From 1facc67ab3bfd1f1a33ea16f00184e2ba3f26f9c Mon Sep 17 00:00:00 2001 From: Julien Gilli Date: Mon, 20 Apr 2015 18:43:23 -0700 Subject: [PATCH 1/3] timers: fix timeout when added in timer's callback When a timer is added in another timer's callback, its underlying timer handle will be started with a timeout that is actually incorrect. The reason is that the value that represents the current time is not updated between the time the original callback is called and the time the added timer is processed by timers.listOnTimeout. That leads the logic in timers.listOnTimeout to do an incorrect computation that makes the added timer fire with a timeout of scheduledTimeout + timeSpentInCallback. This change fixes that and make timers scheduled within other timers' callbacks fire as expected. Fixes: https://github.com/joyent/node/issues/9333 Fixes: https://github.com/joyent/node/issues/15447 PR: https://github.com/joyent/node/pull/17203 PR-URL: https://github.com/joyent/node/pull/17203 Reviewed-By: Fedor Indutny Conflicts: lib/timers.js test/common.js --- lib/timers.js | 13 ++- test/common.js | 6 +- .../parallel/test-timers-blocking-callback.js | 99 +++++++++++++++++++ 3 files changed, 115 insertions(+), 3 deletions(-) create mode 100644 test/parallel/test-timers-blocking-callback.js diff --git a/lib/timers.js b/lib/timers.js index 494c599b3cdfa1..9a860fcfcfbead 100644 --- a/lib/timers.js +++ b/lib/timers.js @@ -57,11 +57,20 @@ function listOnTimeout() { debug('timeout callback %d', msecs); var now = Timer.now(); - debug('now: %s', now); + debug('now: %d', now); var diff, first, threw; while (first = L.peek(list)) { - diff = now - first._idleStart; + // If the previous iteration caused a timer to be added, + // update the value of "now" so that timing computations are + // done correctly. See test/parallel/test-timers-blocking-callback.js + // for more information. + if (now < first._idleStart) { + now = Timer.now(); + debug('now: %d', now); + } + + diff = now - first._idleSTart; if (diff < msecs) { list.start(msecs - diff, 0); debug('%d list wait because diff is %d', msecs, diff); diff --git a/test/common.js b/test/common.js index 1a56449917be9c..993fe997146b84 100644 --- a/test/common.js +++ b/test/common.js @@ -451,5 +451,9 @@ exports.fileExists = function(pathname) { return true; } catch (err) { return false; - } + +exports.busyLoop = function busyLoop(time) { + var startTime = new Date().getTime(); + var stopTime = startTime + time; + while (new Date().getTime() < stopTime); }; diff --git a/test/parallel/test-timers-blocking-callback.js b/test/parallel/test-timers-blocking-callback.js new file mode 100644 index 00000000000000..c4a6dedb229ab6 --- /dev/null +++ b/test/parallel/test-timers-blocking-callback.js @@ -0,0 +1,99 @@ +// Copyright Joyent, Inc. and other Node contributors. +// +// Permission is hereby granted, free of charge, to any person obtaining a +// copy of this software and associated documentation files (the +// "Software"), to deal in the Software without restriction, including +// without limitation the rights to use, copy, modify, merge, publish, +// distribute, sublicense, and/or sell copies of the Software, and to permit +// persons to whom the Software is furnished to do so, subject to the +// following conditions: +// +// The above copyright notice and this permission notice shall be included +// in all copies or substantial portions of the Software. +// +// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS +// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN +// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, +// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR +// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE +// USE OR OTHER DEALINGS IN THE SOFTWARE. + +/* + * This is a regression test for https://github.com/joyent/node/issues/15447 + * and https://github.com/joyent/node/issues/9333. + * + * When a timer is added in another timer's callback, its underlying timer + * handle was started with a timeout that was actually incorrect. + * + * The reason was that the value that represents the current time was not + * updated between the time the original callback was called and the time + * the added timer was processed by timers.listOnTimeout. That lead the + * logic in timers.listOnTimeout to do an incorrect computation that made + * the added timer fire with a timeout of scheduledTimeout + + * timeSpentInCallback. + * + * This test makes sure that a timer added by another timer's callback + * fire with the expected timeout. + * + * It makes sure that it works when the timers list for a given timeout is + * empty (see testAddingTimerToEmptyTimersList) and when the timers list + * is not empty (see testAddingTimerToNonEmptyTimersList). + */ + +var assert = require('assert'); +var common = require('../common'); + +var TIMEOUT = 100; + +var nbBlockingCallbackCalls = 0; +var latestDelay = 0; +var timeCallbackScheduled = 0; + +function initTest() { + nbBlockingCallbackCalls = 0; + latestDelay = 0; + timeCallbackScheduled = 0; +} + +function blockingCallback(callback) { + ++nbBlockingCallbackCalls; + + if (nbBlockingCallbackCalls > 1) { + latestDelay = new Date().getTime() - timeCallbackScheduled; + // Even if timers can fire later than when they've been scheduled + // to fire, they should more than 50% later with a timeout of + // 100ms. Firing later than that would mean that we hit the regression + // highlighted in + // https://github.com/joyent/node/issues/15447 and + // https://github.com/joyent/node/issues/9333. + assert(latestDelay < TIMEOUT * 1.5); + if (callback) + return callback(); + } else { + // block by busy-looping to trigger the issue + common.busyLoop(TIMEOUT); + + timeCallbackScheduled = new Date().getTime(); + setTimeout(blockingCallback, TIMEOUT); + } +} + +function testAddingTimerToEmptyTimersList(callback) { + initTest(); + // Call setTimeout just once to make sure the timers list is + // empty when blockingCallback is called. + setTimeout(blockingCallback.bind(global, callback), TIMEOUT); +} + +function testAddingTimerToNonEmptyTimersList() { + initTest(); + // Call setTimeout twice with the same timeout to make + // sure the timers list is not empty when blockingCallback is called. + setTimeout(blockingCallback, TIMEOUT); + setTimeout(blockingCallback, TIMEOUT); +} + +// Run the test for the empty timers list case, and then for the non-empty +// timers list one +testAddingTimerToEmptyTimersList(testAddingTimerToNonEmptyTimersList); From 6c0cb864b18f8a9a0c6450a5370e3dacae565af4 Mon Sep 17 00:00:00 2001 From: Jeremiah Senkpiel Date: Mon, 27 Jul 2015 09:35:47 -0700 Subject: [PATCH 2/3] !fixup nits --- lib/timers.js | 2 +- test/common.js | 2 ++ .../parallel/test-timers-blocking-callback.js | 27 +++---------------- 3 files changed, 6 insertions(+), 25 deletions(-) diff --git a/lib/timers.js b/lib/timers.js index 9a860fcfcfbead..4ae6cf4b8c7997 100644 --- a/lib/timers.js +++ b/lib/timers.js @@ -70,7 +70,7 @@ function listOnTimeout() { debug('now: %d', now); } - diff = now - first._idleSTart; + diff = now - first._idleStart; if (diff < msecs) { list.start(msecs - diff, 0); debug('%d list wait because diff is %d', msecs, diff); diff --git a/test/common.js b/test/common.js index 993fe997146b84..81f64e39da1a92 100644 --- a/test/common.js +++ b/test/common.js @@ -451,6 +451,8 @@ exports.fileExists = function(pathname) { return true; } catch (err) { return false; + } +}; exports.busyLoop = function busyLoop(time) { var startTime = new Date().getTime(); diff --git a/test/parallel/test-timers-blocking-callback.js b/test/parallel/test-timers-blocking-callback.js index c4a6dedb229ab6..584b250da6648f 100644 --- a/test/parallel/test-timers-blocking-callback.js +++ b/test/parallel/test-timers-blocking-callback.js @@ -1,24 +1,3 @@ -// Copyright Joyent, Inc. and other Node contributors. -// -// Permission is hereby granted, free of charge, to any person obtaining a -// copy of this software and associated documentation files (the -// "Software"), to deal in the Software without restriction, including -// without limitation the rights to use, copy, modify, merge, publish, -// distribute, sublicense, and/or sell copies of the Software, and to permit -// persons to whom the Software is furnished to do so, subject to the -// following conditions: -// -// The above copyright notice and this permission notice shall be included -// in all copies or substantial portions of the Software. -// -// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS -// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF -// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN -// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, -// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR -// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE -// USE OR OTHER DEALINGS IN THE SOFTWARE. - /* * This is a regression test for https://github.com/joyent/node/issues/15447 * and https://github.com/joyent/node/issues/9333. @@ -41,10 +20,10 @@ * is not empty (see testAddingTimerToNonEmptyTimersList). */ -var assert = require('assert'); -var common = require('../common'); +const assert = require('assert'); +const common = require('../common'); -var TIMEOUT = 100; +const TIMEOUT = 100; var nbBlockingCallbackCalls = 0; var latestDelay = 0; From dc7bcc076470a8cb7aaa259df88a5b852dc3c61f Mon Sep 17 00:00:00 2001 From: Jeremiah Senkpiel Date: Mon, 27 Jul 2015 20:54:33 -0700 Subject: [PATCH 3/3] !fixup address nits --- test/common.js | 4 ++-- test/parallel/test-timers-blocking-callback.js | 8 +++++--- 2 files changed, 7 insertions(+), 5 deletions(-) diff --git a/test/common.js b/test/common.js index 81f64e39da1a92..1ee3d29e79b280 100644 --- a/test/common.js +++ b/test/common.js @@ -455,7 +455,7 @@ exports.fileExists = function(pathname) { }; exports.busyLoop = function busyLoop(time) { - var startTime = new Date().getTime(); + var startTime = Date.now(); var stopTime = startTime + time; - while (new Date().getTime() < stopTime); + while (Date.now() < stopTime); }; diff --git a/test/parallel/test-timers-blocking-callback.js b/test/parallel/test-timers-blocking-callback.js index 584b250da6648f..72ce4b3bd3ebe8 100644 --- a/test/parallel/test-timers-blocking-callback.js +++ b/test/parallel/test-timers-blocking-callback.js @@ -1,3 +1,5 @@ +'use strict'; + /* * This is a regression test for https://github.com/joyent/node/issues/15447 * and https://github.com/joyent/node/issues/9333. @@ -39,7 +41,7 @@ function blockingCallback(callback) { ++nbBlockingCallbackCalls; if (nbBlockingCallbackCalls > 1) { - latestDelay = new Date().getTime() - timeCallbackScheduled; + latestDelay = Date.now() - timeCallbackScheduled; // Even if timers can fire later than when they've been scheduled // to fire, they should more than 50% later with a timeout of // 100ms. Firing later than that would mean that we hit the regression @@ -53,7 +55,7 @@ function blockingCallback(callback) { // block by busy-looping to trigger the issue common.busyLoop(TIMEOUT); - timeCallbackScheduled = new Date().getTime(); + timeCallbackScheduled = Date.now(); setTimeout(blockingCallback, TIMEOUT); } } @@ -62,7 +64,7 @@ function testAddingTimerToEmptyTimersList(callback) { initTest(); // Call setTimeout just once to make sure the timers list is // empty when blockingCallback is called. - setTimeout(blockingCallback.bind(global, callback), TIMEOUT); + setTimeout(blockingCallback.bind(null, callback), TIMEOUT); } function testAddingTimerToNonEmptyTimersList() {