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Diffstat (limited to 'o3d/core/cross/message_queue.h')
| -rw-r--r-- | o3d/core/cross/message_queue.h | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/o3d/core/cross/message_queue.h b/o3d/core/cross/message_queue.h new file mode 100644 index 0000000..e32d471 --- /dev/null +++ b/o3d/core/cross/message_queue.h @@ -0,0 +1,251 @@ +/* + * Copyright 2009, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + + +// This file contains the declaration of the MessageQueue, the class which +// allows external code (clients) to connect via the IMC library to O3D +// (server) and issue calls to it. + +#ifndef O3D_CORE_CROSS_MESSAGE_QUEUE_H_ +#define O3D_CORE_CROSS_MESSAGE_QUEUE_H_ + +#include <vector> +#include "native_client/src/shared/imc/nacl_imc.h" +#include "core/cross/types.h" + +namespace o3d { + +class ServiceLocator; +class ObjectManager; + +// Structure keeping information about shared memory regions created on the +// request of a client connection. +typedef struct { + // Unique (to the MessageQueue object that created it) id of the shared + // memory buffer. + int buffer_id_; + // Handle to the shared memory. + nacl::Handle shared_memory_handle_; + // Address to which it maps in the local memory space. + void* mapped_address_; + // Size in bytes + int32 size_; +} SharedMemoryInfo; + +// The ConnectedClient class holds information about clients that have made +// contact with the this instance of the server. +class ConnectedClient { + public: + explicit ConnectedClient(nacl::Handle handle); + + ~ConnectedClient(); + + // Registers a newly created shared memory buffer with the client. + // Parameters: + // id - the unique id of the shared memory buffer. + // handle - the nacl handle to the shared memory. + // address - the beginning of the buffer in the local address space. + // size - the size of the buffer in bytes. + void RegisterSharedMemory(int id, + nacl::Handle handle, + void *address, + int32 size); + + // Returns the socket handle the client uses to talk to the server. + nacl::Handle client_handle() { return client_handle_; } + + // Returns the shared memory record that matches the given buffer id. + const SharedMemoryInfo* GetSharedMemoryInfo(int buffer_id) const; + + private: + // Handle of the socket the client uses. + nacl::Handle client_handle_; + + std::vector<SharedMemoryInfo> shared_memory_array_; +}; + + +// The MessageQueue class handles the communcation between external code and +// O3D. It provides methods for initializing the communcation channel +// as well as reading data from and writing data to it. It is currently using +// the NativeClient Inter-Module Communication (IMC) library. +class MessageQueue { + public: + enum MessageId { + INVALID_ID = 0, + HELLO, // Handshake between the client and the server + ALLOCATE_SHARED_MEMORY, // Request to allocate a shared memory buffer + UPDATE_TEXTURE2D, // Request to update a 2D texture bitmap + MAX_NUM_IDS, + + ID_FORCE_DWORD = 0x7fffffff // Forces a 32-bit size enum + }; + + // Creates a MessageQueue that is able to receive messages and execute calls + // to the given Client object. + explicit MessageQueue(ServiceLocator* service_locator); + + ~MessageQueue(); + + // Initializes the communcation channel. + // Returns: + // true if the channel was initialized successfully, false otherwise. + bool Initialize(); + + // Checks for new messages on the queue. If messages are found then it + // it processes them, otherwise it simply returns. + // Returns: + // true if there were no new messages or new messages were succesfully + // received. + bool CheckForNewMessages(); + + // Returns the socket address used by the message queue. + String GetSocketAddress() const; + + private: + // Processes a request from an already connected client. It parses the + // parameters provided in the message and executes the appropriate action. + // Parameters: + // client - pointer to the ConnectedClient the request came from. + // message_length - length of the received message in bytes. + // message_id - id of the request received by the message + // header - message header containing information about the received + // message. + // handles - the array of handles referenced by the header. + // Returns: + // true if the message is properly formed and is succesfully handled by the + // Client. + bool ProcessClientRequest(ConnectedClient* client, + int message_length, + MessageId message_id, + nacl::MessageHeader* header, + nacl::Handle* handles); + + // Processes the HELLO message, which initiates a new connection with a + // client. + // Parameters: + // header - message header containing information about the received + // message. + // handles - the array of handles referenced by the header. + // Returns: + // true if the new client connected successfully. + bool ProcessHelloMessage(nacl::MessageHeader* header, nacl::Handle* handles); + + // Processes a request by a connected client to allocate a shared memory + // buffer. The size of the requested buffer is determined from the data + // passed in the message. Once the memory is allocated, a message containting + // the shared memory handle is sent back to the client. + // Parameters: + // client - pointer to the ConnectedClient the request came from. + // message_length - length of the received message in bytes. + // message_id - id of the request received by the message + // header - message header containing information about the received + // message. + // handles - the array of handles referenced by the header. + // Returns: + // true if the message is properly formed and is succesfully handled by the + // Client. + bool ProcessAllocateSharedMemory(ConnectedClient* client, + int message_length, + MessageId message_id, + nacl::MessageHeader* header, + nacl::Handle* handles); + + // Processes a request by a connected client to update the contents of the + // bitmap corresponding to a Texture2D object. + // Parameters: + // client - pointer to the ConnectedClient the request came from. + // message_length - length of the received message in bytes. + // message_id - id of the request received by the message + // header - message header containing information about the received + // message. + // handles - the array of handles referenced by the header. + // Returns: + // true if the message is properly formed and is succesfully handled by the + // Client. + bool ProcessUpdateTexture2D(ConnectedClient* client, + int message_length, + MessageId message_id, + nacl::MessageHeader* header, + nacl::Handle* handles); + + // Sends a true of false (1 or 0) message using the given socket handle. + // Parameters: + // client_handle - handle of socket to send the response to. + // value - value to send. + // Returns: + // true on success. + bool SendBooleanResponse(nacl::Handle client_handle, bool value); + + // Checks a socket for a message without blocking waiting for one. If a + // valid message is found then it returns the message id. + // Parameters: + // socket - socket to check for messages. + // header - pointer to the message header used for receiving the message. + // message_id [out] - the ID of the message received. + // message_length [out] - the length of the message received. + // Returns: + // true if a message with a valid ID is found. true if no message is found. + // false in every other case. + bool ReceiveMessageFromSocket(nacl::Handle socket, + nacl::MessageHeader* header, + MessageId* message_id, + int* message_length); + + private: + + ServiceLocator* service_locator_; + ObjectManager* object_manager_; + + // A list of clients that are communicating via the message queue. + std::vector<ConnectedClient*> connected_clients_; + + // Handle of server (i.e. O3D) bound socket. + nacl::Handle server_socket_handle_; + + // Address of the server socket used by this MessageQueue. + nacl::SocketAddress server_socket_address_; + + // Stores the next available unique id that can be assigned to a newly + // created shared memory buffer. + int32 next_shared_memory_id_; + + // Stores the next available unique id for message queues. This allows + // us to create multiple instances of the MessageQueue, each with a unique + // address. + static int next_message_queue_id_; +}; + + +} // namespace o3d + + +#endif // O3D_CORE_CROSS_MESSAGE_QUEUE_H_ |