Prefer pause mode on pondering engine over 'easy'

[xboard.git] / backend.c

diff --git a/backend.c b/backend.c
index 614f725..d78319a 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -224,6 +224,7 @@ FILE *WriteTourneyFile P((char *results, FILE *f));
 void DisplayTwoMachinesTitle P(());
 static void ExcludeClick P((int index));
 void ToggleSecond P((void));
+void PauseEngine P((ChessProgramState *cps));
 
 #ifdef WIN32
        extern void ConsoleCreate();
@@ -8111,9 +8112,13 @@ FakeBookMove: // [HGM] book: we jump here to simulate machine moves after book h
            if(appData.debugMode) fprintf(debugFP, "pause %s engine after move\n", cps->which);
            safeStrCpy(stashedInputMove, message, MSG_SIZ);
            stalledEngine = cps;
-           if(appData.ponderNextMove) { // bring both engines out of ponder
-               SendToProgram("easy\n", &first);
-               if(gameMode == TwoMachinesPlay) SendToProgram("easy\n", &second);
+           if(appData.ponderNextMove) { // bring opponent out of ponder
+               if(gameMode == TwoMachinesPlay) {
+                   if(cps->other->pause)
+                       PauseEngine(cps->other);
+                   else
+                       SendToProgram("easy\n", cps->other);
+               }
            }
            StopClocks();
            return;
@@ -13402,7 +13407,7 @@ PauseEvent ()
        if(stalledEngine) { // [HGM] pause: resume game by releasing withheld move
            StartClocks();
            if(gameMode == TwoMachinesPlay) { // we might have to make the opponent resume pondering
-               if(stalledEngine->other->pause) UnPauseEngine(stalledEngine->other);
+               if(stalledEngine->other->pause == 2) UnPauseEngine(stalledEngine->other);
                else if(appData.ponderNextMove) SendToProgram("hard\n", stalledEngine->other);
            }
            if(appData.ponderNextMove) SendToProgram("hard\n", stalledEngine);
@@ -13468,16 +13473,16 @@ PauseEvent ()
                    else
                        SendToProgram("easy\n", onMove->other);
                    StopClocks();
-               }
+               } else if(appData.ponderNextMove) SendToProgram("easy\n", onMove); // pre-emptively bring out of ponder
            } else if(gameMode == (WhiteOnMove(forwardMostMove) ? MachinePlaysWhite : MachinePlaysBlack)) { // engine on move
                if(first.pause) {
                    PauseEngine(&first);
                    StopClocks();
-               }
+               } else if(appData.ponderNextMove) SendToProgram("easy\n", &first); // pre-emptively bring out of ponder
            } else { // human on move, pause pondering by either method
                if(first.pause) 
                    PauseEngine(&first);
-               else
+               else if(appData.ponderNextMove) 
                    SendToProgram("easy\n", &first);
                StopClocks();
            }