The JSWindowActor constructor is called before the actor is fully initialized,
which means it can't do things like send messages or access its content
window. This patch adds a new callback which can do those things immediately
after the actor is created.
Differential Revision: https://phabricator.services.mozilla.com/D42178
--HG--
extra : rebase_source : ba17cacb00d8fc74f84c5d34f64addcc3e6d3f8b
extra : source : ac3da20c687971c412d1164f08b17e0cccc5fbd5
There are a couple of places where JSWindowActor currently sends uninitialized
StructuredCloneData objects in places where it wants the message data to be
undefined. The problem with this is that it causes an error when trying to
read the data, which leads to odd behavior like `sendQuery` promises never
being settled if the message handler throws, or `sendAsyncMessage` and
`sendQuery` failing to decode the message if the caller doesn't pass a second
argument.
The errors reported for these problems also have no context, which means it's
very hard for a developer to figure out the source of the problem. And, to
make matters worse, the errors look the same as structured clone encoding
errors, so there isn't even the clue that the error is happening on decode.
This patch updates the offending code to always explicitly initialize the
structured clone data with `undefined` when that's what it wants, and adds
assertions to make it more obvious where the decode errors are actually
happening.
Differential Revision: https://phabricator.services.mozilla.com/D35052
--HG--
extra : rebase_source : dd4720d63cd0722a554524e65d16e31b702adbf3
extra : source : 158a4000c44b9b17a7935340db79431d544fb556
The current JSWindowActor code assumes that all actors will be created in the
shared JSM global. This has a few problems:
1) For actors in other scopes, it enters the wrong compartment before decoding
messages, which leads to a compartment checker error when trying to call
message handlers. That could be fixed by just wrapping the result for the
caller, but that would lead to other problems. Aside from the efficiency
concerns of having to deal with cross-compartment wrappers, SpecialPowers in
particular would not be able to pass the resulting objects to unprivileged
scopes, since only SpecialPowers compartments have permissive CCWs enabled.
2) It also leads to the prototype objects for the actor instances being
created in the shared JSM scope, even when the actors themselves are defined
in other compartments. Again, aside from CCW efficiency issues, this prevents
the SpecialPowers instances from being accessed by the unprivileged scopes
that they're exposed to, since the prototype objects live in privileged scopes
which don't have permissive CCWs enabled.
This patch changes child actors to always create their objects in the global
of their constructors.
The parent objects are still created in the shared JSM global, but they now
wrap values for the appropriate compartment before trying to call message
handlers.
Differential Revision: https://phabricator.services.mozilla.com/D35051
--HG--
extra : rebase_source : 436ce516080812680d1433bf3ecbd12f91d88165
extra : source : 61fa2745733f3631488a3ecccc144823683b7b6d
This adds a single new method, which acts like sendAsyncMessage, but
also returns a promise. This promise is fulfilled when the promise
returned from the receiveMessage callback is resolved.
```
partial interface JSWindowActor {
[Throws]
Promise<any> sendQuery(DOMString messageName,
optional any obj,
optional any transfers);
}
```
Differential Revision: https://phabricator.services.mozilla.com/D27809
--HG--
extra : moz-landing-system : lando
Agi Sferro
John Dai
Kris Maglione
Olli Pettay
Csoregi Natalia
Nika Layzell