[cap-talk] Fetching dynamic libraries in Native Client

[Mark Seaborn]

I am working on implementing dynamic loading/linking support in Native
Client at the moment.  (This follows on from my work last year where I
prototyped dynamic loading support, but the code was not merged
upstream at the time.)  cap-talkers might be interested in some of the
related discussions on the native-client-discuss list [1].

The issues of how to fetch sets of libraries, and how interfaces for
fetching files relate to DOM APIs and same origin policies [2], are
related to past discussions about modules on e-lang [3] and to
discussions about CORS on cap-talk.  The issue of how to implement
basic dynamic loading of code in NaCl [4] is less related to
capabilities (except to the extent that NaCl has a code verifier and
so do obj-cap subset languages such as Joe-E).

One question is whether NaCl processes running under the web browser
should receive a NaCl-specific TCB-provided interface for fetching
URLs, or whether NaCl processes have to communicate with Javascript
objects which can fetch files on the process's behalf using
XMLHttpRequest or similar [5].  Some people want a NaCl-specific
interface so that a NaCl program can be self-sufficient (containing
references to all the libraries it needs) and embedded across origins
via an <embed> tag, pointing to a single URL, similar to the way Flash
apps can be embedded.

Mark

[1] http://groups.google.com/group/native-client-discuss
    There's an alternative archive at:
    http://news.gmane.org/gmane.comp.security.nativeclient.general
[2] http://code.google.com/p/nativeclient/wiki/AcquiringDynamicLibraries
[3] For example, the "Module naming and identification" thread:
    http://www.eros-os.org/pipermail/e-lang/2009-April/013081.html
[4] http://code.google.com/p/nativeclient/wiki/DynamicLoadingOptions
    http://code.google.com/p/nativeclient/wiki/DynamicLinkingPlan
[5] http://groups.google.com/group/native-client-discuss/browse_frm/thread/bb06957ae061b65a