Use fast SRWLOCK locks under Windows

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index b38b45058ee474d7c9445d6310248436999b4114..b303d31f521e61a6bf61f690cc9b3de3391401fd 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -83,7 +83,6 @@ namespace {
     bool thread_is_available(int slave, int master) const;
     bool thread_should_stop(int threadID) const;
     void wake_sleeping_thread(int threadID);
-    void put_threads_to_sleep();
     void idle_loop(int threadID, SplitPoint* sp);
 
     template <bool Fake>
@@ -94,17 +93,10 @@ namespace {
     friend void poll();
 
     int ActiveThreads;
-    volatile bool AllThreadsShouldExit, AllThreadsShouldSleep;
+    volatile bool AllThreadsShouldExit;
     Thread threads[MAX_THREADS];
-
     Lock MPLock, WaitLock;
-
-#if !defined(_MSC_VER)
-    pthread_cond_t WaitCond[MAX_THREADS];
-#else
-    HANDLE SitIdleEvent[MAX_THREADS];
-#endif
-
+    WaitCondition WaitCond[MAX_THREADS];
   };
 
 
@@ -508,7 +500,8 @@ bool think(const Position& pos, bool infinite, bool ponder, int time[], int incr
   if (UseLogFile)
       LogFile.close();
 
-  ThreadsMgr.put_threads_to_sleep();
+  // This makes all the threads to go to sleep
+  ThreadsMgr.set_active_threads(1);
 
   return !Quit;
 }
@@ -2231,30 +2224,28 @@ split_point_start: // At split points actual search starts from here
 
         // If we are not thinking, wait for a condition to be signaled
         // instead of wasting CPU time polling for work.
-        while (AllThreadsShouldSleep || threadID >= ActiveThreads)
+        while (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
         {
             assert(!sp);
             assert(threadID != 0);
-            threads[threadID].state = THREAD_SLEEPING;
 
-#if !defined(_MSC_VER)
+            if (AllThreadsShouldExit)
+                break;
+
+            threads[threadID].state = THREAD_AVAILABLE;
+
             lock_grab(&WaitLock);
-            if (AllThreadsShouldSleep || threadID >= ActiveThreads)
-                pthread_cond_wait(&WaitCond[threadID], &WaitLock);
+
+            if (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
+                cond_wait(&WaitCond[threadID], &WaitLock);
+
             lock_release(&WaitLock);
-#else
-            WaitForSingleObject(SitIdleEvent[threadID], INFINITE);
-#endif
         }
 
-        // If thread has just woken up, mark it as available
-        if (threads[threadID].state == THREAD_SLEEPING)
-            threads[threadID].state = THREAD_AVAILABLE;
-
         // If this thread has been assigned work, launch a search
         if (threads[threadID].state == THREAD_WORKISWAITING)
         {
-            assert(!AllThreadsShouldExit && !AllThreadsShouldSleep);
+            assert(!AllThreadsShouldExit);
 
             threads[threadID].state = THREAD_SEARCHING;
 
@@ -2306,20 +2297,12 @@ split_point_start: // At split points actual search starts from here
     volatile int i;
     bool ok;
 
-#if !defined(_MSC_VER)
-    pthread_t pthread[1];
-#endif
-
     // Initialize global locks
     lock_init(&MPLock);
     lock_init(&WaitLock);
 
     for (i = 0; i < MAX_THREADS; i++)
-#if !defined(_MSC_VER)
-        pthread_cond_init(&WaitCond[i], NULL);
-#else
-        SitIdleEvent[i] = CreateEvent(0, FALSE, FALSE, 0);
-#endif
+        cond_init(&WaitCond[i]);
 
     // Initialize splitPoints[] locks
     for (i = 0; i < MAX_THREADS; i++)
@@ -2329,20 +2312,20 @@ split_point_start: // At split points actual search starts from here
     // Will be set just before program exits to properly end the threads
     AllThreadsShouldExit = false;
 
-    // Threads will be put to sleep as soon as created
-    AllThreadsShouldSleep = true;
-
-    // All threads except the main thread should be initialized to THREAD_AVAILABLE
+    // Threads will be put all threads to sleep as soon as created
     ActiveThreads = 1;
+
+    // All threads except the main thread should be initialized to THREAD_INITIALIZING
     threads[0].state = THREAD_SEARCHING;
     for (i = 1; i < MAX_THREADS; i++)
-        threads[i].state = THREAD_AVAILABLE;
+        threads[i].state = THREAD_INITIALIZING;
 
     // Launch the helper threads
     for (i = 1; i < MAX_THREADS; i++)
     {
 
 #if !defined(_MSC_VER)
+        pthread_t pthread[1];
         ok = (pthread_create(pthread, NULL, init_thread, (void*)(&i)) == 0);
 #else
         ok = (CreateThread(NULL, 0, init_thread, (LPVOID)(&i), 0, NULL) != NULL);
@@ -2355,7 +2338,7 @@ split_point_start: // At split points actual search starts from here
         }
 
         // Wait until the thread has finished launching and is gone to sleep
-        while (threads[i].state != THREAD_SLEEPING) {}
+        while (threads[i].state == THREAD_INITIALIZING) {}
     }
   }
 
@@ -2366,7 +2349,6 @@ split_point_start: // At split points actual search starts from here
   void ThreadsManager::exit_threads() {
 
     AllThreadsShouldExit = true; // Let the woken up threads to exit idle_loop()
-    ActiveThreads = MAX_THREADS; // Avoid any woken up thread comes back to sleep
 
     // Wake up all the threads and waits for termination
     for (int i = 1; i < MAX_THREADS; i++)
@@ -2382,6 +2364,10 @@ split_point_start: // At split points actual search starts from here
 
     lock_destroy(&WaitLock);
     lock_destroy(&MPLock);
+
+    // Now we can safely destroy the wait conditions
+    for (int i = 0; i < MAX_THREADS; i++)
+        cond_destroy(&WaitCond[i]);
   }
 
 
@@ -2569,33 +2555,12 @@ split_point_start: // At split points actual search starts from here
 
   void ThreadsManager::wake_sleeping_thread(int threadID) {
 
-    assert(threadID > 0);
-    assert(threads[threadID].state == THREAD_SLEEPING);
-
-    AllThreadsShouldSleep = false; // Avoid the woken up thread comes back to sleep
-
-#if !defined(_MSC_VER)
-        pthread_mutex_lock(&WaitLock);
-        pthread_cond_signal(&WaitCond[threadID]);
-        pthread_mutex_unlock(&WaitLock);
-#else
-        SetEvent(SitIdleEvent[threadID]);
-#endif
+     lock_grab(&WaitLock);
+     cond_signal(&WaitCond[threadID]);
+     lock_release(&WaitLock);
   }
 
 
-  // put_threads_to_sleep() makes all the threads go to sleep just before
-  // to leave think(), at the end of the search. Threads should have already
-  // finished the job and should be idle.
-
-  void ThreadsManager::put_threads_to_sleep() {
-
-    assert(!AllThreadsShouldSleep || ActiveThreads == 1);
-
-    // This makes the threads to go to sleep
-    AllThreadsShouldSleep = true;
-  }
-
   /// The RootMoveList class
 
   // RootMoveList c'tor