Lesson Objectives Aims You should be able to: Identify points in a solution where a decision must be made Determine logical conditions that affect the outcome of a decision Determine how decisions affect flow through a program Determine parts of a problem that can be tackled at the same time Outline the benefits and trade offs that might result from concurrent processing in a solution

Note Before we start: You should’ve realised before now that this entire section is based on concepts that will make you a better programmer There is no easy way to learn these techniques and “thinking logically” and the like will only come with practise Some of these specification objectives are only possible to learn when you are coding a solution and solving the unique problems that arise There is an expectation in 6th form that you care about the subjects you take and are motivated, without us telling you, to study outside of school Studying programming shouldn’t be seen as a hassle, it should be something that you’re interested in, motivated to do and want to learn by yourself If you are not programming now, you are already falling behind.

This whole course is about thinking logically It is the process of being able to: Identify a problem Break it down (decomposition) Removing unnecessary complications and focussing on the true problem (abstraction) Identifying concurrency, algorithms, efficiency savings etc Designing the solution

Logic Thinking logically mainly focusses on the ability to solve a given problem You are only using a small set of rules or syntax to enable you to do this What are the steps that must be taken? In what order? What is the eventual goal? What decisions must be made?

Problem The problem with “teaching” logical thought is that…. You either can or can’t! You will only get better through practise and by solving problems by creating code And inevitably debugging that code So the coding challenges are incredibly important

Concurrency Concurrency is the idea of doing multiple things at the same time Some problems are very sequential in their nature- things must happen in order and each step relies on the previous Some are much more parallel: Whilst the kettle is boiling… Go and get a cup and put a tea bag in it Get the milk and pour in to the cup

This is made possible in modern machines through multi core processors Concurrency This is made possible in modern machines through multi core processors But concurrency does not only apply to computers – we can use it to: Model projects Suggest time savings in existing processes Manage human resources

Benefits and Trade-offs of Concurrency Faster processing More things can happen during the same time window Energy efficiencies As more is being done each cycle, we use less energy Efficient use of resources Less idle processor time, more time available for other tasks Less apparent lag when running a program

Not suitable for all tasks Increased complexity Programs must be specifically designed to work concurrently (threading) Compilers need to be able to explicitly target multi-core architectures Not suitable for all tasks It is not possible to make all problems concurrent Does not provide a doubling of speed Some tasks may be more/less concurrent than others Some threads may have to wait for the outcome of others to proceed

Practice paper – 1b A flight simulator is being developed to help train pilots…