README.md

Project 2, class OS

Program: projeto.cpp

Version: 1.1

This project was idealized in OS classes. This is a program that simulate three robots with position got it by an camera (in this case, it's used random numbers) and then, the robots itself should move according with that.

The goal is to show how much one thread interferes with the anothers, as so, simulate an robot that it's used in competitions.

Overview

Summary:

1. Compiling
2. Commons features
3. Program Infos
4. PDF
5. Functions implemented
6. Comments

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Compiling

1. To compile only useful (working) file:

   CFLAGS="-std=c++11 $(pkg-config --cflags --libs sdl2)"
   
   # Compile
   g++ projeto.cpp -o p -lpthread $(echo $CFLAGS)
   # Those libs need to be in last position, otherwise, the compiler will not link
   # Execute
   ./p

   The flag -g is used in debug mode

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Commons

Positions on vectors

1. Camera

   The camera corresponds to pos 0, in vectors

2. GPS

   The gps corresponds to pos 1, in vectors

3. Odometro

   The odometro corresponds to pos 2, in vectors

4. Used only in color struct

   Corresponds to color of a 'blank screen'

   Macros:

5. ROBOTS_AMOUNT

    #define ROBOTS_AMOUNT 3

   Corresponds to how much robots do we have

6. SOURCES_AMOUNT

    #define SOURCES_AMOUNT ROBOTS_AMOUNT

   Corresponds to how much sources do we have

7. nullptr

    #define nullptr NULL

8. error_on_initialize()

        #define error_on_initialize() \
            { printf("Error on initialize. Code: %s\n", SDL_GetError()); }

   Used in sdl2 errors

Consts:

1. Boards (screen)

    const int BOARD_Y = 300;
    const int BOARD_X = 400;

2. Time in seconds

    const int TIME_MIN = 0; // in seconds
    const int TIME_MAX = 4;
    const int TIME_EQUIPAMENTS[ROBOTS_AMOUNT] = {TIME_MIN, TIME_MIN, TIME_MIN}; // Remember the order in positions...

3. Buffer size limit

    const int BUFFER_SIZE_MAX = 100;

4. Iterator needed to pass id to each thread

    int aux_iterator_amount[3] = {0, 1, 2};

   Note that the 3 it's because the set up value in macro ROBOTS_AMOUNT

5. Screen size

    const int SCREEN_WIDTH = BOARD_X + ROBOT_HEIGHT,
          SCREEN_HEIGHT = BOARD_Y + ROBOT_WIDTH;

   This is only used in sdl function

6. Robot sizes

    const int ROBOT_HEIGHT = 20, ROBOT_WIDTH = 20;

Structs:

1. Object

    struct object {
        int x, y, robot, source;
        object(int x, int y, int robot, int source) {
            this->x = x;
            this->y = y;
            this->robot = robot;
            this->source = source;
        }
    };

   Used in buffer.

2. Unnamed

    struct {
        bool mark_equipament[SOURCES_AMOUNT];
        int position[SOURCES_AMOUNT][2];
    } robots[ROBOTS_AMOUNT];

   Used to storage robots before draw them.

3. Unnamed

    struct {
    Uint8 r, g, b, a;
    } colors[ROBOTS_AMOUNT + 1] = {
        {37, 85, 179, 1}, {148, 71, 194, 1}, {49, 106, 79, 1}, {30, 30, 30, 1}};

   Store robots and board(last one) colors.

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Infos

Compiler Version:

• g++ 11 + (11, or newest)

Libs needed:

#include <SDL2/SDL.h>   // sdl2
#include <pthread.h>    // threads
#include <semaphore.h>  // semaphore
#include <unistd.h>     // sleep,
#include <cstdlib>      // rand
#include <ctime>        // seed,
#include <queue>        // buffer

The package SDL2-Version:2.0.9 can be found: in ubuntu repo as

sudo apt-get install libsdl2-dev
# the command below show the flags of gcc
sdl2-config --cflags --libs

or here

License and versions:

• Authors: [ . . . ]

• Version: 1.0.1

• License: GPL-3.0

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Pdf

Instructions for program: doc/robotica.pdf

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Functions

Funcs that are used in thread (working):

• source_rand

• make_robots

• set_to_draw

• draw

  In version 1.0, draw function shows on terminal. In version 1.1+ shows in window.

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Comments

@ppcamp:

To debug the threads you can use GBD:

Remember that, to debug your code, you need to use the -g flag when compiling.

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@ppcamp:

Useful commands to GDB:

• gdb a.out -- Start GDB;

• run -- Execute the runnable file 'a.out';

• backtrace -- Show last executions (frames);

• frame N -- Select frame N;

• print var -- Print some variable (e.g., from frame);

• kill -- Kill program running;

• break N -- BreakPoint. Showed in frame too;

• next -- Continue execution

  See more on: Unknow Road

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@ppcamp:

GDB commands to loop until get error

set $n = 100
while $n-- > 0
  printf "\n\n\n\t\tStarting program\n"
  run
  if $_siginfo
    printf "\n\n\n\t\tReceived signal %d, stopping\n", $_siginfo.si_signo
    loop_break
  else
    printf "\n\n\n\t\tProgram exited with Success!\n"
    end
end

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@ppcamp:

Debug functions:

void debug_buffer() {
 while (!buffer.empty()) {
   printf("Robot: %d, Source: %d, Pos: (%d,%d)\n", buffer.front().robot,
          buffer.front().source, buffer.front().x, buffer.front().y);
   buffer.pop();
 }
}

void debug_robots() {
 for (int i = 0; i < ROBOTS_AMOUNT; i++) {
   printf("Robot[%d]:\n", i);
   printf("\tSource mark: {%d,%d,%d}\n", robots[i].mark_equipament[0],
          robots[i].mark_equipament[1], robots[i].mark_equipament[2]);
   printf("\tPosition:\n");
   printf("\t\tSource [0]: (%d,%d)\n", robots[i].position[0][0],
          robots[i].position[0][1]);
   printf("\t\tSource [1]: (%d,%d)\n", robots[i].position[1][0],
          robots[i].position[1][1]);
   printf("\t\tSource [2]: (%d,%d)\n", robots[i].position[2][0],
          robots[i].position[2][1]);
 }
}

void debug_robots_to_draw() {
 for (int i = 0; i < ROBOTS_AMOUNT; i++) {
   printf("Draw robot %d:\n", i);
   printf("\tPos: (%d,%d)\n", robots_to_draw[i].x, robots_to_draw[i].y);
 }
}

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@ppcamp:

To compile SDL2 on linux:

./configure
make
sudo make install

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@ppcamp:

Some SDL2 tutorials links:

• LazyFoo
• Sonar

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