Win32: shared memory base addresses and remapping. Two mechanisms are implemented to make it possible to store pointers in shared memory on Windows, in particular on Windows Vista and later versions with ASLR: - The ngx_shm_remap() function added to allow remapping of a shared memory zone to the address originally used for it in the master process. While important, it doesn't solve the problem by itself as in many cases it's not possible to use the address because of conflicts with other allocations. - We now create mappings at the same address in all processes by starting mappings at predefined addresses normally unused by newborn processes. These two mechanisms combined allow to use shared memory on Windows almost without problems, including reloads. Based on the patch by Sergey Brester: http://mailman.nginx.org/pipermail/nginx-devel/2015-April/006836.html

# Copyright (C) Igor Sysoev
# Copyright (C) Nginx, Inc.


echo $ngx_n "checking for uintptr_t ...$ngx_c"
echo >> $NGX_AUTOCONF_ERR
echo "checking for uintptr_t" >> $NGX_AUTOCONF_ERR

found=no

cat << END > $NGX_AUTOTEST.c

#include <sys/types.h>
$NGX_INTTYPES_H

int main() {
    uintptr_t i = 0;
    return (int) i;
}

END

ngx_test="$CC $CC_TEST_FLAGS $CC_AUX_FLAGS \
          -o $NGX_AUTOTEST $NGX_AUTOTEST.c $NGX_LD_OPT"

eval "$ngx_test >> $NGX_AUTOCONF_ERR 2>&1"

if [ -x $NGX_AUTOTEST ]; then
    echo " uintptr_t found"
    found=yes
else
    echo $ngx_n " uintptr_t not found" $ngx_c
fi

rm -rf $NGX_AUTOTEST*


if [ $found = no ]; then
    found="uint`expr 8 \* $ngx_ptr_size`_t"
    echo ", $found used"

    echo "typedef $found  uintptr_t;"                   >> $NGX_AUTO_CONFIG_H
    echo "typedef $found  intptr_t;" | sed -e 's/u//g'  >> $NGX_AUTO_CONFIG_H
fi