Fixes #22995. Fixes #23000.
There were a handful of bugs here causing the hang (each with a
corresponding minimized test):
- We were canceling recv futures when `receiveMessageOnPort` was called,
but this caused the "receive loop" in the message port to exit. This was
due to the fact that `CancelHandle`s are never reset (i.e., once you
`cancel` a `CancelHandle`, it remains cancelled). That meant that after
`receieveMessageOnPort` was called, the subsequent calls to
`op_message_port_recv_message` would throw `Interrupted` exceptions, and
we would exit the loop.
The cancellation, however, isn't actually necessary.
`op_message_port_recv_message` only borrows the underlying port for long
enough to poll the receiver, so the borrow there could never overlap
with `op_message_port_recv_message_sync`.
- Calling `MessagePort.unref()` caused the "receive loop" in the message
port to exit. This was because we were setting
`messageEventListenerCount` to 0 on unref. Not only does that break the
counter when multiple `MessagePort`s are present in the same thread, but
we also exited the "receive loop" whenever the listener count was 0. I
assume this was to prevent the recv promise from keeping the event loop
open.
Instead of this, I chose to just unref the recv promise as needed to
control the event loop.
- The last bug causing the hang (which was a doozy to debug) ended up
being an unfortunate interaction between how we implement our
messageport "receive loop" and a pattern found in `npm:piscina` (which
angular uses). The gist of it is that piscina uses an atomic wait loop
along with `receiveMessageOnPort` in its worker threads, and as the
worker is getting started, the following incredibly convoluted series of
events occurs:
1. Parent sends a MessagePort `p` to worker
2. Parent sends a message `m` to the port `p`
3. Parent notifies the worker with `Atomics.notify` that a new message
is available
4. Worker receives message, adds "message" listener to port `p`
5. Adding the listener triggers `MessagePort.start()` on `p`
6. Receive loop in MessagePort.start receives the message `m`, but then
hits an await point and yields (before dispatching the "message" event)
7. Worker continues execution, starts the atomic wait loop, and
immediately receives the existing notification from the parent that a
message is available
8. Worker attempts to receive the new message `m` with
`receiveMessageOnPort`, but this returns `undefined` because the receive
loop already took the message in 6
9. Atomic wait loop continues to next iteration, waiting for the next
message with `Atomic.wait`
10. `Atomic.wait` blocks the worker thread, which prevents the receive
loop from continuing and dispatching the "message" event for the
received message
11. The parent waits for the worker to respond to the first message, and
waits
12. The thread can't make any more progress, and the whole process hangs
The fix I've chosen here (which I don't particularly love, but it works)
is to just delay the `MessagePort.start` call until the end of the event
loop turn, so that the atomic wait loop receives the message first. This
prevents the hang.
---
Those were the main issues causing the hang. There ended up being a few
other small bugs as well, namely `exit` being emitted multiple times,
and not patching up the message port when it's received by
`receiveMessageOnPort`.
This is a primordialization effort to improve resistance against users
tampering with the global `Object` prototype.
---------
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Closes https://github.com/denoland/deno/issues/23362
Previously we were panicking if there was a pending read on a
port and `receiveMessageOnPort` was called. This is now fixed
by cancelling the pending read, trying to read a message and
resuming reading in a loop.
`opAsync` requires a lookup by name on each async call. This is a
mechanical translation of all opAsync calls to ensureFastOps.
The `opAsync` API on Deno.core will be removed at a later time.
When we migrate to op-import-per-extension, we will want to ensure that
ops have one and only one place where they are imported. This tackles
the ops that are imported via `ensureFastOps`, but does not yet tackle
direct `ops` imports.
Landing ahead of https://github.com/denoland/deno_core/pull/393
This commit refactors how we access "core", "internals" and
"primordials" objects coming from `deno_core`, in our internal JavaScript code.
Instead of capturing them from "globalThis.__bootstrap" namespace, we
import them from recently added "ext:core/mod.js" file.
This addresses issue #19918.
## Issue description
Event messages have the wrong isTrusted value when they are not
triggered by user interaction, which differs from the browser. In
particular, all MessageEvents created by Deno have isTrusted set to
false, even though it should be true.
This is my first ever contribution to Deno, so I might be missing
something.
This should produce a little less garbage and using an object here
wasn't really required.
---------
Co-authored-by: Aapo Alasuutari <aapo.alasuutari@gmail.com>
Co-authored-by: Leo Kettmeir <crowlkats@toaxl.com>
This commit renames "deno_core::InternalModuleLoader" to
"ExtModuleLoader" and changes the specifiers used by the
modules loaded from this loader to "ext:".
"internal:" scheme was really ambiguous and it's more characters than
"ext:", which should result in slightly smaller snapshot size.
Closes https://github.com/denoland/deno/issues/18020
This PR refactors all internal js files (except core) to be written as
ES modules.
`__bootstrap`has been mostly replaced with static imports in form in
`internal:[path to file from repo root]`.
To specify if files are ESM, an `esm` method has been added to
`Extension`, similar to the `js` method.
A new ModuleLoader called `InternalModuleLoader` has been added to
enable the loading of internal specifiers, which is used in all
situations except when a snapshot is only loaded, and not a new one is
created from it.
---------
Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>
Updated third_party dlint to v0.37.0 for GitHub Actions. This PR
includes following changes:
* fix(prefer-primordials): Stop using array pattern assignments
* fix(prefer-primordials): Stop using global intrinsics except for
`SharedArrayBuffer`
* feat(guard-for-in): Apply new guard-for-in rule
Welcome to better optimised op calls! Currently opSync is called with parameters of every type and count. This most definitely makes the call megamorphic. Additionally, it seems that spread params leads to V8 not being able to optimise the calls quite as well (apparently Fast Calls cannot be used with spread params).
Monomorphising op calls should lead to some improved performance. Now that unwrapping of sync ops results is done on Rust side, this is pretty simple:
```
opSync("op_foo", param1, param2);
// -> turns to
ops.op_foo(param1, param2);
```
This means sync op calls are now just directly calling the native binding function. When V8 Fast API Calls are enabled, this will enable those to be called on the optimised path.
Monomorphising async ops likely requires using callbacks and is left as an exercise to the reader.
- Introduced optional callback for Deno.core.serialize API, that returns
cloning error if there is one.
- Removed try/catch in seralize structured clone function and throw error from
callback.
- Removed "Object with a getter that throws" assertion from WPT.
Currently all async ops are polled lazily, which means that op
initialization code is postponed until control is yielded to the event
loop. This has some weird consequences, e.g.
```js
let listener = Deno.listen(...);
let conn_promise = listener.accept();
listener.close();
// `BadResource` is thrown. A reasonable error would be `Interrupted`.
let conn = await conn_promise;
```
JavaScript promises are expected to be eagerly evaluated. This patch
makes ops actually do that.
