1 /****************************************************************************
2 * Copyright (C) 2016 Intel Corporation. All Rights Reserved.
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:
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
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
26 * The RingBuffer class manages all aspects of the ring buffer including
27 * the head/tail indices, etc.
29 ******************************************************************************/
36 RingBuffer() : mpRingBuffer(nullptr), mNumEntries(0), mRingHead(0), mRingTail(0) {}
38 ~RingBuffer() { Destroy(); }
40 void Init(uint32_t numEntries
)
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!",
46 mNumEntries
= numEntries
;
47 mpRingBuffer
= (T
*)AlignedMalloc(sizeof(T
) * numEntries
, 64);
48 SWR_ASSERT(mpRingBuffer
!= nullptr);
49 memset((void*)mpRingBuffer
, 0, sizeof(T
) * numEntries
);
54 AlignedFree(mpRingBuffer
);
55 mpRingBuffer
= nullptr;
58 T
& operator[](const uint32_t index
)
60 SWR_ASSERT(index
< mNumEntries
);
61 return mpRingBuffer
[index
];
66 mRingHead
++; // There's only one producer.
67 // Assert to find wrap-around cases, NEVER ENABLE DURING CHECKIN!!
68 // SWR_REL_ASSERT(mRingHead);
73 InterlockedIncrement(&mRingTail
); // There are multiple consumers.
76 INLINE
bool IsEmpty() { return (GetHead() == GetTail()); }
80 uint32_t numEnqueued
= GetHead() - GetTail();
81 SWR_ASSERT(numEnqueued
<= mNumEntries
);
83 return (numEnqueued
== mNumEntries
);
86 INLINE
uint32_t GetTail() volatile { return mRingTail
; }
87 INLINE
uint32_t GetHead() volatile { return mRingHead
; }
93 OSALIGNLINE(volatile uint32_t) mRingHead
; // Consumer Counter
94 OSALIGNLINE(volatile uint32_t) mRingTail
; // Producer Counter