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}
This CL introduces concurrent marking to the cppgc library.
The CL includes:
(*) Split MarkingState to mutator thread and concurrent thread.
(*) Split MarkingVisitor to mutator thread and concurrent thread.
(*) Introduce ConcurrentMarker for managing concurrent marking.
(*) Update unified heap to support concurrent marking as well.
See slides 13 and 14 in the following link for class hierarchies:
https://docs.google.com/presentation/d/1uDiEjJ-f1VziBKmYcvpw2gglP47M53bwj1L-P__l9QY/
Bug: chromium:1056170
Change-Id: I6530c2b21613011a612773d36fbf37416c23c5e7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2424348
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@{#70352}
In construction objects don't have anything to sync with on the
allocation side since they weren't marked as fully constructed yet.
This could mean the initialization of the marking bit on the mutator
thread and setting the mark bit on a concurrent thread could race
(potentially resulting in losing the mark bit when the gc info index
overwrites it).
This CL fixes this issue by using a set of in construction objects.
In construction objects are no longer marked. Instead they are pushed
to the set and the heap object header is marked when they are popped
from the worklist. Since the set avoids duplicates, this allows us to
both avoid worklist explosion (due to pushing the same in construction
object multiple times) and avoid the data race on the mark bit.
This CL uses an unordered_set to record objects. Synchronization uses
a lock, which could be costly but is not expected to be obtained often.
Bug: chromium:1056170
Change-Id: I366b59f476c166ff06e15b280df9e846034cc6cf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2437388
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70282}
This CL migrates cppgc to use Ulan's new worklist implementation.
Since there is no central segments array anymore, we cannot rely on
getting the same view (now renamed to Local) given the same task id.
To avoid creating many short lived segments (e.g. for write barriers)
marking state now holds local views for all worklists and provides
access to them.
Bug: chromium:1056170
Change-Id: Id19fe1196b79ed251810e91074046998dc2a9177
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2390771
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69767}
Starting marking required Creating a Marker and calling StartMarking.
StartMarking should always have been called immediately after creating
the marker.
Since markers are not persisted between GC (a marker exists only while
marking is in progress), it makes sense to start marking implicitly when
a marker is created.
Calling StartMarking in MarkerBase ctor is inadvisable since subclasses
might still to initialize fields.
Using MarkerFactory instead guarantees that StartMarking is always
called immediately after creating a Marker.
Bug: chromium:1056170
Change-Id: Icbf11afd848e1618c204ca6bf951600b3ae9fef2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2375199
Commit-Queue: 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@{#69601}
This CL adds a basic implementation of incremental marking for standalone GC.
Followup CLs include:
* Use bytes instead of time as deadline
* Port incremental marking schedule from blink
* Mark on allocation
* Guarantees for progres/termination for standalone GC
* etc...
Calling StartIncrementalGarbageCollection triggers StartMarking which
schedules incremental marking as non-nestable tasks.
For unified heap, marking will continue running until it runs out of
work but it won't finalize independently.
For standalone, when incremental runs out of work it will schedule a new
task in which it will finalize marking and trigger the rest of the GC.
Users of standalone can also force finalization before incremental
marking as finished using FinalizeIncrementalGarbageCollectionIfRunning.
Calling CollectGarbage would also finalize an on-going incremental GC
if one exists. Otherwise it will trigger an atomic GC.
See the following doc for explanation of the various methods:
https://docs.google.com/document/d/1ZhJY2fOoD8sH53ZxMh2927Zl8sXqA7azJgcQTWx-YKs/edit?usp=sharing
Bug: chromium:1056170
Change-Id: I75ead414eb9da9f8b7f71c4638b9830fce7708ca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2298009
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69480}
This is a revival of https://chromium-review.googlesource.com/c/v8/v8/+/2228332
The CL establishes the following:
*) Objects are marked before being pushed to the worklists.
*) Live bytes are always accounted after tracing an object (i.e. move
from Gray to Black below).
*) Previously not fully constructed objects are traced immediately
instead of pushed to the marking worklist.
This establishes the following invariants for all marking worklists:
1) White = !object.is_marked() && !worklist.contains(object)
2) Gray = object.is_marked() && worklist.contains(object)
3) Black = object.is_marked() && !worklist.contains(object)
Bug: chromium:1056170
Change-Id: I821573b3fbc057e6ffb836154271ff986ecb4d2b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2336797
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69268}
This CL removes the GetTraceDescriptor virtual call from garbage
collected mixins and replaces it with querying the object start
bitmap.
The CL also removes the mixin macros which are now no longer needed.
Bug: chromium:1056170
Change-Id: I27ed299f93025d09a3bb3f0d17b14bed3c200565
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2287508
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68787}
Split off MarkingState from MarkingVisitor.
With this CL the marking implementation is moved to "MarkingState"
which is the new bottleneck for marking a single object.
MarkingVisitor merely forwards to MarkingState, which knows how to set
the markbit and add the object to the worklist accordingly. This
allows to have a "UnifiedHeapMarkingVisitor" in future which can
easily reuse Marking to provide C++ marking.
Change-Id: I87ebbe37e8e8cd841e872cae9dc3490e2b55c4dd
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2270172
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68660}
Unified heap support in V8 requires having another (at least internal)
heap that implements a unfied garbage collection strategy. This will
not re-use the already existing cppgc::Heap because there should be no
way in creating such a heap externally or scheduling stand-alone
garbage collections.
In order to have a common token, this CL introduces AllocationHandle
which can be passed to MakeGarbageCollected to allocate C++ objects.
V8 (soon) and the stand-alone heap both have methods to retrieve such
a handle.
This works around a problem with creating diamond class hierarchies
when a base class would be exposed on the public API level.
Fast paths for Blink are still possible because allocation handles can
be cached the same way (e.g. global, or TLS) as a heap can be cached.
Tbr: yangguo@chromium.org
Bug: chromium:1056170
Change-Id: I8e9472a2c24ef82d1178953e8429b1fd8a2344bc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2238027
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68310}
