1 /**************************************************************************** 2 * Copyright (C) 2016 Intel Corporation. All Rights Reserved. 3 * 4 * Permission is hereby granted, free of charge, to any person obtaining a 5 * copy of this software and associated documentation files (the "Software"), 6 * to deal in the Software without restriction, including without limitation 7 * the rights to use, copy, modify, merge, publish, distribute, sublicense, 8 * and/or sell copies of the Software, and to permit persons to whom the 9 * Software is furnished to do so, subject to the following conditions: 10 * 11 * The above copyright notice and this permission notice (including the next 12 * paragraph) shall be included in all copies or substantial portions of the 13 * Software. 14 * 15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 21 * IN THE SOFTWARE. 22 * 23 * @file arena.h 24 * 25 * @brief RingBuffer 26 * The RingBuffer class manages all aspects of the ring buffer including 27 * the head/tail indices, etc. 28 * 29 ******************************************************************************/ 30 #pragma once 31 32 template <typename T> 33 class RingBuffer 34 { 35 public: RingBuffer()36 RingBuffer() : mpRingBuffer(nullptr), mNumEntries(0), mRingHead(0), mRingTail(0) {} 37 ~RingBuffer()38 ~RingBuffer() { Destroy(); } 39 Init(uint32_t numEntries)40 void Init(uint32_t numEntries) 41 { 42 SWR_ASSERT(numEntries > 0); 43 SWR_ASSERT(((1ULL << 32) % numEntries) == 0, 44 "%d is not evenly divisible into 2 ^ 32. Wrap errors will occur!", 45 numEntries); 46 mNumEntries = numEntries; 47 mpRingBuffer = (T*)AlignedMalloc(sizeof(T) * numEntries, 64); 48 SWR_ASSERT(mpRingBuffer != nullptr); 49 memset((void*)mpRingBuffer, 0, sizeof(T) * numEntries); 50 } 51 Destroy()52 void Destroy() 53 { 54 AlignedFree(mpRingBuffer); 55 mpRingBuffer = nullptr; 56 } 57 58 T& operator[](const uint32_t index) 59 { 60 SWR_ASSERT(index < mNumEntries); 61 return mpRingBuffer[index]; 62 } 63 Enqueue()64 INLINE void Enqueue() 65 { 66 mRingHead++; // There's only one producer. 67 // Assert to find wrap-around cases, NEVER ENABLE DURING CHECKIN!! 68 // SWR_REL_ASSERT(mRingHead); 69 } 70 Dequeue()71 INLINE void Dequeue() 72 { 73 InterlockedIncrement(&mRingTail); // There are multiple consumers. 74 } 75 IsEmpty()76 INLINE bool IsEmpty() { return (GetHead() == GetTail()); } 77 IsFull()78 INLINE bool IsFull() 79 { 80 uint32_t numEnqueued = GetHead() - GetTail(); 81 SWR_ASSERT(numEnqueued <= mNumEntries); 82 83 return (numEnqueued == mNumEntries); 84 } 85 GetTail()86 INLINE uint32_t GetTail() volatile { return mRingTail; } GetHead()87 INLINE uint32_t GetHead() volatile { return mRingHead; } 88 89 protected: 90 T* mpRingBuffer; 91 uint32_t mNumEntries; 92 93 OSALIGNLINE(volatile uint32_t) mRingHead; // Consumer Counter 94 OSALIGNLINE(volatile uint32_t) mRingTail; // Producer Counter 95 }; 96