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how to get mmap page size?
- From: Jay Foad <jay dot foad at gmail dot com>
- To: cygwin at cygwin dot com
- Date: Fri, 16 Jan 2009 12:24:16 +0000
- Subject: how to get mmap page size?
I have an application that wants to use mmap() to read a file, but
only if it can guarantee that this will leave one or more zero bytes
after the end of the contents of the file in memory:
if ((filesize & (pagesize - 1) != 0)
use_mmap();
else
use_read();
How do I get the appropriate page size on cygwin?
If I call getpagesize() it returns 64k, the "allocation granularity".
Internally cygwin has a getsystempagesize() (introduced here:
http://cygwin.com/ml/cygwin-cvs/2005-q4/msg00099.html) that returns
the appropriate page size, 4k, but that doesn't seem to be exposed to
applications.
I know that this has been discussed before, e.g. here:
http://www.cygwin.com/ml/cygwin/2002-01/msg00747.html
but I haven't found an answer to this particular question.
Thanks,
Jay.
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