From 0c6597b3e013995a0893bcc0f2459bd874db740f Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@mit.edu>
Date: Thu, 7 May 2015 14:49:31 -0400
Subject: [PATCH] Bug 1162013.  Process the Promise queue between adjacent
 setTimeout callback invocations when we're going through the callback list
 without returning to the event loop.  r=smaug

---
 dom/base/nsGlobalWindow.cpp                   | 22 +++++++++++++------
 .../file_promise_and_timeout_ordering.js      | 18 +++++++++++++++
 dom/promise/tests/mochitest.ini               |  4 ++++
 .../test_promise_and_timeout_ordering.html    | 15 +++++++++++++
 ..._promise_and_timeout_ordering_workers.html | 13 +++++++++++
 dom/workers/WorkerPrivate.cpp                 |  4 ++++
 6 files changed, 69 insertions(+), 7 deletions(-)
 create mode 100644 dom/promise/tests/file_promise_and_timeout_ordering.js
 create mode 100644 dom/promise/tests/test_promise_and_timeout_ordering.html
 create mode 100644 dom/promise/tests/test_promise_and_timeout_ordering_workers.html

diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 19f1723aa5fc..cc82583b6e1f 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -12447,6 +12447,11 @@ nsGlobalWindow::RunTimeoutHandler(nsTimeout* aTimeout,
 
   mRunningTimeout = last_running_timeout;
   timeout->mRunning = false;
+
+  // Since we might be processing more timeouts, go ahead and flush the promise
+  // queue now before we do that.
+  Promise::PerformMicroTaskCheckpoint();
+
   return timeout->mCleared;
 }
 
@@ -12566,14 +12571,17 @@ nsGlobalWindow::RunTimeout(nsTimeout *aTimeout)
     deadline = now;
   }
 
-  // The timeout list is kept in deadline order. Discover the latest
-  // timeout whose deadline has expired. On some platforms, native
-  // timeout events fire "early", so we need to test the timer as well
-  // as the deadline.
+  // The timeout list is kept in deadline order. Discover the latest timeout
+  // whose deadline has expired. On some platforms, native timeout events fire
+  // "early", but we handled that above by setting deadline to aTimeout->mWhen
+  // if the timer fired early.  So we can stop walking if we get to timeouts
+  // whose mWhen is greater than deadline, since once that happens we know
+  // nothing past that point is expired.
   last_expired_timeout = nullptr;
-  for (nsTimeout *timeout = mTimeouts.getFirst(); timeout; timeout = timeout->getNext()) {
-    if (((timeout == aTimeout) || (timeout->mWhen <= deadline)) &&
-        (timeout->mFiringDepth == 0)) {
+  for (nsTimeout *timeout = mTimeouts.getFirst();
+       timeout && timeout->mWhen <= deadline;
+       timeout = timeout->getNext()) {
+    if (timeout->mFiringDepth == 0) {
       // Mark any timeouts that are on the list to be fired with the
       // firing depth so that we can reentrantly run timeouts
       timeout->mFiringDepth = firingDepth;
diff --git a/dom/promise/tests/file_promise_and_timeout_ordering.js b/dom/promise/tests/file_promise_and_timeout_ordering.js
new file mode 100644
index 000000000000..c83b5a6ac0b2
--- /dev/null
+++ b/dom/promise/tests/file_promise_and_timeout_ordering.js
@@ -0,0 +1,18 @@
+var log = [];
+var resolvedPromise = Promise.resolve(null);
+function schedulePromiseTask(f) {
+  resolvedPromise.then(f);
+}
+
+setTimeout(function() {
+  log.push('t1start');
+  schedulePromiseTask(function() {
+    log.push('promise');
+  });
+  log.push('t1end');
+}, 10);
+
+setTimeout(function() {
+  log.push('t2');
+  postMessage(log.join(', '));
+}, 10);
diff --git a/dom/promise/tests/mochitest.ini b/dom/promise/tests/mochitest.ini
index 3b621b1e1967..3dadb7240791 100644
--- a/dom/promise/tests/mochitest.ini
+++ b/dom/promise/tests/mochitest.ini
@@ -7,3 +7,7 @@
 [test_resolve.html]
 [test_resolver_return_value.html]
 [test_thenable_vs_promise_ordering.html]
+[test_promise_and_timeout_ordering.html]
+support-files = file_promise_and_timeout_ordering.js
+[test_promise_and_timeout_ordering_workers.html]
+support-files = file_promise_and_timeout_ordering.js
diff --git a/dom/promise/tests/test_promise_and_timeout_ordering.html b/dom/promise/tests/test_promise_and_timeout_ordering.html
new file mode 100644
index 000000000000..1dfa13bbba3e
--- /dev/null
+++ b/dom/promise/tests/test_promise_and_timeout_ordering.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for promise and timeout ordering</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var t = async_test("Promise callbacks should run immediately after the setTimeout handler that enqueues them");
+var origPostMessage = window.postMessage;
+window.postMessage = function(msg) { origPostMessage.call(window, msg, "*"); }
+window.onmessage = t.step_func_done(function(e) {
+  assert_equals(e.data, "t1start, t1end, promise, t2");
+});
+</script>
+<script src="file_promise_and_timeout_ordering.js"></script>
diff --git a/dom/promise/tests/test_promise_and_timeout_ordering_workers.html b/dom/promise/tests/test_promise_and_timeout_ordering_workers.html
new file mode 100644
index 000000000000..122a794db645
--- /dev/null
+++ b/dom/promise/tests/test_promise_and_timeout_ordering_workers.html
@@ -0,0 +1,13 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Test for promise and timeout ordering in workers</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<div id="log"></div>
+<script>
+var t = async_test("Promise callbacks in workers should run immediately after the setTimeout handler that enqueues them");
+var w = new Worker("file_promise_and_timeout_ordering.js");
+w.onmessage = t.step_func_done(function(e) {
+  assert_equals(e.data, "t1start, t1end, promise, t2");
+});
+</script>
diff --git a/dom/workers/WorkerPrivate.cpp b/dom/workers/WorkerPrivate.cpp
index 9992e71b24c6..f363e91fc8ff 100644
--- a/dom/workers/WorkerPrivate.cpp
+++ b/dom/workers/WorkerPrivate.cpp
@@ -6745,6 +6745,10 @@ WorkerPrivate::RunExpiredTimeouts(JSContext* aCx)
       }
     }
 
+    // Since we might be processing more timeouts, go ahead and flush
+    // the promise queue now before we do that.
+    Promise::PerformMicroTaskCheckpoint();
+
     NS_ASSERTION(mRunningExpiredTimeouts, "Someone changed this!");
   }