Revert sleeping threads
authorMarco Costalba <mcostalba@gmail.com>
Fri, 19 Nov 2010 06:59:51 +0000 (07:59 +0100)
committerMarco Costalba <mcostalba@gmail.com>
Sat, 27 Nov 2010 20:26:00 +0000 (21:26 +0100)
Revert 141caf1d5b64 + c59efc53c9

Signed-off-by: Marco Costalba <mcostalba@gmail.com>
src/search.cpp

index 2c91d7789c4bb5bef69a61b44ff94b6af6c2d432..4bacbef01b6c813a9cd2ec6b1354e3b20b32b909 100644 (file)
@@ -94,7 +94,7 @@ namespace {
     int ActiveThreads;
     volatile bool AllThreadsShouldExit;
     Thread threads[MAX_THREADS];
-    Lock MPLock;
+    Lock MPLock, WaitLock;
     WaitCondition WaitCond[MAX_THREADS];
   };
 
@@ -469,6 +469,10 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[
       init_eval(ThreadsMgr.active_threads());
   }
 
+  // Wake up needed threads
+  for (int i = 1; i < newActiveThreads; i++)
+      ThreadsMgr.wake_sleeping_thread(i);
+
   // Set thinking time
   int myTime = time[pos.side_to_move()];
   int myIncrement = increment[pos.side_to_move()];
@@ -501,6 +505,9 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[
   if (UseLogFile)
       LogFile.close();
 
+  // This makes all the threads to go to sleep
+  ThreadsMgr.set_active_threads(1);
+
   return !Quit;
 }
 
@@ -2195,9 +2202,7 @@ 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 (   threadID >= ActiveThreads
-               || threads[threadID].state == THREAD_INITIALIZING
-               || (!sp && threads[threadID].state == THREAD_AVAILABLE))
+        while (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
         {
             assert(!sp);
             assert(threadID != 0);
@@ -2205,21 +2210,14 @@ split_point_start: // At split points actual search starts from here
             if (AllThreadsShouldExit)
                 break;
 
-            lock_grab(&MPLock);
+            threads[threadID].state = THREAD_AVAILABLE;
 
-            // Retest condition under lock protection
-            if (!(   threadID >= ActiveThreads
-                  || threads[threadID].state == THREAD_INITIALIZING
-                  || (!sp && threads[threadID].state == THREAD_AVAILABLE)))
-            {
-                lock_release(&MPLock);
-                continue;
-            }
+            lock_grab(&WaitLock);
 
-            // Put thread to sleep
-            threads[threadID].state = THREAD_AVAILABLE;
-            cond_wait(&WaitCond[threadID], &MPLock);
-            lock_release(&MPLock);
+            if (threadID >= ActiveThreads || threads[threadID].state == THREAD_INITIALIZING)
+                cond_wait(&WaitCond[threadID], &WaitLock);
+
+            lock_release(&WaitLock);
         }
 
         // If this thread has been assigned work, launch a search
@@ -2279,6 +2277,7 @@ split_point_start: // At split points actual search starts from here
 
     // Initialize global locks
     lock_init(&MPLock);
+    lock_init(&WaitLock);
 
     for (i = 0; i < MAX_THREADS; i++)
         cond_init(&WaitCond[i]);
@@ -2342,6 +2341,7 @@ split_point_start: // At split points actual search starts from here
         for (int j = 0; j < MAX_ACTIVE_SPLIT_POINTS; j++)
             lock_destroy(&(threads[i].splitPoints[j].lock));
 
+    lock_destroy(&WaitLock);
     lock_destroy(&MPLock);
 
     // Now we can safely destroy the wait conditions
@@ -2507,8 +2507,6 @@ split_point_start: // At split points actual search starts from here
             assert(i == master || threads[i].state == THREAD_BOOKED);
 
             threads[i].state = THREAD_WORKISWAITING; // This makes the slave to exit from idle_loop()
-            if (i != master)
-                wake_sleeping_thread(i);
         }
 
     // Everything is set up. The master thread enters the idle loop, from
@@ -2537,9 +2535,9 @@ split_point_start: // At split points actual search starts from here
 
   void ThreadsManager::wake_sleeping_thread(int threadID) {
 
-     lock_grab(&MPLock);
+     lock_grab(&WaitLock);
      cond_signal(&WaitCond[threadID]);
-     lock_release(&MPLock);
+     lock_release(&WaitLock);
   }