TAO_ECG_CDR_Message_Receiver Class Reference

Receives UDP and Multicast messages. More...

#include <ECG_CDR_Message_Receiver.h>

Collaboration diagram for TAO_ECG_CDR_Message_Receiver:

Classes
struct	Mcast_Header
	Helper for decoding, validating and storing mcast header. More...
class	Requests

Public Member Functions
	TAO_ECG_CDR_Message_Receiver (CORBA::Boolean check_crc)
	Initialization and termination methods.
	~TAO_ECG_CDR_Message_Receiver ()
void	init (TAO_ECG_Refcounted_Endpoint ignore_from)
void	shutdown ()
int	handle_input (ACE_SOCK_Dgram &dgram, TAO_ECG_CDR_Processor *cdr_processor)

Static Public Attributes
static TAO_ECG_UDP_Request_Entry	Request_Completed_

Private Types
enum	{ ECG_DEFAULT_MAX_FRAGMENTED_REQUESTS = 1024 , ECG_DEFAULT_FRAGMENTED_REQUESTS_MIN_PURGE_COUNT = 32 }
typedef ACE_Hash_Map_Manager< ACE_INET_Addr, Requests *, ACE_Null_Mutex >	Request_Map

Private Member Functions
int	mark_received (const ACE_INET_Addr &from, CORBA::ULong request_id)
int	process_fragment (const ACE_INET_Addr &from, const Mcast_Header &header, char *data_buf, TAO_ECG_CDR_Processor *cdr_processor)
Request_Map::ENTRY *	get_source_entry (const ACE_INET_Addr &from)

Private Attributes
TAO_ECG_Refcounted_Endpoint	ignore_from_
	Ignore any events coming from this IP address.
Request_Map	request_map_
size_t	max_requests_
	Serializes use of <request_map_>.
size_t	min_purge_count_
CORBA::Boolean	check_crc_
	Flag to indicate whether CRC should be computed and checked.

Detailed Description

Receives UDP and Multicast messages.

Todo

Update class documentation below.

  5)  Make status array size and purge_count configurable.

This class receives UDP and Multicast message fragments, assembles them (described in detail below), and passes complete messages in the form of cdr streams to the calling classes.

This class is used by various Gateway classes (Senders/Receivers) responsible for federating Event Channels with UDP/Mcast.

= REASSEMBLY Fragmentation is described in ECG_CDR_Message_Sender.h Whenever an incomplete fragment is received (one with fragment_count > 1) we allocate an entry for the message in an map indexed by (host,port,request_id). The entry contains the buffer, a bit vector to keep track of the fragments received so far, and a timeout counter. This timeout counter is set to 0 on each (new) fragment arrival, and incremented on a regular basis. If the counter reaches a maximum value the message is dropped. Once all the fragments have been received the message is sent up to the calling classes, and the memory reclaimed.

Member Typedef Documentation

Request_Map

typedef ACE_Hash_Map_Manager<ACE_INET_Addr, Requests*, ACE_Null_Mutex> TAO_ECG_CDR_Message_Receiver::Request_Map

private

Member Enumeration Documentation

anonymous enum

anonymous enum

private

Enumerator
ECG_DEFAULT_MAX_FRAGMENTED_REQUESTS
ECG_DEFAULT_FRAGMENTED_REQUESTS_MIN_PURGE_COUNT

Constructor & Destructor Documentation

TAO_ECG_CDR_Message_Receiver()

TAO_ECG_CDR_Message_Receiver::TAO_ECG_CDR_Message_Receiver

(

CORBA::Boolean

check_crc

)

Initialization and termination methods.

~TAO_ECG_CDR_Message_Receiver()

TAO_ECG_CDR_Message_Receiver::~TAO_ECG_CDR_Message_Receiver

(

)

Member Function Documentation

get_source_entry()

TAO_ECG_CDR_Message_Receiver::Request_Map::ENTRY * TAO_ECG_CDR_Message_Receiver::get_source_entry ( const ACE_INET_Addr & from )

private

handle_input()

int TAO_ECG_CDR_Message_Receiver::handle_input	(	ACE_SOCK_Dgram &	dgram,
		TAO_ECG_CDR_Processor *	cdr_processor )

Main method: read the data from dgram and either pass ready data to cdr_processor or update the <request_map_> if the request is not yet complete. Returns 1 if data was read successfully and accepted by <cdr_processor> without errors. Returns 0 if there were no errors, but no data has been passed to <cdr_processor>, either due to request being incomplete (not all fragments received), or it being a duplicate. Returns -1 if there were errors.

init()

void TAO_ECG_CDR_Message_Receiver::init

(

TAO_ECG_Refcounted_Endpoint

ignore_from

)

Parameters

ignore_from

Endpoint used to remove events generated by the same process.

mark_received()

int TAO_ECG_CDR_Message_Receiver::mark_received ( const ACE_INET_Addr & from, CORBA::ULong request_id )

private

Returns 1 on success, 0 if <request_id> has already been received or is below current request range, and -1 on error.

process_fragment()

int TAO_ECG_CDR_Message_Receiver::process_fragment ( const ACE_INET_Addr & from, const Mcast_Header & header, char * data_buf, TAO_ECG_CDR_Processor * cdr_processor )

private

Returns 1 if complete request is received and <event> is populated, 0 if request has only partially been received or is a duplicate, and -1 on error.

shutdown()

void TAO_ECG_CDR_Message_Receiver::shutdown

(

)

Member Data Documentation

check_crc_

CORBA::Boolean TAO_ECG_CDR_Message_Receiver::check_crc_

private

Flag to indicate whether CRC should be computed and checked.

ignore_from_

TAO_ECG_Refcounted_Endpoint TAO_ECG_CDR_Message_Receiver::ignore_from_

private

Ignore any events coming from this IP address.

max_requests_

size_t TAO_ECG_CDR_Message_Receiver::max_requests_

private

Serializes use of <request_map_>.

Size of a fragmented requests array, i.e., max number of partially received requests kept at any given time per source.

min_purge_count_

size_t TAO_ECG_CDR_Message_Receiver::min_purge_count_

private

Minimum number of requests purged from a fragmented requests array when the range of requests represented there needs to be shifted.

Request_Completed_

TAO_ECG_UDP_Request_Entry TAO_ECG_CDR_Message_Receiver::Request_Completed_

static

Represents any request that has been fully received and serviced, to simplify the internal logic.

request_map_

Request_Map TAO_ECG_CDR_Message_Receiver::request_map_

private

The map containing all the incoming requests which have been partially received.

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The documentation for this class was generated from the following files:

• ECG_CDR_Message_Receiver.h
• ECG_CDR_Message_Receiver.cpp