Revert "Allow split point master to sleep (take 2)"

[stockfish] / src / search.cpp

diff --git a/src/search.cpp b/src/search.cpp
index 5a4b56ba45ae2383bed345969d93432db8442f98..2c91d7789c4bb5bef69a61b44ff94b6af6c2d432 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -59,6 +59,10 @@ namespace {
   // Used for debugging SMP code.
   const bool FakeSplit = false;
 
+  // Fast lookup table of sliding pieces indexed by Piece
+  const bool Slidings[18] = { 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1 };
+  inline bool piece_is_slider(Piece p) { return Slidings[p]; }
+
   // ThreadsManager class is used to handle all the threads related stuff in search,
   // init, starting, parking and, the most important, launching a slave thread at a
   // split point are what this class does. All the access to shared thread data is
@@ -259,7 +263,6 @@ namespace {
   // Multi-threads related variables
   Depth MinimumSplitDepth;
   int MaxThreadsPerSplitPoint;
-  bool UseSleepingMaster;
   ThreadsManager ThreadsMgr;
 
   // Node counters, used only by thread[0] but try to keep in different cache
@@ -452,7 +455,6 @@ bool think(Position& pos, bool infinite, bool ponder, int time[], int increment[
   MaxThreadsPerSplitPoint = Options["Maximum Number of Threads per Split Point"].value<int>();
   MultiPV                 = Options["MultiPV"].value<int>();
   UseLogFile              = Options["Use Search Log"].value<bool>();
-  UseSleepingMaster       = Options["Use Sleeping Master"].value<bool>();
 
   if (UseLogFile)
       LogFile.open(Options["Search Log Filename"].value<std::string>().c_str(), std::ios::out | std::ios::app);
@@ -1932,7 +1934,7 @@ split_point_start: // At split points actual search starts from here
     int t = current_search_time();
 
     //  Poll for input
-    if (Bioskey())
+    if (data_available())
     {
         // We are line oriented, don't read single chars
         std::string command;
@@ -2180,9 +2182,6 @@ split_point_start: // At split points actual search starts from here
 
     assert(threadID >= 0 && threadID < MAX_THREADS);
 
-    int i;
-    bool allFinished = false;
-
     while (true)
     {
         // Slave threads can exit as soon as AllThreadsShouldExit raises,
@@ -2198,23 +2197,23 @@ split_point_start: // At split points actual search starts from here
         // instead of wasting CPU time polling for work.
         while (   threadID >= ActiveThreads
                || threads[threadID].state == THREAD_INITIALIZING
-               || (threads[threadID].state == THREAD_AVAILABLE && (!sp || UseSleepingMaster)))
+               || (!sp && threads[threadID].state == THREAD_AVAILABLE))
         {
-            lock_grab(&MPLock);
+            assert(!sp);
+            assert(threadID != 0);
 
-            // Test with lock held to avoid races with wake_sleeping_thread()
-            for (i = 0; sp && i < ActiveThreads && !sp->slaves[i]; i++) {}
-            allFinished = (i == ActiveThreads);
+            if (AllThreadsShouldExit)
+                break;
 
-            // Retest sleep conditions under lock protection
-            if (   AllThreadsShouldExit
-                || allFinished
-                || !(   threadID >= ActiveThreads
-                     || threads[threadID].state == THREAD_INITIALIZING
-                     || (threads[threadID].state == THREAD_AVAILABLE && (!sp || UseSleepingMaster))))
+            lock_grab(&MPLock);
+
+            // Retest condition under lock protection
+            if (!(   threadID >= ActiveThreads
+                  || threads[threadID].state == THREAD_INITIALIZING
+                  || (!sp && threads[threadID].state == THREAD_AVAILABLE)))
             {
                 lock_release(&MPLock);
-                break;
+                continue;
             }
 
             // Put thread to sleep
@@ -2244,19 +2243,14 @@ split_point_start: // At split points actual search starts from here
             assert(threads[threadID].state == THREAD_SEARCHING);
 
             threads[threadID].state = THREAD_AVAILABLE;
-
-            // Wake up master thread so to allow it to return from the idle loop in
-            // case we are the last slave of the split point.
-            if (UseSleepingMaster && threadID != tsp->master && threads[tsp->master].state == THREAD_AVAILABLE)
-                wake_sleeping_thread(tsp->master);
         }
 
         // If this thread is the master of a split point and all slaves have
         // finished their work at this split point, return from the idle loop.
-        for (i = 0; sp && i < ActiveThreads && !sp->slaves[i]; i++) {}
-        allFinished = (i == ActiveThreads);
+        int i = 0;
+        for ( ; sp && i < ActiveThreads && !sp->slaves[i]; i++) {}
 
-        if (allFinished)
+        if (i == ActiveThreads)
         {
             // Because sp->slaves[] is reset under lock protection,
             // be sure sp->lock has been released before to return.
@@ -2320,7 +2314,7 @@ split_point_start: // At split points actual search starts from here
         if (!ok)
         {
             cout << "Failed to create thread number " << i << endl;
-            Application::exit_with_failure();
+            exit(EXIT_FAILURE);
         }
 
         // Wait until the thread has finished launching and is gone to sleep
@@ -2464,7 +2458,6 @@ split_point_start: // At split points actual search starts from here
 
     // Initialize the split point object
     splitPoint.parent = masterThread.splitPoint;
-    splitPoint.master = master;
     splitPoint.stopRequest = false;
     splitPoint.ply = ply;
     splitPoint.depth = depth;