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// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "gin/gin_features.h"
#include "base/metrics/field_trial_params.h"
namespace features {
// Enable code space compaction when finalizing a full GC with stack.
BASE_FEATURE(kV8CompactCodeSpaceWithStack,
"V8CompactCodeSpaceWithStack",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enable compaction when finalizing a full GC with stack.
BASE_FEATURE(kV8CompactWithStack,
"V8CompactWithStack",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables compaction of maps in a full GC.
BASE_FEATURE(kV8CompactMaps,
"V8CompactMaps",
base::FEATURE_DISABLED_BY_DEFAULT);
// Crashes on evacuation failures in a full GC instead of aborting evacuation.
BASE_FEATURE(kV8CrashOnEvacuationFailure,
"V8CrashOnEvacuationFailure",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables a separate heap space for all map objects.
BASE_FEATURE(kV8UseMapSpace, "V8UseMapSpace", base::FEATURE_ENABLED_BY_DEFAULT);
// Enables optimization of JavaScript in V8.
BASE_FEATURE(kV8OptimizeJavascript,
"V8OptimizeJavascript",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables flushing of JS bytecode in V8.
BASE_FEATURE(kV8FlushBytecode,
"V8FlushBytecode",
base::FEATURE_ENABLED_BY_DEFAULT);
const base::FeatureParam<int> kV8FlushBytecodeOldAge{
&kV8FlushBytecode, "V8FlushBytecodeOldAge", 5};
// Enables flushing of baseline code in V8.
BASE_FEATURE(kV8FlushBaselineCode,
"V8FlushBaselineCode",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables finalizing streaming JS compilations on a background thread.
BASE_FEATURE(kV8OffThreadFinalization,
"V8OffThreadFinalization",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables lazy feedback allocation in V8.
BASE_FEATURE(kV8LazyFeedbackAllocation,
"V8LazyFeedbackAllocation",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables per-context marking worklists in V8 GC.
BASE_FEATURE(kV8PerContextMarkingWorklist,
"V8PerContextMarkingWorklist",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables flushing of the instruction cache for the embedded blob.
BASE_FEATURE(kV8FlushEmbeddedBlobICache,
"V8FlushEmbeddedBlobICache",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables reduced number of concurrent marking tasks.
BASE_FEATURE(kV8ReduceConcurrentMarkingTasks,
"V8ReduceConcurrentMarkingTasks",
base::FEATURE_DISABLED_BY_DEFAULT);
// Disables reclaiming of unmodified wrappers objects.
BASE_FEATURE(kV8NoReclaimUnmodifiedWrappers,
"V8NoReclaimUnmodifiedWrappers",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables W^X code memory protection in V8.
// This is enabled in V8 by default. To test the performance impact, we are
// going to disable this feature in a finch experiment.
BASE_FEATURE(kV8CodeMemoryWriteProtection,
"V8CodeMemoryWriteProtection",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables fallback to a breadth-first regexp engine on excessive backtracking.
BASE_FEATURE(kV8ExperimentalRegexpEngine,
"V8ExperimentalRegexpEngine",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables experimental Maglev compiler.
BASE_FEATURE(kV8Maglev, "V8Maglev", base::FEATURE_DISABLED_BY_DEFAULT);
// Enables Sparkplug compiler. Note that this only sets the V8 flag when
// manually overridden; otherwise it defers to whatever the V8 default is.
BASE_FEATURE(kV8Sparkplug, "V8Sparkplug", base::FEATURE_ENABLED_BY_DEFAULT);
// Enables the concurrent Sparkplug compiler.
BASE_FEATURE(kV8ConcurrentSparkplug,
"V8ConcurrentSparkplug",
base::FEATURE_DISABLED_BY_DEFAULT);
const base::FeatureParam<int> kV8ConcurrentSparkplugMaxThreads{
&kV8ConcurrentSparkplug, "V8ConcurrentSparkplugMaxThreads", 0};
BASE_FEATURE(kV8ConcurrentSparkplugHighPriorityThreads,
"V8ConcurrentSparkplugHighPriorityThreads",
base::FEATURE_DISABLED_BY_DEFAULT);
// Makes sure the experimental Sparkplug compiler is only enabled if short
// builtin calls are enabled too.
BASE_FEATURE(kV8SparkplugNeedsShortBuiltinCalls,
"V8SparkplugNeedsShortBuiltinCalls",
base::FEATURE_DISABLED_BY_DEFAULT);
// Enables short builtin calls feature.
BASE_FEATURE(kV8ShortBuiltinCalls,
"V8ShortBuiltinCalls",
base::FEATURE_ENABLED_BY_DEFAULT);
// Enables fast API calls in TurboFan.
BASE_FEATURE(kV8TurboFastApiCalls,
"V8TurboFastApiCalls",
base::FEATURE_ENABLED_BY_DEFAULT);
// Artificially delays script execution.
BASE_FEATURE(kV8ScriptAblation,
"V8ScriptAblation",
base::FEATURE_DISABLED_BY_DEFAULT);
const base::FeatureParam<int> kV8ScriptDelayOnceMs{&kV8ScriptAblation,
"V8ScriptDelayOnceMs", 0};
const base::FeatureParam<int> kV8ScriptDelayMs{&kV8ScriptAblation,
"V8ScriptDelayMs", 0};
const base::FeatureParam<double> kV8ScriptDelayFraction{
&kV8ScriptAblation, "V8ScriptDelayFraction", 0.0};
// Enables slow histograms that provide detailed information at increased
// runtime overheads.
BASE_FEATURE(kV8SlowHistograms,
"V8SlowHistograms",
base::FEATURE_DISABLED_BY_DEFAULT);
// Multiple finch experiments might use slow-histograms. We introduce
// separate feature flags to circumvent finch limitations.
BASE_FEATURE(kV8SlowHistogramsCodeMemoryWriteProtection,
"V8SlowHistogramsCodeMemoryWriteProtection",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kV8SlowHistogramsSparkplug,
"V8SlowHistogramsSparkplug",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kV8SlowHistogramsSparkplugAndroid,
"V8SlowHistogramsSparkplugAndroid",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kV8SlowHistogramsScriptAblation,
"V8SlowHistogramsScriptAblation",
base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE(kV8DelayMemoryReducer,
"V8DelayMemoryReducer",
base::FEATURE_DISABLED_BY_DEFAULT);
const base::FeatureParam<base::TimeDelta> kV8MemoryReducerStartDelay{
&kV8DelayMemoryReducer, "delay", base::Seconds(8)};
} // namespace features
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