#include <iostream>
+#include "search.h"
#include "thread.h"
#include "ucioption.h"
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 threadID.
- // There are two versions of this function; one for POSIX threads and
- // one for Windows threads.
+ // is launched. It simply calls idle_loop() of the supplied thread. The
+ // last two threads are dedicated to read input from GUI and to mimic a
+ // timer, so they run in listener_loop() and timer_loop() respectively.
#if defined(_MSC_VER)
-
- DWORD WINAPI start_routine(LPVOID threadID) {
-
- Threads[*(int*)threadID].idle_loop(NULL);
- return 0;
- }
-
+ DWORD WINAPI start_routine(LPVOID thread) {
#else
+ void* start_routine(void* thread) {
+#endif
- void* start_routine(void* threadID) {
+ if (((Thread*)thread)->threadID == 0)
+ ((Thread*)thread)->main_loop();
- Threads[*(int*)threadID].idle_loop(NULL);
- return NULL;
- }
+ else if (((Thread*)thread)->threadID == MAX_THREADS)
+ ((Thread*)thread)->timer_loop();
+ else
+ ((Thread*)thread)->idle_loop(NULL);
-#endif
+ return 0;
+ }
} }
}
-// cutoff_occurred() checks whether a beta cutoff has occurred in
-// the thread's currently active split point, or in some ancestor of
-// the current split point.
+// 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 {
bool Thread::is_available_to(int master) const {
- if (state != AVAILABLE)
+ if (is_searching)
return false;
// Make a local copy to be sure doesn't become zero under our feet while
activeThreads = cnt;
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 1; i < MAX_THREADS; i++) // Ignore main thread
if (i < activeThreads)
{
// Dynamically allocate pawn and material hash tables according to the
void ThreadsManager::init() {
- // Threads will go to sleep as soon as created, only main thread is kept alive
- set_size(1);
- threads[0].state = Thread::SEARCHING;
- threads[0].threadID = 0;
+ // Initialize sleep condition used to block waiting for end of searching
+ cond_init(&sleepCond);
// Initialize threads lock, used when allocating slaves during splitting
lock_init(&threadsLock);
// Initialize sleep and split point locks
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 0; i <= MAX_THREADS; i++)
{
lock_init(&threads[i].sleepLock);
cond_init(&threads[i].sleepCond);
lock_init(&(threads[i].splitPoints[j].lock));
}
- // Create and startup all the threads but the main that is already running
- for (int i = 1; i < MAX_THREADS; i++)
+ // Initialize main thread's associated data
+ threads[0].pawnTable.init();
+ threads[0].materialTable.init();
+
+ // Create and launch all the threads, threads will go immediately to sleep
+ for (int i = 0; i <= MAX_THREADS; i++)
{
- threads[i].state = Thread::AVAILABLE;
+ threads[i].is_searching = false;
+ threads[i].do_sleep = true;
threads[i].threadID = i;
#if defined(_MSC_VER)
- threads[i].handle = CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i].threadID, 0, NULL);
+ threads[i].handle = CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i], 0, NULL);
bool ok = (threads[i].handle != NULL);
#else
- bool ok = (pthread_create(&threads[i].handle, NULL, start_routine, (void*)&threads[i].threadID) == 0);
+ bool ok = (pthread_create(&threads[i].handle, NULL, start_routine, (void*)&threads[i]) == 0);
#endif
if (!ok)
{
- std::cout << "Failed to create thread number " << i << std::endl;
+ std::cerr << "Failed to create thread number " << i << std::endl;
::exit(EXIT_FAILURE);
}
}
void ThreadsManager::exit() {
- for (int i = 0; i < MAX_THREADS; i++)
+ for (int i = 0; i <= MAX_THREADS; i++)
{
- // Wake up all the slave threads and wait for termination
- if (i != 0)
- {
- threads[i].do_terminate = true;
- threads[i].wake_up();
+ threads[i].do_terminate = true;
+ threads[i].wake_up();
+ // Wait for slave termination
#if defined(_MSC_VER)
- WaitForSingleObject(threads[i].handle, 0);
- CloseHandle(threads[i].handle);
+ WaitForSingleObject(threads[i].handle, 0);
+ CloseHandle(threads[i].handle);
#else
- pthread_join(threads[i].handle, NULL);
- pthread_detach(threads[i].handle);
+ pthread_join(threads[i].handle, NULL);
#endif
- }
// Now we can safely destroy locks and wait conditions
lock_destroy(&threads[i].sleepLock);
}
lock_destroy(&threadsLock);
+ 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
Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value beta,
Value bestValue, Depth depth, Move threatMove,
int moveCount, MovePicker* mp, int nodeType) {
- assert(pos.is_ok());
+ assert(pos.pos_is_ok());
assert(bestValue >= -VALUE_INFINITE);
assert(bestValue <= alpha);
assert(alpha < beta);
sp->is_slave[i] = false;
// If we are here it means we are not available
- assert(masterThread.state == Thread::SEARCHING);
+ assert(masterThread.is_searching);
int workersCnt = 1; // At least the master is included
threads[i].splitPoint = sp;
// This makes the slave to exit from idle_loop()
- threads[i].state = Thread::WORKISWAITING;
+ threads[i].is_searching = true;
if (useSleepingThreads)
threads[i].wake_up();
masterThread.splitPoint = sp;
masterThread.activeSplitPoints++;
- masterThread.state = Thread::WORKISWAITING;
- // 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.
+ // 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, and
// because here is all finished is not possible master is booked.
- assert(masterThread.state == Thread::AVAILABLE);
+ assert(!masterThread.is_searching);
// 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);
- masterThread.state = Thread::SEARCHING;
+ masterThread.is_searching = true;
masterThread.activeSplitPoints--;
lock_release(&threadsLock);
// Explicit template instantiations
template Value ThreadsManager::split<false>(Position&, SearchStack*, Value, Value, Value, Depth, Move, int, MovePicker*, int);
template Value ThreadsManager::split<true>(Position&, SearchStack*, 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().
+
+void Thread::timer_loop() {
+
+ while (!do_terminate)
+ {
+ lock_grab(&sleepLock);
+ timed_wait(&sleepCond, &sleepLock, maxPly ? maxPly : INT_MAX);
+ lock_release(&sleepLock);
+ do_timer_event();
+ }
+}
+
+
+// ThreadsManager::set_timer() is used to set the timer to trigger after msec
+// milliseconds. If msec is 0 then timer is stopped.
+
+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);
+}
+
+
+// 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
+// the search to finish.
+
+void ThreadsManager::start_thinking(bool asyncMode) {
+
+ Thread& main = threads[0];
+
+ lock_grab(&main.sleepLock);
+
+ // Wait main thread has finished before to launch a new search
+ while (!main.do_sleep)
+ cond_wait(&sleepCond, &main.sleepLock);
+
+ // Reset signals before to start the search
+ memset((void*)&Search::Signals, 0, sizeof(Search::Signals));
+
+ main.do_sleep = false;
+ cond_signal(&main.sleepCond); // Wake up main thread
+
+ if (!asyncMode)
+ cond_wait(&sleepCond, &main.sleepLock);
+
+ 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 return, after which the bestmove and pondermove will be printed.
+
+void ThreadsManager::wait_for_stop_or_ponderhit() {
+
+ Search::Signals.stopOnPonderhit = true;
+
+ Thread& main = threads[0];
+
+ lock_grab(&main.sleepLock);
+
+ while (!Search::Signals.stop)
+ cond_wait(&main.sleepCond, &main.sleepLock);
+
+ lock_release(&main.sleepLock);
+}
projects / stockfish / blobdiff