/* -*- C++ -*- */ // $Id$ // ============================================================================ // // = LIBRARY // ace // // = FILENAME // RMCast.h // // = AUTHOR // Carlos O'Ryan // // ============================================================================ #ifndef ACE_RMCAST_H #define ACE_RMCAST_H #include "ace/pre.h" #include "ace/OS.h" #include "RMCast_Export.h" #if !defined (ACE_LACKS_PRAGMA_ONCE) # pragma once #endif /* ACE_LACKS_PRAGMA_ONCE */ class ACE_Message_Block; class ACE_RMCast_Proxy; // LynxOS 3.X defines the following macro #if defined(MT_DATA) #undef MT_DATA #endif /* MT_DATA */ //! The RMCast namespace /*! Several simple data structures and enums are shared by all the RMCast components, this is the place where we put them by default. */ class ACE_RMCast_Export ACE_RMCast { public: //! The message types /*! Each message includes a type field in the header used by the receiver to correctly parse it. Classes with the same name as the message type describe the actual format of the message. */ enum Message_Type { // Sender initiated MT_POLL, MT_ACK_JOIN, MT_ACK_LEAVE, MT_DATA, // Receiver initiated MT_JOIN, MT_LEAVE, MT_ACK, MT_LAST }; //! Simle enum used to describe the state transitions for senders /*! State transition (and actions) for the senders. This configuration is pesimistic, any invalid message is cause enough to reclaim all the resources. This partially addresses situations where either accidentally or intentionally a sender is multicasting packets to the wrong group. NON_EXISTENT JOINED
------------------------------------------
POLL NON_EXISTENT NON_EXISTENT
Destroy Destroy

ACK NON_EXISTENT JOINED
Noop Process/Ack

JOIN JOINED NON_EXISTENT
Send/Join_Ack Send/Join_Ack

LEAVE NON_EXISTENT NON_EXISTENT
Send/Leave_Ack Send/Leave_Ack
Destroy

ACK_JOIN NON_EXISTENT NON_EXISTENT
Noop Destroy

ACK_LEAVE NON_EXISTENT NON_EXISTENT
Noop Destroy

SEND_DATA NON_EXISTENT NON_EXISTENT
Noop Destroy
 */ enum Sender_State { SS_NON_EXISTENT, SS_JOINED }; // These structures define the basic layout of the messages. //! This is the main message sent by senders /*! +---------+----------------------+
| 8 bits | DATA |
+---------+----------------------+
| 32 bits | sequence_number |
+---------+----------------------+
| 32 bits | message_size |
+---------+----------------------+
| 32 bits | fragment_offset |
+---------+----------------------+
? ? ? ? ? | 32 bits | payload_size |
? ? ? ? ? +---------+----------------------+
| | payload |
+---------+----------------------+
 */ struct Data { // Source ID is implicit in recvfrom()... ACE_UINT32 sequence_number; ACE_UINT32 total_size; ACE_UINT32 fragment_offset; // @@ TODO: we may want to add optional fields, such as: // - Polling clients for their status // - Sending the range of messages in the queue // - If we are using authentic group communication we may // piggyback the ACK / NAK messages ACE_Message_Block *payload; //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; /*! +---------+----------------------+
| 8 bits | MT_POLL |
+---------+----------------------+
 */ struct Poll { //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; //! Receivers accept new members using this message /*! +---------+----------------------+
| 8 bits | MT_ACK_JOIN |
+---------+----------------------+
| 32 bits | next_sequence_number |
+---------+----------------------+
 */ struct Ack_Join { ACE_UINT32 next_sequence_number; //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; //! Senders acknowledge when receivers try to leave /*! +---------+----------------------+
| 8 bits | ACK_LEAVE |
+---------+----------------------+
 */ struct Ack_Leave { //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; //! Provide feedback to the sender about messages received and sent //! so far. /*! * * This message is used to provide feedback information to senders. * It contains two sequence numbers: * - \param next_expected: is the sequence number of the next message * expected, i.e. (next_expected-1) is the last message received * without any losses before it. * - \param highest_received: is the highest sequence number among * all the messages successfully received. * In other words, all messages lost (if any) are in the range: * [next_expected,highest_received) * * * +---------+----------------------+
* | 8 bits | MT_ACK |
* +---------+----------------------+
* | 32 bits | next_expected |
* +---------+----------------------+
* | 32 bits | highest_received |
* +---------+----------------------+
* */ struct Ack { //! The last message received without any losses before it. ACE_UINT32 next_expected; //! The last message successfully received ACE_UINT32 highest_received; //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; //! Receivers send this message to indicate they want to join /* +---------+----------------------+
| 8 bits | MT_JOIN |
+---------+----------------------+
 */ struct Join { //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; //! Receivers send this message to disconnect gracefully /*! +---------+----------------------+
| 8 bits | MT_LEAVE |
+---------+----------------------+
 */ struct Leave { //! Pass the proxy source between layers ACE_RMCast_Proxy *source; }; }; #if defined (__ACE_INLINE__) #include "RMCast.i" #endif /* __ACE_INLINE__ */ #include "ace/post.h" #endif /* ACE_RMCAST_H */