openmp/libomptarget/deviceRTLs/common/state-queue.h

   1 //===--------- statequeue.h - NVPTX OpenMP GPU State Queue ------- CUDA -*-===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file contains a queue to hand out OpenMP state objects to teams of
  10 // one or more kernels.
  11 //
  12 // Reference:
  13 // Thomas R.W. Scogland and Wu-chun Feng. 2015.
  14 // Design and Evaluation of Scalable Concurrent Queues for Many-Core
  15 // Architectures. International Conference on Performance Engineering.
  16 //
  17 //===----------------------------------------------------------------------===//
  18
  19 #ifndef __STATE_QUEUE_H
  20 #define __STATE_QUEUE_H
  21
  22 #include <stdint.h>
  23
  24 #include "target_impl.h"
  25
  26 template <typename ElementType, uint32_t SIZE> class omptarget_nvptx_Queue {
  27 private:
  28   ElementType elements[SIZE];
  29   volatile ElementType *elementQueue[SIZE];
  30   volatile uint32_t head;
  31   volatile uint32_t ids[SIZE];
  32   volatile uint32_t tail;
  33
  34   static const uint32_t MAX_ID = (1u << 31) / SIZE / 2;
  35   INLINE uint32_t ENQUEUE_TICKET();
  36   INLINE uint32_t DEQUEUE_TICKET();
  37   INLINE static uint32_t ID(uint32_t ticket);
  38   INLINE bool IsServing(uint32_t slot, uint32_t id);
  39   INLINE void PushElement(uint32_t slot, ElementType *element);
  40   INLINE ElementType *PopElement(uint32_t slot);
  41   INLINE void DoneServing(uint32_t slot, uint32_t id);
  42
  43 public:
  44   INLINE omptarget_nvptx_Queue() {}
  45   INLINE void Enqueue(ElementType *element);
  46   INLINE ElementType *Dequeue();
  47 };
  48
  49 #include "state-queuei.h"
  50
  51 #endif