1 /* 2 * Copyright (C) 2017 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 17 #include "perfetto/ipc/deferred.h" 18 19 #include "google/protobuf/message_lite.h" 20 #include "perfetto/base/logging.h" 21 22 namespace perfetto { 23 namespace ipc { 24 DeferredBase(std::function<void (AsyncResult<ProtoMessage>)> callback)25DeferredBase::DeferredBase( 26 std::function<void(AsyncResult<ProtoMessage>)> callback) 27 : callback_(std::move(callback)) {} 28 ~DeferredBase()29DeferredBase::~DeferredBase() { 30 if (callback_) 31 Reject(); 32 } 33 34 // Can't just use "= default" here because the default move operator for 35 // std::function doesn't necessarily swap and hence can leave a copy of the 36 // bind state around, which is undesirable. DeferredBase(DeferredBase && other)37DeferredBase::DeferredBase(DeferredBase&& other) noexcept { 38 Move(other); 39 } 40 operator =(DeferredBase && other)41DeferredBase& DeferredBase::operator=(DeferredBase&& other) { 42 if (callback_) 43 Reject(); 44 Move(other); 45 return *this; 46 } 47 Move(DeferredBase & other)48void DeferredBase::Move(DeferredBase& other) { 49 callback_ = std::move(other.callback_); 50 other.callback_ = nullptr; 51 } 52 Bind(std::function<void (AsyncResult<ProtoMessage>)> callback)53void DeferredBase::Bind( 54 std::function<void(AsyncResult<ProtoMessage>)> callback) { 55 callback_ = std::move(callback); 56 } 57 IsBound() const58bool DeferredBase::IsBound() const { 59 return !!callback_; 60 } 61 Resolve(AsyncResult<ProtoMessage> async_result)62void DeferredBase::Resolve(AsyncResult<ProtoMessage> async_result) { 63 if (!callback_) { 64 PERFETTO_DFATAL("No callback set."); 65 return; 66 } 67 bool has_more = async_result.has_more(); 68 callback_(std::move(async_result)); 69 if (!has_more) 70 callback_ = nullptr; 71 } 72 73 // Resolves with a nullptr |msg_|, signalling failure to |callback_|. Reject()74void DeferredBase::Reject() { 75 Resolve(AsyncResult<ProtoMessage>()); 76 } 77 78 } // namespace ipc 79 } // namespace perfetto 80