refactor(ext/ffi): split into multiple parts (#16950)

- [x] `dlfcn.rs` - `dlopen()`-related code.
- [x] `turbocall.rs` - Call trampoline JIT compiler. 
- [x] `repr.rs` - Pointer representation. Home of the UnsafePointerView
ops.
- [x] `symbol.rs` - Function symbol related code.
- [x] `callback.rs` - Home of `Deno.UnsafeCallback` ops.
- [x] `ir.rs` - Intermediate representation for values. Home of the
`NativeValue` type.
- [x] `call.rs` - Generic call ops. Home to everything related to
calling FFI symbols.
- [x] `static.rs` - static symbol support

I find easier to work with this setup, I eventually want to expand
TurboCall to unroll type conversion loop in generic calls, generate code
for individual symbols (lazy function pointers), etc.

1 files changed, 28 insertions, 2401 deletions

diff --git a/ext/ffi/lib.rs b/ext/ffi/lib.rs
index 7e7756c93..f3a906505 100644
--- a/ext/ffi/lib.rs
+++ b/ext/ffi/lib.rs
@@ -1,47 +1,41 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 
-use core::ptr::NonNull;
-use deno_core::anyhow::anyhow;
-use deno_core::error::generic_error;
-use deno_core::error::range_error;
-use deno_core::error::type_error;
 use deno_core::error::AnyError;
 use deno_core::futures::channel::mpsc;
-use deno_core::futures::Future;
 use deno_core::include_js_files;
-use deno_core::op;
-use deno_core::serde_json::Value;
-use deno_core::serde_v8;
 use deno_core::v8;
-use deno_core::CancelFuture;
-use deno_core::CancelHandle;
 use deno_core::Extension;
 use deno_core::OpState;
-use deno_core::Resource;
-use deno_core::ResourceId;
-use dlopen::raw::Library;
-use libffi::middle::Arg;
-use libffi::middle::Cif;
-use serde::Deserialize;
-use std::borrow::Cow;
+
 use std::cell::RefCell;
-use std::collections::HashMap;
-use std::ffi::c_void;
-use std::ffi::CStr;
-use std::future::IntoFuture;
 use std::mem::size_of;
 use std::os::raw::c_char;
 use std::os::raw::c_short;
 use std::path::Path;
-use std::path::PathBuf;
-use std::pin::Pin;
 use std::ptr;
 use std::rc::Rc;
-use std::sync::mpsc::sync_channel;
-use std::task::Poll;
-use std::task::Waker;
 
-mod fast_call;
+mod call;
+mod callback;
+mod dlfcn;
+mod ir;
+mod repr;
+mod r#static;
+mod symbol;
+mod turbocall;
+
+use call::op_ffi_call_nonblocking;
+use call::op_ffi_call_ptr;
+use call::op_ffi_call_ptr_nonblocking;
+use callback::op_ffi_unsafe_callback_create;
+use callback::op_ffi_unsafe_callback_ref;
+use callback::op_ffi_unsafe_callback_unref;
+use dlfcn::op_ffi_load;
+use dlfcn::ForeignFunction;
+use r#static::op_ffi_get_static;
+use repr::*;
+use symbol::NativeType;
+use symbol::Symbol;
 
 #[cfg(not(target_pointer_width = "64"))]
 compile_error!("platform not supported");
@@ -56,8 +50,8 @@ thread_local! {
   static LOCAL_ISOLATE_POINTER: RefCell<*const v8::Isolate> = RefCell::new(ptr::null());
 }
 
-const MAX_SAFE_INTEGER: isize = 9007199254740991;
-const MIN_SAFE_INTEGER: isize = -9007199254740991;
+pub(crate) const MAX_SAFE_INTEGER: isize = 9007199254740991;
+pub(crate) const MIN_SAFE_INTEGER: isize = -9007199254740991;
 
 pub struct Unstable(pub bool);
 
@@ -82,86 +76,11 @@ pub trait FfiPermissions {
   fn check(&mut self, path: Option<&Path>) -> Result<(), AnyError>;
 }
 
-#[derive(Clone)]
-struct Symbol {
-  cif: libffi::middle::Cif,
-  ptr: libffi::middle::CodePtr,
-  parameter_types: Vec<NativeType>,
-  result_type: NativeType,
-  can_callback: bool,
-}
-
-#[allow(clippy::non_send_fields_in_send_ty)]
-// SAFETY: unsafe trait must have unsafe implementation
-unsafe impl Send for Symbol {}
-// SAFETY: unsafe trait must have unsafe implementation
-unsafe impl Sync for Symbol {}
-
-#[derive(Clone)]
-struct PtrSymbol {
-  cif: libffi::middle::Cif,
-  ptr: libffi::middle::CodePtr,
-}
-
-impl PtrSymbol {
-  fn new(fn_ptr: usize, def: &ForeignFunction) -> Self {
-    let ptr = libffi::middle::CodePtr::from_ptr(fn_ptr as _);
-    let cif = libffi::middle::Cif::new(
-      def
-        .parameters
-        .clone()
-        .into_iter()
-        .map(libffi::middle::Type::from),
-      def.result.into(),
-    );
-
-    Self { cif, ptr }
-  }
-}
-
-#[allow(clippy::non_send_fields_in_send_ty)]
-// SAFETY: unsafe trait must have unsafe implementation
-unsafe impl Send for PtrSymbol {}
-// SAFETY: unsafe trait must have unsafe implementation
-unsafe impl Sync for PtrSymbol {}
-
-struct DynamicLibraryResource {
-  lib: Library,
-  symbols: HashMap<String, Box<Symbol>>,
-}
-
-impl Resource for DynamicLibraryResource {
-  fn name(&self) -> Cow<str> {
-    "dynamicLibrary".into()
-  }
+pub(crate) type PendingFfiAsyncWork = Box<dyn FnOnce()>;
 
-  fn close(self: Rc<Self>) {
-    drop(self)
-  }
-}
-
-impl DynamicLibraryResource {
-  fn get_static(&self, symbol: String) -> Result<*const c_void, AnyError> {
-    // By default, Err returned by this function does not tell
-    // which symbol wasn't exported. So we'll modify the error
-    // message to include the name of symbol.
-    //
-    // SAFETY: The obtained T symbol is the size of a pointer.
-    match unsafe { self.lib.symbol::<*const c_void>(&symbol) } {
-      Ok(value) => Ok(Ok(value)),
-      Err(err) => Err(generic_error(format!(
-        "Failed to register symbol {}: {}",
-        symbol, err
-      ))),
-    }?
-  }
-}
-
-type PendingFfiAsyncWork = Box<dyn FnOnce()>;
-
-struct FfiState {
-  async_work_sender: mpsc::UnboundedSender<PendingFfiAsyncWork>,
-  async_work_receiver: mpsc::UnboundedReceiver<PendingFfiAsyncWork>,
+pub(crate) struct FfiState {
+  pub(crate) async_work_sender: mpsc::UnboundedSender<PendingFfiAsyncWork>,
+  pub(crate) async_work_receiver: mpsc::UnboundedReceiver<PendingFfiAsyncWork>,
 }
 
 pub fn init<P: FfiPermissions + 'static>(unstable: bool) -> Extension {
@@ -237,2295 +156,3 @@ pub fn init<P: FfiPermissions + 'static>(unstable: bool) -> Extension {
     })
     .build()
 }
-
-/// Defines the accepted types that can be used as
-/// parameters and return values in FFI.
-#[derive(Clone, Copy, Debug, Deserialize, Eq, PartialEq)]
-#[serde(rename_all = "lowercase")]
-enum NativeType {
-  Void,
-  Bool,
-  U8,
-  I8,
-  U16,
-  I16,
-  U32,
-  I32,
-  U64,
-  I64,
-  USize,
-  ISize,
-  F32,
-  F64,
-  Pointer,
-  Buffer,
-  Function,
-}
-
-impl From<NativeType> for libffi::middle::Type {
-  fn from(native_type: NativeType) -> Self {
-    match native_type {
-      NativeType::Void => libffi::middle::Type::void(),
-      NativeType::U8 | NativeType::Bool => libffi::middle::Type::u8(),
-      NativeType::I8 => libffi::middle::Type::i8(),
-      NativeType::U16 => libffi::middle::Type::u16(),
-      NativeType::I16 => libffi::middle::Type::i16(),
-      NativeType::U32 => libffi::middle::Type::u32(),
-      NativeType::I32 => libffi::middle::Type::i32(),
-      NativeType::U64 => libffi::middle::Type::u64(),
-      NativeType::I64 => libffi::middle::Type::i64(),
-      NativeType::USize => libffi::middle::Type::usize(),
-      NativeType::ISize => libffi::middle::Type::isize(),
-      NativeType::F32 => libffi::middle::Type::f32(),
-      NativeType::F64 => libffi::middle::Type::f64(),
-      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
-        libffi::middle::Type::pointer()
-      }
-    }
-  }
-}
-
-/// Intermediate format for easy translation from NativeType + V8 value
-/// to libffi argument types.
-#[repr(C)]
-union NativeValue {
-  void_value: (),
-  bool_value: bool,
-  u8_value: u8,
-  i8_value: i8,
-  u16_value: u16,
-  i16_value: i16,
-  u32_value: u32,
-  i32_value: i32,
-  u64_value: u64,
-  i64_value: i64,
-  usize_value: usize,
-  isize_value: isize,
-  f32_value: f32,
-  f64_value: f64,
-  pointer: *mut c_void,
-}
-
-impl NativeValue {
-  unsafe fn as_arg(&self, native_type: NativeType) -> Arg {
-    match native_type {
-      NativeType::Void => unreachable!(),
-      NativeType::Bool => Arg::new(&self.bool_value),
-      NativeType::U8 => Arg::new(&self.u8_value),
-      NativeType::I8 => Arg::new(&self.i8_value),
-      NativeType::U16 => Arg::new(&self.u16_value),
-      NativeType::I16 => Arg::new(&self.i16_value),
-      NativeType::U32 => Arg::new(&self.u32_value),
-      NativeType::I32 => Arg::new(&self.i32_value),
-      NativeType::U64 => Arg::new(&self.u64_value),
-      NativeType::I64 => Arg::new(&self.i64_value),
-      NativeType::USize => Arg::new(&self.usize_value),
-      NativeType::ISize => Arg::new(&self.isize_value),
-      NativeType::F32 => Arg::new(&self.f32_value),
-      NativeType::F64 => Arg::new(&self.f64_value),
-      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
-        Arg::new(&self.pointer)
-      }
-    }
-  }
-
-  // SAFETY: native_type must correspond to the type of value represented by the union field
-  unsafe fn to_value(&self, native_type: NativeType) -> Value {
-    match native_type {
-      NativeType::Void => Value::Null,
-      NativeType::Bool => Value::from(self.bool_value),
-      NativeType::U8 => Value::from(self.u8_value),
-      NativeType::I8 => Value::from(self.i8_value),
-      NativeType::U16 => Value::from(self.u16_value),
-      NativeType::I16 => Value::from(self.i16_value),
-      NativeType::U32 => Value::from(self.u32_value),
-      NativeType::I32 => Value::from(self.i32_value),
-      NativeType::U64 => Value::from(self.u64_value),
-      NativeType::I64 => Value::from(self.i64_value),
-      NativeType::USize => Value::from(self.usize_value),
-      NativeType::ISize => Value::from(self.isize_value),
-      NativeType::F32 => Value::from(self.f32_value),
-      NativeType::F64 => Value::from(self.f64_value),
-      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
-        Value::from(self.pointer as usize)
-      }
-    }
-  }
-
-  // SAFETY: native_type must correspond to the type of value represented by the union field
-  #[inline]
-  unsafe fn to_v8<'scope>(
-    &self,
-    scope: &mut v8::HandleScope<'scope>,
-    native_type: NativeType,
-  ) -> serde_v8::Value<'scope> {
-    match native_type {
-      NativeType::Void => {
-        let local_value: v8::Local<v8::Value> = v8::undefined(scope).into();
-        local_value.into()
-      }
-      NativeType::Bool => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Boolean::new(scope, self.bool_value).into();
-        local_value.into()
-      }
-      NativeType::U8 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new_from_unsigned(scope, self.u8_value as u32).into();
-        local_value.into()
-      }
-      NativeType::I8 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new(scope, self.i8_value as i32).into();
-        local_value.into()
-      }
-      NativeType::U16 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new_from_unsigned(scope, self.u16_value as u32).into();
-        local_value.into()
-      }
-      NativeType::I16 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new(scope, self.i16_value as i32).into();
-        local_value.into()
-      }
-      NativeType::U32 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new_from_unsigned(scope, self.u32_value).into();
-        local_value.into()
-      }
-      NativeType::I32 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Integer::new(scope, self.i32_value).into();
-        local_value.into()
-      }
-      NativeType::U64 => {
-        let value = self.u64_value;
-        let local_value: v8::Local<v8::Value> =
-          if value > MAX_SAFE_INTEGER as u64 {
-            v8::BigInt::new_from_u64(scope, value).into()
-          } else {
-            v8::Number::new(scope, value as f64).into()
-          };
-        local_value.into()
-      }
-      NativeType::I64 => {
-        let value = self.i64_value;
-        let local_value: v8::Local<v8::Value> =
-          if value > MAX_SAFE_INTEGER as i64 || value < MIN_SAFE_INTEGER as i64
-          {
-            v8::BigInt::new_from_i64(scope, self.i64_value).into()
-          } else {
-            v8::Number::new(scope, value as f64).into()
-          };
-        local_value.into()
-      }
-      NativeType::USize => {
-        let value = self.usize_value;
-        let local_value: v8::Local<v8::Value> =
-          if value > MAX_SAFE_INTEGER as usize {
-            v8::BigInt::new_from_u64(scope, value as u64).into()
-          } else {
-            v8::Number::new(scope, value as f64).into()
-          };
-        local_value.into()
-      }
-      NativeType::ISize => {
-        let value = self.isize_value;
-        let local_value: v8::Local<v8::Value> =
-          if !(MIN_SAFE_INTEGER..=MAX_SAFE_INTEGER).contains(&value) {
-            v8::BigInt::new_from_i64(scope, self.isize_value as i64).into()
-          } else {
-            v8::Number::new(scope, value as f64).into()
-          };
-        local_value.into()
-      }
-      NativeType::F32 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Number::new(scope, self.f32_value as f64).into();
-        local_value.into()
-      }
-      NativeType::F64 => {
-        let local_value: v8::Local<v8::Value> =
-          v8::Number::new(scope, self.f64_value).into();
-        local_value.into()
-      }
-      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
-        let value = self.pointer as u64;
-        let local_value: v8::Local<v8::Value> =
-          if value > MAX_SAFE_INTEGER as u64 {
-            v8::BigInt::new_from_u64(scope, value).into()
-          } else {
-            v8::Number::new(scope, value as f64).into()
-          };
-        local_value.into()
-      }
-    }
-  }
-}
-
-// SAFETY: unsafe trait must have unsafe implementation
-unsafe impl Send for NativeValue {}
-
-#[derive(Deserialize, Debug)]
-#[serde(rename_all = "camelCase")]
-struct ForeignFunction {
-  name: Option<String>,
-  parameters: Vec<NativeType>,
-  result: NativeType,
-  #[serde(rename = "nonblocking")]
-  non_blocking: Option<bool>,
-  #[serde(rename = "callback")]
-  #[serde(default = "default_callback")]
-  callback: bool,
-}
-
-fn default_callback() -> bool {
-  false
-}
-
-// ForeignStatic's name and type fields are read and used by
-// serde_v8 to determine which variant a ForeignSymbol is.
-// They are not used beyond that and are thus marked with underscores.
-#[derive(Deserialize, Debug)]
-struct ForeignStatic {
-  #[serde(rename(deserialize = "name"))]
-  _name: Option<String>,
-  #[serde(rename(deserialize = "type"))]
-  _type: String,
-}
-
-#[derive(Deserialize, Debug)]
-#[serde(untagged)]
-enum ForeignSymbol {
-  ForeignFunction(ForeignFunction),
-  ForeignStatic(ForeignStatic),
-}
-
-#[derive(Deserialize, Debug)]
-struct FfiLoadArgs {
-  path: String,
-  symbols: HashMap<String, ForeignSymbol>,
-}
-
-// `path` is only used on Windows.
-#[allow(unused_variables)]
-pub(crate) fn format_error(e: dlopen::Error, path: String) -> String {
-  match e {
-    #[cfg(target_os = "windows")]
-    // This calls FormatMessageW with library path
-    // as replacement for the insert sequences.
-    // Unlike libstd which passes the FORMAT_MESSAGE_IGNORE_INSERTS
-    // flag without any arguments.
-    //
-    // https://github.com/denoland/deno/issues/11632
-    dlopen::Error::OpeningLibraryError(e) => {
-      use std::ffi::OsStr;
-      use std::os::windows::ffi::OsStrExt;
-      use winapi::shared::minwindef::DWORD;
-      use winapi::shared::winerror::ERROR_INSUFFICIENT_BUFFER;
-      use winapi::um::errhandlingapi::GetLastError;
-      use winapi::um::winbase::FormatMessageW;
-      use winapi::um::winbase::FORMAT_MESSAGE_ARGUMENT_ARRAY;
-      use winapi::um::winbase::FORMAT_MESSAGE_FROM_SYSTEM;
-      use winapi::um::winnt::LANG_SYSTEM_DEFAULT;
-      use winapi::um::winnt::MAKELANGID;
-      use winapi::um::winnt::SUBLANG_SYS_DEFAULT;
-
-      let err_num = match e.raw_os_error() {
-        Some(err_num) => err_num,
-        // This should never hit unless dlopen changes its error type.
-        None => return e.to_string(),
-      };
-
-      // Language ID (0x0800)
-      let lang_id =
-        MAKELANGID(LANG_SYSTEM_DEFAULT, SUBLANG_SYS_DEFAULT) as DWORD;
-
-      let mut buf = vec![0; 500];
-
-      let path = OsStr::new(&path)
-        .encode_wide()
-        .chain(Some(0).into_iter())
-        .collect::<Vec<_>>();
-
-      let arguments = [path.as_ptr()];
-
-      loop {
-        // SAFETY:
-        // winapi call to format the error message
-        let length = unsafe {
-          FormatMessageW(
-            FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY,
-            std::ptr::null_mut(),
-            err_num as DWORD,
-            lang_id as DWORD,
-            buf.as_mut_ptr(),
-            buf.len() as DWORD,
-            arguments.as_ptr() as _,
-          )
-        };
-
-        if length == 0 {
-          // SAFETY:
-          // winapi call to get the last error message
-          let err_num = unsafe { GetLastError() };
-          if err_num == ERROR_INSUFFICIENT_BUFFER {
-            buf.resize(buf.len() * 2, 0);
-            continue;
-          }
-
-          // Something went wrong, just return the original error.
-          return e.to_string();
-        }
-
-        let msg = String::from_utf16_lossy(&buf[..length as usize]);
-        return msg;
-      }
-    }
-    _ => e.to_string(),
-  }
-}
-
-#[op(v8)]
-fn op_ffi_load<FP, 'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: &mut deno_core::OpState,
-  args: FfiLoadArgs,
-) -> Result<(ResourceId, serde_v8::Value<'scope>), AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  let path = args.path;
-
-  check_unstable(state, "Deno.dlopen");
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(Some(&PathBuf::from(&path)))?;
-
-  let lib = Library::open(&path).map_err(|e| {
-    dlopen::Error::OpeningLibraryError(std::io::Error::new(
-      std::io::ErrorKind::Other,
-      format_error(e, path),
-    ))
-  })?;
-  let mut resource = DynamicLibraryResource {
-    lib,
-    symbols: HashMap::new(),
-  };
-  let obj = v8::Object::new(scope);
-
-  for (symbol_key, foreign_symbol) in args.symbols {
-    match foreign_symbol {
-      ForeignSymbol::ForeignStatic(_) => {
-        // No-op: Statics will be handled separately and are not part of the Rust-side resource.
-      }
-      ForeignSymbol::ForeignFunction(foreign_fn) => {
-        let symbol = match &foreign_fn.name {
-          Some(symbol) => symbol,
-          None => &symbol_key,
-        };
-        // By default, Err returned by this function does not tell
-        // which symbol wasn't exported. So we'll modify the error
-        // message to include the name of symbol.
-        let fn_ptr =
-          // SAFETY: The obtained T symbol is the size of a pointer.
-          match unsafe { resource.lib.symbol::<*const c_void>(symbol) } {
-            Ok(value) => Ok(value),
-            Err(err) => Err(generic_error(format!(
-              "Failed to register symbol {}: {}",
-              symbol, err
-            ))),
-          }?;
-        let ptr = libffi::middle::CodePtr::from_ptr(fn_ptr as _);
-        let cif = libffi::middle::Cif::new(
-          foreign_fn
-            .parameters
-            .clone()
-            .into_iter()
-            .map(libffi::middle::Type::from),
-          foreign_fn.result.into(),
-        );
-
-        let func_key = v8::String::new(scope, &symbol_key).unwrap();
-        let sym = Box::new(Symbol {
-          cif,
-          ptr,
-          parameter_types: foreign_fn.parameters,
-          result_type: foreign_fn.result,
-          can_callback: foreign_fn.callback,
-        });
-
-        resource.symbols.insert(symbol_key, sym.clone());
-        match foreign_fn.non_blocking {
-          // Generate functions for synchronous calls.
-          Some(false) | None => {
-            let function = make_sync_fn(scope, sym);
-            obj.set(scope, func_key.into(), function.into());
-          }
-          // This optimization is not yet supported for non-blocking calls.
-          _ => {}
-        };
-      }
-    }
-  }
-
-  let rid = state.resource_table.add(resource);
-  Ok((
-    rid,
-    serde_v8::Value {
-      v8_value: obj.into(),
-    },
-  ))
-}
-
-fn needs_unwrap(rv: NativeType) -> bool {
-  matches!(
-    rv,
-    NativeType::Function
-      | NativeType::Pointer
-      | NativeType::Buffer
-      | NativeType::I64
-      | NativeType::ISize
-      | NativeType::U64
-      | NativeType::USize
-  )
-}
-
-fn is_i64(rv: NativeType) -> bool {
-  matches!(rv, NativeType::I64 | NativeType::ISize)
-}
-
-// Create a JavaScript function for synchronous FFI call to
-// the given symbol.
-fn make_sync_fn<'s>(
-  scope: &mut v8::HandleScope<'s>,
-  sym: Box<Symbol>,
-) -> v8::Local<'s, v8::Function> {
-  let sym = Box::leak(sym);
-  let builder = v8::FunctionTemplate::builder(
-    |scope: &mut v8::HandleScope,
-     args: v8::FunctionCallbackArguments,
-     mut rv: v8::ReturnValue| {
-      let external: v8::Local<v8::External> = args.data().try_into().unwrap();
-      // SAFETY: The pointer will not be deallocated until the function is
-      // garbage collected.
-      let symbol = unsafe { &*(external.value() as *const Symbol) };
-      let needs_unwrap = match needs_unwrap(symbol.result_type) {
-        true => Some(args.get(symbol.parameter_types.len() as i32)),
-        false => None,
-      };
-      match ffi_call_sync(scope, args, symbol) {
-        Ok(result) => {
-          match needs_unwrap {
-            Some(v) => {
-              let view: v8::Local<v8::ArrayBufferView> = v.try_into().unwrap();
-              let backing_store =
-                view.buffer(scope).unwrap().get_backing_store();
-
-              if is_i64(symbol.result_type) {
-                // SAFETY: v8::SharedRef<v8::BackingStore> is similar to Arc<[u8]>,
-                // it points to a fixed continuous slice of bytes on the heap.
-                let bs = unsafe {
-                  &mut *(&backing_store[..] as *const _ as *mut [u8]
-                    as *mut i64)
-                };
-                // SAFETY: We already checked that type == I64
-                let value = unsafe { result.i64_value };
-                *bs = value;
-              } else {
-                // SAFETY: v8::SharedRef<v8::BackingStore> is similar to Arc<[u8]>,
-                // it points to a fixed continuous slice of bytes on the heap.
-                let bs = unsafe {
-                  &mut *(&backing_store[..] as *const _ as *mut [u8]
-                    as *mut u64)
-                };
-                // SAFETY: We checked that type == U64
-                let value = unsafe { result.u64_value };
-                *bs = value;
-              }
-            }
-            None => {
-              // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
-              let result = unsafe { result.to_v8(scope, symbol.result_type) };
-              rv.set(result.v8_value);
-            }
-          }
-        }
-        Err(err) => {
-          deno_core::_ops::throw_type_error(scope, err.to_string());
-        }
-      };
-    },
-  )
-  .data(v8::External::new(scope, sym as *mut Symbol as *mut _).into());
-
-  let mut fast_call_alloc = None;
-
-  let func = if fast_call::is_compatible(sym) {
-    let trampoline = fast_call::compile_trampoline(sym);
-    let func = builder.build_fast(
-      scope,
-      &fast_call::make_template(sym, &trampoline),
-      None,
-    );
-    fast_call_alloc = Some(Box::into_raw(Box::new(trampoline)));
-    func
-  } else {
-    builder.build(scope)
-  };
-  let func = func.get_function(scope).unwrap();
-
-  let weak = v8::Weak::with_finalizer(
-    scope,
-    func,
-    Box::new(move |_| {
-      // SAFETY: This is never called twice. pointer obtained
-      // from Box::into_raw, hence, satisfies memory layout requirements.
-      let _ = unsafe { Box::from_raw(sym) };
-      if let Some(fast_call_ptr) = fast_call_alloc {
-        // fast-call compiled trampoline is unmapped when the MMAP handle is dropped
-        // SAFETY: This is never called twice. pointer obtained
-        // from Box::into_raw, hence, satisfies memory layout requirements.
-        let _ = unsafe { Box::from_raw(fast_call_ptr) };
-      }
-    }),
-  );
-
-  weak.to_local(scope).unwrap()
-}
-
-#[inline]
-fn ffi_parse_bool_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let bool_value = v8::Local::<v8::Boolean>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI u8 type, expected boolean"))?
-    .is_true();
-  Ok(NativeValue { bool_value })
-}
-
-#[inline]
-fn ffi_parse_u8_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let u8_value = v8::Local::<v8::Uint32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI u8 type, expected unsigned integer"))?
-    .value() as u8;
-  Ok(NativeValue { u8_value })
-}
-
-#[inline]
-fn ffi_parse_i8_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let i8_value = v8::Local::<v8::Int32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI i8 type, expected integer"))?
-    .value() as i8;
-  Ok(NativeValue { i8_value })
-}
-
-#[inline]
-fn ffi_parse_u16_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let u16_value = v8::Local::<v8::Uint32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI u16 type, expected unsigned integer"))?
-    .value() as u16;
-  Ok(NativeValue { u16_value })
-}
-
-#[inline]
-fn ffi_parse_i16_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let i16_value = v8::Local::<v8::Int32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI i16 type, expected integer"))?
-    .value() as i16;
-  Ok(NativeValue { i16_value })
-}
-
-#[inline]
-fn ffi_parse_u32_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let u32_value = v8::Local::<v8::Uint32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI u32 type, expected unsigned integer"))?
-    .value() as u32;
-  Ok(NativeValue { u32_value })
-}
-
-#[inline]
-fn ffi_parse_i32_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let i32_value = v8::Local::<v8::Int32>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI i32 type, expected integer"))?
-    .value() as i32;
-  Ok(NativeValue { i32_value })
-}
-
-#[inline]
-fn ffi_parse_u64_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
-  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
-  let u64_value: u64 = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg)
-  {
-    value.u64_value().0
-  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-    value.integer_value(scope).unwrap() as u64
-  } else {
-    return Err(type_error(
-      "Invalid FFI u64 type, expected unsigned integer",
-    ));
-  };
-  Ok(NativeValue { u64_value })
-}
-
-#[inline]
-fn ffi_parse_i64_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
-  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
-  let i64_value: i64 = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg)
-  {
-    value.i64_value().0
-  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-    value.integer_value(scope).unwrap() as i64
-  } else {
-    return Err(type_error("Invalid FFI i64 type, expected integer"));
-  };
-  Ok(NativeValue { i64_value })
-}
-
-#[inline]
-fn ffi_parse_usize_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
-  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
-  let usize_value: usize =
-    if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
-      value.u64_value().0 as usize
-    } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-      value.integer_value(scope).unwrap() as usize
-    } else {
-      return Err(type_error("Invalid FFI usize type, expected integer"));
-    };
-  Ok(NativeValue { usize_value })
-}
-
-#[inline]
-fn ffi_parse_isize_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, so optimise slow call for this case.
-  // 2. Number: Common, supported by Fast API, so let that be the optimal case.
-  let isize_value: isize =
-    if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
-      value.i64_value().0 as isize
-    } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-      value.integer_value(scope).unwrap() as isize
-    } else {
-      return Err(type_error("Invalid FFI isize type, expected integer"));
-    };
-  Ok(NativeValue { isize_value })
-}
-
-#[inline]
-fn ffi_parse_f32_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let f32_value = v8::Local::<v8::Number>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI f32 type, expected number"))?
-    .value() as f32;
-  Ok(NativeValue { f32_value })
-}
-
-#[inline]
-fn ffi_parse_f64_arg(
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  let f64_value = v8::Local::<v8::Number>::try_from(arg)
-    .map_err(|_| type_error("Invalid FFI f64 type, expected number"))?
-    .value() as f64;
-  Ok(NativeValue { f64_value })
-}
-
-#[inline]
-fn ffi_parse_pointer_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, optimise this case.
-  // 2. Number: Common and supported by Fast API.
-  // 3. Null: Very uncommon / can be represented by a 0.
-  let pointer = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
-    value.u64_value().0 as usize as *mut c_void
-  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-    value.integer_value(scope).unwrap() as usize as *mut c_void
-  } else if arg.is_null() {
-    ptr::null_mut()
-  } else {
-    return Err(type_error(
-      "Invalid FFI pointer type, expected null, integer or BigInt",
-    ));
-  };
-  Ok(NativeValue { pointer })
-}
-
-#[inline]
-fn ffi_parse_buffer_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. ArrayBuffer: Fairly common and not supported by Fast API, optimise this case.
-  // 2. ArrayBufferView: Common and supported by Fast API
-  // 5. Null: Very uncommon / can be represented by a 0.
-
-  let pointer = if let Ok(value) = v8::Local::<v8::ArrayBuffer>::try_from(arg) {
-    if let Some(non_null) = value.data() {
-      non_null.as_ptr()
-    } else {
-      ptr::null_mut()
-    }
-  } else if let Ok(value) = v8::Local::<v8::ArrayBufferView>::try_from(arg) {
-    let byte_offset = value.byte_offset();
-    let pointer = value
-      .buffer(scope)
-      .ok_or_else(|| {
-        type_error("Invalid FFI ArrayBufferView, expected data in the buffer")
-      })?
-      .data();
-    if let Some(non_null) = pointer {
-      // SAFETY: Pointer is non-null, and V8 guarantees that the byte_offset
-      // is within the buffer backing store.
-      unsafe { non_null.as_ptr().add(byte_offset) }
-    } else {
-      ptr::null_mut()
-    }
-  } else if arg.is_null() {
-    ptr::null_mut()
-  } else {
-    return Err(type_error(
-      "Invalid FFI buffer type, expected null, ArrayBuffer, or ArrayBufferView",
-    ));
-  };
-  Ok(NativeValue { pointer })
-}
-
-#[inline]
-fn ffi_parse_function_arg(
-  scope: &mut v8::HandleScope,
-  arg: v8::Local<v8::Value>,
-) -> Result<NativeValue, AnyError> {
-  // Order of checking:
-  // 1. BigInt: Uncommon and not supported by Fast API, optimise this case.
-  // 2. Number: Common and supported by Fast API, optimise this case as second.
-  // 3. Null: Very uncommon / can be represented by a 0.
-  let pointer = if let Ok(value) = v8::Local::<v8::BigInt>::try_from(arg) {
-    value.u64_value().0 as usize as *mut c_void
-  } else if let Ok(value) = v8::Local::<v8::Number>::try_from(arg) {
-    value.integer_value(scope).unwrap() as usize as *mut c_void
-  } else if arg.is_null() {
-    ptr::null_mut()
-  } else {
-    return Err(type_error(
-      "Invalid FFI function type, expected null, integer, or BigInt",
-    ));
-  };
-  Ok(NativeValue { pointer })
-}
-
-fn ffi_parse_args<'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  args: serde_v8::Value<'scope>,
-  parameter_types: &[NativeType],
-) -> Result<Vec<NativeValue>, AnyError>
-where
-  'scope: 'scope,
-{
-  if parameter_types.is_empty() {
-    return Ok(vec![]);
-  }
-
-  let args = v8::Local::<v8::Array>::try_from(args.v8_value)
-    .map_err(|_| type_error("Invalid FFI parameters, expected Array"))?;
-  let mut ffi_args: Vec<NativeValue> =
-    Vec::with_capacity(parameter_types.len());
-
-  for (index, native_type) in parameter_types.iter().enumerate() {
-    let value = args.get_index(scope, index as u32).unwrap();
-    match native_type {
-      NativeType::Bool => {
-        ffi_args.push(ffi_parse_bool_arg(value)?);
-      }
-      NativeType::U8 => {
-        ffi_args.push(ffi_parse_u8_arg(value)?);
-      }
-      NativeType::I8 => {
-        ffi_args.push(ffi_parse_i8_arg(value)?);
-      }
-      NativeType::U16 => {
-        ffi_args.push(ffi_parse_u16_arg(value)?);
-      }
-      NativeType::I16 => {
-        ffi_args.push(ffi_parse_i16_arg(value)?);
-      }
-      NativeType::U32 => {
-        ffi_args.push(ffi_parse_u32_arg(value)?);
-      }
-      NativeType::I32 => {
-        ffi_args.push(ffi_parse_i32_arg(value)?);
-      }
-      NativeType::U64 => {
-        ffi_args.push(ffi_parse_u64_arg(scope, value)?);
-      }
-      NativeType::I64 => {
-        ffi_args.push(ffi_parse_i64_arg(scope, value)?);
-      }
-      NativeType::USize => {
-        ffi_args.push(ffi_parse_usize_arg(scope, value)?);
-      }
-      NativeType::ISize => {
-        ffi_args.push(ffi_parse_isize_arg(scope, value)?);
-      }
-      NativeType::F32 => {
-        ffi_args.push(ffi_parse_f32_arg(value)?);
-      }
-      NativeType::F64 => {
-        ffi_args.push(ffi_parse_f64_arg(value)?);
-      }
-      NativeType::Buffer => {
-        ffi_args.push(ffi_parse_buffer_arg(scope, value)?);
-      }
-      NativeType::Pointer => {
-        ffi_args.push(ffi_parse_pointer_arg(scope, value)?);
-      }
-      NativeType::Function => {
-        ffi_args.push(ffi_parse_function_arg(scope, value)?);
-      }
-      NativeType::Void => {
-        unreachable!();
-      }
-    }
-  }
-
-  Ok(ffi_args)
-}
-
-// A one-off synchronous FFI call.
-fn ffi_call_sync<'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  args: v8::FunctionCallbackArguments,
-  symbol: &Symbol,
-) -> Result<NativeValue, AnyError>
-where
-  'scope: 'scope,
-{
-  let Symbol {
-    parameter_types,
-    result_type,
-    cif,
-    ptr: fun_ptr,
-    ..
-  } = symbol;
-  let mut ffi_args: Vec<NativeValue> =
-    Vec::with_capacity(parameter_types.len());
-
-  for (index, native_type) in parameter_types.iter().enumerate() {
-    let value = args.get(index as i32);
-    match native_type {
-      NativeType::Bool => {
-        ffi_args.push(ffi_parse_bool_arg(value)?);
-      }
-      NativeType::U8 => {
-        ffi_args.push(ffi_parse_u8_arg(value)?);
-      }
-      NativeType::I8 => {
-        ffi_args.push(ffi_parse_i8_arg(value)?);
-      }
-      NativeType::U16 => {
-        ffi_args.push(ffi_parse_u16_arg(value)?);
-      }
-      NativeType::I16 => {
-        ffi_args.push(ffi_parse_i16_arg(value)?);
-      }
-      NativeType::U32 => {
-        ffi_args.push(ffi_parse_u32_arg(value)?);
-      }
-      NativeType::I32 => {
-        ffi_args.push(ffi_parse_i32_arg(value)?);
-      }
-      NativeType::U64 => {
-        ffi_args.push(ffi_parse_u64_arg(scope, value)?);
-      }
-      NativeType::I64 => {
-        ffi_args.push(ffi_parse_i64_arg(scope, value)?);
-      }
-      NativeType::USize => {
-        ffi_args.push(ffi_parse_usize_arg(scope, value)?);
-      }
-      NativeType::ISize => {
-        ffi_args.push(ffi_parse_isize_arg(scope, value)?);
-      }
-      NativeType::F32 => {
-        ffi_args.push(ffi_parse_f32_arg(value)?);
-      }
-      NativeType::F64 => {
-        ffi_args.push(ffi_parse_f64_arg(value)?);
-      }
-      NativeType::Buffer => {
-        ffi_args.push(ffi_parse_buffer_arg(scope, value)?);
-      }
-      NativeType::Pointer => {
-        ffi_args.push(ffi_parse_pointer_arg(scope, value)?);
-      }
-      NativeType::Function => {
-        ffi_args.push(ffi_parse_function_arg(scope, value)?);
-      }
-      NativeType::Void => {
-        unreachable!();
-      }
-    }
-  }
-  let call_args: Vec<Arg> = ffi_args.iter().map(Arg::new).collect();
-  // SAFETY: types in the `Cif` match the actual calling convention and
-  // types of symbol.
-  unsafe {
-    Ok(match result_type {
-      NativeType::Void => NativeValue {
-        void_value: cif.call::<()>(*fun_ptr, &call_args),
-      },
-      NativeType::Bool => NativeValue {
-        bool_value: cif.call::<bool>(*fun_ptr, &call_args),
-      },
-      NativeType::U8 => NativeValue {
-        u8_value: cif.call::<u8>(*fun_ptr, &call_args),
-      },
-      NativeType::I8 => NativeValue {
-        i8_value: cif.call::<i8>(*fun_ptr, &call_args),
-      },
-      NativeType::U16 => NativeValue {
-        u16_value: cif.call::<u16>(*fun_ptr, &call_args),
-      },
-      NativeType::I16 => NativeValue {
-        i16_value: cif.call::<i16>(*fun_ptr, &call_args),
-      },
-      NativeType::U32 => NativeValue {
-        u32_value: cif.call::<u32>(*fun_ptr, &call_args),
-      },
-      NativeType::I32 => NativeValue {
-        i32_value: cif.call::<i32>(*fun_ptr, &call_args),
-      },
-      NativeType::U64 => NativeValue {
-        u64_value: cif.call::<u64>(*fun_ptr, &call_args),
-      },
-      NativeType::I64 => NativeValue {
-        i64_value: cif.call::<i64>(*fun_ptr, &call_args),
-      },
-      NativeType::USize => NativeValue {
-        usize_value: cif.call::<usize>(*fun_ptr, &call_args),
-      },
-      NativeType::ISize => NativeValue {
-        isize_value: cif.call::<isize>(*fun_ptr, &call_args),
-      },
-      NativeType::F32 => NativeValue {
-        f32_value: cif.call::<f32>(*fun_ptr, &call_args),
-      },
-      NativeType::F64 => NativeValue {
-        f64_value: cif.call::<f64>(*fun_ptr, &call_args),
-      },
-      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
-        NativeValue {
-          pointer: cif.call::<*mut c_void>(*fun_ptr, &call_args),
-        }
-      }
-    })
-  }
-}
-
-fn ffi_call(
-  call_args: Vec<NativeValue>,
-  cif: &libffi::middle::Cif,
-  fun_ptr: libffi::middle::CodePtr,
-  parameter_types: &[NativeType],
-  result_type: NativeType,
-) -> Result<NativeValue, AnyError> {
-  let call_args: Vec<Arg> = call_args
-    .iter()
-    .enumerate()
-    .map(|(index, ffi_arg)| {
-      // SAFETY: the union field is initialized
-      unsafe { ffi_arg.as_arg(*parameter_types.get(index).unwrap()) }
-    })
-    .collect();
-
-  // SAFETY: types in the `Cif` match the actual calling convention and
-  // types of symbol.
-  unsafe {
-    Ok(match result_type {
-      NativeType::Void => NativeValue {
-        void_value: cif.call::<()>(fun_ptr, &call_args),
-      },
-      NativeType::Bool => NativeValue {
-        bool_value: cif.call::<bool>(fun_ptr, &call_args),
-      },
-      NativeType::U8 => NativeValue {
-        u8_value: cif.call::<u8>(fun_ptr, &call_args),
-      },
-      NativeType::I8 => NativeValue {
-        i8_value: cif.call::<i8>(fun_ptr, &call_args),
-      },
-      NativeType::U16 => NativeValue {
-        u16_value: cif.call::<u16>(fun_ptr, &call_args),
-      },
-      NativeType::I16 => NativeValue {
-        i16_value: cif.call::<i16>(fun_ptr, &call_args),
-      },
-      NativeType::U32 => NativeValue {
-        u32_value: cif.call::<u32>(fun_ptr, &call_args),
-      },
-      NativeType::I32 => NativeValue {
-        i32_value: cif.call::<i32>(fun_ptr, &call_args),
-      },
-      NativeType::U64 => NativeValue {
-        u64_value: cif.call::<u64>(fun_ptr, &call_args),
-      },
-      NativeType::I64 => NativeValue {
-        i64_value: cif.call::<i64>(fun_ptr, &call_args),
-      },
-      NativeType::USize => NativeValue {
-        usize_value: cif.call::<usize>(fun_ptr, &call_args),
-      },
-      NativeType::ISize => NativeValue {
-        isize_value: cif.call::<isize>(fun_ptr, &call_args),
-      },
-      NativeType::F32 => NativeValue {
-        f32_value: cif.call::<f32>(fun_ptr, &call_args),
-      },
-      NativeType::F64 => NativeValue {
-        f64_value: cif.call::<f64>(fun_ptr, &call_args),
-      },
-      NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
-        NativeValue {
-          pointer: cif.call::<*mut c_void>(fun_ptr, &call_args),
-        }
-      }
-    })
-  }
-}
-
-struct UnsafeCallbackResource {
-  cancel: Rc<CancelHandle>,
-  // Closure is never directly touched, but it keeps the C callback alive
-  // until `close()` method is called.
-  #[allow(dead_code)]
-  closure: libffi::middle::Closure<'static>,
-  info: *mut CallbackInfo,
-}
-
-impl Resource for UnsafeCallbackResource {
-  fn name(&self) -> Cow<str> {
-    "unsafecallback".into()
-  }
-
-  fn close(self: Rc<Self>) {
-    self.cancel.cancel();
-    // SAFETY: This drops the closure and the callback info associated with it.
-    // Any retained function pointers to the closure become dangling pointers.
-    // It is up to the user to know that it is safe to call the `close()` on the
-    // UnsafeCallback instance.
-    unsafe {
-      let info = Box::from_raw(self.info);
-      let isolate = info.isolate.as_mut().unwrap();
-      let _ = v8::Global::from_raw(isolate, info.callback);
-      let _ = v8::Global::from_raw(isolate, info.context);
-    }
-  }
-}
-
-struct CallbackInfo {
-  pub parameters: Vec<NativeType>,
-  pub result: NativeType,
-  pub async_work_sender: mpsc::UnboundedSender<PendingFfiAsyncWork>,
-  pub callback: NonNull<v8::Function>,
-  pub context: NonNull<v8::Context>,
-  pub isolate: *mut v8::Isolate,
-  pub waker: Option<Waker>,
-}
-
-unsafe extern "C" fn deno_ffi_callback(
-  _cif: &libffi::low::ffi_cif,
-  result: &mut c_void,
-  args: *const *const c_void,
-  info: &CallbackInfo,
-) {
-  LOCAL_ISOLATE_POINTER.with(|s| {
-    if ptr::eq(*s.borrow(), info.isolate) {
-      // Own isolate thread, okay to call directly
-      do_ffi_callback(info, result, args);
-    } else {
-      let async_work_sender = &info.async_work_sender;
-      // SAFETY: Safe as this function blocks until `do_ffi_callback` completes and a response message is received.
-      let result: &'static mut c_void = std::mem::transmute(result);
-      let info: &'static CallbackInfo = std::mem::transmute(info);
-      let (response_sender, response_receiver) = sync_channel::<()>(0);
-      let fut = Box::new(move || {
-        do_ffi_callback(info, result, args);
-        response_sender.send(()).unwrap();
-      });
-      async_work_sender.unbounded_send(fut).unwrap();
-      if let Some(waker) = info.waker.as_ref() {
-        // Make sure event loop wakes up to receive our message before we start waiting for a response.
-        waker.wake_by_ref();
-      }
-      response_receiver.recv().unwrap();
-    }
-  });
-}
-
-unsafe fn do_ffi_callback(
-  info: &CallbackInfo,
-  result: &mut c_void,
-  args: *const *const c_void,
-) {
-  let callback: NonNull<v8::Function> = info.callback;
-  let context: NonNull<v8::Context> = info.context;
-  let isolate: *mut v8::Isolate = info.isolate;
-  let isolate = &mut *isolate;
-  let callback = v8::Global::from_raw(isolate, callback);
-  let context = std::mem::transmute::<
-    NonNull<v8::Context>,
-    v8::Local<v8::Context>,
-  >(context);
-  // Call from main thread. If this callback is being triggered due to a
-  // function call coming from Deno itself, then this callback will build
-  // ontop of that stack.
-  // If this callback is being triggered outside of Deno (for example from a
-  // signal handler) then this will either create an empty new stack if
-  // Deno currently has nothing running and is waiting for promises to resolve,
-  // or will (very incorrectly) build ontop of whatever stack exists.
-  // The callback will even be called through from a `while (true)` liveloop, but
-  // it somehow cannot change the values that the loop sees, even if they both
-  // refer the same `let bool_value`.
-  let mut cb_scope = v8::CallbackScope::new(context);
-  let scope = &mut v8::HandleScope::new(&mut cb_scope);
-  let func = callback.open(scope);
-  let result = result as *mut c_void;
-  let vals: &[*const c_void] =
-    std::slice::from_raw_parts(args, info.parameters.len() as usize);
-
-  let mut params: Vec<v8::Local<v8::Value>> = vec![];
-  for (native_type, val) in info.parameters.iter().zip(vals) {
-    let value: v8::Local<v8::Value> = match native_type {
-      NativeType::Bool => {
-        let value = *((*val) as *const bool);
-        v8::Boolean::new(scope, value).into()
-      }
-      NativeType::F32 => {
-        let value = *((*val) as *const f32);
-        v8::Number::new(scope, value as f64).into()
-      }
-      NativeType::F64 => {
-        let value = *((*val) as *const f64);
-        v8::Number::new(scope, value).into()
-      }
-      NativeType::I8 => {
-        let value = *((*val) as *const i8);
-        v8::Integer::new(scope, value as i32).into()
-      }
-      NativeType::U8 => {
-        let value = *((*val) as *const u8);
-        v8::Integer::new_from_unsigned(scope, value as u32).into()
-      }
-      NativeType::I16 => {
-        let value = *((*val) as *const i16);
-        v8::Integer::new(scope, value as i32).into()
-      }
-      NativeType::U16 => {
-        let value = *((*val) as *const u16);
-        v8::Integer::new_from_unsigned(scope, value as u32).into()
-      }
-      NativeType::I32 => {
-        let value = *((*val) as *const i32);
-        v8::Integer::new(scope, value).into()
-      }
-      NativeType::U32 => {
-        let value = *((*val) as *const u32);
-        v8::Integer::new_from_unsigned(scope, value).into()
-      }
-      NativeType::I64 | NativeType::ISize => {
-        let result = *((*val) as *const i64);
-        if result > MAX_SAFE_INTEGER as i64 || result < MIN_SAFE_INTEGER as i64
-        {
-          v8::BigInt::new_from_i64(scope, result).into()
-        } else {
-          v8::Number::new(scope, result as f64).into()
-        }
-      }
-      NativeType::U64 | NativeType::USize => {
-        let result = *((*val) as *const u64);
-        if result > MAX_SAFE_INTEGER as u64 {
-          v8::BigInt::new_from_u64(scope, result).into()
-        } else {
-          v8::Number::new(scope, result as f64).into()
-        }
-      }
-      NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
-        let result = *((*val) as *const usize);
-        if result > MAX_SAFE_INTEGER as usize {
-          v8::BigInt::new_from_u64(scope, result as u64).into()
-        } else {
-          v8::Number::new(scope, result as f64).into()
-        }
-      }
-      NativeType::Void => unreachable!(),
-    };
-    params.push(value);
-  }
-
-  let recv = v8::undefined(scope);
-  let call_result = func.call(scope, recv.into(), &params);
-  std::mem::forget(callback);
-
-  if call_result.is_none() {
-    // JS function threw an exception. Set the return value to zero and return.
-    // The exception continue propagating up the call chain when the event loop
-    // resumes.
-    match info.result {
-      NativeType::Bool => {
-        *(result as *mut bool) = false;
-      }
-      NativeType::U32 | NativeType::I32 => {
-        // zero is equal for signed and unsigned alike
-        *(result as *mut u32) = 0;
-      }
-      NativeType::F32 => {
-        *(result as *mut f32) = 0.0;
-      }
-      NativeType::F64 => {
-        *(result as *mut f64) = 0.0;
-      }
-      NativeType::U8 | NativeType::I8 => {
-        // zero is equal for signed and unsigned alike
-        *(result as *mut u8) = 0;
-      }
-      NativeType::U16 | NativeType::I16 => {
-        // zero is equal for signed and unsigned alike
-        *(result as *mut u16) = 0;
-      }
-      NativeType::Pointer
-      | NativeType::Buffer
-      | NativeType::Function
-      | NativeType::U64
-      | NativeType::I64 => {
-        *(result as *mut usize) = 0;
-      }
-      NativeType::Void => {
-        // nop
-      }
-      _ => {
-        unreachable!();
-      }
-    };
-
-    return;
-  }
-  let value = call_result.unwrap();
-
-  match info.result {
-    NativeType::Bool => {
-      let value = if let Ok(value) = v8::Local::<v8::Boolean>::try_from(value) {
-        value.is_true()
-      } else {
-        value.boolean_value(scope)
-      };
-      *(result as *mut bool) = value;
-    }
-    NativeType::I32 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as i32
-      } else {
-        // Fallthrough, probably UB.
-        value
-          .int32_value(scope)
-          .expect("Unable to deserialize result parameter.") as i32
-      };
-      *(result as *mut i32) = value;
-    }
-    NativeType::F32 => {
-      let value = if let Ok(value) = v8::Local::<v8::Number>::try_from(value) {
-        value.value() as f32
-      } else {
-        // Fallthrough, probably UB.
-        value
-          .number_value(scope)
-          .expect("Unable to deserialize result parameter.") as f32
-      };
-      *(result as *mut f32) = value;
-    }
-    NativeType::F64 => {
-      let value = if let Ok(value) = v8::Local::<v8::Number>::try_from(value) {
-        value.value()
-      } else {
-        // Fallthrough, probably UB.
-        value
-          .number_value(scope)
-          .expect("Unable to deserialize result parameter.")
-      };
-      *(result as *mut f64) = value;
-    }
-    NativeType::Pointer | NativeType::Buffer | NativeType::Function => {
-      let pointer = if let Ok(value) =
-        v8::Local::<v8::ArrayBufferView>::try_from(value)
-      {
-        let byte_offset = value.byte_offset();
-        let backing_store = value
-          .buffer(scope)
-          .expect("Unable to deserialize result parameter.")
-          .get_backing_store();
-        &backing_store[byte_offset..] as *const _ as *const u8
-      } else if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
-        value.u64_value().0 as usize as *const u8
-      } else if let Ok(value) = v8::Local::<v8::ArrayBuffer>::try_from(value) {
-        let backing_store = value.get_backing_store();
-        &backing_store[..] as *const _ as *const u8
-      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as usize as *const u8
-      } else if value.is_null() {
-        ptr::null()
-      } else {
-        // Fallthrough: Probably someone returned a number but this could
-        // also be eg. a string. This is essentially UB.
-        value
-          .integer_value(scope)
-          .expect("Unable to deserialize result parameter.") as usize
-          as *const u8
-      };
-      *(result as *mut *const u8) = pointer;
-    }
-    NativeType::I8 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as i8
-      } else {
-        // Fallthrough, essentially UB.
-        value
-          .int32_value(scope)
-          .expect("Unable to deserialize result parameter.") as i8
-      };
-      *(result as *mut i8) = value;
-    }
-    NativeType::U8 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as u8
-      } else {
-        // Fallthrough, essentially UB.
-        value
-          .uint32_value(scope)
-          .expect("Unable to deserialize result parameter.") as u8
-      };
-      *(result as *mut u8) = value;
-    }
-    NativeType::I16 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as i16
-      } else {
-        // Fallthrough, essentially UB.
-        value
-          .int32_value(scope)
-          .expect("Unable to deserialize result parameter.") as i16
-      };
-      *(result as *mut i16) = value;
-    }
-    NativeType::U16 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as u16
-      } else {
-        // Fallthrough, essentially UB.
-        value
-          .uint32_value(scope)
-          .expect("Unable to deserialize result parameter.") as u16
-      };
-      *(result as *mut u16) = value;
-    }
-    NativeType::U32 => {
-      let value = if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        value.value() as u32
-      } else {
-        // Fallthrough, essentially UB.
-        value
-          .uint32_value(scope)
-          .expect("Unable to deserialize result parameter.")
-      };
-      *(result as *mut u32) = value;
-    }
-    NativeType::I64 => {
-      if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
-        *(result as *mut i64) = value.i64_value().0;
-      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        *(result as *mut i64) = value.value();
-      } else {
-        *(result as *mut i64) = value
-          .integer_value(scope)
-          .expect("Unable to deserialize result parameter.")
-          as i64;
-      }
-    }
-    NativeType::U64 => {
-      if let Ok(value) = v8::Local::<v8::BigInt>::try_from(value) {
-        *(result as *mut u64) = value.u64_value().0;
-      } else if let Ok(value) = v8::Local::<v8::Integer>::try_from(value) {
-        *(result as *mut u64) = value.value() as u64;
-      } else {
-        *(result as *mut u64) = value
-          .integer_value(scope)
-          .expect("Unable to deserialize result parameter.")
-          as u64;
-      }
-    }
-    NativeType::Void => {
-      // nop
-    }
-    _ => {
-      unreachable!();
-    }
-  };
-}
-
-#[derive(Deserialize)]
-struct RegisterCallbackArgs {
-  parameters: Vec<NativeType>,
-  result: NativeType,
-}
-
-#[op(v8)]
-fn op_ffi_unsafe_callback_create<FP, 'scope>(
-  state: &mut deno_core::OpState,
-  scope: &mut v8::HandleScope<'scope>,
-  args: RegisterCallbackArgs,
-  cb: serde_v8::Value<'scope>,
-) -> Result<serde_v8::Value<'scope>, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafeCallback");
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let v8_value = cb.v8_value;
-  let cb = v8::Local::<v8::Function>::try_from(v8_value)?;
-
-  let isolate: *mut v8::Isolate = &mut *scope as &mut v8::Isolate;
-  LOCAL_ISOLATE_POINTER.with(|s| {
-    if s.borrow().is_null() {
-      s.replace(isolate);
-    }
-  });
-
-  let async_work_sender =
-    state.borrow_mut::<FfiState>().async_work_sender.clone();
-  let callback = v8::Global::new(scope, cb).into_raw();
-  let current_context = scope.get_current_context();
-  let context = v8::Global::new(scope, current_context).into_raw();
-
-  let info: *mut CallbackInfo = Box::leak(Box::new(CallbackInfo {
-    parameters: args.parameters.clone(),
-    result: args.result,
-    async_work_sender,
-    callback,
-    context,
-    isolate,
-    waker: None,
-  }));
-  let cif = Cif::new(
-    args.parameters.into_iter().map(libffi::middle::Type::from),
-    libffi::middle::Type::from(args.result),
-  );
-
-  // SAFETY: CallbackInfo is leaked, is not null and stays valid as long as the callback exists.
-  let closure = libffi::middle::Closure::new(cif, deno_ffi_callback, unsafe {
-    info.as_ref().unwrap()
-  });
-  let ptr = *closure.code_ptr() as usize;
-  let resource = UnsafeCallbackResource {
-    cancel: CancelHandle::new_rc(),
-    closure,
-    info,
-  };
-  let rid = state.resource_table.add(resource);
-
-  let rid_local = v8::Integer::new_from_unsigned(scope, rid);
-  let ptr_local: v8::Local<v8::Value> = if ptr > MAX_SAFE_INTEGER as usize {
-    v8::BigInt::new_from_u64(scope, ptr as u64).into()
-  } else {
-    v8::Number::new(scope, ptr as f64).into()
-  };
-  let array = v8::Array::new(scope, 2);
-  array.set_index(scope, 0, rid_local.into());
-  array.set_index(scope, 1, ptr_local);
-  let array_value: v8::Local<v8::Value> = array.into();
-
-  Ok(array_value.into())
-}
-
-#[op(v8)]
-fn op_ffi_call_ptr<FP, 'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: Rc<RefCell<deno_core::OpState>>,
-  pointer: usize,
-  def: ForeignFunction,
-  parameters: serde_v8::Value<'scope>,
-) -> Result<serde_v8::Value<'scope>, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable2(&state, "Deno.UnsafeFnPointer#call");
-  {
-    let mut state = state.borrow_mut();
-    let permissions = state.borrow_mut::<FP>();
-    permissions.check(None)?;
-  };
-
-  let symbol = PtrSymbol::new(pointer, &def);
-  let call_args = ffi_parse_args(scope, parameters, &def.parameters)?;
-
-  let result = ffi_call(
-    call_args,
-    &symbol.cif,
-    symbol.ptr,
-    &def.parameters,
-    def.result,
-  )?;
-  // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
-  let result = unsafe { result.to_v8(scope, def.result) };
-  Ok(result)
-}
-
-impl Future for CallbackInfo {
-  type Output = ();
-  fn poll(
-    mut self: Pin<&mut Self>,
-    cx: &mut std::task::Context<'_>,
-  ) -> std::task::Poll<Self::Output> {
-    // Always replace the waker to make sure it's bound to the proper Future.
-    self.waker.replace(cx.waker().clone());
-    // The future for the CallbackInfo never resolves: It can only be canceled.
-    Poll::Pending
-  }
-}
-
-#[op]
-fn op_ffi_unsafe_callback_ref(
-  state: Rc<RefCell<deno_core::OpState>>,
-  rid: ResourceId,
-) -> Result<impl Future<Output = Result<(), AnyError>>, AnyError> {
-  let state = state.borrow();
-  let callback_resource =
-    state.resource_table.get::<UnsafeCallbackResource>(rid)?;
-
-  Ok(async move {
-    let info: &mut CallbackInfo =
-    // SAFETY: CallbackInfo pointer stays valid as long as the resource is still alive.
-      unsafe { callback_resource.info.as_mut().unwrap() };
-    // Ignore cancellation rejection
-    let _ = info
-      .into_future()
-      .or_cancel(callback_resource.cancel.clone())
-      .await;
-    Ok(())
-  })
-}
-
-#[op(fast)]
-fn op_ffi_unsafe_callback_unref(
-  state: &mut deno_core::OpState,
-  rid: u32,
-) -> Result<(), AnyError> {
-  state
-    .resource_table
-    .get::<UnsafeCallbackResource>(rid)?
-    .cancel
-    .cancel();
-  Ok(())
-}
-
-#[op(v8)]
-fn op_ffi_call_ptr_nonblocking<'scope, FP>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: Rc<RefCell<deno_core::OpState>>,
-  pointer: usize,
-  def: ForeignFunction,
-  parameters: serde_v8::Value<'scope>,
-) -> Result<impl Future<Output = Result<Value, AnyError>>, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable2(&state, "Deno.UnsafeFnPointer#call");
-  {
-    let mut state = state.borrow_mut();
-    let permissions = state.borrow_mut::<FP>();
-    permissions.check(None)?;
-  };
-
-  let symbol = PtrSymbol::new(pointer, &def);
-  let call_args = ffi_parse_args(scope, parameters, &def.parameters)?;
-
-  let join_handle = tokio::task::spawn_blocking(move || {
-    let PtrSymbol { cif, ptr } = symbol.clone();
-    ffi_call(call_args, &cif, ptr, &def.parameters, def.result)
-  });
-
-  Ok(async move {
-    let result = join_handle
-      .await
-      .map_err(|err| anyhow!("Nonblocking FFI call failed: {}", err))??;
-    // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
-    Ok(unsafe { result.to_value(def.result) })
-  })
-}
-
-#[op(v8)]
-fn op_ffi_get_static<'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: &mut deno_core::OpState,
-  rid: ResourceId,
-  name: String,
-  static_type: NativeType,
-) -> Result<serde_v8::Value<'scope>, AnyError> {
-  let resource = state.resource_table.get::<DynamicLibraryResource>(rid)?;
-
-  let data_ptr = resource.get_static(name)?;
-
-  Ok(match static_type {
-    NativeType::Void => {
-      return Err(type_error("Invalid FFI static type 'void'"));
-    }
-    NativeType::Bool => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const bool) };
-      let boolean: v8::Local<v8::Value> =
-        v8::Boolean::new(scope, result).into();
-      boolean.into()
-    }
-    NativeType::U8 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const u8) };
-      let number: v8::Local<v8::Value> =
-        v8::Integer::new_from_unsigned(scope, result as u32).into();
-      number.into()
-    }
-    NativeType::I8 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const i8) };
-      let number: v8::Local<v8::Value> =
-        v8::Integer::new(scope, result as i32).into();
-      number.into()
-    }
-    NativeType::U16 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const u16) };
-      let number: v8::Local<v8::Value> =
-        v8::Integer::new_from_unsigned(scope, result as u32).into();
-      number.into()
-    }
-    NativeType::I16 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const i16) };
-      let number: v8::Local<v8::Value> =
-        v8::Integer::new(scope, result as i32).into();
-      number.into()
-    }
-    NativeType::U32 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const u32) };
-      let number: v8::Local<v8::Value> =
-        v8::Integer::new_from_unsigned(scope, result).into();
-      number.into()
-    }
-    NativeType::I32 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const i32) };
-      let number: v8::Local<v8::Value> = v8::Integer::new(scope, result).into();
-      number.into()
-    }
-    NativeType::U64 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const u64) };
-      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as u64 {
-        v8::BigInt::new_from_u64(scope, result).into()
-      } else {
-        v8::Number::new(scope, result as f64).into()
-      };
-      integer.into()
-    }
-    NativeType::I64 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const i64) };
-      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as i64
-        || result < MIN_SAFE_INTEGER as i64
-      {
-        v8::BigInt::new_from_i64(scope, result).into()
-      } else {
-        v8::Number::new(scope, result as f64).into()
-      };
-      integer.into()
-    }
-    NativeType::USize => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const usize) };
-      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as usize
-      {
-        v8::BigInt::new_from_u64(scope, result as u64).into()
-      } else {
-        v8::Number::new(scope, result as f64).into()
-      };
-      integer.into()
-    }
-    NativeType::ISize => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const isize) };
-      let integer: v8::Local<v8::Value> =
-        if !(MIN_SAFE_INTEGER..=MAX_SAFE_INTEGER).contains(&result) {
-          v8::BigInt::new_from_i64(scope, result as i64).into()
-        } else {
-          v8::Number::new(scope, result as f64).into()
-        };
-      integer.into()
-    }
-    NativeType::F32 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const f32) };
-      let number: v8::Local<v8::Value> =
-        v8::Number::new(scope, result as f64).into();
-      number.into()
-    }
-    NativeType::F64 => {
-      // SAFETY: ptr is user provided
-      let result = unsafe { ptr::read_unaligned(data_ptr as *const f64) };
-      let number: v8::Local<v8::Value> = v8::Number::new(scope, result).into();
-      number.into()
-    }
-    NativeType::Pointer | NativeType::Function | NativeType::Buffer => {
-      let result = data_ptr as u64;
-      let integer: v8::Local<v8::Value> = if result > MAX_SAFE_INTEGER as u64 {
-        v8::BigInt::new_from_u64(scope, result).into()
-      } else {
-        v8::Number::new(scope, result as f64).into()
-      };
-      integer.into()
-    }
-  })
-}
-
-/// A non-blocking FFI call.
-#[op(v8)]
-fn op_ffi_call_nonblocking<'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: Rc<RefCell<deno_core::OpState>>,
-  rid: ResourceId,
-  symbol: String,
-  parameters: serde_v8::Value<'scope>,
-) -> Result<impl Future<Output = Result<Value, AnyError>> + 'static, AnyError> {
-  let symbol = {
-    let state = state.borrow();
-    let resource = state.resource_table.get::<DynamicLibraryResource>(rid)?;
-    let symbols = &resource.symbols;
-    *symbols
-      .get(&symbol)
-      .ok_or_else(|| type_error("Invalid FFI symbol name"))?
-      .clone()
-  };
-
-  let call_args = ffi_parse_args(scope, parameters, &symbol.parameter_types)?;
-
-  let result_type = symbol.result_type;
-  let join_handle = tokio::task::spawn_blocking(move || {
-    let Symbol {
-      cif,
-      ptr,
-      parameter_types,
-      result_type,
-      ..
-    } = symbol.clone();
-    ffi_call(call_args, &cif, ptr, &parameter_types, result_type)
-  });
-
-  Ok(async move {
-    let result = join_handle
-      .await
-      .map_err(|err| anyhow!("Nonblocking FFI call failed: {}", err))??;
-    // SAFETY: Same return type declared to libffi; trust user to have it right beyond that.
-    Ok(unsafe { result.to_value(result_type) })
-  })
-}
-
-#[op(fast)]
-fn op_ffi_ptr_of<FP>(
-  state: &mut deno_core::OpState,
-  buf: *const u8,
-  out: &mut [u32],
-) -> Result<(), AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointer#of");
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let outptr = out.as_ptr() as *mut usize;
-  let length = out.len();
-  assert!(
-    length >= (std::mem::size_of::<usize>() / std::mem::size_of::<u32>())
-  );
-  assert_eq!(outptr as usize % std::mem::size_of::<usize>(), 0);
-
-  // SAFETY: Out buffer was asserted to be at least large enough to hold a usize, and properly aligned.
-  let out = unsafe { &mut *outptr };
-  *out = buf as usize;
-
-  Ok(())
-}
-
-unsafe extern "C" fn noop_deleter_callback(
-  _data: *mut c_void,
-  _byte_length: usize,
-  _deleter_data: *mut c_void,
-) {
-}
-
-#[op(v8)]
-fn op_ffi_get_buf<FP, 'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-  len: usize,
-) -> Result<serde_v8::Value<'scope>, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#arrayBuffer");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *mut c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid FFI pointer value, got nullptr"));
-  }
-
-  // SAFETY: Offset is user defined.
-  let ptr = unsafe { ptr.add(offset) };
-
-  // SAFETY: Trust the user to have provided a real pointer, and a valid matching size to it. Since this is a foreign pointer, we should not do any deletion.
-  let backing_store = unsafe {
-    v8::ArrayBuffer::new_backing_store_from_ptr(
-      ptr,
-      len,
-      noop_deleter_callback,
-      std::ptr::null_mut(),
-    )
-  }
-  .make_shared();
-  let array_buffer: v8::Local<v8::Value> =
-    v8::ArrayBuffer::with_backing_store(scope, &backing_store).into();
-  Ok(array_buffer.into())
-}
-
-#[op(fast)]
-fn op_ffi_buf_copy_into<FP>(
-  state: &mut deno_core::OpState,
-  src: usize,
-  offset: usize,
-  dst: &mut [u8],
-  len: usize,
-) -> Result<(), AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#copyInto");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  if dst.len() < len {
-    Err(range_error(
-      "Destination length is smaller than source length",
-    ))
-  } else {
-    let src = src as *const c_void;
-
-    // SAFETY: Offset is user defined.
-    let src = unsafe { src.add(offset) as *const u8 };
-
-    // SAFETY: src is user defined.
-    // dest is properly aligned and is valid for writes of len * size_of::<T>() bytes.
-    unsafe { ptr::copy::<u8>(src, dst.as_mut_ptr(), len) };
-    Ok(())
-  }
-}
-
-#[op(v8)]
-fn op_ffi_cstr_read<FP, 'scope>(
-  scope: &mut v8::HandleScope<'scope>,
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<serde_v8::Value<'scope>, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getCString");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid CString pointer, pointer is null"));
-  }
-
-  // SAFETY: Offset is user defined.
-  let ptr = unsafe { ptr.add(offset) };
-
-  // SAFETY: Pointer is user provided.
-  let cstr = unsafe { CStr::from_ptr(ptr as *const c_char) }
-    .to_str()
-    .map_err(|_| type_error("Invalid CString pointer, not valid UTF-8"))?;
-  let value: v8::Local<v8::Value> = v8::String::new(scope, cstr)
-    .ok_or_else(|| {
-      type_error("Invalid CString pointer, string exceeds max length")
-    })?
-    .into();
-  Ok(value.into())
-}
-
-#[op(fast)]
-fn op_ffi_read_bool<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<bool, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getBool");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid bool pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe { ptr::read_unaligned::<bool>(ptr.add(offset) as *const bool) })
-}
-
-#[op(fast)]
-fn op_ffi_read_u8<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<u32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getUint8");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid u8 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe { ptr::read_unaligned::<u8>(ptr.add(offset) as *const u8) as u32 })
-}
-
-#[op(fast)]
-fn op_ffi_read_i8<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<i32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getInt8");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid i8 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe { ptr::read_unaligned::<i8>(ptr.add(offset) as *const i8) as i32 })
-}
-
-#[op(fast)]
-fn op_ffi_read_u16<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<u32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getUint16");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid u16 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe {
-    ptr::read_unaligned::<u16>(ptr.add(offset) as *const u16) as u32
-  })
-}
-
-#[op(fast)]
-fn op_ffi_read_i16<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<i32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getInt16");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid i16 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe {
-    ptr::read_unaligned::<i16>(ptr.add(offset) as *const i16) as i32
-  })
-}
-
-#[op(fast)]
-fn op_ffi_read_u32<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<u32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getUint32");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid u32 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe {
-    ptr::read_unaligned::<u32>(ptr.add(offset) as *const u32) as u32
-  })
-}
-
-#[op(fast)]
-fn op_ffi_read_i32<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<i32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getInt32");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid i32 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe {
-    ptr::read_unaligned::<i32>(ptr.add(offset) as *const i32) as i32
-  })
-}
-
-#[op]
-fn op_ffi_read_u64<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-  out: &mut [u32],
-) -> Result<(), AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getBigUint64");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let outptr = out.as_mut_ptr() as *mut u64;
-
-  assert!(
-    out.len() >= (std::mem::size_of::<u64>() / std::mem::size_of::<u32>())
-  );
-  assert_eq!((outptr as usize % std::mem::size_of::<u64>()), 0);
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid u64 pointer, pointer is null"));
-  }
-
-  let value =
-  // SAFETY: ptr and offset are user provided.
-    unsafe { ptr::read_unaligned::<u64>(ptr.add(offset) as *const u64) };
-
-  // SAFETY: Length and alignment of out slice were asserted to be correct.
-  unsafe { *outptr = value };
-  Ok(())
-}
-
-#[op(fast)]
-fn op_ffi_read_i64<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-  out: &mut [u32],
-) -> Result<(), AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getBigUint64");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let outptr = out.as_mut_ptr() as *mut i64;
-
-  assert!(
-    out.len() >= (std::mem::size_of::<i64>() / std::mem::size_of::<u32>())
-  );
-  assert_eq!((outptr as usize % std::mem::size_of::<i64>()), 0);
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid i64 pointer, pointer is null"));
-  }
-
-  let value =
-  // SAFETY: ptr and offset are user provided.
-    unsafe { ptr::read_unaligned::<i64>(ptr.add(offset) as *const i64) };
-  // SAFETY: Length and alignment of out slice were asserted to be correct.
-  unsafe { *outptr = value };
-  Ok(())
-}
-
-#[op(fast)]
-fn op_ffi_read_f32<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<f32, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getFloat32");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid f32 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe { ptr::read_unaligned::<f32>(ptr.add(offset) as *const f32) })
-}
-
-#[op(fast)]
-fn op_ffi_read_f64<FP>(
-  state: &mut deno_core::OpState,
-  ptr: usize,
-  offset: usize,
-) -> Result<f64, AnyError>
-where
-  FP: FfiPermissions + 'static,
-{
-  check_unstable(state, "Deno.UnsafePointerView#getFloat64");
-
-  let permissions = state.borrow_mut::<FP>();
-  permissions.check(None)?;
-
-  let ptr = ptr as *const c_void;
-
-  if ptr.is_null() {
-    return Err(type_error("Invalid f64 pointer, pointer is null"));
-  }
-
-  // SAFETY: ptr and offset are user provided.
-  Ok(unsafe { ptr::read_unaligned::<f64>(ptr.add(offset) as *const f64) })
-}
-
-#[cfg(test)]
-mod tests {
-  #[cfg(target_os = "windows")]
-  #[test]
-  fn test_format_error() {
-    use super::format_error;
-
-    // BAD_EXE_FORMAT
-    let err = dlopen::Error::OpeningLibraryError(
-      std::io::Error::from_raw_os_error(0x000000C1),
-    );
-    assert_eq!(
-      format_error(err, "foo.dll".to_string()),
-      "foo.dll is not a valid Win32 application.\r\n".to_string(),
-    );
-  }
-}