#include "move.h"
#include "movegen.h"
#include "movepick.h"
-#include "lock.h"
#include "search.h"
#include "timeman.h"
#include "thread.h"
const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
inline bool piece_is_slider(Piece p) { return Slidings[p]; }
- // ThreadsManager class is used to handle all the threads related stuff like init,
- // starting, parking and, the most important, launching a slave thread at a split
- // point. All the access to shared thread data is done through this class.
-
- class ThreadsManager {
- /* As long as the single ThreadsManager object is defined as a global we don't
- need to explicitly initialize to zero its data members because variables with
- static storage duration are automatically set to zero before enter main()
- */
- public:
- Thread& operator[](int threadID) { return threads[threadID]; }
- void init_threads();
- void exit_threads();
-
- int min_split_depth() const { return minimumSplitDepth; }
- int active_threads() const { return activeThreads; }
- void set_active_threads(int cnt) { activeThreads = cnt; }
-
- void read_uci_options();
- bool available_thread_exists(int master) const;
- bool thread_is_available(int slave, int master) const;
- bool cutoff_at_splitpoint(int threadID) const;
- void idle_loop(int threadID, SplitPoint* sp);
-
- template <bool Fake>
- void split(Position& pos, SearchStack* ss, Value* alpha, const Value beta, Value* bestValue,
- Depth depth, Move threatMove, int moveCount, MovePicker* mp, bool pvNode);
- private:
- Lock mpLock;
- Depth minimumSplitDepth;
- int maxThreadsPerSplitPoint;
- bool useSleepingThreads;
- int activeThreads;
- volatile bool allThreadsShouldExit;
- Thread threads[MAX_THREADS];
- };
-
-
// RootMove struct is used for moves at the root of the tree. For each root
// move, we store two scores, a node count, and a PV (really a refutation
// in the case of moves which fail low). Value pv_score is normally set at
const Value FutilityMarginQS = Value(0x80);
// Futility lookup tables (initialized at startup) and their access functions
- Value FutilityMarginsMatrix[16][64]; // [depth][moveNumber]
- int FutilityMoveCountArray[32]; // [depth]
+ Value FutilityMargins[16][64]; // [depth][moveNumber]
+ int FutilityMoveCounts[32]; // [depth]
inline Value futility_margin(Depth d, int mn) {
- return d < 7 * ONE_PLY ? FutilityMarginsMatrix[Max(d, 1)][Min(mn, 63)]
- : 2 * VALUE_INFINITE;
+ return d < 7 * ONE_PLY ? FutilityMargins[Max(d, 1)][Min(mn, 63)]
+ : 2 * VALUE_INFINITE;
}
inline int futility_move_count(Depth d) {
- return d < 16 * ONE_PLY ? FutilityMoveCountArray[d] : MAX_MOVES;
+ return d < 16 * ONE_PLY ? FutilityMoveCounts[d] : MAX_MOVES;
}
// Step 14. Reduced search
// Reduction lookup tables (initialized at startup) and their access function
- int8_t ReductionMatrix[2][64][64]; // [pv][depth][moveNumber]
+ int8_t Reductions[2][64][64]; // [pv][depth][moveNumber]
- template <NodeType PV>
- inline Depth reduction(Depth d, int mn) { return (Depth) ReductionMatrix[PV][Min(d / ONE_PLY, 63)][Min(mn, 63)]; }
+ template <NodeType PV> inline Depth reduction(Depth d, int mn) {
+
+ return (Depth) Reductions[PV][Min(d / ONE_PLY, 63)][Min(mn, 63)];
+ }
// Easy move margin. An easy move candidate must be at least this much
// better than the second best move.
bool SkillLevelEnabled;
RKISS RK;
- // Multi-threads manager
- ThreadsManager ThreadsMgr;
-
// Node counters, used only by thread[0] but try to keep in different cache
// lines (64 bytes each) from the heavy multi-thread read accessed variables.
bool SendSearchedNodes;
void poll(const Position& pos);
void wait_for_stop_or_ponderhit();
-#if !defined(_MSC_VER)
- void* init_thread(void* threadID);
-#else
- DWORD WINAPI init_thread(LPVOID threadID);
-#endif
-
// MovePickerExt is an extended MovePicker class used to choose at compile time
// the proper move source according to the type of node.
} // namespace
-/// init_threads() is called during startup. It initializes various lookup tables
-/// and creates and launches search threads.
+/// init_search() is called during startup to initialize various lookup tables
-void init_threads() {
+void init_search() {
int d; // depth (ONE_PLY == 2)
int hd; // half depth (ONE_PLY == 1)
{
double pvRed = log(double(hd)) * log(double(mc)) / 3.0;
double nonPVRed = 0.33 + log(double(hd)) * log(double(mc)) / 2.25;
- ReductionMatrix[PV][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0);
- ReductionMatrix[NonPV][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0);
+ Reductions[PV][hd][mc] = (int8_t) ( pvRed >= 1.0 ? floor( pvRed * int(ONE_PLY)) : 0);
+ Reductions[NonPV][hd][mc] = (int8_t) (nonPVRed >= 1.0 ? floor(nonPVRed * int(ONE_PLY)) : 0);
}
// Init futility margins array
for (d = 1; d < 16; d++) for (mc = 0; mc < 64; mc++)
- FutilityMarginsMatrix[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
+ FutilityMargins[d][mc] = Value(112 * int(log(double(d * d) / 2) / log(2.0) + 1.001) - 8 * mc + 45);
// Init futility move count array
for (d = 0; d < 32; d++)
- FutilityMoveCountArray[d] = int(3.001 + 0.25 * pow(d, 2.0));
-
- // Create and startup threads
- ThreadsMgr.init_threads();
+ FutilityMoveCounts[d] = int(3.001 + 0.25 * pow(d, 2.0));
}
-/// exit_threads() is a trampoline to access ThreadsMgr from outside of current file
-void exit_threads() { ThreadsMgr.exit_threads(); }
-
-
/// perft() is our utility to verify move generation. All the legal moves up to
/// given depth are generated and counted and the sum returned.
SkillLevel = Options["Skill level"].value<int>();
read_evaluation_uci_options(pos.side_to_move());
+ ThreadsMgr.read_uci_options();
+
+ // If needed allocate pawn and material hash tables and adjust TT size
+ ThreadsMgr.init_hash_tables();
+ TT.set_size(Options["Hash"].value<int>());
if (Options["Clear Hash"].value<bool>())
{
Options["Clear Hash"].set_value("false");
TT.clear();
}
- TT.set_size(Options["Hash"].value<int>());
// Do we have to play with skill handicap? In this case enable MultiPV that
// we will use behind the scenes to retrieve a set of possible moves.
SkillLevelEnabled = (SkillLevel < 20);
MultiPV = (SkillLevelEnabled ? Max(UCIMultiPV, 4) : UCIMultiPV);
- // Set the number of active threads
- ThreadsMgr.read_uci_options();
- init_eval(ThreadsMgr.active_threads());
-
// Wake up needed threads and reset maxPly counter
for (int i = 0; i < ThreadsMgr.active_threads(); i++)
{
}
- // init_thread() is the function which is called when a new thread is
- // launched. It simply calls the idle_loop() function with the supplied
- // threadID. There are two versions of this function; one for POSIX
- // threads and one for Windows threads.
-
-#if !defined(_MSC_VER)
-
- void* init_thread(void* threadID) {
-
- ThreadsMgr.idle_loop(*(int*)threadID, NULL);
- return NULL;
- }
-
-#else
-
- DWORD WINAPI init_thread(LPVOID threadID) {
-
- ThreadsMgr.idle_loop(*(int*)threadID, NULL);
- return 0;
- }
-
-#endif
-
-
- /// The ThreadsManager class
-
-
- // read_uci_options() updates number of active threads and other internal
- // parameters according to the UCI options values. It is called before
- // to start a new search.
-
- void ThreadsManager::read_uci_options() {
-
- maxThreadsPerSplitPoint = Options["Maximum Number of Threads per Split Point"].value<int>();
- minimumSplitDepth = Options["Minimum Split Depth"].value<int>() * ONE_PLY;
- useSleepingThreads = Options["Use Sleeping Threads"].value<bool>();
- activeThreads = Options["Threads"].value<int>();
- }
-
-
- // idle_loop() is where the threads are parked when they have no work to do.
- // The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint
- // object for which the current thread is the master.
-
- void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) {
-
- assert(threadID >= 0 && threadID < MAX_THREADS);
-
- int i;
- bool allFinished;
-
- while (true)
- {
- // Slave threads can exit as soon as AllThreadsShouldExit raises,
- // master should exit as last one.
- if (allThreadsShouldExit)
- {
- assert(!sp);
- threads[threadID].state = THREAD_TERMINATED;
- return;
- }
-
- // If we are not thinking, wait for a condition to be signaled
- // instead of wasting CPU time polling for work.
- while ( threadID >= activeThreads
- || threads[threadID].state == THREAD_INITIALIZING
- || (useSleepingThreads && threads[threadID].state == THREAD_AVAILABLE))
- {
- assert(!sp || useSleepingThreads);
- assert(threadID != 0 || useSleepingThreads);
-
- if (threads[threadID].state == THREAD_INITIALIZING)
- threads[threadID].state = THREAD_AVAILABLE;
-
- // Grab the lock to avoid races with Thread::wake_up()
- lock_grab(&threads[threadID].sleepLock);
-
- // If we are master and all slaves have finished do not go to sleep
- for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
- allFinished = (i == activeThreads);
-
- if (allFinished || allThreadsShouldExit)
- {
- lock_release(&threads[threadID].sleepLock);
- break;
- }
-
- // Do sleep here after retesting sleep conditions
- if (threadID >= activeThreads || threads[threadID].state == THREAD_AVAILABLE)
- cond_wait(&threads[threadID].sleepCond, &threads[threadID].sleepLock);
-
- lock_release(&threads[threadID].sleepLock);
- }
-
- // If this thread has been assigned work, launch a search
- if (threads[threadID].state == THREAD_WORKISWAITING)
- {
- assert(!allThreadsShouldExit);
-
- threads[threadID].state = THREAD_SEARCHING;
-
- // Copy split point position and search stack and call search()
- // with SplitPoint template parameter set to true.
- SearchStack ss[PLY_MAX_PLUS_2];
- SplitPoint* tsp = threads[threadID].splitPoint;
- Position pos(*tsp->pos, threadID);
-
- memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack));
- (ss+1)->sp = tsp;
-
- if (tsp->pvNode)
- search<PV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
- else
- search<NonPV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
-
- assert(threads[threadID].state == THREAD_SEARCHING);
-
- threads[threadID].state = THREAD_AVAILABLE;
-
- // Wake up master thread so to allow it to return from the idle loop in
- // case we are the last slave of the split point.
- if ( useSleepingThreads
- && threadID != tsp->master
- && threads[tsp->master].state == THREAD_AVAILABLE)
- threads[tsp->master].wake_up();
- }
-
- // If this thread is the master of a split point and all slaves have
- // finished their work at this split point, return from the idle loop.
- for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
- allFinished = (i == activeThreads);
-
- if (allFinished)
- {
- // Because sp->slaves[] is reset under lock protection,
- // be sure sp->lock has been released before to return.
- lock_grab(&(sp->lock));
- lock_release(&(sp->lock));
-
- // 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(threads[threadID].state == THREAD_AVAILABLE);
-
- threads[threadID].state = THREAD_SEARCHING;
- return;
- }
- }
- }
-
-
- // init_threads() is called during startup. Initializes locks and condition
- // variables and launches all threads sending them immediately to sleep.
-
- void ThreadsManager::init_threads() {
-
- int i, arg[MAX_THREADS];
- bool ok;
-
- // This flag is needed to properly end the threads when program exits
- allThreadsShouldExit = false;
-
- // Threads will sent to sleep as soon as created, only main thread is kept alive
- activeThreads = 1;
-
- lock_init(&mpLock);
+ // When playing with strength handicap choose best move among the MultiPV set
+ // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen.
+ void do_skill_level(Move* best, Move* ponder) {
- for (i = 0; i < MAX_THREADS; i++)
- {
- // Initialize thread and split point locks
- lock_init(&threads[i].sleepLock);
- cond_init(&threads[i].sleepCond);
+ assert(MultiPV > 1);
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
- lock_init(&(threads[i].splitPoints[j].lock));
+ // Rml list is already sorted by pv_score in descending order
+ int s;
+ int max_s = -VALUE_INFINITE;
+ int size = Min(MultiPV, (int)Rml.size());
+ int max = Rml[0].pv_score;
+ int var = Min(max - Rml[size - 1].pv_score, PawnValueMidgame);
+ int wk = 120 - 2 * SkillLevel;
- // All threads but first should be set to THREAD_INITIALIZING
- threads[i].state = (i == 0 ? THREAD_SEARCHING : THREAD_INITIALIZING);
- }
+ // PRNG sequence should be non deterministic
+ for (int i = abs(get_system_time() % 50); i > 0; i--)
+ RK.rand<unsigned>();
- // Create and startup the threads
- for (i = 1; i < MAX_THREADS; i++)
+ // Choose best move. For each move's score we add two terms both dependent
+ // on wk, one deterministic and bigger for weaker moves, and one random,
+ // then we choose the move with the resulting highest score.
+ for (int i = 0; i < size; i++)
{
- arg[i] = i;
-
-#if !defined(_MSC_VER)
- pthread_t pthread[1];
- ok = (pthread_create(pthread, NULL, init_thread, (void*)(&arg[i])) == 0);
- pthread_detach(pthread[0]);
-#else
- ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&arg[i]), 0, NULL) != NULL);
-#endif
- if (!ok)
- {
- cout << "Failed to create thread number " << i << endl;
- exit(EXIT_FAILURE);
- }
-
- // Wait until the thread has finished launching and is gone to sleep
- while (threads[i].state == THREAD_INITIALIZING) {}
- }
- }
-
-
- // exit_threads() is called when the program exits. It makes all the
- // helper threads exit cleanly.
+ s = Rml[i].pv_score;
- void ThreadsManager::exit_threads() {
+ // Don't allow crazy blunders even at very low skills
+ if (i > 0 && Rml[i-1].pv_score > s + EasyMoveMargin)
+ break;
- // Force the woken up threads to exit idle_loop() and hence terminate
- allThreadsShouldExit = true;
+ // This is our magical formula
+ s += ((max - s) * wk + var * (RK.rand<unsigned>() % wk)) / 128;
- for (int i = 0; i < MAX_THREADS; i++)
- {
- // Wake up all the threads and waits for termination
- if (i != 0)
+ if (s > max_s)
{
- threads[i].wake_up();
- while (threads[i].state != THREAD_TERMINATED) {}
+ max_s = s;
+ *best = Rml[i].pv[0];
+ *ponder = Rml[i].pv[1];
}
-
- // Now we can safely destroy the locks and wait conditions
- lock_destroy(&threads[i].sleepLock);
- cond_destroy(&threads[i].sleepCond);
-
- for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
- lock_destroy(&(threads[i].splitPoints[j].lock));
- }
-
- lock_destroy(&mpLock);
- }
-
-
- // cutoff_at_splitpoint() checks whether a beta cutoff has occurred in
- // the thread's currently active split point, or in some ancestor of
- // the current split point.
-
- bool ThreadsManager::cutoff_at_splitpoint(int threadID) const {
-
- assert(threadID >= 0 && threadID < activeThreads);
-
- SplitPoint* sp = threads[threadID].splitPoint;
-
- for ( ; sp && !sp->betaCutoff; sp = sp->parent) {}
- return sp != NULL;
- }
-
-
- // thread_is_available() checks whether the thread with threadID "slave" is
- // available to help the thread with threadID "master" at a split point. An
- // obvious requirement is that "slave" must be idle. With more than two
- // threads, this is not by itself sufficient: If "slave" is the master of
- // some active split point, it is only available as a slave to the other
- // threads which are busy searching the split point at the top of "slave"'s
- // split point stack (the "helpful master concept" in YBWC terminology).
-
- bool ThreadsManager::thread_is_available(int slave, int master) const {
-
- assert(slave >= 0 && slave < activeThreads);
- assert(master >= 0 && master < activeThreads);
- assert(activeThreads > 1);
-
- if (threads[slave].state != THREAD_AVAILABLE || slave == master)
- return false;
-
- // Make a local copy to be sure doesn't change under our feet
- int localActiveSplitPoints = threads[slave].activeSplitPoints;
-
- // No active split points means that the thread is available as
- // a slave for any other thread.
- if (localActiveSplitPoints == 0 || activeThreads == 2)
- return true;
-
- // Apply the "helpful master" concept if possible. Use localActiveSplitPoints
- // that is known to be > 0, instead of threads[slave].activeSplitPoints that
- // could have been set to 0 by another thread leading to an out of bound access.
- if (threads[slave].splitPoints[localActiveSplitPoints - 1].slaves[master])
- return true;
-
- return false;
- }
-
-
- // available_thread_exists() tries to find an idle thread which is available as
- // a slave for the thread with threadID "master".
-
- bool ThreadsManager::available_thread_exists(int master) const {
-
- assert(master >= 0 && master < activeThreads);
- assert(activeThreads > 1);
-
- for (int i = 0; i < activeThreads; i++)
- if (thread_is_available(i, master))
- return true;
-
- return false;
- }
-
-
- // 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 point objects), the function immediately returns. If splitting is
- // possible, a SplitPoint object is initialized with all the data that must be
- // copied to the helper threads and we tell our helper threads that they have
- // been assigned work. This will cause them to instantly leave their idle loops and
- // call search().When all threads have returned from search() then split() returns.
-
- template <bool Fake>
- 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_thread_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.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.slaves[i] = 0;
-
- 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 (thread_is_available(i, master))
- {
- threads[i].state = THREAD_BOOKED;
- threads[i].splitPoint = &splitPoint;
- splitPoint.slaves[i] = 1;
- 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.slaves[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);
}
return *this;
}
+ void RootMoveList::init(Position& pos, Move searchMoves[]) {
+
+ MoveStack mlist[MAX_MOVES];
+ Move* sm;
+
+ clear();
+ bestMoveChanges = 0;
+
+ // Generate all legal moves and add them to RootMoveList
+ MoveStack* last = generate<MV_LEGAL>(pos, mlist);
+ for (MoveStack* cur = mlist; cur != last; cur++)
+ {
+ // If we have a searchMoves[] list then verify cur->move
+ // is in the list before to add it.
+ for (sm = searchMoves; *sm && *sm != cur->move; sm++) {}
+
+ if (searchMoves[0] && *sm != cur->move)
+ continue;
+
+ RootMove rm;
+ rm.pv[0] = cur->move;
+ rm.pv[1] = MOVE_NONE;
+ rm.pv_score = -VALUE_INFINITE;
+ push_back(rm);
+ }
+ }
+
// extract_pv_from_tt() builds a PV by adding moves from the transposition table.
// We consider also failing high nodes and not only VALUE_TYPE_EXACT nodes. This
// allow to always have a ponder move even when we fail high at root and also a
return s.str();
}
+} // namespace
- void RootMoveList::init(Position& pos, Move searchMoves[]) {
- MoveStack mlist[MAX_MOVES];
- Move* sm;
+// ThreadsManager::idle_loop() is where the threads are parked when they have no work
+// to do. The parameter 'sp', if non-NULL, is a pointer to an active SplitPoint
+// object for which the current thread is the master.
- clear();
- bestMoveChanges = 0;
+void ThreadsManager::idle_loop(int threadID, SplitPoint* sp) {
- // Generate all legal moves and add them to RootMoveList
- MoveStack* last = generate<MV_LEGAL>(pos, mlist);
- for (MoveStack* cur = mlist; cur != last; cur++)
- {
- // If we have a searchMoves[] list then verify cur->move
- // is in the list before to add it.
- for (sm = searchMoves; *sm && *sm != cur->move; sm++) {}
+ assert(threadID >= 0 && threadID < MAX_THREADS);
- if (searchMoves[0] && *sm != cur->move)
- continue;
+ int i;
+ bool allFinished;
- RootMove rm;
- rm.pv[0] = cur->move;
- rm.pv[1] = MOVE_NONE;
- rm.pv_score = -VALUE_INFINITE;
- push_back(rm);
- }
- }
+ while (true)
+ {
+ // Slave threads can exit as soon as AllThreadsShouldExit raises,
+ // master should exit as last one.
+ if (allThreadsShouldExit)
+ {
+ assert(!sp);
+ threads[threadID].state = THREAD_TERMINATED;
+ return;
+ }
+ // If we are not thinking, wait for a condition to be signaled
+ // instead of wasting CPU time polling for work.
+ while ( threadID >= activeThreads
+ || threads[threadID].state == THREAD_INITIALIZING
+ || (useSleepingThreads && threads[threadID].state == THREAD_AVAILABLE))
+ {
+ assert(!sp || useSleepingThreads);
+ assert(threadID != 0 || useSleepingThreads);
- // When playing with strength handicap choose best move among the MultiPV set
- // using a statistical rule dependent on SkillLevel. Idea by Heinz van Saanen.
- void do_skill_level(Move* best, Move* ponder) {
+ if (threads[threadID].state == THREAD_INITIALIZING)
+ threads[threadID].state = THREAD_AVAILABLE;
- assert(MultiPV > 1);
+ // Grab the lock to avoid races with Thread::wake_up()
+ lock_grab(&threads[threadID].sleepLock);
- // Rml list is already sorted by pv_score in descending order
- int s;
- int max_s = -VALUE_INFINITE;
- int size = Min(MultiPV, (int)Rml.size());
- int max = Rml[0].pv_score;
- int var = Min(max - Rml[size - 1].pv_score, PawnValueMidgame);
- int wk = 120 - 2 * SkillLevel;
+ // If we are master and all slaves have finished do not go to sleep
+ for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
+ allFinished = (i == activeThreads);
- // PRNG sequence should be non deterministic
- for (int i = abs(get_system_time() % 50); i > 0; i--)
- RK.rand<unsigned>();
+ if (allFinished || allThreadsShouldExit)
+ {
+ lock_release(&threads[threadID].sleepLock);
+ break;
+ }
- // Choose best move. For each move's score we add two terms both dependent
- // on wk, one deterministic and bigger for weaker moves, and one random,
- // then we choose the move with the resulting highest score.
- for (int i = 0; i < size; i++)
- {
- s = Rml[i].pv_score;
+ // Do sleep here after retesting sleep conditions
+ if (threadID >= activeThreads || threads[threadID].state == THREAD_AVAILABLE)
+ cond_wait(&threads[threadID].sleepCond, &threads[threadID].sleepLock);
- // Don't allow crazy blunders even at very low skills
- if (i > 0 && Rml[i-1].pv_score > s + EasyMoveMargin)
- break;
+ lock_release(&threads[threadID].sleepLock);
+ }
- // This is our magical formula
- s += ((max - s) * wk + var * (RK.rand<unsigned>() % wk)) / 128;
+ // If this thread has been assigned work, launch a search
+ if (threads[threadID].state == THREAD_WORKISWAITING)
+ {
+ assert(!allThreadsShouldExit);
- if (s > max_s)
- {
- max_s = s;
- *best = Rml[i].pv[0];
- *ponder = Rml[i].pv[1];
- }
- }
- }
+ threads[threadID].state = THREAD_SEARCHING;
-} // namespace
+ // Copy split point position and search stack and call search()
+ // with SplitPoint template parameter set to true.
+ SearchStack ss[PLY_MAX_PLUS_2];
+ SplitPoint* tsp = threads[threadID].splitPoint;
+ Position pos(*tsp->pos, threadID);
+
+ memcpy(ss, tsp->ss - 1, 4 * sizeof(SearchStack));
+ (ss+1)->sp = tsp;
+
+ if (tsp->pvNode)
+ search<PV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+ else
+ search<NonPV, true, false>(pos, ss+1, tsp->alpha, tsp->beta, tsp->depth);
+
+ assert(threads[threadID].state == THREAD_SEARCHING);
+
+ threads[threadID].state = THREAD_AVAILABLE;
+
+ // Wake up master thread so to allow it to return from the idle loop in
+ // case we are the last slave of the split point.
+ if ( useSleepingThreads
+ && threadID != tsp->master
+ && threads[tsp->master].state == THREAD_AVAILABLE)
+ threads[tsp->master].wake_up();
+ }
+
+ // If this thread is the master of a split point and all slaves have
+ // finished their work at this split point, return from the idle loop.
+ for (i = 0; sp && i < activeThreads && !sp->slaves[i]; i++) {}
+ allFinished = (i == activeThreads);
+
+ if (allFinished)
+ {
+ // Because sp->slaves[] is reset under lock protection,
+ // be sure sp->lock has been released before to return.
+ lock_grab(&(sp->lock));
+ lock_release(&(sp->lock));
+
+ // 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(threads[threadID].state == THREAD_AVAILABLE);
+
+ threads[threadID].state = THREAD_SEARCHING;
+ return;
+ }
+ }
+}
projects / stockfish / blobdiff