On Wed, 6 Oct 2021 17:01:58 GMT, Ioi Lam <ik...@openjdk.org> wrote: >> see above reply. We need read the full _header_size for _header. Also note >> that helper class will delete gen_header when out of scope. > > I see. I think your current code is fine. > > Note that the current code writes the header as a FileMapHeader, but it reads > it as both a FileMapHeader and a CDSFileMapHeaderBase. So it has the basic > assumption `FileMapHeader::_generic_header` is at offset 0 of FileMapHeader. > Therefore, in FileHeaderHelper::initialize, we should add an assert: > > > static_assert(offsetof(FileMapHeader, _generic_header) == 0, "must be");
This caused compiling error: since FileHeaderHelper is not a friend of FileMapHeader so no access to its fields: error: 'GenericCDSFileMapHeader CDSFileMapHeaderBase::_generic_header' is inaccessible within this context ------------- PR: https://git.openjdk.java.net/jdk/pull/5768
