Small split() cleanup

Unify start loop for master and slave threads. Also guarantee
that all the 'stop' flags are set to false before first slave
is started, should be no harm because only master thread can
reset 'stop' flag of slaves to true, so should be no race but
better safe then sorry.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

diff --git a/src/search.cpp b/src/search.cpp
index 96b8442343ca7f484459d452f3fdba9d56d5e860..d54c7ebd91fbcc5379974d7556bf14a86fff2f8a 100644 (file)
--- a/src/search.cpp
+++ b/src/search.cpp
@@ -2993,6 +2993,7 @@ namespace {
         splitPoint->slaves[i] = 0;
 
     Threads[master].idle = false;
+    Threads[master].stop = false;
     Threads[master].splitPoint = splitPoint;
 
     // Allocate available threads setting idle flag to false
@@ -3000,6 +3001,7 @@ namespace {
         if (thread_is_available(i, master))
         {
             Threads[i].idle = false;
+            Threads[i].stop = false;
             Threads[i].splitPoint = splitPoint;
             splitPoint->slaves[i] = 1;
             splitPoint->cpus++;
@@ -3010,22 +3012,14 @@ namespace {
     // We can release the lock because master and slave threads are already booked
     lock_release(&MPLock);
 
-    // Copy the tail of current search stack to the master thread
-    memcpy(splitPoint->sstack[master] + ply - 1, sstck + ply - 1, 3 * sizeof(SearchStack));
-
     // Tell the threads that they have work to do. This will make them leave
-    // their idle loop. Also copy search stack tail for each slave thread.
+    // their idle loop. But before copy search stack tail for each thread.
     for (int i = 0; i < ActiveThreads; i++)
-    {
-        if (splitPoint->slaves[i])
-            memcpy(splitPoint->sstack[i] + ply - 1, sstck + ply - 1, 3 * sizeof(SearchStack));
-
         if (i == master || splitPoint->slaves[i])
         {
-            Threads[i].stop = false;
+            memcpy(splitPoint->sstack[i] + ply - 1, sstck + ply - 1, 3 * sizeof(SearchStack));
             Threads[i].workIsWaiting = true; // This makes the slave to exit from idle_loop()
         }
-    }
 
     // Everything is set up. The master thread enters the idle loop, from
     // which it will instantly launch a search, because its workIsWaiting