Cython extension for rmm::cuda_stream_pool (#818)

Authors:
  - Divye Gala (https://github.com/divyegala)

Approvers:
  - Mark Harris (https://github.com/harrism)
  - GALI PREM SAGAR (https://github.com/galipremsagar)
  - Ashwin Srinath (https://github.com/shwina)

URL: #818

include/rmm/cuda_stream_view.hpp

@@ -57,9 +57,9 @@ class cuda_stream_view {
   constexpr cudaStream_t value() const noexcept { return stream_; }
 
   /**
-   * @brief Explicit conversion to cudaStream_t.
+   * @brief Implicit conversion to cudaStream_t.
    */
-  explicit constexpr operator cudaStream_t() const noexcept { return value(); }
+  constexpr operator cudaStream_t() const noexcept { return value(); }
 
   /**
    * @brief Return true if the wrapped stream is the CUDA per-thread default stream.

python/rmm/_lib/cuda_stream_pool.pxd

@@ -0,0 +1,24 @@
+# Copyright (c) 2021, 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.
+
+cimport cython
+
+from rmm._lib.cuda_stream_view cimport cuda_stream_view
+
+cdef extern from "rmm/cuda_stream_pool.hpp" namespace "rmm" nogil:
+    cdef cppclass cuda_stream_pool:
+        cuda_stream_pool(size_t pool_size)
+        cuda_stream_view get_stream()
+        cuda_stream_view get_stream(size_t stream_id) except +
+        size_t get_pool_size()