Module 6 - Activity Diagram Part 2

Question 1

what kind of model element is Enter Final Orbit?

Answer 1

Call behavior action

the Enter final orbit is calling a behavior that has been defined in the model .

Name : Behavior

there are three kinds of behaviors
1. activity
2. state machine
3. Interaction

Question 2

Which kind of action represents a behavioral decomposition

call behavior action or send signal action ?

Answer 2

Call behavior action

It represents a defined behavior in the model

Question 3

rake symbols are displayed when one activity calling another _____

Answer 3

activity

why is there a special notation ? the rake symbol is used anywhere that the modeler wants to indicate hierarchical representation

Question 4

This call behavior is synchronous , the action that calls fire thruster waits for it to finish executing then the action that calls it finishes executing then produces a _______

Answer 4

control token

notes : call behavior actions can call a behavior sync and asycn , its a checkbox in the specifications in cameo

when the action comes to an end , it produces a control token. It calls the behavior fire thruster to start its execution.

Question 5

what kind of action is this ?

Answer 5

send signal action

Question 6

three criteria that must be satisfied ? what does the action require to start executing ?

1. the activity that owns the action is currently executing
2. a control token arrives on each of the incoming control flows
3. a sufficient number of object tokens arrive on ___

Answer 6

each of the incoming object flows to meet the min multiplicity of the respective pin

Question 7

key idea of a send signal action

send signal sends an instance of a signal to a target object to asynchronously trigger a behavior in that target object , then that send signal action ______

Answer 7

terminates

Question 8

the send signal action asynchronously generates and send a signal once the

Answer 8

currentRadiusOrbit token arrives

Question 9

Review of a signal
- signals are elements of definition , it defines something
- a signal defines an asynch event that could occur in time.

Answer 9

• once a signal is defined there could be multiple occurrences/ instances of that signal sent and received

Question 10

a reception would be triggered by an arrival of a matching _____
a reception can only be invoked asynchronously

Answer 10

signal

Question 11

what is analogTempDataSampled ?

Answer 11

a reception

the signal also matches the receptions name

Question 12

signals and receptions are always ( fire and forget)
receptions are behaviors that can only behave

Answer 12

asynchronous

Question 13

a send signal action models the sending of an the name of the ________ being sent

Answer 13

name of the signal being sent

Question 14

when a signal arrive
1) can trigger a matching reception to trigger a new behavior
2) can also trigger an accept event ________
3) when a signal instance arrives it can also trigger a transition in a state machine behavior

Answer 14

action

an accept event action waits for an event to arrive , then it will execute

Question 15

which is the client ?

which is the target ?

Answer 15

send signal action is the client

accept event action is the target

Question 16

what is attitiudeUpdated ?

Answer 16

the signal being sent to the target.. it is not the name of the send signal action

Question 17

if a signal has been updated , Cameo updates the send signal action input ____ on the send signal action

Answer 17

Pins

Question 18

what is authenticationResponseSent ?

The ______ that has been assigned to a send signal action

Answer 18

signal

Question 19

what does this accept event action require to start executing ?

Answer 19

when a control token is received

Question 20

What type of action do you use when you want to wait for an event to occur before allowing execution to proceed ?

Answer 20

accept event actions

Question 21

why not call it an accept signal action instead of accept event action ?

Answer 21

accept event action can wait for any of these events not just signals
1. signal event
2. call event
3. change event
4. time event

Question 22

in the language there are 4 kinds of events defined to model an event occurrence that may trigger an execution of a behavior

1. signal event
2. call event
3. change event
   4.

a event occurs at some discrete moment in time it has no duration

Answer 22

time event

Question 23

a event occurs at some discrete moment in time it has no ________
a behavior occurs at some moment in time it may trigger an execution of a behavior

Answer 23

duration

Question 24

what is an event pool ?

Answer 24

an event pool - abstract concept its not a model element thats baked in to the rules of the language on how

picture a **bucket **where event occurrences get buffered until a behavior consumes it

each instance of an object owns its own event pool

Question 25

When does the activity look at the owning object event pool to see if that specified event has or has not yet occured ? only when an __________action is executed

Answer 25

accept event each instance owns its private event pool each instance could be executing multiple behaviors each behavior does not have their own event pool

Question 26

when an a control token arrives the accept event action looks at the event pool for

Answer 26

a signal

Question 27

if two activities are competing with each other ( looks at the event pool for a signal ) is an example of a ______ condition

Answer 27

race condition

Question 28

the owning activity looks at the event pool only when a ______________ action is executing . Not when a basic action is executing or any other action is occurring

Answer 28

accept event action

Question 29

if two behaviors are waiting for the same signal in the event pool

Answer 29

its non deterministic . you cant tell which action will consume it

Question 30

Review a wait time action is waiting specifically for a **time event trigger**

Answer 30

an accept event controls the flow of execution waiting for a signal to arrive in an event pool.

Question 30

a wait time action is waiting specifically for a time event trigger not a signal not a call event not a change event

Answer 30

an accept event controls the flow of execution waiting for a signal to arrive in an event pool.

Question 31

two kinds of time event 1. **absolute** begins with the keyword **at** 2. **relative** time event begins with

Answer 31

the keyword **after**

Question 32

what kind of time event is this ?

Answer 32

absolute time event -- begins with at

Question 33

what kind of time event is this ?

Answer 33

relative time event -- begins with after

Question 34

what is this narritive

Answer 34

a continuous periodic behavior a wait time action with incoming edges when the activity begins every 2 mins the fire thruster behavior executes

Question 35

when is a accept event action continuously enabled

Answer 35

no incoming edges on an accept event it remains continuously enabled , it never terminates

Question 36

what kind of node is used to steer the execution of an activity along a path ?

Answer 36

control nodes ----- dashed lines control nodes can direct the path of control tokens as well as object tokens

Question 37

three ways an activity can terminate a token arrives at an activity final node all actions within the activity terminate another behavior can ______terminate the activity

Answer 37

externally

Question 38

if any token arrives at an **activity final node** all the actions

Answer 38

terminate

Question 39

special rule when an accept event action has no incoming action this action never _______ and it becomes continuously enabled

Answer 39

terminates

Question 40

7 kinds of control nodes 1. initial node 2. activity final node 3. flow final 4. decision node 5 merge node 6. fork node 7.

Answer 40

join node

Question 41

what two **controls nodes** are shown here ?

Answer 41

initial node fork node ( multiple edges going out of it )

Question 42

what do all control nodes have in common ? 1. all control nodes are used to define control logic 2. control nodes do not execute 3. the rules for all control nodes are expressed in terms of token ______

Answer 42

flows

Question 43

what does an initial node do ?

Answer 43

marks the start of control flow within the activity tokens traverse edges in zero time. the moment the activity begins

Question 44

when the owning activity begins executing a control token gets places on each initial _________

Answer 44

node. those tokens flow concurrently and independently

Question 45

is an initial node a requirement for an activity diagram ?

Answer 45

No

Question 46

ma does have an incoming edges or control flows , when does this action start executing ?

Answer 46

when the owning activity begins the action ma begins

Question 47

what does an activity final node represent ? termination of the execution of the action when any token ( object flow or control flow ) arrives it terminates an activity

Answer 47

an activity final node can have multiple edges coming into it , Can either be a control node or object node its not a requirement for an activity to have a final node .

Question 48

key ideas of a flow final node 1. marks the end of a single sequence of actions , not the entire activity 2. a flow final node can have a control flow or object flow arriving into it. 3. when 1 token arrives it ends the sequence of the action not the activity itself 4. flow final nodes are not required in the diagram

Answer 48

4. multiple edges can come in into flow final node

Question 49

key idea of decision node 1. a decision node represents an a OR statement . 2. when any token arrives at a decision node , all guard expressions are evaluated . if 1 guard is true then the token is passed on that edge how about if multiple guards are true ?

Answer 49

it becomes non-deterministic , the reader cant know which path the tokens takes

Question 50

key idea of a fork node when a token arrives at a fork node those tokens are duplicated and tokens . tokens flow concurrently and

Answer 50

independently if control flow comes in , control flow comes out if object flow comes in , object flow comes out

Question 51

join node all three of these actions must come to a stop before the action is

Answer 51

is done executing join node serves as a synchronization point

Question 52

scenarios for Join node only control flows come in and only a **single** control token flows out only object flows come in and ** all ** object nodes flow out if a control and object nodes are in a join node ... all the object tokens must arrive and no control tokens are

Answer 52

passed

Question 53

Activity partition displays who does what . An activity partition conveys _______

Answer 53

allocation totally optionally to add this in your diagrams

Question 53

the column flight computer is a an element that you have assigned to that activity

Answer 53

partition .

Question 54

four common elements to add that are structural representations in an activity partition 1. part property 2. block 3. actor 4.

Answer 54

reference property

Question 55

greatest weakness of activity partitions ?

Answer 55

cannot determine which element invokes an action