This patch removes TracingCategoryObserver API and moves the creation of
observer inside platform initialization, by assuming that either
Platform::AddTraceStateObserver is implemented correctly to add observer to
tracing controller that implemented by embedders, or default tracing controller
has already been set up and attached to platform before
v8::V8::InitializePlatform is called.
BUG=v8:5590
Review-Url: https://codereview.chromium.org/2471583004
Cr-Commit-Position: refs/heads/master@{#40739}
We only need included categories list, excluded categories list will only work
if we use regular expression in categories list, which is not supported in V8.
TBR=jochen@chromium.org
Review-Url: https://codereview.chromium.org/2462143002
Cr-Commit-Position: refs/heads/master@{#40681}
This patch implements TracingCategoryObserver to set global flag when a V8
specific category is enabled. Previously, we set a global flag each time when we
encounter a top level trace event, and use it as a global check. With this
patch, we can set a group of flags when tracing is enabled; besides, we make
V8 tracing feature use V8 flags instead of defining its own flag in a messy way.
With this patch, whatever V8 flag we want to imply in tracing, we define another
integer flag, and the original V8 flag will set it to 0x01 when passing by
commandline, tracing will set it to 0x10 when we start tracing and reset the bit
when we stop tracing.
Review-Url: https://codereview.chromium.org/2436273002
Cr-Commit-Position: refs/heads/master@{#40659}
This is useful for things that don't ever change, but we don't want to
eagerly compute the result.
Doing this from the embedder is difficult, using DefineOwnProperty would
read the property to get the property descriptor, creating an endless
recursion.
R=verwaest@chromium.org,haraken@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2449783006
Cr-Commit-Position: refs/heads/master@{#40648}
Since the public API for deserialization is now just DeserializeOrCompile,
we can trickle down the wire bytes to the deserialization logic, and
avoid the need for duplicating the wire bytes when serializing.
BUG=chromium:657316
Review-Url: https://chromiumcodereview.appspot.com/2433273002
Cr-Commit-Position: refs/heads/master@{#40516}
Added a size constraint to the configuration to limit the segment pool.
This will likely fix the memory alerts from small android devices.
BUG=chromium:655129
Review-Url: https://chromiumcodereview.appspot.com/2424393002
Cr-Commit-Position: refs/heads/master@{#40476}
This CL also adds separate runtime call stats buckets for data handlers.
BUG=
Review-Url: https://codereview.chromium.org/2419513002
Cr-Commit-Position: refs/heads/master@{#40281}
This incorporates recent feedback:
- simpler deserialization API by dropping the std::unique_ptr.
The only purpose there was communicating to the caller that they
own the buffer, and that the deserializer won't delete it. The new
design communicates that through a naming choice.
- renamed *UncompiledBytes to *WasmWireBytes
BUG=
Review-Url: https://codereview.chromium.org/2411263004
Cr-Commit-Position: refs/heads/master@{#40238}
The state sampling was implemented in chrome, we had an interface for it
V8 but it was not implemented yet.
The chrome version version has been removed in
https://codereview.chromium.org/2406703002/
Therefore following up with its removal in V8 as well.
This CL can land independent of the Chromium related CL.
R=primiano@chromium.org,alph@chromium.org
Review-Url: https://codereview.chromium.org/2410523002
Cr-Commit-Position: refs/heads/master@{#40232}
This is a re-land of https://codereview.chromium.org/2393303002/ with
an additional call to DisposeModuleEmbedderData() added to fix lsan failures.
Unifies the approaches used for storing the specifier -> module mapping
and the module -> directory mapping, using std::unordered_maps for both
and storing them per-Context.
This requires adding a method to the v8::Module API to get a hash code
for a Module, but allows slimming down the API in return: gone are
SetEmbedderData/GetEmbedderData, along with the fourth argument
to ResolveModuleCallback.
Besides a simpler API, this allows d8 to get closer to the HTML loader,
which requires each Realm to have a persistent module map (though this
capability is not yet exercised by any tests).
BUG=v8:1569
TBR=neis@chromium.org,jochen@chromium.org
Review-Url: https://codereview.chromium.org/2405313002
Cr-Commit-Position: refs/heads/master@{#40186}
Reason for revert:
Fails under LeakSanitizer on auto-roll fyi bot:
https://build.chromium.org/p/client.v8.fyi/builders/Auto-roll%20-%20release%20process/builds/49447
Original issue's description:
> [modules] Store Module metadata in per-Context EmbedderData
>
> Unifies the approaches used for storing the specifier -> module mapping
> and the module -> directory mapping, using std::unordered_maps for both
> and storing them per-Context.
>
> This requires adding a method to the v8::Module API to get a hash code
> for a Module, but allows slimming down the API in return: gone are
> SetEmbedderData/GetEmbedderData, along with the fourth argument
> to ResolveModuleCallback.
>
> Besides a simpler API, this allows d8 to get closer to the HTML loader,
> which requires each Realm to have a persistent module map (though this
> capability is not yet exercised by any tests).
>
> BUG=v8:1569
>
> Committed: https://crrev.com/9cf8fce74cf6e7afd6aea3f3545f6bb61572f277
> Cr-Commit-Position: refs/heads/master@{#40133}
TBR=jochen@chromium.org,neis@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2406973003
Cr-Commit-Position: refs/heads/master@{#40145}
Unifies the approaches used for storing the specifier -> module mapping
and the module -> directory mapping, using std::unordered_maps for both
and storing them per-Context.
This requires adding a method to the v8::Module API to get a hash code
for a Module, but allows slimming down the API in return: gone are
SetEmbedderData/GetEmbedderData, along with the fourth argument
to ResolveModuleCallback.
Besides a simpler API, this allows d8 to get closer to the HTML loader,
which requires each Realm to have a persistent module map (though this
capability is not yet exercised by any tests).
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2393303002
Cr-Commit-Position: refs/heads/master@{#40133}
Updated the deserialization API to avoid copying uncompiled
bytes.
BUG=
Review-Url: https://codereview.chromium.org/2404673002
Cr-Commit-Position: refs/heads/master@{#40108}
One step closer to the informally-agreed upon specification
that structured cloning will always succeed, meaning, if
we fail to deserialize (e.g. because version mismatch in
serialized format and v8 version), we recompile.
As part of this work, the deserializer will need to become
more resilient to invalid input data, and fail graciously
rather than CHECK-ing. This CL addresses some of that,
sufficient to unblock the current serialization tests.
Subsequent CLs will add more testing and the appropriate
fixes.
BUG=639090
Review-Url: https://codereview.chromium.org/2395793003
Cr-Commit-Position: refs/heads/master@{#40058}
A new V8 API object v8::TracingCpuProfiler is introduced.
Client can create it on an isolate to enable JS CPU profiles collected
during tracing session.
Once the v8.cpu_profile2 tracing category is enabled the profiler emits
CpuProfile and CpuProfileChunk events with the profile data.
BUG=chromium:406277
Review-Url: https://codereview.chromium.org/2396733002
Cr-Commit-Position: refs/heads/master@{#40054}
Tracing CPU profiler allows V8 to automatically collect CPU profile when tracing
is started with category v8.cpu_profile2 enabled.
BUG=chromium:406277
Review-Url: https://codereview.chromium.org/2378143003
Cr-Commit-Position: refs/heads/master@{#39855}
This cl introduces reporter to the embedder heap tracer. Heap tracer uses
reporter to report reachable objects from embedder heap. This refactoring is a
step towards being able to take heap snapshots with wrapper tracing.
LOG=no
BUG=468240
Review-Url: https://codereview.chromium.org/2371733002
Cr-Commit-Position: refs/heads/master@{#39824}
Add documentation for Has(), HasOwnProperty(), and HasRealNamedProperty()
that points out their differences and links to the other functions.
BUG=v8:5433
Review-Url: https://codereview.chromium.org/2365403003
Cr-Commit-Position: refs/heads/master@{#39818}
DevTools wants to be able to detect async functions in order to print
their synopsis better in stack traces and tooltips. This patch provides a
simple method to do the check.
BUG=v8:4483
Review-Url: https://codereview.chromium.org/2365833002
Cr-Commit-Position: refs/heads/master@{#39687}
- Add a new container object to store the data required for
PromiseResolveThenableJob.
- Create a new runtime function to enqueue the microtask event with
the required data.
This patches causes a 4% regression in the bluebird benchmark.
BUG=v8:5343
Review-Url: https://codereview.chromium.org/2314903004
Cr-Commit-Position: refs/heads/master@{#39571}
This patch gives the ability for the embedder to ask for the
module requests of a module, and to pass a ResolveCallback
into Module::Instantiate().
In d8, I've implemented a simple module_map that's used
along with this API to allow loading, compiling, instantiating,
and evaluating a whole tree of modules.
No path resolution is yet implemented, meaning that all
import paths are relative to whatever directory d8 runs
in. And no imports are linked to the exports of the
requested module.
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2351113004
Cr-Commit-Position: refs/heads/master@{#39569}
Reason for revert:
Unblocking roll
Original issue's description:
> [d8] Fix the shared-library build
>
> This commit ensures that the d8 shared library build uses the same logic as
> the standard static build by exporting relevant functions and classes.
>
> BUG=chromium:646337
>
> Committed: https://crrev.com/2c10ca8086a4d595ecf9aa843d2031b068470d65
> Cr-Commit-Position: refs/heads/master@{#39503}
TBR=jochen@chromium.org,vogelheim@chromium.org,bmeurer@chromium.org,titzer@chromium.org,jgruber@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:646337
Review-Url: https://codereview.chromium.org/2356703003
Cr-Commit-Position: refs/heads/master@{#39526}
Introduce TraceStateObserver interface along with add/remove
methods to the platform.
BUG=chromium:406277
Review-Url: https://codereview.chromium.org/2344893005
Cr-Commit-Position: refs/heads/master@{#39513}
This commit ensures that the d8 shared library build uses the same logic as
the standard static build by exporting relevant functions and classes.
BUG=chromium:646337
Review-Url: https://codereview.chromium.org/2342563002
Cr-Commit-Position: refs/heads/master@{#39503}
Rename JSModule to Module and make it a Struct rather than a JSObject. We will
later add a separate JSModuleNamespace object to implement the 'import * as foo'
syntax.
BUG=v8:1569
Review-Url: https://codereview.chromium.org/2345823002
Cr-Commit-Position: refs/heads/master@{#39477}
This exposes an interface for the embedder to provide a delegate which can
serialize or deserialize embedder-specific objects, like Blink's DOM wrappers.
BUG=chromium:148757
Review-Url: https://codereview.chromium.org/2327653002
Cr-Commit-Position: refs/heads/master@{#39422}
GetFunctionNameStr and GetScriptResourceNameStr can be called from a thread
other than isolate VM thread unlike their conterparts GetFunctionName
and GetScriptResourceName.
BUG=406277
Review-Url: https://codereview.chromium.org/2328673003
Cr-Commit-Position: refs/heads/master@{#39313}
The existing PropertyQueryCallback intercepts getOwnPropertyDescriptor, but
it returns only value and attributes, not the accessors. This
PropertyDescriptorCallback returns a descriptor similar to Ecma-262 6.2.4.
You can either set a PropertyQueryCallback or a PropertyDescriptorCallback,
but not both. When you set a callback for DefineProperty(), you can set a
PropertyDescriptorCallback but not a PropertyQueryCallback.
BUG=v8:5359
Review-Url: https://codereview.chromium.org/2311873002
Cr-Commit-Position: refs/heads/master@{#39279}
- inspector becomes a dependency of v8_base;
- generated public protocol files are placed to gen/v8/include/inspector/<Domain.h>;
- added v8_enable_inspector_override to be used in embedders (gn only);
- combined public headers into v8-inspector.h and v8-inspector-protocol.h.
BUG=chromium:635948
Review-Url: https://codereview.chromium.org/2292053003
Cr-Commit-Position: refs/heads/master@{#39226}
This restores the contract that all API methods that return Maybe<T> or
MaybeLocal<T> always throw an exception when they return nothing.
Since v8::ValueDeserializer::ReadHeader can now throw exceptions, it
needs a Local<Context> parameter so that it can set up execution state
(entering the context, etc.). The old method has been marked for
deprecation, but since this API is experimental I intend to remove it
as soon as I've removed the use from Blink.
value-serializer-unittest has been updated to expect an exception in
all decode failure cases.
BUG=chromium:148757,chromium:641964
Review-Url: https://codereview.chromium.org/2308053002
Cr-Commit-Position: refs/heads/master@{#39188}
With the Indexed/GenericNamedPropertyDefinerCallback it is possible to intercept Object.defineProperty() calls.
Requests that call JSReceiver::OrdinaryDefineOwnProperty() internally, also trigger the interceptor. This includes Object.freeze(), Object.preventExtensions(), and Object.seal().
As without this patch, the query interceptor triggers on
defineProperty, unless the definer callback
intercepts the request.
As without this patch, the query interceptor triggers on defineProperty, unless the definer callback intercepts the request.
BUG=
Committed: https://crrev.com/b9d985975cf3bab0ded0cec9fafd3799f9bde29a
Review-Url: https://codereview.chromium.org/2272383002
Cr-Original-Commit-Position: refs/heads/master@{#39094}
Cr-Commit-Position: refs/heads/master@{#39122}
Reason for revert:
Breaks cctest/test-api-interceptors/QueryInterceptor on the waterfall
Original issue's description:
> [api] Add interceptor for defineProperty().
>
> With the Indexed/GenericNamedPropertyDefinerCallback it is possible to intercept Object.defineProperty() calls.
>
> Requests that call JSReceiver::OrdinaryDefineOwnProperty() internally, also trigger the interceptor. This includes Object.freeze(), Object.preventExtensions(), and Object.seal().
>
> BUG=
>
> Committed: https://crrev.com/b9d985975cf3bab0ded0cec9fafd3799f9bde29a
> Cr-Commit-Position: refs/heads/master@{#39094}
TBR=jochen@chromium.org,franzih@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review-Url: https://codereview.chromium.org/2303533004
Cr-Commit-Position: refs/heads/master@{#39095}
With the Indexed/GenericNamedPropertyDefinerCallback it is possible to intercept Object.defineProperty() calls.
Requests that call JSReceiver::OrdinaryDefineOwnProperty() internally, also trigger the interceptor. This includes Object.freeze(), Object.preventExtensions(), and Object.seal().
BUG=
Review-Url: https://codereview.chromium.org/2272383002
Cr-Commit-Position: refs/heads/master@{#39094}
Also add tests that document the behavior of the PropertyQueryCallback.
BUG=v8:5260
Review-Url: https://codereview.chromium.org/2286323002
Cr-Commit-Position: refs/heads/master@{#39090}
The comment for the Proxy::New functions seems inaccurate and is
currently identical to Map::New:
3090 /**
3091 * Creates a new empty Map.
3092 */
3093 static Local<Map> New(Isolate* isolate);
This commit updates the comment to describe that it creates a Proxy and
not a Map.
BUG=
Review-Url: https://codereview.chromium.org/2176063002
Cr-Commit-Position: refs/heads/master@{#39002}
V8 can use this metter to better estimate the amount of work that is still to be
done by the embedder. Supposed to be used to decide whether incremental marking
should be finalized or not.
BUG=chromium:468240
R=ulan@chromium.org
Review-Url: https://codereview.chromium.org/2291613002
Cr-Commit-Position: refs/heads/master@{#38985}
Add comments to make it easier to browse the HTML documentation generated with Doxygen.
BUG=v8:5260
Review-Url: https://codereview.chromium.org/2290553003
Cr-Commit-Position: refs/heads/master@{#38982}
The embedder is expected to arrange for the array buffer contents to be
transferred into a v8::ArrayBuffer in the receiving context (generally by
assuming ownership of the externalized backing store).
BUG=chromium:148757
Review-Url: https://codereview.chromium.org/2275033003
Cr-Commit-Position: refs/heads/master@{#38948}
Suitably scary warnings attached, as this will yet evolve (notably to handle
host objects, which are not currently handled).
Unit tests adjusted to use the public version of ValueSerializer, eliminating
any need they have to access v8::internal.
With this, Blink can begin using this code experimentally behind a flag as it
develops.
BUG=chromium:148757
Review-Url: https://codereview.chromium.org/2274693002
Cr-Commit-Position: refs/heads/master@{#38915}
According to our style guide on Copyable and Movable Types,
copy/move operators should be disabled using = delete in the public: section.
Use consistent style for disabling new and delete.
BUG=
Review-Url: https://codereview.chromium.org/2276063002
Cr-Commit-Position: refs/heads/master@{#38880}
According to our style guide on Copyable and Movable Types,
copy/move operators should be disabled using = delete in the public: section,
not in the private: section.
BUG=
Review-Url: https://codereview.chromium.org/2272063002
Cr-Commit-Position: refs/heads/master@{#38879}
According to our style guide on Copyable and Movable Types,
copy/move operators should be disabled in the public: section, not
in the private: section.
BUG=
Review-Url: https://codereview.chromium.org/2278573002
Cr-Commit-Position: refs/heads/master@{#38872}
This flag was shipped on in 52, so it's due for removal. The patch includes
removing the deprecated and unused-in-Blink API Promise::Chain, and many
test updates.
R=adamk@chromium.org
BUG=v8:4633
Review-Url: https://codereview.chromium.org/2267033002
Cr-Commit-Position: refs/heads/master@{#38804}
Reason for revert:
Tanks octane
Original issue's description:
> [heap] Improve size profiling for ArrayBuffer tracking
>
> Eagerly account for retained sizes during ArrayBuffer tracking. Following up on this,
> we can now do Scavenges if the amount of memory retained from new space is too large.
>
> BUG=chromium:621829
> R=jochen@chromium.org,hpayer@chromium.org
>
> Committed: https://crrev.com/28e13bd6a75c9467dae43043e7b741a1387d5252
> Cr-Commit-Position: refs/heads/master@{#38731}
TBR=jochen@chromium.org,hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:621829
Review-Url: https://codereview.chromium.org/2261513003
Cr-Commit-Position: refs/heads/master@{#38739}
Eagerly account for retained sizes during ArrayBuffer tracking. Following up on this,
we can now do Scavenges if the amount of memory retained from new space is too large.
BUG=chromium:621829
R=jochen@chromium.org,hpayer@chromium.org
Review-Url: https://codereview.chromium.org/2210263002
Cr-Commit-Position: refs/heads/master@{#38731}
Reason for revert:
Performance regressions in Gameboy, Life, CodeLoad and others. See crbug.com/638210.
Original issue's description:
> Refactor data structures for simple stack traces
>
> Simple stack traces are captured through Isolate::CaptureSimpleStackTrace.
> Captured frames are stored in a FixedArray, which in turn is stored as a
> property (using a private symbol) on the error object itself. Actual formatting
> of the textual stack trace is done lazily when the user reads the stack
> property of the error object.
>
> This would involve many conversions back and forth between index-encoded raw
> data (receiver, function, offset and code), JS CallSite objects, and C++
> CallSite objects.
>
> This commit refactors the C++ CallSite class into a Struct class called
> StackTraceFrame, which is the new single point of truth frame information.
> Isolate::CaptureSimpleStackTrace stores an array of StackTraceFrames, and JS
> CallSite objects (now created only when the user specifies custom stack trace
> formatting through Error.prepareStackTrace) internally only store a reference
> to a StackTraceFrame.
>
> BUG=
>
> Committed: https://crrev.com/b4c1aefb9c369f1a33a6ca94a5de9b06ea4bf5c4
> Cr-Commit-Position: refs/heads/master@{#38645}
TBR=yangguo@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=
Review-Url: https://codereview.chromium.org/2252783007
Cr-Commit-Position: refs/heads/master@{#38700}
Simple stack traces are captured through Isolate::CaptureSimpleStackTrace.
Captured frames are stored in a FixedArray, which in turn is stored as a
property (using a private symbol) on the error object itself. Actual formatting
of the textual stack trace is done lazily when the user reads the stack
property of the error object.
This would involve many conversions back and forth between index-encoded raw
data (receiver, function, offset and code), JS CallSite objects, and C++
CallSite objects.
This commit refactors the C++ CallSite class into a Struct class called
StackTraceFrame, which is the new single point of truth frame information.
Isolate::CaptureSimpleStackTrace stores an array of StackTraceFrames, and JS
CallSite objects (now created only when the user specifies custom stack trace
formatting through Error.prepareStackTrace) internally only store a reference
to a StackTraceFrame.
BUG=
Review-Url: https://codereview.chromium.org/2230953002
Cr-Commit-Position: refs/heads/master@{#38645}
A test exercising the public APIs for wasm serialization and
simulates the serialization scenario - serialize in one isolate, deserialize
in another.
BUG=v8:5072
Review-Url: https://codereview.chromium.org/2249973002
Cr-Commit-Position: refs/heads/master@{#38644}
This patch is based on alph's CL https://codereview.chromium.org/2128613004/.
This patch makes GetStackSample propogate the register state when using
simulator helper, and adds argument to avoid using register state from simulator
when pass the native register state.
BUG=v8:4789
LOG=N
Review-Url: https://codereview.chromium.org/2189513002
Cr-Commit-Position: refs/heads/master@{#38554}
LoadInternalField performs some redundant checks in the context of
fast accessors.
This improves the speedup from 20% to 60% for next/previousSibling in
the Dromaeo DOM traversal benchmarks.
BUG=chromium:508898
Review-Url: https://codereview.chromium.org/2186593002
Cr-Commit-Position: refs/heads/master@{#38535}
We only need these external v8 APIs to expose serialization externally,
so bypassed having an internal layer for now.
BUG=v8:5072
Review-Url: https://codereview.chromium.org/2228073002
Cr-Commit-Position: refs/heads/master@{#38516}
Drive-by-fix: mark isolates as const in stack-allocated scopes
BUG=chromium:630217
Review-Url: https://codereview.chromium.org/2220993003
Cr-Commit-Position: refs/heads/master@{#38496}
This new API function allows for setting several internal fields at once.
By avoiding crossing the API each time for setting an internal property we
can speed up the wrapper creation which has to set two fields for every new
object.
BUG=chromium:630217
Review-Url: https://codereview.chromium.org/2185963002
Cr-Commit-Position: refs/heads/master@{#38299}
The client can use scriptId + lineNumber + columnNumber
to uniquelly identify the call site.
Review-Url: https://codereview.chromium.org/2199003003
Cr-Commit-Position: refs/heads/master@{#38236}
Add deps file allowing libplatform.h to include v8-tracing.h.
Additionally removes redundant include/ that was causing build errors
for node-lkgr.
BUG=
Review-Url: https://codereview.chromium.org/2195403002
Cr-Commit-Position: refs/heads/master@{#38217}
Reason for revert:
Revert this CL due to V8 Arm Builder failure and V8 Mips Builder failure.
https://build.chromium.org/p/client.v8.ports/builders/V8%20Arm%20-%20builder/builds/2456https://build.chromium.org/p/client.v8.ports/builders/V8%20Mips%20-%20builder/builds/2506
Original issue's description:
> [Tracing] V8 Tracing Controller
>
> V8 has had a trace event macro interface for while, but without a tracing
> controller a standalone V8 would be unable to collect traces.
>
> This CL introduces a complete Tracing Controller system for V8.
> It is fully function except that it does not yet store trace event args.
>
> This CL has a few components,
> The tracing controller itself, contributed by the author of this CL
> The Trace config (including the parser), contributed by lpy@
> The Trace Object, Trace Writer, and Trace Buffer are all contributed by rksang@
>
> BUG=v8:4561
> LOG=N
>
> Committed: https://crrev.com/3d598452679ce208ad9b2f48e0fb3fae352ce375
> Cr-Commit-Position: refs/heads/master@{#38073}
TBR=jochen@chromium.org,mattloring@google.com,rskang@google.com,yangguo@chromium.org,fmeawad@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4561
Review-Url: https://codereview.chromium.org/2183943002
Cr-Commit-Position: refs/heads/master@{#38074}
V8 has had a trace event macro interface for while, but without a tracing
controller a standalone V8 would be unable to collect traces.
This CL introduces a complete Tracing Controller system for V8.
It is fully function except that it does not yet store trace event args.
This CL has a few components,
The tracing controller itself, contributed by the author of this CL
The Trace config (including the parser), contributed by lpy@
The Trace Object, Trace Writer, and Trace Buffer are all contributed by rksang@
BUG=v8:4561
LOG=N
Review-Url: https://codereview.chromium.org/2137013006
Cr-Commit-Position: refs/heads/master@{#38073}
Introduce a proper CodeStubAssembler::BranchIfToBooleanIsTrue helper
method, that branches to if_true/if_false labels depending on whether
the value that is passed would yield true or false when fed to
ToBoolean. Use this helper to implement the bytecode handlers w/o having
to materialize the temporary booleans and essentially branching twice.
The CodeStubAssembler::BranchIfToBooleanIsTrue helper favors the most
likely case of a Boolean constant now.
Also migrate the ToBooleanStub to a ToBoolean TurboFan builtin, that
also uses the helper method under the hood.
Remove the now obsolete Oddball::to_boolean field.
R=hpayer@chromium.org, rmcilroy@chromium.org, yangguo@chromium.org
Review-Url: https://codereview.chromium.org/2151163002
Cr-Commit-Position: refs/heads/master@{#37849}
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
BUG=chromium:541703
R=verwaest@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
Review-Url: https://codereview.chromium.org/2155503004
Cr-Commit-Position: refs/heads/master@{#37842}
When reading through the source code (v8.h) I found some minor typos
which I wanted to report.
BUG=
Review-Url: https://codereview.chromium.org/2130513002
Cr-Commit-Position: refs/heads/master@{#37835}
Reason for revert:
blink is unhappy about the microtask change
Original issue's description:
> Reland "Don't compile functions in a context the caller doesn't have access to"
>
> Original issue's description:
> > Don't compile functions in a context the caller doesn't have access to
> >
> > Instead just return undefined
> >
> > A side effect of this is that it's no longer possible to compile
> > functions in a detached context.
> >
> > BUG=chromium:541703
> > R=verwaest@chromium.org,bmeurer@chromium.org
>
> BUG=chromium:541703
> R=verwaest@chromium.org
>
> Committed: https://crrev.com/6bceabac5b705b2ce1f52d34650cea1ae3b8c617
> Cr-Commit-Position: refs/heads/master@{#37756}
TBR=verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:541703
Review-Url: https://codereview.chromium.org/2151843002
Cr-Commit-Position: refs/heads/master@{#37760}
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
BUG=chromium:541703
R=verwaest@chromium.org
Review-Url: https://codereview.chromium.org/2143893005
Cr-Commit-Position: refs/heads/master@{#37756}
Currently the code example in the FunctionTemplate class documentation
is out of date. This commit updates the examples so they compile and run
without error.
BUG=
Review-Url: https://codereview.chromium.org/2127523003
Cr-Commit-Position: refs/heads/master@{#37741}
Reason for revert:
Causes crashes on Canary
Original issue's description:
> Don't compile functions in a context the caller doesn't have access to
>
> Instead just return undefined
>
> A side effect of this is that it's no longer possible to compile
> functions in a detached context.
>
> BUG=chromium:541703
> R=verwaest@chromium.org,bmeurer@chromium.org
> CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
>
> Committed: https://crrev.com/992e34c21635b179a993b82ac1d81753e7a6a57a
> Cr-Commit-Position: refs/heads/master@{#37657}
TBR=bmeurer@chromium.org,verwaest@chromium.org,jochen@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:541703, chromium:628053
Review-Url: https://codereview.chromium.org/2148163002
Cr-Commit-Position: refs/heads/master@{#37736}
Instead just return undefined
A side effect of this is that it's no longer possible to compile
functions in a detached context.
BUG=chromium:541703
R=verwaest@chromium.org,bmeurer@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_chromium_rel_ng
Review-Url: https://codereview.chromium.org/2034083002
Cr-Commit-Position: refs/heads/master@{#37657}
Isolate is not going to retain a CPU profiler.
The client will be creating an instance of profiler when needed.
Deprectate v8::Isolate::GetCpuProfiler()
BUG=v8:4789
Review-Url: https://codereview.chromium.org/2117343006
Cr-Commit-Position: refs/heads/master@{#37613}
Such an object can be used to later create a context from it. It has to
have access checks with handlers enabled, as it cannot be accessed
otherwise.
BUG=chromium:618305
R=verwaest@chromium.org
Review-Url: https://codereview.chromium.org/2107673003
Cr-Commit-Position: refs/heads/master@{#37594}
We want to eventually move the profiling functionality out of V8 as library,
this patch exposes TickSample and its APIs in v8-profiler.h so that when
embedders use library, they can have more details.
Minor change: Rename tick-sample.[h|cc] to simulator-helper.[h|cc].
BUG=v8:4789
LOG=N
Review-Url: https://codereview.chromium.org/2105943002
Cr-Commit-Position: refs/heads/master@{#37564}
This patch implements "immutable prototype exotic objects" from the ECMAScript
spec, which are objects whose __proto__ cannot be changed, but are not otherwise
frozen. They are introduced in order to prevent a Proxy from being introduced
to the prototype chain of the global object.
The API is extended by a SetImmutablePrototype() call in ObjectTemplate, which
can be used to vend new immutable prototype objects. Additionally, Object.prototype
is an immutable prototype object.
In the implementation, a new bit is added to Maps to say whether the prototype is
immutable, which is read by SetPrototype. Map transitions to the immutable prototype
state are not saved in the transition tree because the main use case is just for
the prototype chain of the global object, which there will be only one of per
Context, so no need to take up the extra word for a pointer in each full transition
tree.
BUG=v8:5149
Review-Url: https://codereview.chromium.org/2108203002
Cr-Commit-Position: refs/heads/master@{#37482}
This part of the snapshot API should not be in use yet, so we can still
change this. The motivation for this change is:
- Use MaybeHandle where reasonable.
- Remove ambiguity: when we use index to create context from snapshot,
we should not have a silent fallback if snapshot is not available.
- Symmetry: rename to Context::FromSnapshot to mirror templates.
R=jochen@chromium.org
BUG=chromium:617892
Review-Url: https://codereview.chromium.org/2100073002
Cr-Commit-Position: refs/heads/master@{#37334}
We deviate from spec in that, in our implementation, __defineGetter__ on non-
configurable properties returns false instead of throwing a TypeError. This commit
adds a use counter to track how often we would be throwing an error we currently
avoid, to determine if we can change to align with spec or if the spec is not
implementable.
BUG=v8:5070
Review-Url: https://codereview.chromium.org/2089533002
Cr-Commit-Position: refs/heads/master@{#37259}
Base the fast-path in AdjustAmountOfExternalMemory on a value + limit. To
preserve the behavior the limit is just set using kExternalAllocationLimit.
Redo naming of related members.
R=jochen@chromium.org
BUG=chromium:621829
LOG=N
Review-Url: https://codereview.chromium.org/2085893002
Cr-Commit-Position: refs/heads/master@{#37131}
I need this method because of ActiveScriptWrappables, which have to be processed
at the atomic pause even for incremental solution, as there is no other way of
detecting when an object starts or stops being active than querying it.
LOG=no
BUG=468240
Review-Url: https://codereview.chromium.org/2065833003
Cr-Commit-Position: refs/heads/master@{#37062}
With cl https://codereview.chromium.org/2043033002 blink will add new wrappers
to its marking deque (and maintain this deque) so black allocated wrappers are
not a problem anymore. To limit the scope of when blink has to detect wrappers,
we need to tell blink when we start and when we end full gcs. For that we can
nicely use TracePrologue and TraceEpilogue.
LOG=no
BUG=468240
Review-Url: https://codereview.chromium.org/2051103002
Cr-Commit-Position: refs/heads/master@{#36937}
In order to update v8 api and still be able to build chromium, we had to keep
code in suboptimal state. Now when chromium caught up, we can perform cleanup :)
LOG=no
BUG=468240
Review-Url: https://codereview.chromium.org/2057613002
Cr-Commit-Position: refs/heads/master@{#36933}
Reason for revert:
Make MSAN arm bot flaky
Original issue's description:
> Move stack trace extraction code out of TickSample::Init
>
> Make it a part of V8 API GetStackSample function.
> Also expose external_callback_entry in SampleInfo to break dependency
> of clients on internal V8 structures.
>
> BUG=v8:4789
>
> Committed: https://crrev.com/70acfe39c07322144f5fe9b40bb584a8b1099ffd
> Cr-Commit-Position: refs/heads/master@{#36831}
TBR=yangguo@chromium.org,lpy@chromium.org,jochen@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789
Review-Url: https://codereview.chromium.org/2049903002
Cr-Commit-Position: refs/heads/master@{#36835}
Make it a part of V8 API GetStackSample function.
Also expose external_callback_entry in SampleInfo to break dependency
of clients on internal V8 structures.
BUG=v8:4789
Review-Url: https://codereview.chromium.org/2007343003
Cr-Commit-Position: refs/heads/master@{#36831}
This allows using icu data, bundled in the icudtl.dat file,
to be loaded automatically from a default location
side-by-side with the executable.
The v8 stand-alone default is still to use statically
linked ICU data, but this will be switched in a separate
follow-up CL.
BUG=chromium:616033
LOG=y
Review-Url: https://codereview.chromium.org/2042253002
Cr-Commit-Position: refs/heads/master@{#36823}
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
BUG=chromium:611688
LOG=N
TEST=cctest/test-array-buffer-tracker/*
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2036643002
Cr-Commit-Position: refs/heads/master@{#36798}
This cl sketches an api for incremental wrapper tracing, but still uses the api
in the stop-the-world fashion. Responsibility to maintain a marking deque is
transfered to the embedder. V8 will still collect wrapper internal fields, but
will send them to the embedder after each incremental gc task. Wrappers must be
sent at latest by the time next oilpan gc runs - so blink can keep all
discovered wrappables alive.
The old api will be cleared after this cl and corresponding blink cl land.
Comments are very welcomed :)
LOG=no
BUG=468240
Review-Url: https://codereview.chromium.org/2032213003
Cr-Commit-Position: refs/heads/master@{#36761}
Since the generic GetCallingContext is deprecated, but there's still the
use case for the debugger to get the currently debugged context while in
the debug context, add a convenience API for it.
Note that EventDetails already exposes this context, but the embedder
might not necessarily have the EventDetails around.
R=verwaest@chromium.org
BUG=
Review-Url: https://codereview.chromium.org/2040853003
Cr-Commit-Position: refs/heads/master@{#36751}
Reason for revert:
Also failing with the new implementation:
https://build.chromium.org/p/chromium.gpu/builders/Linux%20Debug%20%28NVIDIA%29/builds/62646
Will do a local repro now.
Original issue's description:
> Track based on JSArrayBuffer addresses on pages instead of the attached
> backing store.
>
> Details of tracking:
> - Scavenge: New space pages are processes in bulk on the main thread
> - MC: Unswept pages are processed in bulk in parallel. All other pages
> are processed by the sweeper concurrently.
>
> BUG=chromium:611688
> LOG=N
> TEST=cctest/test-array-buffer-tracker/*
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
>
> Committed: https://crrev.com/279e274eccf95fbb4bd41d908b9153acf6ec118a
> Cr-Commit-Position: refs/heads/master@{#36653}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:611688
Review-Url: https://codereview.chromium.org/2032973002
Cr-Commit-Position: refs/heads/master@{#36663}
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
BUG=chromium:611688
LOG=N
TEST=cctest/test-array-buffer-tracker/*
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2026633003
Cr-Commit-Position: refs/heads/master@{#36653}
Reason for revert:
Breaking
http://build.chromium.org/p/client.v8/builders/V8%20Linux64%20-%20avx2/builds/7972
Original issue's description:
> Track based on JSArrayBuffer addresses on pages instead of the attached
> backing store.
>
> Details of tracking:
> - Scavenge: New space pages are processes in bulk on the main thread
> - MC: Unswept pages are processed in bulk in parallel. All other pages
> are processed by the sweeper concurrently.
>
> BUG=chromium:611688
> LOG=N
> TEST=cctest/test-array-buffer-tracker/*
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
>
> Committed: https://crrev.com/089da007bb990b5b29aab257aa836fdd3f3b8ce0
> Cr-Commit-Position: refs/heads/master@{#36608}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:611688
Review-Url: https://codereview.chromium.org/2028503003
Cr-Commit-Position: refs/heads/master@{#36609}
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
BUG=chromium:611688
LOG=N
TEST=cctest/test-array-buffer-tracker/*
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2024063002
Cr-Commit-Position: refs/heads/master@{#36608}
Expose more or less the full functionality of the KeyAccumulator in the API:
- use the PropertyFilter introduced for GetOwnPropertyNames
- use KeyCollectionLimit for OWN_ONLY or INLCUDE_PROTOS
- use IndexFilter to eithe SKIP_INDICES or INCLUDE_INDICES
Rewire Object::GetOwnPropertyNames to use GetPropertyNames.
BUG=chromium:148757
Review-Url: https://codereview.chromium.org/2002203002
Cr-Commit-Position: refs/heads/master@{#36595}
Users of this api should use a combination of |RequestInterrupt| and
|GCCallback| (see |AddGCPrologueCallback| and friends) to keep track allocated
memory.
BUG=v8:4813
LOG=Y
R=jochen@chromium.org
Review-Url: https://codereview.chromium.org/1991293002
Cr-Commit-Position: refs/heads/master@{#36594}
Reason for revert:
Investigating new arm simulator failure:
https://build.chromium.org/p/client.v8.ports/builders/V8%20Linux%20-%20arm%20-%20sim/builds/851/steps/Check%20-%20novfp3/logs/box2d
Original issue's description:
> Reland "[heap] Fine-grained JSArrayBuffer tracking"
>
> Track based on JSArrayBuffer addresses on pages instead of the attached
> backing store.
>
> Details of tracking:
> - Scavenge: New space pages are processes in bulk on the main thread
> - MC: Unswept pages are processed in bulk in parallel. All other pages
> are processed by the sweeper concurrently.
>
> BUG=chromium:614730, chromium:611688
> LOG=N
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
>
> Committed: https://crrev.com/bc0fb6e83eb7351f52bfd6f780bb6c12bd87c58c
> Cr-Commit-Position: refs/heads/master@{#36592}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:614730, chromium:611688
Review-Url: https://codereview.chromium.org/2021893002
Cr-Commit-Position: refs/heads/master@{#36593}
Track based on JSArrayBuffer addresses on pages instead of the attached
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
BUG=chromium:614730, chromium:611688
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2026463002
Cr-Commit-Position: refs/heads/master@{#36592}
Adds an API to request the total size of code/bytecode and their associated
metadata in the heap. When requested, the code_space, old_space and
large_object_space is scanned to find any code/bytecode array objects.
This could be slow and hence it should be used with caution.
BUG=v8:5019
LOG=N
Review-Url: https://codereview.chromium.org/1997363002
Cr-Commit-Position: refs/heads/master@{#36534}
This patch does five things:
1. Extracts sampler as libsampler to provide sampling functionality support.
2. Makes SampleStack virtual so embedders can override the behaviour of sample collecting.
3. Removes sampler.[h|cc].
4. Moves sampling thread into log.cc as workaround to keep the --prof functionality.
5. Creates SamplerManager to manage the relationship between samplers and threads.
The reason we port hashmap.h is that in debug mode, STL containers are using
mutexes from a mutex pool, which may lead to deadlock when using asynchronously
signal handler.
Currently libsampler is used in V8 temporarily.
BUG=v8:4789
LOG=n
Committed: https://crrev.com/06cc9b7c176a6223971deaa9fbcafe1a05058c7b
Cr-Commit-Position: refs/heads/master@{#36527}
Review-Url: https://codereview.chromium.org/1922303002
Cr-Commit-Position: refs/heads/master@{#36532}
Reason for revert:
Premature revert. Chromium roll included an earlier version.
Original issue's description:
> Revert of "[heap] Fine-grained JSArrayBuffer tracking" (patchset #3 id:80001 of https://codereview.chromium.org/2007253002/ )
>
> Reason for revert:
> Breaks webgl2 conformance tests
> https://bugs.chromium.org/p/chromium/issues/detail?id=614730
>
> Original issue's description:
> > Reland of "[heap] Fine-grained JSArrayBuffer tracking"
> >
> > Track based on JSArrayBuffer addresses on pages instead of the attached
> > backing store.
> >
> > Details of tracking:
> > - Scavenge: New space pages are processes in bulk on the main thread
> > - MC: Unswept pages are processed in bulk in parallel. All other pages
> > are processed by the sweeper concurrently.
> >
> > This reverts commit 93fe04afa9.
> >
> > R=hpayer@chromium.org
> > BUG=chromium:611688
> > LOG=N
> > CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
> >
> > Committed: https://crrev.com/863d015e573798e263b35b31d2ab979739706533
> > Cr-Commit-Position: refs/heads/master@{#36513}
>
> TBR=hpayer@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=chromium:611688
>
> Committed: https://crrev.com/b9b0868ec49a52c9a80c9beea862a61707b292e5
> Cr-Commit-Position: refs/heads/master@{#36524}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:611688
Review-Url: https://codereview.chromium.org/2009383002
Cr-Commit-Position: refs/heads/master@{#36530}
Reason for revert:
V8 Linux64 TSAN failure because ThreadSanitizer indicated data race.
Original issue's description:
> Create libsampler as V8 sampler library.
>
> This patch does five things:
>
> 1. Extracts sampler as libsampler to provide sampling functionality support.
> 2. Makes SampleStack virtual so embedders can override the behaviour of sample collecting.
> 3. Removes sampler.[h|cc].
> 4. Moves sampling thread into log.cc as workaround to keep the --prof functionality.
> 5. Creates SamplerManager to manage the relationship between samplers and threads.
>
> The reason we port hashmap.h is that in debug mode, STL containers are using
> mutexes from a mutex pool, which may lead to deadlock when using asynchronously
> signal handler.
>
> Currently libsampler is used in V8 temporarily.
>
> BUG=v8:4789
> LOG=n
>
> Committed: https://crrev.com/06cc9b7c176a6223971deaa9fbcafe1a05058c7b
> Cr-Commit-Position: refs/heads/master@{#36527}
TBR=jochen@chromium.org,alph@chromium.org,fmeawad@chromium.org,yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=v8:4789
Review-Url: https://codereview.chromium.org/2000323007
Cr-Commit-Position: refs/heads/master@{#36529}
This patch does five things:
1. Extracts sampler as libsampler to provide sampling functionality support.
2. Makes SampleStack virtual so embedders can override the behaviour of sample collecting.
3. Removes sampler.[h|cc].
4. Moves sampling thread into log.cc as workaround to keep the --prof functionality.
5. Creates SamplerManager to manage the relationship between samplers and threads.
The reason we port hashmap.h is that in debug mode, STL containers are using
mutexes from a mutex pool, which may lead to deadlock when using asynchronously
signal handler.
Currently libsampler is used in V8 temporarily.
BUG=v8:4789
LOG=n
Review-Url: https://codereview.chromium.org/1922303002
Cr-Commit-Position: refs/heads/master@{#36527}
Reason for revert:
Breaks webgl2 conformance tests
https://bugs.chromium.org/p/chromium/issues/detail?id=614730
Original issue's description:
> Reland of "[heap] Fine-grained JSArrayBuffer tracking"
>
> Track based on JSArrayBuffer addresses on pages instead of the attached
> backing store.
>
> Details of tracking:
> - Scavenge: New space pages are processes in bulk on the main thread
> - MC: Unswept pages are processed in bulk in parallel. All other pages
> are processed by the sweeper concurrently.
>
> This reverts commit 93fe04afa9.
>
> R=hpayer@chromium.org
> BUG=chromium:611688
> LOG=N
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
>
> Committed: https://crrev.com/863d015e573798e263b35b31d2ab979739706533
> Cr-Commit-Position: refs/heads/master@{#36513}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:611688
Review-Url: https://codereview.chromium.org/2011563003
Cr-Commit-Position: refs/heads/master@{#36524}
Track based on JSArrayBuffer addresses on pages instead of the attached
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
This reverts commit 93fe04afa9.
R=hpayer@chromium.org
BUG=chromium:611688
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2007253002
Cr-Commit-Position: refs/heads/master@{#36513}
Track based on JSArrayBuffer addresses on pages instead of the attached
backing store.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
This reverts commit d2dff0320b.
R=hpayer@chromium.org
BUG=chromium:611688
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/2005723005
Cr-Commit-Position: refs/heads/master@{#36495}
Reason for revert:
Revert it.
Original issue's description:
> [heap] Fine-grained JSArrayBuffer tracking
>
> Track based on JSArrayBuffer addresses instead of the attached backing store.
> This way we can later on iterate buffers on a single page. The reland also
> switches to a page-based implementation where a page contains the set of its
> contained (live and dead) buffers.
>
> Details of tracking:
> - Scavenge: New space pages are processes in bulk on the main thread
> - MC: Unswept pages are processed in bulk in parallel. All other pages
> are processed by the sweeper concurrently.
>
> BUG=chromium:611688
> LOG=N
> CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
>
> Committed: https://crrev.com/b2d8bfc7931eef49d527605ba485950dea41cde3
> Cr-Commit-Position: refs/heads/master@{#36437}
TBR=hpayer@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:611688
Review-Url: https://codereview.chromium.org/2006183003
Cr-Commit-Position: refs/heads/master@{#36461}
Track based on JSArrayBuffer addresses instead of the attached backing store.
This way we can later on iterate buffers on a single page. The reland also
switches to a page-based implementation where a page contains the set of its
contained (live and dead) buffers.
Details of tracking:
- Scavenge: New space pages are processes in bulk on the main thread
- MC: Unswept pages are processed in bulk in parallel. All other pages
are processed by the sweeper concurrently.
BUG=chromium:611688
LOG=N
CQ_EXTRA_TRYBOTS=tryserver.v8:v8_linux_arm64_gc_stress_dbg,v8_linux_gc_stress_dbg,v8_mac_gc_stress_dbg,v8_linux64_tsan_rel,v8_mac64_asan_rel
Review-Url: https://codereview.chromium.org/1964023002
Cr-Commit-Position: refs/heads/master@{#36437}
Handles of this type are automatically reset by the garbage collector
when their objects are not longer reachable.
The motivation is to reduce pause time of external.weak_global_handles
phase of the garbage collector by not maintaing the list of pending
callbacks and not calling the callbacks.
Local testing on discourse page of the v8.inifinite_scroll benchmark
shows 7x improvement for this GC phase.
Before:
external.weak_global_handles
len: 21
min: 0.0
max: 4.5
avg: 0.757142857143
After:
external.weak_global_handles
len: 21
min: 0.0
max: 0.5
avg: 0.109523809524
A follow-up patch will enable the new phantom handles in Chromium.
BUG=chromium:608333
LOG=NO
Review-Url: https://codereview.chromium.org/1950963002
Cr-Commit-Position: refs/heads/master@{#36095}
This removes:
- PersistentBase::SetWeak that takes WeakCallbackData.
The embedders should use the version that takes WeakCallbackInfo.
- PersistentBase::SetPhantom.
The embedders should SetWeak that takes WeakCallbackInfo.
Functions in DefaultPersistentValueMapTraits are changed to accept
WeakCallbackInfo instead of WeakCallbackData.
BUG=chromium:609808
LOG=NO
Review-Url: https://codereview.chromium.org/1953263002
Cr-Commit-Position: refs/heads/master@{#36079}
This method provides ability to get all properties of the object with passed filter in addition to existing GetOwnPropertyNames(context) method that returns only enumerable properties.
BUG=v8:3861,chromium:581495
R=yangguo@chromium.org
LOG=Y
Review-Url: https://codereview.chromium.org/1943773002
Cr-Commit-Position: refs/heads/master@{#36031}
It is already effectively disabled by --scavenge_reclaim_unmodified_objects.
BUG=
Review-Url: https://codereview.chromium.org/1944793002
Cr-Commit-Position: refs/heads/master@{#36018}
This is needed by Blink to implement the Custom Elements spec.
BUG=v8:4261
LOG=y
Review-Url: https://codereview.chromium.org/1910253005
Cr-Commit-Position: refs/heads/master@{#35833}
The Oddball::to_number_raw field contains the actual double value of the
Oddball converted to a number, and is located at the same offset as the
HeapNumber::value field, so for lowering changes we don't need to check
for undefined (or any other oddball explicitly).
R=jarin@chromium.org
Review URL: https://codereview.chromium.org/1922443002
Cr-Commit-Position: refs/heads/master@{#35753}
As the code on the blink side sits down, we realize we don't need isolate arg
anymore. As the heap tracer is set per isolate, it can actually be confusing if
the isolate passed as argument is always the same as the isolate the heap tracer
was set for. Wdyt?
BUG=468240
LOG=no
Review URL: https://codereview.chromium.org/1900953003
Cr-Commit-Position: refs/heads/master@{#35620}
Reason for revert:
node.js is updated now
Original issue's description:
> Revert of [api] Restrict Template::Set to take templates or primitive values (patchset #1 id:1 of https://codereview.chromium.org/1839983002/ )
>
> Reason for revert:
> Breaks node.js
>
> Original issue's description:
> > [api] Restrict Template::Set to take templates or primitive values
> >
> > Embedders that passed in non-primitive values should either use
> > getters/setters (templates) or install a native data property,
> > otherwise, the values would all result in cross-context leaks
> >
> > BUG=none
> > R=verwaest@chromium.org
> > LOG=y
> >
> > Committed: https://crrev.com/eebdee8eafa97849cc70c25f3fecf1b075bac248
> > Cr-Commit-Position: refs/heads/master@{#35244}
>
> TBR=verwaest@chromium.org
> # Skipping CQ checks because original CL landed less than 1 days ago.
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=none
>
> Committed: https://crrev.com/e1674a24ca3cb92bb4e58d368b25767bd61a0dfa
> Cr-Commit-Position: refs/heads/master@{#35264}
TBR=verwaest@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=none
Review URL: https://codereview.chromium.org/1894993002
Cr-Commit-Position: refs/heads/master@{#35572}
PersistentValueMap is used to hold per-world wrappers in the blink. Currently,
when we trace wrappers, we visit wrappers in all worlds via this PersistentValueMap. This cl introduces convenient (and faster) way of registering these external references.
BUG=468240
LOG=no
Review URL: https://codereview.chromium.org/1883043003
Cr-Commit-Position: refs/heads/master@{#35523}
To keep track of memory characteristics of a JS program use
GetHeapSpaceStatistics from a combination of
- a GC epilogue callback registered using AddGCEpilogueCallback
- an interrupt registered using RequestInterrupt
Rationale:
The feature is currently broken as those callbacks are (also) executed from
background threads, breaking our implicit contract for only performing callbacks
on the foreground thread. Furhtermore, it's not clear for the embedder whether
these allocations originate in JS, or are required for a GC.
Note:
- The already deprecated non-isolate versions are removed with this CL.
R=jochen@chromium.org
BUG=v8:4813
LOG=Y
Review URL: https://codereview.chromium.org/1886573006
Cr-Commit-Position: refs/heads/master@{#35474}
When the embedder sets the heap tracer, V8, during marking, will collect all reachable wrappers, and then ask embedder to trace its heap. The embedder is expected to call PersistentBase::RegisterExternalReference with all wrappers reachable from the given ones. This fixed point iteration happens in MarkCompact::ProcessEphemeralMarking.
For more efficient object visiting during marking, we need a special JS_API_OBJECT_TYPE (in tandem with already existing JS_SPECIAL_API_OBJECT_TYPE) and corresponding visitor (JSApiObjectVisitor).
BUG=chromium:468240
LOG=no
Review URL: https://codereview.chromium.org/1844413002
Cr-Commit-Position: refs/heads/master@{#35412}
This is a convenience API that an embedder can use to do final checks on
the return value. Note that this creates a new handle and thus defeats
the performance optimization done for ReturnValue - an embedder should
only use this in non-performance critical code paths.
BUG=
R=verwaest@chromium.org
Review URL: https://codereview.chromium.org/1875263003
Cr-Commit-Position: refs/heads/master@{#35409}
The previous code cache system required stubs to be marked with a StubType, causing them to be inserted either into a fixed array or into a dictionary-mode code cache. This could cause names to be in both cases, and lookup would just find the "fast" one first. Given that we clear out the caches on each GC, the memory overhead shouldn't be too bad. Additionally, the dictionary itself should just stay linear for small arrays; that's faster anyway.
This CL additionally deletes some dead IC code.
BUG=
Review URL: https://codereview.chromium.org/1846963002
Cr-Commit-Position: refs/heads/master@{#35291}
Reason for revert:
Breaks node.js
Original issue's description:
> [api] Restrict Template::Set to take templates or primitive values
>
> Embedders that passed in non-primitive values should either use
> getters/setters (templates) or install a native data property,
> otherwise, the values would all result in cross-context leaks
>
> BUG=none
> R=verwaest@chromium.org
> LOG=y
>
> Committed: https://crrev.com/eebdee8eafa97849cc70c25f3fecf1b075bac248
> Cr-Commit-Position: refs/heads/master@{#35244}
TBR=verwaest@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none
Review URL: https://codereview.chromium.org/1860003002
Cr-Commit-Position: refs/heads/master@{#35264}
Embedders that passed in non-primitive values should either use
getters/setters (templates) or install a native data property,
otherwise, the values would all result in cross-context leaks
BUG=none
R=verwaest@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1839983002
Cr-Commit-Position: refs/heads/master@{#35244}
We expect that the majority of malloc'd memory held by V8 is allocated
in Zone objects. Introduce an Allocator class that is used by Zones to
manage memory, and allows for querying the current usage.
BUG=none
R=titzer@chromium.org,bmeurer@chromium.org,jarin@chromium.org
LOG=n
TBR=rossberg@chromium.org
Review URL: https://codereview.chromium.org/1847543002
Cr-Commit-Position: refs/heads/master@{#35196}
Change x64 to use the external references like all other platforms.
BUG=chromium:581076
LOG=N
Review URL: https://codereview.chromium.org/1844283002
Cr-Commit-Position: refs/heads/master@{#35160}
Reason for revert:
Violates ES6 spec (crbug.com/4850), and implementation was over-eager. Will revert for now.
Original issue's description:
> Parser: Make skipping HTML comments optional.
>
> API change: This adds a new flag skip_html_comments to v8::ScriptOriginOptions. This flag controls whether V8 will attempt to honour HTML-style comments in JS sources.
>
> (That is: Gracefully ignore <!-- ... ---> in JS sources, which was a popular technique in the early days of JavaScript, to prevent non-JS-enabled browsers from displaying script sources to uses.)
>
> The flag defaults to 'true' when using v8::ScriptOrigin constructor, which preserves the existing behaviour. Embedders which are happy with the existing behaviour will thus not need any changes.
>
> BUG=chromium:573887
> LOG=Y
>
> Committed: https://crrev.com/91d344288aa51ed03eaaa1cb3e368ac1e82f0173
> Cr-Commit-Position: refs/heads/master@{#34904}
TBR=jochen@chromium.org,rossberg@chromium.org
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=chromium:573887, v8:4850
LOG=Y
Review URL: https://codereview.chromium.org/1817163003
Cr-Commit-Position: refs/heads/master@{#34958}
I first need to figure out what to do about window.document before we
can deprecate this: window.document is a regular accessor, however, once
the window navigated from about:blank, its value will never change.
Blink uses ForceSet to then replace the accessor with a data constant
which has way better performance than invoking the accessor all the
time.
Since the accessor, however, is installed as read only &
non-configurable, there is no spec compliant way to pull this off right
now
BUG=chromium:595601
R=verwaest@chromium.org
LOG=y
Review URL: https://codereview.chromium.org/1816033002
Cr-Commit-Position: refs/heads/master@{#34919}
API change: This adds a new flag skip_html_comments to v8::ScriptOriginOptions. This flag controls whether V8 will attempt to honour HTML-style comments in JS sources.
(That is: Gracefully ignore <!-- ... ---> in JS sources, which was a popular technique in the early days of JavaScript, to prevent non-JS-enabled browsers from displaying script sources to uses.)
The flag defaults to 'true' when using v8::ScriptOrigin constructor, which preserves the existing behaviour. Embedders which are happy with the existing behaviour will thus not need any changes.
BUG=chromium:573887
LOG=Y
Review URL: https://codereview.chromium.org/1801203002
Cr-Commit-Position: refs/heads/master@{#34904}
A startup snapshot is considered cold when it does not contain any
function code. We can now create a warm startup snapshot from a cold one
by running a warm-up script. Functions exercised by the warm-up script
are compiled and its code included in the warm startup snapshot. Side
effects caused by the warm-up script does not persist.
R=vogelheim@chromium.org
BUG=v8:4836
LOG=Y
Review URL: https://codereview.chromium.org/1805903002
Cr-Commit-Position: refs/heads/master@{#34849}
We have compatibility workarounds to return 'undefined' on accessors
to RegExp.prototype. This patch adds two UseCounters for two categories
of this non-spec-compliant path:
- source
- ignorecase, multiline, global
R=yangguo
BUG=chromium:581577
LOG=Y
Review URL: https://codereview.chromium.org/1762423002
Cr-Commit-Position: refs/heads/master@{#34597}
This scope is used to control microtasks execution when MicrotasksPolicy::kScoped is engaged.
Attempt #2. First one was reverted due to chromium breakage: SetAutorunMicrotasks(false) was broken.
BUG=chromium:585949
LOG=Y
TEST=ScopedMicrotasks
Review URL: https://codereview.chromium.org/1741893003
Cr-Commit-Position: refs/heads/master@{#34504}
Blink wants to distinguish GCs triggered by CollectAllAvailableGarbage
from GCs forced by testing. This CL introduces a new flag to differentiate
the two GC types.
BUG=591463
LOG=Y
Review URL: https://codereview.chromium.org/1757263003
Cr-Commit-Position: refs/heads/master@{#34494}
Reason for revert:
[Sheriff] Speculative. Seems to break a bunch of webkit tests and causes timeouts:
https://build.chromium.org/p/client.v8.fyi/builders/V8-Blink%20Linux%2064/builds/5103
Please rebase upstream if intended.
Original issue's description:
> Introduce v8::MicrotasksScope.
>
> This scope is used to control microtasks execution when MicrotasksPolicy::kScoped is engaged.
>
> BUG=chromium:585949
> LOG=Y
> TEST=ScopedMicrotasks
>
> Committed: https://crrev.com/db77cec242dbdf8ee26da8232fa930270429f253
> Cr-Commit-Position: refs/heads/master@{#34472}
TBR=jochen@chromium.org,adamk@chromium.org,dgozman@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:585949
Review URL: https://codereview.chromium.org/1762943002
Cr-Commit-Position: refs/heads/master@{#34480}
This scope is used to control microtasks execution when MicrotasksPolicy::kScoped is engaged.
BUG=chromium:585949
LOG=Y
TEST=ScopedMicrotasks
Review URL: https://codereview.chromium.org/1741893003
Cr-Commit-Position: refs/heads/master@{#34472}
ES2015 generally bans FunctionDeclarations in positions which expect a Statement,
as opposed to a StatementListItem, such as a FunctionDeclaration which constitutes
the body of a for loop. However, Annex B 3.2 and 3.4 make exceptions for labeled
function declarations and function declarations as the body of an if statement in
sloppy mode, in the latter case specifying that the semantics are as if the
function declaration occurred in a block. Chrome has historically permitted
further extensions, for the body of any flow control construct.
This patch addresses both the syntactic and semantic mismatches between V8 and
the spec. For the semantic mismatch, function declarations as the body of if
statements change from unconditionally hoisting in certain cases to acquiring
the sloppy mode function in block semantics (based on Annex B 3.3). For the
extra syntax permitted, this patch adds a flag,
--harmony-restrictive-declarations, which excludes disallowed function declaration
cases. A new UseCounter, LegacyFunctionDeclaration, is added to count how often
function declarations occur as the body of other constructs in sloppy mode. With
this patch, the code generally follows the form of the specification with respect
to parsing FunctionDeclarations, rather than allowing them in arbitrary Statement
positions, and makes it more clear where our extensions occur.
BUG=v8:4647
R=adamk
LOG=Y
Review URL: https://codereview.chromium.org/1757543003
Cr-Commit-Position: refs/heads/master@{#34470}
This introduces a new instance type and reorders the JSObject types so any type requiring special LookupIterator support can be identified with a single range check.
In addition, it restructures the Next for better performance, avoiding unnecessary calls.
BUG=
Review URL: https://codereview.chromium.org/1751043002
Cr-Commit-Position: refs/heads/master@{#34429}
Rename the existing (patching) ToBooleanStub to ToBooleanICStub to match
our naming convention, and add a new TurboFan-powered ToBooleanStub,
which just does the ToBoolean conversion without any runtime call or
code patching, so we can use it for Ignition (and TurboFan).
Drive-by-fix: Add an Oddball::to_boolean field similar to the ones we
already have for to_string and to_number, so we don't need to actually
dispatch on the concrete Oddball at all.
R=epertoso@chromium.org, rmcilroy@chromium.org, yangguo@chromium.org
Review URL: https://codereview.chromium.org/1744163002
Cr-Commit-Position: refs/heads/master@{#34361}
This patch adds the newly added support for contexts in V8 Tracing, as well
as use it to mark all the entry points for a V8 Isolate.
Update for reland: The current tracing interface needs to be updated (AddTraceEvent),
but the embedders need to migrate to the new version before removing the old version.
(Reland of: https://codereview.chromium.org/1686233002)
The revert happened because the 2 signatures of the old and new AddTraceEvent where different
so it threw an overload-virtual error on cross arm debug. This issue is temporary, and to solve
it, I added an implementation of the old and new everywhere until the embedder implements the new.
BUG=v8:4565
LOG=N
R=jochen@chromium.org
Review URL: https://codereview.chromium.org/1704253002
Cr-Commit-Position: refs/heads/master@{#34332}
This calback is run after an attempt to run microtasks.
BUG=chromium:585949
LOG=Y
Review URL: https://codereview.chromium.org/1731773005
Cr-Commit-Position: refs/heads/master@{#34305}
This patch makes ArraySpeciesCreate fast in V8 by avoiding two property reads
when the following conditions are met:
- No Array instance has had its __proto__ reset
- No Array instance has had a constructor property defined
- Array.prototype has not had its constructor changed
- Array[Symbol.species] has not been reset
For subclasses of Array, or for conditions where one of these assumptions is
violated, the full lookup of species is done according to the ArraySpeciesCreate
algorithm. Although this is a "performance cliff", it does not come up in the
expected typical use case of @@species (Array subclassing), so it is hoped that
this can form a good start. Array subclasses will incur the slowness of looking
up @@species, but their use won't slow down invocations of, for example,
Array.prototype.slice on Array base class instances.
Possible future optimizations:
- For the fallback case where the assumptions don't hold, optimize the two
property lookups.
- For Array.prototype.slice and Array.prototype.splice, even if the full lookup
of @@species needs to take place, we still could take the rest of the C++
fastpath. However, to do this correctly requires changing the calling convention
from C++ to JS to pass the @@species out, so it is not attempted in this patch.
With this patch, microbenchmarks of Array.prototype.slice do not suffer a
noticeable performance regression, unlike their previous 2.5x penalty.
TBR=hpayer@chromium.org
Review URL: https://codereview.chromium.org/1689733002
Cr-Commit-Position: refs/heads/master@{#34199}
This new callback is similar to CallCompletedCallback, but is executed before the call has been made.
Added Isolate* parameter to CallCompletedCallback, marking previous one as deprecated.
BUG=chromium:585949
LOG=Y
Review URL: https://codereview.chromium.org/1689863002
Cr-Commit-Position: refs/heads/master@{#34167}
This patch adds the newly added support for contexts in V8 Tracing, as well
as use it to mark all the entry points for a V8 Isolate.
BUG=v8:4565
LOG=N
Review URL: https://codereview.chromium.org/1686233002
Cr-Commit-Position: refs/heads/master@{#34092}
The call can be used by the embedder to provide information on the workers
executing background tasks.
BUG=chromium:524425
LOG=N
Review URL: https://codereview.chromium.org/1664203004
Cr-Commit-Position: refs/heads/master@{#33788}
(Trying to finish FastAccessorAssembler this week. This should make it easier to pick up the Blink side of this work later on.)
BUG=chromium:508898
SOUNDTRACK=http://youtu.be/i1EG-MKy4so
LOG=Y
Review URL: https://codereview.chromium.org/1620293002
Cr-Commit-Position: refs/heads/master@{#33671}
This patch adds a UseCounter for each of the following:
- Allowing duplicate sloppy-mode block-scoped function declarations
in the exact same scope
- for-in loops with an initializer
The patch also refactors some of the declaration code to clean it up and
enable the first counter, and adds additional unit tests to nail down
the semantics of edge cases of sloppy-mode block-scoped function declarations.
BUG=v8:4693,chromium:579395
LOG=N
R=adamk
Review URL: https://codereview.chromium.org/1633743003
Cr-Commit-Position: refs/heads/master@{#33650}
Without this change, the v8::Local<> constructor will be picked up by the
compiler as an option for an implicit cast for any pointer type. This leads
to bad error messages when accidentally passing an erroneous pointer type to
a function wanting a Local<> (complains about a pointer assignment in Local<>'s
constructor as opposed to a bad type for the parameter of the function being
called) and also causes ambiguity errors where none should exist when calling
overloaded functions (for example a function taking either a std::string or a
v8::Local<v8::Script> cannot be called with a const char * because the compiler
sees both types as being constructable with a const char *).
R=jochen@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1647833005
Cr-Commit-Position: refs/heads/master@{#33602}
It allows embedder to inject a stack sample on demand.
BUG=chromium:579191
LOG=N
Review URL: https://codereview.chromium.org/1631043002
Cr-Commit-Position: refs/heads/master@{#33527}
