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Diffstat (limited to 'ipc/ipc_channel.h')
-rw-r--r-- | ipc/ipc_channel.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/ipc/ipc_channel.h b/ipc/ipc_channel.h new file mode 100644 index 0000000..1ecffdf --- /dev/null +++ b/ipc/ipc_channel.h @@ -0,0 +1,123 @@ +// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. + +#ifndef IPC_IPC_CHANNEL_H_ +#define IPC_IPC_CHANNEL_H_ + +#include "ipc/ipc_message.h" + +namespace IPC { + +//------------------------------------------------------------------------------ + +class Channel : public Message::Sender { + // Security tests need access to the pipe handle. + friend class ChannelTest; + + public: + // Implemented by consumers of a Channel to receive messages. + class Listener { + public: + virtual ~Listener() {} + + // Called when a message is received. + virtual void OnMessageReceived(const Message& message) = 0; + + // Called when the channel is connected and we have received the internal + // Hello message from the peer. + virtual void OnChannelConnected(int32 peer_pid) {} + + // Called when an error is detected that causes the channel to close. + // This method is not called when a channel is closed normally. + virtual void OnChannelError() {} + }; + + enum Mode { + MODE_SERVER, + MODE_CLIENT + }; + + enum { + // The maximum message size in bytes. Attempting to receive a + // message of this size or bigger results in a channel error. + kMaximumMessageSize = 256 * 1024 * 1024, + + // Ammount of data to read at once from the pipe. + kReadBufferSize = 4 * 1024 + }; + + // Initialize a Channel. + // + // |channel_id| identifies the communication Channel. + // |mode| specifies whether this Channel is to operate in server mode or + // client mode. In server mode, the Channel is responsible for setting up the + // IPC object, whereas in client mode, the Channel merely connects to the + // already established IPC object. + // |listener| receives a callback on the current thread for each newly + // received message. + // + Channel(const std::wstring& channel_id, Mode mode, Listener* listener); + + ~Channel(); + + // Connect the pipe. On the server side, this will initiate + // waiting for connections. On the client, it attempts to + // connect to a pre-existing pipe. Note, calling Connect() + // will not block the calling thread and may complete + // asynchronously. + bool Connect(); + + // Close this Channel explicitly. May be called multiple times. + void Close(); + + // Modify the Channel's listener. + void set_listener(Listener* listener); + + // Send a message over the Channel to the listener on the other end. + // + // |message| must be allocated using operator new. This object will be + // deleted once the contents of the Message have been sent. + // + // FIXME bug 551500: the channel does not notice failures, so if the + // renderer crashes, it will silently succeed, leaking the parameter. + // At least the leak will be fixed by... + // + virtual bool Send(Message* message); + +#if defined(OS_POSIX) + // On POSIX an IPC::Channel wraps a socketpair(), this method returns the + // FD # for the client end of the socket and the equivalent FD# to use for + // mapping it into the Child process. + // This method may only be called on the server side of a channel. + // + // If the kTestingChannelID flag is specified on the command line then + // a named FIFO is used as the channel transport mechanism rather than a + // socketpair() in which case this method returns -1 for both parameters. + void GetClientFileDescriptorMapping(int *src_fd, int *dest_fd); + + // Call this method on the server side of the IPC Channel once a client is + // connected in order to close the client side of the socketpair(). + void OnClientConnected(); +#endif // defined(OS_POSIX) + + private: + // PIMPL to which all channel calls are delegated. + class ChannelImpl; + ChannelImpl *channel_impl_; + + // The Hello message is internal to the Channel class. It is sent + // by the peer when the channel is connected. The message contains + // just the process id (pid). The message has a special routing_id + // (MSG_ROUTING_NONE) and type (HELLO_MESSAGE_TYPE). + enum { + HELLO_MESSAGE_TYPE = kuint16max // Maximum value of message type (uint16), + // to avoid conflicting with normal + // message types, which are enumeration + // constants starting from 0. + }; +}; + +} // namespace IPC + +#endif // IPC_IPC_CHANNEL_H_ |