'use strict';
Object.defineProperty(exports, '__esModule', {
value: true
});
exports.default = exports.SIGKILL_DELAY = void 0;
function _child_process() {
const data = require('child_process');
_child_process = function () {
return data;
};
return data;
}
function _os() {
const data = require('os');
_os = function () {
return data;
};
return data;
}
function _mergeStream() {
const data = _interopRequireDefault(require('merge-stream'));
_mergeStream = function () {
return data;
};
return data;
}
function _supportsColor() {
const data = require('supports-color');
_supportsColor = function () {
return data;
};
return data;
}
var _types = require('../types');
var _WorkerAbstract = _interopRequireDefault(require('./WorkerAbstract'));
function _interopRequireDefault(obj) {
return obj && obj.__esModule ? obj : {default: obj};
}
/**
* Copyright (c) Meta Platforms, Inc. and affiliates.
*
* This source code is licensed under the MIT license found in the
* LICENSE file in the root directory of this source tree.
*/
const SIGNAL_BASE_EXIT_CODE = 128;
const SIGKILL_EXIT_CODE = SIGNAL_BASE_EXIT_CODE + 9;
const SIGTERM_EXIT_CODE = SIGNAL_BASE_EXIT_CODE + 15;
// How long to wait after SIGTERM before sending SIGKILL
const SIGKILL_DELAY = 500;
/**
* This class wraps the child process and provides a nice interface to
* communicate with. It takes care of:
*
* - Re-spawning the process if it dies.
* - Queues calls while the worker is busy.
* - Re-sends the requests if the worker blew up.
*
* The reason for queueing them here (since childProcess.send also has an
* internal queue) is because the worker could be doing asynchronous work, and
* this would lead to the child process to read its receiving buffer and start a
* second call. By queueing calls here, we don't send the next call to the
* children until we receive the result of the previous one.
*
* As soon as a request starts to be processed by a worker, its "processed"
* field is changed to "true", so that other workers which might encounter the
* same call skip it.
*/
exports.SIGKILL_DELAY = SIGKILL_DELAY;
class ChildProcessWorker extends _WorkerAbstract.default {
_child;
_options;
_request;
_retries;
_onProcessEnd;
_onCustomMessage;
_stdout;
_stderr;
_stderrBuffer = [];
_memoryUsagePromise;
_resolveMemoryUsage;
_childIdleMemoryUsage;
_childIdleMemoryUsageLimit;
_memoryUsageCheck = false;
_childWorkerPath;
constructor(options) {
super(options);
this._options = options;
this._request = null;
this._stdout = null;
this._stderr = null;
this._childIdleMemoryUsage = null;
this._childIdleMemoryUsageLimit = options.idleMemoryLimit || null;
this._childWorkerPath =
options.childWorkerPath || require.resolve('./processChild');
this.state = _types.WorkerStates.STARTING;
this.initialize();
}
initialize() {
if (
this.state === _types.WorkerStates.OUT_OF_MEMORY ||
this.state === _types.WorkerStates.SHUTTING_DOWN ||
this.state === _types.WorkerStates.SHUT_DOWN
) {
return;
}
if (this._child && this._child.connected) {
this._child.kill('SIGKILL');
}
this.state = _types.WorkerStates.STARTING;
const forceColor = _supportsColor().stdout
? {
FORCE_COLOR: '1'
}
: {};
const silent = this._options.silent ?? true;
if (!silent) {
// NOTE: Detecting an out of memory crash is independent of idle memory usage monitoring. We want to
// monitor for a crash occurring so that it can be handled as required and so we can tell the difference
// between an OOM crash and another kind of crash. We need to do this because if a worker crashes due to
// an OOM event sometimes it isn't seen by the worker pool and it just sits there waiting for the worker
// to respond and it never will.
console.warn('Unable to detect out of memory event if silent === false');
}
this._stderrBuffer = [];
const options = {
cwd: process.cwd(),
env: {
...process.env,
JEST_WORKER_ID: String(this._options.workerId + 1),
// 0-indexed workerId, 1-indexed JEST_WORKER_ID
...forceColor
},
// Suppress --debug / --inspect flags while preserving others (like --harmony).
execArgv: process.execArgv.filter(v => !/^--(debug|inspect)/.test(v)),
// default to advanced serialization in order to match worker threads
serialization: 'advanced',
silent,
...this._options.forkOptions
};
this._child = (0, _child_process().fork)(
this._childWorkerPath,
[],
options
);
if (this._child.stdout) {
if (!this._stdout) {
// We need to add a permanent stream to the merged stream to prevent it
// from ending when the subprocess stream ends
this._stdout = (0, _mergeStream().default)(this._getFakeStream());
}
this._stdout.add(this._child.stdout);
}
if (this._child.stderr) {
if (!this._stderr) {
// We need to add a permanent stream to the merged stream to prevent it
// from ending when the subprocess stream ends
this._stderr = (0, _mergeStream().default)(this._getFakeStream());
}
this._stderr.add(this._child.stderr);
this._child.stderr.on('data', this.stderrDataHandler.bind(this));
}
this._child.on('message', this._onMessage.bind(this));
this._child.on('exit', this._onExit.bind(this));
this._child.on('disconnect', this._onDisconnect.bind(this));
this._child.send([
_types.CHILD_MESSAGE_INITIALIZE,
false,
this._options.workerPath,
this._options.setupArgs
]);
this._retries++;
// If we exceeded the amount of retries, we will emulate an error reply
// coming from the child. This avoids code duplication related with cleaning
// the queue, and scheduling the next call.
if (this._retries > this._options.maxRetries) {
const error = new Error(
`Jest worker encountered ${this._retries} child process exceptions, exceeding retry limit`
);
this._onMessage([
_types.PARENT_MESSAGE_CLIENT_ERROR,
error.name,
error.message,
error.stack,
{
type: 'WorkerError'
}
]);
// Clear the request so we don't keep executing it.
this._request = null;
}
this.state = _types.WorkerStates.OK;
if (this._resolveWorkerReady) {
this._resolveWorkerReady();
}
}
stderrDataHandler(chunk) {
if (chunk) {
this._stderrBuffer.push(Buffer.from(chunk));
}
this._detectOutOfMemoryCrash();
if (this.state === _types.WorkerStates.OUT_OF_MEMORY) {
this._workerReadyPromise = undefined;
this._resolveWorkerReady = undefined;
this.killChild();
this._shutdown();
}
}
_detectOutOfMemoryCrash() {
try {
const bufferStr = Buffer.concat(this._stderrBuffer).toString('utf8');
if (
bufferStr.includes('heap out of memory') ||
bufferStr.includes('allocation failure;') ||
bufferStr.includes('Last few GCs')
) {
if (
this.state === _types.WorkerStates.OK ||
this.state === _types.WorkerStates.STARTING
) {
this.state = _types.WorkerStates.OUT_OF_MEMORY;
}
}
} catch (err) {
console.error('Error looking for out of memory crash', err);
}
}
_onDisconnect() {
this._workerReadyPromise = undefined;
this._resolveWorkerReady = undefined;
this._detectOutOfMemoryCrash();
if (this.state === _types.WorkerStates.OUT_OF_MEMORY) {
this.killChild();
this._shutdown();
}
}
_onMessage(response) {
// Ignore messages not intended for us
if (!Array.isArray(response)) return;
// TODO: Add appropriate type check
let error;
switch (response[0]) {
case _types.PARENT_MESSAGE_OK:
this._onProcessEnd(null, response[1]);
break;
case _types.PARENT_MESSAGE_CLIENT_ERROR:
error = response[4];
if (error != null && typeof error === 'object') {
const extra = error;
// @ts-expect-error: no index
const NativeCtor = globalThis[response[1]];
const Ctor = typeof NativeCtor === 'function' ? NativeCtor : Error;
error = new Ctor(response[2]);
error.type = response[1];
error.stack = response[3];
for (const key in extra) {
error[key] = extra[key];
}
}
this._onProcessEnd(error, null);
break;
case _types.PARENT_MESSAGE_SETUP_ERROR:
error = new Error(`Error when calling setup: ${response[2]}`);
error.type = response[1];
error.stack = response[3];
this._onProcessEnd(error, null);
break;
case _types.PARENT_MESSAGE_CUSTOM:
this._onCustomMessage(response[1]);
break;
case _types.PARENT_MESSAGE_MEM_USAGE:
this._childIdleMemoryUsage = response[1];
if (this._resolveMemoryUsage) {
this._resolveMemoryUsage(response[1]);
this._resolveMemoryUsage = undefined;
this._memoryUsagePromise = undefined;
}
this._performRestartIfRequired();
break;
default:
// Ignore messages not intended for us
break;
}
}
_performRestartIfRequired() {
if (this._memoryUsageCheck) {
this._memoryUsageCheck = false;
let limit = this._childIdleMemoryUsageLimit;
// TODO: At some point it would make sense to make use of
// stringToBytes found in jest-config, however as this
// package does not have any dependencies on an other jest
// packages that can wait until some other time.
if (limit && limit > 0 && limit <= 1) {
limit = Math.floor((0, _os().totalmem)() * limit);
} else if (limit) {
limit = Math.floor(limit);
}
if (
limit &&
this._childIdleMemoryUsage &&
this._childIdleMemoryUsage > limit
) {
this.state = _types.WorkerStates.RESTARTING;
this.killChild();
}
}
}
_onExit(exitCode, signal) {
this._workerReadyPromise = undefined;
this._resolveWorkerReady = undefined;
this._detectOutOfMemoryCrash();
if (exitCode !== 0 && this.state === _types.WorkerStates.OUT_OF_MEMORY) {
this._onProcessEnd(
new Error('Jest worker ran out of memory and crashed'),
null
);
this._shutdown();
} else if (
(exitCode !== 0 &&
exitCode !== null &&
exitCode !== SIGTERM_EXIT_CODE &&
exitCode !== SIGKILL_EXIT_CODE &&
this.state !== _types.WorkerStates.SHUTTING_DOWN) ||
this.state === _types.WorkerStates.RESTARTING
) {
this.state = _types.WorkerStates.RESTARTING;
this.initialize();
if (this._request) {
this._child.send(this._request);
}
} else {
// At this point, it's not clear why the child process exited. There could
// be several reasons:
//
// 1. The child process exited successfully after finishing its work.
// This is the most likely case.
// 2. The child process crashed in a manner that wasn't caught through
// any of the heuristic-based checks above.
// 3. The child process was killed by another process or daemon unrelated
// to Jest. For example, oom-killer on Linux may have picked the child
// process to kill because overall system memory is constrained.
//
// If there's a pending request to the child process in any of those
// situations, the request still needs to be handled in some manner before
// entering the shutdown phase. Otherwise the caller expecting a response
// from the worker will never receive indication that something unexpected
// happened and hang forever.
//
// In normal operation, the request is handled and cleared before the
// child process exits. If it's still present, it's not clear what
// happened and probably best to throw an error. In practice, this usually
// happens when the child process is killed externally.
//
// There's a reasonable argument that the child process should be retried
// with request re-sent in this scenario. However, if the problem was due
// to situations such as oom-killer attempting to free up system
// resources, retrying would exacerbate the problem.
const isRequestStillPending = !!this._request;
if (isRequestStillPending) {
// If a signal is present, we can be reasonably confident the process
// was killed externally. Log this fact so it's more clear to users that
// something went wrong externally, rather than a bug in Jest itself.
const error = new Error(
signal != null
? `A jest worker process (pid=${this._child.pid}) was terminated by another process: signal=${signal}, exitCode=${exitCode}. Operating system logs may contain more information on why this occurred.`
: `A jest worker process (pid=${this._child.pid}) crashed for an unknown reason: exitCode=${exitCode}`
);
this._onProcessEnd(error, null);
}
this._shutdown();
}
}
send(request, onProcessStart, onProcessEnd, onCustomMessage) {
this._stderrBuffer = [];
onProcessStart(this);
this._onProcessEnd = (...args) => {
const hasRequest = !!this._request;
// Clean the request to avoid sending past requests to workers that fail
// while waiting for a new request (timers, unhandled rejections...)
this._request = null;
if (
this._childIdleMemoryUsageLimit &&
this._child.connected &&
hasRequest
) {
this.checkMemoryUsage();
}
return onProcessEnd(...args);
};
this._onCustomMessage = (...arg) => onCustomMessage(...arg);
this._request = request;
this._retries = 0;
// eslint-disable-next-line @typescript-eslint/no-empty-function
this._child.send(request, () => {});
}
waitForExit() {
return this._exitPromise;
}
killChild() {
// We store a reference so that there's no way we can accidentally
// kill a new worker that has been spawned.
const childToKill = this._child;
childToKill.kill('SIGTERM');
return setTimeout(() => childToKill.kill('SIGKILL'), SIGKILL_DELAY);
}
forceExit() {
this.state = _types.WorkerStates.SHUTTING_DOWN;
const sigkillTimeout = this.killChild();
this._exitPromise.then(() => clearTimeout(sigkillTimeout));
}
getWorkerId() {
return this._options.workerId;
}
/**
* Gets the process id of the worker.
*
* @returns Process id.
*/
getWorkerSystemId() {
return this._child.pid;
}
getStdout() {
return this._stdout;
}
getStderr() {
return this._stderr;
}
/**
* Gets the last reported memory usage.
*
* @returns Memory usage in bytes.
*/
getMemoryUsage() {
if (!this._memoryUsagePromise) {
let rejectCallback;
const promise = new Promise((resolve, reject) => {
this._resolveMemoryUsage = resolve;
rejectCallback = reject;
});
this._memoryUsagePromise = promise;
if (!this._child.connected && rejectCallback) {
rejectCallback(new Error('Child process is not running.'));
this._memoryUsagePromise = undefined;
this._resolveMemoryUsage = undefined;
return promise;
}
this._child.send([_types.CHILD_MESSAGE_MEM_USAGE], err => {
if (err && rejectCallback) {
this._memoryUsagePromise = undefined;
this._resolveMemoryUsage = undefined;
rejectCallback(err);
}
});
return promise;
}
return this._memoryUsagePromise;
}
/**
* Gets updated memory usage and restarts if required
*/
checkMemoryUsage() {
if (this._childIdleMemoryUsageLimit) {
this._memoryUsageCheck = true;
this._child.send([_types.CHILD_MESSAGE_MEM_USAGE], err => {
if (err) {
console.error('Unable to check memory usage', err);
}
});
} else {
console.warn(
'Memory usage of workers can only be checked if a limit is set'
);
}
}
isWorkerRunning() {
return this._child.connected && !this._child.killed;
}
}
exports.default = ChildProcessWorker;