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) {
-
- if (th->threadID == 0)
- th->main_loop();
-
- else if (th->threadID == MAX_THREADS)
- th->timer_loop();
-
- else
- th->idle_loop(NULL);
-
- return 0;
- }
+ long start_routine(Thread* th) { (th->*(th->start_fn))(); return 0; }
} }
-Thread::Thread(int id) {
+// 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.
+
+Thread::Thread(Fn fn) {
- threadID = id;
- do_sleep = (id != 0); // Avoid a race with start_thinking()
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);
if (!thread_create(handle, start_routine, this))
{
- std::cerr << "Failed to create thread number " << id << std::endl;
+ 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);
// 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"];
- activeThreads = Options["Threads"];
-
- // Dynamically allocate Thread object according to the number of
- // active threads. This avoids preallocating memory for all possible
- // threads if only few are used.
- for (int i = 0; i < MAX_THREADS; i++)
- if (i < activeThreads && !threads[i])
- threads[i] = new Thread(i);
- else if (i >= activeThreads && threads[i])
- {
- delete threads[i];
- threads[i] = NULL;
- }
+ int requested = Options["Threads"];
+
+ assert(requested > 0);
+
+ while (size() < requested)
+ threads.push_back(new Thread(&Thread::idle_loop));
+
+ while (size() > requested)
+ {
+ delete threads.back();
+ threads.pop_back();
+ }
}
+// 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.
+
void ThreadsManager::wake_up() {
- for (int i = 0; i < activeThreads; i++)
+ for (int i = 1; i < size(); i++) // Main thread is already running
{
threads[i]->do_sleep = false;
- threads[i]->wake_up();
+
+ if (!useSleepingThreads)
+ threads[i]->wake_up();
}
}
+// sleep() is called after the search to ask all the threads but the main to go
+// waiting on a sleep condition.
+
void ThreadsManager::sleep() {
- for (int i = 0; i < activeThreads; i++)
- threads[i]->do_sleep = true;
+ 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()
}
cond_init(sleepCond);
lock_init(splitLock);
- timer = new Thread(MAX_THREADS);
- read_uci_options(); // Creates at least main thread
+ 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++)
- if (threads[i])
- delete threads[i];
+ for (int i = 0; i < size(); i++)
+ delete threads[i];
delete timer;
lock_destroy(splitLock);
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++)
+ for (int i = 0; i < size(); i++)
if (threads[i]->is_available_to(master))
return true;
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];
lock_grab(sp->lock);
lock_grab(splitLock);
- for (int i = 0; i < activeThreads && !Fake; i++)
+ for (int i = 0; i < size() && !Fake; ++i)
if (threads[i]->is_available_to(master))
{
sp->slavesMask |= 1ULL << i;
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