memory allocation of value types and reference types in .net framework

Is there an advanced article which I can read that can explain how memory is allocated for different types (value and reference) in .net framework.

for example we know that value types are allocated space on a stack, but how is that managed?

Also how are reference types managed in a heap and where are the actual values stored. (Reference type like any Class will contain many value types, where are they saved and how are they managed)

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It's more complicated than you might think. Even your claim that "value types are allocated on the stack" isn't correct. For example:

class Foo
{
    int x;
}

int is a value type, but the value for x will always be on the heap because it will be stored with the rest of the data for the instance of Foo which is a class.

Additionally, captured variables for anonymous functions and iterator blocks make life trickier.

I have an article about C# heap/stack memory you may find useful, but you might also want to read Eric Lippert's blog post on "The stack is an implementation detail". In particular, a future C# compiler could decide to store all of its local variables on the heap, using the stack just to hold a reference to an instance created at the start of the method... that wouldn't defy the C# spec at all.

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A value type is "allocated" where it is defined.

What that means depends on where you define it:

In a class/struct, as a field in that struct, enlarging the class/struct in memory to fit the value type value in there

As a local variable in a method, on the stack, or as a register, or as a field in a generated class (when using "closures"), depending on optimizations

As a parameter to a method, on the stack or as a register, depending on optimizations

A reference type is sort of a dual value. A reference type is at heart a pointer, and the pointer value follows the same rules for "allocation" as a value type, but once you store a value in it, ie. a reference to an object, that object is on the heap somewhere else.

In other words, the reference variable itself is "allocated" as a value type, but the object it refers to is on the heap.

When you construct an object from a class, space is allocated on the heap to fit all the fields of that class + some overhead in that space.

I seem to recall Jon Skeet having an article about the subject, I'm sure he'll jump in with an answer really soon so stay tuned.

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This article seems advanced without going overboard. It should provide you with a much better understanding:

http://www.simple-talk.com/dotnet/.net-framework/understanding-garbage-collection-in-.net/

链接地址: http://www.djcxy.com/p/80216.html

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