debug required count

Signed-off-by: James Cherry <cherry@parallaxsw.com>

include/sta/Debug.hh

@@ -49,11 +49,12 @@ public:
   int statsLevel() const { return stats_level_; }
   void reportLine(const char *what,
                   const char *fmt,
-                  ...) const
+                  ...)
     __attribute__((format (printf, 3, 4)));
 
 protected:
   Report *report_;
+  std::mutex buffer_lock_;
   bool debug_on_;
   DebugMap *debug_map_;
   int stats_level_;

search/Bfs.cc

@@ -217,6 +217,7 @@ BfsIterator::visitParallel(Level to_level,
           }
 	  visitor->levelFinished();
 	  level_vertices.clear();
+          visit_count += vertex_count;
 	}
       }
       for (VertexVisitor *visitor : visitors)

util/Debug.cc

@@ -114,10 +114,11 @@ Debug::setLevel(const char *what,
 void
 Debug::reportLine(const char *what,
                   const char *fmt,
-                  ...) const
+                  ...)
 {
   va_list args;
   va_start(args, fmt);
+  std::unique_lock<std::mutex> lock(buffer_lock_);
   report_->printToBuffer("%s", what);
   report_->printToBufferAppend(": ");
   report_->printToBufferAppend(fmt, args);