The underlying peer-to-peer communications protocol may send multiple
`
`messages in a single message stream. The traditional technique for retrieving messages from
`
`a stream has been to repeatedly invoke an operating system routine to retrieve the next
`
`message in the stream. The retrieval of each message may require two calls to the operating
`
`system: one to retrieve the size of the next message and the other to retrieve the number of
`
`bytes indicated by the retrieved size. Such calls to the operating system can, however, be
`
`very slow in comparison to the invocations of local routines. To overcome the inefficiencies
`
`of such repeated calls, the broadcast technique in one embodiment, uses XDR to identify the
`
`message boundaries in a stream of messages. The broadcast technique may request the
`
`10
`
`operating system to provide the next, for example, 1,024 bytes from the stream?“ The
`broadcast technique can then repeatedly invoke the XDR routines to retrieve the messages
`
`and use the success or failure of each invocation to determine whether another block of 1,024
`
`bytes needs to be retrieved from the operating system. The invocation of XDR routines do
`
`not involve system calls and are thus more efi'icient than repeated system calls.
`
`15
`
`M-Regular
`
`In the embodiment described above, each fully connected computer has four
`
`20
`
`25
`
`internal connections. The broadcast technique can be used with other numbers of internal
`
`connections. For example, each computer could have 6, 8, or any even number of internal
`
`connections. As the number of internal connections increase, the diameter of the broadcast
`
`channel tends to decrease, and thus propagation time for a message tends to decrease. The
`
`time that it takes to connect a seeking computer to the broadcast channel may, however,
`
`increase as the number of internal connections increases. When the number of internal
`
`connectors is even,
`
`then the broadcast channel can be maintained as m-regular and
`
`m-connected (in the steady state).
`
`If the number of internal connections is odd, then when
`
`the broadcast channel has an odd number of computers connected, one of the computers will
`
`have less than that odd number of internal connections.
`
`In such a situation, the broadcast
`
`network is neither m-regular nor m-connected. When the next computer connects to the
`
`broadcast channel,
`
`it can again become m-regular and m-connected. Thus, with an odd
`
`number of internal connections, the broadcast channel toggles between being and not being
`m-regular and m-connected.
`
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`[03004-8001/Documa1t1268]
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`0274
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`BUNGIE - EXHIBIT 1002 Part 2 of 5
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`

`

`Components
`
`Figure 6 is a block diagram illustrating components of a computer that is
`
`connected to a broadcast charmel. The above description generally assumed that there was
`
`only one broadcast channel and that each computer had only one connection to that broadcast
`
`channel. More generally, a network of computers may have multiple broadcast channels,
`
`each computer may be connected to more than one broadcast channel, and each computer
`
`can have multiple connections to the same broadcast channel. The broadcast channel is well
`
`suited for computer processes (e.g., application programs) that execute collaboratively, such
`
`as network meeting programs. Each computer process can connect to one or more broadcast
`
`10
`
`' channels.
`
`The broadcast channels can be identified by channel
`
`type (e. g., application
`
`program channel instance that represents separate broadcast channels for that
`
`l5
`
`20
`
`channel type. When a process attempts to connect to a broadcast channel, it seeks a process
`
`currently connected to that broadcast channel that is executing on a portal computer. The
`
`seeking process identifies the broadcast channel by channel type and channel instance.
`
`Computer 600 includes multiple application programs 601 executing as
`
`separate processes. Each application program interfaces with a broadcaster component 602
`
`for each broadcast channel to which it is connected. The broadcaster component may be
`implement as an object that is instantiated within the process space of the application
`
`program. Alternatively, the broadcaster component may execute as a separate process or
`
`thread from the application program.
`
`In one embodiment,
`
`the broadcaster component
`
`provides functions (e.g., methods of class) that can be invoked by the application programs.
`
`The primary functions provided may include a connect function that an application program
`
`invokes passing an indication of the broadcast channel to which the application program
`
`wants to connect.
`
`The application program may provide a callback routine that
`
`the
`
`broadcaster component invokes to notify the application program that the connection has
`been completed, that is the process enters the fully connected state.
`The broadcaster
`
`component may also provide an acquire message function that the application program can
`invoke to retrieve the next message that is broadcast on the broadcast channel. Alternatively,
`the application program may provide a callback routine (which may be a virtual function
`provided by the application program) that the broadcaster component invokes to notify the
`application program that a broadcast message has been received.
`Each broadcaster
`
`30
`
`component allocates a call-in port using the hashing algorithm. When calls are answered at
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`10
`
`15
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`
`the call-in port, they are transferred to other ports that serve as the external and internal
`
`ports.
`
`The computers connecting to the broadcast channel may include a central
`
`processing unit, memory, input devices (e.g., keyboard and pointing device), output devices
`
`(e.g., display devices), and storage devices (e.g., disk drives). The memory and storage
`
`devices are computer-readable medium that may contain computer
`
`instructions that
`
`implement
`
`the broadcaster component.
`
`In addition,
`
`the data structures and message
`
`structures may be stored or transmitted via a signal transmitted on a computer-readable
`
`media, such as a communications link.
`
`Figure 7 is a block diagram illustrating the sub-components of the broadcaster
`
`component in one embodiment. The broadcaster component includes a connect component
`
`701, an external dispatcher 702, an internal dispatcher 703 for each internal connection, an
`
`acquire message component 704 and a broadcast component 712. The application program
`
`may provide a connect callback component 710 and a receive response component 711 that
`
`are invoked by the broadcaster component. The application program invokes the connect
`
`component to establish a connection to a designated broadcast channel.
`
`The connect
`
`component identifies the external port and installs the external dispatcher for handling
`
`messages that are received on the external port. The connect component invokes the seek
`
`portal computer component 705 to identify a portal computer that
`
`is connected to the
`
`broadcast channel and invokes the connect request component 706 to ask the portal computer
`
`(if fully connected) to select neighbor processes for the newly connecting process. The
`
`external dispatcher receives external messages, identifies the type of message, and invokes
`
`the appropriate handling routine 707. The internal dispatcher receives the internal messages,
`
`identifies the type of message, and invokes the appropriate handling routine 708. The
`
`received broadcast messages are stored in the broadcast message queue 709. The acquire
`
`message component
`is invoked to retrieve messages from the broadcast queue.
`broadcast component is invoked by the application program to broadcast messages in the
`broadcast channel.
`
`The
`
`The following tables list messages sent by the broadcaster components.
`
`[03004-8001m0mmmt1168]
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`

`EXTERNAL MESSAGES
`
`Message Type
`
`Description
`
`seeking_connection_call
`
`Indicates that a seeking process would like to know whether the
`receiving process is fully connected to the broadcast channel
`
`
`
`
`
`
`
`connection_request_call
`
`
`
`edge_proposal_call
`
`
`
`
`
`
`
`Indicates that the sending process would like the receiving
`process to initiate a connection of the sending process to the
`
`broadcast channel
`
`Indicates that the sending process is proposing an edge through
`which the receiving process can connect to the broadcast
`channel (i.e., edge pinning)
` Indicates that the sending process is proposing a port through
`port_connection_call
`
`which the receiving process can connect to the broadcast
`
`channel
`
`
`
`
`
`
`
`connected_stmt
`
`Indicates that the sending process is connected to the broadcast
`channel
`
`condition_repair_stmt
`
`Indicates that the receiving process should disconnect from one
`of its neighbors and connect to one of the processes involved in
`the neighbors with empty port condition
`
`INTERNAL MESSAGES
`
`
`
`
`
`
`
`
`Indicates a message that is being broadcast through the
`broadcast channel for the application programs
`
`Indicates that the designated process is looking for a port
`through which it can connect to the broadcast channel
`
`Indicates that the requesting process is looking for an edge
`through which it can connect to the broadcast channel
`
`Indicates whether the edge between this process and the
`sending neighbor has been accepted by the requesting
`Party
`
`Indicates to reset the estimated diameter to indicated
`diameter
`
`Indicates that the sending neighbor is disconnecting from
`the broadcast channel
`
`Indicates that neighbors with empty port condition have
`
`
`
` Message Type
`I broadcast_stmt
`
`
`I connection_port_search_stmt
`
`connection_edge_search_ch
`
`connection_edge_search_resp
`
`
`
`
`
`
`
`
`
`diameter reset strnt
`_
`_
`
`disconnect_stmt
`
`
`
`
`
`condition_check_stmt
`
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`

`

`condition_double_check_stmt
`
` — been detected
`
`
`Indicates that the neighbors with empty ports have the
`same set of neighbors
`Indicates that the broadcast channel is being shutdown
`
`
`
`
`Flow Diagrams
`
`Figures 8-34 are flow diagrams illustrating the processing of the broadcaster
`
`component in one embodiment. Figure 8 is a flow diagram illustrating the processing of the
`
`connect routine in one embodiment. This routine is passed a channel type (e.g., application
`
`name) and channel instance (e. g., session identifier), that identifies the broadcast channel to
`
`which this process wants to connect. The routine is also passed auxiliary information that
`
`includes the list of portal computers and a connection callback routine. When the connection
`
`is established, the connection callback routine is invoked to notify the application program.
`
`When this process invokes this routine, it is in the seeking connection state. When a portal
`
`computer is located that is connected and this routine connects to at least one neighbor, this
`
`process enters the partially connected state, and when the process eventually connects to four
`
`neighbors, it enters the fully connected state. When in the small regime, a fully connected
`process may have less than four neighbors.
`In block 801, the routine opens the call-in port
`through which the process is to communicate with other processes when establishing external
`
`and internal connections. The port is selected as the first available port using the hashing
`
`algorithm described above.
`
`In block 802, the routine sets the connect time to the current
`
`time. The connect time is used to identify the instance of the process that is connected
`
`through this external port. One process may connect to a broadcast channel of a certain
`
`channel type and channel instance using one call-in port and then disconnects, and another
`
`process may then connect to that same broadcast channel using the same call-in port. Before
`
`the other process becomes fully connected, another process may try to communicate with it
`
`thinking it is the fully connected old process.
`
`In such a case, the connect time can be used to
`
`In block 803, the routine invokes the seek portal computer routine
`identify this situation.
`passing the channel type and channel instance. The seek portal computer routine attempts to
`locate a portal computer through which this process can connect to the broadcast channel for
`
`the passed type and instance.
`
`In decision block 804, if the seek portal computer routine is
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`

`successful in locating a fully connected process on that portal computer, then the routine
`
`continues at block 805, else the routine returns an unsuccessful indication. In decision block
`
`805, if no portal computer other than the portal computer on which the process is executing
`
`was located, then this is the first process to fully connect to-broadcast channel and the
`
`routine continues at block 806, else the routine continues at block 808.
`
`In block 806, the
`
`routine invokes the achieve connection routine to change the state of this process to fully
`
`connected.
`
`In block 807, the routine installs the external dispatcher for processing messages
`
`received through this process’ external port for the passed channel type and channel instance.
`
`When a message is received through that external port, the external dispatcher is invoked.
`The routine then returns.
`In block 808, the routine installs an external dispatcher.
`In block
`
`10
`
`809,
`
`the routine invokes the connect request routine to initiate the process of identifying
`
`15
`
`20
`
`25
`
`30
`
`neighbors for the seeking computer. The routine then returns.
`
`Figure 9 is a flow diagram illustrating the processing of the seek portal
`
`computer routine in one embodiment. This routine is passed the channel type and channel
`
`instance of the broadcast channel to which this process wishes to connect. This routine, for
`
`each search depth (e.g., port number), checks the portal computers at that search depth.
`
`If a
`
`portal computer is located at that search depth with a process that is fully connected to the
`
`broadcast channel, then the routine returns an indication of success.
`
`In blocks 902-911, the
`
`routine loops selecting each search depth until a process is located. In block 902, the routine
`
`selects the next search depth using a port number ordering algorithm.
`
`In decision block 903,
`
`if all the search depths have already been selected during this execution of the loop, that is
`
`for the currently selected depth, then the routine returns a failure indication, else the routine
`
`continues at block 904.
`
`In blocks 904-911, the routine loops selecting each portal computer
`
`and determining whether a process of that portal computer is connected to (or attempting to
`
`connect to) the broadcast channel with the passed channel type and channel instance.
`
`In
`
`block 904, the routine selects the next portal computer.
`
`In decision block 905, if all the
`
`portal computers have already been selected, then the routine loops to block 902 to select the
`
`next search depth, else the routine continues at block 906.
`
`In block 906, the routine dials the
`
`In decision block
`selected portal computer through the port represented by the search depth.
`907, if the dialing was successful, then the routine continues at block 908, else the routine
`loops to block 904 to select the next portal computer. The dialing will be successful if the
`dialed port is the call-in port of the broadcast channel of the passed channel type and channel
`[03004-800lfl)ocumnl.268]
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`

`

`instance of a process executing on that portal computer.
`
`In block 908, the routine invokes a
`
`contact process routine, which contacts the answering process of the portal computer through
`
`the dialed port and determines whether that process is fully connected to the broadcast
`
`channel.
`
`In block 909, the routine hangs up on the selected portal computer.
`
`In decision
`
`block 910, if the answering process is fully connected to the broadcast channel,
`
`then the
`
`routine returns a success indicator, else the routine continues at block 911.
`
`In block 911, the
`
`routine invokes the check for external call routine to detenninewhether an external call has
`
`been made to this process as a portal computer and processes that call. The routine then
`
`loops to block 904 to select the next portal computer.
`
`Figure 10 is a flow diagram illustrating the processing of the contact process
`
`routine in one embodiment. This routine determines whether the process of the selected
`
`portal computer that answered the call-in to the selected port is fully connected to the
`
`broadcast channel.
`
`In block 1001,
`
`the routine sends an external message
`
`(i.e.,
`
`seeking_connection_call) to the answering process indicating that a seeking process wants to
`
`know whether the answering process is fully connected to the broadcast channel.
`
`In block
`
`1002, the routine receives the external response message from the answering process.
`
`In
`
`decision block 1003,
`
`if the external
`
`response message is successfully received (i.e.,
`
`seeking_connection_resp), then the routine continues at block 1004, else the routine retums.
`
`Wherever the broadcast component requests to receive an external message, it sets a time out
`
`period.
`
`If the external message is not received within that time out period, the broadcaster
`
`component checks its own call-in port to see if another process is calling it.
`
`In particular, the
`
`dialed process may be calling the dialing process, which may result in a deadlock situation.
`
`The broadcaster component may repeat the receive request several times.
`
`If the expected
`
`message is not received, then the broadcaster component handles the error as appropriate.
`
`In
`
`decision block 1004, if the answering process indicates in its response message that it is fully
`connected to the broadcast channel, then the routine continues at block 1005, else the routine
`
`In block 1005, the routine adds the selected portal computer to a
`continues at block 1006.
`list of connected portal computers and then returns.
`In block 1006, the routine adds the
`
`answering process to a list of fellow seeking processes and then returns.
`
`Figure 11 is a flow diagram illustrating the processing of the connect request
`routine in one embodiment. This routine requests a process of a portal computer that was
`identified as being fully connected to the broadcast channel to initiate the connection of this
`[03004-8001/Documanl168]
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`
`0280
`
`0280
`
`

`

`process to the broadcast channel.
`
`In decision block 1101, if at least one process of a portal
`
`computer was located that is fully connected to the broadcast channel,
`
`then the routine
`
`continues at block 1103, else the routine continues at block 1102. A process of the portal
`
`computer may no longer be in the list if it recently disconnected from the broadcast channel.
`
`In one embodiment, a seeking computer may always search its entire search depth and find
`
`multiple portal computers through which it can connect to the broadcast channel.
`
`In block
`
`1102, the routine restarts the process of connecting to the broadcast channel and returns.
`
`In
`
`block 1103, the routine dials the process of one of the found portal computers through the
`
`call-in port.
`
`In decision block 1104, if the dialing is successful, then the routine continues at
`
`block 1105, else the routine continues at block 1113. The dialing may be unsuccessful if, for
`
`example, the dialed process recently disconnected from the broadcast channel.
`
`In block
`
`1105, the routine sends an external message to the dialed process requesting a connection to
`
`the broadcast channel (i. e., connection_request_call).
`
`In block 1106, the routine receives the
`
`response message (i.e., connection_request__resp).
`
`In decision block 1107, if the response
`
`message is successfully received, then the routine continues at block 1108, else the routine
`
`continues at block 1113.
`
`In block 1108, the routine sets the expected number of holes (i.e.,
`
`empty internal connections) for this process based on the received response. When in the
`
`large regime, the expected number of holes is zero. When
`
`the small regime, the expected
`
`number of holes varies from one to three.
`
`In block 1109, the routine sets the estimated
`
`diameter of the broadcast channel based on the received response.
`
`In decision block 1111, if
`
`the dialed process is ready to connect to this process as indicated by the response message,
`
`then the routine continues at block 1112, else the routine continues at block 1113.
`
`In block
`
`1112,
`
`the routine invokes the add neighbor routine to add the answering process as a
`
`neighbor to this process. This adding of the answering process typically occurs when the
`
`broadcast channel is in the small regime. When in the large regime, the random walk search
`
`for a neighbor is performed.
`
`In block 1113, the routine hangs up the external connection
`
`with the answering process computer and then retums.
`
`Figure 12 is a flow diagram of the processing of the check for external call
`
`routine in one embodiment. This routine is invoked to identify whether a fellow seeking
`process is attempting to establish a connection to the broadcast channel through this process.
`In block 1201, the routine attempts to answer a call on the call-in port.
`In decision block
`
`1202, if the answer is successful, then the routine continues at block 1203, else the routine
`[03004-8001/Documem1268]
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`
`0281
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`0281
`
`

`

`returns.
`
`In block 1203, the routine receives the external message from the external port.
`
`In
`
`decision block 1204, if the type of the message indicates that a seeking process is calling
`
`(i.e., seeking_connection_call), then the routine continues at block 1205, else the routine
`
`returns. In block 1205, the routine sends an external message (i. e., seeking_connection_resp)
`
`to the other seeking process indicating that this process is also is seeking a connection.
`
`In
`
`decision block 1206, if the sending of the external message is successful, then the routine
`
`continues at block 1207, else the routine returns.
`
`In block 1207, the routine adds the other
`
`seeking process to a list of fellow seeking processes and then returns. This list may be used
`
`if this process can find no process that is fully connected to the broadcast channel.
`
`In which
`
`case,
`
`this process may check to see if any fellow seeking process were successful
`
`in
`
`connecting to the broadcast channel. For example, a fellow seeking process may become the
`
`first process fully connected to the broadcast channel.
`
`Figure 13 is a flow diagram of the processing of the achieve connection routine
`
`in one embodiment. This routine sets the state of this process to fully connected to the
`
`broadcast charmel and invokes a callback routine to notify the application program that the
`
`process is now fully connected to the requested broadcast channel.
`
`In block 1301, the
`
`routine sets the connection state of this process to fully connected.
`
`In block 1302, the
`
`routine notifies fellow seeking processes that it is fully connected by sending a connected
`
`external message to them (i.e., connected_stmt).
`
`In block 1303,
`
`the routine invokes the
`
`connect callback routine to notify the application program and then returns.
`
`Figure 14 is a flow diagram illustrating the processing of the external
`
`dispatcher routine in one embodiment. This routine is invoked when the external port
`
`receives a message. This routine retrieves the message, identifies the external message type,
`
`and invokes the appropriate routine to handle that message. This routine loops processing
`
`each message until all the received messages have been handled.
`
`In block 1401, the routine
`
`In decision
`answers (e.g., picks up) the external port and retrieves an external message.
`block 1402, if a message was retrieved, then the routine continues at block 1403, else the
`routine hangs up on the external port in block 1415 and returns.
`In decision block 1403, if
`
`IO
`
`15
`
`20
`
`30
`
`the message type is for a process seeking a connection (i.e., seeking_connection_call), then
`the routine invokes the handle seeking connection call routine in block 1404, else the routine
`continues at block 1405.
`In decision block 1405, if the message type is for a connection
`
`request call (i. e., connection_request_call), then the routine invokes the handle connection
`-29-
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`
`

`

`request call routine in block 1406, else the routine continues at block 1407.
`
`In decision
`
`block 1407, if the message type is edge proposal call (1'.e., edge_proposal_call), then the
`
`routine invokes the handle edge proposal call routine in block 1408, else the routine
`
`continues at block 1409.
`
`In decision block 1409, if the message type is port connect call
`
`(i. e., port_c’onnect_call), then the routine invokes the handle port connection call routine in
`
`block 1410, else the routine continues at block 1411.
`
`In decision block 1411, if the message
`
`type is a connected statement (i.e., connected_stmt),
`
`the routine invokes the handle
`
`connected statement in block 1112, else the routine continues at block 1212.
`
`In decision
`
`block 1412, if the message type is a condition repair statement (i.e., condition_repair_stmt),
`then the routine invokes the handle condition repair routine in block 1413, else the routine
`
`10
`
`loops to block 1414 to process the next message.”After each handling routine is invoked, the
`
`routine loops to block 1414.
`
`In block 1414, the routine hangs up on the external port and
`
`continues at block 1401 to receive the next message.
`
`l5
`
`20
`
`Figure 15 is a flow diagram illustrating the processing of the handle seeking
`
`connection call routine in one embodiment. This routine is invoked when a seeking process
`
`is calling to identify a portal computer through which it can connect to the broadcast channel.
`
`In decision block 1501, if this process is currently fully connected to the broadcast channel
`
`identified in the message, then the routine continues at block 1502, else the routine continues
`
`at block 1503.
`
`In block 1502, the routine sets a message to indicate that this process is fully
`
`connected to the broadcast channel and continues at block 1505.
`
`In block 1503, the routine
`
`sets a message to indicate that this process is not fully connected.
`
`In block 1504, the routine
`
`adds the identification of the seeking process to a list of fellow seeking processes.
`
`If this
`
`process is not fully connected, then it is attempting to connect to the broadcast channel.
`
`In
`
`block 1505, the routine sends the external message response (i.e., seeking_connection_resp)
`
`to the seeking process and then returns.
`
`Figure 16 is a flow diagram illustrating processing of the handle connection
`
`request call routine in one embodiment. This routine is invoked when the calling process
`
`wants this process to initiate the connection of the process to the broadcast channel. This
`
`30
`
`routine either allows the calling process to establish an internal connection with this process
`(e. g., if in the small regime) or starts the process of identifying a process to which the calling
`process can connect.
`In decision block 1601, if this process is currently fully connected to
`the broadcast channel, then the routine continues at block 1603, else the routine hangs up on
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`the extemal port in block 1602 and returns.
`
`In block 1603, the routine sets the number of
`
`holes that the calling process should expect in the response message.
`
`In block 1604, the
`
`routine sets the estimated diameter in the response message.
`
`In block 1605,
`
`the routine
`
`indicates whether this process is ready to connect to the calling process. This process is
`
`ready to connect when the number of its holes is greater than ‘zero and the calling process is
`
`not a neighbor of this process.
`I
`that
`is
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`external message
`
`In block 1606, the routine sends to the calling process an
`the
`(i.e.,
`
`request
`
`call
`
`responsive
`
`to
`
`connection
`
`10
`
`15
`
`20
`
`25
`
`30
`
`connection_request_resp).
`
`In block 1607, the routine notes the number of holes that the
`
`calling process needs to fill as indicated in the request message.
`
`In decision block 1608, if
`
`this process is ready to connect to the calling process, then the routine continues at block
`
`In block 1609, the routine invokes the add
`1609, else the routine continues at block 1611.
`neighbor routine to add the calling process as a neighbor.
`In block 1610,
`the routine
`
`decrements the number of holes that the calling process needs to fill and continues at block
`
`1611.
`
`In block 1611, the routine hangs up on the external port.
`
`In decision block 1612, if
`
`this process has no holes or the estimated diameter is greater than one (i.e., in the large
`
`regime), then the routine continues at block 1613, else the routine continues at block 1616.
`
`In blocks 1613-1615, the routine loops forwarding a request for an edge through which to
`
`connect to the calling process to the broadcast channel. One request is forwarded for each
`
`pair of holes of the calling process that needs to be filled.
`
`In decision block 1613, if the
`
`number of holes of the calling process to be filled is greater than or equal to two, then the
`
`routine continues at block 1614, else the routine continues at block 1616.
`
`In block 1614, the
`
`routine invokes the forward connection edge search routine. The invoked routine is passed
`
`to an indication of the calling process and the random walk distance.
`
`In one embodiment, the
`
`distance is twice in the estimated diameter of the broadcast channel.
`
`In block 1614, the
`
`routine decrements the holes left to fill by two and loops to block 1613.
`
`In decision block
`
`1616, if there is still a hole to fill, then the routine continues at block 1617, else the routine
`
`returns.
`In block 1617, the routine invokes the fill hole routine passing the identification of
`the calling process. The fill hole routine broadcasts a connection port search statement (i.e.,
`connection_port_search_stmt) for a hole of a connected process through which the calling
`process can connect to the broadcast channel. The routine then returns.
`
`Figure 17 is a flow diagram illustrating the processing of the add neighbor
`routine in one embodiment. This routine adds the process calling on the external port as a
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`neighbor to this process.
`
`In block‘1701, the routine identifies the calling process on the
`
`external port.
`
`In block 1702, the routine sets a flag to indicate that the neighbor has not yet
`
`received the broadcast messages from this process. This flag is used to ensure that there are
`
`no gaps in the messages initially sent to the new neighbor. The external port becomes the
`
`internal port for this connection.
`
`In decision block 1703, if this process is in the seeking
`
`connection state,
`
`then this process is connecting to its first neighbor and the routine
`
`continues at block 1704, else the routine continues at block 1705.
`
`In block 1704, the routine
`
`sets the connection state of this process to partially connected.
`adds the calling process to the list of neighbors of this process.
`
`In block 1705, the routine
`In block 1706, the routine
`
`installs an internal dispatcher for the new neighbor. The internal dispatcher is invoked when
`
`a message is received from that new neighbor through the internal port of that new neighbor.
`
`In decision block 1707, if this process buffered up messages while not fully connected, then
`
`the routine continues at block 1708, else the routine continues at block 1709.
`
`In one
`
`embodiment, a process that is partially connected may buffer the messages that it receives
`
`through an internal connection so that it can send these messages as it connects to new
`
`neighbors.
`
`In block 1708,
`
`the routine sends the buffered messages to the new neighbor
`
`through the internal port.
`
`In decision block 1709, if the number of holes of this process
`
`equals the expected number of holes, then this process is fully connected and the routine
`
`continues at block 1710, else the routine continues at block 1711.
`
`In block 1710, the routine
`
`invokes the achieve connected routine to indicate that this process is fully connected.
`
`In
`
`decision block 1711,
`
`if the number of holes for this process is zero,
`
`then the routine
`
`In block 1712, the routine deletes any
`continues at block 1712, else the routine returns.
`pending edges and then returns. A pending edge is an edge that has been proposed to this
`process for edge pinning, which in this case is no longer needed.
`
`Figure 18 is a flow diagram illustrating the processing of the forward
`connection edge search routine in one embodiment. This routine is responsible for passing
`along a request to connect a requesting p