Ephemerons are based around WeakMember which may just be null at the
time the pair is considered for liveness. Bail out of marking for null
keys, as they write barrier would anyways make the value strong when
marking the key.
Bug: chromium:1056170
Change-Id: If8775a370824b88fc67fa479a0c0893985fbf5f4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2692571
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72714}
Embedders forward the Value in TraceEphemeron as Member reference (as
depicted in the API docs). Add TraceTrait<Member<T>> that forwards to
TraceTrait<T> accordingly, supporting the intended use case.
Bug: chromium:1056170
Change-Id: I3b247cb3553ae34d9ff5393aefeaec24068e78c2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2656255
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72412}
The TraceTrait<T> checks whether T is a mixin to decide whether we can
use the fast (arithmetic) or slow (bitmap) method to look up the HoH.
Before this CL, the mixin application would also be considered as a
mixin because the marker is present, resulting in all cases going
through the object start bitmap.
The initial intention was to use the arithmetic for the mixin
applications as those inherit from GCed.
Bug: chromium:1056170
Change-Id: Ib0ba82a8f98e0481d2879ebacc1ca9bd9e675858
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2643395
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72262}
There are several use cases related to collections that require
tracing a raw pointer.
Bug: chromium:1056170
Change-Id: I162b5380e7bddd7be62cbc74aa0031c8695220a7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2643385
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72250}
Adds traits for checking for Member,WeakMember, and UntracedMember
types.
This allows the embedder to specify its own traits and restrictions
around cppgc types.
Bug: chromium:1056170
Change-Id: Ibe60b774128f72f1398267edd81233c50fca6eb7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2532299
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71121}
This is a reland of 90ea9b35cb
Original change's description:
> cppgc: Port backing store compaction.
>
> This CL ports the existing backing store compaction algorithm from
> blink. It does not attempt to improve on the existing algorithm.
>
> Currently only unified heap uses the compaction implementation. It is
> never triggered through standalone GCs.
>
> The compaction implementation resides within an internal "subtle" namespace.
>
> Bug: v8:10990
> Change-Id: I4aa781db1b711e7aafc34234c4fb142de84394d7
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485228
> Commit-Queue: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70714}
Bug: v8:10990
Change-Id: I527c2042a26648d058bfe4d355527cce9a3eeadc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2492331
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70736}
This reverts commit 90ea9b35cb.
Reason for revert: https://ci.chromium.org/p/v8/builders/ci/V8%20Mac64%20-%20debug/31274?
Original change's description:
> cppgc: Port backing store compaction.
>
> This CL ports the existing backing store compaction algorithm from
> blink. It does not attempt to improve on the existing algorithm.
>
> Currently only unified heap uses the compaction implementation. It is
> never triggered through standalone GCs.
>
> The compaction implementation resides within an internal "subtle" namespace.
>
> Bug: v8:10990
> Change-Id: I4aa781db1b711e7aafc34234c4fb142de84394d7
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485228
> Commit-Queue: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70714}
TBR=mlippautz@chromium.org,bikineev@chromium.org,omerkatz@chromium.org
Change-Id: Iadae1ee0c6c0400f0e1a0a3805be5316a1d4b979
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10990
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2492330
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70716}
This CL ports the existing backing store compaction algorithm from
blink. It does not attempt to improve on the existing algorithm.
Currently only unified heap uses the compaction implementation. It is
never triggered through standalone GCs.
The compaction implementation resides within an internal "subtle" namespace.
Bug: v8:10990
Change-Id: I4aa781db1b711e7aafc34234c4fb142de84394d7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2485228
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70714}
This CL adds TraceWeakContainer and VisitWeakContainer to the Visitor
api. It also introduces the weak_container_worklist_ used to force
re-tracing of weak containers that are reachable from stack.
Bug: chromium:1056170
Change-Id: I4ba75bd64939b8df9ece7422828a5ac647b03fd1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2491022
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70708}
Align the library with the current blink implementation.
TraceStrongly takes a WeakMember and strongifies it so that the
referenced objects is retained.
This is used in blink during tracing of some weak collections.
Bug: chromium:1056170
Change-Id: I306f84fc37a856d309bccc7f544750abb2bdc7c9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2479003
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Auto-Submit: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70561}
Cppgc exposes EphemeronPair that contains a WeakMember key and a Member
value and can be used to denote ephemeron semantics in the standalone
library.
Tracing EphemeronPairs goes through TraceEphemeron that is exposed on
the api for the blink usecase.
Bug: chromium:1056170
Change-Id: I9fbaa284fa2034248cdf36ea8b0cd5be6a55f676
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467842
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70525}
Tracing JSMembers uses the bailout mechanism.
The bailout is implemented as a dynamic mechanism named
DeferTraceToMutatorThreadIfConcurrent that is called from
relevant Trace methods.
Bug: chromium:1056170
Change-Id: I90e6feae25c4c832be256693f9e44a963a6794b7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2426613
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70429}
Adds a cross-thread reference for strongly and weakly retaining
objects on a thread other than the thread that owns the object.
The intended use of the reference is by setting it up on the
originating thread, holding the object alive from another thread, and
ultimately accessing the object again on the originating thread.
The reference has known caveats:
- It's unsafe to use when the heap may terminate;
- It's unsafe to transitively reach through the graph because of
compaction;
Change-Id: I84fbdde69a099eb54af5b93c34e2169915b17e64
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2436449
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70428}
For cross-thread handling we require the atomic marking pause to
provide an atomically consistent view of markbits and weak references.
This is ensured by locking the whole atomic pause from entering to
weak processing.
This CL move ProcessWeakness() into FinishMarking() which allows to
nicely scope the upcomming lock from EnterAtomicPause() to
LeaveAtomicPause(). The alternative is requiring the caller to ensure
proper locking which is harder than ensuring that the Marker is
consistent.
Bug: chromium:1056170
Change-Id: Ib6028a0d76fcf9422c4a0d422fec3d568f106bf2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2442620
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70259}
- Adds JSVisitor that is used for unified heap marking.
- Adds JSMember as supported reference type that also encapsulates a
write barrier in future. JSMember is a replacement for
TracedReference which can be deprecated with EmbedderHeapTracer once
the library is used to handle unified heap collections.
The dispatch for v8::JSMember on cppgc::Visitor is provided through a
specialization of TraceTrait.
Bug: chromium:1056170
Change-Id: I60d976ae66db3e5fa2e690a21627bdcb8c6871af
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2284488
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68716}
Split off ConservativeMarkingVisitor from MarkingVisitor.
After this change, MarkingVisitor and ConservativeMarkingVisitor are
types that are instantiated with Marking and merely forward to
MarkingState accrodingly. The two marking-related visitors can be
passed along as interface types cppgc::Visitor and
ConservativeTracingVisitor, respectively.
Change-Id: Iad103dc3053c61d1a104a8802edd420d21cdf935
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2270538
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68661}
This is a reland of e0c1a349ea
The issue was passing SentinelPointer (== +1) through T*.
The fix is disabling cfi unrelated cast diagnostic for the bottlenecks
(Get()). This means that nullptr is treated the same as
kSentinelPointer.
The alternative would be a DCHECK that Get() does not return
kSentinelPointer and adjusting all Member and Persistent logic that
uses Get() to work on void*. This is quite intrusive as it involves
Swap(), heterogeneous assignments, comparisons, etc.
Original change's description:
> cppgc: Properly clear (Weak)Peristent and WeakMember pointers
>
> The CL addresses two issues with (Weak)Persistent and WeakMember:
> 1. (Weak)Persistent pointers are cleared on heap teardown. Before this
> CL the pointers would contain stale values which could lead to UAF.
> 2. WeakPersistent and WeakMember are cleared using a combination of
> internal clearing methods and mutable fields which avoids the use
> of const_cast<>.
>
> Bug: chromium:1056170
> Change-Id: Ibf2b0f0856771b4f6906608cde13a6d43ebf81f3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2248190
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68394}
Bug: chromium:1056170
Change-Id: I3d74b43464c2973df1956f51b1419d755dd9f519
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2250240
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68426}
The CL addresses two issues with (Weak)Persistent and WeakMember:
1. (Weak)Persistent pointers are cleared on heap teardown. Before this
CL the pointers would contain stale values which could lead to UAF.
2. WeakPersistent and WeakMember are cleared using a combination of
internal clearing methods and mutable fields which avoids the use
of const_cast<>.
Bug: chromium:1056170
Change-Id: Ibf2b0f0856771b4f6906608cde13a6d43ebf81f3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2248190
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68394}
This allows embedding objects in each other and recursively trace
through them.
Bug: chromium:1056170
Change-Id: I4e4ae4c1669109c01003cb6b69797cf271a74033
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2198977
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67841}
This CL introduces:
- Worklist
- MarkingHandler to manage gc marking phase
- Integration into CollectGarbage for atomic pause GC
- MarkingVisitor for main thread marking
Still missing from this CL:
- Proper handling for stack scanning
- Handling of previously not fully constructed objects
Bug: chromium:1056170
Change-Id: I70ac8534dfb898777cf3a06e3119cac8072174fd
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2170526
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67642}
- Fixes includes to be relative to include/ which allows embedders
to just add V8's include directory to get started.
- Adds public target for the library as "cppgc".
Bug: chromium:1056170
Change-Id: Iec9b644e20016a5d7281275b739821a050fd2540
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2157366
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67278}
This adds support for custom weak callbacks through static callbacks and
instance methods.
Bug: chromium:1056170
Change-Id: Ie4bd32539e0d933b192f07edb2d45e0070c2128d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2148784
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67167}
A few notes:
1) Oilpan is a generic library, meaning that it can work with arbitrary
user types. The library is split in type-aware (include/) and
type-erased (src/) parts. The former comprises a lot of code that still
needs to be defended with dchecks;
2) Macros are prefixed with CPPGC_, so that they don't clash in the user
code with similar macros from other libraries;
3) The macros simply forward requests to V8 so that dcheck handlers can
be configured uniformly;
4) The CL doesn't contain CHECK_EQ and friends, but they can be added
later if needed.
Bug: chromium:1056170
Change-Id: I68e6f663247705233eaf030384164d81e53071e1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2148774
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67129}
Provides the infrastructure to register weak callbacks for
WeakMember<T> through visitor. The WeakCallbackInfo broker is used to
query objects for liveness. In a future CL the same broker object is
passed to custom weak callbacks.
Change-Id: I8b5a66354e0e457521989d40ae64a9558c339503
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2142265
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67109}
This CL adds the necessary traits to dispatch from Member through a
visitor implementation for GarabgeCollected and GarbageCollectedMixin.
Bug: chromium:1056170
Change-Id: I12680335044aaa842639fb5e8f9a3ac61587f51a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2138431
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67041}
