1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef IPC_IPC_MESSAGE_PIPE_READER_H_ 6 #define IPC_IPC_MESSAGE_PIPE_READER_H_ 7 8 #include <stdint.h> 9 10 #include <memory> 11 #include <vector> 12 13 #include "base/atomicops.h" 14 #include "base/compiler_specific.h" 15 #include "base/component_export.h" 16 #include "base/macros.h" 17 #include "base/process/process_handle.h" 18 #include "base/threading/thread_checker.h" 19 #include "ipc/ipc.mojom.h" 20 #include "ipc/ipc_message.h" 21 #include "mojo/public/cpp/bindings/associated_binding.h" 22 #include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h" 23 #include "mojo/public/cpp/system/core.h" 24 #include "mojo/public/cpp/system/message_pipe.h" 25 26 namespace IPC { 27 namespace internal { 28 29 // A helper class to handle bytestream directly over mojo::MessagePipe 30 // in template-method pattern. MessagePipeReader manages the lifetime 31 // of given MessagePipe and participates the event loop, and 32 // read the stream and call the client when it is ready. 33 // 34 // Each client has to: 35 // 36 // * Provide a subclass implemenation of a specific use of a MessagePipe 37 // and implement callbacks. 38 // * Create the subclass instance with a MessagePipeHandle. 39 // The constructor automatically start listening on the pipe. 40 // 41 // All functions must be called on the IO thread, except for Send(), which can 42 // be called on any thread. All |Delegate| functions will be called on the IO 43 // thread. 44 // COMPONENT_EXPORT(IPC)45class COMPONENT_EXPORT(IPC) MessagePipeReader : public mojom::Channel { 46 public: 47 class Delegate { 48 public: 49 virtual void OnPeerPidReceived(int32_t peer_pid) = 0; 50 virtual void OnMessageReceived(const Message& message) = 0; 51 virtual void OnBrokenDataReceived() = 0; 52 virtual void OnPipeError() = 0; 53 virtual void OnAssociatedInterfaceRequest( 54 const std::string& name, 55 mojo::ScopedInterfaceEndpointHandle handle) = 0; 56 }; 57 58 // Builds a reader that reads messages from |receive_handle| and lets 59 // |delegate| know. 60 // 61 // |pipe| is the message pipe handle corresponding to the channel's master 62 // interface. This is the message pipe underlying both |sender| and 63 // |receiver|. 64 // 65 // Both |sender| and |receiver| must be non-null. 66 // 67 // Note that MessagePipeReader doesn't delete |delegate|. 68 MessagePipeReader(mojo::MessagePipeHandle pipe, 69 mojom::ChannelAssociatedPtr sender, 70 mojo::AssociatedInterfaceRequest<mojom::Channel> receiver, 71 Delegate* delegate); 72 ~MessagePipeReader() override; 73 74 // Close and destroy the MessagePipe. 75 void Close(); 76 77 // Return true if the MessagePipe is alive. 78 bool IsValid() { return sender_.is_bound(); } 79 80 // Sends an IPC::Message to the other end of the pipe. Safe to call from any 81 // thread. 82 bool Send(std::unique_ptr<Message> message); 83 84 // Requests an associated interface from the other end of the pipe. 85 void GetRemoteInterface(const std::string& name, 86 mojo::ScopedInterfaceEndpointHandle handle); 87 88 mojom::ChannelAssociatedPtr& sender() { return sender_; } 89 90 protected: 91 void OnPipeClosed(); 92 void OnPipeError(MojoResult error); 93 94 private: 95 // mojom::Channel: 96 void SetPeerPid(int32_t peer_pid) override; 97 void Receive(MessageView message_view) override; 98 void GetAssociatedInterface( 99 const std::string& name, 100 mojom::GenericInterfaceAssociatedRequest request) override; 101 102 // |delegate_| is null once the message pipe is closed. 103 Delegate* delegate_; 104 mojom::ChannelAssociatedPtr sender_; 105 mojo::AssociatedBinding<mojom::Channel> binding_; 106 base::ThreadChecker thread_checker_; 107 108 DISALLOW_COPY_AND_ASSIGN(MessagePipeReader); 109 }; 110 111 } // namespace internal 112 } // namespace IPC 113 114 #endif // IPC_IPC_MESSAGE_PIPE_READER_H_ 115