Make the debug counters thread safe.

vondele · mstembera · commit e2be41442b20 · 2019-07-31T18:41:10.000-07:00
needed to use them in a threaded run.

No functional change.
diff --git a/src/misc.cpp b/src/misc.cpp
@@ -145,7 +145,7 @@ const string engine_info(bool to_uci) {
 
 
 /// Debug functions used mainly to collect run-time statistics
-static int64_t hits[2], means[2];
+static std::atomic<int64_t> hits[2], means[2];
 
 void dbg_hit_on(bool b) { ++hits[0]; if (b) ++hits[1]; }
 void dbg_hit_on(bool c, bool b) { if (c) dbg_hit_on(b); }
