nstdlib-nightly/lib/internal/inspector_async_hook.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/inspector_async_hook.js

import * as __hoisted_async_hooks__ from "nstdlib/lib/async_hooks";

let hook;
let config;

function lazyHookCreation() {
  const inspector = require("binding/inspector");
  const { createHook } = __hoisted_async_hooks__;
  config = require("binding/config");

  hook = createHook({
    init(asyncId, type, triggerAsyncId, resource) {
      // It's difficult to tell which tasks will be recurring and which won't,
      // therefore we mark all tasks as recurring. Based on the discussion
      // in https://github.com/nodejs/node/pull/13870#discussion_r124515293,
      // this should be fine as long as we call asyncTaskCanceled() too.
      const recurring = true;
      if (type === "PROMISE") this.promiseIds.add(asyncId);
      else inspector.asyncTaskScheduled(type, asyncId, recurring);
    },

    before(asyncId) {
      if (this.promiseIds.has(asyncId)) return;
      inspector.asyncTaskStarted(asyncId);
    },

    after(asyncId) {
      if (this.promiseIds.has(asyncId)) return;
      inspector.asyncTaskFinished(asyncId);
    },

    destroy(asyncId) {
      if (this.promiseIds.has(asyncId)) return this.promiseIds.delete(asyncId);
      inspector.asyncTaskCanceled(asyncId);
    },
  });

  hook.promiseIds = new Set();
}

function enable() {
  if (hook === undefined) lazyHookCreation();
  if (config.bits < 64) {
    // V8 Inspector stores task ids as (void*) pointers.
    // async_hooks store ids as 64bit numbers.
    // As a result, we cannot reliably translate async_hook ids to V8 async_task
    // ids on 32bit platforms.
    process.emitWarning(
      "Warning: Async stack traces in debugger are not available " +
        `on ${config.bits}bit platforms. The feature is disabled.`,
      {
        code: "INSPECTOR_ASYNC_STACK_TRACES_NOT_AVAILABLE",
      },
    );
  } else {
    hook.enable();
  }
}

function disable() {
  if (hook === undefined) lazyHookCreation();
  hook.disable();
}

export { enable };
export { disable };