settings. Let’s add these steps to our scheme.
This scheme is already more realistic, but what will happen if something goes wrong?
How was it: a game that “broke” with the loss of the Internet
At the start of the project, developers could not take into account all possible scenarios. For example, they focused on the main logic of the game and did not think what would happen if the player has an Internet connection.
In such a situation, the block diagram of their code would look like this:
In this case, instead of issuing an error or closing correctly, the game froze at the stage of waiting for data that she did not receive due to the lack of a connection. This led to the “black screen” and freezing the application.
How it became: Correction on user complaints
After numerous users’ complaints about hovering, the developer team realized that we needed to correct the error. They made changes to the code by adding an error processing unit that allows the application to respond correctly to the lack of connection.
This is what the corrected block diagram looks like, where both scenarios are taken into account:
Thanks to this approach, the game now correctly informs the user about the problem, and in some cases it can even go to offline mode, allowing you to continue the game. This is a good example of why block diagrams are so important : they make the developer think not only about the ideal way of execution, but also about all possible failures, making the final product much more stable and reliable.
Uncertain behavior
Hanging and errors are just one examples of unpredictable behavior of the program. In programming, there is a concept of uncertain behavior (undefined behavior) – this is a situation where the standard of the language does not describe how the program should behave in a certain case.
This can lead to anything: from random “garbage” in the withdrawal to the failure of the program or even serious security vulnerability. Indefinite behavior often occurs when working with memory, for example, with lines in the language of C.
An example from the language C:
Imagine that the developer copied the line into the buffer, but forgot to add to the end the zero symbol (`\ 0`) , which marks the end of the line.
This is what the code looks like:
#include
int main() {
char buffer[5];
char* my_string = "hello";
memcpy(buffer, my_string, 5);
printf("%s\n", buffer);
return 0;
}
Expected result: “Hello”
The real result is unpredictable.
Why is this happening? The `Printf` function with the specifier`%S` expects that the line ends with a zero symbol. If he is not, she will continue to read the memory outside the highlighted buffer.
Here is the block diagram of this process with two possible outcomes:
This is a clear example of why the block diagrams are so important: they make the developer think not only about the ideal way of execution, but also about all possible failures, including such low-level problems, making the final product much more stable and reliable.
