id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
9019	Bug: mapped_region shouldn't create a new file mapping but reuse the one provided in file_mapping	michal.fronczyk@…	Ion Gaztañaga	"In the constructor of the mapped_region class there is the following code:

{{{
native_mapping_handle = winapi::create_file_mapping
            ( ipcdetail::file_handle_from_mapping_handle(mapping.get_mapping_handle())
            , protection, 0, 0, 0);
}}}

followed by the following:


{{{
void *base = winapi::map_view_of_file_ex
                                 (native_mapping_handle,
                                 map_access,
                                 offset - page_offset,
                                 static_cast<std::size_t>(page_offset + size),
                                 const_cast<void*>(address));
}}}

Each invocation of the mapped_region's class constructor creates a new mapping. I think the code that creates the file mapping should be moved to the file_mapping class, so multiple mapped_regions could reuse the same file mapping. Currently, even if the same file_mapping instance is passed to the mapped_region's constructor, the file mapping isn't reused which makes creating multiple mapped regions of the same file slow."	Bugs	closed	To Be Determined	interprocess	Boost 1.54.0	Optimization	fixed	interprocess mapped_region file_mapping