In the spec, WeakRefs that are dereferenced are kept alive until there's
no JS on the stack, and then the host is expected to call
ClearKeptObjects to clear those strong references [1]. HTML calls
ClearKeptObjects at the end of a PerformMicrotaskCheckpoint [2].
In V8, leaving this up to the embedder is error prone in the same way
the deprecated FinalizationGroup callback APIs were error prone: it
depends on the embedder doing the right thing. This CL moves the call to
ClearKeptObjects to be after running of microtasks within V8.
However, the Isolate::ClearKeptObjects API should not be removed or
deprecated in case an embedder uses an entirely custom MicrotaskQueue
implementation and invokes MicrotaskQueue::PerformCheckpoint manually.
[1] https://tc39.es/proposal-weakrefs/#sec-clear-kept-objects
[2] https://github.com/whatwg/html/pull/4571
Bug: v8:8179
Change-Id: Ie243804157b56241ca69ed8fad300e839a0c9f75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2055967
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66327}
Change unregister tokens to be held weakly instead of strongly. This
enables the use case for an object to be used as its own unregister
token.
To avoid using an ephemeron table, FinalizationGroup's key_map is
changed to key off unregister tokens' identity hashes. Because hashes
may collide, a single key list may rarely contain multiple tokens. When
a FinalizationGroup WeakCell's token becomes unreachable, during GC, it
is removed from the the doubly linked key list and removed from the key
map if it had a unique key.
Bug: v8:8179
Change-Id: If88fd2ab196e3f9a287990ae345117a0abb2f04d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1970493
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65532}
Previously, this was run as a microtask and this CL changes it to run
as a separate task as mandated by the current WeakRef spec.
This CL also introduces a FinalizationGroup type to the V8 API
representing the JSFinalizationGroup. This has a `Cleanup`
function that runs the cleanup callback associated with it.
SetHostCleanupFinalizationGroupCallback is added to set
the embedder defined HostCleanupFinalizationGroupCallback.
ClearKeptObject is exposed on the v8::Isolate to reset the strongly
held set of objects.
The general workflow is the following:
(a) When the GC notices that a given finalization group has dirty
cells, it calls HostCleanupFinalizationGroupCallback with the given
finalization group.
(b) As part of HostCleanupFinalizationGroupCallback, the embedder
enqueues a task that at some point later calls
FinalizationGroup::Cleanup.
(c) At some point in the future, FinalizationGroup::Cleanup is called,
which runs the cleanup callback of the finalization group.
This patch also includes d8 changes to use these new APIs. Currently,
d8 cycles through the enqueued finalization groups after a synchronous
turn (and it's microtask checkpoint) and runs the cleanup callbacks.
Change-Id: I06eb4da2c103b2792a9c62bc4b98fd4e5c4892fc
Bug: v8:8179
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1655655
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62984}
This CL was generated by an automatic clang AST rewriter using this
matcher expression:
callExpr(
callee(
cxxMethodDecl(
hasName("operator->"),
ofClass(isSameOrDerivedFrom("v8::internal::Object"))
)
),
argumentCountIs(1)
)
The "->" at the expression location was then rewritten to ".".
R=jkummerow@chromium.orgTBR=mstarzinger@chromium.org,verwaest@chromium.org,yangguo@chromium.org
Bug: v8:9183, v8:3770
No-Try: true
No-Tree-Checks: true
Change-Id: I0a7ecabdeafe51d0cf427f5280af0c7cab96869e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1624209
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61764}
(The bug didn't affect any functionality; we just left detached WeakCells in
inconsistent state.)
BUG=v8:8179
Change-Id: I28f6c27532383b94bdfd746db903096f1dc6f1cc
Reviewed-on: https://chromium-review.googlesource.com/c/1447651
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59255}
The test defined a function called "Register" which clashes with other functions
with the same name.
NOTRY=true
TBR=sigurds@chromium.org
BUG=v8:8179
Change-Id: I7ddfc481cd1de750272de7b43e2e7f9fe26626a9
Reviewed-on: https://chromium-review.googlesource.com/c/1445982
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59208}
Merging the temporary HeapObjectPtr back into HeapObject.
Bug: v8:3770
Change-Id: I5bcd23ca2f5ba862cf5b52955dca143e531c637b
Reviewed-on: https://chromium-review.googlesource.com/c/1386492
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58410}
+ fixing other files which were depending on context-inl.h pulling in the
missing includes.
BUG=v8:7490,v8:8238
Change-Id: I90d37599bdfb69ac8fd7e62b8fb78d9d77c77234
Reviewed-on: https://chromium-review.googlesource.com/c/1349277
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57775}
as part of the continuing quest to get rid of Object*/Object**.
This is a fairly mechanical replacement of Object**/MaybeObject** with
wrapper objects carrying the same data. No change in behavior is intended.
Overloaded operators are provided to minimize code churn.
Bug: v8:3770
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Change-Id: I76cee82b8bf2dd80a1b66f09dd2bb2b65038eeb7
Reviewed-on: https://chromium-review.googlesource.com/c/1287889
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56920}
These test mainly the data structures of JSWeakFactory / JSWeakCell.
BUG=v8:8179
Change-Id: I20ffd07c18bbb2e21c69d11aa65d1e245203cc82
Reviewed-on: https://chromium-review.googlesource.com/c/1267939
Commit-Queue: Marja Hölttä <marja@chromium.org>
Reviewed-by: Sathya Gunasekaran <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56569}
