* Hash code is now just done with a private own symbol instead of the hidden string, which predates symbols.
* In the long run we should do all hidden properties this way and get rid of the
hidden magic 0-length string with the zero hash code. The advantages include
less complexity and being able to do things from JS in a natural way.
* Initially, the performance of weak set regressed, because it's a little harder
to do the lookup in C++. Instead of heroics in C++ to make things faster I
moved some functionality into JS and got the performance back. JS is supposed to be good at looking up named properties on objects.
* This also changes hash codes of Smis so that they are always Smis.
Performance figures are in the comments to the code review. Summary: Most of js-perf-test/Collections is neutral. Set and Map with object keys are 40-50% better. WeakMap is -5% and WeakSet is +9%. After the measurements, I fixed global proxies, which cost 1% on most tests and 5% on the weak ones :-(.
In the code review comments is a patch with an example of the heroics we could do in C++ to make lookup faster (I hope we don't have to do this. Instead of checking for the property, then doing a new lookup to insert it, we could do one lookup and handle the addition immediately). With the current benchmarks above this buys us nothing, but if we go back to doing more lookups in C++ instead of in stubs and JS then it's a win.
In a similar vein we could give the magic zero hash code to the hash code
symbol. Then when we look up the hash code we would sometimes see the table
with all the hidden properties. This dual use of the field for either the hash
code or the table with all hidden properties and the hash code is rather ugly,
and this CL gets rid of it. I'd be loath to bring it back. On the benchmarks quoted above it's slightly slower than moving the hash code lookup to JS like in this CL.
One worry is that the benchmark results above are more monomorphic than real
world code, so may be overstating the performance benefits of moving to JS. I
think this is part of a general issue we have with handling polymorphic code in
JS and any solutions there will benefit this solution, which boils down to
regular property access. Any improvement there will lift all boats.
R=adamk@chromium.org, verwaest@chromium.org
BUG=
Review URL: https://codereview.chromium.org/1149863005
Cr-Commit-Position: refs/heads/master@{#28622}
This adds a new external type (v8::SharedArrayBuffer) that uses a JSArrayBuffer
under the hood. It can be distinguished from an ArrayBuffer by the newly-added
is_shared() bit.
Currently there is no difference in functionality between a SharedArrayBuffer
and an ArrayBuffer. However, a future CL will add the Atomics API, which is
only available on an SharedArrayBuffer. All non-atomic accesses are identical
to ArrayBuffer accesses.
LOG=N
BUG=
Review URL: https://codereview.chromium.org/1136553006
Cr-Commit-Position: refs/heads/master@{#28594}
Reason for revert:
breaks build
Original issue's description:
> Implement SharedArrayBuffer.
>
> This adds a new external type (v8::SharedArrayBuffer) that uses a JSArrayBuffer under the hood. It can be distinguished from an ArrayBuffer by the newly-added is_shared() bit.
>
> Currently there is no difference in functionality between a SharedArrayBuffer and an ArrayBuffer. However, a future CL will add the Atomics API, which is only available on an SharedArrayBuffer. All non-atomic accesses are identical to ArrayBuffer accesses.
>
> BUG=
>
> Committed: https://crrev.com/57170bff7baf341c666252a7f6a49e9c08d51263
> Cr-Commit-Position: refs/heads/master@{#28588}
TBR=jarin@chromium.org,jochen@chromium.org,binji@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=
Review URL: https://codereview.chromium.org/1149203003
Cr-Commit-Position: refs/heads/master@{#28589}
This adds a new external type (v8::SharedArrayBuffer) that uses a JSArrayBuffer under the hood. It can be distinguished from an ArrayBuffer by the newly-added is_shared() bit.
Currently there is no difference in functionality between a SharedArrayBuffer and an ArrayBuffer. However, a future CL will add the Atomics API, which is only available on an SharedArrayBuffer. All non-atomic accesses are identical to ArrayBuffer accesses.
BUG=
Review URL: https://codereview.chromium.org/1136553006
Cr-Commit-Position: refs/heads/master@{#28588}
This just delegates to SharedFunctionInfo::optimization_disabled and
was primarily used for assertions. Removing it due to misleading name
because already optimized functions reported being "non-optimizable".
This relands commit 181d7b8597.
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1146423002
Cr-Commit-Position: refs/heads/master@{#28577}
Reason for revert:
Causes assertions to fire when serializing optimized code.
Original issue's description:
> Remove obsolete JSFunction::IsOptimizable predicate.
>
> This just delegates to SharedFunctionInfo::optimization_disabled and
> was primarily used for assertions. Removing it due to misleading name
> because already optimized functions reported being "non-optimizable".
>
> R=titzer@chromium.org
>
> Committed: https://crrev.com/181d7b85977eb752b19e1de902093783e31330ef
> Cr-Commit-Position: refs/heads/master@{#28551}
TBR=titzer@chromium.org,bmeurer@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Review URL: https://codereview.chromium.org/1148973005
Cr-Commit-Position: refs/heads/master@{#28554}
This just delegates to SharedFunctionInfo::optimization_disabled and
was primarily used for assertions. Removing it due to misleading name
because already optimized functions reported being "non-optimizable".
R=titzer@chromium.org
Review URL: https://codereview.chromium.org/1150683002
Cr-Commit-Position: refs/heads/master@{#28551}
This allows enabling TurboFan on a certain subset of language features
in the AstNumberingVisitor. The heuristics of when to optimize remain
unchanged, only the choice of which optimizing compiler to use changes.
R=bmeurer@chromium.org
BUG=v8:4131
LOG=N
Review URL: https://codereview.chromium.org/1155503002
Cr-Commit-Position: refs/heads/master@{#28544}
This flag mostly duplicates SharedFunctionInfo::optimization_disabled
and is only queried in places where the original is available. Remove
the brittle and error-prone duplication.
R=bmeurer@chromium.org
Review URL: https://codereview.chromium.org/1148043002
Cr-Commit-Position: refs/heads/master@{#28520}
When the page is controlled by a ServiceWorker, the ServiceWorker can return an opaque (non-CORS cross origin) resource response.
We need to treat the messages from such script resource as opaque.
Committed: https://crrev.com/7a599c5e1242d3c5ab7515ee149623da90ae69ec
Cr-Commit-Position: refs/heads/master@{#28445}
Review URL: https://codereview.chromium.org/1140673002
Cr-Commit-Position: refs/heads/master@{#28459}
When the page is controlled by a ServiceWorker, the ServiceWorker can return an opaque (non-CORS cross origin) resource response.
We need to treat the messages from such script resource as opaque.
Review URL: https://codereview.chromium.org/1140673002
Cr-Commit-Position: refs/heads/master@{#28445}
Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
BUG=chromium:481845
LOG=Y
Review URL: https://codereview.chromium.org/1134193002
Cr-Commit-Position: refs/heads/master@{#28371}
Reason for revert:
GC mole issues: https://chromegw.corp.google.com/i/client.v8/builders/V8%20Linux%20-%20gcmole/builds/1950/steps/GCMole%20ia32/logs/stdio
Original issue's description:
> Provide accessor for object internal properties that doesn't require debugger to be active
>
> Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
>
> Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
>
> BUG=chromium:481845
> LOG=Y
>
> Committed: https://crrev.com/bdeb0de88c8cf5f2c78f261b45314138f525110d
> Cr-Commit-Position: refs/heads/master@{#28362}
TBR=pfeldman@chromium.org,kozyatinskiy@chromium.org,yurys@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=chromium:481845
Review URL: https://codereview.chromium.org/1133243002
Cr-Commit-Position: refs/heads/master@{#28365}
Some of the DevTools' clients need to inspect JS objects without enabling debugger. This CL allows to inspect object's internal properties without enabling debugger and instantiating debug context.
Note that now debug context can be created lazily if v8::Debug::GetDebugContext is called when there is no debug listener. This is fragile and has already resulted in some subtle error. I'm going to fix that in a separate CL.
BUG=chromium:481845
LOG=Y
Review URL: https://codereview.chromium.org/1126103006
Cr-Commit-Position: refs/heads/master@{#28362}
In follow-up CLs the scavenger and the MC collector should also respect the unalignment of heap numbers.
BUG=
Review URL: https://codereview.chromium.org/1141523002
Cr-Commit-Position: refs/heads/master@{#28360}
Allows for getting rid of the special casing for float64 and is probably
faster.
BUG=v8:3996
R=verwaest@chromium.org,dslomov@chromium.org,plind44@gmail.com
LOG=n
Review URL: https://codereview.chromium.org/1128433006
Cr-Commit-Position: refs/heads/master@{#28281}
An initial 'code age' state that will turn into a 'pre-aging' code age only after it was executed the first time.
BUG=470930
LOG=Y
Review URL: https://codereview.chromium.org/1107233004
Cr-Commit-Position: refs/heads/master@{#28162}
Original issue's description:
> Remove the weak list of array buffers
>
> Instead, collect live array buffers during marking and free pointers we
> no longer found.
>
> BUG=v8:3996
> R=hpayer@chromium.org
> LOG=n
BUG=v8:3996
TBR=hpayer@chromium.org
LOG=n
Review URL: https://codereview.chromium.org/1115853004
Cr-Commit-Position: refs/heads/master@{#28156}