-- PacketStreamMgr.mesa (last edited by: Garlick on: January 23, 1981 4:17 PM) -- Function: The implementation module for the manager of Pilot Packet Streams. DIRECTORY CommunicationInternal USING [], CommFlags USING [doDebug], DriverDefs USING [Glitch], NetworkStream USING [], OISCP USING [uniqueAddress, unknownConnID], OISCPTypes USING [ConnectionID, WaitTime], PacketStream USING [ FailureReason, Handle, SuspendReason, ClassOfService, WaitTime, defaultWaitTime], PacketStreamInstance USING [Delete], PrincOpsUtils USING [GlobalFrame], Router USING [AssignDestinationRelativeOisAddress], NSAddress USING [NetworkAddress]; PacketStreamMgr: MONITOR IMPORTS PrincOpsUtils, DriverDefs, pktStrmInst: PacketStreamInstance, Router EXPORTS CommunicationInternal, NetworkStream, PacketStream = BEGIN OPEN Router, PacketStream; -- These variables must eventually live in outerspace so that multiple MDSs -- access the same packet stream variables. The module in the primary MDS will -- perform the initialization of the "globals", while the others will not. -- This module is a monitor in order to protect the value of spareConnectionID and the -- ConnectionTable. Some day the connection IDs in use will be remembered across wrap -- around. primaryMDS: PUBLIC BOOLEAN _ TRUE; -- we are in the primary MDS. infiniteWaitTime: PUBLIC WaitTime _ LAST[WaitTime]; initialSpareConnectionID: OISCPTypes.ConnectionID = [500]; -- monitor data -- connectionID parameters spareConnectionID: OISCPTypes.ConnectionID; -- connectionTable parameters and types ConnectionTable: ARRAY (0..maxConnectionNumber] OF ConnectionTableEntry; maxConnectionNumber: CARDINAL = 20; index: CARDINAL _ 0; ConnectionTableEntry: TYPE = RECORD [ rAddr: NSAddress.NetworkAddress, rConnID: OISCPTypes.ConnectionID]; -- various Glitches. ConnectionTableFull: ERROR = CODE; NotInConnectionTable: ERROR = CODE; ConnectionSuspended: PUBLIC ERROR [why: SuspendReason] = CODE; ConnectionFailed: PUBLIC SIGNAL [why: FailureReason] = CODE; AttentionTimeout: PUBLIC ERROR = CODE; -- Cool Procedures -- This procedure creates a packet stream instance. The local and remote addresses -- must be correctly specified, or else we pick defaults when possible. Make: PUBLIC PROCEDURE [ local, remote: NSAddress.NetworkAddress, localConnID, remoteConnID: OISCPTypes.ConnectionID, establishConnection: BOOLEAN, timeout: OISCPTypes.WaitTime _ defaultWaitTime, classOfService: ClassOfService _ bulk] RETURNS [psH: PacketStream.Handle] = BEGIN estdRemoteAddr: NSAddress.NetworkAddress; estdRemoteConnID: OISCPTypes.ConnectionID; newPktStrmInst: POINTER TO FRAME[PacketStreamInstance] _ NEW pktStrmInst; BEGIN ENABLE UNWIND => newPktStrmInst.Delete[]; -- If we do not have a local address we pick one with a network number that is a -- good way to get to the destinationand therefore a good way to get back to us! IF local = OISCP.uniqueAddress THEN local _ Router.AssignDestinationRelativeOisAddress[remote.net]; IF localConnID = OISCP.unknownConnID THEN localConnID _ GetUniqueConnectionID[]; [psH, estdRemoteAddr, estdRemoteConnID] _ START newPktStrmInst[ local, remote, localConnID, remoteConnID, establishConnection, timeout, classOfService]; InsertIntoConnectionTable[estdRemoteAddr, estdRemoteConnID]; END; END; -- Create -- This procedure deletes the specified packet stream instance. Destroy: PUBLIC PROCEDURE [psH: PacketStream.Handle] = BEGIN oldPktStrmInst: POINTER TO FRAME[PacketStreamInstance] _ LOOPHOLE[PrincOpsUtils.GlobalFrame[psH.get], POINTER]; remote: NSAddress.NetworkAddress _ oldPktStrmInst.remoteAddr; remoteConnID: OISCPTypes.ConnectionID _ oldPktStrmInst.remoteConnectionID; oldPktStrmInst.Delete[]; RemoveFromConnectionTable[remote, remoteConnID]; END; -- Delete -- This procedure returns a unique connection ID. Some day the active connection IDs -- in use will be kept around, so that on wrap around an unused ID will be assigned. GetUniqueConnectionID: ENTRY PROCEDURE RETURNS [iD: OISCPTypes.ConnectionID] = BEGIN iD _ spareConnectionID; IF (spareConnectionID _ [spareConnectionID + 1]) = OISCPTypes.ConnectionID[0] THEN spareConnectionID _ initialSpareConnectionID; END; -- GetUniqueConnectionID -- This procedure inserts a connection into the connectionTable. InsertIntoConnectionTable: PUBLIC ENTRY PROCEDURE [ remote: NSAddress.NetworkAddress, remoteConnID: OISCPTypes.ConnectionID] = BEGIN IF (index _ index + 1) > maxConnectionNumber THEN IF CommFlags.doDebug THEN DriverDefs.Glitch[ConnectionTableFull]; ConnectionTable[index] _ ConnectionTableEntry[remote, remoteConnID]; END; -- InsertIntoConnectionTable -- This procedure removes a connection from the connectionTable. RemoveFromConnectionTable: PUBLIC ENTRY PROCEDURE [ remote: NSAddress.NetworkAddress, remoteConnID: OISCPTypes.ConnectionID] = BEGIN i: CARDINAL; FOR i IN (0..index] DO IF ConnectionTable[i].rAddr.host = remote.host AND ConnectionTable[ i].rAddr.socket = remote.socket AND ConnectionTable[i].rConnID = remoteConnID THEN BEGIN ConnectionTable[i] _ ConnectionTable[index]; index _ index - 1; RETURN; END; ENDLOOP; IF CommFlags.doDebug THEN DriverDefs.Glitch[NotInConnectionTable]; END; -- RemoveFromConnectionTable -- This procedure checks if there is a similar connection in the connectionTable. ConnectionAlreadyThere: PUBLIC ENTRY PROCEDURE [ remote: NSAddress.NetworkAddress, remoteConnID: OISCPTypes.ConnectionID] RETURNS [BOOLEAN] = BEGIN i: CARDINAL; FOR i IN (0..index] DO IF ConnectionTable[i].rAddr.host = remote.host AND ConnectionTable[ i].rAddr.socket = remote.socket AND ConnectionTable[i].rConnID = remoteConnID THEN RETURN[TRUE]; ENDLOOP; RETURN[FALSE]; END; -- ConnectionAlreadyThere -- initialization IF primaryMDS THEN spareConnectionID _ initialSpareConnectionID; END. -- of PacketStreamMgr module LOG Time: January 23, 1981 4:17 PM By: Garlick Action: added classOfService to Make. J0p