X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=536f22c1194cf6912eb578f550cf1d298d21d959;hp=d845fdf2e4183f2fdaa10bb656b66d1ab6439749;hb=6809b57cfc47321826f01253241afef8b4380612;hpb=83d8fe2d59bad718de70b00ac2c8fddfadda76b5

diff --git a/src/thread.cpp b/src/thread.cpp
index d845fdf2..536f22c1 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -19,6 +19,7 @@
 
 #include <iostream>
 
+#include "search.h"
 #include "thread.h"
 #include "ucioption.h"
 
@@ -27,27 +28,26 @@ ThreadsManager Threads; // Global object definition
 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.
- // 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 thread) {
-
-    ((Thread*)thread)->idle_loop(NULL);
-    return 0;
-  }
-
 #else
-
   void* start_routine(void* thread) {
+#endif
 
-    ((Thread*)thread)->idle_loop(NULL);
-    return NULL;
-  }
+    if (((Thread*)thread)->threadID == 0)
+        ((Thread*)thread)->main_loop();
 
-#endif
+    else if (((Thread*)thread)->threadID == MAX_THREADS)
+        ((Thread*)thread)->timer_loop();
+    else
+        ((Thread*)thread)->idle_loop(NULL);
+
+    return 0;
+  }
 
 } }
 
@@ -124,7 +124,7 @@ void ThreadsManager::set_size(int cnt) {
 
   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
@@ -147,11 +147,14 @@ void ThreadsManager::set_size(int cnt) {
 
 void ThreadsManager::init() {
 
+  // 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);
@@ -161,15 +164,14 @@ void ThreadsManager::init() {
   }
 
   // Initialize main thread's associated data
-  threads[0].is_searching = true;
-  threads[0].threadID = 0;
-  set_size(1); // This makes all the threads but the main to go to sleep
+  threads[0].pawnTable.init();
+  threads[0].materialTable.init();
 
-  // Create and launch all the threads but the main that is already running,
-  // threads will go immediately to sleep.
-  for (int i = 1; i < MAX_THREADS; i++)
+  // Create and launch all the threads, threads will go immediately to sleep
+  for (int i = 0; i <= MAX_THREADS; i++)
   {
       threads[i].is_searching = false;
+      threads[i].do_sleep = true;
       threads[i].threadID = i;
 
 #if defined(_MSC_VER)
@@ -192,26 +194,18 @@ void ThreadsManager::init() {
 
 void ThreadsManager::exit() {
 
-  // Wake up all the slave threads at once. This is faster than "wake and wait"
-  // for each thread and avoids a rare crash once every 10K games under Linux.
-  for (int i = 1; i < MAX_THREADS; i++)
+  for (int i = 0; i <= MAX_THREADS; i++)
   {
       threads[i].do_terminate = true;
       threads[i].wake_up();
-  }
 
-  for (int i = 0; i < MAX_THREADS; i++)
-  {
-      if (i != 0)
-      {
-          // Wait for slave termination
+      // 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_join(threads[i].handle, NULL);
 #endif
-      }
 
       // Now we can safely destroy locks and wait conditions
       lock_destroy(&threads[i].sleepLock);
@@ -222,6 +216,7 @@ void ThreadsManager::exit() {
   }
 
   lock_destroy(&threadsLock);
+  cond_destroy(&sleepCond);
 }
 
 
@@ -240,6 +235,19 @@ bool ThreadsManager::available_slave_exists(int master) const {
 }
 
 
+// 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
@@ -253,7 +261,7 @@ template <bool Fake>
 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);
@@ -353,3 +361,129 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
 // 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::wait_end_of_search() blocks UI thread until main thread has
+// returned to sleep in main_loop(). It is needed becuase xboard sends immediately
+// new position to search after a "stop" due to ponder miss.
+
+void ThreadsManager::wait_end_of_search() {
+
+  Thread& main = threads[0];
+
+  lock_grab(&main.sleepLock);
+
+  while (!main.do_sleep)
+      cond_wait(&sleepCond, &main.sleepLock);
+
+  lock_release(&main.sleepLock);
+}
+
+
+// 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];
+
+  // Wait main thread has finished before to launch a new search
+  wait_end_of_search();
+
+  lock_grab(&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);
+}