Users of padded objects must know the actual object size for
implementing custom finalizers.
Bug: chromium:1056170
Change-Id: I0ddf9066cfece0a8d18a9e6fd985d09449eea92a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2644941
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72269}
This CL introduces cppgc::HistogramRecorder api which is similar to the
v8::metrics::Recorder api and is used by cppgc to report histogram
samples to embedders. Embedders should implement the api if they want to
collect histograms and provide an instance of it on heap creation.
CppHeap uses an adaptor class that implements the HistogramRecorder api
and is used to forward the relevant info to the relevant
v8::metrics::Recorder.
The api used 3 data structures: 2 for incremental steps that need to be
reported as they come (marking and sweeping) and 1 for the end of a GC
cycle that aggregates statistics over the entire cycle.
The data structure only provide the "raw" samples (e.g. atomic mark
time, incremental mark time, etc...). The embedder is expected to
compute aggregate histogram on its own (e.g. overall marking time).
Bug: chromium:1056170
Change-Id: If63ef50a29a21594f654edb83084598980d221ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2642258
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@{#72256}
Provide a way to trigger a write barrier when updating the embedder
fields. In future, such a mechanism should be encapsulated into V8.
Bug: chromium:1056170
Change-Id: I4e43362993c3e58d5bebdd58a7d46a39c0aa4f06
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2640419
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@{#72227}
Add a dependency to a cppgc target for the the cppgc unit tests sources
so that the header files are used correctly. Previously it was working
because it added the external config which sets up the include
directories correctly, but would fail if the v8-gn.h file was not
generated quickly enough or if the cppgc_unittests_sources was built on
its own.
Bug: v8:11292
Change-Id: If12be4809b59b8dd5705468ad0343a1118547092
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2640458
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72222}
This is a reland of 1694925c72
Minor fix to linkage for constexpr.
TBR=ahaas@chromium.org,neis@chromium.org
Original change's description:
> Reland "[compiler][wasm] Align Frame slots to value size"
>
> This is a reland of cddaf66c37
>
> Original change's description:
> > [compiler][wasm] Align Frame slots to value size
> >
> > - Adds an AlignedSlotAllocator class and tests, to unify slot
> > allocation. This attempts to use alignment holes for smaller
> > values.
> > - Reworks Frame to use the new allocator for stack slots.
> > - Reworks LinkageAllocator to use the new allocator for stack
> > slots and for ARMv7 FP register aliasing.
> > - Fixes the RegisterAllocator to align spill slots.
> > - Fixes InstructionSelector to align spill slots.
> >
> > Bug: v8:9198
> >
> > Change-Id: Ida148db428be89ef95de748ec5fc0e7b0358f523
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2512840
> > Commit-Queue: Bill Budge <bbudge@chromium.org>
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Reviewed-by: Andreas Haas <ahaas@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#71644}
>
> Bug: v8:9198
> Change-Id: Ib91fa6746370c38496706341e12d05c7bf999389
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2633390
> Commit-Queue: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72195}
Bug: v8:9198
Change-Id: I91e02b823af8ec925dacf075388fb22e3eeb3384
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2640890
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72209}
This reverts commit 1694925c72.
Reason for revert: Link error in CFI release build: https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Clusterfuzz%20Linux64%20CFI%20-%20release%20builder/19756/overview
Original change's description:
> Reland "[compiler][wasm] Align Frame slots to value size"
>
> This is a reland of cddaf66c37
>
> Original change's description:
> > [compiler][wasm] Align Frame slots to value size
> >
> > - Adds an AlignedSlotAllocator class and tests, to unify slot
> > allocation. This attempts to use alignment holes for smaller
> > values.
> > - Reworks Frame to use the new allocator for stack slots.
> > - Reworks LinkageAllocator to use the new allocator for stack
> > slots and for ARMv7 FP register aliasing.
> > - Fixes the RegisterAllocator to align spill slots.
> > - Fixes InstructionSelector to align spill slots.
> >
> > Bug: v8:9198
> >
> > Change-Id: Ida148db428be89ef95de748ec5fc0e7b0358f523
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2512840
> > Commit-Queue: Bill Budge <bbudge@chromium.org>
> > Reviewed-by: Georg Neis <neis@chromium.org>
> > Reviewed-by: Andreas Haas <ahaas@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#71644}
>
> Bug: v8:9198
> Change-Id: Ib91fa6746370c38496706341e12d05c7bf999389
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2633390
> Commit-Queue: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#72195}
TBR=bbudge@chromium.org,neis@chromium.org,ahaas@chromium.org
Change-Id: Ic94763925195c3a3552930e61a0eb0b7f0c0c756
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:9198
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2640474
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72197}
This is a reland of cddaf66c37
Original change's description:
> [compiler][wasm] Align Frame slots to value size
>
> - Adds an AlignedSlotAllocator class and tests, to unify slot
> allocation. This attempts to use alignment holes for smaller
> values.
> - Reworks Frame to use the new allocator for stack slots.
> - Reworks LinkageAllocator to use the new allocator for stack
> slots and for ARMv7 FP register aliasing.
> - Fixes the RegisterAllocator to align spill slots.
> - Fixes InstructionSelector to align spill slots.
>
> Bug: v8:9198
>
> Change-Id: Ida148db428be89ef95de748ec5fc0e7b0358f523
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2512840
> Commit-Queue: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71644}
Bug: v8:9198
Change-Id: Ib91fa6746370c38496706341e12d05c7bf999389
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2633390
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72195}
This reverts commit cddaf66c37.
Reason for revert: Multiple fuzzer failures
TBR=neis@chromium.org,ahaas@chromium.org
Original change's description:
> [compiler][wasm] Align Frame slots to value size
>
> - Adds an AlignedSlotAllocator class and tests, to unify slot
> allocation. This attempts to use alignment holes for smaller
> values.
> - Reworks Frame to use the new allocator for stack slots.
> - Reworks LinkageAllocator to use the new allocator for stack
> slots and for ARMv7 FP register aliasing.
> - Fixes the RegisterAllocator to align spill slots.
> - Fixes InstructionSelector to align spill slots.
>
> Bug: v8:9198
>
> Change-Id: Ida148db428be89ef95de748ec5fc0e7b0358f523
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2512840
> Commit-Queue: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Georg Neis <neis@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#71644}
TBR=bbudge@chromium.org,neis@chromium.org,ahaas@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
Bug: v8:9198
Change-Id: Ib26d016df6f30f333d30b5ac14eed9630bba8252
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2584200
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71703}
- Adds an AlignedSlotAllocator class and tests, to unify slot
allocation. This attempts to use alignment holes for smaller
values.
- Reworks Frame to use the new allocator for stack slots.
- Reworks LinkageAllocator to use the new allocator for stack
slots and for ARMv7 FP register aliasing.
- Fixes the RegisterAllocator to align spill slots.
- Fixes InstructionSelector to align spill slots.
Bug: v8:9198
Change-Id: Ida148db428be89ef95de748ec5fc0e7b0358f523
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2512840
Commit-Queue: Bill Budge <bbudge@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71644}
cppgc_unittests uses tracing (e.g. when setting the TracingController in
tests.h) and thus needs to depend on v8_tracing. It cannot inherit the
dependency since the cppgc_unittests_sources v8_source_set doesn't
depend on cppgc.
Bug: v8:11203
Change-Id: I7227f696f841132f174435751a42a02ff865df26
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2563658
Auto-Submit: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71453}
The CPPGC_BUILD_IN_V8 define (used for tracing) isn't propagated from
v8_base_without_compiler to cppgc_base, which breaks build with
perfetto. Instead use a gn args to specify standalone builds (defaulted
to false) and use that to choose the right tracing implementation.
Bug: chromium:1056170
Change-Id: I70bce819d45fb133b6f932a50a5d027e39f3e5b9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2555007
Auto-Submit: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71356}
This CL adds tracing scopes for the various cppgc classes.
Scopes use TRACE_EVENT_BEGIN and TRACE_EVENT_END macros to report trace
events. To do so they need to include trace-event.h. For unified heap
builds, trace-event.h forwards to v8's src/tracing/trace-event.h. For
other builds, trace-event.h provides a subset of
src/tracing/trace-event.h that covers just the parts used by cppgc.
This CL covers what we need for traces and blink gc metrics (up to
renaming events from BlinkGC.* to CppGC.*). UMA and UKM are not yet
handled.
Bug: chromium:1056170
Change-Id: Id92e84b27259ff0aadae7692f3d79d30896fb8e7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2540548
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@{#71284}
cppgc must support the same feature set as the existing unified heap
system, which requires support for wrapper-specific handling (drop on
Scavenge, merge in snapshot).
Replace JSMember by TracedReference to support IsRootForNonTracingGC()
optimizations out of the box. cppgc support for wrapper/wrappable
pairs will be added as followup.
Change-Id: I3c6eff2b8dce5b71b04b2bd75182eb8672079a64
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2498685
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@{#70801}
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}
This reverts commit fba14bde5f.
Reland fixes:
- const vector<const string> -> const vector<string>
Original message:
The following implements a snapshotting algorithm for C++ objects that
also filters strongly-connected components (SCCs) of only "hidden"
objects that are not (transitively) referencing any non-hidden
objects.
C++ objects come in two versions.
a. Named objects that have been assigned a name through NameProvider.
b. Unnamed objects, that are potentially hidden if the build
configuration requires Oilpan to hide such names. Hidden objects have
their name set to NameProvider::kHiddenName.
The main challenge for the algorithm is to avoid blowing up the final
object graph with hidden nodes that do not carry information. For that
reason, the algorithm filters SCCs of only hidden objects, e.g.:
... -> (object) -> (object) -> (hidden) -> (hidden)
In this case the (hidden) objects are filtered from the graph. The
trickiest part is maintaining visibility state for objects referencing
other objects that are currently being processed.
Main algorithm idea (two passes):
1. First pass marks all non-hidden objects and those that transitively
reach non-hidden objects as visible. Details:
- Iterate over all objects.
- If object is non-hidden mark it as visible and also mark parent
as visible if needed.
- If object is hidden, traverse children as DFS to find non-hidden
objects. Post-order process the objects and mark those objects as
visible that have child nodes that are visible themselves.
- Maintain an epoch counter (StateStorage::state_count_) to allow
deferring the visibility decision to other objects in the same
SCC. This is similar to the "lowlink" value in Tarjan's algorithm
for SCC.
- After the first pass it is guaranteed that all deferred
visibility decisions can be resolved.
2. Second pass adds nodes and edges for all visible objects.
- Upon first checking the visibility state of an object, all deferred
visibility states are resolved.
For practical reasons, the recursion is transformed into an iteration.
We do not use plain Tarjan's algorithm to avoid another pass over
all nodes to create SCCs.
Follow ups:
1. Adding wrapper nodes for cpp objects that are wrappables for V8
wrappers.
2. Adding detachedness information.
Bug: chromium:1056170
Change-Id: Ib47df5c912c57d644d052f209276e9d926cece0f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2480362
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70577}
This reverts commit 02849fd9de.
Reason for revert: Breaks Win64 MSVC bot and closes the tree - https://ci.chromium.org/p/v8/builders/ci/V8%20Win64%20-%20msvc/15416
Original change's description:
> cppgc-js: Add snapshot for C++ objects
>
> The following implements a snapshotting algorithm for C++ objects that
> also filters strongly-connected components (SCCs) of only "hidden"
> objects that are not (transitively) referencing any non-hidden
> objects.
>
> C++ objects come in two versions.
> a. Named objects that have been assigned a name through NameProvider.
> b. Unnamed objects, that are potentially hidden if the build
> configuration requires Oilpan to hide such names. Hidden objects have
> their name set to NameProvider::kHiddenName.
>
> The main challenge for the algorithm is to avoid blowing up the final
> object graph with hidden nodes that do not carry information. For that
> reason, the algorithm filters SCCs of only hidden objects, e.g.:
> ... -> (object) -> (object) -> (hidden) -> (hidden)
> In this case the (hidden) objects are filtered from the graph. The
> trickiest part is maintaining visibility state for objects referencing
> other objects that are currently being processed.
>
> Main algorithm idea (two passes):
> 1. First pass marks all non-hidden objects and those that transitively
> reach non-hidden objects as visible. Details:
> - Iterate over all objects.
> - If object is non-hidden mark it as visible and also mark parent
> as visible if needed.
> - If object is hidden, traverse children as DFS to find non-hidden
> objects. Post-order process the objects and mark those objects as
> visible that have child nodes that are visible themselves.
> - Maintain an epoch counter (StateStorage::state_count_) to allow
> deferring the visibility decision to other objects in the same
> SCC. This is similar to the "lowlink" value in Tarjan's algorithm
> for SCC.
> - After the first pass it is guaranteed that all deferred
> visibility decisions can be resolved.
> 2. Second pass adds nodes and edges for all visible objects.
> - Upon first checking the visibility state of an object, all deferred
> visibility states are resolved.
>
> For practical reasons, the recursion is transformed into an iteration.
> We do not use plain Tarjan's algorithm to avoid another pass over
> all nodes to create SCCs.
>
> Follow ups:
> 1. Adding wrapper nodes for cpp objects that are wrappables for V8
> wrappers.
> 2. Adding detachedness information.
>
> Change-Id: I6e127d2c6d65e77defe08e39295a2594f463b962
> Bug: chromium:1056170
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467854
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#70567}
TBR=ulan@chromium.org,mlippautz@chromium.org,bikineev@chromium.org,omerkatz@chromium.org
Change-Id: I64a2cf2259bdaed81f6e0f92bdcc7a1f0df4d197
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2479471
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70571}
The following implements a snapshotting algorithm for C++ objects that
also filters strongly-connected components (SCCs) of only "hidden"
objects that are not (transitively) referencing any non-hidden
objects.
C++ objects come in two versions.
a. Named objects that have been assigned a name through NameProvider.
b. Unnamed objects, that are potentially hidden if the build
configuration requires Oilpan to hide such names. Hidden objects have
their name set to NameProvider::kHiddenName.
The main challenge for the algorithm is to avoid blowing up the final
object graph with hidden nodes that do not carry information. For that
reason, the algorithm filters SCCs of only hidden objects, e.g.:
... -> (object) -> (object) -> (hidden) -> (hidden)
In this case the (hidden) objects are filtered from the graph. The
trickiest part is maintaining visibility state for objects referencing
other objects that are currently being processed.
Main algorithm idea (two passes):
1. First pass marks all non-hidden objects and those that transitively
reach non-hidden objects as visible. Details:
- Iterate over all objects.
- If object is non-hidden mark it as visible and also mark parent
as visible if needed.
- If object is hidden, traverse children as DFS to find non-hidden
objects. Post-order process the objects and mark those objects as
visible that have child nodes that are visible themselves.
- Maintain an epoch counter (StateStorage::state_count_) to allow
deferring the visibility decision to other objects in the same
SCC. This is similar to the "lowlink" value in Tarjan's algorithm
for SCC.
- After the first pass it is guaranteed that all deferred
visibility decisions can be resolved.
2. Second pass adds nodes and edges for all visible objects.
- Upon first checking the visibility state of an object, all deferred
visibility states are resolved.
For practical reasons, the recursion is transformed into an iteration.
We do not use plain Tarjan's algorithm to avoid another pass over
all nodes to create SCCs.
Follow ups:
1. Adding wrapper nodes for cpp objects that are wrappables for V8
wrappers.
2. Adding detachedness information.
Change-Id: I6e127d2c6d65e77defe08e39295a2594f463b962
Bug: chromium:1056170
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2467854
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70567}
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}
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}
Adds NameProvider to allow specifying names of objects. The
corresponding internal NameTrait is registered with the GCInfo object.
Use name infrastructure to provide a hint on encountering an unmarked
object in the marking verifier.
Bug: chromium:1056170
Change-Id: I95bb290660f5905500f861bd5cc85148a1b47184
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2454087
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@{#70400}
This is a first small step for implementing the memory64 proposal:
1. Add a feature flag.
2. Add the 0x04 and 0x05 limits flag for memory64.
3. Read memory limits as LEB-encoded u64 (instead of u32) if a memory64
limit flag was read.
4. Unify {MaximumFlag} and {MemoryFlag}, which was used inconsistently
before.
5. Add test for memory limits encoded with >5 bytes.
6. Move some macros from module-decoder-unittest.cc to wasm-macro-gen.h.
Note that still the same limits for the maximum number of pages applies
as before, i.e. you cannot specify a memory >4GB yet. But you can encode
that small number in >5 bytes.
R=manoskouk@chromium.org
Bug: v8:10949
Change-Id: I90a4f08426ae714a67440281785eb00cfc24a349
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2423712
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70110}
This is a reland of f25cb50a2f
Removed the problematic tests.
The problem with the test was that we try to pop from an empty segment.
GCC flags that as accessing beyond the array (i.e. index is uint16_t
equivalent of -1). Preceding the actual pop is a DCHECK that asserts
the segment isn't empty. In practice, since we have the DCHECK and
access to the segment is always via a Local, this shouldn't be a
problem.
Unfortunately, GCC flags the access regardless. The DCHECK goes through
a function pointer so GCC cannot determine that in our unittest the
DCHECK would crash if index is 0 and the access would not happen (The
indirection was added to allow for test DCHECK handlers that don't
crash, so we can't mark the function pointer as noreturn).
Drive-by: Segment::Pop and Segment::Push rely on the their Local
counterparts checking of emptiness/fullness, so we should always
access segments via Locals. Making the Segment ctor private.
Original change's description:
> Reland "cppgc, heap: Don't eagerly allocate worklist segments"
>
> This is a reland of c99147c65e
>
> Original change's description:
> > cppgc, heap: Don't eagerly allocate worklist segments
> >
> > Bug: chromium:1056170
> > Change-Id: I75a6b5f52bfe8dd71abc086e5d1e060759ad7fc0
> > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2391254
> > Commit-Queue: Omer Katz <omerkatz@chromium.org>
> > Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> > Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#69778}
>
> Bug: chromium:1056170
> Change-Id: I4633da065976a6b2710d2f23b946fd2af0e65c83
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2401425
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Commit-Queue: Omer Katz <omerkatz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69806}
Bug: chromium:1056170
Change-Id: I7a122d1a2d20cd4e7c824d249975b4d3df30e03e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2403251
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69829}
With conservative stack scanning enabled, a snapshot of the call stack
upon entry to GC will be used to determine part of the root-set. When
the collector walks the stack, it looks at each value and determines
whether it could be a potential on-heap object pointer. However, unlike
with Handles, these on-stack pointers aren't guaranteed to point to the
start of the object: the compiler may decide hide these pointers, and
create interior pointers in C++ frames which the GC doesn't know about.
The solution to this is to include an object start bitmap in the header
of each page. Each bit in the bitmap represents a word in the page
payload which is set when an object is allocated. This means that when
the collector finds an arbitrary potential pointer into the page, it can
walk backwards through the bitmap until it finds the relevant object's
base pointer. To prevent the bitmap becoming stale after compaction, it
is rebuilt during object sweeping.
This is experimental, and currently only works with inline allocation
disabled, and single generational collection.
Bug: v8:10614
Change-Id: I28ebd9562f58f335f8b3c2d1189cdf39feaa1f52
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2375195
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69615}
Schedule is simpler compared to the schedule in blink since it now
returns deadlines based on marked bytes instead of time.
If marking is ahead of schedule, return the minimum step size.
Otherwise, set step size to catch up to schedule (ignoring the time
passed while performing the step).
No more default initial step size (needed in blink since marking speed
was unknown).
If estimated schedule is exceeded (marking takes longer than 500ms), the
steps will try to mark all remaining objects but would still be capped
by the maximum step duration of 2ms.
Bug: chromium:1056170
Change-Id: I09857db161c621a12d064f9c8c21b646c34f9d71
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2375200
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@{#69602}
This patch introduces a new LocalIsolate and LocalFactory, which use
LocalHeap and replace OffThreadIsolate and OffThreadFactory. This allows
us to remove those classes, as well as the related OffThreadSpace,
OffThreadLargeObjectSpace, OffThreadHeap, and OffThreadTransferHandle.
OffThreadLogger becomes LocalLogger.
LocalHeap behaves more like Heap than OffThreadHeap did, so this allows
us to additionally remove the concept of "Finish" and "Publish" that the
OffThreadIsolate had, and allows us to internalize strings directly with
the newly-concurrent string table (where the implementation can now move
to FactoryBase).
This patch also removes the off-thread support from the deserializer
entirely, as well as removing the LocalIsolateWrapper which allowed
run-time distinction between Isolate and OffThreadIsolate. LocalHeap
doesn't support the reservation model used by the deserializer, and we
will likely move the deserializer to use LocalIsolate unconditionally
once we figure out the details of how to do this.
Bug: chromium:1011762
Change-Id: I1a1a0a72952b19a8a4c167c11a863c153a1252fc
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2315990
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69397}
This is a reland of b354e344fd
This CL adds 3 fixes:
* Unprotect code object before creating filler
* Allows AllocationObserver::Step to add more AllocationObservers
* Update limit in NewSpace::UpdateLinearAllocationArea
Original change's description:
> [heap] Refactor allocation observer in AllocationCounter
>
> Moves accounting of allocation observers into the AllocationCounter
> class. This CL removes top_on_previous_step_ for counters that are
> increased regularly in the slow path of the allocation functions.
>
> AdvanceAllocationObservers() informs the AllocationCounter about
> allocated bytes, InvokeAllocationObservers() needs to be invoked when
> an allocation step is reached. NextBytes() returns the number of bytes
> until the next AllocationObserver::Step needs to run.
>
> Bug: v8:10315
> Change-Id: I8b6eb8719ab032d44ee0614d2a0f2645bfce9df6
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2320650
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69170}
Bug: v8:10315
Change-Id: I89ab4d5069a234a293471f613dab16b47d8fff89
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2332805
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69216}
This reverts commit b354e344fd.
Reason for revert: Clusterfuzz found issues with this CL.
Original change's description:
> [heap] Refactor allocation observer in AllocationCounter
>
> Moves accounting of allocation observers into the AllocationCounter
> class. This CL removes top_on_previous_step_ for counters that are
> increased regularly in the slow path of the allocation functions.
>
> AdvanceAllocationObservers() informs the AllocationCounter about
> allocated bytes, InvokeAllocationObservers() needs to be invoked when
> an allocation step is reached. NextBytes() returns the number of bytes
> until the next AllocationObserver::Step needs to run.
>
> Bug: v8:10315
> Change-Id: I8b6eb8719ab032d44ee0614d2a0f2645bfce9df6
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2320650
> Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#69170}
TBR=ulan@chromium.org,dinfuehr@chromium.org
Change-Id: Icd713207bfb2085421fd82009be24a0211ae86da
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:10315
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2332667
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69187}
Moves accounting of allocation observers into the AllocationCounter
class. This CL removes top_on_previous_step_ for counters that are
increased regularly in the slow path of the allocation functions.
AdvanceAllocationObservers() informs the AllocationCounter about
allocated bytes, InvokeAllocationObservers() needs to be invoked when
an allocation step is reached. NextBytes() returns the number of bytes
until the next AllocationObserver::Step needs to run.
Bug: v8:10315
Change-Id: I8b6eb8719ab032d44ee0614d2a0f2645bfce9df6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2320650
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69170}
These are no longer tied to instruction-selector, so move them out into
their own unittests. We can then remove the *ForTesting methods.
Bug: v8:10696
Change-Id: I387cf38290d9602b011ee1d13ee5285ac660f208
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2326951
Reviewed-by: Bill Budge <bbudge@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69149}
PersistentHandlesScope works similar to the DeferredHandleScope, but
returns PersistentHandles instead of DeferredHandles on Detach().
Since PersistentHandlesScope takes over filled blocks from the
main thread local handle, remove the block_size_ field and use
kHandleBlockSize instead. This way all blocks have exactly the same size.
Bug: v8:10315
Change-Id: I295cad6f84852f87c55d95572905069443f5698c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2324254
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69138}
Adds support for register allocation within a block to the fast
register allocator. Also adds some unittests covering basic
register allocation. No support yet for spill slot allocation,
so functions that spill don't work yet.
BUG=v8:9684
Change-Id: I91d0fc0660d7b65f59235242fd5e3b1a7618d813
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2297467
Commit-Queue: Ross McIlroy <rmcilroy@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69045}
The following adds support for JSMember through the existing
GlobalHandles implementation also used for TracedReference.
In addition, JSMember now supports set, clear, copy, move, comparison
and interaction with Local.
Bug: chromium:1056170
Change-Id: Ia50218bcfe4c056b3533a5b14eea954ade1da243
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2310357
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@{#69028}
V8 already depends on cppgc_base which means that unittests does not
need to depend on cppgc_for_testing any longer.
Move the cppgc_for_testing dependency to the stand-alone
cppgc_unittests binary
Bug: v8:10674
Change-Id: I07bfe30901eb1683d2e0ee0189f73b5244884f27
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2310249
Auto-Submit: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68970}
This CL ports MarkingVerifier from blink.
The existing verifier checks only references on heap.
This new verifier checks references both on heap and on stack.
Bug: chromium:1056170
Change-Id: I083dcb0087125312cca34a2201015a9aecfe6ea4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2300484
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@{#68891}
- 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}
The interpreter is not used in production code any more, hence move it
from src/wasm to test/common/wasm.
It's still used in unit tests, cctests, and in fuzzers.
Because of this move, a few more methods had to be exported via
V8_EXPORT_PRIVATE.
R=ahaas@chromium.org, yangguo@chromium.org
Bug: v8:10389
Change-Id: If626b940a721146c596fd7df4faaea633e710272
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2257226
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68480}
This is a reland of 539f0ed23b
The reland fixes creating TimeDelta from double which requires
saturated_cast<>. Improvements to this constructions are tracked
in v8:10620.
Original change's description:
> cppgc,heap: Implement atomic unified heap GC
>
> Add v8::CppHeap as an implementation of a cppgc heap that
> integrates with V8's existing EmbedderHeapTracer API. The
> current implementation only supports non-incremental marking.
>
> Bug: chromium:1056170
> Change-Id: I4a09eb5ae57f5c7defe35eb3fe346627eb492473
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2245610
> Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
> Reviewed-by: Anton Bikineev <bikineev@chromium.org>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Omer Katz <omerkatz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#68374}
Bug: chromium:1056170,v8:10620
Change-Id: I39e15790e5cafe24da2a14d0bae6543391ebb536
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2248191
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@{#68387}
This adds the following things:
- age table for 4K regions;
- generational barrier for mixed 4K regions;
- unmarking for major collections;
- young generation flags.
Bug: chromium:1029379
Change-Id: Ief1229f0dac5f90c5f06d3168c8ffb4b7d1f1b53
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2246566
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68379}
