Expose stream-ordering in scalar and avro APIs

cpp/include/cudf/io/avro.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2024, NVIDIA CORPORATION.
+ * Copyright (c) 2020-2025, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -208,13 +208,15 @@ class avro_reader_options_builder {
  * @endcode
  *
  * @param options Settings for controlling reading behavior
+ * @param stream CUDA stream used for device memory operations and kernel launches
  * @param mr Device memory resource used to allocate device memory of the table in the returned
  * table_with_metadata
  *
  * @return The set of columns along with metadata
  */
 table_with_metadata read_avro(
   avro_reader_options const& options,
+  rmm::cuda_stream_view stream      = cudf::get_default_stream(),
   rmm::device_async_resource_ref mr = cudf::get_current_device_resource_ref());
 
 /** @} */  // end of group

cpp/include/cudf/scalar/scalar.hpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2024, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2025, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -177,9 +177,12 @@ class fixed_width_scalar : public scalar {
   void set_value(T value, rmm::cuda_stream_view stream = cudf::get_default_stream());
 
   /**
-   * @brief Explicit conversion operator to get the value of the scalar on the host.
+   * @brief Returns the value of the scalar on the host.
+   *
+   * @param stream CUDA stream used for device memory operations.
+   * @return The value of the scalar
    */
-  explicit operator value_type() const;
+  T get_value(rmm::cuda_stream_view stream = cudf::get_default_stream()) const;
 
   /**
    * @brief Get the value of the scalar.
@@ -386,7 +389,7 @@ class fixed_point_scalar : public scalar {
                      rmm::device_async_resource_ref mr = cudf::get_current_device_resource_ref());
 
   /**
-   * @brief Get the value of the scalar.
+   * @brief Get the unscaled value of the scalar.
    *
    * @param stream CUDA stream used for device memory operations.
    * @return The value of the scalar
@@ -403,9 +406,12 @@ class fixed_point_scalar : public scalar {
     rmm::cuda_stream_view stream = cudf::get_default_stream()) const;
 
   /**
-   * @brief Explicit conversion operator to get the value of the scalar on the host.
+   * @brief Returns the value of the scalar as decimal32, decimal64 or decimal128 on the host.
+   *
+   * @param stream CUDA stream used for device memory operations.
+   * @return The value of the scalar
    */
-  explicit operator value_type() const;
+  T get_value(rmm::cuda_stream_view stream = cudf::get_default_stream()) const;
 
   /**
    * @brief Returns a raw pointer to the value in device memory.
@@ -516,9 +522,12 @@ class string_scalar : public scalar {
                 rmm::device_async_resource_ref mr = cudf::get_current_device_resource_ref());
 
   /**
-   * @brief Explicit conversion operator to get the value of the scalar in a host std::string.
+   * @brief Returns the value of the scalar in a host std::string.
+   *
+   * @param stream CUDA stream used for device memory operations.
+   * @return The value of the scalar
    */
-  explicit operator std::string() const;
+  std::string get_value(rmm::cuda_stream_view stream = cudf::get_default_stream()) const;
 
   /**
    * @brief Get the value of the scalar in a host std::string.

cpp/src/io/functions.cpp

@@ -189,7 +189,9 @@ std::vector<std::unique_ptr<data_sink>> make_datasinks(sink_info const& info)
 
 }  // namespace
 
-table_with_metadata read_avro(avro_reader_options const& options, rmm::device_async_resource_ref mr)
+table_with_metadata read_avro(avro_reader_options const& options,
+                              rmm::cuda_stream_view stream,
+                              rmm::device_async_resource_ref mr)
 {
   namespace avro = cudf::io::detail::avro;
 
@@ -199,7 +201,7 @@ table_with_metadata read_avro(avro_reader_options const& options, rmm::device_as
 
   CUDF_EXPECTS(datasources.size() == 1, "Only a single source is currently supported.");
 
-  return avro::read_avro(std::move(datasources[0]), options, cudf::get_default_stream(), mr);
+  return avro::read_avro(std::move(datasources[0]), options, stream, mr);
 }
 
 table_with_metadata read_json(json_reader_options options,

cpp/src/scalar/scalar.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2024, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2025, NVIDIA CORPORATION.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -110,7 +110,10 @@ size_type string_scalar::size() const { return _data.size(); }
 
 char const* string_scalar::data() const { return static_cast<char const*>(_data.data()); }
 
-string_scalar::operator std::string() const { return this->to_string(cudf::get_default_stream()); }
+std::string string_scalar::get_value(rmm::cuda_stream_view stream) const
+{
+  return this->to_string(stream);
+}
 
 std::string string_scalar::to_string(rmm::cuda_stream_view stream) const
 {
@@ -184,9 +187,9 @@ T fixed_point_scalar<T>::fixed_point_value(rmm::cuda_stream_view stream) const
 }
 
 template <typename T>
-fixed_point_scalar<T>::operator value_type() const
+T fixed_point_scalar<T>::get_value(rmm::cuda_stream_view stream) const
 {
-  return this->fixed_point_value(cudf::get_default_stream());
+  return this->fixed_point_value(stream);
 }
 
 template <typename T>
@@ -267,9 +270,9 @@ T const* fixed_width_scalar<T>::data() const
 }
 
 template <typename T>
-fixed_width_scalar<T>::operator value_type() const
+T fixed_width_scalar<T>::get_value(rmm::cuda_stream_view stream) const
 {
-  return this->value(cudf::get_default_stream());
+  return this->value(stream);
 }
 
 /**

cpp/tests/CMakeLists.txt

@@ -725,6 +725,7 @@ ConfigureTest(STREAM_REPLACE_TEST streams/replace_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_RESHAPE_TEST streams/reshape_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_ROLLING_TEST streams/rolling_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_ROUND_TEST streams/round_test.cpp STREAM_MODE testing)
+ConfigureTest(STREAM_SCALAR_TEST streams/scalar_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_SEARCH_TEST streams/search_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_SORTING_TEST streams/sorting_test.cpp STREAM_MODE testing)
 ConfigureTest(STREAM_STREAM_COMPACTION_TEST streams/stream_compaction_test.cpp STREAM_MODE testing)

cpp/tests/binaryop/assert-binops.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019-2023, NVIDIA CORPORATION.
+ * Copyright (c) 2019-2025, NVIDIA CORPORATION.
  *
  * Copyright 2018-2019 BlazingDB, Inc.
  *     Copyright 2018 Christian Noboa Mardini <christian@blazingdb.com>
@@ -81,7 +81,7 @@ void ASSERT_BINOP(cudf::column_view const& out,
                   TypeOp&& op,
                   ValueComparator const& value_comparator = ValueComparator())
 {
-  auto lhs_h    = static_cast<ScalarType const&>(lhs).operator TypeLhs();
+  auto lhs_h    = static_cast<ScalarType const&>(lhs).get_value(cudf::get_default_stream());
   auto rhs_h    = cudf::test::to_host<TypeRhs>(rhs);
   auto rhs_data = rhs_h.first;
   auto out_h    = cudf::test::to_host<TypeOut>(out);
@@ -129,7 +129,7 @@ void ASSERT_BINOP(cudf::column_view const& out,
                   TypeOp&& op,
                   ValueComparator const& value_comparator = ValueComparator())
 {
-  auto rhs_h    = static_cast<ScalarType const&>(rhs).operator TypeRhs();
+  auto rhs_h    = static_cast<ScalarType const&>(rhs).get_value(cudf::get_default_stream());
   auto lhs_h    = cudf::test::to_host<TypeLhs>(lhs);
   auto lhs_data = lhs_h.first;
   auto out_h    = cudf::test::to_host<TypeOut>(out);

cpp/tests/streams/scalar_test.cpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2023-2025, NVIDIA CORPORATION.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <cudf_test/base_fixture.hpp>
+#include <cudf_test/column_wrapper.hpp>
+#include <cudf_test/default_stream.hpp>
+#include <cudf_test/table_utilities.hpp>
+#include <cudf_test/testing_main.hpp>
+#include <cudf_test/type_lists.hpp>
+
+#include <cudf/scalar/scalar.hpp>
+
+template <typename T>
+struct TypedScalarTest : public cudf::test::BaseFixture {};
+
+TYPED_TEST_SUITE(TypedScalarTest, cudf::test::FixedWidthTypes);
+
+TYPED_TEST(TypedScalarTest, DefaultValidity)
+{
+  using Type = cudf::device_storage_type_t<TypeParam>;
+  Type value = static_cast<Type>(cudf::test::make_type_param_scalar<TypeParam>(7));
+  cudf::scalar_type_t<TypeParam> s(value);
+  CUDF_EXPECT_NO_THROW(s.get_value(cudf::test::get_default_stream()));
+
+  EXPECT_TRUE(s.is_valid());
+  EXPECT_EQ(value, s.value());
+}
+
+struct StringScalarTest : public cudf::test::BaseFixture {};
+
+TEST_F(StringScalarTest, DefaultValidity)
+{
+  std::string value = "test string";
+  auto s            = cudf::string_scalar(value);
+  CUDF_EXPECT_NO_THROW(s.get_value(cudf::test::get_default_stream()));
+  EXPECT_TRUE(s.is_valid());
+}