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Language/OS - Multiplatform Resource Library
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LANGUAGE OS.iso
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p4
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p4-1_2c.lha
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p4-1.2c
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monitors
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grid.shmem.c
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C/C++ Source or Header
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1993-05-24
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6KB
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265 lines
#include "p4.h"
#define ROWS 200
#define COLUMNS 200
struct globmem {
double a[ROWS+2][COLUMNS+2];
double b[ROWS+2][COLUMNS+2];
int st[ROWS+2], pq[ROWS+1];
int pqbeg, pqend, goal, nproc, rows, columns;
p4_askfor_monitor_t MO;
p4_barrier_monitor_t BA;
} *glob;
double avggrid();
double avgbnd();
slave()
{
work('s');
}
phi(x,y) /* The function on the boundary */
int x,y;
{
return((x * x) - (y * y) + (x * y));
}
main(argc,argv)
int argc;
char **argv;
{
int i;
int timestart, timeend;
p4_usc_time_t start_ustime, end_ustime;
double avg;
p4_initenv(&argc,argv);
glob = (struct globmem *) p4_shmalloc(sizeof(struct globmem));
p4_askfor_init(&(glob->MO));
p4_barrier_init(&(glob->BA));
printf("enter number of processes: ");
scanf("%d",&glob->nproc);
printf("enter the number of rows: ");
scanf("%d",&glob->rows);
printf("enter the number of columns: ");
scanf("%d",&glob->columns);
printf("enter the number of iterations: ");
scanf("%d",&glob->goal);
gridinit(glob->a,glob->rows,glob->columns);
gridinit(glob->b,glob->rows,glob->columns);
glob->pqbeg = glob->pqend = 0;
for (i=1; i <= glob->rows; i++)
queueprob(i);
/* initialize the status vector */
for (i=0; i < (glob->rows+2); i++)
glob->st[i] = 0;
printf("\nnproc\tgoal\trows\tcolumns\n");
printf("%d \t %d \t %d \t %d \n",
glob->nproc,glob->goal,glob->rows,glob->columns);
for (i=1; i <= glob->nproc-1; i++) {
p4_create(slave);
}
timestart = p4_clock();
start_ustime = p4_ustimer();
work('m');
end_ustime = p4_ustimer();
timeend = p4_clock();
printf("total time %.3f seconds\n",(timeend - timestart)/1000.0);
printf("total time %.6f seconds\n",(end_ustime-start_ustime)/1000000.0);
/*
printf("the resulting grid:\n");
if (glob->goal % 2 == 0)
printgrid(glob->a,glob->rows,glob->columns);
else
printgrid(glob->b,glob->rows,glob->columns);
*/
if (glob->goal % 2 == 0)
avg = avggrid(glob->a,glob->rows,glob->columns);
else
avg = avggrid(glob->b,glob->rows,glob->columns);
printf("average value of grid = %f\n",avg);
p4_wait_for_end();
}
/* "m" is the matrix, "r" is the number of rows of data (m[1]-m[r];
m[0] and m[r+1] are boundaries), and "c" is the number of columns
of data.
*/
gridinit(m,r,c)
double m[ROWS+2][COLUMNS+2];
int r, c;
{
int i, j;
double bndavg;
for (j=0; j < (c + 2); j++)
{
m[0][j] = phi(1,j+1);
m[r+1][j]= phi(r+2,j+1);
}
for (i=1; i < (r + 2); i++)
{
m[i][0] = phi(i+1,1);
m[i][c+1] = phi(i+1,c+2);
}
bndavg = avgbnd(m,r,c);
printf("boundary average = %f\n",bndavg);
/* initialize the interior of the grids to the average over the boundary*/
for (i=1; i <= r; i++)
for (j=1; j <= c; j++)
/* m[i][j] = bndavg; this optimization hinders debugging */
m[i][j] = 0;
}
queueprob(x)
int x;
{
glob->pq[glob->pqend] = x;
glob->pqend = (glob->pqend + 1) % (ROWS + 1);
}
compute(p,q,r,columns)
double p[ROWS+2][COLUMNS+2];
double q[ROWS+2][COLUMNS+2];
int r;
int columns;
{
int j;
for (j = 1; j <= columns; j++)
q[r][j] = (p[r-1][j] + p[r+1][j] + p[r][j-1] + p[r][j+1]) / 4.0;
}
int putprob(r)
int r;
{
int qprob;
qprob = FALSE;
glob->st[r]++;
if (r == 1)
glob->st[0] = glob->st[r];
else if (r == glob->rows)
glob->st[glob->rows+1] = glob->st[r];
if (glob->st[r] < glob->goal)
{
if ((r > 1) && (glob->st[r-2] >= glob->st[r])
&& (glob->st[r-1] == glob->st[r]))
{
queueprob(r-1);
qprob = TRUE;
}
if (r < glob->rows && glob->st[r+1] == glob->st[r]
&& glob->st[r+1] <= glob->st[r+2])
{
queueprob(r+1);
qprob = TRUE;
}
if (glob->st[r-1] == glob->st[r] &&
glob->st[r] == glob->st[r+1])
{
queueprob(r);
qprob = TRUE;
}
}
if (qprob)
return(1); /* new problem */
else
return(0); /* no new problem */
}
int getprob(v)
int *v;
{
int rc = 1;
int *p = (int *) v;
if (glob->pqbeg != glob->pqend)
{
*p = glob->pq[glob->pqbeg];
glob->pqbeg = (glob->pqbeg+1) % (ROWS + 1);
rc = 0;
}
return(rc);
}
P4VOID reset()
{
}
work(who) /* main routine for all processes */
char who;
{
int r,rc,i;
p4_barrier(&(glob->BA),glob->nproc);
rc = p4_askfor(&(glob->MO),glob->nproc,getprob,(P4VOID *)&r,reset);
while (rc == 0) {
if ((glob->st[r] % 2) == 0)
compute(glob->a,glob->b,r,glob->columns);
else
compute(glob->b,glob->a,r,glob->columns);
p4_update(&(glob->MO),putprob,(P4VOID *) r);
/* postprob(r); */
rc = p4_askfor(&(glob->MO),glob->nproc,getprob,(P4VOID *)&r,reset);
}
}
printgrid(m,r,c)
double m[ROWS+2][COLUMNS+2];
int r,c;
{
int i,j;
for (i = 0; i < (r+2); i++)
for (j = 0; j < (c+2); j++)
printf("%3d %3d %10.5f\n",i,j,m[i][j]);
}
double avggrid(m,r,c)
double m[ROWS+2][COLUMNS+2];
int r,c;
{
int i,j;
double avg = 0;
for (i = 0; i < (r+2); i++)
for (j = 0; j < (c+2); j++)
avg += m[i][j];
return(avg/((r+2)*(c+2)));
}
double avgbnd(m,r,c)
double m[ROWS+2][COLUMNS+2];
int r,c;
{
int i,j;
double avg = 0;
for (i = 0; i < (r+2); i++)
avg += m[i][0];
for (i = 0; i < (r+2); i++)
avg += m[i][c+1];
for (i = 1; i < (c+1); i++)
avg += m[0][i];
for (i = 1; i < (c+1); i++)
avg += m[r+1][i];
return(avg/(2*(c+2) + 2*(r+2) - 4)); /* average over boundary */
}