thread.maxPly = ss->ply;
// Step 1. Initialize node
- if (!SpNode)
- {
- ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE;
- (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
- (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
- }
- else
+ if (SpNode)
{
- sp = ss->sp;
tte = NULL;
ttMove = excludedMove = MOVE_NONE;
+ sp = ss->sp;
threatMove = sp->threatMove;
+ bestValue = sp->bestValue;
+ moveCount = sp->moveCount; // Lock must be held here
+
+ assert(bestValue > -VALUE_INFINITE && moveCount > 0);
+
goto split_point_start;
}
+ else
+ {
+ ss->currentMove = ss->bestMove = threatMove = (ss+1)->excludedMove = MOVE_NONE;
+ (ss+1)->skipNullMove = false; (ss+1)->reduction = DEPTH_ZERO;
+ (ss+2)->killers[0] = (ss+2)->killers[1] = MOVE_NONE;
+
+ }
// Step 2. Check for aborted search and immediate draw
// Enforce node limit here. FIXME: This only works with 1 search thread.
&& !excludedMove // Recursive singular search is not allowed
&& (tte->type() & VALUE_TYPE_LOWER)
&& tte->depth() >= depth - 3 * ONE_PLY;
- if (SpNode)
- {
- lock_grab(sp->lock);
- bestValue = sp->bestValue;
- moveCount = sp->moveCount;
-
- assert(bestValue > -VALUE_INFINITE && moveCount > 0);
- }
// Step 11. Loop through moves
// Loop through all pseudo-legal moves until no moves remain or a beta cutoff occurs
}
}
- if (SpNode)
- {
- // Here we have the lock still grabbed
- sp->is_slave[pos.thread()] = false;
- sp->nodes += pos.nodes_searched();
- lock_release(sp->lock);
- }
-
assert(bestValue > -VALUE_INFINITE && bestValue < VALUE_INFINITE);
return bestValue;
/// Thread::idle_loop() is where the thread is parked when it has no work to do.
-/// The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint object
-/// for which the thread is the master.
+/// The parameter 'master_sp', if non-NULL, is a pointer to an active SplitPoint
+/// object for which the thread is the master.
-void Thread::idle_loop(SplitPoint* sp) {
+void Thread::idle_loop(SplitPoint* sp_master) {
- while (true)
+ // If this thread is the master of a split point and all slaves have
+ // finished their work at this split point, return from the idle loop.
+ while (!sp_master || sp_master->slavesMask)
{
// If we are not searching, wait for a condition to be signaled
// instead of wasting CPU time polling for work.
while ( do_sleep
- || do_terminate
- || (Threads.use_sleeping_threads() && !is_searching))
+ || do_exit
+ || (!is_searching && Threads.use_sleeping_threads()))
{
- assert((!sp && threadID) || Threads.use_sleeping_threads());
-
- if (do_terminate)
+ if (do_exit)
{
- assert(!sp);
+ assert(!sp_master);
return;
}
lock_grab(sleepLock);
// If we are master and all slaves have finished don't go to sleep
- if (sp && Threads.split_point_finished(sp))
+ if (sp_master && !sp_master->slavesMask)
{
lock_release(sleepLock);
break;
// If this thread has been assigned work, launch a search
if (is_searching)
{
- assert(!do_terminate);
+ assert(!do_sleep && !do_exit);
// Copy split point position and search stack and call search()
Stack ss[MAX_PLY_PLUS_2];
- SplitPoint* tsp = splitPoint;
- Position pos(*tsp->pos, threadID);
-
- memcpy(ss, tsp->ss - 1, 4 * sizeof(Stack));
- (ss+1)->sp = tsp;
-
- if (tsp->nodeType == Root)
- search<SplitPointRoot>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
- else if (tsp->nodeType == PV)
- search<SplitPointPV>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
- else if (tsp->nodeType == NonPV)
- search<SplitPointNonPV>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+ SplitPoint* sp = splitPoint;
+ Position pos(*sp->pos, threadID);
+
+ memcpy(ss, sp->ss - 1, 4 * sizeof(Stack));
+ (ss+1)->sp = sp;
+
+ lock_grab(sp->lock);
+
+ if (sp->nodeType == Root)
+ search<SplitPointRoot>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
+ else if (sp->nodeType == PV)
+ search<SplitPointPV>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
+ else if (sp->nodeType == NonPV)
+ search<SplitPointNonPV>(pos, ss+1, sp->alpha, sp->beta, sp->depth);
else
assert(false);
assert(is_searching);
+ // We return from search with lock held
+ sp->slavesMask &= ~(1ULL << threadID);
+ sp->nodes += pos.nodes_searched();
+ lock_release(sp->lock);
+
is_searching = false;
// Wake up master thread so to allow it to return from the idle loop in
// case we are the last slave of the split point.
if ( Threads.use_sleeping_threads()
- && threadID != tsp->master
- && !Threads[tsp->master].is_searching)
- Threads[tsp->master].wake_up();
- }
-
- // If this thread is the master of a split point and all slaves have
- // finished their work at this split point, return from the idle loop.
- if (sp && Threads.split_point_finished(sp))
- {
- // Because sp->is_slave[] is reset under lock protection,
- // be sure sp->lock has been released before to return.
- lock_grab(sp->lock);
- lock_release(sp->lock);
- return;
+ && threadID != sp->master
+ && !Threads[sp->master].is_searching)
+ Threads[sp->master].wake_up();
}
}
}
projects / stockfish / blobdiff