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Thinking concurrently

1. A house may have a burglar alarm system which continually monitors the front door, back door, windows, room upstairs, and downstairs.

   Is this parallel or concurrent processing?

   • It is concurrent processing.

Exercises

1. ​
   1. Distinguish between parallel processing and concurrent processing.
      • Both parallel and concurrent processing handle many tasks at once.
      • Parallel processing runs its tasks simultaneously, whereas concurrent shares the processing time between tasks without actually executing them simultaneously.
   2. A school runs a local area network linking computers throughout the school. Describe how concurrent processing can be achieved on the network.
      • Concurrent processing can be achieved by allocating processing time to each machine in turn (although with many parallel machines, parallel processing would most likely be easier)
   3. When a class of students all try and download a piece of software at the beginning of a class, performance is affected. Explain why.
      • The bandwidth on the local area network is too low, so most machines wait while other machines download, and these execute concurrently - only one computer can be downloading data at any one time