desmoj.extensions.crossbar

Class MessageChannel<T extends SimProcess>

java.lang.Object

desmoj.core.simulator.NamedObject

desmoj.core.simulator.ModelComponent

desmoj.core.simulator.Reportable

desmoj.extensions.crossbar.MessageChannel<T>

Type Parameters:

T - Parameter restricting the types of processes which can wait on a MessageChannel.

public class MessageChannel<T extends SimProcess>
extends Reportable

Represents a message channel which resides on a MessageCrossbar. MessageChannels can only be used in conjunction with a message crossbar.

On the one hand MessageChannels allow for processes to wait for CrossbarMessages on them (passivating the process) and on the other hand they allow for processes to send CrossbarMessages to them. If a CrossbarMessage is received this leads to the immediate activation of all process waiting on the channel.

Version:

DESMO-J, Ver. 2.5.1c copyright (c) 2015

Author:

Malte Unkrig Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

See Also:

MessageCrossbar, CrossbarMessage

Method Summary

Modifier and Type	Method and Description
long	getDeliveredMessages()
java.lang.Object	getDirectProcessActivations()
long	getIndirectProcessActivations()
long	getInterruptedWaits()
long	getLostMessages()
long	getObservations() Returns the number of observations made by the reportable object.
long	getProcessActivations()
long	getReceivedMessages()
void	reset() Resets the counter for observations made by this reportable.
TimeInstant	resetAt() Shows the point in simulation time when the last reset of this reportable was made.
void	send(CrossbarMessage message) Sends the given CrossbarMessage to the channel, thereby activating all processes that are waiting on the channel.
CrossbarMessage	waitForMessage() Wait for a CrossbarMessage on this channel, thereby passivating the current process.
CrossbarMessage	waitForMessage(TimeInstant waitUntil) Wait for a CrossbarMessage on this channel, thereby passivating the current process.
CrossbarMessage	waitForMessage(TimeSpan maxWaitTime) Wait for a CrossbarMessage on this channel, thereby passivating the current process.

Methods inherited from class desmoj.core.simulator.Reportable

getCorrespondingSchedulable, getDescription, getReporter, incrementObservations, incrementObservations, reportIsOn, reportOff, reportOn, setCorrespondingSchedulable, setDescription, setReporter

Methods inherited from class desmoj.core.simulator.ModelComponent

current, currentEntity, currentEntityAll, currentEvent, currentModel, currentSimProcess, debugIsOn, debugOff, debugOn, getModel, isExperimentCompatible, isModelCompatible, presentTime, sendDebugNote, sendMessage, sendTraceNote, sendWarning, skipTraceNote, skipTraceNote, traceIsOn, traceOff, traceOn

Methods inherited from class desmoj.core.simulator.NamedObject

getName, getQuotedName, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

getDeliveredMessages

public long getDeliveredMessages()

Returns:

The number of delivered messages. A message is considered delivered if it was forwarded to at least one waiting process.

getDirectProcessActivations

public java.lang.Object getDirectProcessActivations()

Returns:

The number of process which were activated by a message directly received on this channel.

getIndirectProcessActivations

public long getIndirectProcessActivations()

Returns:

The number of process which were removed from this channel because they were activated (indirectly) by a message received on another channel.

getInterruptedWaits

public long getInterruptedWaits()

Returns:

The number of process which were interrupted while waiting on this channel because their max wait time was exceeded.

getLostMessages

public long getLostMessages()

Returns:

The number of message which were sent to this channel but couldn't be forwarded to a receiver because no process was waiting on the channel when the message was received.

getObservations

public long getObservations()

Description copied from class: Reportable

Returns the number of observations made by the reportable object.

Overrides:

getObservations in class Reportable

Returns:

The number of processes which have been handled by this message channel (meaning processes which entered the channel and also left it again).

getProcessActivations

public long getProcessActivations()

Returns:

The number of process which were removed from this channel because they were activated either by a message received directly on this channel or by a message received (indirectly) on another channel.

getReceivedMessages

public long getReceivedMessages()

Returns:

The number of messages which were sent to this channel.

reset

public void reset()

Description copied from class: Reportable

Resets the counter for observations made by this reportable. The point of simulation time this method was called will be stored and can be retrieved using method resetAt().

Overrides:

reset in class Reportable

resetAt

public TimeInstant resetAt()

Description copied from class: Reportable

Shows the point in simulation time when the last reset of this reportable was made.

Overrides:

resetAt in class Reportable

Returns:

TimeInstant : The point of simulation time of the last reset.

send

public void send(CrossbarMessage message)

Sends the given CrossbarMessage to the channel, thereby activating all processes that are waiting on the channel.

Parameters:

message - The message to send to the channel.

waitForMessage

public CrossbarMessage waitForMessage()
                               throws SuspendExecution

Wait for a CrossbarMessage on this channel, thereby passivating the current process. The process is not reactivated until a message is received.

Returns:

The message that was received.

Throws:

SuspendExecution

waitForMessage

public CrossbarMessage waitForMessage(TimeInstant waitUntil)
                               throws DelayedInterruptException,
                                      SuspendExecution

Wait for a CrossbarMessage on this channel, thereby passivating the current process. The process is not reactivated until a message is received. The parameter waitUntil specifies the point in time to which the current process will wait for a message. If no message is received before that time the process will be interrupted and a DelayedInterruptException will be thrown.

Parameters:

waitUntil - The point in time up to which the process will wait for a message before the waiting is aborted.

Returns:

The message that was received.

Throws:

DelayedInterruptException - The exception that indicates the process has reached its max wait time and has been interrupted.

SuspendExecution

waitForMessage

public CrossbarMessage waitForMessage(TimeSpan maxWaitTime)
                               throws DelayedInterruptException,
                                      SuspendExecution

Wait for a CrossbarMessage on this channel, thereby passivating the current process. The process is not reactivated until a message is received. The parameter maxWaitTime specifies the time the current process will wait for a message. If no message is received before the wait time has passed the process will be interrupted and a DelayedInterruptException will be thrown.

Parameters:

maxWaitTime - The time the process will wait for a message before the waiting is aborted.

Returns:

The message that was received.

Throws:

DelayedInterruptException - The exception that indicates the process has reached its max wait time and has been interrupted.

SuspendExecution