buffer add ownership flag to zero-copy constructor

if this is not set then the memory is not deleted by the buffer instance

hamr_buffer.h

@@ -279,9 +279,11 @@ class HAMR_EXPORT buffer
      *                  driver API is used to determine the device that
      *                  allocated the memory.
      * @param[in] ptr   a pointer to the array
+     * @param[in] take  set non-zero if the buffer should delete the passed
+     *                  memory using the named allocator
      */
     buffer(allocator alloc, const hamr::stream &strm,
-        transfer sync, size_t size, int owner, T *ptr);
+        transfer sync, size_t size, int owner, T *ptr, int take = 1);
 
     /** Construct by directly providing the buffer contents. This can be used
      * for zero-copy transfer of data.  One must also name the allocator type

hamr_buffer_impl.h

@@ -242,14 +242,18 @@ buffer<T>::buffer(allocator alloc, const hamr::stream &strm, transfer sync,
 // --------------------------------------------------------------------------
 template <typename T>
 buffer<T>::buffer(allocator alloc, const hamr::stream &strm, transfer sync,
-    size_t size, int owner, T *ptr) : m_alloc(alloc), m_data(nullptr),
+    size_t size, int owner, T *ptr, int take) : m_alloc(alloc), m_data(nullptr),
     m_size(size), m_capacity(size), m_owner(owner), m_stream(strm),
     m_sync(sync)
 {
     assert_valid_allocator(alloc);
 
     // create the deleter for the passed allocator
-    if (alloc == allocator::cpp)
+    if (!take)
+    {
+        m_data = std::shared_ptr<T>(ptr, [](T*){});
+    }
+    else if (alloc == allocator::cpp)
     {
         m_data = std::shared_ptr<T>(ptr, new_deleter<T>(ptr, m_size));
     }