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.NET Synchronisation APIs - Part 1 - In-Process Synchronisation

Introduction This is the first in a series of posts on .NET synchronisation. I will cover: In-process synchronisation (this post) Out-of-process synchronisation on the same machine Distributed synchronisation In .NET, in-process synchronisation mechanisms are used to restrict access to shared resources and manage concurrency in multi-threaded applications. The mechanisms I'm going to present on this post can be used only for in-proc code, for synchronising threads, meaning, they cannot be used to synchronise multiple processes, on the same or on different machines - I will write more posts on these subjects and link them here. Here I will be using the terms "locking" and "synchronising on" interchangeably, to mean the same thing. I won't go into too much theory, but thread synchronisation exists for preventing: Race conditions: two threads trying to modify the same data simultaneously Data corruption: data shared by two or more threads becomes inconsistent ...
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EF Core State Validation

Introduction How many times have you tried to save changes to your context only to get an exception about validation problems, like a required property being null ? I certainly have, and because of this, I came up with a solution to figure out what is happening. I will also provide some possible solutions for the problem of fully validating an entity using the Data Annotations API  (a post on general validation with Data Annotations here ). State Validation All the entities that are currently tracked by a DbContext have some state known to the context. This state includes: The entity's state ( State ) in regards to persistence ( Modified , Added , Deleted , Unchanged ) Each property's values ( Property ), both current ( Current ) and original ( Original ) The entity itself ( Entity ) Any navigation properties ( References , Navigations ) So, we can iterate through each tracked entry by means of the Entries , Entries<T> , or Entry methods: var entity = ...; var ent...
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Location: Coimbra, Portugal
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Modern Mapping with EF Core

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Introduction In EF Core (as in most O/RMs) we can map and store multiple things: Objects that hold a single value, like int , string , bool , float , Guid , DateTime , TimeSpan , Uri , etc. These are (somewhat wrongly) called primitive types  and are always included inside some container, like the following Objects that hold multiple single values and which have an identity, for example, Customer , Product , Order . These are called entity types  and they must have an identity that makes them unique amongst all the other objects of the same type Objects that are structured to hold multiple values, but have no identity, such as Address , Coordinate . These are called value types  and are merely a collection of (possibly related) properties We can also have collections of the previous things There's more to it, of course, for example, it is even possible to represent  inheritance of entities , of which I talked about before , In this post I am going to cover so...
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Location: Coimbra, Portugal
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