X-Git-Url: https://git.sesse.net/?p=stockfish;a=blobdiff_plain;f=src%2Fthread.cpp;h=1f01537ffd2845ca311b509300eddedb5c9f899e;hp=f5bd50ea5cfa28ec157d3082ba440058c51189e5;hb=e5ffe9959c40a5ec6c4bca83a5a48070cae7fa5b;hpb=4a71c862702c05b3c56e902f4675fdf68041710b

diff --git a/src/thread.cpp b/src/thread.cpp
index f5bd50ea..1f01537f 100644
--- a/src/thread.cpp
+++ b/src/thread.cpp
@@ -27,7 +27,7 @@ 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() with the supplied threadID.
+ // 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.
 
@@ -35,7 +35,7 @@ namespace { extern "C" {
 
   DWORD WINAPI start_routine(LPVOID threadID) {
 
-    Threads.idle_loop(*(int*)threadID, NULL);
+    Threads[*(int*)threadID].idle_loop(NULL);
     return 0;
   }
 
@@ -43,7 +43,7 @@ namespace { extern "C" {
 
   void* start_routine(void* threadID) {
 
-    Threads.idle_loop(*(int*)threadID, NULL);
+    Threads[*(int*)threadID].idle_loop(NULL);
     return NULL;
   }
 
@@ -111,7 +111,35 @@ 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>();
+
+  set_size(Options["Threads"].value<int>());
+}
+
+
+// set_size() changes the number of active threads and raises do_sleep flag for
+// all the unused threads that will go immediately to sleep.
+
+void ThreadsManager::set_size(int cnt) {
+
+  assert(cnt > 0 && cnt <= MAX_THREADS);
+
+  activeThreads = cnt;
+
+  for (int i = 0; i < MAX_THREADS; i++)
+      if (i < activeThreads)
+      {
+          // Dynamically allocate pawn and material hash tables according to the
+          // number of active threads. This avoids preallocating memory for all
+          // possible threads if only few are used as, for instance, on mobile
+          // devices where memory is scarce and allocating for MAX_THREADS could
+          // even result in a crash.
+          threads[i].pawnTable.init();
+          threads[i].materialTable.init();
+
+          threads[i].do_sleep = false;
+      }
+      else
+          threads[i].do_sleep = true;
 }
 
 
@@ -120,21 +148,15 @@ void ThreadsManager::read_uci_options() {
 
 void ThreadsManager::init() {
 
-  int threadID[MAX_THREADS];
-
-  // 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;
+  // 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;
 
-  // Allocate pawn and material hash tables for main thread
-  init_hash_tables();
-
+  // Initialize threads lock, used when allocating slaves during splitting
   lock_init(&threadsLock);
 
-  // Initialize thread and split point locks
+  // Initialize sleep and split point locks
   for (int i = 0; i < MAX_THREADS; i++)
   {
       lock_init(&threads[i].sleepLock);
@@ -147,45 +169,47 @@ void ThreadsManager::init() {
   // Create and startup all the threads but the main that is already running
   for (int i = 1; i < MAX_THREADS; i++)
   {
-      threads[i].state = Thread::INITIALIZING;
-      threadID[i] = i;
+      threads[i].state = Thread::AVAILABLE;
+      threads[i].threadID = i;
 
 #if defined(_MSC_VER)
-      bool ok = (CreateThread(NULL, 0, start_routine, (LPVOID)&threadID[i], 0, NULL) != NULL);
+      threads[i].handle = CreateThread(NULL, 0, start_routine, (LPVOID)&threads[i].threadID, 0, NULL);
+      bool ok = (threads[i].handle != NULL);
 #else
-      pthread_t pthreadID;
-      bool ok = (pthread_create(&pthreadID, NULL, start_routine, (void*)&threadID[i]) == 0);
-      pthread_detach(pthreadID);
+      bool ok = (pthread_create(&threads[i].handle, NULL, start_routine, (void*)&threads[i].threadID) == 0);
 #endif
+
       if (!ok)
       {
           std::cout << "Failed to create thread number " << i << std::endl;
           ::exit(EXIT_FAILURE);
       }
-
-      // Wait until the thread has finished launching and is gone to sleep
-      while (threads[i].state == Thread::INITIALIZING) {}
   }
 }
 
 
-// exit() is called to cleanly exit the threads when the program finishes
+// exit() is called to cleanly terminate the threads when the program finishes
 
 void ThreadsManager::exit() {
 
-  // Force the woken up threads to exit idle_loop() and hence terminate
-  allThreadsShouldExit = true;
-
   for (int i = 0; i < MAX_THREADS; i++)
   {
-      // Wake up all the threads and waits for termination
+      // Wake up all the slave threads and wait for termination
       if (i != 0)
       {
+          threads[i].do_terminate = true;
           threads[i].wake_up();
-          while (threads[i].state != Thread::TERMINATED) {}
+
+#if defined(_MSC_VER)
+          WaitForSingleObject(threads[i].handle, 0);
+          CloseHandle(threads[i].handle);
+#else
+          pthread_join(threads[i].handle, NULL);
+          pthread_detach(threads[i].handle);
+#endif
       }
 
-      // Now we can safely destroy the locks and wait conditions
+      // Now we can safely destroy locks and wait conditions
       lock_destroy(&threads[i].sleepLock);
       cond_destroy(&threads[i].sleepCond);
 
@@ -197,22 +221,6 @@ void ThreadsManager::exit() {
 }
 
 
-// init_hash_tables() dynamically allocates pawn and material hash tables
-// according to the number of active threads. This avoids preallocating
-// memory for all possible threads if only few are used as, for instance,
-// on mobile devices where memory is scarce and allocating for MAX_THREADS
-// threads could even result in a crash.
-
-void ThreadsManager::init_hash_tables() {
-
-  for (int i = 0; i < activeThreads; i++)
-  {
-      threads[i].pawnTable.init();
-      threads[i].materialTable.init();
-  }
-}
-
-
 // available_slave_exists() tries to find an idle thread which is available as
 // a slave for the thread with threadID "master".
 
@@ -258,25 +266,25 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
       return bestValue;
 
   // Pick the next available split point object from the split point stack
-  SplitPoint& splitPoint = masterThread.splitPoints[masterThread.activeSplitPoints];
+  SplitPoint* sp = masterThread.splitPoints + masterThread.activeSplitPoints;
 
   // Initialize the split point object
-  splitPoint.parent = masterThread.splitPoint;
-  splitPoint.master = master;
-  splitPoint.is_betaCutoff = false;
-  splitPoint.depth = depth;
-  splitPoint.threatMove = threatMove;
-  splitPoint.alpha = alpha;
-  splitPoint.beta = beta;
-  splitPoint.nodeType = nodeType;
-  splitPoint.bestValue = bestValue;
-  splitPoint.mp = mp;
-  splitPoint.moveCount = moveCount;
-  splitPoint.pos = &pos;
-  splitPoint.nodes = 0;
-  splitPoint.ss = ss;
+  sp->parent = masterThread.splitPoint;
+  sp->master = master;
+  sp->is_betaCutoff = false;
+  sp->depth = depth;
+  sp->threatMove = threatMove;
+  sp->alpha = alpha;
+  sp->beta = beta;
+  sp->nodeType = nodeType;
+  sp->bestValue = bestValue;
+  sp->mp = mp;
+  sp->moveCount = moveCount;
+  sp->pos = &pos;
+  sp->nodes = 0;
+  sp->ss = ss;
   for (i = 0; i < activeThreads; i++)
-      splitPoint.is_slave[i] = false;
+      sp->is_slave[i] = false;
 
   // If we are here it means we are not available
   assert(masterThread.state == Thread::SEARCHING);
@@ -292,8 +300,8 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
       if (i != master && threads[i].is_available_to(master))
       {
           workersCnt++;
-          splitPoint.is_slave[i] = true;
-          threads[i].splitPoint = &splitPoint;
+          sp->is_slave[i] = true;
+          threads[i].splitPoint = sp;
 
           // This makes the slave to exit from idle_loop()
           threads[i].state = Thread::WORKISWAITING;
@@ -308,7 +316,7 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
   if (!Fake && workersCnt == 1)
       return bestValue;
 
-  masterThread.splitPoint = &splitPoint;
+  masterThread.splitPoint = sp;
   masterThread.activeSplitPoints++;
   masterThread.state = Thread::WORKISWAITING;
 
@@ -317,7 +325,11 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
   // 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);
+  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);
 
   // We have returned from the idle loop, which means that all threads are
   // finished. Note that changing state and decreasing activeSplitPoints is done
@@ -326,12 +338,13 @@ Value ThreadsManager::split(Position& pos, SearchStack* ss, Value alpha, Value b
 
   masterThread.state = Thread::SEARCHING;
   masterThread.activeSplitPoints--;
-  masterThread.splitPoint = splitPoint.parent;
 
   lock_release(&threadsLock);
 
-  pos.set_nodes_searched(pos.nodes_searched() + splitPoint.nodes);
-  return splitPoint.bestValue;
+  masterThread.splitPoint = sp->parent;
+  pos.set_nodes_searched(pos.nodes_searched() + sp->nodes);
+
+  return sp->bestValue;
 }
 
 // Explicit template instantiations