This is a step towards making JSObjectRef non-serialized.
Change JSObjectRef::RawFastPropertyAt to use a direct load with
relaxed semantics. Special handling of `uninitialized` sentinel values
is moved to the only use-site.
A new lock `boilerplate_migration_access` protects against concurrent
boilerplate migrations while we are iterating over properties.
Bug: v8:7790
Change-Id: Ic9de54ca16c1f3364d497a77058cfa33d48dd4a4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2928184
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75033}
In issue 11290, we disabled the propagation of EAL data out of
lookarounds, because it was incorrect for lookahead nodes in
loops. This caused performance regressions: for example,
`/^\P{Letter}+$/u` (matching only characters that are not in Unicode's
Letter category) uses negative lookahead when matching lone
surrogates, and became about 2x slower. I spent some time looking into
fixes, and this is what I've settled on.
Some background: the implementation of lookarounds in irregexp is
split between positive and negative lookaheads. (Lookbehinds aren't
relevant here, because backwards matches always have EAL=0.) Positive
lookaheads are wrapped in BEGIN_SUBMATCH and POSITIVE_SUBMATCH_SUCCESS
ActionNodes. BEGIN_SUBMATCH saves the current state.
POSITIVE_SUBMATCH_SUCCESS restores the necessary state (while leaving
any captures that occurred during the lookaround intact).
Negative lookaheads also begin with a BEGIN_SUBMATCH node, but follow
it with a NegativeLookaroundChoiceNode. This node has two successors:
a lookaround node, and a continue node. It only executes the continue
node if the lookaround node backtracks, which automatically restores
the previous state. Negative lookarounds also can't update captures.
This affects EAL calculations. It turns out that negative lookaheads
are already doing the right thing: EatsAtLeastPropagator only
propagates information from the continue node, ignoring the lookaround
node. The same is true for quick checks (see the comment in
RegExpLookaround:Builder::ForMatch). A BEGIN_SUBMATCH for a negative
lookahead can simply propagate the EAL data from its successor like
any other ActionNode, and everything works.
Positive lookaheads are harder. I tried saving a pointer to the
successor in BEGIN_SUBMATCH, but ran into problems in FillInBMInfo,
because the EAL value corresponded to the nodes after the lookahead,
but the analysis was still looking at the nodes inside. I fell back
to a more modest approach: split BEGIN_SUBMATCH in two, and propagate
EAL info for BEGIN_NEGATIVE_SUBMATCH while keeping the current
behaviour for BEGIN_POSITIVE_SUBMATCH. This fixes the performance
regression at hand.
Two potential approaches for fixing EAL for positive lookahead are:
1. Handling positive lookahead with its own dedicated choice node,
like NegativeLookaroundChoiceNode.
2. Adding an eats_at_least_inside_loop field to EatsAtLeastInfo,
which is <= eats_at_least_from_possibly_start, and using that
value in EatsAtLeastFromLoopEntry.
Both of those approaches are more complex than I want to tackle
right now, though.
Bug: v8:11844
Change-Id: I2a43509c2c21194b8c18f0a587fa21c194db76c2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2934858
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75031}
The test push stack boundary and too flaky (timeout) while
running machine with more memory.
Bug: v8:11845
Change-Id: I5b603f05270d224de71c735ece5dd65a27311c25
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2939082
Reviewed-by: Shu-yu Guo <syg@chromium.org>
Commit-Queue: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75030}
Due to the limits of ia32's calling convention, being able to
avoid construction of "Digits" objects (thanks to inlining)
helps a lot for microbenchmarks.
Fixed: chromium:1192133
Change-Id: I5676640d96a99dc6422f3946c608bcc93ef222ba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2947410
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Auto-Submit: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75028}
Add a new testing tier based on Liftoff. In this tier, the Liftoff
compiler takes an address to a counter, and decrements that counter at
every instruction. When the counter reaches 0, execution aborts.
R=clemensb@chromium.org
Bug: v8:11856
Change-Id: I20970e323ff19f7cb6ab6855377c678ca391421e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944440
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75022}
This CL updates Realm.eval() to also handle reading source code as a
JavaScript function or from a file. To distinguish between different
argument types, an additional options bag needs to be provided. If no
options bag is provided, the behavior defaults to the current one,
which is reading source code from a string.
Bug: v8:11525, v8:11706
Change-Id: I68238335eb91171041dca2c83db211c40dd68359
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944435
Reviewed-by: Marja Hölttä <marja@chromium.org>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Vicky Kontoura <vkont@google.com>
Cr-Commit-Position: refs/heads/master@{#75021}
Currently, the serializer and deserializer assume that all top-level
declarations to be serialized will be objects.
This CL removes this assumption.
Bug: v8:11525, v8:11706
Change-Id: I5acf5e7a3b73aba5ffc5b1d5eb9cb51b3804a4af
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2945178
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Marja Hölttä <marja@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Vicky Kontoura <vkont@google.com>
Cr-Commit-Position: refs/heads/master@{#75020}
This is needed for JSCallReducer.
Bug: chromium:1217562
Change-Id: I1f06040a74c393598c134301ba0cf04a46380107
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2945184
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Georg Neis <neis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75019}
Port f68e1be795
Original Commit Message:
Directly use the correct registers for calling the RecordWrite stubs
in sparkplug. To keep changes to existing builtins minimal there are
certain register requirements which are now made explicit in
WriteBarrierDescriptor::Verify.
R=cbruni@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N
Change-Id: Id01f936f96cf231dcfc599b4f2662124bc1a7744
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2945832
Reviewed-by: Junliang Yan <junyan@redhat.com>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/master@{#75018}
The initial CL is suspected to break the --predictable CI.
But looks like the CI is still crashing and also flaky after the
revert. So reland it again.
This is a reland of 59d58d722e
Original change's description:
> [csa] Remove InnerAllocate and replace with non-folded allocations
>
> This CL removes all uses of InnerAllocate (except memento allocations)
> and replace with non-folded allocations. The change is based on the
> fact that 1. Those InnerAllocates are not guarded by --allocation-folding
> flag. 2. Hopefully the MemoryOptimizer can handle the folding and no
> performance regression will happen.
>
> Two special versions of InnerAllocate is still kept:
> * One for memento allocations (renamed to InnerAllocateMemento).
> * One for AllocateUninitializedJSArrayWithElements (renamed to InnerAllocateElements).
>
> Change-Id: Ie77da6b2fba31b048241f7b7d927065305a01c27
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2873767
> Commit-Queue: Wenyu Zhao <wenyu.zhao@anu.edu.au>
> Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74899}
Change-Id: I540c3a6b6e3f7c70c048f8ad1e5f702287fb086b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2946667
Commit-Queue: Wenyu Zhao <wenyu.zhao@anu.edu.au>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75015}
Predictable does not contradict --wasm-tier-up any more, hence unskip
the tests.
R=ahaas@chromium.org
Bug: v8:11319, v8:11848
Change-Id: Iaefcf6c80e65d27c527aa1a45b054ace1d85fe39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2945171
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75013}
Heaps in V8 start with a large limit that is shrunk upon young
generation GCs, based on some liveness estimate. This provides best
throughput during startup while at the same time finding a reasonable
first limit.
For C++ (embedder memory) there is no estimate which is why it was
piggy-backing on V8. This breaks in scenarios where no JS memory is
allocated.
In this fix we start a memory reducer after embedder memory has hit
the activation threshold if no GC happened so far. As soon as a single
Scavenger has happened, we leave it up to the JS estimate to figure
out a limit. Memory reducing GCs will then find a regular limit based
on the initial live size.
Drive-by: Give embedders the same activiation threshold of 8MB as JS.
Bug: chromium:1217076
Change-Id: I8469696002ac2af8d75d6b47def062d2608387a1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944935
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75012}
This is a reland of 79d63a5ef3. Some fixes
landed already, and two tests need to be skipped now (one with a tracking
bug).
Original change's description:
> [wasm] Remove all implications from --predictable
>
> In predictable mode, we want to execute the same code as otherwise,
> modulo timing. Hence remove any implications which change behaviour
> (like tier-up or asynchronous compilation).
> Note that --predictable is a debugging flag, so the configurations does
> not need to "make sense" in production.
>
> R=ahaas@chromium.org
>
> Bug: v8:11848
> Change-Id: If74fbacadeb087d977922c41f33fd18738b50ded
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2940898
> Commit-Queue: Clemens Backes <clemensb@chromium.org>
> Reviewed-by: Andreas Haas <ahaas@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#74973}
Bug: v8:11848
Change-Id: I3564e4351d6545bb9643d1ae44722eb2606b8961
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944936
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75009}
- Scale svg flamechart directly instead of rerendering
- Convert markers to SVG as well
- Fix scroll position after zooming
- Support tooltips for flamechart
Change-Id: I01c966d2705989cf45a91c64aa4302a8de035414
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944894
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75008}
The predictable platform only executed background tasks if at least one
foreground task was executed. Async compilation in Wasm only spawns a
background task though, so that one could be missed.
This CL fixes the loop to also execute background tasks if no foreground
task was executed.
R=ahaas@chromium.org
Bug: v8:11848
Change-Id: Ia0b32427c24a79d5710c784b98528bf431471528
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944833
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75007}
Changes:
- Add struct.new_with_rtt as a new WasmInitExpr. Parse it in
consume_init_expr(). Add it to
InstanceBuilder::EvaluateInitExpression().
- Change WasmInitExpr::operand_ to vector operands_.
- In consume_init_expr(), use parsed over hard-coded opcode length.
- Improve WasmStruct::WasmStructPrint slightly.
- Add Factory::NewWasmStruct().
- Add WasmValue::CopyToWithSystemEndianness.
- In wasm-module-builder.js, generalize emit_init_expr for expressions
with operands. Add missing init. expression types.
- Add tests.
Bug: v8:7748
Change-Id: Ica12378d202730aff1b57c7d4240aa00ef124f8e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2940893
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75006}
This reverts commit febfbb21b9.
Reason for revert: Introduced new bugs:
https://ci.chromium.org/ui/p/v8/builders/ci/V8%20Mac64%20-%20debug/34472/overview
Original change's description:
> [sparkplug] Adjust compare and jump function in sparkplug
>
> Mips and risc-v do not have the flag register and can not decide
> whether to jump through flags in JumpIf();
>
> Therefor, we merge the comparison with the jump;
>
> Bug: v8:11803
>
> Change-Id: If53752da93b97e8ff65affdfe99e5de8e1a1493f
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2921034
> Auto-Submit: Liu yu <liuyu@loongson.cn>
> Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
> Reviewed-by: Leszek Swirski <leszeks@chromium.org>
> Reviewed-by: Toon Verwaest <verwaest@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#75001}
Bug: v8:11803
Change-Id: Ic982564ccdef9a07bf3a5fb4745a11cfa178cc0e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2946818
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/master@{#75005}
This commit adds a TryGetCurrent() method to the v8::Isolate class.
The motivation for adding this method this is that in Node.js we've run
into situations where we need to check if there is a current
Isolate and we are using GetCurrent() for this. The issue is that for a
debug build of Node.js, the debug check in GetCurrent() will cause a
failure.
The suggestion in this changeset is to allow getting the current
Isolate, or null if one does not exist, without any checks.
Change-Id: I01676e4bcdbe86da0496f5df1982d14eb1c9ebf8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2910630
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75004}
Jobs were still being posted on the underlying default platform, which
caused concurrent execution. By directly returning a
{NewDefaultJobHandle} with a pointer to the {PredictablePlatform}, we
force execution of all posted tasks via that platform.
R=ahaas@chromium.org, cbruni@chromium.org
Bug: v8:11848
Change-Id: Ie10519583341b427776ca428f85641e96f821367
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944808
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75002}
Mips and risc-v do not have the flag register and can not decide
whether to jump through flags in JumpIf();
Therefor, we merge the comparison with the jump;
Bug: v8:11803
Change-Id: If53752da93b97e8ff65affdfe99e5de8e1a1493f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2921034
Auto-Submit: Liu yu <liuyu@loongson.cn>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75001}
The flag had no effect and was removed from fuzzilli instructions here:
f31bfb7b5a
No-Try: true
Change-Id: If28e79fdf469a4cb665a83793c9fef8c6c2a8232
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944431
Auto-Submit: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75000}
Directly use the correct registers for calling the RecordWrite stubs
in sparkplug. To keep changes to existing builtins minimal there are
certain register requirements which are now made explicit in
WriteBarrierDescriptor::Verify.
Bug: v8:11420
Change-Id: I3a0c500fbe26f82ee2243a61dbf574fd31656982
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2910313
Reviewed-by: Santiago Aboy Solanes <solanes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74998}
- Add new Builtin enum
- Move Builtins::Name:kXXX to Builtin::kXXX
- Update existing code
Follow CLs will unify the mix of using int builtin-ids and
Builtins::Name to only use the new Builtin enum and changing it to
an enum class.
Change-Id: Ib39aa45a25696acdf147f46392901b1e051deaa4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2905592
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Michael Stanton <mvstanton@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74995}
This will allow Fuchsia tests to be run on v8 CI
Bug: v8:11843, chromium:934932
Change-Id: I516329d8f29d9c94d46aa010fa729fa3ca0993ee
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2935024
Commit-Queue: Chong Gu <chonggu@google.com>
Auto-Submit: Chong Gu <chonggu@google.com>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74993}
The flag --trace-ignition-dispatches has been broken for a long time,
since it was not designed to work with bytecode handlers that are
generated ahead of time by mksnapshot. This splits the existing
--trace-ignition-dispatches logic into two separate parts:
1. A gn argument which instructs mksnapshot to include dispatch counting
in the bytecode handlers, and ensures that the Interpreter allocates
the array of counters, and
2. A runtime flag which enables the ignition-statistics extension which
implements the JS-accessible function getIgnitionDispatchCounters().
Change-Id: I89323425697f5641451f67b9ddcc0303b8ca209f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2937564
Reviewed-by: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#74992}
xmm0 and xmm1 are used to save/restore values in asm builtins, but they
were not saved before calling RecordWrite, which calls C++ code.
Instead of passing SaveFPRegsMode::kSave to RecordWriteField, which
would save/restore all FP-regs, this CL explicitly saves/restores the
FP-regs we rely on beyond the C-Call.
Bug: chromium:1216295
Change-Id: Ifcc7ce4e8819303ffb79576a88304df2e3a6cc4c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944427
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74991}
Left-trimming only works when there is a single reference to the
backing store from the JS object. Main thread handles are an exception
to this rule because it is not feasible to ensure that no such
leftover handles may store such stale pointers.
FixStaleLeftTrimmedHandlesVisitor clears such references
in main thread handles, such that the GC never tries to visit them. This
CL renames this class to ClearStaleLeftTrimmedHandlesVisitor to
emphasize that such slots are cleared rather than "fixed up" to point
to the new object start.
Previously ClearStaleLeftTrimmedHandlesVisitor was used for local
and persistent handles as well. Starting with this CL, stale references
to left-trimmed objects are only allowed in main thread handles.
https://crrev.com/c/2928502 enabled us to be more restrictive here.
Change-Id: If4db0630f1df2d6c3fe5f242bf866c57a8ae2969
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944807
Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74989}
- Introduce proper TickLogEntry and use a separate Timeline object
- Update the main rendering to use SVG for speed
- Separate custom-elements: timeline-track-map and timeline-track-tick
- Revamp flame-chart drawing
- Enable map-transitions overlay
- Use mouse position to infer current log-entry instead of individual
event handlers
- Fix first timelineLegend column header
- Fixing scrollbar-color for FireFox
Change-Id: I7c53c13366b3e4614b1c5592dfaa69d0654a3b5f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944430
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Reviewed-by: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74987}
Use new Script.prototype.update method to set the url and the script
source.
Bug: v8:11850
Change-Id: I555d4d0158cdacb7cb42efa385371454542fc2f3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2944438
Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74985}
We have recursive calls such ThinStrings where we go String::Get into
ThinString::Get into String::Get again for the internalized string. If
we need to, we would acquire the StringAccessGuard in the first
String::Get and it wouldn't be needed to be re-acquired for the second
String::Get. Trying to re-acquire it would in fact be an error since we
are already holding the lock.
The code, however, didn't know if we acquired it or not. It was working
correctly due to the way the methods were defined and called. By passing
down the access guard through the Get() calls we make this interaction
explicit.
Also add some thin string tests to test the interaction.
Bug: v8:7790
Change-Id: I1181edec1e802cb754c4d1d1ac268577257b92f3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2936598
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74984}
