Package uk.ac.manchester.spinnaker.connections

Class SCPConnection

java.lang.Object

uk.ac.manchester.spinnaker.connections.UDPConnection<SDPMessage>

uk.ac.manchester.spinnaker.connections.SDPConnection

uk.ac.manchester.spinnaker.connections.SCPConnection

All Implemented Interfaces:

Closeable, AutoCloseable, Connection, SCPSenderReceiver

Direct Known Subclasses:

DelegatingSCPConnection

public class SCPConnection
extends SDPConnection
implements SCPSenderReceiver

An SDP connection to talk SCP (SpiNNaker Control Protocol) to SC&MP on a SpiNNaker system, and to the cores managed by it. In general, an SCPConnection is thread safe when used via a TxrxProcess, but not all operations that can be invoked that way are; flood-fills of binaries are particularly known to be only safe to do strictly one at a time and with no other traffic.

Nested Class Summary

Nested classes/interfaces inherited from class uk.ac.manchester.spinnaker.connections.UDPConnection

UDPConnection.TrafficClass

Constructor Summary

Constructors

Modifier	Constructor	Description
	SCPConnection(HasChipLocation chip, InetAddress localHost, Integer localPort, InetAddress remoteHost)	Create a connection to a particular instance of SCAMP.
protected	SCPConnection(HasChipLocation chip, InetAddress localHost, Integer localPort, InetAddress remoteHost, int remotePort)	Create a connection to a particular instance of SCAMP.

Method Summary

Modifier and Type	Method	Description
protected final void	closeAndLogNoExcept()	Close this connection, logging failures instead of throwing.
void	closeEventually()	Close this connection eventually.
final SCPResultMessage	receiveSCPResponse(int timeout)	Receives an SCP response from this connection.
void	send(ByteBuffer requestData, int seq)	Send a request that expects a response to be appropriately directed to the thread that is calling this method.
String	toString()

Methods inherited from class uk.ac.manchester.spinnaker.connections.SDPConnection

getChip, receiveMessage, send, setChip

Methods inherited from class uk.ac.manchester.spinnaker.connections.UDPConnection

close, doReceive, doReceiveWithAddress, doSend, doSendTo, getLocalAddress, getLocalIPAddress, getLocalPort, getRemoteAddress, getRemoteIPAddress, getRemotePort, isClosed, isConnected, receive, receive, receiveMessage, receiveWithAddress, send, send, sendPortTriggerMessage, sendTo, sendTo, sendTo, setInUse, setNotInUse, setReceivePacketSize

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.io.Closeable

close

Methods inherited from interface uk.ac.manchester.spinnaker.connections.model.Connection

convertTimeout, getLocalIPAddress, getLocalPort, getRemoteIPAddress, getRemotePort, isClosed, isConnected, receive, receiveWithAddress, send, sendTo

Methods inherited from interface uk.ac.manchester.spinnaker.connections.model.SCPSenderReceiver

getChip, getSCPData, receiveSCPResponse, send

Constructor Details

SCPConnection

public SCPConnection(HasChipLocation chip,
 InetAddress localHost,
 Integer localPort,
 InetAddress remoteHost)
              throws IOException

Create a connection to a particular instance of SCAMP.

Parameters:

chip - The location of the chip on the board with this remoteHost

localHost - The optional host of the local interface to listen on; use null to listen on all local interfaces.

localPort - The optional local port to listen on; use null to pick a random port.

remoteHost - The remote host to send messages to.

Throws:

IOException - If anything goes wrong with socket setup.

SCPConnection

protected SCPConnection(HasChipLocation chip,
 InetAddress localHost,
 Integer localPort,
 InetAddress remoteHost,
 int remotePort)
                 throws IOException

Create a connection to a particular instance of SCAMP. Can use a specified local network interface.

Parameters:

chip - The location of the chip on the board with this remoteHost

localHost - The optional host of the local interface to listen on; use null to listen on all local interfaces.

localPort - The optional local port to listen on; use null to pick a random port.

remoteHost - The remote host to send messages to.

remotePort - The optional remote port number to send messages to. If null, the default remote port is used.

Throws:

IOException - If anything goes wrong with socket setup.

Method Details

receiveSCPResponse

public final SCPResultMessage receiveSCPResponse(int timeout)
                                          throws IOException,
InterruptedException

Receives an SCP response from this connection. Blocks until a message has been received, or a timeout occurs.

This is tricky code because there can be multiple threads using a connection at once and we need to direct responses to the threads that originated the requests that the responses match to. A consequence of this is that it is possible for the wait for a message to be longer than the timeout given; that will occur when the current thread keeps receiving messages for other threads.

Specified by:

receiveSCPResponse in interface SCPSenderReceiver

Parameters:

timeout - The time in milliseconds to wait for the message to arrive, or until the connection is closed.

Returns:

The SCP result, the sequence number, and the data of the response. The buffer pointer will be positioned at the point where the payload starts.

Throws:

IOException - If there is an error receiving the message

SocketTimeoutException - If there is a timeout before a message is received

InterruptedException - If communications are interrupted.

closeEventually

public void closeEventually()

Close this connection eventually. The close might not happen immediately.

closeAndLogNoExcept

protected final void closeAndLogNoExcept()

Close this connection, logging failures instead of throwing.

Core of implementation of closeEventually().

send

public void send(ByteBuffer requestData,
 int seq)
          throws IOException

Description copied from interface: SCPSenderReceiver

Send a request that expects a response to be appropriately directed to the thread that is calling this method.

Specified by:

send in interface SCPSenderReceiver

Parameters:

requestData - The message data to send.

seq - The sequence number to come in the response.

Throws:

IOException - If there is an error sending the message

See Also:

• Connection.send(ByteBuffer)

toString

public String toString()

Overrides:

toString in class UDPConnection<SDPMessage>