Re: Has "stack overflow" specified behavior?

From	"Alf P. Steinbach" <alf.p.steinbach@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: Has "stack overflow" specified behavior?
Date	2021-12-14 16:16 +0100
Organization	A noiseless patient Spider
Message-ID	<spach1$fia$1@dont-email.me> (permalink)
References	(2 earlier) <sp6mqk$uob$1@gioia.aioe.org> <j1oj05Fk7miU1@mid.individual.net> <dhHtJ.117237$np6.3909@fx46.iad> <sp9h9l$gbc$1@dont-email.me> <op0uJ.41655$aY3.33389@fx21.iad>

Show all headers | View raw

On 14 Dec 2021 13:49, Richard Damon wrote:
> 
> On 12/14/21 2:32 AM, Bonita Montero wrote:
>> Am 13.12.2021 um 13:47 schrieb Richard Damon:
>>
>>> Actually, most threading libraries creat threads with a FIXED sized 
>>> stack (specified in the create call or it uses a default), and that 
>>> space is all reserved for the thread stack.
>>
>> How would an implementation of a variable stack space look like when
>> the stack can't be moved because of pointers inside the stack-frames ?
>>
> 
> It doesn't.
> 
> The Thread APIs I know create a FIXED size stack for a new thread and it 
> can not be changed/moved after the thread is started.
> 
> The fact that there can exist pointers to data on the stack (possible on 
> the stack) is one big reason for this limitation.
> 
> Just like if you use realloc you need to be careful of dangling 
> references to the old buffer, trying to move a thread stack is a hard, 
> likely impossible, problem.
> 
> The main thread stack can be expandable, as it often has a special 
> relationship to the heap, so you can trade memory between the stack and 
> the heap. There is normally only one such special location.
> 
> I suppose you could grossly over-allocate the stack space for a thread 
> and then create some sort of auxiliary heap at the end of it, and trade 
> of use of that heap with stack space for that thread.

It's technically possible to use (that is, for the compiler to support) 
a linked list based stack, and that could be preferable for real coroutines.

AFAIK no compiler linked list stack by default, but apparently gcc 
supports, or at least did support when one used the "gold linker", a 
scheme called a "split stack".

I'm not sure but googling it now and looking at the first hit it seems 
that the compiler generates additional stack checking instructions that 
allocates and links up a new stack part when the current is too small. 
I.e. this is not a linked list of stack frames but a linked list of 
stack parts.

https://gcc.gnu.org/wiki/SplitStacks

---

With 64-bit addressing and a reasonably low number of threads I guess 
one could in principle just allocate a largish address range for each 
stack, and expand the backing in terms of real memory pages, as needed, 
perhaps with the need detected via a guard page to avoid overhead of 
stack size checking code in every function.

E.g. in Windows pages are managed via `VirtualAlloc` function & friends.

But I haven't heard of such scheme being used.

- Alf

Thread

Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-12 00:42 -0800
  Re: Has "stack overflow" specified behavior? Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-12 09:52 +0100
    Re: Has "stack overflow" specified behavior? red floyd <no.spam.here@its.invalid> - 2021-12-12 12:59 -0800
  Re: Has "stack overflow" specified behavior? Paavo Helde <eesnimi@osa.pri.ee> - 2021-12-13 01:51 +0200
    Re: Has "stack overflow" specified behavior? Juha Nieminen <nospam@thanks.invalid> - 2021-12-13 05:48 +0000
      Re: Has "stack overflow" specified behavior? Bo Persson <bo@bo-persson.se> - 2021-12-13 10:44 +0100
        Re: Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-13 04:44 -0800
        Re: Has "stack overflow" specified behavior? Richard Damon <Richard@Damon-Family.org> - 2021-12-13 07:47 -0500
          Re: Has "stack overflow" specified behavior? Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-14 08:32 +0100
            Re: Has "stack overflow" specified behavior? Richard Damon <Richard@Damon-Family.org> - 2021-12-14 07:49 -0500
              Re: Has "stack overflow" specified behavior? scott@slp53.sl.home (Scott Lurndal) - 2021-12-14 14:23 +0000
              Re: Has "stack overflow" specified behavior? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-12-14 16:16 +0100
        Re: Has "stack overflow" specified behavior? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-12-13 12:13 -0500
          Re: Has "stack overflow" specified behavior? Öö Tiib <ootiib@hot.ee> - 2021-12-13 12:05 -0800
            Re: Has "stack overflow" specified behavior? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-12-13 17:11 -0800
            Re: Has "stack overflow" specified behavior? "james...@alumni.caltech.edu" <jameskuyper@alumni.caltech.edu> - 2021-12-13 19:00 -0800
              Re: Has "stack overflow" specified behavior? Öö Tiib <ootiib@hot.ee> - 2021-12-13 23:03 -0800
          Re: Has "stack overflow" specified behavior? Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-14 08:33 +0100
            Re: Has "stack overflow" specified behavior? David Brown <david.brown@hesbynett.no> - 2021-12-14 09:13 +0100
              Re: Has "stack overflow" specified behavior? Juha Nieminen <nospam@thanks.invalid> - 2021-12-14 10:09 +0000
                Re: Has "stack overflow" specified behavior? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-14 16:14 +0000
                Re: Has "stack overflow" specified behavior? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-12-14 15:23 -0800
              Re: Has "stack overflow" specified behavior? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-14 16:10 +0000
              Re: Has "stack overflow" specified behavior? Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-14 17:38 +0100
                Re: Has "stack overflow" specified behavior? scott@slp53.sl.home (Scott Lurndal) - 2021-12-14 17:09 +0000
                Re: Has "stack overflow" specified behavior? Bonita Montero <Bonita.Montero@gmail.com> - 2021-12-14 18:39 +0100
                Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-14 11:01 -0800
              Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-14 10:52 -0800
                Re: Has "stack overflow" specified behavior? David Brown <david.brown@hesbynett.no> - 2021-12-14 20:15 +0100
            Re: Has "stack overflow" specified behavior? Richard Damon <Richard@Damon-Family.org> - 2021-12-14 07:59 -0500
          Re: Has "stack overflow" specified behavior? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-12-14 16:19 +0100
            Re: Has "stack overflow" specified behavior? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-12-14 11:33 -0500
      Re: Has "stack overflow" specified behavior? Manfred <noname@add.invalid> - 2021-12-13 17:23 +0100
      Re: Has "stack overflow" specified behavior? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2021-12-15 23:27 +0000
        Re: Has "stack overflow" specified behavior? David Brown <david.brown@hesbynett.no> - 2021-12-16 08:37 +0100
    Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-13 14:16 -0800
      Re: Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-13 15:07 -0800
        Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 05:53 -0800
          Re: Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-16 08:34 -0800
            Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-16 12:17 -0800
              Re: Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-16 13:38 -0800
                Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-16 14:15 -0800
            Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 20:10 -0800
          Re: Has "stack overflow" specified behavior? Öö Tiib <ootiib@hot.ee> - 2021-12-16 14:14 -0800
            Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 20:20 -0800
              Re: Has "stack overflow" specified behavior? Öö Tiib <ootiib@hot.ee> - 2021-12-17 08:46 -0800
      Re: Has "stack overflow" specified behavior? Paavo Helde <eesnimi@osa.pri.ee> - 2021-12-14 10:32 +0200
        Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 07:42 -0800
          Re: Has "stack overflow" specified behavior? Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2021-12-17 01:07 +0000
            Re: Has "stack overflow" specified behavior? Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-12-17 01:28 +0000
            Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-16 19:54 -0800
              Re: Has "stack overflow" specified behavior? Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2021-12-17 10:06 +0000
  Re: Has "stack overflow" specified behavior? Manfred <noname@add.invalid> - 2021-12-13 17:08 +0100
    Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-13 13:50 -0800
      Re: Has "stack overflow" specified behavior? Manfred <noname@add.invalid> - 2021-12-14 16:32 +0100
  Re: Has "stack overflow" specified behavior? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-12-13 13:13 -0800
  Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-13 15:55 -0800
    Re: Has "stack overflow" specified behavior? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-12-13 15:58 -0800
    Re: Has "stack overflow" specified behavior? wij <wyniijj@gmail.com> - 2021-12-14 01:41 -0800

csiph-web