6 * @author Sam Moore (205030628)
7 * @purpose N-Body simulator: declarations of simulation related parameters
14 #include <sys/time.h> //POSIX time
18 #define SINGLE_THREADED
20 //These macros will be undefined by the multithreaded versions
21 #define Simulation_Run() //Sets up the simulation; in multithreaded versions, will spawn threads
22 #define QuitProgram(error) (runstate = (error == true) ? QUIT : QUIT_ERROR) //Prepares to exit program, is thread safe in multithreaded versions
24 #define M_PI 3.14159265358979323846264338327950288 /* pi */
28 #define square(x) ((x)*(x))
32 * Structure to represent a single Body
33 * @param mass - Mass of the body
34 * @param x - Position vector (array)
35 * @param v - Velocity vector (array)
36 * @param F - Net force vector (array)
49 * Structure to store an array of bodies, along with the size of the array.
50 * The universe is represented by a single System.
51 * In the multithreaded program, the universe is subdivided into one system for each working thread to use.
52 * @param N - Size of the array
53 * @param body - The array of bodies
57 unsigned N; // Number of bodies in the System
58 Body * body; // Array of bodies
60 unsigned steps; //Number of steps simulated
65 * Structure to represent options passed to the program.
69 const char * input; // initial body field
70 const char * output; // file to write final positions / velocities of bodies to
71 const char * program; // program name
72 unsigned num_threads; // number of worker threads to spawn (must be greater than 1 for any to be spawned)
73 unsigned num_steps; // number of steps to run before stopping (run indefinately if equal to zero)
74 unsigned timeout; // number of seconds to run before stopping (run indefinately if equal to zero)
75 bool draw_graphics; // whether or not to actually draw graphics
76 bool print_positions; // print positions of bodies to stdout on every step
77 unsigned verbosity; // print statistics every number of steps indicated by this variable
78 clock_t start_clock; // clock cycles done when simulation starts
79 struct timeval start_time; // time at which simulation starts
82 void Body_Print(Body * a, FILE * out); //Print body a
83 void Body_Force(Body * a, System * s); //Compute force on body a due to system of bodies s
84 void Body_Velocity(Body * a); //Compute velocity of body a
85 void Body_Position(Body * a); //Compute position of body a
87 void System_Init(System * s, const char * fileName); //Initialise System (array of bodies) from a text file
88 void System_Compute(System * s);
89 void System_Forces(System * s1, System * s2); //Compute forces for bodies in s1 due to bodies in s2 (also updates velocities)
90 void System_Positions(System * s); //Update positions for bodies in s1
93 void Universe_Cleanup(); //Cleanup universe and write bodies to file
95 void DisplayStatistics(); // Print information about steps computed, total (real) runtime, and CPU cycles
99 typedef enum {RUN, QUIT, QUIT_ERROR} RUNSTATE;
100 extern RUNSTATE runstate; // Set runstate to QUIT or QUIT_ERROR and the simulation will stop on the next step.
101 // This is fairly redundant in the single threaded version, but useful for making sure *all* threads know to exit in the multi-threaded version
104 extern System universe; // The main array of bodies; global variable.
105 extern Options options; // Parameters passed to program