Visualization of Mutual Exclusion Algorithms by Means of a Pictogram Programming Environment

Courses in computer science and information and communication technologies can include a wide range of topics from the basics of programming and elementary knowledge about the structure of computers to the theory of formal grammars, artificial intelligence languages, operating systems, 3D graphics, etc. The main difficulty in this case is the mathematical component of the courses, which requires appropriate training of students. However, in programming there is content that is quite difficult for students to understand, even with deep academic knowledge. This area is parallel programming, when, on the one hand, it is required to study and write educational highly efficient algorithms for solving problems for performing simultaneous calculations on different computers or processors, on the other hand, it is no less difficult to understand - ensuring the parallel operation of various parts of a program with a shared access to shared data. The development of the latter is complicated by the lack of adequate visualization of the parallel operation of processes on a computer. It remains for teachers to illustrate the topic with pictures from the real world, giving various arguments to prove the importance of solving the problem of sharing common resources, citing, as one of the options, the simultaneous free moving of four cars at a crossroad. On the other hand, current trends require lowering the age of the beginning of acquaintance with the elements of programming and algorithmization. Preschoolers, children of the fourth year of life, successfully master the basic concepts of sequential programming using program-controlled robots and their virtual counterparts in the digital educational environment PiktoMir. The same DEE PiktoMir is used for programming propaedeutics in teaching for all ages, including university students. PiktoMir is not only easy to learn, but allows the use of several robot performers in tasks at the same time, each of which acts according to its own program. The visibility of the program execution process in the system led the authors to the idea of using the DEE PiktoMir to demonstrate the operation of classical mutual exclusion algorithms in courses on parallel programming. The experience of the authors showed the high efficiency of this approach, which allowed students to understand the problem in a short time and successfully solve all the problems of the course. This approach was tested in the courses Operating Systems (IIS SUM) and Algorithms and Data Structures (Institute of Childhood, Moscow State Pedagogical University).

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