Glenn Kasten | 7cc8f54 | 2016-12-01 16:12:59 -0800 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2016 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
Glenn Kasten | 7225a3d | 2016-11-30 11:05:32 -0800 | [diff] [blame] | 17 | #include <errno.h> |
| 18 | #include <limits.h> |
Glenn Kasten | 7cc8f54 | 2016-12-01 16:12:59 -0800 | [diff] [blame] | 19 | #include <audio_utils/fifo_index.h> |
| 20 | #include <audio_utils/futex.h> |
| 21 | |
| 22 | // These are not implemented within <audio_utils/fifo_index.h> |
| 23 | // so that we don't expose futex. |
| 24 | |
| 25 | uint32_t audio_utils_fifo_index::loadAcquire() |
| 26 | { |
| 27 | return atomic_load_explicit(&mIndex, std::memory_order_acquire); |
| 28 | } |
| 29 | |
Glenn Kasten | a7a7bb6 | 2017-03-09 14:09:51 -0800 | [diff] [blame] | 30 | // FIXME should inline this, so that writer32 can also inline it |
Glenn Kasten | 7cc8f54 | 2016-12-01 16:12:59 -0800 | [diff] [blame] | 31 | void audio_utils_fifo_index::storeRelease(uint32_t value) |
| 32 | { |
| 33 | atomic_store_explicit(&mIndex, value, std::memory_order_release); |
| 34 | } |
| 35 | |
| 36 | int audio_utils_fifo_index::wait(int op, uint32_t expected, const struct timespec *timeout) |
| 37 | { |
| 38 | return sys_futex(&mIndex, op, expected, timeout, NULL, 0); |
| 39 | } |
| 40 | |
| 41 | int audio_utils_fifo_index::wake(int op, int waiters) |
| 42 | { |
| 43 | return sys_futex(&mIndex, op, waiters, NULL, NULL, 0); |
| 44 | } |
Glenn Kasten | 7225a3d | 2016-11-30 11:05:32 -0800 | [diff] [blame] | 45 | |
Glenn Kasten | 2f99531 | 2016-12-16 12:42:26 -0800 | [diff] [blame] | 46 | uint32_t audio_utils_fifo_index::loadConsume() |
| 47 | { |
| 48 | return atomic_load_explicit(&mIndex, std::memory_order_consume); |
| 49 | } |
| 50 | |
Glenn Kasten | 7225a3d | 2016-11-30 11:05:32 -0800 | [diff] [blame] | 51 | //// |
| 52 | |
| 53 | RefIndexDeferredStoreReleaseDeferredWake::RefIndexDeferredStoreReleaseDeferredWake( |
| 54 | audio_utils_fifo_index& index) |
| 55 | : mIndex(index), mValue(0), mWriteback(false), mWaiters(0), mWakeOp(FUTEX_WAIT_PRIVATE) |
| 56 | { |
| 57 | } |
| 58 | |
| 59 | RefIndexDeferredStoreReleaseDeferredWake::~RefIndexDeferredStoreReleaseDeferredWake() |
| 60 | { |
| 61 | writeback(); |
| 62 | wakeNowIfNeeded(); |
| 63 | } |
| 64 | |
| 65 | void RefIndexDeferredStoreReleaseDeferredWake::set(uint32_t value) { |
| 66 | mValue = value; |
| 67 | mWriteback = true; |
| 68 | } |
| 69 | |
| 70 | void RefIndexDeferredStoreReleaseDeferredWake::writeback() |
| 71 | { |
| 72 | if (mWriteback) { |
| 73 | // TODO When part of a collection, should use relaxed for all but the last writeback |
| 74 | mIndex.storeRelease(mValue); |
| 75 | mWriteback = false; |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | void RefIndexDeferredStoreReleaseDeferredWake::writethrough(uint32_t value) { |
| 80 | set(value); |
| 81 | writeback(); |
| 82 | } |
| 83 | |
| 84 | void RefIndexDeferredStoreReleaseDeferredWake::wakeDeferred(int op, int waiters) |
| 85 | { |
| 86 | if (waiters <= 0) { |
| 87 | return; |
| 88 | } |
| 89 | // default is FUTEX_WAKE_PRIVATE |
| 90 | if (op == FUTEX_WAKE) { |
| 91 | mWakeOp = FUTEX_WAKE; |
| 92 | } |
| 93 | if (waiters < INT_MAX - mWaiters) { |
| 94 | mWaiters += waiters; |
| 95 | } else { |
| 96 | mWaiters = INT_MAX; |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | void RefIndexDeferredStoreReleaseDeferredWake::wakeNowIfNeeded() |
| 101 | { |
| 102 | if (mWaiters > 0) { |
| 103 | mIndex.wake(mWakeOp, mWaiters); |
| 104 | mWaiters = 0; |
| 105 | mWakeOp = FUTEX_WAKE_PRIVATE; |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | void RefIndexDeferredStoreReleaseDeferredWake::wakeNow(int op, int waiters) |
| 110 | { |
| 111 | wakeDeferred(op, waiters); |
| 112 | wakeNowIfNeeded(); |
| 113 | } |
| 114 | |
| 115 | //// |
| 116 | |
| 117 | RefIndexCachedLoadAcquireDeferredWait::RefIndexCachedLoadAcquireDeferredWait( |
| 118 | audio_utils_fifo_index& index) |
| 119 | : mIndex(index), mValue(0), mLoaded(false) |
| 120 | { |
| 121 | } |
| 122 | |
| 123 | RefIndexCachedLoadAcquireDeferredWait::~RefIndexCachedLoadAcquireDeferredWait() |
| 124 | { |
| 125 | } |
| 126 | |
| 127 | uint32_t RefIndexCachedLoadAcquireDeferredWait::get() |
| 128 | { |
| 129 | prefetch(); |
| 130 | return mValue; |
| 131 | } |
| 132 | |
| 133 | void RefIndexCachedLoadAcquireDeferredWait::prefetch() |
| 134 | { |
| 135 | if (!mLoaded) { |
| 136 | // TODO When part of a collection, should use relaxed for all but the last load |
| 137 | mValue = mIndex.loadAcquire(); |
| 138 | mLoaded = true; |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | void RefIndexCachedLoadAcquireDeferredWait::invalidate() |
| 143 | { |
| 144 | mLoaded = false; |
| 145 | } |
| 146 | |
| 147 | #if 0 |
| 148 | uint32_t RefIndexCachedLoadAcquireDeferredWait::readthrough() |
| 149 | { |
| 150 | invalidate(); |
| 151 | return get(); |
| 152 | } |
| 153 | #endif |
| 154 | |
| 155 | int RefIndexCachedLoadAcquireDeferredWait::wait(int op, const struct timespec *timeout) |
| 156 | { |
| 157 | if (!mLoaded) { |
| 158 | return -EINVAL; |
| 159 | } |
| 160 | int err = mIndex.wait(op, mValue /*expected*/, timeout); |
| 161 | invalidate(); |
| 162 | return err; |
| 163 | } |