Fixes #15136
Currently `UnsafeCallback` class' `ref()` and `unref()` methods rely on
the `event_loop_middleware` implementation in core. If even a single
`UnsafeCallback` is ref'ed, then the FFI event loop middleware will
always return `true` to signify that there may still be more work for
the event loop to do.
The middleware handling in core does not wait a moment to check again,
but will instead synchronously directly re-poll the event loop and
middlewares for more work. This becomes a live-loop.
This PR introduces a `Future` implementation for the `CallbackInfo`
struct that acts as the intermediary data storage between an
`UnsafeCallback` and the `libffi` C callback. Ref'ing a callback now
means calling an async op that binds to the `CallbackInfo` Future and
only resolves once the callback is unref'ed. The `libffi` C callback
will call the waker of this Future when it fires to make sure that the
main thread wakes up to receive the callback.
The return type checking for `"function"` type FFI values was incorrect
and presumed that functions were still being registered as objects
containing a "function" key.
While here, I also removed the whole return type checking logic as it
was needed for optionally creating BigInts on return when needed, but
serde_v8 does this automatically now (I think).
Mea culpa. Back when I re-introduced parameter and return value types to
FFI callbacks I failed to properly account for the change in match arm
logic. As a result, usize and isize parameters in FFI callbacks
currently enter the branch meant for void only.
This PR changes the match arms to all be explicit, making sure that void
is the only arm marked unreachable and that it stays that way.
This commit simplifies the TypeScript types used for interacting with Deno FFI. The basis is that types are now first grouped into logical wholes, NativeNumberType, NativeBigIntType etc. These wholes are combined into the NativeType and NativeResultType general types.
Additionally, this PR removes the { function: { parameters: [], result: "void" } } type declaration from parameters (and result types. Now functions are merely passed and returned as "function".
This commit adds support for unstable FFI
callbacks. A callback is registered using
the `Deno.UnsafeCallback` API.
The backing memory for the callback can
be disposed of using `Deno.UnsafeCallback#close`.
It is not safe to pass the callback after calling
close.
Callbacks from other than the isolate thread
are not supported.
Co-authored-by: Divy Srivastava <dj.srivastava23@gmail.com>
Co-authored-by: Bert Belder <bertbelder@gmail.com>
