Implement 'pause' command

The CECP 'pause' an 'resume' commands are implemente, and announced in
the corresponding feature. Commands in paused mode are ignored, except
'quit'. The ReadClock() function has been adapted to allow initialization
of the startTime with an offset, to give the paused time back to the clock.
For this the nodeCount (which naturally stops incrementing during pauses)
has to be reset outside ReadClock again.

diff --git a/dropper.c b/dropper.c
index 6d8ae23..a21fc21 100644 (file)
--- a/dropper.c
+++ b/dropper.c
@@ -1763,11 +1763,11 @@ int contemptFactor; // likewise
 
 int
 ReadClock (int start, int print)
-{
+{ // 'print' indicates we want true time (i.e. not nodes-derived), or provides offset while resetting clock
   static int startTime; int t;
   if(nodeRate > 0 && !start && !print) return nodeCount*1000LL/nodeRate;
   t = (nodeRate >= 0 ? (int)(CPUtime()) : GetTickCount());
-  if(start) startTime = t, nodeCount = 0;
+  if(start) startTime = t - print;
   return t - startTime; // msec
 }
 
@@ -1849,7 +1849,7 @@ ReadLine ()
 int
 DoCommand (int searching)
 {
-  char command[80];
+  char command[80]; int paused = 0;
 
   while(1) { // usually we break out of this loop after treating one command
 
@@ -1861,6 +1861,9 @@ printf("# command: %s\n", inBuf);
 
     // recognize and execute 'easy' commands, i.e those that can be executed during search
     if(!strcmp(command, "quit"))    { exit(0); }  // exit immediately
+    if(!strcmp(command, "resume"))  { ReadClock(1, paused); return 0; }     // continue searching
+    if(paused) continue; // during pause, keep reading, ignoring everything except quit and resume
+    if(!strcmp(command, "pause"))   { paused = ReadClock(0, 1); continue; } // remember (true) time already used
     if(!strcmp(command, "otim"))    { continue; } // move will follow immediately, wait for it
     if(!strcmp(command, "time"))    { sscanf(inBuf+4, "%d", &timeLeft); continue; }
     if(!strcmp(command, "easy"))    { ponder = OFF; return 0; }
@@ -1897,7 +1900,7 @@ printf("# command: %s\n", inBuf);
     }
     if(!strcmp(command, "protover")){
       printf("feature ping=1 setboard=1 colors=0 usermove=1 memory=1 debug=1 reuse=0 sigint=0 sigterm=0 "
-            "exclude=1 nps=1 myname=\"CrazyWa " VERSION "\"\n");
+            "exclude=1 nps=1 pause=1 myname=\"CrazyWa " VERSION "\"\n");
       printf("feature variants=\"crazyhouse,shogi,minishogi,judkinshogi,torishogi,euroshogi,crazywa,kyotoshogi,"
                                "5x5+4_shogi,5x5+5_shogi,6x6+6_shogi,7x7+6_shogi,11x17+16_chu\"\n");
       printf("feature option=\"Resign -check 0\"\n");           // example of an engine-defined option
@@ -1969,7 +1972,7 @@ main ()
 
     if(stm == engineSide) {         // if it is the engine's turn to move, set it thinking, and let it move
 {int i;for(i=0; i<=hashMask+3; i++) /*if(hashTable[i].score != hashTable[i].lim)*/ hashTable[i].lock = 0;}
-      forceMove = undoInfo.move = abortFlag = 0; ReadClock(1, 0);
+      nodeCount = forceMove = undoInfo.move = abortFlag = 0; ReadClock(1, 0);
       for(i=0;i<1<<16;i++) history[i] = 0; //>>= 1;
       for(i=0;i<1<<17;i++) mateKillers[i] = 0;
       score = Search(stm^COLOR, -INF, INF, &undoInfo, maxDepth, 0, maxDepth);
@@ -1988,7 +1991,7 @@ main ()
 
     // now it is not our turn (anymore)
     if(engineSide == ANALYZE) {       // in analysis, we always ponder the position
-        forceMove = undoInfo.move = abortFlag = 0; ReadClock(1, 0);
+        nodeCount = forceMove = undoInfo.move = abortFlag = 0; ReadClock(1, 0);
         Search(stm^COLOR, -INF, INF, &undoInfo, maxDepth, 0, maxDepth);
     }
 #if 0