]> git.sesse.net Git - stockfish/blobdiff - src/thread.cpp
Merge remote-tracking branch 'upstream/master'
[stockfish] / src / thread.cpp
index c680393e27752135aa95ea76943233bc539fb83e..de8de87d8a2b9d94f6f57b9876d658f459abfbc0 100644 (file)
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include <cassert>
+#include "thread.h"
 
-#include <algorithm> // For std::count
+#include <algorithm>
+#include <cassert>
+#include <cmath>
+#include <cstdlib>
+#include <deque>
+#include <initializer_list>
+#include <map>
+#include <memory>
+#include <utility>
+
+#include "evaluate.h"
+#include "misc.h"
 #include "movegen.h"
 #include "search.h"
-#include "thread.h"
-#include "uci.h"
 #include "syzygy/tbprobe.h"
 #include "tt.h"
+#include "uci.h"
 
 namespace Stockfish {
 
-ThreadPool Threads; // Global object
-
+ThreadPool Threads;  // Global object
 
-/// Thread constructor launches the thread and waits until it goes to sleep
-/// in idle_loop(). Note that 'searching' and 'exit' should be already set.
 
-Thread::Thread(size_t n) : idx(n), stdThread(&Thread::idle_loop, this) {
+// Constructor launches the thread and waits until it goes to sleep
+// in idle_loop(). Note that 'searching' and 'exit' should be already set.
+Thread::Thread(size_t n) :
+    idx(n),
+    stdThread(&Thread::idle_loop, this) {
 
-  wait_for_search_finished();
+    wait_for_search_finished();
 }
 
 
-/// Thread destructor wakes up the thread in idle_loop() and waits
-/// for its termination. Thread should be already waiting.
-
+// Destructor wakes up the thread in idle_loop() and waits
+// for its termination. Thread should be already waiting.
 Thread::~Thread() {
 
-  assert(!searching);
+    assert(!searching);
 
-  exit = true;
-  start_searching();
-  stdThread.join();
+    exit = true;
+    start_searching();
+    stdThread.join();
 }
 
 
-/// Thread::clear() reset histories, usually before a new game
-
+// Reset histories, usually before a new game
 void Thread::clear() {
 
-  counterMoves.fill(MOVE_NONE);
-  mainHistory.fill(0);
-  captureHistory.fill(0);
+    counterMoves.fill(MOVE_NONE);
+    mainHistory.fill(0);
+    captureHistory.fill(0);
+    pawnHistory.fill(0);
 
-  for (bool inCheck : { false, true })
-      for (StatsType c : { NoCaptures, Captures })
-          for (auto& to : continuationHistory[inCheck][c])
-              for (auto& h : to)
-                  h->fill(-71);
+    for (bool inCheck : {false, true})
+        for (StatsType c : {NoCaptures, Captures})
+            for (auto& to : continuationHistory[inCheck][c])
+                for (auto& h : to)
+                    h->fill(-71);
 }
 
 
-/// Thread::start_searching() wakes up the thread that will start the search
-
+// Wakes up the thread that will start the search
 void Thread::start_searching() {
-  mutex.lock();
-  searching = true;
-  mutex.unlock(); // Unlock before notifying saves a few CPU-cycles
-  cv.notify_one(); // Wake up the thread in idle_loop()
+    mutex.lock();
+    searching = true;
+    mutex.unlock();   // Unlock before notifying saves a few CPU-cycles
+    cv.notify_one();  // Wake up the thread in idle_loop()
 }
 
 
-/// Thread::wait_for_search_finished() blocks on the condition variable
-/// until the thread has finished searching.
-
+// Blocks on the condition variable
+// until the thread has finished searching.
 void Thread::wait_for_search_finished() {
 
-  std::unique_lock<std::mutex> lk(mutex);
-  cv.wait(lk, [&]{ return !searching; });
+    std::unique_lock<std::mutex> lk(mutex);
+    cv.wait(lk, [&] { return !searching; });
 }
 
 
-/// Thread::idle_loop() is where the thread is parked, blocked on the
-/// condition variable, when it has no work to do.
+// Thread gets parked here, blocked on the
+// condition variable, when it has no work to do.
 
 void Thread::idle_loop() {
 
-  // If OS already scheduled us on a different group than 0 then don't overwrite
-  // the choice, eventually we are one of many one-threaded processes running on
-  // some Windows NUMA hardware, for instance in fishtest. To make it simple,
-  // just check if running threads are below a threshold, in this case all this
-  // NUMA machinery is not needed.
-  if (Options["Threads"] > 8)
-      WinProcGroup::bindThisThread(idx);
+    // If OS already scheduled us on a different group than 0 then don't overwrite
+    // the choice, eventually we are one of many one-threaded processes running on
+    // some Windows NUMA hardware, for instance in fishtest. To make it simple,
+    // just check if running threads are below a threshold, in this case, all this
+    // NUMA machinery is not needed.
+    if (Options["Threads"] > 8)
+        WinProcGroup::bindThisThread(idx);
 
-  while (true)
-  {
-      std::unique_lock<std::mutex> lk(mutex);
-      searching = false;
-      cv.notify_one(); // Wake up anyone waiting for search finished
-      cv.wait(lk, [&]{ return searching; });
+    while (true)
+    {
+        std::unique_lock<std::mutex> lk(mutex);
+        searching = false;
+        cv.notify_one();  // Wake up anyone waiting for search finished
+        cv.wait(lk, [&] { return searching; });
 
-      if (exit)
-          return;
+        if (exit)
+            return;
 
-      lk.unlock();
+        lk.unlock();
 
-      search();
-  }
+        search();
+    }
 }
 
-/// ThreadPool::set() creates/destroys threads to match the requested number.
-/// Created and launched threads will immediately go to sleep in idle_loop.
-/// Upon resizing, threads are recreated to allow for binding if necessary.
-
+// Creates/destroys threads to match the requested number.
+// Created and launched threads will immediately go to sleep in idle_loop.
+// Upon resizing, threads are recreated to allow for binding if necessary.
 void ThreadPool::set(size_t requested) {
 
-  if (threads.size() > 0)   // destroy any existing thread(s)
-  {
-      main()->wait_for_search_finished();
+    if (threads.size() > 0)  // destroy any existing thread(s)
+    {
+        main()->wait_for_search_finished();
 
-      while (threads.size() > 0)
-          delete threads.back(), threads.pop_back();
-  }
+        while (threads.size() > 0)
+            delete threads.back(), threads.pop_back();
+    }
 
-  if (requested > 0)   // create new thread(s)
-  {
-      threads.push_back(new MainThread(0));
+    if (requested > 0)  // create new thread(s)
+    {
+        threads.push_back(new MainThread(0));
 
-      while (threads.size() < requested)
-          threads.push_back(new Thread(threads.size()));
-      clear();
+        while (threads.size() < requested)
+            threads.push_back(new Thread(threads.size()));
+        clear();
 
-      // Reallocate the hash with the new threadpool size
-      TT.resize(size_t(Options["Hash"]));
+        // Reallocate the hash with the new threadpool size
+        TT.resize(size_t(Options["Hash"]));
 
-      // Init thread number dependent search params.
-      Search::init();
-  }
+        // Init thread number dependent search params.
+        Search::init();
+    }
 }
 
 
-/// ThreadPool::clear() sets threadPool data to initial values
-
+// Sets threadPool data to initial values
 void ThreadPool::clear() {
 
-  for (Thread* th : threads)
-      th->clear();
+    for (Thread* th : threads)
+        th->clear();
 
-  main()->callsCnt = 0;
-  main()->bestPreviousScore = VALUE_INFINITE;
-  main()->bestPreviousAverageScore = VALUE_INFINITE;
-  main()->previousTimeReduction = 1.0;
+    main()->callsCnt                 = 0;
+    main()->bestPreviousScore        = VALUE_INFINITE;
+    main()->bestPreviousAverageScore = VALUE_INFINITE;
+    main()->previousTimeReduction    = 1.0;
 }
 
 
-/// ThreadPool::start_thinking() wakes up main thread waiting in idle_loop() and
-/// returns immediately. Main thread will wake up other threads and start the search.
+// Wakes up main thread waiting in idle_loop() and
+// returns immediately. Main thread will wake up other threads and start the search.
+void ThreadPool::start_thinking(Position&                 pos,
+                                StateListPtr&             states,
+                                const Search::LimitsType& limits,
+                                bool                      ponderMode) {
 
-void ThreadPool::start_thinking(Position& pos, StateListPtr& states,
-                                const Search::LimitsType& limits, bool ponderMode) {
+    main()->wait_for_search_finished();
 
-  main()->wait_for_search_finished();
+    main()->stopOnPonderhit = stop = false;
+    increaseDepth                  = true;
+    main()->ponder                 = ponderMode;
+    Search::Limits                 = limits;
+    Search::RootMoves rootMoves;
 
-  main()->stopOnPonderhit = stop = false;
-  increaseDepth = true;
-  main()->ponder = ponderMode;
-  Search::Limits = limits;
-  Search::RootMoves rootMoves;
+    for (const auto& m : MoveList<LEGAL>(pos))
+        if (limits.searchmoves.empty()
+            || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m))
+            rootMoves.emplace_back(m);
 
-  for (const auto& m : MoveList<LEGAL>(pos))
-      if (   limits.searchmoves.empty()
-          || std::count(limits.searchmoves.begin(), limits.searchmoves.end(), m))
-          rootMoves.emplace_back(m);
+    if (!rootMoves.empty())
+        Tablebases::rank_root_moves(pos, rootMoves);
 
-  if (!rootMoves.empty())
-      Tablebases::rank_root_moves(pos, rootMoves);
+    // After ownership transfer 'states' becomes empty, so if we stop the search
+    // and call 'go' again without setting a new position states.get() == nullptr.
+    assert(states.get() || setupStates.get());
 
-  // After ownership transfer 'states' becomes empty, so if we stop the search
-  // and call 'go' again without setting a new position states.get() == nullptr.
-  assert(states.get() || setupStates.get());
+    if (states.get())
+        setupStates = std::move(states);  // Ownership transfer, states is now empty
 
-  if (states.get())
-      setupStates = std::move(states); // Ownership transfer, states is now empty
-
-  // We use Position::set() to set root position across threads. But there are
-  // some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
-  // be deduced from a fen string, so set() clears them and they are set from
-  // setupStates->back() later. The rootState is per thread, earlier states are shared
-  // since they are read-only.
-  for (Thread* th : threads)
-  {
-      th->nodes = th->tbHits = th->nmpMinPly = th->bestMoveChanges = 0;
-      th->rootDepth = th->completedDepth = 0;
-      th->rootMoves = rootMoves;
-      th->rootPos.set(pos.fen(), pos.is_chess960(), &th->rootState, th);
-      th->rootState = setupStates->back();
-  }
-
-  main()->start_searching();
+    // We use Position::set() to set root position across threads. But there are
+    // some StateInfo fields (previous, pliesFromNull, capturedPiece) that cannot
+    // be deduced from a fen string, so set() clears them and they are set from
+    // setupStates->back() later. The rootState is per thread, earlier states are shared
+    // since they are read-only.
+    for (Thread* th : threads)
+    {
+        th->nodes = th->tbHits = th->nmpMinPly = th->bestMoveChanges = 0;
+        th->rootDepth = th->completedDepth = 0;
+        th->rootMoves                      = rootMoves;
+        th->rootPos.set(pos.fen(), pos.is_chess960(), &th->rootState, th);
+        th->rootState      = setupStates->back();
+        th->rootSimpleEval = Eval::simple_eval(pos, pos.side_to_move());
+    }
+
+    main()->start_searching();
 }
 
 Thread* ThreadPool::get_best_thread() const {
 
-    Thread* bestThread = threads.front();
+    Thread*                 bestThread = threads.front();
     std::map<Move, int64_t> votes;
-    Value minScore = VALUE_NONE;
+    Value                   minScore = VALUE_NONE;
 
-    // Find minimum score of all threads
-    for (Thread* th: threads)
+    // Find the minimum score of all threads
+    for (Thread* th : threads)
         minScore = std::min(minScore, th->rootMoves[0].score);
 
     // Vote according to score and depth, and select the best thread
     auto thread_value = [minScore](Thread* th) {
-            return (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
-        };
+        return (th->rootMoves[0].score - minScore + 14) * int(th->completedDepth);
+    };
 
     for (Thread* th : threads)
         votes[th->rootMoves[0].pv[0]] += thread_value(th);
 
     for (Thread* th : threads)
-        if (abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
+        if (std::abs(bestThread->rootMoves[0].score) >= VALUE_TB_WIN_IN_MAX_PLY)
         {
             // Make sure we pick the shortest mate / TB conversion or stave off mate the longest
             if (th->rootMoves[0].score > bestThread->rootMoves[0].score)
                 bestThread = th;
         }
-        else if (   th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
-                 || (   th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
-                     && (   votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]
-                         || (   votes[th->rootMoves[0].pv[0]] == votes[bestThread->rootMoves[0].pv[0]]
-                             &&   thread_value(th) * int(th->rootMoves[0].pv.size() > 2)
-                                > thread_value(bestThread) * int(bestThread->rootMoves[0].pv.size() > 2)))))
+        else if (th->rootMoves[0].score >= VALUE_TB_WIN_IN_MAX_PLY
+                 || (th->rootMoves[0].score > VALUE_TB_LOSS_IN_MAX_PLY
+                     && (votes[th->rootMoves[0].pv[0]] > votes[bestThread->rootMoves[0].pv[0]]
+                         || (votes[th->rootMoves[0].pv[0]] == votes[bestThread->rootMoves[0].pv[0]]
+                             && thread_value(th) * int(th->rootMoves[0].pv.size() > 2)
+                                  > thread_value(bestThread)
+                                      * int(bestThread->rootMoves[0].pv.size() > 2)))))
             bestThread = th;
 
     return bestThread;
 }
 
 
-/// Start non-main threads
+// Start non-main threads
 
 void ThreadPool::start_searching() {
 
@@ -256,7 +265,7 @@ void ThreadPool::start_searching() {
 }
 
 
-/// Wait for non-main threads
+// Wait for non-main threads
 
 void ThreadPool::wait_for_search_finished() const {
 
@@ -265,4 +274,4 @@ void ThreadPool::wait_for_search_finished() const {
             th->wait_for_search_finished();
 }
 
-} // namespace Stockfish
+}  // namespace Stockfish