This patch includes the follow two minor optimizations:
1) When Object.unobserve-ing, instead of deleting from changeObservers, set the index position to null, and null-check when iterating elsewhere
2) Isolate creation of null-proto objects inside a utility function
These former (deleting) was clearly showing up in d8 --prof traces and the later was preventing optimization of containing functions because of non-standard literal. Combined, on MDV construction/teardown benchmark, saves about 10%.
Note that this patch also cleans up retrieving objectInfo inside a utility function.
R=rossberg@chromium.org, rossberg
BUG=
Review URL: https://codereview.chromium.org/123523002
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18501 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Based on prototype at
https://github.com/rossberg-chromium/js-promise
which informed the latest spec draft version at
https://github.com/domenic/promises-unwrapping/blob/master/README.md
Activated by --harmony-promises.
Feature complete with respect to the draft spec, plus the addition of .when and .deferred methods. Final naming and other possible deviations from the current draft will hopefully be resolved soon after the next TC39 meeting.
This CL also generalises the Object.observe delivery loop into a simplistic microtask loop. Currently, all observer events are delivered before invoking any promise handler in a single fixpoint iteration. It's not clear yet what the final semantics is supposed to be (should there be a global event ordering?), but it will probably require a more thorough event loop abstraction inside V8 once we get there.
R=dslomov@chromium.org, yhirano@chromium.org
BUG=
Review URL: https://codereview.chromium.org/64223010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18113 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This change is mostly straightforward: for 'normal' sorts of change records,
simply don't deliver a changeRecord to a given observer callback if an access
the callback's Context is not allowed to "GET" or "HAS" changeRecord.name on
changeRecord.object, or if ACCESS_KEYS is disallowed.
For 'splice' records, the question of whether to hand it to an observer is trickier, since
there are multiple properties involved, and multiple types of possible information leakage.
Given that access-checked objects are very rare (only two in Blink, Window and Location),
and that they are not normally used as Arrays, it seems better to simply not emit any splice
records for such objects rather than spending lots of logic to attempt to avoid information
leakage for something that may never happen.
BUG=v8:2778
R=rossberg@chromium.org
Review URL: https://codereview.chromium.org/22962009
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16663 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Observation in the normal case (Object.observe, default accept types, one observer) now allocates fewer objects and unobservation no longer needs to scan and splice an InternalArray -- making the combined speed of observe/unobserve about 200% faster.
This patch implements the following optimizations:
-objectInfo is initially created without any connected objects or arrays. The first observer is referenced directly by objectInfo, and when a second observer is added, changeObservers converts to a mapping of callbackPriority->observer, which allows for constant time registration/de-registration.
-observer.accept and objectInfo.performing are conceptually the same data-structure. This is now directly represented as an abstract "TypeMap" which can later be optimized to be a smi in common cases, (e.g: https://codereview.chromium.org/19269007/).
-objectInfo observers are only represented by an object with an accept typeMap if the set of accept types is non-default
R=rossberg@chromium.org
Review URL: https://codereview.chromium.org/19541010
Patch from Rafael Weinstein <rafaelw@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16629 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Observation in the normal case (Object.observe, default accept types, one observer) now allocates fewer objects and unobservation no longer needs to scan and splice an InternalArray -- making the combined speed of observe/unobserve about 200% faster.
This patch implements the following optimizations:
-objectInfo is initially created without any connected objects or arrays. The first observer is referenced directly by objectInfo, and when a second observer is added, changeObservers converts to a mapping of callbackPriority->observer, which allows for constant time registration/de-registration.
-observer.accept and objectInfo.performing are conceptually the same data-structure. This is now directly represented as an abstract "TypeMap" which can later be optimized to be a smi in common cases, (e.g: https://codereview.chromium.org/19269007/).
-objectInfo observers are only represented by an object with an accept typeMap if the set of accept types is non-default
R=rossberg@chromium.org
Committed: https://code.google.com/p/v8/source/detail?r=16343
Review URL: https://codereview.chromium.org/19541010
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16539 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Observation in the normal case (Object.observe, default accept types, one observer) now allocates fewer objects and unobservation no longer needs to scan and splice an InternalArray -- making the combined speed of observe/unobserve about 200% faster.
This patch implements the following optimizations:
-objectInfo is initially created without any connected objects or arrays. The first observer is referenced directly by objectInfo, and when a second observer is added, changeObservers converts to a mapping of callbackPriority->observer, which allows for constant time registration/de-registration.
-observer.accept and objectInfo.performing are conceptually the same data-structure. This is now directly represented as an abstract "TypeMap" which can later be optimized to be a smi in common cases, (e.g: https://codereview.chromium.org/19269007/).
-objectInfo observers are only represented by an object with an accept typeMap if the set of accept types is non-default
R=rossberg@chromium.org
Review URL: https://codereview.chromium.org/19541010
Patch from Rafael Weinstein <rafaelw@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16343 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
https://codereview.chromium.org/19541010/
The main problem is that if you called Object.getNotifier(obj) on an object, %SetObserved(object) would never get called on it, and thus it would be unobservable (new test added for this).
Additionally, Runtime::SetObserved was asserting obj->IsJSObject() which would fail if called on a proxy.
It just happens that our existing test always called getNotifier() before Object.observe on proxies, and thus we never previously attempted to transition the map of a proxy.
Both issues are now fixed and properly tested.
R=rossberg@chromium.org
Review URL: https://codereview.chromium.org/21891008
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@16074 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch allows callbacks to lazily allocate the InternalArray which is used to store pendingChangeRecords. This moves some of the expense of observation to the case where changes actually occurred.
When there are no pendingChangeRecords, the callbackInfo structure is a number which is the callbacks priority. Whenever a changeRecord is enqueued to the callback, it "normalizes" to be an InternalArray with a priority property. Immediately before its changeRecords are delivered, it returns to its optimized state.
---
Note: Naming confusion resolved:
This patch corrects some naming confusion in object-observe.js. Previously, we used the terms "callback" and "observer" to mean roughly the same thing, and overloaded the term "observer" to be both the callback itself and the *registration* on a object to observe (which now includes an accept map).
This patch resolves this confusion:
"object" (objectInfo, objectInfoMap): This refers to the observed object and its structures
"callback" (callbackInfo, callbackInfoMap): This refers to the callback to whom change records may be delivered
"observer" (objectInfo.changeObservers): This refers to a registration to observe a given object by a given callback with the specified accept list.
---
R=rossberg@chromium.org
Review URL: https://codereview.chromium.org/19132002
Patch from Rafael Weinstein <rafaelw@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15682 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This patch enables objects to undergo a single transition when they become observed, avoiding the need to create a new map for every observed objects.
Observed objects which become unobserved does not cause another map transition and unobserved does not clear the observed bit on the map. The unobserved object.
R=verwaest@chromium.org
Review URL: https://codereview.chromium.org/18221006
Patch from Rafael Weinstein <rafaelw@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15650 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
object-observe.js uses weak maps to add "hidden" properties to
objects. Previously, the hash tables it was using weren't actually
weak. This patch changes the existing runtime functions to create
instances of JSWeakMap instead of exposing ObjectHashTable directly.
Review URL: https://codereview.chromium.org/12092079
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13591 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
The approach in this change is to handle the unwrapping/wrapping of the global object transparently with respect to the JS implementation of Object.observe. An alternate approach would be to add a runtime method like %IsJSGlobalProxy and %UnwrapJSGlobalProxy, but it seems ugly to give JS (even implementation JS) access to the unwrapped global.
BUG=v8:2409
Review URL: https://codereview.chromium.org/11414094
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@13142 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
To preserve ordering guarantees during end-of-turn delivery, Object.deliverChangeRecords needs to remove the delivered-to observer from the list of active observers.
The added test demonstrates this behavior.
Review URL: https://codereview.chromium.org/11410046
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12951 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This CL has two parts: the first is the logic itself, whereby each observer callback is assigned
a "priority" number the first time it's passed as an observer to Object.observe(), and that
priority is used to determine the order of delivery.
The second part invokes the above logic as part of the API, when the JS stack winds down to
zero.
Added several tests via the API, as the delivery logic isn't testable from a JS test
(it runs after such a test would exit).
Review URL: https://codereview.chromium.org/11266011
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12902 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
This requires adding a new JSObject to the strong root list and populating it from
object-observe.js. The main other change is that we now directly use ObjectHashTable
from JS rather than using WeakMap, since using the latter would end up leaking whichever
Context initialized that observation state.
Added a test via the API showing that different contexts all end up working on the same state.
Review URL: https://codereview.chromium.org/11274014
Patch from Adam Klein <adamk@chromium.org>.
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12873 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
In more detail:
- Set observation bit for observed objects (and make NormalizedMapCache respect it).
- Mutation of observed objects is always delegated from ICs to runtime.
- Introduce JS runtime function for notifying generated changes.
- Invoke this function in the appropriate places (including some local refactoring).
- Inclusion of oldValue field is not yet implemented, nor element properties.
Also, shortened flag to --harmony-observation.
R=verwaest@chromium.org
BUG=
Review URL: https://codereview.chromium.org/11347037
git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12867 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
