Mapped file base address is not honored

[bovine]

Karl reports that the base address specified for the memory mapped file may not be actually honored and that a self-assigned address is used instead.

[gahr]

I haven't looked at the code, but the MAP_FIXED flag to mmap comes to mind. Is that used already?

[resuna]

I had that in the original code.

if(addr == (char *)-1)
    addr = 0;
if(addr) flags |= MAP_FIXED;
map = mmap(addr, size, PROT_READ|PROT_WRITE, flags, fd, (off_t) 0);

It now looks like it's calling a BOOST API that may not provide as much control:

include <boost/interprocess/managed_mapped_file.hpp>

...

if (create != 0) { mmf = new managed_mapped_file(open_or_create, file, defaultsize, (void)addr); } else { mmf = new managed_mapped_file(openonly, file, (void)addr); } Need to check what Boost is doing.

On Wed, Jan 7, 2015 at 2:24 AM, Pietro Cerutti notifications@github.com wrote:

I haven't looked at the code, but the MAP_FIXED flag to mmap comes to mind. Is that used already?

— Reply to this email directly or view it on GitHub https://github.com/flightaware/speedtables/issues/46#issuecomment-68991505 .

[resuna]

This might be worked on alongside the fix to issue #38 if boost allows for it.