chore: import upstream snapshot with attribution

paddle/phi/backends/gpu/cuda/gpu_event_timer.h

@@ -0,0 +1,85 @@
+// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
+//
+// 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.
+
+#pragma once
+
+#include <memory>
+#include <vector>
+#include "cuda_runtime.h"  // NOLINT
+#include "paddle/common/enforce.h"
+#include "paddle/common/macros.h"
+#include "paddle/phi/common/place.h"
+
+namespace phi {
+
+class EventPair {
+  DISABLE_COPY_AND_ASSIGN(EventPair);
+
+ public:
+  EventPair();
+
+  ~EventPair() PADDLE_MAY_THROW;
+
+  void Start(cudaStream_t stream);
+
+  void Stop(cudaStream_t stream);
+
+  void Reset();
+
+  double Elapsed();
+
+ private:
+  cudaEvent_t start_;
+  cudaEvent_t end_;
+  bool started_;
+};
+
+class GPUEventTimer {
+  DISABLE_COPY_AND_ASSIGN(GPUEventTimer);
+
+ public:
+  explicit GPUEventTimer(phi::GPUPlace place);
+
+  void Start(cudaStream_t stream);
+
+  void Stop(cudaStream_t stream);
+
+  void Start();
+
+  void Stop();
+
+  void Reset();
+
+  double Elapsed(bool reset);
+
+  std::vector<double> ElapsedList(bool reset);
+
+  void PreAlloc(size_t n);
+
+  void ShrinkToFit();
+
+  size_t Size() const;
+
+  size_t Capacity() const;
+
+ private:
+  EventPair *GetLatest();
+
+ private:
+  std::vector<std::unique_ptr<EventPair>> events_;
+  size_t length_;
+  cudaStream_t default_stream_;
+};
+
+}  // namespace phi