Merge pull request #780 from jszuppe/fix_memory_leak_746

Fix memory leak

Author: jszuppe

include/boost/compute/iterator/buffer_iterator.hpp

@@ -65,6 +65,14 @@ struct buffer_iterator_index_expr
     {
     }
 
+    buffer_iterator_index_expr(const buffer_iterator_index_expr& other)
+        : m_buffer(other.m_buffer.get(), false),
+          m_index(other.m_index),
+          m_address_space(other.m_address_space),
+          m_expr(other.m_expr)
+    {
+    }
+
     ~buffer_iterator_index_expr()
     {
         // set buffer to null so that its reference count will

test/test_reduce.cpp

@@ -276,4 +276,23 @@ BOOST_AUTO_TEST_CASE(reduce_uchar_to_float)
     BOOST_CHECK_EQUAL(sum, 500);
 }
 
+// Test case for https://github.com/boostorg/compute/issues/746
+BOOST_AUTO_TEST_CASE(buffer_reference_count_test)
+{
+    using compute::uint_;
+
+    compute::vector<uint_> vector(8, context);
+    const compute::buffer& b = vector.get_buffer();
+    uint_ rc1 = b.get_info<CL_MEM_REFERENCE_COUNT>();
+    {
+        compute::fill(vector.begin(), vector.end(), uint_(2), queue);
+
+        uint_ product;
+        compute::reduce(vector.begin(), vector.end(), &product, compute::multiplies<uint_>(), queue);
+        BOOST_CHECK_EQUAL(product, uint_(256));
+    }
+    uint_ rc2 = b.get_info<CL_MEM_REFERENCE_COUNT>();
+    BOOST_CHECK_EQUAL(rc1, rc2);
+}
+
 BOOST_AUTO_TEST_SUITE_END()