Retire AllThreadsShouldSleep flag

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index b38b45058ee474d7c9445d6310248436999b4114..861eaacabef8c90f190b5ee96c9ba9a8db8fc50b 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -94,17 +94,10 @@ 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];
   };
 
 
@@ -2231,7 +2224,7 @@ 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)
         {
             assert(!sp);
             assert(threadID != 0);
@@ -2239,11 +2232,11 @@ split_point_start: // At split points actual search starts from here
 
 #if !defined(_MSC_VER)
             lock_grab(&WaitLock);
-            if (AllThreadsShouldSleep || threadID >= ActiveThreads)
+            if (threadID >= ActiveThreads)
                 pthread_cond_wait(&WaitCond[threadID], &WaitLock);
             lock_release(&WaitLock);
 #else
-            WaitForSingleObject(SitIdleEvent[threadID], INFINITE);
+            WaitForSingleObject(WaitCond[threadID], INFINITE);
 #endif
         }
 
@@ -2254,7 +2247,7 @@ split_point_start: // At split points actual search starts from here
         // 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;
 
@@ -2306,10 +2299,6 @@ 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);
@@ -2318,7 +2307,7 @@ split_point_start: // At split points actual search starts from here
 #if !defined(_MSC_VER)
         pthread_cond_init(&WaitCond[i], NULL);
 #else
-        SitIdleEvent[i] = CreateEvent(0, FALSE, FALSE, 0);
+        WaitCond[i] = CreateEvent(0, FALSE, FALSE, 0);
 #endif
 
     // Initialize splitPoints[] locks
@@ -2330,10 +2319,9 @@ split_point_start: // At split points actual search starts from here
     AllThreadsShouldExit = false;
 
     // Threads will be put to sleep as soon as created
-    AllThreadsShouldSleep = true;
+    ActiveThreads = 1;
 
     // All threads except the main thread should be initialized to THREAD_AVAILABLE
-    ActiveThreads = 1;
     threads[0].state = THREAD_SEARCHING;
     for (i = 1; i < MAX_THREADS; i++)
         threads[i].state = THREAD_AVAILABLE;
@@ -2343,6 +2331,7 @@ split_point_start: // At split points actual search starts from here
     {
 
 #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);
@@ -2382,6 +2371,10 @@ 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]);
   }
 
 
@@ -2572,14 +2565,12 @@ split_point_start: // At split points actual search starts from here
     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]);
+        SetEvent(WaitCond[threadID]);
 #endif
   }
 
@@ -2590,10 +2581,8 @@ split_point_start: // At split points actual search starts from here
 
   void ThreadsManager::put_threads_to_sleep() {
 
-    assert(!AllThreadsShouldSleep || ActiveThreads == 1);
-
     // This makes the threads to go to sleep
-    AllThreadsShouldSleep = true;
+    ActiveThreads = 1;
   }
 
   /// The RootMoveList class