namespace { extern "C" {
// start_routine() is the C function which is called when a new thread
- // is launched. It simply calls idle_loop() of the supplied thread. The first
- // and last thread are special. First one is the main search thread while the
- // last one mimics a timer, they run in main_loop() and timer_loop().
+ // is launched. It is a wrapper to member function pointed by start_fn
- long start_routine(Thread* th) {
+ long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; }
- if (th->threadID == 0)
- th->main_loop();
+} }
+
+
+// Thread c'tor starts a newly-created thread of execution that will call
+// the idle loop function pointed by start_fn going immediately to sleep.
- else if (th->threadID == MAX_THREADS)
- th->timer_loop();
+Thread::Thread(Fn fn) {
+
+ is_searching = do_exit = false;
+ maxPly = splitPointsCnt = 0;
+ curSplitPoint = NULL;
+ start_fn = fn;
+ threadID = Threads.size();
+ do_sleep = (threadID != 0); // Avoid a race with start_thinking()
+
+ lock_init(sleepLock);
+ cond_init(sleepCond);
- else
- th->idle_loop(NULL);
+ for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
+ lock_init(splitPoints[j].lock);
- return 0;
+ if (!thread_create(handle, start_routine, this))
+ {
+ std::cerr << "Failed to create thread number " << threadID << std::endl;
+ ::exit(EXIT_FAILURE);
}
+}
-} }
+
+// Thread d'tor will wait for thread termination before to return.
+
+Thread::~Thread() {
+
+ assert(do_sleep);
+
+ do_exit = true; // Search must be already finished
+ wake_up();
+
+ thread_join(handle); // Wait for thread termination
+
+ lock_destroy(sleepLock);
+ cond_destroy(sleepCond);
+
+ for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
+ lock_destroy(splitPoints[j].lock);
+}
// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
// read_uci_options() updates internal threads parameters from the corresponding
-// UCI options. It is called before to start a new search.
+// UCI options and creates/destroys threads to match the requested number. Thread
+// objects are dynamically allocated to avoid creating in advance all possible
+// threads, with included pawns and material tables, if only few are used.
void ThreadsManager::read_uci_options() {
maxThreadsPerSplitPoint = Options["Max Threads per Split Point"];
minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
useSleepingThreads = Options["Use Sleeping Threads"];
-}
+ int requested = Options["Threads"];
+ assert(requested > 0);
-// set_size() changes the number of active threads and raises do_sleep flag for
-// all the unused threads that will go immediately to sleep.
+ while (size() < requested)
+ threads.push_back(new Thread(&Thread::idle_loop));
-void ThreadsManager::set_size(int cnt) {
+ while (size() > requested)
+ {
+ delete threads.back();
+ threads.pop_back();
+ }
+}
- assert(cnt > 0 && cnt < MAX_THREADS);
- activeThreads = cnt;
+// wake_up() is called before a new search to start the threads that are waiting
+// on the sleep condition. If useSleepingThreads is set threads will be woken up
+// at split time.
- for (int i = 0; i < MAX_THREADS; i++)
- if (i < activeThreads)
- {
- // Dynamically allocate pawn and material hash tables according to the
- // number of active threads. This avoids preallocating memory for all
- // possible threads if only few are used.
- threads[i].pawnTable.init();
- threads[i].materialTable.init();
- threads[i].maxPly = 0;
+void ThreadsManager::wake_up() {
- threads[i].do_sleep = false;
+ for (int i = 1; i < size(); i++) // Main thread is already running
+ {
+ threads[i]->do_sleep = false;
- if (!useSleepingThreads)
- threads[i].wake_up();
- }
- else
- threads[i].do_sleep = true;
+ if (!useSleepingThreads)
+ threads[i]->wake_up();
+ }
}
-// init() is called during startup. Initializes locks and condition variables
-// and launches all threads sending them immediately to sleep.
-
-void ThreadsManager::init() {
-
- read_uci_options();
+// sleep() is called after the search to ask all the threads but the main to go
+// waiting on a sleep condition.
- cond_init(sleepCond);
- lock_init(splitLock);
+void ThreadsManager::sleep() {
- // Allocate main thread tables to call evaluate() also when not searching
- threads[0].pawnTable.init();
- threads[0].materialTable.init();
+ for (int i = 1; i < size(); i++) // Main thread will go to sleep by itself
+ threads[i]->do_sleep = true; // to avoid a race with start_thinking()
+}
- // Create and launch all the threads, threads will go immediately to sleep
- for (int i = 0; i <= MAX_THREADS; i++)
- {
- threads[i].is_searching = false;
- threads[i].do_sleep = (i != 0); // Avoid a race with start_thinking()
- threads[i].threadID = i;
- lock_init(threads[i].sleepLock);
- cond_init(threads[i].sleepCond);
+// init() is called during startup. Initializes locks and condition variables
+// and launches all threads sending them immediately to sleep.
- for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
- lock_init(threads[i].splitPoints[j].lock);
+void ThreadsManager::init() {
- if (!thread_create(threads[i].handle, start_routine, threads[i]))
- {
- std::cerr << "Failed to create thread number " << i << std::endl;
- ::exit(EXIT_FAILURE);
- }
- }
+ cond_init(sleepCond);
+ lock_init(splitLock);
+ timer = new Thread(&Thread::timer_loop);
+ threads.push_back(new Thread(&Thread::main_loop));
+ read_uci_options();
}
-// exit() is called to cleanly terminate the threads when the program finishes
+// exit() is called to cleanly terminate the threads before the program finishes
void ThreadsManager::exit() {
- for (int i = 0; i <= MAX_THREADS; i++)
- {
- assert(threads[i].do_sleep);
-
- threads[i].do_exit = true; // Search must be already finished
- threads[i].wake_up();
-
- thread_join(threads[i].handle); // Wait for thread termination
-
- lock_destroy(threads[i].sleepLock);
- cond_destroy(threads[i].sleepCond);
-
- for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
- lock_destroy(threads[i].splitPoints[j].lock);
- }
+ for (int i = 0; i < size(); i++)
+ delete threads[i];
+ delete timer;
lock_destroy(splitLock);
cond_destroy(sleepCond);
}
bool ThreadsManager::available_slave_exists(int master) const {
- assert(master >= 0 && master < activeThreads);
+ assert(master >= 0 && master < size());
- for (int i = 0; i < activeThreads; i++)
- if (threads[i].is_available_to(master))
+ for (int i = 0; i < size(); i++)
+ if (threads[i]->is_available_to(master))
return true;
return false;
assert(alpha < beta);
assert(beta <= VALUE_INFINITE);
assert(depth > DEPTH_ZERO);
- assert(pos.thread() >= 0 && pos.thread() < activeThreads);
- assert(activeThreads > 1);
int master = pos.thread();
- Thread& masterThread = threads[master];
+ Thread& masterThread = *threads[master];
if (masterThread.splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
return bestValue;
lock_grab(sp->lock);
lock_grab(splitLock);
- for (int i = 0; i < activeThreads && !Fake; i++)
- if (threads[i].is_available_to(master))
+ for (int i = 0; i < size() && !Fake; ++i)
+ if (threads[i]->is_available_to(master))
{
sp->slavesMask |= 1ULL << i;
- threads[i].curSplitPoint = sp;
- threads[i].is_searching = true; // Slave leaves idle_loop()
+ threads[i]->curSplitPoint = sp;
+ threads[i]->is_searching = true; // Slave leaves idle_loop()
if (useSleepingThreads)
- threads[i].wake_up();
+ threads[i]->wake_up();
if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
break;
void ThreadsManager::set_timer(int msec) {
- Thread& timer = threads[MAX_THREADS];
-
- lock_grab(timer.sleepLock);
- timer.maxPly = msec;
- cond_signal(timer.sleepCond); // Wake up and restart the timer
- lock_release(timer.sleepLock);
+ lock_grab(timer->sleepLock);
+ timer->maxPly = msec;
+ cond_signal(timer->sleepCond); // Wake up and restart the timer
+ lock_release(timer->sleepLock);
}
void ThreadsManager::start_thinking(const Position& pos, const LimitsType& limits,
const std::set<Move>& searchMoves, bool async) {
- Thread& main = threads[0];
+ Thread& main = *threads.front();
lock_grab(main.sleepLock);
void ThreadsManager::stop_thinking() {
- Thread& main = threads[0];
+ Thread& main = *threads.front();
Search::Signals.stop = true;
projects / stockfish / blobdiff