child_process: add timeout and killSignal to spawn and fork

Add support for timeout and killSignal to spawn and fork.

Fixes: #27639

doc/api/child_process.md

@@ -351,6 +351,9 @@ controller.abort();
 <!-- YAML
 added: v0.5.0
 changes:
+ - version: REPLACEME
+ pr-url: https:/nodejs/node/pull/37256
+ description: killSignal and timeout was added.
  - version: v15.6.0
  pr-url: https:/nodejs/node/pull/36603
  description: AbortSignal support was added.
@@ -394,6 +397,10 @@ changes:
  * `uid` {number} Sets the user identity of the process (see setuid(2)).
  * `windowsVerbatimArguments` {boolean} No quoting or escaping of arguments is
  done on Windows. Ignored on Unix. **Default:** `false`.
+ * `timeout` {number} In milliseconds the maximum amount of time the process
+ is allowed to run. **Default:** `undefined`.
+ * `killSignal` {string|integer} The signal value to be used when the spawned
+ process will be killed by timeout or abort signal. **Default:** `'SIGTERM'`.
 * Returns: {ChildProcess}
 
 The `child_process.fork()` method is a special case of
@@ -431,6 +438,9 @@ The `signal` option works exactly the same way it does in
 <!-- YAML
 added: v0.1.90
 changes:
+ - version: REPLACEME
+ pr-url: https:/nodejs/node/pull/37256
+ description: killSignal and timeout were added.
  - version: v15.5.0
  pr-url: https:/nodejs/node/pull/36432
  description: AbortSignal support was added.
@@ -477,6 +487,10 @@ changes:
  * `windowsHide` {boolean} Hide the subprocess console window that would
  normally be created on Windows systems. **Default:** `false`.
  * `signal` {AbortSignal} allows aborting the execFile using an AbortSignal.
+ * `timeout` {number} In milliseconds the maximum amount of time the process
+ is allowed to run. **Default:** `undefined`.
+ * `killSignal` {string|integer} The signal value to be used when the spawned
+ process will be killed by timeout or abort signal. **Default:** `'SIGTERM'`.
 
 * Returns: {ChildProcess}
 

lib/child_process.js

@@ -141,7 +141,26 @@ function fork(modulePath /* , args, options */) {
  options.execPath = options.execPath || process.execPath;
  options.shell = false;
 
- return spawn(options.execPath, args, options);
+ validateTimeout(options.timeout);
+ if (options.killSignal) {
+ options.killSignal = sanitizeKillSignal(options.killSignal);
+ }
+ const child = spawn(options.execPath, args, options);
+
+ if (options.timeout > 0) {
+ let timeoutId = setTimeout(() => {
+ child.kill(options.killSignal);
+ timeoutId = null;
+ }, options.timeout);
+
+ child.once('close', () => {
+ if (timeoutId) {
+ clearTimeout(timeoutId);
+ timeoutId = null;
+ }
+ });
+ }
+ return child;
 }
 
 function _forkChild(fd, serializationMode) {
@@ -758,6 +777,12 @@ function spawnWithSignal(file, args, options) {
  const opts = options && typeof options === 'object' && ('signal' in options) ?
  { ...options, signal: undefined } :
  options;
+
+ // Validate the timeout, if present.
+ validateTimeout(options?.timeout);
+ if (options?.killSignal) {
+ options.killSignal = sanitizeKillSignal(options.killSignal);
+ }
  const child = spawn(file, args, opts);
 
  if (options && options.signal) {
@@ -777,6 +802,21 @@ function spawnWithSignal(file, args, options) {
  child.once('close', remove);
  }
  }
+
+ if (options?.timeout > 0) {
+ let timeoutId = setTimeout(() => {
+ child.kill(options.killSignal);
+ timeoutId = null;
+ }, options.timeout);
+
+ child.once('close', () => {
+ if (timeoutId) {
+ clearTimeout(timeoutId);
+ timeoutId = null;
+ }
+ });
+ }
+
  return child;
 }
 module.exports = {

test/parallel/test-child-process-fork-abort-signal.js

@@ -26,8 +26,23 @@ const { fork } = require('child_process');
  const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
  signal
  });
- cp.on('exit', mustCall());
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGTERM')));
+ cp.on('error', mustCall((err) => {
+ strictEqual(err.name, 'AbortError');
+ }));
+}
+
+{
+ // Test correct signal sent
+ const ac = new AbortController();
+ const { signal } = ac;
+ const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ signal,
+ killSignal: 'SIGKILL',
+ });
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGKILL')));
  cp.on('error', mustCall((err) => {
  strictEqual(err.name, 'AbortError');
  }));
+ process.nextTick(() => ac.abort());
 }

test/parallel/test-child-process-fork-timeout-kill-signal.js

@@ -0,0 +1,69 @@
+'use strict';
+
+const { mustCall } = require('../common');
+const { strictEqual, ok, throws } = require('assert');
+const fixtures = require('../common/fixtures');
+const { fork } = require('child_process');
+const { getEventListeners } = require('events');
+
+{
+ // Verify default signal + closes after at least 4 ms.
+ let closed = false;
+ setTimeout(() => ok(!closed), 4);
+ const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: 5,
+ });
+ cp.on('close', mustCall(() => closed = true));
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGTERM')));
+}
+
+{
+ // Verify correct signal + closes after at least 4 ms.
+ let closed = false;
+ setTimeout(() => ok(!closed), 4);
+ const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: 5,
+ killSignal: 'SIGKILL',
+ });
+ cp.on('close', mustCall(() => closed = true));
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGKILL')));
+}
+
+{
+ // Verify timeout verification
+ throws(() => fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: 'badValue',
+ }), /ERR_OUT_OF_RANGE/);
+
+ throws(() => fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: {},
+ }), /ERR_OUT_OF_RANGE/);
+}
+
+{
+ // Verify abort signal gets unregistered
+ const signal = new EventTarget();
+ signal.aborted = false;
+
+ const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: 6,
+ signal,
+ });
+ strictEqual(getEventListeners(signal, 'abort').length, 1);
+ cp.on('close', mustCall(() => {
+ strictEqual(getEventListeners(signal, 'abort').length, 0);
+ }));
+}
+
+{
+ // Verify no error happens when abort is called timeout
+ const controller = new AbortController();
+ const { signal } = controller;
+
+ const cp = fork(fixtures.path('child-process-stay-alive-forever.js'), {
+ timeout: 100,
+ signal,
+ });
+ cp.on('error', mustCall());
+ setTimeout(() => controller.abort(), 1);
+}

test/parallel/test-child-process-spawn-controller.js

@@ -39,3 +39,49 @@ const cp = require('child_process');
  assert.strictEqual(e.name, 'AbortError');
  }));
 }
+
+{
+ // Verify that passing kill signal works.
+ const controller = new AbortController();
+ const { signal } = controller;
+
+ const echo = cp.spawn('echo', ['fun'], {
+ encoding: 'utf8',
+ shell: true,
+ signal,
+ killSignal: 'SIGKILL',
+ });
+
+ echo.on('close', common.mustCall((code, killSignal) => {
+ assert.strictEqual(killSignal, 'SIGKILL');
+ }));
+
+ echo.on('error', common.mustCall((e) => {
+ assert.strictEqual(e.name, 'AbortError');
+ }));
+
+ controller.abort();
+}
+
+{
+ // Verify that passing a different kill signal works.
+ const controller = new AbortController();
+ const { signal } = controller;
+
+ const echo = cp.spawn('echo', ['fun'], {
+ encoding: 'utf8',
+ shell: true,
+ signal,
+ killSignal: 'SIGTERM',
+ });
+
+ echo.on('close', common.mustCall((code, killSignal) => {
+ assert.strictEqual(killSignal, 'SIGTERM');
+ }));
+
+ echo.on('error', common.mustCall((e) => {
+ assert.strictEqual(e.name, 'AbortError');
+ }));
+
+ controller.abort();
+}

test/parallel/test-child-process-spawn-timeout-kill-signal.js

@@ -0,0 +1,70 @@
+'use strict';
+
+const { mustCall } = require('../common');
+const { strictEqual, ok, throws } = require('assert');
+const fixtures = require('../common/fixtures');
+const { spawn } = require('child_process');
+const { getEventListeners } = require('events');
+
+const aliveForeverFile = 'child-process-stay-alive-forever.js';
+{
+ // Verify default signal + closes after at least 4 ms.
+ let closed = false;
+ setTimeout(() => ok(!closed), 4);
+ const cp = spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: 5,
+ });
+ cp.on('close', mustCall(() => closed = true));
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGTERM')));
+}
+
+{
+ // Verify correct signal + closes after at least 4 ms.
+ let closed = false;
+ setTimeout(() => ok(!closed), 4);
+ const cp = spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: 5,
+ killSignal: 'SIGKILL',
+ });
+ cp.on('close', mustCall(() => closed = true));
+ cp.on('exit', mustCall((code, ks) => strictEqual(ks, 'SIGKILL')));
+}
+
+{
+ // Verify timeout verification
+ throws(() => spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: 'badValue',
+ }), /ERR_OUT_OF_RANGE/);
+
+ throws(() => spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: {},
+ }), /ERR_OUT_OF_RANGE/);
+}
+
+{
+ // Verify abort signal gets unregistered
+ const signal = new EventTarget();
+ signal.aborted = false;
+
+ const cp = spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: 6,
+ signal,
+ });
+ strictEqual(getEventListeners(signal, 'abort').length, 1);
+ cp.on('close', mustCall(() => {
+ strictEqual(getEventListeners(signal, 'abort').length, 0);
+ }));
+}
+
+{
+ // Verify no error happens when abort is called timeout
+ const controller = new AbortController();
+ const { signal } = controller;
+
+ const cp = spawn(process.execPath, [fixtures.path(aliveForeverFile)], {
+ timeout: 100,
+ signal,
+ });
+ cp.on('error', mustCall());
+ setTimeout(() => controller.abort(), 1);
+}