1 files changed, 89 insertions, 3 deletions

diff --git a/core/bindings.rs b/core/bindings.rs
index 1a869f3c4..b50c77df2 100644
--- a/core/bindings.rs
+++ b/core/bindings.rs
@@ -97,6 +97,7 @@ pub fn initialize_context<'s>(
   scope: &mut v8::HandleScope<'s, ()>,
   op_ctxs: &[OpCtx],
   snapshot_loaded: bool,
+  will_snapshot: bool,
 ) -> v8::Local<'s, v8::Context> {
   let scope = &mut v8::EscapableHandleScope::new(scope);
 
@@ -112,7 +113,9 @@ pub fn initialize_context<'s>(
     let ops_obj = JsRuntime::grab_global::<v8::Object>(scope, "Deno.core.ops")
       .expect("Deno.core.ops to exist");
     initialize_ops(scope, ops_obj, op_ctxs, snapshot_loaded);
-
+    if !will_snapshot {
+      initialize_async_ops_info(scope, ops_obj, op_ctxs);
+    }
     return scope.escape(context);
   }
 
@@ -124,8 +127,10 @@ pub fn initialize_context<'s>(
 
   // Bind functions to Deno.core.ops.*
   let ops_obj = JsRuntime::ensure_objs(scope, global, "Deno.core.ops").unwrap();
-
-  initialize_ops(scope, ops_obj, op_ctxs, snapshot_loaded);
+  if !will_snapshot {
+    initialize_async_ops_info(scope, ops_obj, op_ctxs);
+  }
+  initialize_ops(scope, ops_obj, op_ctxs, !will_snapshot);
   scope.escape(context)
 }
 
@@ -586,3 +591,84 @@ pub fn throw_type_error(scope: &mut v8::HandleScope, message: impl AsRef<str>) {
   let exception = v8::Exception::type_error(scope, message);
   scope.throw_exception(exception);
 }
+
+struct AsyncOpsInfo {
+  ptr: *const OpCtx,
+  len: usize,
+}
+
+impl<'s> IntoIterator for &'s AsyncOpsInfo {
+  type Item = &'s OpCtx;
+  type IntoIter = AsyncOpsInfoIterator<'s>;
+
+  fn into_iter(self) -> Self::IntoIter {
+    AsyncOpsInfoIterator {
+      // SAFETY: OpCtx slice is valid for the lifetime of the Isolate
+      info: unsafe { std::slice::from_raw_parts(self.ptr, self.len) },
+      index: 0,
+    }
+  }
+}
+
+struct AsyncOpsInfoIterator<'s> {
+  info: &'s [OpCtx],
+  index: usize,
+}
+
+impl<'s> Iterator for AsyncOpsInfoIterator<'s> {
+  type Item = &'s OpCtx;
+
+  fn next(&mut self) -> Option<Self::Item> {
+    loop {
+      match self.info.get(self.index) {
+        Some(ctx) if ctx.decl.is_async => {
+          self.index += 1;
+          return Some(ctx);
+        }
+        Some(_) => {
+          self.index += 1;
+        }
+        None => return None,
+      }
+    }
+  }
+}
+
+fn async_ops_info(
+  scope: &mut v8::HandleScope,
+  args: v8::FunctionCallbackArguments,
+  mut rv: v8::ReturnValue,
+) {
+  let async_op_names = v8::Object::new(scope);
+  let external: v8::Local<v8::External> = args.data().try_into().unwrap();
+  let info: &AsyncOpsInfo =
+    // SAFETY: external is guaranteed to be a valid pointer to AsyncOpsInfo
+    unsafe { &*(external.value() as *const AsyncOpsInfo) };
+  for ctx in info {
+    let name = v8::String::new(scope, ctx.decl.name).unwrap();
+    let argc = v8::Integer::new(scope, ctx.decl.argc as i32);
+    async_op_names.set(scope, name.into(), argc.into());
+  }
+  rv.set(async_op_names.into());
+}
+
+fn initialize_async_ops_info(
+  scope: &mut v8::HandleScope,
+  ops_obj: v8::Local<v8::Object>,
+  op_ctxs: &[OpCtx],
+) {
+  let key = v8::String::new(scope, "asyncOpsInfo").unwrap();
+  let external = v8::External::new(
+    scope,
+    Box::into_raw(Box::new(AsyncOpsInfo {
+      ptr: op_ctxs as *const [OpCtx] as _,
+      len: op_ctxs.len(),
+    })) as *mut c_void,
+  );
+  let val = v8::Function::builder(async_ops_info)
+    .data(external.into())
+    .build(scope)
+    .unwrap();
+  val.set_name(key);
+  ops_obj.set(scope, key.into(), val.into());
+}