Fix concurrency in Swiss tourneys
[xboard.git] / backend.c
index 6238eeb..6243fa3 100644 (file)
--- a/backend.c
+++ b/backend.c
@@ -9779,22 +9779,7 @@ NextTourneyGame(int nr, int *swapColors)
     InitTimeControls(); // TC might be altered from tourney file
 
     nPlayers = CountPlayers(appData.participants); // count participants
-    if(appData.tourneyType < 0 && appData.pairingEngine[0]) {
-       if(nr>=0 && !pairingReceived) {
-           char buf[1<<16];
-           if(pairing.pr == NoProc) StartChessProgram(&pairing);
-           snprintf(buf, 1<<16, "results %d %s\n", nPlayers, appData.results);
-           SendToProgram(buf, &pairing);
-           snprintf(buf, 1<<16, "pairing %d\n", nr+1);
-           SendToProgram(buf, &pairing);
-           return 0; // wait for pairing engine to answer (which causes NextTourneyGame to be called again...
-       }
-       pairingReceived = 0;                              // ... so we continue here 
-       syncInterval = nPlayers/2; *swapColors = 0;
-       appData.matchGames = appData.tourneyCycles * syncInterval - 1;
-       whitePlayer = savedWhitePlayer-1; blackPlayer = savedBlackPlayer-1;
-       matchGame = 1; roundNr = nr / syncInterval + 1;
-    } else
+    if(appData.tourneyType < 0) syncInterval = nPlayers/2; else
     *swapColors = Pairing(nr<0 ? 0 : nr, nPlayers, &whitePlayer, &blackPlayer, &syncInterval);
 
     if(syncInterval) {
@@ -9809,6 +9794,29 @@ NextTourneyGame(int nr, int *swapColors)
        waitingForGame = FALSE;
     }
 
+    if(appData.tourneyType < 0) {
+       if(nr>=0 && !pairingReceived) {
+           char buf[1<<16];
+           if(pairing.pr == NoProc) {
+               if(!appData.pairingEngine[0]) {
+                   DisplayFatalError(_("No pairing engine specified"), 0, 1);
+                   return 0;
+               }
+               StartChessProgram(&pairing); // starts the pairing engine
+           }
+           snprintf(buf, 1<<16, "results %d %s\n", nPlayers, appData.results);
+           SendToProgram(buf, &pairing);
+           snprintf(buf, 1<<16, "pairing %d\n", nr+1);
+           SendToProgram(buf, &pairing);
+           return 0; // wait for pairing engine to answer (which causes NextTourneyGame to be called again...
+       }
+       pairingReceived = 0;                              // ... so we continue here 
+       *swapColors = 0;
+       appData.matchGames = appData.tourneyCycles * syncInterval - 1;
+       whitePlayer = savedWhitePlayer-1; blackPlayer = savedBlackPlayer-1;
+       matchGame = 1; roundNr = nr / syncInterval + 1;
+    }
+
     if(first.pr != NoProc) return 1; // engines already loaded
 
     // redefine engines, engine dir, etc.