MessagePort: implement disentanglement (#36654)

Implement
[disentangle](https://html.spec.whatwg.org/multipage/#disentangle)
Remove bespoke gc logic which now becomes unnecessary. 
Adds a wpt test that hits the "disentangle while in transfer" logic.
Updates streams code, fixing an error where disentanglement is
conditional on an error.

Test coverage: there are existing tests in
`/webmessaging/message-channels/close-event/explicitly-closed.tentative.window.js`
for the no transfer case, and the simple completed transfer case, and
this PR adds a test for the more complicated transfer in progress case.

Fix https://github.com/servo/servo/issues/36465

---------

Signed-off-by: gterzian <2792687+gterzian@users.noreply.github.com>
This commit is contained in:
Gregory Terzian 2025-04-30 12:49:38 +02:00 committed by GitHub
parent c46402e222
commit af5d665efa
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19 changed files with 356 additions and 191 deletions

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@ -4,7 +4,7 @@
//! Messages send from the ScriptThread to the Constellation.
use std::collections::{HashMap, VecDeque};
use std::collections::HashMap;
use std::fmt;
use base::Epoch;
@ -35,7 +35,9 @@ use webgpu_traits::{WebGPU, WebGPUAdapterResponse};
use webrender_api::ImageKey;
use crate::structured_data::{BroadcastMsg, StructuredSerializedData};
use crate::{LogEntry, MessagePortMsg, PortMessageTask, TraversalDirection, WindowSizeType};
use crate::{
LogEntry, MessagePortMsg, PortMessageTask, PortTransferInfo, TraversalDirection, WindowSizeType,
};
/// A Script to Constellation channel.
#[derive(Clone, Debug, Deserialize, Serialize)]
@ -470,7 +472,7 @@ pub enum ScriptToConstellationMessage {
/* The ids of ports transferred successfully */
Vec<MessagePortId>,
/* The ids, and buffers, of ports whose transfer failed */
HashMap<MessagePortId, VecDeque<PortMessageTask>>,
HashMap<MessagePortId, PortTransferInfo>,
),
/// A new message-port was created or transferred, with corresponding control-sender.
NewMessagePort(MessagePortRouterId, MessagePortId),
@ -482,10 +484,14 @@ pub enum ScriptToConstellationMessage {
RerouteMessagePort(MessagePortId, PortMessageTask),
/// A message-port was shipped, let the entangled port know.
MessagePortShipped(MessagePortId),
/// A message-port has been discarded by script.
RemoveMessagePort(MessagePortId),
/// Entangle two message-ports.
EntanglePorts(MessagePortId, MessagePortId),
/// Disentangle two message-ports.
/// The first is the initiator, the second the other port,
/// unless the message is sent to complete a disentanglement,
/// in which case the first one is the other port,
/// and the second is none.
DisentanglePorts(MessagePortId, Option<MessagePortId>),
/// A global has started managing broadcast-channels.
NewBroadcastChannelRouter(
BroadcastChannelRouterId,

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@ -157,18 +157,29 @@ pub struct PortMessageTask {
pub data: StructuredSerializedData,
}
/// The information needed by a global to process the transfer of a port.
#[derive(Debug, Deserialize, MallocSizeOf, Serialize)]
pub struct PortTransferInfo {
/// <https://html.spec.whatwg.org/multipage/#port-message-queue>
pub port_message_queue: VecDeque<PortMessageTask>,
/// A boolean indicating whether the port has been disentangled while in transfer,
/// if so, the disentanglement should be completed along with the transfer.
/// <https://html.spec.whatwg.org/multipage/#disentangle>
pub disentangled: bool,
}
/// Messages for communication between the constellation and a global managing ports.
#[derive(Debug, Deserialize, Serialize)]
#[allow(clippy::large_enum_variant)]
pub enum MessagePortMsg {
/// Complete the transfer for a batch of ports.
CompleteTransfer(HashMap<MessagePortId, VecDeque<PortMessageTask>>),
CompleteTransfer(HashMap<MessagePortId, PortTransferInfo>),
/// Complete the transfer of a single port,
/// whose transfer was pending because it had been requested
/// while a previous failed transfer was being rolled-back.
CompletePendingTransfer(MessagePortId, VecDeque<PortMessageTask>),
/// Remove a port, the entangled one doesn't exists anymore.
RemoveMessagePort(MessagePortId),
CompletePendingTransfer(MessagePortId, PortTransferInfo),
/// <https://html.spec.whatwg.org/multipage/#disentangle>
CompleteDisentanglement(MessagePortId),
/// Handle a new port-message-task.
NewTask(MessagePortId, PortMessageTask),
}

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@ -77,7 +77,12 @@ impl MessagePortImpl {
self.entangled_port
}
/// Entanged this port with another.
/// <https://html.spec.whatwg.org/multipage/#disentangle>
pub fn disentangle(&mut self) -> Option<MessagePortId> {
self.entangled_port.take()
}
/// <https://html.spec.whatwg.org/multipage/#entangle>
pub fn entangle(&mut self, other_id: MessagePortId) {
self.entangled_port = Some(other_id);
}