// 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().
-#if defined(_MSC_VER)
+#if defined(_WIN32) || defined(_WIN64)
DWORD WINAPI start_routine(LPVOID thread) {
#else
void* start_routine(void* thread) {
} }
-// wake_up() wakes up the thread, normally at the beginning of the search or,
-// if "sleeping threads" is used, when there is some work to do.
+// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
+// then calls do_timer_event(). If maxPly is 0 thread sleeps until is woken up.
+extern void check_time();
+
+void Thread::timer_loop() {
+
+ while (!do_exit)
+ {
+ lock_grab(sleepLock);
+ timed_wait(sleepCond, sleepLock, maxPly ? maxPly : INT_MAX);
+ lock_release(sleepLock);
+ check_time();
+ }
+}
+
+
+// Thread::main_loop() is where the main thread is parked waiting to be started
+// when there is a new search. Main thread will launch all the slave threads.
+
+void Thread::main_loop() {
+
+ while (true)
+ {
+ lock_grab(sleepLock);
+
+ do_sleep = true; // Always return to sleep after a search
+ is_searching = false;
+
+ while (do_sleep && !do_exit)
+ {
+ cond_signal(Threads.sleepCond); // Wake up UI thread if needed
+ cond_wait(sleepCond, sleepLock);
+ }
+
+ lock_release(sleepLock);
+
+ if (do_exit)
+ return;
+
+ is_searching = true;
+
+ Search::think();
+ }
+}
+
+
+// Thread::wake_up() wakes up the thread, normally at the beginning of the search
+// or, if "sleeping threads" is used, when there is some work to do.
void Thread::wake_up() {
}
+// Thread::wait_for_stop_or_ponderhit() is called when the maximum depth is
+// reached while the program is pondering. The point is to work around a wrinkle
+// in the UCI protocol: When pondering, the engine is not allowed to give a
+// "bestmove" before the GUI sends it a "stop" or "ponderhit" command. We simply
+// wait here until one of these commands (that raise StopRequest) is sent and
+// then return, after which the bestmove and pondermove will be printed.
+
+void Thread::wait_for_stop_or_ponderhit() {
+
+ Signals.stopOnPonderhit = true;
+
+ lock_grab(sleepLock);
+
+ while (!Signals.stop)
+ cond_wait(sleepCond, sleepLock);
+
+ lock_release(sleepLock);
+}
+
+
// cutoff_occurred() checks whether a beta cutoff has occurred in the current
// active split point, or in some ancestor of the split point.
bool Thread::cutoff_occurred() const {
- for (SplitPoint* sp = splitPoint; sp; sp = sp->parent)
- if (sp->is_betaCutoff)
+ for (SplitPoint* sp = curSplitPoint; sp; sp = sp->parent)
+ if (sp->cutoff)
return true;
return false;
// Make a local copy to be sure doesn't become zero under our feet while
// testing next condition and so leading to an out of bound access.
- int localActiveSplitPoints = activeSplitPoints;
+ int spCnt = splitPointsCnt;
// No active split points means that the thread is available as a slave for any
// other thread otherwise apply the "helpful master" concept if possible.
- if ( !localActiveSplitPoints
- || splitPoints[localActiveSplitPoints - 1].is_slave[master])
- return true;
-
- return false;
+ return !spCnt || (splitPoints[spCnt - 1].slavesMask & (1ULL << master));
}
-// read_uci_options() updates number of active threads and other parameters
-// according to the UCI options values. It is called before to start a new search.
+// read_uci_options() updates internal threads parameters from the corresponding
+// UCI options. It is called before to start a new search.
void ThreadsManager::read_uci_options() {
maxThreadsPerSplitPoint = Options["Max Threads per Split Point"];
minimumSplitDepth = Options["Min Split Depth"] * ONE_PLY;
useSleepingThreads = Options["Use Sleeping Threads"];
-
- set_size(Options["Threads"]);
}
void ThreadsManager::set_size(int cnt) {
- assert(cnt > 0 && cnt <= MAX_THREADS);
+ assert(cnt > 0 && cnt < MAX_THREADS);
activeThreads = cnt;
- for (int i = 1; i < MAX_THREADS; i++) // Ignore main thread
+ for (int i = 0; i < MAX_THREADS; i++)
if (i < activeThreads)
{
// Dynamically allocate pawn and material hash tables according to the
// possible threads if only few are used.
threads[i].pawnTable.init();
threads[i].materialTable.init();
+ threads[i].maxPly = 0;
threads[i].do_sleep = false;
+
+ if (!useSleepingThreads)
+ threads[i].wake_up();
}
else
threads[i].do_sleep = true;
void ThreadsManager::init() {
- // Initialize sleep condition and lock used by thread manager
cond_init(sleepCond);
- lock_init(threadsLock);
+ lock_init(splitLock);
- // Initialize thread's sleep conditions and split point locks
for (int i = 0; i <= MAX_THREADS; i++)
{
lock_init(threads[i].sleepLock);
cond_init(threads[i].sleepCond);
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
+ for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
lock_init(threads[i].splitPoints[j].lock);
}
threads[i].do_sleep = (i != 0); // Avoid a race with start_thinking()
threads[i].threadID = i;
- bool ok = thread_create(threads[i].handle, start_routine, threads[i]);
-
- if (!ok)
+ if (!thread_create(threads[i].handle, start_routine, threads[i]))
{
std::cerr << "Failed to create thread number " << i << std::endl;
::exit(EXIT_FAILURE);
for (int i = 0; i <= MAX_THREADS; i++)
{
- threads[i].do_terminate = true; // Search must be already finished
+ 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
- // Now we can safely destroy associated locks and wait conditions
lock_destroy(threads[i].sleepLock);
cond_destroy(threads[i].sleepCond);
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
+ for (int j = 0; j < MAX_SPLITPOINTS_PER_THREAD; j++)
lock_destroy(threads[i].splitPoints[j].lock);
}
- lock_destroy(threadsLock);
+ lock_destroy(splitLock);
cond_destroy(sleepCond);
}
}
-// split_point_finished() checks if all the slave threads of a given split
-// point have finished searching.
-
-bool ThreadsManager::split_point_finished(SplitPoint* sp) const {
-
- for (int i = 0; i < activeThreads; i++)
- if (sp->is_slave[i])
- return false;
-
- return true;
-}
-
-
// split() does the actual work of distributing the work at a node between
// several available threads. If it does not succeed in splitting the node
// (because no idle threads are available, or because we have no unused split
assert(pos.thread() >= 0 && pos.thread() < activeThreads);
assert(activeThreads > 1);
- int i, master = pos.thread();
+ int master = pos.thread();
Thread& masterThread = threads[master];
- // If we already have too many active split points, don't split
- if (masterThread.activeSplitPoints >= MAX_ACTIVE_SPLIT_POINTS)
+ if (masterThread.splitPointsCnt >= MAX_SPLITPOINTS_PER_THREAD)
return bestValue;
// Pick the next available split point from the split point stack
- SplitPoint* sp = &masterThread.splitPoints[masterThread.activeSplitPoints];
+ SplitPoint* sp = &masterThread.splitPoints[masterThread.splitPointsCnt];
- // Initialize the split point
- sp->parent = masterThread.splitPoint;
+ sp->parent = masterThread.curSplitPoint;
sp->master = master;
- sp->is_betaCutoff = false;
+ sp->cutoff = false;
+ sp->slavesMask = 1ULL << master;
sp->depth = depth;
sp->threatMove = threatMove;
sp->alpha = alpha;
sp->nodes = 0;
sp->ss = ss;
- for (i = 0; i < activeThreads; i++)
- sp->is_slave[i] = false;
-
- // If we are here it means we are not available
assert(masterThread.is_searching);
- int workersCnt = 1; // At least the master is included
+ int slavesCnt = 0;
// Try to allocate available threads and ask them to start searching setting
// is_searching flag. This must be done under lock protection to avoid concurrent
// allocation of the same slave by another master.
- lock_grab(threadsLock);
+ lock_grab(sp->lock);
+ lock_grab(splitLock);
- for (i = 0; !Fake && i < activeThreads && workersCnt < maxThreadsPerSplitPoint; i++)
+ for (int i = 0; i < activeThreads && !Fake; i++)
if (threads[i].is_available_to(master))
{
- workersCnt++;
- sp->is_slave[i] = true;
- threads[i].splitPoint = sp;
-
- // This makes the slave to exit from idle_loop()
- threads[i].is_searching = true;
+ sp->slavesMask |= 1ULL << i;
+ threads[i].curSplitPoint = sp;
+ threads[i].is_searching = true; // Slave leaves idle_loop()
if (useSleepingThreads)
threads[i].wake_up();
+
+ if (++slavesCnt + 1 >= maxThreadsPerSplitPoint) // Master is always included
+ break;
}
- lock_release(threadsLock);
+ masterThread.curSplitPoint = sp;
+ masterThread.splitPointsCnt++;
- // We failed to allocate even one slave, return
- if (!Fake && workersCnt == 1)
- return bestValue;
-
- masterThread.splitPoint = sp;
- masterThread.activeSplitPoints++;
+ lock_release(splitLock);
+ lock_release(sp->lock);
// Everything is set up. The master thread enters the idle loop, from which
// it will instantly launch a search, because its is_searching flag is set.
// We pass the split point as a parameter to the idle loop, which means that
// the thread will return from the idle loop when all slaves have finished
// their work at this split point.
- masterThread.idle_loop(sp);
-
- // In helpful master concept a master can help only a sub-tree of its split
- // point, and because here is all finished is not possible master is booked.
- assert(!masterThread.is_searching);
+ if (slavesCnt || Fake)
+ masterThread.idle_loop(sp);
// We have returned from the idle loop, which means that all threads are
- // finished. Note that changing state and decreasing activeSplitPoints is done
- // under lock protection to avoid a race with Thread::is_available_to().
- lock_grab(threadsLock);
+ // finished. Note that setting is_searching and decreasing activeSplitPoints is
+ // done under lock protection to avoid a race with Thread::is_available_to().
+ lock_grab(sp->lock); // To protect sp->nodes
+ lock_grab(splitLock);
masterThread.is_searching = true;
- masterThread.activeSplitPoints--;
-
- lock_release(threadsLock);
-
- masterThread.splitPoint = sp->parent;
+ masterThread.splitPointsCnt--;
+ masterThread.curSplitPoint = sp->parent;
pos.set_nodes_searched(pos.nodes_searched() + sp->nodes);
+ lock_release(splitLock);
+ lock_release(sp->lock);
+
return sp->bestValue;
}
template Value ThreadsManager::split<true>(Position&, Stack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
-// Thread::timer_loop() is where the timer thread waits maxPly milliseconds and
-// then calls do_timer_event(). If maxPly is 0 thread sleeps until is woken up.
-extern void check_time();
-
-void Thread::timer_loop() {
-
- while (!do_terminate)
- {
- lock_grab(sleepLock);
- timed_wait(sleepCond, sleepLock, maxPly ? maxPly : INT_MAX);
- lock_release(sleepLock);
- check_time();
- }
-}
-
-
// ThreadsManager::set_timer() is used to set the timer to trigger after msec
// milliseconds. If msec is 0 then timer is stopped.
}
-// Thread::main_loop() is where the main thread is parked waiting to be started
-// when there is a new search. Main thread will launch all the slave threads.
-
-void Thread::main_loop() {
-
- while (true)
- {
- lock_grab(sleepLock);
-
- do_sleep = true; // Always return to sleep after a search
- is_searching = false;
-
- while (do_sleep && !do_terminate)
- {
- cond_signal(Threads.sleepCond); // Wake up UI thread if needed
- cond_wait(sleepCond, sleepLock);
- }
-
- is_searching = true;
-
- lock_release(sleepLock);
-
- if (do_terminate)
- return;
-
- Search::think();
- }
-}
-
-
// ThreadsManager::start_thinking() is used by UI thread to wake up the main
// thread parked in main_loop() and starting a new search. If asyncMode is true
// then function returns immediately, otherwise caller is blocked waiting for
lock_release(main.sleepLock);
}
-
-
-// ThreadsManager::wait_for_stop_or_ponderhit() is called when the maximum depth
-// is reached while the program is pondering. The point is to work around a wrinkle
-// in the UCI protocol: When pondering, the engine is not allowed to give a
-// "bestmove" before the GUI sends it a "stop" or "ponderhit" command. We simply
-// wait here until one of these commands (that raise StopRequest) is sent and
-// then return, after which the bestmove and pondermove will be printed.
-
-void ThreadsManager::wait_for_stop_or_ponderhit() {
-
- Signals.stopOnPonderhit = true;
-
- Thread& main = threads[0];
-
- lock_grab(main.sleepLock);
-
- while (!Signals.stop)
- cond_wait(main.sleepCond, main.sleepLock);
-
- lock_release(main.sleepLock);
-}
projects / stockfish / blobdiff