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

--- a/src/core/ngx_cycle.c
+++ b/src/core/ngx_cycle.c
@@ -863,6 +863,22 @@ ngx_init_zone_pool(ngx_cycle_t *cycle, n
             return NGX_OK;
         }
 
+#if (NGX_WIN32)
+
+        /* remap at the required address */
+
+        if (ngx_shm_remap(&zn->shm, sp->addr) != NGX_OK) {
+            return NGX_ERROR;
+        }
+
+        sp = (ngx_slab_pool_t *) zn->shm.addr;
+
+        if (sp == sp->addr) {
+            return NGX_OK;
+        }
+
+#endif
+
         ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
                       "shared zone \"%V\" has no equal addresses: %p vs %p",
                       &zn->shm.name, sp->addr, sp);