0026292: Visualization - Parallelize queue-based BVH builders (subclasses of BVH_QueueBuilder)

src/BVH/BVH_BuildQueue.hxx

@@ -0,0 +1,75 @@
+// Created on: 2015-05-28
+// Created by: Denis BOGOLEPOV
+// Copyright (c) 2015 OPEN CASCADE SAS
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _BVH_BuildQueue_Header
+#define _BVH_BuildQueue_Header
+
+#include <BVH_Builder.hxx>
+
+#include <Standard_Mutex.hxx>
+#include <NCollection_Sequence.hxx>
+
+//! Command-queue for parallel building of BVH nodes.
+class BVH_BuildQueue
+{
+  template <class T, int N> friend class BVH_QueueBuilder;
+
+public:
+
+  //! Creates new BVH build queue.
+  BVH_BuildQueue()
+  : myNbThreads (0)
+  {
+    //
+  }
+
+  //! Releases resources of BVH build queue.
+  ~BVH_BuildQueue()
+  {
+    //
+  }
+
+public:
+
+  //! Returns current size of BVH build queue.
+  Standard_EXPORT Standard_Integer Size();
+
+  //! Enqueues new work-item onto BVH build queue.
+  Standard_EXPORT void Enqueue (const Standard_Integer& theNode);
+
+  //! Fetches first work-item from BVH build queue.
+  Standard_EXPORT Standard_Integer Fetch (Standard_Boolean& wasBusy);
+
+  //! Checks if there are active build threads.
+  Standard_Boolean HasBusyThreads()
+  {
+    return myNbThreads != 0;
+  }
+
+protected:
+
+  //! Queue of BVH nodes to build.
+  NCollection_Sequence<Standard_Integer> myQueue;
+
+protected:
+
+  //! Manages access serialization of working threads.
+  Standard_Mutex myMutex;
+
+  //! Number of active build threads.
+  Standard_Integer myNbThreads;
+};
+
+#endif // _BVH_BuildQueue_Header