lts/lib/internal/inspector_async_hook.js
'use strict';
let hook;
let config;
const {
Set,
} = primordials;
function lazyHookCreation() {
const inspector = internalBinding('inspector');
const { createHook } = require('async_hooks');
config = internalBinding('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();
}
module.exports = {
enable,
disable
};