Hi Bob,

this has nothing to do with resmgr issues. You are trying to modify the 
contents of a constant string literal. Bad, Bad, boy! 

In your code, you declare a pointer to char and initialize it to point 
to a constant string:
 17  char *buffer = "Hello world\n";
  ...

That's ok. Well - not really. IMHO, if you tried compiling with all
warnings 
on, the compiler should tell you 'warning: initialization discards
qualifiers 
from pointer target type', because the literal on the right is constant,
while 
the target of your pointer is not. The strange thing is: The compiler
doesn't
warn. Any compiler gurus around? Is this a bug or a feature?

Anyway, with the string literal being implicitly treated as 'constant',
it 
ends up in the ".rodata" (read-only-data) section of your executable and

resides in a memory portion that is mapped read-only, i.e., any
attempted 
write-access will cause a memory fault, thus enforcing the constantness
of 
your constant strings.

To avoid this, you could e.g. replace the  '*buffer=""' by
   char buffer[] = "Hello world\n";

That way, you'd get an initialized array (just large enough for the
initial 
string) that will actually be writable.

- Thomas 

> -----Ursprungliche Nachricht-----
> Von: bob lipka [mailto:bobik@os.pl]
> Gesendet: 14 July 2008 12:19
> An: ostech-core_os
> Betreff: Memory fault in resource manager
> 
> 
> In multithreaded resource manager example from neutrino 
> programmers guide I try to write to global char  string from 
> io_read function. This produces memory fault. How can I have  
> not only read, bul also write access to global variables in 
> io_xxx procedures attached in res mgr?
> 
> Souce attached. This is only an example to illustrate my 
> problem, I am not just curious about writing 'X' to some char 
> string :)
> 
> RobertL
> 
> _______________________________________________
> OSTech
> http://community.qnx.com/sf/go/post10447
>