1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ 2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */ 3 /* This Source Code Form is subject to the terms of the Mozilla Public 4 * License, v. 2.0. If a copy of the MPL was not distributed with this 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 6 7 #ifndef mozilla_ipc_AutoTransportDescriptor_h 8 #define mozilla_ipc_AutoTransportDescriptor_h 9 10 #include <utility> 11 12 #include "mozilla/ipc/Transport.h" 13 #include "mozilla/Result.h" 14 15 namespace mozilla::ipc { 16 17 class AutoTransportDescriptor final { 18 public: 19 AutoTransportDescriptor() = default; AutoTransportDescriptor(TransportDescriptor aTransport)20 explicit AutoTransportDescriptor(TransportDescriptor aTransport) 21 : mTransport(aTransport), mValid(true) {} 22 ~AutoTransportDescriptor(); 23 24 AutoTransportDescriptor(AutoTransportDescriptor&& aOther) noexcept; 25 AutoTransportDescriptor& operator=(AutoTransportDescriptor&& aOther) noexcept; 26 27 static Result<std::pair<AutoTransportDescriptor, AutoTransportDescriptor>, 28 nsresult> 29 Create(int32_t aProcIdOne); 30 31 AutoTransportDescriptor Duplicate() const; 32 33 // NOTE: This will consume this transport descriptor, making it invalid. 34 UniquePtr<Transport> Open(Transport::Mode aMode); 35 36 explicit operator bool() const { return mValid; } 37 38 private: 39 friend struct IPC::ParamTraits<AutoTransportDescriptor>; 40 41 TransportDescriptor mTransport; 42 bool mValid = false; 43 }; 44 45 } // namespace mozilla::ipc 46 47 namespace IPC { 48 49 template <> 50 struct ParamTraits<mozilla::ipc::AutoTransportDescriptor> { 51 using paramType = mozilla::ipc::AutoTransportDescriptor; 52 static void Write(Message* aMsg, paramType&& aParam) { 53 WriteParam(aMsg, aParam.mValid); 54 if (aParam.mValid) { 55 // TransportDescriptor's serialization code takes it by `const T&`, 56 // however, it actually closes the handles when passed, so we need to mark 57 // our state as invalid after sending. 58 WriteParam(aMsg, aParam.mTransport); 59 aParam.mValid = false; 60 } 61 } 62 static bool Read(const Message* aMsg, PickleIterator* aIter, 63 paramType* aResult) { 64 bool valid = false; 65 if (!ReadParam(aMsg, aIter, &valid)) { 66 return false; 67 } 68 if (!valid) { 69 *aResult = mozilla::ipc::AutoTransportDescriptor{}; 70 return true; 71 } 72 73 mozilla::ipc::TransportDescriptor descr; 74 if (!ReadParam(aMsg, aIter, &descr)) { 75 return false; 76 } 77 *aResult = mozilla::ipc::AutoTransportDescriptor{descr}; 78 return true; 79 } 80 }; 81 82 } // namespace IPC 83 84 #endif 85