async_hooks: fix nested hooks mutation

In some cases restoreTmpHooks is called too early, this causes
active_hooks_array to change during execution of the init hooks.

PR-URL: https://github.com/nodejs/node/pull/14143
Ref: https://github.com/nodejs/node/pull/14054#issuecomment-313915193
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Trevor Norris <trev.norris@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
This commit is contained in:
Andreas Madsen 2017-07-09 13:50:59 +02:00
parent 8a830350b2
commit f94fd0c0f3
No known key found for this signature in database
GPG Key ID: 2FEE61B3C9E40F20
3 changed files with 65 additions and 12 deletions

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@ -26,10 +26,10 @@ const { pushAsyncIds, popAsyncIds } = async_wrap;
// Using var instead of (preferably const) in order to assign
// tmp_active_hooks_array if a hook is enabled/disabled during hook execution.
var active_hooks_array = [];
// Track whether a hook callback is currently being processed. Used to make
// sure active_hooks_array isn't altered in mid execution if another hook is
// added or removed.
var processing_hook = false;
// Use a counter to track whether a hook callback is currently being processed.
// Used to make sure active_hooks_array isn't altered in mid execution if
// another hook is added or removed. A counter is used to track nested calls.
var processing_hook = 0;
// Use to temporarily store and updated active_hooks_array if the user enables
// or disables a hook while hooks are being processed.
var tmp_active_hooks_array = null;
@ -151,7 +151,7 @@ class AsyncHook {
function getHookArrays() {
if (!processing_hook)
if (processing_hook === 0)
return [active_hooks_array, async_hook_fields];
// If this hook is being enabled while in the middle of processing the array
// of currently active hooks then duplicate the current set of active hooks
@ -342,7 +342,7 @@ function emitHookFactory(symbol, name) {
// before this is called.
// eslint-disable-next-line func-style
const fn = function(asyncId) {
processing_hook = true;
processing_hook += 1;
// Use a single try/catch for all hook to avoid setting up one per
// iteration.
try {
@ -353,10 +353,11 @@ function emitHookFactory(symbol, name) {
}
} catch (e) {
fatalError(e);
} finally {
processing_hook -= 1;
}
processing_hook = false;
if (tmp_active_hooks_array !== null) {
if (processing_hook === 0 && tmp_active_hooks_array !== null) {
restoreTmpHooks();
}
};
@ -422,7 +423,7 @@ function emitDestroyS(asyncId) {
// slim chance of the application remaining stable after handling one of these
// exceptions.
function init(asyncId, type, triggerAsyncId, resource) {
processing_hook = true;
processing_hook += 1;
// Use a single try/catch for all hook to avoid setting up one per iteration.
try {
for (var i = 0; i < active_hooks_array.length; i++) {
@ -435,11 +436,18 @@ function init(asyncId, type, triggerAsyncId, resource) {
}
} catch (e) {
fatalError(e);
} finally {
processing_hook -= 1;
}
processing_hook = false;
// Isn't null if hooks were added/removed while the hooks were running.
if (tmp_active_hooks_array !== null) {
// * `tmp_active_hooks_array` is null if no hooks were added/removed while
// the hooks were running. In that case no restoration is needed.
// * In the case where another hook was added/removed while the hooks were
// running and a handle was created causing the `init` hooks to fire again,
// then `restoreTmpHooks` should not be called for the nested `hooks`.
// Otherwise `active_hooks_array` can change during execution of the
// `hooks`.
if (processing_hook === 0 && tmp_active_hooks_array !== null) {
restoreTmpHooks();
}
}

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@ -0,0 +1,23 @@
'use strict';
const common = require('../common');
const async_hooks = require('async_hooks');
const fs = require('fs');
let nestedCall = false;
async_hooks.createHook({
init: common.mustCall(function(id, type) {
nestedHook.disable();
if (!nestedCall) {
nestedCall = true;
fs.access(__filename, common.mustCall());
}
}, 2)
}).enable();
const nestedHook = async_hooks.createHook({
init: common.mustCall(2)
}).enable();
fs.access(__filename, common.mustCall());

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@ -0,0 +1,22 @@
'use strict';
const common = require('../common');
const async_hooks = require('async_hooks');
const fs = require('fs');
const nestedHook = async_hooks.createHook({
init: common.mustNotCall()
});
let nestedCall = false;
async_hooks.createHook({
init: common.mustCall(function(id, type) {
nestedHook.enable();
if (!nestedCall) {
nestedCall = true;
fs.access(__filename, common.mustCall());
}
}, 2)
}).enable();
fs.access(__filename, common.mustCall());