fix($rootScope): when adding/removing watchers during $digest #15424
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Previously, adding a watcher during a `$digest` (i.e. from within a watcher), would result in the next watcher getting skipped. Similarly, removing a watcher during a `$digest` could result in the current watcher being run twice (if the removed watcher had not run yet in the current `$digest`). This commit fixes both cases by keeping track of the current watcher index during a digest and properly updating it when adding/removing watchers. Fixes angular#15422
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looks good to me, i will test (patch my 158 install) with that code tomorrow to see how it works but at first sight that should fix it one thing: "should not skip watchers when removing a watcher during digest'" thats not really the case, for removing its not really skipping right? its more about not executing the same watch again? i think this check: expect(log).toEqual([1, 2, 1, 2]); would be without your fix: expect(log).toEqual([1, 1, 2, 1, 2]); right? |
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i patched my 158 install and i don't need the evalAsync patch that i now had in my code |
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We should definitely test this for performance. |
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the only thing that is really changed for digest() is that instead of a local variable we now have a scoped variable on a object. Anybody know what that lookup/assignment cost? Is that really measurable ? i think the code in add/remove watch shouldn't be to much to worry about because that shouldn't really be called in high volume (like the digest cycle) |
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Yeah, the only change that matters (performance-wise) is the switch from a local variable to a property lookup. I doubt it will have any noticeable impact (compared to all other operations typically run alongside). I meassured the duration of the digest (without any changes) in a finished instance of the |
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LGTM |
Previously, adding a watcher during a `$digest` (i.e. from within a watcher), would result in the next watcher getting skipped. Similarly, removing a watcher during a `$digest` could result in the current watcher being run twice (if the removed watcher had not run yet in the current `$digest`). This commit fixes both cases by keeping track of the current watcher index during a digest and properly updating it when adding/removing watchers. Fixes #15422 Closes #15424
Previously, adding a watcher during a `$digest` (i.e. from within a watcher), would result in the next watcher getting skipped. Similarly, removing a watcher during a `$digest` could result in the current watcher being run twice (if the removed watcher had not run yet in the current `$digest`). This commit fixes both cases by keeping track of the current watcher index during a digest and properly updating it when adding/removing watchers. Fixes #15422 Closes #15424
Previously, adding a watcher during a `$digest` (i.e. from within a watcher), would result in the next watcher getting skipped. Similarly, removing a watcher during a `$digest` could result in the current watcher being run twice (if the removed watcher had not run yet in the current `$digest`). This commit fixes both cases by keeping track of the current watcher index during a digest and properly updating it when adding/removing watchers. Fixes angular#15422 Closes angular#15424
What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)
Bug fix.
What is the current behavior? (You can also link to an open issue here)
Adding a watcher during a
$digest(i.e. from within a watcher), results in the next watcher getting skipped. Similarly, removing a watcher during a$digestcould result in the current watcher being run twice (if the removed watcher had not run yet in the current$digest).What is the new behavior (if this is a feature change)?
Adding/Removing watchers during a
$digestworks as expected.Does this PR introduce a breaking change?
No.
Please check if the PR fulfills these requirements
Docs have been added / updated (for bug fixes / features)Other information:
This commit fixes both cases by keeping track of the current watcher index during a digest and properly updating it when adding/removing watchers.
There might be a tiny extra overhead due to looking up
$$digestWatchIndexonscope.$$watchersduring the$digest.Fixes #15422