mandelbrot-mpi-dynamic.rar_MPI_MPI dynamic_Mandelbrot_mandelbrot

/* * MPI Mandelbrot program using dynamic task assignment * * This program computes and displays all or part of the Mandelbrot * set. By default, it examines all points in the complex plane * that have both real and imaginary parts between -2 and 2. * Command-line parameters allow zooming in on a specific part of * this range. * * Usage: * mandelbrot maxiter [x0 y0 size] * where * maxiter denotes the maximum number of iterations at each point * x0, y0, and size specify the range to examine (a square * centered at x0 + iy0 of size 2*size by 2*size -- by default, * a square of size 4 by 4 centered at the origin) * * Input: none, except the optional command-line arguments * Output: a graphical display as described in Wilkinson & Allen, * displayed using the X Window system, plus text output to * standard output showing the above parameters, plus execution * time in seconds. * * * Code originally obtained from Web site for Wilkinson and Allen's * text on parallel programming: * http://www.cs.uncc.edu/~abw/parallel/par_prog/ * * Reformatted and revised by B. Massingill. */ #include <stdio.h> #include <math.h> #include <stdlib.h> #include <unistd.h> #include <mpi.h> #include <X11/Xlib.h> #include <X11/Xutil.h> #include <X11/Xos.h> /* Default values for things. */ #define N 2 /* size of problem space (x, y from -N to N) */ #define NPIXELS 800 /* size of display window in pixels */ /* Constants for message-passing */ #define WORK_TAG 1 /* "work" message (master to worker) */ #define DATA_TAG 2 /* "data" message (worker to master) */ #define STOP_TAG 3 /* "stop" message (master to worker) */ /* Structure definition for complex numbers */ typedef struct { double real, imag; } complex; /* Functions for GUI */ #include "mandelbrot-gui.h" /* has setup(), interact() */ /* ---- Function declarations ---- */ int master_pgm(int nworkers, int width, int height, double real_min, double real_max, double imag_min, double imag_max, int maxiter); int worker_pgm(int myID, int width, int height, double real_min, double real_max, double imag_min, double imag_max, int maxiter); /* ---- Main program ---- */ int main (int argc, char *argv[]) { int nprocs; int myid; int returnval; int maxiter; double real_min = -N; double real_max = N; double imag_min = -N; double imag_max = N; int width = NPIXELS; /* dimensions of display window */ int height = NPIXELS; /* Initialize for MPI */ if (MPI_Init(&argc, &argv) != MPI_SUCCESS) { fprintf(stderr, "MPI initialization error\n"); exit(EXIT_FAILURE); } MPI_Comm_size(MPI_COMM_WORLD, &nprocs); MPI_Comm_rank(MPI_COMM_WORLD, &myid); if (nprocs < 2) { fprintf(stderr, "Number of processes must be at least 2\n"); MPI_Finalize(); exit(EXIT_FAILURE); } /* Check command-line arguments */ if ((argc < 2) || ((argc > 2) && (argc < 5))) { if (myid == 0) { fprintf(stderr, "usage: %s maxiter [x0 y0 size]\n", argv[0]); } MPI_Finalize(); exit(EXIT_FAILURE); } /* Process command-line arguments */ maxiter = atoi(argv[1]); if (argc > 2) { double x0 = atof(argv[2]); double y0 = atof(argv[3]); double size = atof(argv[4]); real_min = x0 - size; real_max = x0 + size; imag_min = y0 - size; imag_max = y0 + size; } /* Call master or worker code as appropriate */ if (myid == 0) { returnval = master_pgm(nprocs-1, width, height, real_min, real_max, imag_min, imag_max, maxiter); } else { returnval = worker_pgm(myid, width, height, real_min, real_max, imag_min, imag_max, maxiter); } /* Finish up */ MPI_Finalize(); return returnval; } /* * ---- Program for master process ---- * * Contains most code from original main program, slightly modified for MPI. * Returns EXIT_SUCCESS or EXIT_FAILURE as appropriate. */ int master_pgm(int nworkers, int width, int height, double real_min, double real_max, double imag_min, double imag_max, int maxiter) { Display *display; Window win; GC gc; long min_color, max_color; int this_row, next_row; int p; double start_time, end_time; long *data_msg = malloc((width+1) * sizeof(long)); MPI_Status status; int col; int tasks_not_done; int id; int setup_return; /* Initialize for graphical display */ setup_return = setup(width, height, &display, &win, &gc, &min_color, &max_color); if (setup_return != EXIT_SUCCESS) { fprintf(stderr, "Unable to initialize display, continuing\n"); } /* (if not successful, continue but don't display results) */ /* Start timing */ start_time = MPI_Wtime(); /* START OF CHANGED SECTION */ /* Broadcast values workers will need and can't compute */ MPI_Bcast(&min_color, 1, MPI_LONG, 0, MPI_COMM_WORLD); MPI_Bcast(&max_color, 1, MPI_LONG, 0, MPI_COMM_WORLD); /* Set up for dynamic task assignment */ next_row = 0; /* next row to assign to a worker */ tasks_not_done = 0; /* count of workers still working */ /* Send each worker first row to work on */ for (p = 0; p < nworkers; ++p) { MPI_Send(&next_row, 1, MPI_INT, p+1, WORK_TAG, MPI_COMM_WORLD); ++next_row; ++tasks_not_done; } /* Receive results from workers and draw points */ while (tasks_not_done > 0) { /* Receive a row from a worker */ MPI_Recv(data_msg, width+1, MPI_LONG, MPI_ANY_SOURCE, DATA_TAG, MPI_COMM_WORLD, &status); --tasks_not_done; id = status.MPI_SOURCE; /* More rows? */ if (next_row < height) { /* If so, give this worker another row to work on */ MPI_Send(&next_row, 1, MPI_INT, id, WORK_TAG, MPI_COMM_WORLD); ++next_row; ++tasks_not_done; } else { /* Otherwise shut this worker down */ MPI_Send(&next_row, 0, MPI_INT, id, STOP_TAG, MPI_COMM_WORLD); } /* Display received data */ this_row = data_msg[0]; for (col = 0; col < width; ++col) { if (setup_return == EXIT_SUCCESS) { XSetForeground (display, gc, data_msg[col+1]); XDrawPoint (display, win, gc, col, this_row); } } } /* END OF CHANGED SECTION */ /* Be sure everything is written out. */ if (setup_return == EXIT_SUCCESS) { XFlush (display); } /* End timing */ end_time = MPI_Wtime(); /* Produce text output */ fprintf(stdout, "\n"); fprintf(stdout, "MPI program with dynamic task assignment\n"); fprintf(stdout, "number of worker processes = %d\n", nworkers); fprintf(stdout, "center = (%g, %g), size = %g\n", (real_max + real_min)/2, (imag_max + imag_min)/2, (real_max - real_min)/2); fprintf(stdout, "maximum iterations = %d\n", maxiter); fprintf(stdout, "execution time in seconds = %g\n", end_time - start_time); fprintf(stdout, "\n"); /* Wait for user response, then exit program */ if (setup_return == EXIT_SUCCESS) { interact(display, &win, width, height, real_min, real_max, imag_min, imag_max); } free(data_msg); return EXIT_SUCCESS; } /* * ---- Program for worker process ---- * * Returns EXIT_SUCCESS or EXIT_FAILURE as appropriate. */ int worker_pgm(int myID, int width, int height, double real_min, double real_max, double imag_min, double imag_max, int maxiter) { MPI_Status status; int the_row; long min_color, max_color, color; double scale_real, scale_imag, scale_color; long *data_msg =