| marp | author | theme | class |
|---|---|---|---|
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Rasmus Lystrøm |
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Rasmus Lystrøm Associate Professor ITU
Introduction
A property of systems in which several computations are executing simultaneously, and potentially interacting with each other. The computations may be executing on multiple cores in the same chip, preemptively time-shared threads on the same processor, or executed on physically separated processors.
Multiple tasks which start, run, and complete in overlapping time periods, in no specific order.
When multiple tasks OR several parts of a unique task literally run at the same time, e.g., on a multi-core processor.
Software implementation which allows different threads to be executed concurrently. A multithreaded program appears to be doing several things at the same time even when it's running on a single-core machine. Compare to chatting with different people through various IM windows; although you're switching back and forth, the net result is that you're having multiple conversations at the same time.
Asynchrony is used to present the impression of concurrent or parallel tasking. Normally used for a process that needs to do work away from the current application where we don't want to wait and block our application awaiting the response.
Behavior of a program where the output is dependent on the sequence or timing of other uncontrollable events. --> Bug, when events do not happen in the order the programmer intended.
A situation in which two or more competing actions are each waiting for the other to finish, and thus neither ever does.
Task.Run Task.Factory… Task.Delay Parallel.For Parallel.ForEach Parallel.Invoke
Parallel Linq --> .AsParallel()
ConcurrentQueue<T>
ConcurrentStack<T>
BlockingCollection<T>
ConcurrentDictionary<TKey, TValue>
Asynchronous programming is a means of parallel programming in which a unit of work runs separately from the main application thread and notifies the calling thread of its completion, failure or progress.
async -->
Method must return void, Task, Task<T>, ValueTask, ValueTask<T>, or a task-like type.
Specifically: a type, which satisfy the async pattern, meaning a GetAwaiter method must be accessible.
await --> Await task(s)...
Note: Asynchronous Main and test methods must return Task
Async: Non-blocking UI, background tasks, asynchronous
Parallel: Speed, Multiprocessor, Parallel execution
Thread: Low-level building block. Do not use directly!