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deps: V8: backport 22014de00115
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Original commit message:

    Reland "[snapshot] rehash JSMap and JSSet during deserialization"

    This is a reland of 8374feed55a5b3010f2e9593560a2d84f9f6725f.

    Fixed rehashing of global proxy keys by creating its identity hash
    early, before the deserialization of the context snapshot.

    Original change's description:
    > [snapshot] rehash JSMap and JSSet during deserialization
    >
    > To rehash JSMap and JSSet, we simply replace the backing store
    > with a new one created with the new hash.
    >
    > Bug: v8:9187
    > Change-Id: I90c25b18b33b7bc2b6ffe1b89fe17aa5f978b517
    > Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2143983
    > Commit-Queue: Joyee Cheung <joyee@igalia.com>
    > Reviewed-by: Jakob Gruber <jgruber@chromium.org>
    > Reviewed-by: Camillo Bruni <cbruni@chromium.org>
    > Cr-Commit-Position: refs/heads/master@{#67663}

    Bug: v8:9187, v8:10523
    Change-Id: I7a0319b1d10ff07644de902fec43e7c2b1dd8da9
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2212085
    Reviewed-by: Leszek Swirski <leszeks@chromium.org>
    Reviewed-by: Camillo Bruni <cbruni@chromium.org>
    Reviewed-by: Jakob Gruber <jgruber@chromium.org>
    Commit-Queue: Joyee Cheung <joyee@igalia.com>
    Cr-Commit-Position: refs/heads/master@{#67999}

Refs: v8/v8@22014de

Backport-PR-URL: #34356
PR-URL: #33300
Refs: v8/v8@ea0719b
Refs: v8/v8@bb9f0c2
Refs: #17058
Reviewed-By: Jiawen Geng <technicalcute@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
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joyeecheung authored and MylesBorins committed Jul 16, 2020
1 parent 01e7886 commit fb180ac
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Showing 12 changed files with 104 additions and 16 deletions.
2 changes: 1 addition & 1 deletion common.gypi
Expand Up @@ -36,7 +36,7 @@

# Reset this number to 0 on major V8 upgrades.
# Increment by one for each non-official patch applied to deps/v8.
'v8_embedder_string': '-node.9',
'v8_embedder_string': '-node.10',

##### V8 defaults for Node.js #####

Expand Down
6 changes: 5 additions & 1 deletion deps/v8/src/heap/factory.cc
Expand Up @@ -2772,8 +2772,12 @@ Handle<JSGlobalProxy> Factory::NewUninitializedJSGlobalProxy(int size) {
map->set_is_access_check_needed(true);
map->set_may_have_interesting_symbols(true);
LOG(isolate(), MapDetails(*map));
return Handle<JSGlobalProxy>::cast(
Handle<JSGlobalProxy> proxy = Handle<JSGlobalProxy>::cast(
NewJSObjectFromMap(map, AllocationType::kYoung));
// Create identity hash early in case there is any JS collection containing
// a global proxy key and needs to be rehashed after deserialization.
proxy->GetOrCreateIdentityHash(isolate());
return proxy;
}

void Factory::ReinitializeJSGlobalProxy(Handle<JSGlobalProxy> object,
Expand Down
2 changes: 1 addition & 1 deletion deps/v8/src/objects/heap-object.h
Expand Up @@ -191,7 +191,7 @@ class HeapObject : public Object {
bool CanBeRehashed() const;

// Rehash the object based on the layout inferred from its map.
void RehashBasedOnMap(ReadOnlyRoots root);
void RehashBasedOnMap(Isolate* isolate);

// Layout description.
#define HEAP_OBJECT_FIELDS(V) \
Expand Down
2 changes: 2 additions & 0 deletions deps/v8/src/objects/js-collection.h
Expand Up @@ -30,6 +30,7 @@ class JSSet : public TorqueGeneratedJSSet<JSSet, JSCollection> {
public:
static void Initialize(Handle<JSSet> set, Isolate* isolate);
static void Clear(Isolate* isolate, Handle<JSSet> set);
void Rehash(Isolate* isolate);

// Dispatched behavior.
DECL_PRINTER(JSSet)
Expand All @@ -56,6 +57,7 @@ class JSMap : public TorqueGeneratedJSMap<JSMap, JSCollection> {
public:
static void Initialize(Handle<JSMap> map, Isolate* isolate);
static void Clear(Isolate* isolate, Handle<JSMap> map);
void Rehash(Isolate* isolate);

// Dispatched behavior.
DECL_PRINTER(JSMap)
Expand Down
38 changes: 34 additions & 4 deletions deps/v8/src/objects/objects.cc
Expand Up @@ -2306,9 +2306,8 @@ bool HeapObject::NeedsRehashing() const {
case TRANSITION_ARRAY_TYPE:
return TransitionArray::cast(*this).number_of_entries() > 1;
case ORDERED_HASH_MAP_TYPE:
return OrderedHashMap::cast(*this).NumberOfElements() > 0;
case ORDERED_HASH_SET_TYPE:
return OrderedHashSet::cast(*this).NumberOfElements() > 0;
return false; // We'll rehash from the JSMap or JSSet referencing them.
case NAME_DICTIONARY_TYPE:
case GLOBAL_DICTIONARY_TYPE:
case NUMBER_DICTIONARY_TYPE:
Expand All @@ -2318,6 +2317,8 @@ bool HeapObject::NeedsRehashing() const {
case SMALL_ORDERED_HASH_MAP_TYPE:
case SMALL_ORDERED_HASH_SET_TYPE:
case SMALL_ORDERED_NAME_DICTIONARY_TYPE:
case JS_MAP_TYPE:
case JS_SET_TYPE:
return true;
default:
return false;
Expand All @@ -2327,10 +2328,13 @@ bool HeapObject::NeedsRehashing() const {
bool HeapObject::CanBeRehashed() const {
DCHECK(NeedsRehashing());
switch (map().instance_type()) {
case JS_MAP_TYPE:
case JS_SET_TYPE:
return true;
case ORDERED_HASH_MAP_TYPE:
case ORDERED_HASH_SET_TYPE:
UNREACHABLE(); // We'll rehash from the JSMap or JSSet referencing them.
case ORDERED_NAME_DICTIONARY_TYPE:
// TODO(yangguo): actually support rehashing OrderedHash{Map,Set}.
return false;
case NAME_DICTIONARY_TYPE:
case GLOBAL_DICTIONARY_TYPE:
Expand All @@ -2354,7 +2358,8 @@ bool HeapObject::CanBeRehashed() const {
return false;
}

void HeapObject::RehashBasedOnMap(ReadOnlyRoots roots) {
void HeapObject::RehashBasedOnMap(Isolate* isolate) {
ReadOnlyRoots roots = ReadOnlyRoots(isolate);
switch (map().instance_type()) {
case HASH_TABLE_TYPE:
UNREACHABLE();
Expand Down Expand Up @@ -2386,6 +2391,17 @@ void HeapObject::RehashBasedOnMap(ReadOnlyRoots roots) {
case SMALL_ORDERED_HASH_SET_TYPE:
DCHECK_EQ(0, SmallOrderedHashSet::cast(*this).NumberOfElements());
break;
case ORDERED_HASH_MAP_TYPE:
case ORDERED_HASH_SET_TYPE:
UNREACHABLE(); // We'll rehash from the JSMap or JSSet referencing them.
case JS_MAP_TYPE: {
JSMap::cast(*this).Rehash(isolate);
break;
}
case JS_SET_TYPE: {
JSSet::cast(*this).Rehash(isolate);
break;
}
case SMALL_ORDERED_NAME_DICTIONARY_TYPE:
DCHECK_EQ(0, SmallOrderedNameDictionary::cast(*this).NumberOfElements());
break;
Expand Down Expand Up @@ -7852,6 +7868,13 @@ void JSSet::Clear(Isolate* isolate, Handle<JSSet> set) {
set->set_table(*table);
}

void JSSet::Rehash(Isolate* isolate) {
Handle<OrderedHashSet> table_handle(OrderedHashSet::cast(table()), isolate);
Handle<OrderedHashSet> new_table =
OrderedHashSet::Rehash(isolate, table_handle).ToHandleChecked();
set_table(*new_table);
}

void JSMap::Initialize(Handle<JSMap> map, Isolate* isolate) {
Handle<OrderedHashMap> table = isolate->factory()->NewOrderedHashMap();
map->set_table(*table);
Expand All @@ -7863,6 +7886,13 @@ void JSMap::Clear(Isolate* isolate, Handle<JSMap> map) {
map->set_table(*table);
}

void JSMap::Rehash(Isolate* isolate) {
Handle<OrderedHashMap> table_handle(OrderedHashMap::cast(table()), isolate);
Handle<OrderedHashMap> new_table =
OrderedHashMap::Rehash(isolate, table_handle).ToHandleChecked();
set_table(*new_table);
}

void JSWeakCollection::Initialize(Handle<JSWeakCollection> weak_collection,
Isolate* isolate) {
Handle<EphemeronHashTable> table = EphemeronHashTable::New(isolate, 0);
Expand Down
21 changes: 21 additions & 0 deletions deps/v8/src/objects/ordered-hash-table.cc
Expand Up @@ -194,6 +194,13 @@ HeapObject OrderedHashMap::GetEmpty(ReadOnlyRoots ro_roots) {
return ro_roots.empty_ordered_hash_map();
}

template <class Derived, int entrysize>
MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Rehash(
Isolate* isolate, Handle<Derived> table) {
return OrderedHashTable<Derived, entrysize>::Rehash(isolate, table,
table->Capacity());
}

template <class Derived, int entrysize>
MaybeHandle<Derived> OrderedHashTable<Derived, entrysize>::Rehash(
Isolate* isolate, Handle<Derived> table, int new_capacity) {
Expand Down Expand Up @@ -250,6 +257,20 @@ MaybeHandle<OrderedHashSet> OrderedHashSet::Rehash(Isolate* isolate,
new_capacity);
}

MaybeHandle<OrderedHashSet> OrderedHashSet::Rehash(
Isolate* isolate, Handle<OrderedHashSet> table) {
return OrderedHashTable<
OrderedHashSet, OrderedHashSet::kEntrySizeWithoutChain>::Rehash(isolate,
table);
}

MaybeHandle<OrderedHashMap> OrderedHashMap::Rehash(
Isolate* isolate, Handle<OrderedHashMap> table) {
return OrderedHashTable<
OrderedHashMap, OrderedHashMap::kEntrySizeWithoutChain>::Rehash(isolate,
table);
}

MaybeHandle<OrderedHashMap> OrderedHashMap::Rehash(Isolate* isolate,
Handle<OrderedHashMap> table,
int new_capacity) {
Expand Down
7 changes: 7 additions & 0 deletions deps/v8/src/objects/ordered-hash-table.h
Expand Up @@ -138,6 +138,7 @@ class OrderedHashTable : public FixedArray {

// The extra +1 is for linking the bucket chains together.
static const int kEntrySize = entrysize + 1;
static const int kEntrySizeWithoutChain = entrysize;
static const int kChainOffset = entrysize;

static const int kNotFound = -1;
Expand Down Expand Up @@ -200,6 +201,8 @@ class OrderedHashTable : public FixedArray {
static MaybeHandle<Derived> Allocate(
Isolate* isolate, int capacity,
AllocationType allocation = AllocationType::kYoung);

static MaybeHandle<Derived> Rehash(Isolate* isolate, Handle<Derived> table);
static MaybeHandle<Derived> Rehash(Isolate* isolate, Handle<Derived> table,
int new_capacity);

Expand Down Expand Up @@ -244,6 +247,8 @@ class V8_EXPORT_PRIVATE OrderedHashSet
static MaybeHandle<OrderedHashSet> Rehash(Isolate* isolate,
Handle<OrderedHashSet> table,
int new_capacity);
static MaybeHandle<OrderedHashSet> Rehash(Isolate* isolate,
Handle<OrderedHashSet> table);
static MaybeHandle<OrderedHashSet> Allocate(
Isolate* isolate, int capacity,
AllocationType allocation = AllocationType::kYoung);
Expand Down Expand Up @@ -273,6 +278,8 @@ class V8_EXPORT_PRIVATE OrderedHashMap
static MaybeHandle<OrderedHashMap> Rehash(Isolate* isolate,
Handle<OrderedHashMap> table,
int new_capacity);
static MaybeHandle<OrderedHashMap> Rehash(Isolate* isolate,
Handle<OrderedHashMap> table);
Object ValueAt(int entry);

// This takes and returns raw Address values containing tagged Object
Expand Down
2 changes: 1 addition & 1 deletion deps/v8/src/snapshot/context-deserializer.cc
Expand Up @@ -59,12 +59,12 @@ MaybeHandle<Object> ContextDeserializer::Deserialize(
// new code, which also has to be flushed from instruction cache.
CHECK_EQ(start_address, code_space->top());

if (FLAG_rehash_snapshot && can_rehash()) Rehash();
LogNewMapEvents();

result = handle(root, isolate);
}

if (FLAG_rehash_snapshot && can_rehash()) Rehash();
SetupOffHeapArrayBufferBackingStores();

return result;
Expand Down
16 changes: 14 additions & 2 deletions deps/v8/src/snapshot/deserializer.cc
Expand Up @@ -82,7 +82,7 @@ void Deserializer::Initialize(Isolate* isolate) {
void Deserializer::Rehash() {
DCHECK(can_rehash() || deserializing_user_code());
for (HeapObject item : to_rehash_) {
item.RehashBasedOnMap(ReadOnlyRoots(isolate_));
item.RehashBasedOnMap(isolate_);
}
}

Expand Down Expand Up @@ -142,6 +142,14 @@ void Deserializer::DeserializeDeferredObjects() {
}
}
}

// When the deserialization of maps are deferred, they will be created
// as filler maps, and we postpone the post processing until the maps
// are also deserialized.
for (const auto& pair : fillers_to_post_process_) {
DCHECK(!pair.first.IsFiller());
PostProcessNewObject(pair.first, pair.second);
}
}

void Deserializer::LogNewObjectEvents() {
Expand Down Expand Up @@ -213,7 +221,11 @@ HeapObject Deserializer::PostProcessNewObject(HeapObject obj,
DisallowHeapAllocation no_gc;

if ((FLAG_rehash_snapshot && can_rehash_) || deserializing_user_code()) {
if (obj.IsString()) {
if (obj.IsFiller()) {
DCHECK_EQ(fillers_to_post_process_.find(obj),
fillers_to_post_process_.end());
fillers_to_post_process_.insert({obj, space});
} else if (obj.IsString()) {
// Uninitialize hash field as we need to recompute the hash.
String string = String::cast(obj);
string.set_hash_field(String::kEmptyHashField);
Expand Down
5 changes: 5 additions & 0 deletions deps/v8/src/snapshot/deserializer.h
Expand Up @@ -197,6 +197,11 @@ class V8_EXPORT_PRIVATE Deserializer : public SerializerDeserializer {
// TODO(6593): generalize rehashing, and remove this flag.
bool can_rehash_;
std::vector<HeapObject> to_rehash_;
// Store the objects whose maps are deferred and thus initialized as filler
// maps during deserialization, so that they can be processed later when the
// maps become available.
std::unordered_map<HeapObject, SnapshotSpace, Object::Hasher>
fillers_to_post_process_;

#ifdef DEBUG
uint32_t num_api_references_;
Expand Down
2 changes: 1 addition & 1 deletion deps/v8/src/snapshot/object-deserializer.cc
Expand Up @@ -47,9 +47,9 @@ MaybeHandle<HeapObject> ObjectDeserializer::Deserialize(Isolate* isolate) {
LinkAllocationSites();
LogNewMapEvents();
result = handle(HeapObject::cast(root), isolate);
Rehash();
allocator()->RegisterDeserializedObjectsForBlackAllocation();
}
Rehash();
CommitPostProcessedObjects();
return scope.CloseAndEscape(result);
}
Expand Down
17 changes: 12 additions & 5 deletions deps/v8/test/cctest/test-serialize.cc
Expand Up @@ -3755,7 +3755,7 @@ UNINITIALIZED_TEST(SnapshotCreatorIncludeGlobalProxy) {
FreeCurrentEmbeddedBlob();
}

UNINITIALIZED_TEST(ReinitializeHashSeedNotRehashable) {
UNINITIALIZED_TEST(ReinitializeHashSeedJSCollectionRehashable) {
DisableAlwaysOpt();
i::FLAG_rehash_snapshot = true;
i::FLAG_hash_seed = 42;
Expand All @@ -3773,13 +3773,18 @@ UNINITIALIZED_TEST(ReinitializeHashSeedNotRehashable) {
CompileRun(
"var m = new Map();"
"m.set('a', 1);"
"m.set('b', 2);");
"m.set('b', 2);"
"var s = new Set();"
"s.add(1);"
"s.add(globalThis);");
ExpectInt32("m.get('b')", 2);
ExpectTrue("s.has(1)");
ExpectTrue("s.has(globalThis)");
creator.SetDefaultContext(context);
}
blob =
creator.CreateBlob(v8::SnapshotCreator::FunctionCodeHandling::kClear);
CHECK(!blob.CanBeRehashed());
CHECK(blob.CanBeRehashed());
}

i::FLAG_hash_seed = 1337;
Expand All @@ -3788,15 +3793,17 @@ UNINITIALIZED_TEST(ReinitializeHashSeedNotRehashable) {
create_params.snapshot_blob = &blob;
v8::Isolate* isolate = v8::Isolate::New(create_params);
{
// Check that no rehashing has been performed.
CHECK_EQ(static_cast<uint64_t>(42),
// Check that rehashing has been performed.
CHECK_EQ(static_cast<uint64_t>(1337),
HashSeed(reinterpret_cast<i::Isolate*>(isolate)));
v8::Isolate::Scope isolate_scope(isolate);
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Context> context = v8::Context::New(isolate);
CHECK(!context.IsEmpty());
v8::Context::Scope context_scope(context);
ExpectInt32("m.get('b')", 2);
ExpectTrue("s.has(1)");
ExpectTrue("s.has(globalThis)");
}
isolate->Dispose();
delete[] blob.data;
Expand Down

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