main()
{
int rowsize, /* number of bytes in each row */
iterno, /* current iteration number */
i,
j; /* loop indices */
double resid, /* residual */
residtmp, /* temp */
residglob, /* global residual */
Atmp, /* temp */
Amax; /* value corresponding residglob */
FILE *fd; /* file descriptor */
char host[128]; /* host name */
long t0, t1; /* start and end elapsed time */
/*
* initialize
*
*/
gethostname(host, sizeof(host));
t0 = time ((long*)0);
rdim = DIM;
rowsize = sizeof(double) * (DIM + 2);
inita(); /* guess initial values for A and set B.C. */
/*
* This is the main iteration loop for the Gauss-Seidal method. Refinement
* is done in successive iterations till either the global residual is
* less than desired or MAXITER is reached.
*
*/
Amax = 0.0;
for (iterno= 1; iterno <= MAXITER; iterno++)
{
resid = 0.0;
/*
* Refine the values in A, these two loops consume most of
* the computational time.
*/
for (i = 1; i <= rdim; i++)
for (j = 1; j <= DIM; j++)
{
Atmp = A[i][j];
A[i][j] = 0.25 * (A[i+1][j] + A[i-1][j] +
A[i][j+1] + A[i][j-1]);
residtmp = fabs(A[i][j] - Atmp);
if (residtmp > resid)
{
resid = residtmp;
Amax = Atmp;
}
}
if (Amax == 0.0) /* set global residual */
residglob = 1.0 + EPS;
else
residglob = fabs( resid/Amax );
if (DEBUG && iterno % 100 == 0)
printf ("\nsequential(%d) iterations done\n",iterno);
if ( residglob < EPS) /* termination of iterations */
{
break;
}
}
t1 = time((long *)0) - t0;
/*
* Output the solution
*
*/
fd = fopen("seq_time.dat", "a");
if (t1 > 0)
{
fprintf(fd, "\n (%s) Elapsed time = %d seconds. n: (%d)\n",
host, t1, DIM);
fprintf(fd, " MFLOPS: (%f) Iterations: (%d) Precision (%f)\n",
(float)(DIM)*(DIM) * iterno * 5.0/(t1)/1000000.0,
iterno, residglob);
}
else fprintf(fd, " (%s) Zero second recorded. n: (%d).\n",
host, DIM);
if (iterno >= MAXITER)
{
printf ("iterno: (%d), Precision: (%f), time: (%d sec), n:(%d)\n",
iterno, residglob, t1, DIM);
printf("\n \n WARNING: Maximum iterations reached \n");
printf("%s\n%s\n%s\n\n",
" Try increasing MAXITER if the current Precision,",
" i.e. maximum relative change at any gridblock, is",
" to be further improved ");
}
if (LOG) /* to get output profile */
{
fprintf(fd,"\n");
for (i=0; i<DIM+2; i++)
{
for (j=0; j<DIM+2; j++)
{
fprintf(fd, "%8.1f, ",A[i][j]);
}
fprintf(fd,"\n");
}
fprintf (fd, "\n%s\n\n",
"===============================");
}
printf ("iterno: (%d), residglob: (%f), t1: (%d), n:(%d)\n",
iterno, residglob, t1, DIM);
fclose(fd);
return 0;
}
static void
cecrdr(void *vp)
{
Proc *up = externup();
Block *bp;
Conn *cp;
If *ifc;
Pkt *p;
ifc = vp;
if(waserror())
goto exit;
discover(ifc, 0);
for(;;){
bp = ifc->d->bread(ifc->dc, 1514, 0); // do we care about making the MTU non magic?
if(bp == nil)
nexterror();
p = (Pkt *)bp->rp;
if(p->etype[0] != 0xbc || p->etype[1] != 0xbc){
freeb(bp);
continue;
}
trace(bp);
cp = findconn(p->src, p->conn);
if(cp == nil){
cecprint("cec: out of connection structures\n");
freeb(bp);
continue;
}
if (waserror()){
freeb(bp);
qunlock(cp);
continue;
}
switch(p->type){
case Tinita:
if(cp->bp){
cecprint("cec: reset with bp!? ask quanstro\n");
freeb(cp->bp);
cp->bp = 0;
}
inita(cp, ifc, p);
break;
case Tinitb:
cecprint("cec: unexpected initb\n");
break;
case Tinitc:
if(cp->state == Cinitb){
ack(cp);
if(cp->passwd[0]){
cp->state = Clogin;
conputs(cp, "password: "******"cec: unexpected offer\n"); from ourselves.
break;
case Treset:
if(cp->bp)
freeb(cp->bp);
cp->bp = 0;
cp->state = Cunused;
break;
default:
cecprint("bad cec type: %d\n", p->type);
break;
}
nexterror();
}
exit:
for(cp = conn; cp < conn+nelem(conn); cp++)
if(cp->ifc == ifc){
if(cp->bp)
freeb(cp->bp);
memset(cp, 0, sizeof *cp);
break;
}
memset(ifc, 0, sizeof *ifc);
pexit("cec exiting", 1);
}
