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Re: I'm new in cygwin: how to mmap?


Hi!

"Dr. Volker Zell" <Dr.Volker.Zell@oracle.com> wrote:

>>>>>> "Corinna" == Corinna Vinschen <vinschen@cygnus.com> writes:

>>     Corinna> Try using mmap().
> 
> Just curious. Whenever a configure script tries to detect a working mmap I get:
> 
>   checking for working mmap... no
> 
> Is this the expected behaviour. I'm using latest 1.1.4

cygwin  mmap  doesn't "work" as unix-world expects it should. on unix,
if  you  want  to  mmap  with  MAP_FIXED flag, you must supply address
aligned  to the page boundary, i.e. address should be x*pagesize. page
size on  windows  is  4096  and  test  program, which configure script
runs,   aligns    address    according  to  it. windows, otoh, require
that address should  be  aligned  to  "allocation  granularity"  which
is   64k.  if supplied  address  doesn't  match  this, and probability
that  it  won't  match   is   15/16, then windows fails to maf on this
address  with  error  1132   --   "The base address or the file offset
specified does not have the proper alignment."

Egor.            mailto:deo@logos-m.ru ICQ 5165414 FidoNet 2:5020/496.19



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