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ex3: style

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This commit is contained in:
Fredrik Robertsen
2025-09-22 16:28:44 +02:00
parent 09e4c6be47
commit ef1b6f58a0
1 changed files with 88 additions and 118 deletions
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206
exercise3/wave_1d_parallel.c
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@@ -1,9 +1,9 @@
#define _XOPEN_SOURCE 600
#include <math.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <math.h>
#include <sys/time.h>
// TASK: T1a
@@ -12,19 +12,16 @@
;
// END: T1a
// Option to change numerical precision.
typedef int64_t int_t;
typedef double real_t;
// TASK: T1b
// Declare variables each MPI process will need
// BEGIN: T1b
;
// END: T1b
// Simulation parameters: size, step count, and how often to save the state.
const int_t
N = 65536,
@@ -33,7 +30,7 @@ const int_t
// Wave equation parameters, time step is derived from the space step.
const real_t
c = 1.0,
c = 1.0,
dx = 1.0;
real_t
dt;
@@ -42,164 +39,137 @@ real_t
real_t
*buffers[3] = { NULL, NULL, NULL };
#define U_prv(i) buffers[0][(i)+1]
#define U(i) buffers[1][(i)+1]
#define U_nxt(i) buffers[2][(i)+1]
#define U_prv(i) buffers[0][(i) + 1]
#define U(i) buffers[1][(i) + 1]
#define U_nxt(i) buffers[2][(i) + 1]
// Convert 'struct timeval' into seconds in double prec. floating point
#define WALLTIME(t) ((double)(t).tv_sec + 1e-6 * (double)(t).tv_usec)
// TASK: T8
// Save the present time step in a numbered file under 'data/'.
void domain_save ( int_t step )
{
// BEGIN: T8
char filename[256];
sprintf ( filename, "data/%.5ld.dat", step );
FILE *out = fopen ( filename, "wb" );
fwrite ( &U(0), sizeof(real_t), N, out );
fclose ( out );
// END: T8
void domain_save(int_t step) {
// BEGIN: T8
char filename[256];
sprintf(filename, "data/%.5ld.dat", step);
FILE *out = fopen(filename, "wb");
fwrite(&U(0), sizeof(real_t), N, out);
fclose(out);
// END: T8
}
// TASK: T3
// Allocate space for each process' sub-grids
// Set up our three buffers, fill two with an initial cosine wave,
// and set the time step.
void domain_initialize ( void )
{
// BEGIN: T3
buffers[0] = malloc ( (N+2)*sizeof(real_t) );
buffers[1] = malloc ( (N+2)*sizeof(real_t) );
buffers[2] = malloc ( (N+2)*sizeof(real_t) );
void domain_initialize(void) {
// BEGIN: T3
buffers[0] = malloc((N + 2) * sizeof(real_t));
buffers[1] = malloc((N + 2) * sizeof(real_t));
buffers[2] = malloc((N + 2) * sizeof(real_t));
for ( int_t i=0; i<N; i++ )
{
U_prv(i) = U(i) = cos ( 2*M_PI*i / (real_t)N );
}
// END: T3
for (int_t i = 0; i < N; i++) {
U_prv(i) = U(i) = cos(2 * M_PI * i / (real_t)N);
}
// END: T3
// Set the time step for 1D case.
dt = dx / c;
// Set the time step for 1D case.
dt = dx / c;
}
// Return the memory to the OS.
void domain_finalize ( void )
{
free ( buffers[0] );
free ( buffers[1] );
free ( buffers[2] );
void domain_finalize(void) {
free(buffers[0]);
free(buffers[1]);
free(buffers[2]);
}
// Rotate the time step buffers.
void move_buffer_window ( void )
{
real_t *temp = buffers[0];
buffers[0] = buffers[1];
buffers[1] = buffers[2];
buffers[2] = temp;
void move_buffer_window(void) {
real_t *temp = buffers[0];
buffers[0] = buffers[1];
buffers[1] = buffers[2];
buffers[2] = temp;
}
// TASK: T4
// Derive step t+1 from steps t and t-1.
void time_step ( void )
{
// BEGIN: T4
for ( int_t i=0; i<N; i++ )
{
U_nxt(i) = -U_prv(i) + 2.0*U(i)
+ (dt*dt*c*c)/(dx*dx) * (U(i-1)+U(i+1)-2.0*U(i));
}
// END: T4
void time_step(void) {
// BEGIN: T4
for (int_t i = 0; i < N; i++) {
U_nxt(i) = -U_prv(i) + 2.0 * U(i) + (dt * dt * c * c) / (dx * dx) * (U(i - 1) + U(i + 1) - 2.0 * U(i));
}
// END: T4
}
// TASK: T6
// Neumann (reflective) boundary condition.
void boundary_condition ( void )
{
// BEGIN: T6
U(-1) = U(1);
U(N) = U(N-2);
// END: T6
void boundary_condition(void) {
// BEGIN: T6
U(-1) = U(1);
U(N) = U(N - 2);
// END: T6
}
// TASK: T5
// Communicate the border between processes.
void border_exchange( void )
{
// BEGIN: T5
;
// END: T5
void border_exchange(void) {
// BEGIN: T5
;
// END: T5
}
// TASK: T7
// Every process needs to communicate its results
// to root and assemble it in the root buffer
void send_data_to_root()
{
// BEGIN: T7
;
// END: T7
void send_data_to_root() {
// BEGIN: T7
;
// END: T7
}
// Main time integration.
void simulate( void )
{
// Go through each time step.
for ( int_t iteration=0; iteration<=max_iteration; iteration++ )
{
if ( (iteration % snapshot_freq)==0 )
{
send_data_to_root();
domain_save ( iteration / snapshot_freq );
}
// Derive step t+1 from steps t and t-1.
border_exchange();
boundary_condition();
time_step();
move_buffer_window();
void simulate(void) {
// Go through each time step.
for (int_t iteration = 0; iteration <= max_iteration; iteration++) {
if ((iteration % snapshot_freq) == 0) {
send_data_to_root();
domain_save(iteration / snapshot_freq);
}
// Derive step t+1 from steps t and t-1.
border_exchange();
boundary_condition();
time_step();
move_buffer_window();
}
}
int main(int argc, char **argv) {
// TASK: T1c
// Initialise MPI
// BEGIN: T1c
;
// END: T1c
int main ( int argc, char **argv )
{
// TASK: T1c
// Initialise MPI
// BEGIN: T1c
;
// END: T1c
struct timeval t_start, t_end;
struct timeval t_start, t_end;
domain_initialize();
domain_initialize();
// TASK: T2
// Time your code
// BEGIN: T2
simulate();
// END: T2
domain_finalize();
// TASK: T2
// Time your code
// BEGIN: T2
simulate();
// END: T2
// TASK: T1d
// Finalise MPI
// BEGIN: T1d
;
// END: T1d
domain_finalize();
exit ( EXIT_SUCCESS );
// TASK: T1d
// Finalise MPI
// BEGIN: T1d
;
// END: T1d
exit(EXIT_SUCCESS);
}