Skip to content

Commit

Permalink
timers: fix not to close reused timer handle
Browse files Browse the repository at this point in the history
The timer handle is reused when it is unrefed in order to avoid new
callback in beforeExit(nodejs#3407). If it is unrefed within a setInterval
callback, the reused timer handle is closed so that setInterval no
longer keep working. This fix does not close the handle in case of
setInterval.

PR-URL: nodejs/node#11646
Reviewed-By: Julien Gilli <jgilli@nodejs.org>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
  • Loading branch information
shigeki authored and andrew749 committed Jul 19, 2017
1 parent f344ed8 commit 22bc5d9
Show file tree
Hide file tree
Showing 2 changed files with 68 additions and 1 deletion.
8 changes: 7 additions & 1 deletion lib/timers.js
Original file line number Diff line number Diff line change
Expand Up @@ -222,7 +222,6 @@ function listOnTimeout() {
// As such, we can remove the list and clean up the TimerWrap C++ handle.
debug('%d list empty', msecs);
assert(L.isEmpty(list));
this.close();

// Either refedLists[msecs] or unrefedLists[msecs] may have been removed and
// recreated since the reference to `list` was created. Make sure they're
Expand All @@ -232,6 +231,13 @@ function listOnTimeout() {
} else if (list === refedLists[msecs]) {
delete refedLists[msecs];
}

// Do not close the underlying handle if its ownership has changed
// (e.g it was unrefed in its callback).
if (this.owner)
return;

this.close();
}


Expand Down
61 changes: 61 additions & 0 deletions test/parallel/test-timers-unrefed-in-callback.js
Original file line number Diff line number Diff line change
@@ -0,0 +1,61 @@
'use strict';
// Checks that setInterval timers keep running even when they're
// unrefed within their callback.

require('../common');
const assert = require('assert');
const net = require('net');

let counter1 = 0;
let counter2 = 0;

// Test1 checks that clearInterval works as expected for a timer
// unrefed within its callback: it removes the timer and its callback
// is not called anymore. Note that the only reason why this test is
// robust is that:
// 1. the repeated timer it creates has a delay of 1ms
// 2. when this test is completed, another test starts that creates a
// new repeated timer with the same delay (1ms)
// 3. because of the way timers are implemented in libuv, if two
// repeated timers A and B are created in that order with the same
// delay, it is guaranteed that the first occurrence of timer A
// will fire before the first occurrence of timer B
// 4. as a result, when the timer created by Test2 fired 11 times, if
// the timer created by Test1 hadn't been removed by clearInterval,
// it would have fired 11 more times, and the assertion in the
// process'exit event handler would fail.
function Test1() {
// server only for maintaining event loop
const server = net.createServer().listen(0);

const timer1 = setInterval(() => {
timer1.unref();
if (counter1++ === 3) {
clearInterval(timer1);
server.close(() => {
Test2();
});
}
}, 1);
}


// Test2 checks setInterval continues even if it is unrefed within
// timer callback. counter2 continues to be incremented more than 11
// until server close completed.
function Test2() {
// server only for maintaining event loop
const server = net.createServer().listen(0);

const timer2 = setInterval(() => {
timer2.unref();
if (counter2++ === 3)
server.close();
}, 1);
}

process.on('exit', () => {
assert.strictEqual(counter1, 4);
});

Test1();

0 comments on commit 22bc5d9

Please sign in to comment.