When an exception is thrown during the processing of streaming WebAssembly,
`op_wasm_streaming_abort` is called. This op calls into V8, which synchronously
rejects the promise and calls into the promise rejection handler, if applicable.
But calling an op borrows the isolate's `JsRuntimeState` for the duration of the
op, which means it is borrowed when V8 calls into `promise_reject_callback`,
which tries to borrow it again, panicking.
This change changes `op_wasm_streaming_abort` from an op to a binding
(`Deno.core.abortWasmStreaming`). Although that binding must borrow the
`JsRuntimeState` in order to access the `WasmStreamingResource` stored in the
`OpTable`, it also takes ownership of that `WasmStreamingResource` instance,
which means it can drop any borrows of the `JsRuntimeState` before calling into
V8.
This allows resources to be "streams" by implementing read/write/shutdown. These streams are implicit since their nature (read/write/duplex) isn't known until called, but we could easily add another method to explicitly tag resources as streams.
`op_read/op_write/op_shutdown` are now builtin ops provided by `deno_core`
Note: this current implementation is simple & straightforward but it results in an additional alloc per read/write call
Closes #12556
WebAssembly modules compiled through `WebAssembly.compile()` and similar
non-streaming APIs don't have a URL associated to them, because they
have been compiled from a buffer source. In stack traces, V8 will use
a URL such as `wasm://wasm/d1c677ea`, with a hash of the module.
However, wasm modules compiled through streaming APIs, like
`WebAssembly.compileStreaming()`, do have a known URL, which can be
obtained from the `Response` object passed into the streaming APIs. And
as per the developer-facing display conventions in the WebAssembly
Web API spec, this URL should be used in stack traces. This change
implements that.
Async WebAssembly compilation was implemented by adding two
bindings: `set_wasm_streaming_callback`, which registered a callback to
be called whenever a streaming wasm compilation was started, and
`wasm_streaming_feed`, which let the JS callback modify the state of the
v8 wasm compiler.
`set_wasm_streaming_callback` cannot currently be implemented as
anything other than a binding, but `wasm_streaming_feed` does not really
need to use anything specific to bindings, and could indeed be
implemented as one or more ops. This PR does that, resulting in a
simplification of the relevant code.
There are three operations on the state of the v8 wasm compiler that
`wasm_streaming_feed` allowed: feeding new bytes into the compiler,
letting it know that there are no more bytes coming from the network,
and aborting the compilation. This PR provides `op_wasm_streaming_feed`
to feed new bytes into the compiler, and `op_wasm_streaming_abort` to
abort the compilation. It doesn't provide an op to let v8 know that the
response is finished, but closing the resource with `Deno.core.close()`
will achieve that.
* refactor(ops): return BadResource errors in ResourceTable calls
Instead of relying on callers to map Options to Results via `.ok_or_else(bad_resource_id)` at over 176 different call sites ...
This commit introduces primordials to deno_core. Primordials are a
frozen set of all intrinsic objects in the runtime. They are not
vulnerable to prototype pollution.
