static void * APR_THREAD_FUNC eachThread(apr_thread_t *id, void *p)
{
test_mode_e test_mode = (test_mode_e)p;
lock_grab(test_mode);
++counter;
assert(apr_thread_mutex_lock(thread_mutex) == APR_SUCCESS);
assert(apr_thread_mutex_unlock(thread_mutex) == APR_SUCCESS);
lock_release(test_mode);
apr_thread_exit(id, 0);
return NULL;
}
Move MovePicker::get_next_move(Lock &lock) {
Move m;
lock_grab(&lock);
if(finished) {
lock_release(&lock);
return MOVE_NONE;
}
m = this->get_next_move();
if(m == MOVE_NONE)
finished = true;
lock_release(&lock);
return m;
}
void Thread::wake_up() {
lock_grab(&sleepLock);
cond_signal(&sleepCond);
lock_release(&sleepLock);
}
void ThreadsManager::split(Position& pos, SearchStack* ss, Value* alpha, const Value beta,
Value* bestValue, Depth depth, Move threatMove,
int moveCount, MovePicker* mp, bool pvNode) {
assert(pos.is_ok());
assert(*bestValue >= -VALUE_INFINITE);
assert(*bestValue <= *alpha);
assert(*alpha < beta);
assert(beta <= VALUE_INFINITE);
assert(depth > DEPTH_ZERO);
assert(pos.thread() >= 0 && pos.thread() < activeThreads);
assert(activeThreads > 1);
int i, master = pos.thread();
Thread& masterThread = threads[master];
lock_grab(&mpLock);
// If no other thread is available to help us, or if we have too many
// active split points, don't split.
if ( !available_slave_exists(master)
|| masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS)
{
lock_release(&mpLock);
return;
}
// Pick the next available split point object from the split point stack
SplitPoint& splitPoint = masterThread.splitPoints[masterThread.activeSplitPoints++];
// Initialize the split point object
splitPoint.parent = masterThread.splitPoint;
splitPoint.master = master;
splitPoint.is_betaCutoff = false;
splitPoint.depth = depth;
splitPoint.threatMove = threatMove;
splitPoint.alpha = *alpha;
splitPoint.beta = beta;
splitPoint.pvNode = pvNode;
splitPoint.bestValue = *bestValue;
splitPoint.mp = mp;
splitPoint.moveCount = moveCount;
splitPoint.pos = &pos;
splitPoint.nodes = 0;
splitPoint.ss = ss;
for (i = 0; i < activeThreads; i++)
splitPoint.is_slave[i] = false;
masterThread.splitPoint = &splitPoint;
// If we are here it means we are not available
assert(masterThread.state != Thread::AVAILABLE);
int workersCnt = 1; // At least the master is included
// Allocate available threads setting state to THREAD_BOOKED
for (i = 0; !Fake && i < activeThreads && workersCnt < maxThreadsPerSplitPoint; i++)
if (i != master && threads[i].is_available_to(master))
{
threads[i].state = Thread::BOOKED;
threads[i].splitPoint = &splitPoint;
splitPoint.is_slave[i] = true;
workersCnt++;
}
assert(Fake || workersCnt > 1);
// We can release the lock because slave threads are already booked and master is not available
lock_release(&mpLock);
// Tell the threads that they have work to do. This will make them leave
// their idle loop.
for (i = 0; i < activeThreads; i++)
if (i == master || splitPoint.is_slave[i])
{
assert(i == master || threads[i].state == Thread::BOOKED);
threads[i].state = Thread::WORKISWAITING; // This makes the slave to exit from idle_loop()
if (useSleepingThreads && i != master)
threads[i].wake_up();
}
// Everything is set up. The master thread enters the idle loop, from
// which it will instantly launch a search, because its state is
// THREAD_WORKISWAITING. We send the split point as a second parameter to the
// idle loop, which means that the main thread will return from the idle
// loop when all threads have finished their work at this split point.
idle_loop(master, &splitPoint);
// We have returned from the idle loop, which means that all threads are
// finished. Update alpha and bestValue, and return.
lock_grab(&mpLock);
*alpha = splitPoint.alpha;
*bestValue = splitPoint.bestValue;
masterThread.activeSplitPoints--;
masterThread.splitPoint = splitPoint.parent;
pos.set_nodes_searched(pos.nodes_searched() + splitPoint.nodes);
lock_release(&mpLock);
}
