Skip to main content

Browse the archive

https://github.com/web-platform-tests/wpt
26 December 2018, 22:31:15 UTC
Revision 4e5f09f89e6f1976dd49a57ba46cd447c7e19a1e authored by Alex Moshchuk on 13 April 2018, 15:22:14 UTC, committed by Chromium WPT Sync on 13 April 2018, 15:22:14 UTC 
Reland: Use PostTask to schedule cross-process postMessage forwarding.
 
Changes from original attempt at https://crrev.com/c/999182:
- fix flakiness in two additional ChromeOS login tests
- fix CSP WPT tests to not depend on ordering between iframe's onload
  and postMessage - see https://crbug.com/832319.

Previously, we sent the IPC to forward a cross-process postMessage
immediately.  This caused a behavioral difference from the
same-process case where the postMessage is always scheduled.  Namely,
in a scenario like this:

  frame.postMessage(...);
  doSomethingThatSendsIPCsToFrame(frame);

the IPCs from JS following the postMessage would've been ordered
incorrectly, causing |frame| to see their side effects after the
postMessage dispatch in the cross-process case, whereas they would be
seen before the postMessage dispatch in the same-process case.  One
example of this is frame.focus(), and another is a frame element
onload event (dispatched via FrameHostMsg_DispatchLoad) arriving after
a postMessage dispatched from an inline script while the frame was
still loading.

To resolve these ordering concerns, this CL changes cross-process
postMessage to do a PostTask on the sender side before sending the
message to the browser process.  This improves the current state of
the world, but does not yet achieve a perfect match for the IPC
ordering in the same-process case - see discussion on the bug.

Bug: 828529
Change-Id: I62a627c501526d09900be4f5bd2c899acf4d1e07
Reviewed-on: https://chromium-review.googlesource.com/999182
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Alex Moshchuk <alexmos@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#550284}
Reviewed-on: https://chromium-review.googlesource.com/1011287
Cr-Commit-Position: refs/heads/master@{#550621}
1 parent f90d3d6
Raw File
Tip revision: 4e5f09f89e6f1976dd49a57ba46cd447c7e19a1e authored by Alex Moshchuk on 13 April 2018, 15:22:14 UTC
Reland: Use PostTask to schedule cross-process postMessage forwarding.
Tip revision: 4e5f09f
same-document-zero-size-target.html 
<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="./resources/intersection-observer-test-utils.js"></script>

<style>
pre, #log {
  position: absolute;
  top: 0;
  left: 200px;
}
.spacer {
  height: calc(100vh + 100px);
}
#target {
  width: 0px;
  height: 0px;
  background-color: green;
}
</style>

<div class="spacer"></div>
<div id="target"></div>
<div class="spacer"></div>

<script>
var vw = document.documentElement.clientWidth;
var vh = document.documentElement.clientHeight;

var entries = [];
var target;

runTestCycle(function() {
  target = document.getElementById("target");
  assert_true(!!target, "Target exists");
  var observer = new IntersectionObserver(function(changes) {
    entries = entries.concat(changes)
  });
  observer.observe(target);
  entries = entries.concat(observer.takeRecords());
  assert_equals(entries.length, 0, "No initial notifications.");
  runTestCycle(step0, "First rAF");
}, "Observing a zero-area target.");

function step0() {
  document.scrollingElement.scrollTop = 300;
  runTestCycle(step1, "document.scrollingElement.scrollTop = 300");
  checkLastEntry(entries, 0, [8, 8, vh + 108, vh + 108, 0, 0, 0, 0, 0, vw, 0, vh, false]);
}

function step1() {
  document.scrollingElement.scrollTop = 100;
  runTestCycle(step2, "document.scrollingElement.scrollTop = 100");
  checkLastEntry(entries, 1, [8, 8, vh - 192, vh - 192, 8, 8, vh - 192, vh - 192, 0, vw, 0, vh, true]);
}

function step2() {
  document.scrollingElement.scrollTop = 0;
  checkLastEntry(entries, 2, [8, 8, vh + 8, vh + 8, 0, 0, 0, 0, 0, vw, 0, vh, false]);
}
</script>
back to top