There are many concepts and algorithms in the study of real-time systems. This project attempts to implement them to see their real behaviors in a real machine making it easier to understand the concepts and algorithms while allowing some real experimentations out of curiosity to concretely see some problems like chained blocking in priority inheritance and scheduling bug in a particular operating system.

The codebase is divided logically into two parts:

1. Infrastructure components.
2. Experimentation components.

The first part contains software components that are used in developing experimentation components. Each component should be in the form of a single source file accompanied with a program to run test cases that test the corresponding source file for semantical correctness and the absent of memory leak and memory violations and other things. As an example, the software component utility_time is developed using C programming language and as such consists of utility_time.h, utility_time.c (can be absent if all functions are inlined) and utility_time_test.c. The test program is then registered in the Makefile to be run with `make check'. The infrastructure software components are usually developed by refactoring common functions from the experimentation components. The infrastructure software components and their Makefile are located in the base directory.

The second part contains software components that are used to understand some concepts, algorithms or problems related to the study of real-time systems. Each experimentation software component should be in the form of a single directory containing one README file describing the concept(s) or algorithm(s) or problem(s) that the component wishes to demonstrate, one or more source or data files, and one Makefile. To create a new experimentation software component, execute `make new_experiment EXP_NAME=DESIRED_EXPERIMENT_NAME' replacing DESIRED_EXPERIMENT_NAME with the actual name of the new experimentation component. Then, go to directory "DESIRED_EXPERIMENT_NAME" and edit README describing the purpose of the experiment. Afterwards, main.c and Makefile found in the directory can be adjusted accordingly. The following files can be added to the list of executables in Makefile to obtain the executables in the experimentation directory: cpu_hog_cbs

Usually an experimentation software component will produce some binary log files that can be read using infrastructure software component named read_task_stats_file.

The infrastructure component read_task_stats_file produces a GNU Octave (Matlab-compatible) command to plot the cummulative distribution of the task response times as the last line in its output. The command will not be output if the task log file carries no record of job execution statistics.

The infrastructure component sched_switch can be used to generate the execution time line of a set of real-time tasks in the form of .vcd file to be read and displayed by gtkwave from the output of ftrace sched_switch plugin. Source: https://www.osadl.org/Single-View.111+M530bed48137.0.html?&tx_ttnews[month]=06&tx_ttnews[year]=2009

Each file defining main() function must also define two global variables and initialize them appropriately as follows: const char prog_name[] = "PROGRAM_NAME"; FILE log_stream; / Initialize this at the very beginning of main()

• so that the logging facility can work properly */

The codebase is Free Software licensed under GNU GPL version 3 and is developed to support the thesis work of Tadeus Prastowo in the area of real-time systems.