Henrik Boström | 27c2936 | 2019-10-21 15:21:55 +0200 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2019 The WebRTC Project Authors. All rights reserved. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license |
| 5 | * that can be found in the LICENSE file in the root of the source |
| 6 | * tree. An additional intellectual property rights grant can be found |
| 7 | * in the file PATENTS. All contributing project authors may |
| 8 | * be found in the AUTHORS file in the root of the source tree. |
| 9 | */ |
| 10 | |
| 11 | #include "rtc_base/operations_chain.h" |
| 12 | |
| 13 | #include "rtc_base/checks.h" |
| 14 | |
| 15 | namespace rtc { |
| 16 | |
| 17 | OperationsChain::CallbackHandle::CallbackHandle( |
| 18 | scoped_refptr<OperationsChain> operations_chain) |
| 19 | : operations_chain_(std::move(operations_chain)) {} |
| 20 | |
| 21 | OperationsChain::CallbackHandle::~CallbackHandle() { |
| 22 | RTC_DCHECK(has_run_); |
| 23 | } |
| 24 | |
| 25 | void OperationsChain::CallbackHandle::OnOperationComplete() { |
| 26 | RTC_DCHECK(!has_run_); |
| 27 | #ifdef RTC_DCHECK_IS_ON |
| 28 | has_run_ = true; |
| 29 | #endif // RTC_DCHECK_IS_ON |
| 30 | operations_chain_->OnOperationComplete(); |
| 31 | // We have no reason to keep the |operations_chain_| alive through reference |
| 32 | // counting anymore. |
| 33 | operations_chain_ = nullptr; |
| 34 | } |
| 35 | |
| 36 | // static |
| 37 | scoped_refptr<OperationsChain> OperationsChain::Create() { |
| 38 | return new OperationsChain(); |
| 39 | } |
| 40 | |
| 41 | OperationsChain::OperationsChain() : RefCountedObject() { |
| 42 | RTC_DCHECK_RUN_ON(&sequence_checker_); |
| 43 | } |
| 44 | |
| 45 | OperationsChain::~OperationsChain() { |
| 46 | // Operations keep the chain alive through reference counting so this should |
| 47 | // not be possible. The fact that the chain is empty makes it safe to |
| 48 | // destroy the OperationsChain on any sequence. |
| 49 | RTC_DCHECK(chained_operations_.empty()); |
| 50 | } |
| 51 | |
| 52 | std::function<void()> OperationsChain::CreateOperationsChainCallback() { |
| 53 | return [handle = rtc::scoped_refptr<CallbackHandle>( |
| 54 | new CallbackHandle(this))]() { handle->OnOperationComplete(); }; |
| 55 | } |
| 56 | |
| 57 | void OperationsChain::OnOperationComplete() { |
| 58 | RTC_DCHECK_RUN_ON(&sequence_checker_); |
| 59 | // The front element is the operation that just completed, remove it. |
| 60 | RTC_DCHECK(!chained_operations_.empty()); |
| 61 | chained_operations_.pop(); |
| 62 | // If there are any other operations chained, execute the next one. |
| 63 | if (!chained_operations_.empty()) { |
| 64 | chained_operations_.front()->Run(); |
| 65 | } |
| 66 | } |
| 67 | |
| 68 | } // namespace rtc |