1 // Copyright 2020 The Pigweed Authors 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); you may not 4 // use this file except in compliance with the License. You may obtain a copy of 5 // the License at 6 // 7 // https://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 11 // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the 12 // License for the specific language governing permissions and limitations under 13 // the License. 14 #pragma once 15 16 #include <algorithm> 17 18 #include "pw_rpc/channel.h" 19 #include "pw_sync/lock_annotations.h" 20 #include "pw_sync/mutex.h" 21 22 namespace pw::rpc { 23 24 // Wraps an RPC ChannelOutput implementation with a mutex to synchronize its 25 // acquire and release buffer operations. This can be used to allow a simple 26 // ChannelOutput implementation to run in multi-threaded contexts. More complex 27 // implementations may want to roll their own synchronization. 28 template <typename BaseChannelOutput> 29 class PW_LOCKABLE("pw::rpc::SynchronizedChannelOutput") 30 SynchronizedChannelOutput final : public BaseChannelOutput { 31 public: 32 template <typename... Args> SynchronizedChannelOutput(sync::Mutex & mutex,Args &&...args)33 constexpr SynchronizedChannelOutput(sync::Mutex& mutex, Args&&... args) 34 : BaseChannelOutput(std::forward<Args>(args)...), mutex_(mutex) {} 35 AcquireBuffer()36 std::span<std::byte> AcquireBuffer() final PW_EXCLUSIVE_LOCK_FUNCTION() { 37 mutex_.lock(); 38 return BaseChannelOutput::AcquireBuffer(); 39 } 40 SendAndReleaseBuffer(std::span<const std::byte> buffer)41 Status SendAndReleaseBuffer(std::span<const std::byte> buffer) final 42 PW_UNLOCK_FUNCTION() { 43 Status status = BaseChannelOutput::SendAndReleaseBuffer(buffer); 44 mutex_.unlock(); 45 return status; 46 } 47 48 private: 49 sync::Mutex& mutex_; 50 }; 51 52 } // namespace pw::rpc 53