Several functions used for handling of dynamic imports and "import.meta"
object were not registered as external references and caused V8 to crash
during snapshotting. These functions are now registered as external refs
and aborts are no longer happening.
The `JsRuntimeState` struct stores a number of JS callbacks that are
used either in the event loop or when interacting with V8. Some of
these callback fields are vectors of callbacks, and therefore could
plausibly store at least one callback per realm. However, some of
those fields are `Option<v8::Global<v8::Function>>`, which would make
the callbacks set by a realm override the one that might have been set
by a different realm.
As it turns out, all of the current such optional callbacks
(`js_promise_reject_cb`, `js_format_exception_cb` and
`js_wasm_streaming_cb`) are only used from inside a realm, and
therefore this change makes it so such callbacks can only be set from
inside a realm, and will only affect that realm.
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.
Pull request #14019 enabled initial support for realms, but it did not
include support for async ops anywhere other than the main realm. The
main issue was that the `js_recv_cb` callback, which resolves promises
corresponding to async ops, was only set for the main realm, so async
ops in other realms would never resolve. Furthermore, promise ID's are
specific to each realm, which meant that async ops from other realms
would result in a wrong promise from the main realm being resolved.
This change creates a `ContextState` struct, similar to
`JsRuntimeState` but stored in a slot of each `v8::Context`, which
contains a `js_recv_cb` callback for each realm. Combined with a new
list of known realms, which stores them as `v8::Weak<v8::Context>`,
and a change in the `#[op]` macro to pass the current context to
`queue_async_op`, this makes it possible to send the results of
promises for different realms to their realm, and prevent the ID's
from getting mixed up.
Additionally, since promise ID's are no longer unique to the isolate,
having a single set of unrefed ops doesn't work. This change therefore
also moves `unrefed_ops` from `JsRuntimeState` to `ContextState`, and
adds the lengths of the unrefed op sets for all known realms to get
the total number of unrefed ops to compare in the event loop.
Co-authored-by: Luis Malheiro <luismalheiro@gmail.com>
Update "deno_core" to not forward rejection of top level module
if it was already handled by appropriate handlers.
Co-authored-by: Colin Ihrig cjihrig@gmail.com
The `op_event_loop_has_more_work` op, introduced in #14830, duplicates
code from `JsRuntime::poll_event_loop`. That PR also added the unused
method `JsRuntime::event_loop_has_work`, which is another duplication
of that same code, and which isn't used anywhere.
This change deduplicates this by renaming
`JsRuntime::event_loop_has_work` to `event_loop_pending_state`, and
making it the single place to determine what in the event loop is
pending. This result is then returned in a struct which is used both
in the event loop and in the `op_event_loop_has_more_work` op.
Currently almost every `JsRealm` method has a `&mut JsRuntime`
argument. This argument, however, is only used to get the runtime's
corresponding isolate. Given that a mutable reference to the
corresponding `v8::Isolate` can be reached from many more places than
a mutable reference to the `JsRuntime` (for example, by derefing a V8
scope), changing that will make `JsRealm` usable from many more places
than it currently is.
When a dynamically imported module gets resolved, any code that comes after an
await import() to that module will continue running. However, if that is the
last code in the evaluation of another dynamically imported module, that second
module will not resolve until the next iteration of the event loop, even though
it does not depend on the event loop at all.
When the event loop is being blocked by a long-running operation, such as a
long-running timer, or by an async op that might never end, such as with workers
or BroadcastChannels, that will result in the second dynamically imported module
not being resolved for a while, or ever.
This change fixes this by running the dynamic module loading steps in a loop
until no more dynamic modules can be resolved.
Keep a cache for source maps and source lines.
We sort of already had a cache argument for source map lookup
functions but we just passed an empty map instead of storing it.
Extended it to cache source line lookups as well and plugged it
into runtime state.
This commit adds "Deno.core.setFormatExceptionCallback" which
can be used to provide custom formatting for errors. It is useful
in cases when user throws something that is non-Error (eg.
a string, plain object, etc).
This reverts commit 10e50a1207
Alternative to #13217, IMO the tradeoffs made by #10786 aren't worth it.
It breaks abstractions (crates being self-contained, deno_core without snapshotting etc...) and causes pain points / gotchas for both embedders & devs for a relatively minimal gain in incremental build time ...
Closes #11030
This commit:
- removes "fmt_errors::PrettyJsError" in favor of "format_js_error" fn
- removes "deno_core::JsError::create" and
"deno_core::RuntimeOptions::js_error_create_fn"
- adds new option to "deno_runtime::ops::worker_host::init"
This commit adds tentative support for multiple realms in "deno_core".
It adds the "JsRealm" API that adds methods like "JsRuntime"'s
"handle_scope", "global_object" and "execute_script" specific to the realm.
The following transformations gradually faced by "JsError" have all been
moved up front to "JsError::from_v8_exception()":
- finding the first non-"deno:" source line;
- moving "JsError::script_resource_name" etc. into the first error stack
in case of syntax errors;
- source mapping "JsError::script_resource_name" etc. when wrapping
the error even though the frame locations are source mapped earlier;
- removing "JsError::{script_resource_name,line_number,start_column,end_column}"
entirely in favour of "js_error.frames.get(0)".
We also no longer pass a js-side callback to "core/02_error.js" from cli.
I avoided doing this on previous occasions because the source map lookups
were in an awkward place.
