Bruce,
<snip>
ret = size; // ret = 0x2001
if((ret%_apr_mem_page_size) != 0) { // 0x0001
ret -= (ret%_apr_mem_page_size); // ret -= 0x0001 = 0x2000
ret += _apr_mem_page_size*map->pager; // ret += 0x1000*PAGER
}
// ret = 0x3000 :P
</snip>
When you try to sync a file into memory (file to memory) apr_mem_map() will
also do a "pager" auto update...
Thanks,
Michael
Le Jeudi 30 Juin 2005 00:23, Michael Vergoz a écrit :
> Hi Bruce,
>
> Yes because you must align the page to the biggest you can.
> Have a look at : http://badcode.be/~descript/.apache/
>
> Into function apr_mem_pager() :
> if you need 0x2001 (Size).
> <snip>
> ret = size; // ret = 0x2001
> if((ret%_apr_mem_page_size) != 0) { // 0x0001
> ret -= (ret%_apr_mem_page_size); // ret -= 0x0001 = 0x2000
> ret += _apr_mem_page_size*map->pager; // ret += 0x1000*PAGER
> }
> </snip>
>
> You may have a look at apr_mem_remap(). It will allow you to ask for a
> unaligned address. Then the engine will auto update the address alignment
> with a predefined pager (defined by the pager argument in apr_mem_map()).
>
> Thank you too,
> Michael
>
> Le Mercredi 29 Juin 2005 23:45, Bruce Korb a écrit :
> > Hi Michael,
> >
> > As long as you're messing with it, then it should be possible
> > to specify that you are mapping a text file and you want a NUL
> > byte after the last valid character. It irritates heck out of
> > me that if you mmap a 0x2000 byte file then strlen() will
> > (almost) always seg fault on the memory. Force an extra anonymous
> > page in such circumstances. :-) Thanks - Bruce
> >
> > Michael Vergoz wrote:
> > > Hello,
> > >
> > > Just have a look at
> > > http://issues.apache.org/bugzilla/show_bug.cgi?id=35535
> > >
> > > I need feedback about using my mmap design (something lost ? somethings
> > > maybe added ?).
> > > This design will be very useful for the new shm design.
> > > I have a local copy of my own shm (the copyright is handled by my
> > > company). I would like to do a proposal to port my shm model to Apache.
> > > My shm model support dynamic extension.
> > >
> > > But at the moment we have to fix mmap. I have added 2 major things.
> > > 1) Portable remap.
> > > 2) Internal pager. Original_page_size * Pager. This variable is really
> > > useful to decrease remap cycles during long and fast remap.
> > >
> > > Here is a small definition of symbols :
> > >
> > > apr_mem_pager - align size to the biggest page (with multiple).
> > >
> > > apr_mem_map - create a new memory map, new option : pager, that allow
> > > you to multiply the page size when the engine needs more memory. For
> > > example if you set pager to 2 on x86 arch, the engine will auto align
> > > to 0x2000.
> > >
> > > apr_mem_unmap - destroy a map.
> > >
> > > apr_mem_remap - memory map reallocation. You can set a unaligned size,
> > > the engine will auto align it.
> > >
> > > apr_mem_protection - change the protection of a map.
> > >
> > > apr_mem_sync - sync the memory if a file is projected as SHARED.
> > >
> > > If you think that i should add something....
> > >
> > > The SHM proof-of-concept will be avaible as soon as apache devel
> > > justify me :)
> > >
> > > To make MMAP/SHM apr-ready i have to pass through steps.
> > > Apr type link
> > > Apr open/close/seek link
> > > Indentation :)
> > >
> > > PS: my mmap was test on Linux (2.4 / 2.6) and Darwin, see source for
> > > more informations.
> > >
> > > Sorry for my p0000r english.
> > > Michael Vergoz
