/*
* return the number of the highest-numbered block actually written, plus 1.
* 0 indicates an error.
*/
static Devsize
writtensize(Device *worm)
{
Devsize lim = devsize(worm);
Iobuf *p;
print("devsize(%Z) = %lld\n", worm, (Wideoff)lim);
if (!blockok(worm, 0) || !blockok(worm, lim-1))
return 0;
delay(5*1000);
if (userabort("sanity checks"))
return 0;
/* find worm's last valid block in case "worm" is an (f)worm */
while (lim > 0) {
if (userabort("sizing")) {
lim = 0; /* you lose */
break;
}
--lim;
p = getbuf(worm, lim, Brd);
if (p != 0) { /* actually read one okay? */
putbuf(p);
break;
}
}
print("limit(%Z) = %lld\n", worm, (Wideoff)lim);
if (lim <= 0)
return 0;
return lim + 1;
}
/* copy device from src to dest */
static int
dodevcopy(void)
{
Device *from, *to;
Iobuf *p;
Off a;
Devsize lim, tosize;
/*
* convert config strings into Devices.
*/
from = iconfig(src);
if(f.error || from == nil) {
print("bad src device %s\n", src);
return -1;
}
to = iconfig(dest);
if(f.error || to == nil) {
print("bad dest device %s\n", dest);
return -1;
}
/*
* initialise devices, size them, more sanity checking.
*/
devinit(from);
lim = devsize(from);
if(lim == 0)
panic("no blocks to copy on %Z", from);
devinit(to);
tosize = devsize(to);
if(tosize == 0)
panic("no blocks to copy on %Z", to);
/* use smaller of the device sizes */
if (tosize < lim)
lim = tosize;
print("copy %Z to %Z in 8 seconds\n", from, to);
delay(8000);
if (userabort("preparing to copy"))
return -1;
print("copying dev: %lld blocks from %Z to %Z\n", (Wideoff)lim,
from, to);
/*
* Copy all blocks, a block at a time.
*/
for (a = 0; a < lim; a++) {
if (userabort("copy"))
break;
p = getbuf(from, a, Brd);
/*
* if from is a real WORM device, we'll get errors trying to
* read unwritten blocks, but the unwritten blocks need not
* be contiguous.
*/
if (p == 0) {
print("%lld not written yet; can't read\n", (Wideoff)a);
continue;
}
if (to != 0 && devwrite(to, p->addr, p->iobuf) != 0) {
print("out block %lld: write error; bailing",
(Wideoff)a);
break;
}
putbuf(p);
if(a % 20000 == 0)
print("block %lld %T\n", (Wideoff)a, time(nil));
}
/*
* wrap up: sync target
*/
print("copied %lld blocks from %Z to %Z\n", (Wideoff)a, from, to);
sync("devcopy");
return 0;
}
/* copy worm fs from "main"'s inner worm to "output" */
static void
dowormcopy(void)
{
Filsys *f1, *f2;
Device *fdev, *from, *to = nil;
Iobuf *p;
Off a;
Devsize lim;
/*
* convert file system names into Filsyss and Devices.
*/
f1 = fsstr("main");
if(f1 == nil)
panic("main file system missing");
fdev = f1->dev;
from = wormof(fdev); /* fake worm special */
if (from->type != Devfworm && from->type != Devcw) {
print("main file system is not a worm; copyworm may not do what you want!\n");
print("waiting for 20 seconds...\n");
delay(20000);
}
f2 = fsstr("output");
if(f2 == nil) {
print("no output file system - check only\n\n");
print("reading worm from %Z (worm %Z)\n", fdev, from);
} else {
to = f2->dev;
print("\ncopying worm from %Z (worm %Z) to %Z, starting in 8 seconds\n",
fdev, from, to);
delay(8000);
}
if (userabort("preparing to copy"))
return;
/*
* initialise devices, size them, more sanity checking.
*/
devinit(from);
if (0 && fdev != from) {
devinit(fdev);
print("debugging, sizing %Z first\n", fdev);
writtensize(fdev);
}
lim = writtensize(from);
if(lim == 0)
panic("no blocks to copy on %Z", from);
if (to) {
print("reaming %Z in 8 seconds\n", to);
delay(8000);
if (userabort("preparing to ream & copy"))
return;
devream(to, 0);
devinit(to);
print("copying worm: %lld blocks from %Z to %Z\n",
(Wideoff)lim, from, to);
}
/* can't read to's blocks in case to is a real WORM device */
/*
* Copy written fs blocks, a block at a time (or just read
* if no "output" fs).
*/
for (a = 0; a < lim; a++) {
if (userabort("copy"))
break;
p = getbuf(from, a, Brd);
/*
* if from is a real WORM device, we'll get errors trying to
* read unwritten blocks, but the unwritten blocks need not
* be contiguous.
*/
if (p == 0) {
print("%lld not written yet; can't read\n", (Wideoff)a);
continue;
}
if (to != 0 && devwrite(to, p->addr, p->iobuf) != 0) {
print("out block %lld: write error; bailing",
(Wideoff)a);
break;
}
putbuf(p);
if(a % 20000 == 0)
print("block %lld %T\n", (Wideoff)a, time(nil));
}
/*
* wrap up: sync target, loop
*/
print("copied %lld blocks from %Z to %Z\n", (Wideoff)a, from, to);
sync("wormcopy");
delay(2000);
print("looping; reset the machine at any time.\n");
for (; ; )
continue; /* await reset */
}
STATIC int primloop(lprec *lp, MYBOOL feasible)
{
int i, j, k, ok = TRUE;
LREAL theta = 0.0;
REAL *prow = NULL, *drow = NULL, *pcol = NULL, prevobj, epsvalue;
MYBOOL primal = TRUE, minit;
MYBOOL pivdynamic, bfpfinal = FALSE;
int oldpivrule, oldpivmode, pivrule, Blandswitches,
colnr, rownr, lastnr, minitcount = 0;
int Rcycle = 0, Ccycle = 0, Ncycle = 0, changedphase = FALSE;
int *nzdrow = NULL, *workINT = NULL;
/* Add sufficent number of artificial variables to make the problem feasible
through the first phase; delete when primal feasibility has been achieved */
lp->Extrap = 0;
#ifdef EnablePrimalPhase1
if(!feasible) {
#ifdef Paranoia
if(!verifyBasis(lp))
report(lp, SEVERE, "primloop: No valid basis for artificial variables\n");
#endif
#if 0
/* First check if we can get away with a single artificial variable */
if(lp->equalities == 0) {
i = (int) feasibilityOffset(lp, !primal);
add_artificial(lp, i);
}
else
#endif
/* Otherwise add as many as is necessary to force basic feasibility */
for(i = 1; i <= lp->rows; i++)
add_artificial(lp, i);
}
if(lp->spx_trace)
report(lp, DETAILED, "Extrap count = %d\n", lp->Extrap);
#endif
if(lp->spx_trace)
report(lp, DETAILED, "Entered primal simplex algorithm with feasibility %s\n",
my_boolstr(feasible));
/* Create work arrays */
#ifdef UseSparseReducedCost
allocINT(lp, &nzdrow, lp->sum + 1, FALSE);
#endif
allocREAL(lp, &prow, lp->sum + 1, TRUE);
allocREAL(lp, &drow, lp->sum + 1, TRUE);
allocREAL(lp, &pcol, lp->rows + 1, TRUE);
/* Refactorize the basis and set status variables */
i = my_if(is_bb_action(lp, ACTION_REBASE), INITSOL_SHIFTZERO, INITSOL_USEZERO);
if(((lp->spx_status == SWITCH_TO_PRIMAL) && !lp->justInverted) ||
(lp->Extrap != 0) ||
is_bb_action(lp, ACTION_REINVERT)) {
simplexPricer(lp, (MYBOOL)!primal);
/* Do basis crashing before refactorization, if specified */
invert(lp, (MYBOOL) i, TRUE);
}
else {
if(is_bb_action(lp, ACTION_RECOMPUTE))
recompute_solution(lp, (MYBOOL) i);
restartPricer(lp, (MYBOOL)!primal);
}
lp->bb_action = ACTION_NONE;
lp->spx_status = RUNNING;
lp->doIterate = FALSE;
minit = ITERATE_MAJORMAJOR;
prevobj = lp->rhs[0];
oldpivmode = lp->piv_strategy;
oldpivrule = get_piv_rule(lp);
pivdynamic = ANTICYCLEBLAND && is_piv_mode(lp, PRICE_ADAPTIVE);
epsvalue = lp->epspivot;
Blandswitches = 0;
rownr = 0;
colnr = 0;
lastnr = 0;
lp->rejectpivot[0] = 0;
if(feasible)
lp->simplex_mode = SIMPLEX_Phase2_PRIMAL;
else
lp->simplex_mode = SIMPLEX_Phase1_PRIMAL;
/* Iterate while we are successful; exit when the model is infeasible/unbounded,
or we must terminate due to numeric instability or user-determined reasons */
while(lp->spx_status == RUNNING) {
if(lp->spx_trace)
if(lastnr > 0)
report(lp, NORMAL, "primloop: Objective at iteration %8d is " RESULTVALUEMASK " (%4d: %4d %s- %4d)\n",
get_total_iter(lp), lp->rhs[0], rownr, lastnr,
my_if(minit == ITERATE_MAJORMAJOR, "<","|"), colnr);
pivrule = get_piv_rule(lp);
if(pivdynamic && ((pivrule != PRICER_FIRSTINDEX) ||
(pivrule != oldpivrule))
#if PrimalPivotStickiness==2
&& (lp->fixedvars == 0)
#elif PrimalPivotStickiness==1
&& feasible
#endif
) {
/* Check if we have a stationary solution */
if((minit == ITERATE_MAJORMAJOR) && !lp->justInverted &&
(fabs(my_reldiff(lp->rhs[0], prevobj)) < epsvalue)) {
Ncycle++;
/* Start to monitor for variable cycling if this is the initial stationarity */
if(Ncycle <= 1) {
Ccycle = colnr;
Rcycle = rownr;
}
/* Check if we should change pivoting strategy due to stationary variable cycling */
else if((pivrule == oldpivrule) && (((MAX_STALLCOUNT > 1) && (Ncycle > MAX_STALLCOUNT)) ||
(Ccycle == rownr) || (Rcycle == colnr))) {
/* First check if we should give up on Bland's rule and try perturbed bound
relaxation instead */
#ifdef EnableStallAntiDegen
if((MAX_BLANDSWITCH >= 0) && (Blandswitches >= MAX_BLANDSWITCH)) {
lp->spx_status = DEGENERATE;
break;
}
#endif
Blandswitches++;
lp->piv_strategy = PRICER_FIRSTINDEX; /* There is no advanced normalization for Bland's rule, restart at end */
Ccycle = 0;
Rcycle = 0;
Ncycle = 0;
if(lp->spx_trace)
report(lp, DETAILED, "primloop: Detected cycling at iteration %d; changed to FIRST INDEX rule!\n",
get_total_iter(lp));
}
}
#if 0
/* Handle cycling or stationary situations by switching to the dual simplex */
else if((pivrule == oldpivrule) && feasible && (lp->simplex_strategy & SIMPLEX_DYNAMIC)) {
lp->spx_status = SWITCH_TO_DUAL;
if(lp->total_iter == 0)
report(lp, NORMAL, "Start dual simplex for finalization at iteration %8d\n",
get_total_iter(lp));
break;
}
#endif
/* Change back to original selection strategy as soon as possible */
else if((minit == ITERATE_MAJORMAJOR) && (pivrule != oldpivrule)) {
lp->piv_strategy = oldpivmode;
restartPricer(lp, AUTOMATIC); /* Pricer restart following Bland's rule */
Ccycle = 0;
Rcycle = 0;
Ncycle = 0;
if(lp->spx_trace)
report(lp, DETAILED, "...returned to original pivot selection rule at iteration %d.\n",
get_total_iter(lp));
}
}
/* Store current LP value for reference at next iteration */
prevobj = lp->rhs[0];
lp->doIterate = FALSE;
lp->doInvert = FALSE;
/* Find best column to enter the basis */
RetryCol:
if(!changedphase) {
i = 0;
do {
if(partial_countBlocks(lp, (MYBOOL) !primal) > 1)
partial_blockStep(lp, (MYBOOL) !primal);
colnr = colprim(lp, (MYBOOL) (minit == ITERATE_MINORRETRY), drow, nzdrow);
i++;
} while ((colnr == 0) && (i < partial_countBlocks(lp, (MYBOOL) !primal)));
#ifdef FinalOptimalErrorLimitation
/* Do additional checking that we have a correct identification of optimality */
if((colnr == 0) && !lp->justInverted) {
lp->doInvert = TRUE;
i = invert(lp, INITSOL_USEZERO, TRUE);
colnr = colprim(lp, FALSE, drow, nzdrow);
}
#endif
}
if(colnr > 0) {
changedphase = FALSE;
fsolve(lp, colnr, pcol, workINT, lp->epsmachine, 1.0, TRUE); /* Solve entering column for Pi */
#ifdef UseRejectionList
if(is_anti_degen(lp, ANTIDEGEN_COLUMNCHECK) && !check_degeneracy(lp, pcol, NULL)) {
if(lp->rejectpivot[0] < DEF_MAXPIVOTRETRY/3) {
i = ++lp->rejectpivot[0];
lp->rejectpivot[i] = colnr;
report(lp, DETAILED, "Entering column %d found to be non-improving due to degeneracy!\n",
colnr);
goto RetryCol;
}
else {
lp->rejectpivot[0] = 0;
report(lp, DETAILED, "Gave up trying to find a strictly improving entering column!\n");
}
}
#endif
/* Find the leaving variable that gives the most stringent bound on the entering variable */
theta = drow[colnr];
rownr = rowprim(lp, colnr, &theta, pcol);
#if 0
report(lp, NORMAL, "Iteration %d: Enter %d, Leave %d\n", lp->current_iter, colnr, rownr);
#endif
/* See if we can do a straight artificial<->slack replacement (when "colnr" is a slack) */
if((lp->Extrap != 0) && (rownr == 0) && (colnr <= lp->rows))
rownr = findAnti_artificial(lp, colnr);
if(rownr > 0) {
lp->rejectpivot[0] = 0;
lp->bfp_prepareupdate(lp, rownr, colnr, pcol);
}
else if(lp->spx_status == UNBOUNDED) {
report(lp, DETAILED, "primloop: The model is primal unbounded.\n");
break;
}
#ifdef UseRejectionList
else if(lp->rejectpivot[0] < DEF_MAXPIVOTRETRY) {
lp->spx_status = RUNNING;
if(lp->justInverted) {
lp->rejectpivot[0]++;
lp->rejectpivot[lp->rejectpivot[0]] = colnr;
report(lp, DETAILED, "...trying to recover via another pivot column!\n");
}
else {
lp->doInvert = TRUE;
invert(lp, INITSOL_USEZERO, TRUE);
}
goto RetryCol;
}
#endif
else {
/* Assume failure if we are still unsuccessful and the model is not unbounded */
if((rownr == 0) && (lp->spx_status == RUNNING)) {
report(lp, IMPORTANT, "primloop: Could not find a leaving variable for entering %d (iteration %d)\n",
colnr, get_total_iter(lp));
lp->spx_status = NUMFAILURE;
}
}
}
#ifdef EnablePrimalPhase1
else if(!feasible || isPhase1(lp)) {
if(feasiblePhase1(lp, epsvalue)) {
lp->spx_status = RUNNING;
if(lp->bb_totalnodes == 0) {
report(lp, NORMAL, "Found feasibility by primal simplex at iteration %8d\n",
get_total_iter(lp));
if((lp->usermessage != NULL) && (lp->msgmask & MSG_LPFEASIBLE))
lp->usermessage(lp, lp->msghandle, MSG_LPFEASIBLE);
}
changedphase = FALSE;
feasible = TRUE;
lp->simplex_mode = SIMPLEX_Phase2_PRIMAL;
/* We can do two things now;
1) delete the rows belonging to those variables, since they are redundant, OR
2) drive out the existing artificial variables via pivoting. */
if(lp->Extrap > 0) {
#ifdef Phase1EliminateRedundant
/* If it is not a MIP model we can try to delete redundant rows */
if((lp->bb_totalnodes == 0) && (MIP_count(lp) == 0)) {
while(lp->Extrap > 0) {
i = lp->rows;
while((i > 0) && (lp->var_basic[i] <= lp->sum-lp->Extrap))
i--;
#ifdef Paranoia
if(i <= 0) {
report(lp, SEVERE, "primloop: Could not find redundant artificial.\n");
break;
}
#endif
/* Obtain column and row indeces */
j = lp->var_basic[i]-lp->rows;
k = get_artificialRow(lp, j);
/* Delete row before column due to basis "compensation logic" */
if(lp->is_basic[k]) {
lp->is_basic[lp->rows+j] = FALSE;
del_constraint(lp, k);
}
else
setBasisVar(lp, i, k);
del_column(lp, j);
lp->Extrap--;
}
lp->basis_valid = TRUE;
}
/* Otherwise we drive out the artificials by elimination pivoting */
else {
eliminate_artificials(lp, prow);
lp->doIterate = FALSE;
}
#else
lp->Extrap = my_flipsign(lp->Extrap);
#endif
}
lp->doInvert = TRUE;
prevobj = lp->infinite;
}
else {
lp->spx_status = INFEASIBLE;
minit = ITERATE_MAJORMAJOR;
if(lp->spx_trace)
report(lp, NORMAL, "Model infeasible by primal simplex at iteration %8d\n",
get_total_iter(lp));
}
}
#endif
/* Pivot row/col and update the inverse */
if(lp->doIterate) {
lastnr = lp->var_basic[rownr];
if(lp->justInverted)
minitcount = 0;
else if(minitcount > MAX_MINITUPDATES) {
recompute_solution(lp, INITSOL_USEZERO);
minitcount = 0;
}
minit = performiteration(lp, rownr, colnr, theta, primal, NULL, NULL,
pcol, NULL);
if(minit != ITERATE_MAJORMAJOR)
minitcount++;
if((lp->spx_status == USERABORT) || (lp->spx_status == TIMEOUT))
break;
else if(minit == ITERATE_MINORMAJOR)
continue;
#ifdef UsePrimalReducedCostUpdate
/* Do a fast update of the reduced costs in preparation for the next iteration */
if(minit == ITERATE_MAJORMAJOR)
update_reducedcosts(lp, primal, lastnr, colnr, pcol, drow);
#endif
#ifdef EnablePrimalPhase1
/* Detect if an auxiliary variable has left the basis and delete it; if
the non-basic variable only changed bound (a "minor iteration"), the
basic artificial variable did not leave and there is nothing to do */
if((minit == ITERATE_MAJORMAJOR) && (lastnr > lp->sum - abs(lp->Extrap))) {
#ifdef Paranoia
if(lp->is_basic[lastnr] || !lp->is_basic[colnr])
report(lp, SEVERE, "primloop: Invalid basis indicator for variable %d at iteration %d\n",
lastnr, get_total_iter(lp));
#endif
del_column(lp, lastnr-lp->rows);
if(lp->Extrap > 0)
lp->Extrap--;
else
lp->Extrap++;
if(lp->Extrap == 0) {
colnr = 0;
prevobj = lp->infinite;
changedphase = TRUE;
}
}
#endif
}
if(lp->spx_status == SWITCH_TO_DUAL)
;
else if(!changedphase && lp->bfp_mustrefactorize(lp)) {
i = invert(lp, INITSOL_USEZERO, FALSE);
#ifdef ResetMinitOnReinvert
minit = ITERATE_MAJORMAJOR;
#endif
if((lp->spx_status == USERABORT) || (lp->spx_status == TIMEOUT))
break;
else if(!i) {
lp->spx_status = SINGULAR_BASIS;
break;
}
/* Check whether we are still feasible or not... */
if(!isPrimalFeasible(lp, lp->epspivot)) {
lp->spx_status = LOSTFEAS;
}
}
userabort(lp, -1);
}
if (lp->piv_strategy != oldpivmode)
lp->piv_strategy = oldpivmode;
#ifdef EnablePrimalPhase1
/* Remove any remaining artificial variables (feasible or infeasible model) */
lp->Extrap = abs(lp->Extrap);
if(lp->Extrap > 0) {
clear_artificials(lp);
if(lp->spx_status != OPTIMAL)
restore_basis(lp);
i = invert(lp, INITSOL_USEZERO, TRUE);
}
#ifdef Paranoia
if(!verifyBasis(lp))
report(lp, SEVERE, "primloop: Invalid basis detected due to internal error\n");
#endif
/* Switch to dual phase 1 simplex for MIP models during B&B phases */
if((lp->bb_totalnodes == 0) && (MIP_count(lp) > 0) &&
((lp->simplex_strategy & SIMPLEX_Phase1_DUAL) == 0)) {
lp->simplex_strategy &= !SIMPLEX_Phase1_PRIMAL;
lp->simplex_strategy += SIMPLEX_Phase1_DUAL;
}
#endif
FREE(nzdrow);
FREE(drow);
FREE(prow);
FREE(pcol);
return(ok);
} /* primloop */
