timers: fix refresh inside callback

When `timers.refresh()` is called inside a callback, the timer would incorrectly end up unrefed and thus not keep the event loop alive. PR-URL: #26721 Fixes: #26642 Reviewed-By: Ruben Bridgewater <[email protected]> Reviewed-By: Richard Lau <[email protected]> Reviewed-By: Weijia Wang <[email protected]> Reviewed-By: Anto Aravinth <[email protected]> Reviewed-By: Jeremiah Senkpiel <[email protected]>
nodejs · Mar 27, 2019 · 3ec652a · 3ec652a
1 parent 899de0a
commit 3ec652a
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diff --git a/lib/internal/timers.js b/lib/internal/timers.js
@@ -469,7 +469,7 @@ function getTimerCallbacks(runNextTicks) {
           if (start === undefined)
             start = getLibuvNow();
           insert(timer, timer[kRefed], start);
-        } else {
+        } else if (!timer._idleNext && !timer._idlePrev) {
           if (timer[kRefed])
             refCount--;
           timer[kRefed] = null;

diff --git a/test/parallel/test-timers-refresh-in-callback.js b/test/parallel/test-timers-refresh-in-callback.js
@@ -0,0 +1,14 @@
+'use strict';
+
+const common = require('../common');
+
+// This test checks whether a refresh called inside the callback will keep
+// the event loop alive to run the timer again.
+
+let didCall = false;
+const timer = setTimeout(common.mustCall(() => {
+  if (!didCall) {
+    didCall = true;
+    timer.refresh();
+  }
+}, 2), 1);