[lug] Linux threads programming

[rm at fabula.de]

On Mon, Jan 13, 2003 at 01:32:56PM +0100, Carlos Hernandez wrote:
> Hi all,
> 
> We hope someone can give us a hint or redirect us to the right place.
> 
> We want to be able to rollback the state of a single thread in a
> multithread program under Linux (Debian Woody 2.4.20)
> 
> What we're doing  is : create a process with a few threads (each thread
> has a stack size of 10K),  periodically save the stack of one of them in
> a file. Eventually,  that thread exits, then we create another one  and
> try to recover the state saved in the file.

Just for my understanding: are you trying to implement some
sort of thread-local dump/undump by saving the C-callstack?
Hmm, if so, how do you intend to deal with absolute addresses stored
on the stack? If your stack holds addresses from _within_ the stack
(like local pointers that get passed down in function calls) these
pointers will be dangling after undumping.

 Ralf Mattes

> We're using sigsetjmp and siglongjmp functions. We are able to save the
> stack of the thread, but when we try to recover, the program aborts.
> Obviusly we're touching in prohibited place.
> 
> The example is attached in case someone want to have a look.
> 
> Any hints or comments are appreciate.
> 
> Thanks a lot.
> 
> Carlos
> 
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>