Re: Stack vs. Heap Question, Please Help

Nick Hounsome <nh002@xxxxxxxxxxxxxxxxxx> wrote:
I don't know - I think that the idea of variables being on the stack or
on the heap (along with the concept of stack frames) is very important
when it comes to understanding threading, and why if two threads are
running the same method at the same time (or even a single thread
running a method recursively) they get separate local variables, but if
they access the same object on the heap, that data is shared.

struct parameters and structs within methods are thread local as
(recursively) are any structs they contain directly. Everything else is
shared. You don't need to use the words stack or heap to explain this.

You don't *need* to, but it helps IMO.

(Things get a lot more complicated with anonymous methods, by the way -
variables which look local can end up being captured, and then at
different levels. All kinds of weird stuff can happen.)

P.S. It is totally possible to implement a stack in a stackless
architecture - just pass a pointer to the array of arguments and allocate
frames off the heap - of course you then have a "stack" but it is a
different sort of stack and not as efficient for aloocation although the
deallocation efficiency still applies.

Sure.

--
Jon Skeet - <skeet@xxxxxxxxx>
http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
If replying to the group, please do not mail me too
.

Relevant Pages

  • Re: Memory (Structure vs Class)
    ... Such a block of memory which is ... actually so can structs ... heap while structures would be the stack unless declared global. ...
    (microsoft.public.vb.general.discussion)
  • Re: How does managed code work?
    ... Does it work the same way as the native stack with a frame pointer that is the head of a linked list of stack frames where each time we enter a function we create a new stack frame in which new variables are pushed and each time we exit a function the entire stack frame is popped? ... Can someone point me to a discussion of the managed heap? ... How does it prevent memory leaks that occur in COM when two objects reference each other and keep the others reference count nonzero? ... Because objects don't go out of scope, ...
    (microsoft.public.dotnet.languages.csharp)
  • Re: Groovy (war Re: [PROST]Re: CDC Plugin fuer Eclipse)
    ... Warum müsste man continuations erlauben Stackvariablen in den Heap zu verschieben? ... Ein activation record speichert die Parameter und lokalen Variablen der Funktion und eine Information, ... Da diese activation records klassischerweise auf einem Stack verwaltet werden, kann man hier Stackspace sparen - Endrekursion ist damit genauso effizient wie eine klassische Iteration mit einem Sprung. ...
    (de.comp.lang.java)
  • Re: Please Explain where will the struct be stored if it is declared inside the Class
    ... forget about structs for a second. ... can be stored either on the stack, or on the heap. ... First, think about the stack. ... A struct would act exactly the same as any of these decimals and ints. ...
    (microsoft.public.dotnet.languages.csharp)
  • Re: Is MSDN wrong? or I made a mistake? about static member function
    ... the heap" or some such reference. ... shouldn't we have a uniform notation? ... You can tell a heap object from a stack object by ... the result of trying to build a compiler on a tiny computer by someone who wasn't a very ...
    (microsoft.public.vc.mfc)