Further refine SMP code

[stockfish] / src / thread.cpp

diff --git a/src/thread.cpp b/src/thread.cpp
index 9400b38d06805813da71f993da1a8b22025dfab4..786258a2ed564961fdb75f67024944aaf8c25d49 100644 (file)
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -1,7 +1,7 @@
 /*
   Stockfish, a UCI chess playing engine derived from Glaurung 2.1
   Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
-  Copyright (C) 2008-2014 Marco Costalba, Joona Kiiski, Tord Romstad
+  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
 
   Stockfish is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -86,10 +86,11 @@ void ThreadBase::wait_for(volatile const bool& condition) {
 // Thread c'tor makes some init but does not launch any execution thread that
 // will be started only when c'tor returns.
 
-Thread::Thread() /* : splitPoints() */ { // Value-initialization bug in MSVC
+Thread::Thread() /* : splitPoints() */ { // Initialization of non POD broken in MSVC
 
   searching = false;
-  maxPly = splitPointsSize = 0;
+  maxPly = 0;
+  splitPointsSize = 0;
   activeSplitPoint = NULL;
   activePosition = NULL;
   idx = Threads.size(); // Starts from 0
@@ -123,7 +124,7 @@ bool Thread::available_to(const Thread* master) const {
 
   // Make a local copy to be sure it doesn't become zero under our feet while
   // testing next condition and so leading to an out of bounds access.
-  const int size = splitPointsSize;
+  const size_t size = splitPointsSize;
 
   // No split points means that the thread is available as a slave for any
   // other thread otherwise apply the "helpful master" concept if possible.
@@ -152,7 +153,7 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes
   // Pick and init the next available split point
   SplitPoint& sp = splitPoints[splitPointsSize];
 
-  sp.masterThread = this;
+  sp.master = this;
   sp.parentSplitPoint = activeSplitPoint;
   sp.slavesMask = 0, sp.slavesMask.set(idx);
   sp.depth = depth;
@@ -182,7 +183,8 @@ void Thread::split(Position& pos, Stack* ss, Value alpha, Value beta, Value* bes
 
   Thread* slave;
 
-  while ((slave = Threads.available_slave(this)) != NULL)
+  while (    sp.slavesMask.count() < MAX_SLAVES_PER_SPLITPOINT
+         && (slave = Threads.available_slave(this)) != NULL)
   {
       sp.slavesMask.set(slave->idx);
       slave->activeSplitPoint = &sp;