Fixes flakiness in worker tests that create a Worker or SharedWorker
with a missing script URL and only attach an error handler to it.
Once the test callback returns, nothing keeps the worker rooted from
JavaScript. If GC ran before the WebWorker process reported the
script fetch failure, the Worker/WorkerAgentParent cycle could be
collected and the error event never delivered, leaving the test hung
until timeout.
Hold startup-pending WorkerAgentParents from the outside
EnvironmentSettingsObject and release that edge once the script load
succeeds, fails, or the worker closes. The worker now survives long
enough to deliver its first script-load result.
Fixes the included imported test. Note that this required a minor
edit of the WPT import to work with our test harness setup to
try and create a non secure context setup as both file:// and
localhost are considered secure contexts.
Instead of passing through window's associated document's URL as
an extra argument to starting up a worker. This will allow for
improving the representation of 'outside settings' when setting
up a Worker.
The fetch requests for web worker scripts should be treated as if they
occurred in the caller global scope (which may be a Window) and not the
new worker's global scope. The referrer-policy/4K WPT subtests,
specifically those that test worker subresources, depend on this
behavior to work correctly. This commit fixes many of these subtests,
albeit via a hack where the serialized ESO's creation url is set to
the caller's document URL.
In the next commit, we will rely on global scope's URL being
initialized even earlier in the process of setting up the environment
for the Worker global. Move this hack just before that.
This is largely editorial. One behaviour change is that events are now
sent from a global task on the DOMManipulation task source.
Somewhat awkwardly, the spec refers to `this` before the Worker exists.
As it's for getting the relevant global object / settings object, I've
had to work around that.
Corresponds to:
917c2f6a73
Our structured serialization implementation had its own bespoke encoder
and decoder to serialize JS values. It also used a u32 buffer under the
hood, which made using its structures a bit awkward. We had previously
worked around its data structures in transferable streams, which nested
transfers of MessagePort instances. We basically had to add hooks into
the MessagePort to route to the correct transfer receiving steps, and
we could not invoke the correct AOs directly as the spec dictates.
We now use IPC mechanics to encode and decode data. This works because,
although we are encoding JS values, we are only ultimately encoding
primitive and basic AK types. The resulting data structures actually
enforce that we implement transferable streams exactly as the spec is
worded (I had planned to do that in a separate commit, but the fallout
of this patch actually required that change).
This change implements following behavior defined in the spec:
https://html.spec.whatwg.org/multipage/web-messaging.html#examples-5
> The start() method, whether called explicitly or implicitly (by
setting onmessage), starts the flow of messages: messages posted on
message ports are initially paused, so that they don't get dropped on
the floor before the script has had a chance to set up its handlers.
Now we don't read bytes from the underlying transport socket until the
message port transitions to the enabled state. This required the
following places to explicitly enable the message port, because now,
when it actually matters, we must do so, or otherwise sent messages will
get stuck:
- `onmessage` attribute setter in DedicatedWorkerGlobalScope, because
it implicitly sets the onmessage handler for the worker's underlying
port.
- Stream API operations where the message port enabling steps were
previously marked as FIXMEs.
Also push the onconnect event for the initial connection.
This still doesn't properly handle sending an onconnect event to a
pre-existing SharedWorkerGlobalScope with the same name for the same
origin, but it does give us a lot of WPT passes in the SharedWorker
category.
