Bug 83951 – [Chromium] CCLayerTreeHostTest racyness from beginTest()

• Component: New Bugs
• Status: RESOLVED WONTFIX

[Daniel Sievers]

For example, putting a sleep() before the call to postSetNeedsCommitToMainThread() in CCLayerTreeHostTestScrollMultipleRedraw's beginTest() causes it to fail.
I think it's because setScrollable() having been called earlier races with the second 'needs commit' task, while the test expects a certain number of commits (and even a draw without commit).

Also some tests might do other modifications to the tree that implicitly cause a 'needs commit' to be posted.

Why do tests use postSetNeeds*ToMainThread() inside beginTest() which already runs on the main thread. Does that cause more potential for races?

What if a test does this

void beginTest()
{
   // modify tree, causes set needs commit and eventually triggers beginCommitOnCCThread()
   //...
A: // set some other internal state X
}

virtual void beginCommitOnCCThread()
{
B:  // does something that relies on state X
}

Can A race with B?

Maybe we need some safety barriers in the test harness for beginTest().

[Nat Duca]

Daniel, can we assign you as owning this bug?

[Daniel Sievers]

Sure, updated.

[Stephen Chenney]

https://code.google.com/p/chromium/issues/detail?id=231317