Section 4: Synchronization, Data Generation and Data transfer

Question 1

What is the producer/consumer model

Answer 1

Producer: software or hardware responsible for producing data or events for the consumer
Consumer: software or hardware that consumes data or events from producer

Question 2

What is data

Answer 2

the information transferred between producers and consumers

Question 3

What is an Event

Answer 3

The control information transferred to represent that some event has occured

Question 4

What are the three levels of data synchronization?

Answer 4

Data Generation (when/why is data generated)
Data Notification (when/how do we inform the other party that we want to synchronize)
Data transfer (how do we send data between the two systems)

Question 5

Which of the data synchronization levels is mandatory

Answer 5

Data Transfer

Question 6

What is synchronization

Answer 6

The interaction required to allow interaction of two devices with different views of time

Question 7

What are the two types of synchronziation

Answer 7

Active: One system can force a change in the operation of the other (ie Interupts)
Passive Synchronization: One of the communicating entities requests service, however the receiving entity does not need to respond

Question 8

What are three types of data sources

Answer 8

Spontaneous: (data produced independent of consumer)
Consumer Sensitive: Data is produced only after prior data is consumed
Consumer Responsive: Data is produced when requested

Question 9

What is a consumer initiated notification scenario? What are some examples?

Answer 9

Consumer requests data from the consumer. Once data is available request is completed. Examples (polling for a key to be pressed, interrupt from a printer)

Question 10

What is a producer initiated notification scenario? What are some examples?

Answer 10

In producer initiated notification, the producer informs the consumer when data is available. Examples:
Polling for printer to be ready for next page, Sending an interrupt to be handled

Question 11

What is Data transfer

Answer 11

The exchange of info between two entities.

Question 12

What are three concerns with data transfer

Answer 12

Persistence: How long is data valid?
Tim syncrho: How signals are enabled to make transfer happen
Control Signals: How control info is exchanged

Question 13

What is persistent Data

Answer 13

data is valid until consumer signals data has been read

Question 14

What is transient data

Answer 14

data is valid for a finite amount of time. (most data)