BOOL FPrPonderHit(void * pv, char * szMove, unsigned long tmUs,
unsigned long tmThem)
{
PCON pcon = pv;
if (pcon->smode != smodePONDER)
return fFALSE;
if (strcmp(pcon->aszPonder, szMove))
return fFALSE;
pcon->smode = smodeTHINK;
pcon->ss.tmUs = tmUs;
pcon->ss.tmThem = tmThem;
VSetTime(pcon);
return fTRUE;
}
void VThink(PCON pcon, TM tmUs, TM tmThem)
{
Assert(pcon->smode == smodeIDLE);
//VPrSendComment("entering VThink\n");
if (pcon->fLowPriority)
VLowPriority();
if( uciHash.has_changed() )
FInitHashe(pcon);
if( uciBookName.has_changed() )
book_open( uciBookName.get_string() );
if( uciUseEGBB.has_changed() || uciEGBBDir.has_changed() )
prepareEGBB();
//
// Set up time-out, and remind myself that I'm not dead.
//
pcon->ss.tmUs = tmUs;
pcon->ss.tmThem = tmThem;
pcon->fAbort = false;
pcon->smode = (tmUs == tmANALYZE) ? smodeANALYZE : smodeTHINK;
//
// This loop is going to execute at least once. It might execute for the
// whole game, if the program continuously ponders correctly.
//
char aszMove[32];
char aszPonder[32];
aszMove[0] = aszPonder[0] = '\0';
for (;;) {
char aszSanHint[32];
SAN sanHint;
CM cm;
bool f;
//VPrSendComment("for (;;) mode=%d\n", pcon->smode);
stats.raz();
razKillers();
History.raz();
CounterMoves.raz();
initMVVLVA( pcon );
pcon->fTimeout = false; // I'm not timed out yet.
pcon->ss.tmStart = TmNow(); // Record when I started.
if (pcon->smode == // If I'm pondering, I don't set the
smodeTHINK) // time control stuff. This will be
VSetTime(pcon); // handled at the point it's clear
// that I picked the correct move.
bool keepPV = false;
if (pcon->smode ==smodeTHINK) {
// printf("# mode is THINK\n");
if( pcon->gc.argcm > 0 ) {
CM lastMove = pcon->gc.argcm[pcon->gc.ccm - 1];
char asz[16];
CmToSz(&lastMove, asz);
if( lastMove == lastPV[2] ) {
for(int i = 0; i < csteMAX; i++)
lastPV[i] = lastPV[i+2];
keepPV = true;
}
}
}
PSTE pste = &pcon->argste[0];
pste->ccmPv = 0;
if( !keepPV ) {
// Clear the PV
VSetPv(pcon);
}
// VSetRepHash(pcon); // Pump game history into rep hash.
if (pcon->smode == smodeTHINK)
VDrawCheck(pcon); // Try to claim appropriate 50-move
// and 3x rep draws before examining
// moves.
//
// During the first 20 moves of the game I will try to find a book
// move. If I find one I will play it.
//
if ((pcon->smode == smodeTHINK) && (uciOwnBook.get_check()) &&
(pcon->gc.ccm < 40) && (book_find_move(pcon, &cm, true))) {
char asz[16];
CmToSz(&cm, asz); // Make book move.
bool f = FAdvance(pcon, asz);
Assert(f);
VPrSendMove(asz, "");// I am not going to bother checking for draws
// and mates that occur while in book. If by
// weird chance one of these happens, if
// we're hooked up to the chess server, the
// server might call it.
break;
}
// Increment sequence number. The transposition hash system will
// overwrite nodes from old searches, and this is how it knows that
// this is a new search, rather than just more of the old one.
//
VIncrementHashSeq();
//
// Search the position via iterative deepening.
//
pcon->ss.nodes = 0; // Global node counter.
pcon->ss.nodesNext = 2000; // Time (in nodes) of next callback to
// interface.
if( pcon->tc.nodes )
pcon->ss.nodesNext = pcon->tc.nodes;
pcon->ss.tbhits = 0;
pste->evaluated = false;
int staticVal = ValEval(pcon, pste, -20000, 20000);
pste->plyRem = 0;
pcon->ss.plyDepth = 0 + 1;
pcon->ss.lastVal = staticVal;
int oldVal = pcon->ss.lastVal;
// pcon->ss.tmExtend = false;
pcon->ss.easyMove = false;
// pcon->ss.dontStop = false;
pcon->ss.dontStopPrev = false;
pcon->ss.canStop = false;
pcon->ss.currBestMove = CM(0,0);
int prevDepthVal = valMIN;
int val = 0;
int Alpha = valMIN; // Initial window is wide open.
int Beta = valMAX;
for (int i = 0; i < plyMAX; i++) {
// TODO : re enable aspiration window !
pcon->ss.plyMaxDepth = 0;
pste->plyRem = i;
pcon->ss.plyDepth = i + 1;
pcon->ss.failed = false;
pcon->ss.scoreDropped = false;
pcon->ss.rootHasChanged = false;
VPrSendUciDepth( pcon->ss );
val = ValSearchRoot(pcon, pste, Alpha, Beta);
if( pcon->ss.lastVal > oldVal )
oldVal = pcon->ss.lastVal;
else
oldVal = (pcon->ss.lastVal + oldVal)/2;
if( val > pcon->ss.lastVal || (pcon->ss.plyDepth <= 3))
pcon->ss.lastVal = val;
else
pcon->ss.lastVal = (pcon->ss.lastVal + val)/2;
// pcon->ss.lastVal = val;
/* if( pcon->ss.dontStopPrev ) {
printf("# dontStopPrev is set, delta = %d \n", val - oldVal);
if( val - oldVal >= -35 ) {
printf("# reseting dontStopPrev to false\n");
pcon->ss.dontStopPrev = false;
}
}*/
// pcon->ss.dontStop = pcon->ss.scoreDropped;
// pcon->ss.canStop = (pcon->ss.plyDepth >=5) &&
// !pcon->ss.scoreDropped && !pcon->ss.dontStopPrev; // && !pcon->ss.rootHasChanged;
pcon->ss.canStop = (pcon->ss.plyDepth >=1) &&
!pcon->ss.scoreDropped;// && !pcon->ss.dontStopPrev; // && !pcon->ss.rootHasChanged;
printf("# scoreDropped=%d rootChanged=%d stopPrev=%d => canStop=%d\n",
pcon->ss.scoreDropped, pcon->ss.rootHasChanged, pcon->ss.dontStopPrev, pcon->ss.canStop);
// pcon->ss.dontStopPrev = pcon->ss.dontStop;
pcon->ss.dontStopPrev = pcon->ss.scoreDropped;
// Initialize the PV with the result of the previous search
VSetPv(pcon);
if (pcon->fAbort || pcon->fTimeout)
break;
//
// This checks for a result outside the window, and if it finds
// one it re-searches with the window wide open.
//
if ((val <= Alpha) || (val >= Beta)) {
if (val <= Alpha) // Record a fail-low (fail-high is
// handled inside "ValSearch").
//
// This function needs the root moves generated, and they
// are, because "ValSearch" does it.
//
VDumpPv(pcon, pcon->ss.plyDepth, val, prsaFAIL_LOW);
val = ValSearchRoot(pcon, pste, valMIN, valMAX);
// Initialize the PV with the result of the previous search
VSetPv(pcon);
if (pcon->fAbort)
break;
if (pcon->fTimeout)
break;
}
// VIncrementHashSeq();
pcon->ss.prsa = prsaNORMAL;
pcon->ss.val = val;
//
// Mated now or this move mates, drop out of here.
//
if ((pcon->ss.val == valMATE - 1) || (pcon->ss.val == -valMATE))
break;
// found a mate in n, no need to iterate
if( (val == prevDepthVal) && (val > /*50*100*/(valMATE - 500) ) && (pcon->smode != smodeANALYZE) )
break;
prevDepthVal = val;
// stop thinking if there is only one move, no need to let the other guy
// think longer
if( pcon->ss.ccmLegalMoves == 1 ) {
// we can still look a bit so we have a PV set for the next move
if( i >= 5 && (pcon->smode == smodeTHINK))
break;
}
if( (pcon->smode == smodeTHINK) ) {
int usedTime = TmNow() - pcon->ss.tmStart;
int remaingingTime = pcon->ss.tmEnd - TmNow();
if( pcon->ss.canStop && !pcon->ss.rootHasChanged && (usedTime > remaingingTime) ) {
VPrSendComment("time : used=%d remaining =%d\n", usedTime, remaingingTime);
break;
}
}
#if 0
if( (pcon->smode == smodeTHINK) ) {
int usedTime = TmNow() - pcon->ss.tmStart;
int remaingingTime = pcon->ss.tmEnd + pcon->ss.tmExtra / 9 - TmNow();
const int bf = int(1.9f * 32); // kind of branching factor
if( (!pcon->ss.failed) && (usedTime * bf) / 32 > remaingingTime ) {
VPrSendComment("time : used=%d remaining =%d\n", usedTime, remaingingTime);
break;
}
}
#endif
//
// Depth-restricted search. Check for "timeout", meaning target
// depth met.
//
if (((pcon->smode == smodeTHINK) || (pcon->smode == smodePONDER))
&& (pcon->tc.plyDepth > 0) &&
(pcon->ss.plyDepth >= pcon->tc.plyDepth))
break;
//
// Set up for next iteration, which will use a window centered
// around the current position value.
//
// Alpha = val - 50;
// Beta = val + 50;
}
// If abort or doing pondering, I'm done, because I don't need to
// make any moves or set up the next search.
//
// NOTE: None of the stuff below happens in analysis mode, because
// the next line exits the routine! This means that results won't
// be posted (draws, mates, etc.) if the game is in analysis mode,
// which seems to be the right thing to do according to Tim Mann,
// circa 26-Apr-2001 on the Yahoo chess engines mailing list.
//
#ifdef _DEBUG
stats.report();
#endif
//
// If there is a move in the first element of the PV, I can make it.
// I don't make it now, because I want to look at the second element
// of the PV for a pondering move, and if I execute the first move,
// it will destroy the PV.
//
aszMove[0] = aszPonder[0] = '\0';
if (pste->ccmPv >= 1)
CmToSz(&pste->argcmPv[0], aszMove);
CM cmHint;
if ((pste->ccmPv >= 2)) {
CmToSz(&pste->argcmPv[1], aszPonder);
cmHint = pste->argcmPv[1];
}
// this line was moved down for uci support
// TODO : check this
if ((pcon->fAbort) || (pcon->smode != smodeTHINK))
break;
// As of this point, I have move to make in "aszMove", move to ponder
// in "aszPonder". If I can't move, or I can't ponder, these strings
// are nulled out.
//
// Check to see if I'm mated or stalemated, which will be the case
// if I can't move.
//
if (aszMove[0] == '\0') {
if ((!pcon->fTimeout) && (pcon->ss.val == -valMATE)) {
VMates(pste->side ^ 1);
break;
}
VStalemate(pste->side);
break;
}
//VPrSendComment("advancing my move=%s\n", aszMove);
f = FAdvance(pcon, aszMove);
Assert(f);
//
// Deal with draw offers right before the move is sent to the
// interface. This boolean is set when the opponent offers a draw.
// It is cleared when the interface tells us to set up a new
// position, and when the engine makes a move.
//
// If this boolean is not cleared at the appropriate time, it's not
// critically bad, because all that will happen is that the program
// will offer an unsolicited draw in a position it thinks is drawn.
//
// The engine will execute its planned move after trying to agree to
// the draw, in case something goes wrong with the draw offer.
//
// If the interface can't handle this, there could be problems.
//
// This code is before the resignation code in order to catch the
// one-in-a-million case where the opponent offers a draw before the
// engine can resign.
//
if (pcon->fDrawOffered) {
if (FAcceptDraw(pcon, pste))
VPrOfferDraw();
pcon->fDrawOffered = false;
}
// Check to see if I should resign, and do so if necessary. The move
// the engine is planning to make is not executed in this case, in
// order to avoid the unattractive <move made> <resigns> sequence.
//
// If the interface doesn't listen to the resignation, the program
// simply won't move.
//
else if (FCheckResign(pcon, pste))
break;
// Inform the interface that we have a move.
//
if( ! pcon->isUCI )
VPrSendMove(aszMove, aszPonder);
//
// The score from the last search might indicate that this is mate.
//
if ((!pcon->fTimeout) && (val == valMATE - 1)) {
VMates(pste->side ^ 1); // This is backwards because we already
break; // moved on the internal board.
}
// Check for 50-move or 3x repetition draws.
//
VDrawCheck(pcon);
//
// Check to see if I stalemated my opponent, and report the result as
// appropriate.
//
if (FStalemated(pcon))
VStalemate(pste->side ^ 1);
//
// If the PV contained at least two moves, and the "fPonder" boolean
// is set, the second one is sitting in "aszPonder".
//
// If there is no move, we're done, and we're going to drop out of
// the bottom of this routine and leave.
//
// If there was a move, I'm going to set our state to "smodePONDER",
// remember the move that we are pondering on, execute the move on
// the board, and loop around to the top of this think loop and start
// thinking again.
//
// Later, if the the interface passes in the move that we are
// pondering on, the state info will be dummied up so the program
// thinks it's doing a normal search. If the wrong move is passed in
// (the opponent made a move we didn't expect), we'll abort the
// search, undo the last move, exit this routine, and be called again
// and told to think.
//
// So we get into this routine when we're told to think about
// something, and we stay in here until we fail to predict the
// opponent's move.
//
if (aszPonder[0] == '\0' || !pcon->fPonder )
break;
//
// Get the algebraic so I can send a hint move. The Winboard
// interface will stick this at the beginning of the PV it displays
// while we are pondering.
//
bGenMoves(pcon, pcon->argste);
CmToSan(pcon, pcon->argste, &cmHint, &sanHint);
SanToSz(&sanHint, aszSanHint);
strcpy(pcon->aszPonder, aszPonder);
// VPrSendComment("potential ponder move(2)=%s\n", aszSanHint);
//
// Execute the move. I'm now one move ahead of the game, which is
// tricky. After that, send the hint move.
//
// VPrSendComment("ok let's advance for the ponder move %s\n", aszPonder);
f = FAdvance(pcon, aszPonder);
Assert(f);
if (pcon->fPost)
VPrSendHint(aszSanHint);
VPrSendComment("switching to ponder mode, previous mode was=%d\n", pcon->smode);
pcon->smode = smodePONDER;
}
// Inform the interface that we have a move.
//
if( pcon->isUCI ) {
VPrSendUciNodeCount(true, pcon->ss );
VPrSendMove(aszMove, aszPonder);
}
// If I broke out, and I'm in ponder mode, back up the search and pretend
// that I never pondered. I could do some sneaky stuff having to do with
// remembering the move that would have been made if the pondered search
// had been converted into a normal search soon enough, but this would be
// annoying to do and it's kind of rare and pointless.
//
stats.report2();
//VPrSendComment("end of VThink mode is %d\n", pcon->smode );
if (pcon->smode == smodePONDER)
VUndoMove(pcon);
pcon->smode = smodeIDLE;
}