browser_BrowserUtils_idle_window_leak.js

Enable keyboard shortcuts

/* Any copyright is dedicated to the Public Domain.

   http://creativecommons.org/publicdomain/zero/1.0/ */

// A browser window's per-window idle tasks must not keep it alive after it

// closes when the idle queue is starved (bug 2082943).

add_task(async function test_closed_window_freed_with_pending_idle_tasks() {

  // Keep a normal priority task pending at all times so idle tasks can't run.

  let starve = true;

  let spin = () => {

    if (starve) {

      Services.tm.dispatchToMainThread(spin);

};

  registerCleanupFunction(() => (starve = false));

  let idleRan = false;

  ChromeUtils.idleDispatch(() => (idleRan = true));

  spin();

  let win = await BrowserTestUtils.openNewBrowserWindow();

  // The per-window idle tasks are queued once session restore is done.

  await BrowserTestUtils.waitForMutationCondition(

    win.document.documentElement,

    { attributeFilter: ["sessionrestored"] },

    () => win.document.documentElement.hasAttribute("sessionrestored")

);

  let weakWin = Cu.getWeakReference(win);

  await BrowserTestUtils.closeWindow(win);

  win = null;

  let freed = await TestUtils.waitForCondition(

    () => {

      // Shrinking, to also discard JIT code that can keep the closed window's

      // realm alive (bug 2041420).

      Cu.forceShrinkingGC();

      Cu.forceCC();

      return !weakWin.get();

},

    "Waiting for the closed window to be freed",

    100,

  ).then(

    () => true,

    () => false

);

  starve = false;

  Assert.ok(!idleRan, "Idle tasks were starved while the window was closed");

  Assert.ok(freed, "The closed window was freed despite pending idle tasks");

});