We don't have access to an appropriate context to create the dead wrapper in
when the callback is nuked, so instead, this patch creates a new dead wrapper
in the caller compartment each time the property is accessed. This is the same
behavior we'd get when trying to re-wrap a cross-compartment dead wrapper, so
it's consistent with the way we handle these situations elsewhere.
MozReview-Commit-ID: 3cMeR4z8EOe
--HG--
extra : rebase_source : 7e8cf4a195ef64deb7677ce4ac9818d342815667
Currently we resolve a property by iterating every prefable and check whether it
is enabled. If it is, we linear search the ids that it manages. This patch
changes that to binary searching to find whether the id being resolved is
present first, and checking whether its prefable is enabled only when we find
it. This improves the performance of property resolution, especially when the
property is not present.
The patch stores all the property ids a NativePropertiesN owns in a single array
of PropertyInfo structs. Each struct contains an id and the information needed
to find the corresponding Prefable for the enabled check, as well as the
information needed to find the correct property descriptor in the Prefable. We
also store an array of indices into the PropertyInfo array, sorted by bits of
the corresponding jsid. Given a jsid, this allows us to binary search for the
index of the corresponding PropertyInfo, if any. The index array requires 2
bytes for each property, which is ~20k across all our bindings. The extra
information stored in each PropertyInfo requires 4 bytes for each property,
which is about 40k across all our bindings in 32-bit builds, or 80k in 64-bit
builds due to alignment requirements on PropertyInfo. However we save a bit of
memory from changing NativePropertiesN's trios to duos.
The array of unsorted ids is kept because XrayOwnPropertyKeys() includes only
properties that are enabled. Without it, we will need to check every single
property to know whether its prefable is enabled or not, which is inefficient.
With this patch, initializing property ids takes longer because of the sorting.
I measured also insertion sort because I thought the ids should be nearly sorted
as they are generated sequentially at run time, but that's not the case and
NS_QuickSort() runs faster.
MozReview-Commit-ID: Lc4Z1ui3t0o
--HG--
extra : rebase_source : 314efe467a14428c57f90af2ecc0ec5c47a31993
The patch makes the following proxy changes:
* The number of slots in ProxyValueArray is now dynamic and depends on the number of reserved slots we get from the Class.
* "Extra slots" was renamed to "Reserved slots" to make this clearer.
* All proxy Classes now have 2 reserved slots, but it should be easy to change that for proxy Classes that need more than 2 slots.
* Proxies now store a pointer to these slots and this means GetReservedSlot and SetReservedSlot can be used on proxies as well. We no longer need GetReservedOrProxyPrivateSlot and SetReservedOrProxyPrivateSlot.
And some changes to make DOM Proxies work with this:
* We now store the C++ object in the first reserved slot (DOM_OBJECT_SLOT) instead of in the proxy's private slot. This is pretty nice because it matches what we do for non-proxy DOM objects.
* We now store the expando in the proxy's private slot so I removed GetDOMProxyExpandoSlot and changed the IC code to get the expando from the private slot instead.
Specifically, three changes:
1) valueOf should be non-enumerable.
2) valueOf should be === to Object.prototype.valueOf.
3) There should be no toJSON.
The tests come directly from https://github.com/w3c/web-platform-tests/pull/4623
so not much need to review them.
Kris Maglione
Boris Zbarsky
Jon Coppeard
Nicolas Silva
Benjamin Bouvier
Edgar Chen
Ting-Yu Chou
Jan de Mooij
John Dai
Ben Kelly
Andrea Marchesini
Brian Hackett
Sebastian Hengst
Tomislav Jurin
Peter Van der Beken
Jeff Walden
Tooru Fujisawa