src/objects/js-generator.tq

// Copyright 2019 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Magic sentinel values for JSGeneratorObject.continuation.
const kGeneratorExecuting:
    constexpr int31 generates 'JSGeneratorObject::kGeneratorExecuting';
const kGeneratorClosed:
    constexpr int31 generates 'JSGeneratorObject::kGeneratorClosed';
const kGeneratorResumeModeNext:
    constexpr int31 generates 'JSGeneratorObject::kNext';
const kGeneratorResumeModeThrow:
    constexpr int31 generates 'JSGeneratorObject::kThrow';

@cppObjectLayoutDefinition
extern class JSGeneratorObject extends JSObject {
  function: JSFunction;
  context: Context;
  receiver: JSAny;

  // For executing generators: the most recent input value.
  // For suspended generators: debug information (bytecode offset).
  // There is currently no need to remember the most recent input value for a
  // suspended generator.
  input_or_debug_pos: Object;

  // The most recent resume mode.
  resume_mode: Smi;

  // A positive value indicates a suspended generator.  The special
  // kGeneratorExecuting and kGeneratorClosed values indicate that a generator
  // cannot be resumed.
  continuation: Smi;

  // Saved interpreter register file.
  parameters_and_registers: FixedArray;

  yielded_value: JSAny;
}

@cppObjectLayoutDefinition
extern class JSAsyncFunctionObject extends JSGeneratorObject {
  promise: JSPromise;
  // Resolve/reject closures for await, reused across all await expressions.
  // Initialized to undefined, lazily allocated on first await.
  await_resolve_closure: JSFunction|Undefined;
  await_reject_closure: JSFunction|Undefined;
}

@cppObjectLayoutDefinition
extern class JSAsyncGeneratorObject extends JSGeneratorObject {
  // Pointer to the head of a singly linked list of AsyncGeneratorRequest, or
  // undefined.
  queue: HeapObject;
  // Whether or not the generator is currently awaiting.
  is_awaiting: Smi;
}

@cppObjectLayoutDefinition
extern class AsyncGeneratorRequest extends Struct {
  next: AsyncGeneratorRequest|Undefined;
  resume_mode: Smi;
  value: Object;
  promise: JSPromise;
}