Game of Life in C and MPI
--D. Thiebaut (talk) 23:25, 8 March 2017 (EST)
Contents
Serial Game of Life
Source, Version 1
/* Game of life D. Thiebaut Heavily adapted from code found in java section at this URL: https://rosettacode.org/wiki/Conway%27s_Game_of_Life#Java and ported to C. This code works in console mode, displaying successive generations of the game of life on the screen, and clearing the screen between each one. The initial pattern is defined in the array dish (as in petri dish). To compile and run: gcc -o GameOfLife GameOfLife.c ./GameOfLife */ #include <stdio.h> #include <string.h> #include <stdlib.h> #include <time.h> #include <unistd.h> // ------------------------------------- MACROS ---------------------------------------- #define NUMBERROWS 28 #define esc 27 #define cls() printf("%c[2J",esc) #define pos(row,col) printf("%c[%d;%dH",esc,row,col) // ------------------------------------- GLOBALS ---------------------------------------- char *DISH0[ NUMBERROWS ]; char *DISH1[ NUMBERROWS ]; char *PATTERN[NUMBERROWS] = { " ", " # ", " # # ### ", " ## ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " " }; // --------------------------------- prototypes ----------------------------- void life( char**, char** ); void initDishes( ); void clearScreen(); void print( char ** ); // -------------------------------------------------------------------------- // initDishes // inits the dishes (current and future) void initDishes( ) { int i; //--- initialize other dish with spaces. Make it same dimension as DISH0. --- for (i = 0; i< NUMBERROWS; i++ ) { DISH0[i] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[i], PATTERN[i] ); DISH1[i] = (char *) malloc( (strlen( DISH0[0] )+1) * sizeof( char ) ); strcpy( DISH1[i], DISH0[i] ); } } // -------------------------------------------------------------------------- // clearscreen: void clearScreen() { /* * brings the cursor home (top-left), so that the next generation will * be printed over the current one. */ char ANSI_CLS[] = "\x1b[2J"; char ANSI_HOME[] = "\x1b[H"; printf( "%s%s", ANSI_HOME, ANSI_CLS ); } // -------------------------------------------------------------------------- // print void print( char* dish[] ) { /* * just display all the lines of the array of strings. */ int i; for (i=0; i<NUMBERROWS; i++ ) { pos( i, 0 ); printf( "%s\n", dish[i] ); } } // -------------------------------------------------------------------------- void life( char** dish, char** newGen ) { /* * Given an array of string representing the current population of cells * in a petri dish, computes the new generation of cells according to * the rules of the game. A new array of strings is returned. */ int i, j, row; int rowLength = strlen( dish[0] ); int dishLength = NUMBERROWS; for (row = 0; row < NUMBERROWS; row++) {// each row for ( i = 0; i < rowLength; i++) { // each char in the // row int r, j, neighbors = 0; char current = dish[row][i]; // loop in a block that is 3x3 around the current cell // and count the number of '#' cells. for ( r = row - 1; r <= row + 1; r++) { // make sure we wrap around from bottom to top int realr = r; if (r == -1) realr = dishLength - 1; if (r == dishLength) realr = 0; for ( j = i - 1; j <= i + 1; j++) { // make sure we wrap around from left to right int realj = j; if (j == -1) realj = rowLength - 1; if (j == rowLength) realj = 0; if (r == row && j == i) continue; // current cell is not its // neighbor if (dish[realr][realj] == '#') neighbors++; } } if (current == '#') { if (neighbors < 2 || neighbors > 3) newGen[row][i] = ' '; else newGen[row][i] = '#'; } if (current == ' ') { if (neighbors == 3) newGen[row][i] = '#'; else newGen[row][i] = ' '; } } } } // -------------------------------------------------------------------------- int main( int argc, char* argv[] ) { int gens = 3000; // # of generations int i; char **dish, **future, **temp; //--- clear screen --- cls(); //--- init the global arrays --- initDishes(); //--- set pointers to them --- dish = DISH0; future = DISH1; //--- print first generation --- print( dish ); //--- iterate over all generations --- for ( i = 0; i < gens; i++) { //printf( "Generation %d\n", i ); // apply the rules of life to the current population and // generate the next generation. life( dish, future ); // display the new generation (comment this out if you want // the last generation, instead) print( dish ); // add a bit of a delay to better see the visualization // remove this part to get full timing. sleep(1); // 1 sec // copy future to dish temp = dish; dish = future; future = temp; } // display the last generation print(dish); }
Output
# # ## # # # ## ## # # ## ## # # # # # # # # # ## ## # # # # ## # # ## # # # # ## # # ### # # # # ## # # ## # ## 352b@aurora ~/handout/mpi $
Source, Version 2
This version reads the initial dish from a data file whose name is provided on the command line. This version also reports the execution time of the program without displaying the generations.
Execution times on a MacBook Pro 2016 for a 3000 generations of a game of life with a 2048-line dish of 80-char long lines: 20.98246 sec, 21.08754 sec, and 20.79234 sec.
/* Game of life (V2) D. Thiebaut Heavily adapted from code found in java section at this URL: https://rosettacode.org/wiki/Conway%27s_Game_of_Life#Java and ported to C. This code works in console mode, computing 3000 generations of a game of life provided in a dish that is originally read from a data file. To compile and run: gcc -o GameOfLife2 GameOfLife2.c ./GameOfLife2 dishFileName */ #include <stdio.h> #include <strings.h> #include <stdlib.h> #include <time.h> #include <unistd.h> // ------------------------------------- MACROS ---------------------------------------- #define esc 27 #define cls() printf("%c[2J",esc) #define pos(row,col) printf("%c[%d;%dH",esc,row,col) // ------------------------------------- GLOBALS ---------------------------------------- int NUMBERROWS; char **DISH0; char **DISH1; // --------------------------------- prototypes ----------------------------- void life( char**, char** ); void initDishes( char* ); void clearScreen(); void print( char ** ); // -------------------------------------------------------------------------- // initDishes // inits the dishes (current and future) void initDishes( char* fileName ) { int i, n; char ch, buffer[1000]; //--- read # of lines first --- FILE *f = fopen( fileName, "r" ); int noLines = 0; while ( !feof( f ) ) { ch = fgetc( f ); if (ch == '\n') noLines++; } fclose( f ); //--- set global --- NUMBERROWS = noLines; //printf( "number of lines = %d\n", noLines ); //--- initialize DISH arrays --- DISH0 = (char **) malloc( noLines * sizeof( char* ) ); DISH1 = (char **) malloc( noLines * sizeof( char* ) ); //--- read file again and initialize arrays --- f = fopen( fileName, "r" ); i = 0; while ( !feof( f ) ) { fgets( buffer, 1000, f ); if ( feof( f ) ) break; buffer[999] = '\0'; DISH0[i] = (char *) malloc( (strlen( buffer) + 1 ) * sizeof( char ) ); strcpy( DISH0[i], buffer ); DISH1[i] = (char *) malloc( (strlen( DISH0[i] ) + 1 ) * sizeof( char ) ); strcpy( DISH1[i], DISH0[i] ); i++; } fclose( f ); } // -------------------------------------------------------------------------- // clearscreen: void clearScreen() { /* * brings the cursor home (top-left), so that the next generation will * be printed over the current one. */ return; char ANSI_CLS[] = "\x1b[2J"; char ANSI_HOME[] = "\x1b[H"; printf( "%s%s", ANSI_HOME, ANSI_CLS ); } // -------------------------------------------------------------------------- // print void print( char* dish[] ) { /* * just display all the lines of the array of strings. */ int i; for (i=0; i<NUMBERROWS; i++ ) { pos( i, 0 ); printf( "%s\n", dish[i] ); } } // -------------------------------------------------------------------------- void check( char** dish, char** future ) { int i, j, k, l; l = sizeof( dish )/sizeof( dish[0] ); printf( "length of dish = %d\n", l ); for ( i=0; i<l; i++ ) { k = strlen( dish[i] ); printf( "%d %s\n", k, dish[i] ); } printf( "\n\n" ); l = sizeof( future )/sizeof( future[0] ); printf( "length of future = %d\n", l ); for ( i=0; i<l; i++ ) { k = strlen( future[i] ); printf( "%d %s\n", k, future[i] ); } printf( "\n\n" ); } // -------------------------------------------------------------------------- void life( char** dish, char** newGen ) { /* * Given an array of string representing the current population of cells * in a petri dish, computes the new generation of cells according to * the rules of the game. A new array of strings is returned. */ int i, j, row; int rowLength = strlen( dish[0] ); int dishLength = NUMBERROWS; for (row = 0; row < NUMBERROWS; row++) {// each row for ( i = 0; i < rowLength; i++) { // each char in the // row int r, j, neighbors = 0; char current = dish[row][i]; // loop in a block that is 3x3 around the current cell // and count the number of '#' cells. for ( r = row - 1; r <= row + 1; r++) { // make sure we wrap around from bottom to top int realr = r; if (r == -1) realr = dishLength - 1; if (r == dishLength) realr = 0; for (int j = i - 1; j <= i + 1; j++) { // make sure we wrap around from left to right int realj = j; if (j == -1) realj = rowLength - 1; if (j == rowLength) realj = 0; if (r == row && j == i) continue; // current cell is not its // neighbor if (dish[realr][realj] == '#') neighbors++; } } if (current == '#') { if (neighbors < 2 || neighbors > 3) newGen[row][i] = ' '; else newGen[row][i] = '#'; } if (current == ' ') { if (neighbors == 3) newGen[row][i] = '#'; else newGen[row][i] = ' '; } } } } // -------------------------------------------------------------------------- int main( int argc, char* argv[] ) { int gens = 3000; // # of generations int i; char **dish, **future, **temp; char *fileName; unsigned long micros = 0; clock_t startTime, endTime; if ( argc < 2 ) { printf( "Syntax: ./GameOfLife2 dishFileName\n\n" ); return 1; } //--- get the file name from the command line --- fileName = argv[1]; //--- clear screen --- //cls(); //--- init the global arrays --- initDishes( fileName ); //--- start measuring time --- startTime = clock(); //--- set pointers to them --- dish = DISH0; future = DISH1; //--- for debugging --- //check( dish, future ); //--- print first generation --- //print( dish ); //--- iterate over all generations --- for ( i = 0; i < gens; i++) { //printf( "Generation %d\n", i ); // apply the rules of life to the current population and // generate the next generation. life( dish, future ); // display the new generation (comment this out if you want // the last generation, instead) //print( dish ); // add a bit of a delay to better see the visualization // remove this part to get full timing. //sleep(1); // 1 sec // copy future to dish temp = dish; dish = future; future = temp; } // display the last generation //print(dish); //--- measure elapsed time --- endTime = clock(); float seconds = (endTime - startTime)/1000000.0; printf( "%1.5f\n", seconds ); }
MPI Version of Game of Life, in C
Source
/* Game of life D. Thiebaut This is the MPI version of GameOfLife.c, for MPI, for 2 Processes, or tasks. This version works only for 2 tasks. It hasn't been optimized. Each task works on one half of the dish arrays where the generations evolve, but actually maintain a full array in memory. The two tasks communicate with each other after each generation and exchange 2 rows, each. This code works in console mode, displaying successive generations of the game of life on the screen, and clearing the screen between each one. The initial pattern is defined in the array PATTERN. To compile and run, several different variants: mpicc.mpich -o GameOfLifeMPI2 GameOfLifeMPI2.c mpiexec.mpich -n 2 ./GameOfLifeMPI2 or mpicc -o GameOfLifeMPI2 GameOfLifeMPI2.c mpirun -np 2 ./GameOfLifeMPI2 */ #include <stdio.h> #include <strings.h> #include <stdlib.h> #include <time.h> #include <unistd.h> #include "mpi.h" #define NUMBERROWS 28 #define esc 27 #define cls() printf("%c[2J",esc) #define pos(row,col) printf("%c[%d;%dH",esc,row,col) char *DISH0[ NUMBERROWS ]; char *DISH1[ NUMBERROWS ]; char *PATTERN[NUMBERROWS] = { " ", " # ", " # # ### ", " ## ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " # ", " # # ", " ## ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " ", " " }; int ROWSIZE = strlen( " ") + 1; //------------------------------- prototypes -------------------------------- void life( char**, char**, int ); void initDishes( int ); void print( char **, int ); // -------------------------------------------------------------------------- // initDishes // inits the dishes (current and future) void initDishes( int rank ) { int i; //--- initialize other dish with spaces. Make it same dimension as DISH0. --- for (i = 0; i< NUMBERROWS; i++ ) { DISH0[i] = (char *) malloc( ( strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[i], PATTERN[i] ); DISH1[i] = (char *) malloc( (strlen( DISH0[0] )+1) * sizeof( char ) ); strcpy( DISH1[i], PATTERN[i] ); } } // -------------------------------------------------------------------------- // initDishes2 // inits the dishes (current and future) // (Buggy: attempts to declare only 1 half of the array, plus boundary // rows, depending on rank. Needs a bit more debugging...) void initDishes2( int rank ) { int i; // init to null all entries. This way we'll be // able to tell if a row belongs to us or not. for ( i=0; i<NUMBERROWS; i++ ) { DISH0[i] = NULL; DISH1[i] = NULL; } //--- Init RANK 0 rows --- if ( rank == 0 ) { //--- initialize dishes with lower half of pattern --- for (i = 0; i< NUMBERROWS/2+1; i++ ) { DISH0[i] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[i], PATTERN[i] ); DISH1[i] = (char *) malloc( (strlen( DISH0[0] )+1) * sizeof( char ) ); strcpy( DISH1[i], DISH0[i] ); } //--- initialize top row of dishes, as they are neighbors of Row 0 --- DISH0[NUMBERROWS-1] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[NUMBERROWS-1], PATTERN[NUMBERROWS-1] ); DISH1[NUMBERROWS-1] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH1[NUMBERROWS-1], PATTERN[NUMBERROWS-1] ); } //--- Init RANK 1 rows --- if ( rank == 1 ) { //--- initialize dishes with upper half of pattern --- for (i = NUMBERROWS/2-1; i< NUMBERROWS; i++ ) { DISH0[i] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[i], PATTERN[i] ); DISH1[i] = (char *) malloc( (strlen( DISH0[0] )+1) * sizeof( char ) ); strcpy( DISH1[i], DISH0[i] ); } //--- initialize bottom row of dishes, as they are neighbors of top row --- DISH0[0] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH0[0], PATTERN[0] ); DISH1[0] = (char *) malloc( (strlen( PATTERN[0] ) + 1 ) * sizeof( char ) ); strcpy( DISH1[0], PATTERN[01] ); } } // -------------------------------------------------------------------------- // print void print( char* dish[], int rank ) { int i; if ( rank == 0 ) { //--- display lower half only --- for (i=0; i<NUMBERROWS/2; i++ ) { if ( dish[i] == NULL ) continue; pos( i, 0 ); printf( "%s\n", dish[i] ); } } if ( rank == 1 ) { //--- display upper half only --- for (i=NUMBERROWS/2; i<NUMBERROWS; i++ ) { if ( dish[i] == NULL ) continue; pos( i, 0 ); printf( "%s\n", dish[i] ); } } } // -------------------------------------------------------------------------- void check( char** dish, char** future ) { int i, j, k, l; l = sizeof( dish )/sizeof( dish[0] ); printf( "length of dish = %d\n", l ); for ( i=0; i<l; i++ ) { k = strlen( dish[i] ); printf( "%d %s\n", k, dish[i] ); } printf( "\n\n" ); l = sizeof( future )/sizeof( future[0] ); printf( "length of future = %d\n", l ); for ( i=0; i<l; i++ ) { k = strlen( future[i] ); printf( "%d %s\n", k, future[i] ); } printf( "\n\n" ); } // -------------------------------------------------------------------------- void life( char** dish, char** newGen, int rank ) { /* * Given an array of string representing the current population of cells * in a petri dish, computes the new generation of cells according to * the rules of the game. A new array of strings is returned. */ int i, j, row; int rowLength = strlen( dish[0] ); int dishLength = NUMBERROWS; int lowerRow, upperRow; //--- slice the array into two halves. Rank 0 is lower half, --- //-- Rank 1 is upper half. --- if ( rank == 0 ) { lowerRow = 0; upperRow = NUMBERROWS/2; } if ( rank == 1 ) { lowerRow = NUMBERROWS/2; upperRow = NUMBERROWS; } for (row = lowerRow; row < upperRow; row++) {// each row if ( dish[row] == NULL ) continue; for ( i = 0; i < rowLength; i++) { // each char in the // row int r, j, neighbors = 0; char current = dish[row][i]; // loop in a block that is 3x3 around the current cell // and count the number of '#' cells. for ( r = row - 1; r <= row + 1; r++) { // make sure we wrap around from bottom to top int realr = r; if (r == -1) realr = dishLength - 1; if (r == dishLength) realr = 0; for (int j = i - 1; j <= i + 1; j++) { // make sure we wrap around from left to right int realj = j; if (j == -1) realj = rowLength - 1; if (j == rowLength) realj = 0; if (r == row && j == i) continue; // current cell is not its // neighbor if (dish[realr][realj] == '#') neighbors++; } } if (current == '#') { if (neighbors < 2 || neighbors > 3) newGen[row][i] = ' '; else newGen[row][i] = '#'; } if (current == ' ') { if (neighbors == 3) newGen[row][i] = '#'; else newGen[row][i] = ' '; } } } } // -------------------------------------------------------------------------- int main( int argc, char* argv[] ) { int gens = 3000; // # of generations int i; char **dish, **future, **temp; //--- MPI Variables --- int noTasks = 0; int rank = 0; MPI_Status status; // required variable for receive routines //--- initialize MPI --- MPI_Init( &argc, &argv ); //--- get number of tasks, and make sure it's 2 --- MPI_Comm_size( MPI_COMM_WORLD, &noTasks ); if ( noTasks != 2 ) { printf( "Number of Processes/Tasks must be 2. Number = %d\n\n", noTasks ); MPI_Finalize(); return 1; } //--- get rank --- MPI_Comm_rank( MPI_COMM_WORLD, &rank ); //--- init the dishes as half of the original problem --- initDishes( rank ); dish = DISH0; future = DISH1; //check( dish, future ); //--- clear screen --- cls(); print( dish, rank ); // # first generation, in petri dish // iterate over all generations for ( i = 0; i < gens; i++) { pos( 33+rank, 0 ); printf( "Rank %d: Generation %d\n", rank, i ); // apply the rules of life to the current population and // generate the next generation. life( dish, future, rank ); // display the new generation //print( dish, rank ); // add a bit of a delay to better see the visualization // remove this part to get full timing. //if (rank == 0 ) sleep( 1 ); if (rank==0 ) { // buffer #items item-size src/dest tag world MPI_Send( future[ 0 ], ROWSIZE, MPI_CHAR, 1, 0, MPI_COMM_WORLD ); MPI_Send( future[NUMBERROWS/2-1], ROWSIZE, MPI_CHAR, 1, 0, MPI_COMM_WORLD ); MPI_Recv( future[NUMBERROWS-1], ROWSIZE, MPI_CHAR, 1, 0, MPI_COMM_WORLD, &status ); MPI_Recv( future[NUMBERROWS/2], ROWSIZE, MPI_CHAR, 1, 0, MPI_COMM_WORLD, &status ); } if (rank==1 ) { MPI_Recv( future[ 0 ], ROWSIZE, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status ); MPI_Recv( future[NUMBERROWS/2-1], ROWSIZE, MPI_CHAR, 0, 0, MPI_COMM_WORLD, &status ); MPI_Send( future[NUMBERROWS-1], ROWSIZE, MPI_CHAR, 0, 0, MPI_COMM_WORLD ); MPI_Send( future[NUMBERROWS/2], ROWSIZE, MPI_CHAR, 0, 0, MPI_COMM_WORLD ); } // copy future to dish temp = dish; dish = future; future = temp; } //--- display the last generation --- print(dish, rank); //--- close MPI --- pos( 30+rank, 0 ); printf( "Process %d done. Exiting\n\n", rank ); MPI_Finalize(); return 0; }
Output
# # ## # # # ## ## # # ## ## # # # # # # # # # ## ## # # # # ## # # ## # # # # ## # # ### # # # # ## # # ## # ## Process 0 done. Exiting Process 1 done. Exiting 352b@aurora ~/handout/mpi $
