1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
|
// Copyright 2016 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/snapshot/partial-serializer.h"
#include "src/snapshot/startup-serializer.h"
#include "src/objects-inl.h"
namespace v8 {
namespace internal {
PartialSerializer::PartialSerializer(
Isolate* isolate, StartupSerializer* startup_serializer,
v8::SerializeInternalFieldsCallback callback)
: Serializer(isolate),
startup_serializer_(startup_serializer),
serialize_internal_fields_(callback) {
InitializeCodeAddressMap();
}
PartialSerializer::~PartialSerializer() {
OutputStatistics("PartialSerializer");
}
void PartialSerializer::Serialize(Object** o) {
if ((*o)->IsContext()) {
Context* context = Context::cast(*o);
reference_map()->AddAttachedReference(context->global_proxy());
// The bootstrap snapshot has a code-stub context. When serializing the
// partial snapshot, it is chained into the weak context list on the isolate
// and it's next context pointer may point to the code-stub context. Clear
// it before serializing, it will get re-added to the context list
// explicitly when it's loaded.
if (context->IsNativeContext()) {
context->set(Context::NEXT_CONTEXT_LINK,
isolate_->heap()->undefined_value());
DCHECK(!context->global_object()->IsUndefined(context->GetIsolate()));
// Reset math random cache to get fresh random numbers.
context->set_math_random_index(Smi::kZero);
context->set_math_random_cache(isolate_->heap()->undefined_value());
}
}
VisitPointer(o);
SerializeDeferredObjects();
SerializeInternalFields();
Pad();
}
void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
WhereToPoint where_to_point, int skip) {
if (obj->IsMap()) {
// The code-caches link to context-specific code objects, which
// the startup and context serializes cannot currently handle.
DCHECK(Map::cast(obj)->code_cache() == obj->GetHeap()->empty_fixed_array());
}
// Replace typed arrays by undefined.
if (obj->IsJSTypedArray()) obj = isolate_->heap()->undefined_value();
if (SerializeHotObject(obj, how_to_code, where_to_point, skip)) return;
int root_index = root_index_map_.Lookup(obj);
if (root_index != RootIndexMap::kInvalidRootIndex) {
PutRoot(root_index, obj, how_to_code, where_to_point, skip);
return;
}
if (SerializeBackReference(obj, how_to_code, where_to_point, skip)) return;
if (ShouldBeInThePartialSnapshotCache(obj)) {
FlushSkip(skip);
int cache_index = startup_serializer_->PartialSnapshotCacheIndex(obj);
sink_.Put(kPartialSnapshotCache + how_to_code + where_to_point,
"PartialSnapshotCache");
sink_.PutInt(cache_index, "partial_snapshot_cache_index");
return;
}
// Pointers from the partial snapshot to the objects in the startup snapshot
// should go through the root array or through the partial snapshot cache.
// If this is not the case you may have to add something to the root array.
DCHECK(!startup_serializer_->reference_map()->Lookup(obj).is_valid());
// All the internalized strings that the partial snapshot needs should be
// either in the root table or in the partial snapshot cache.
DCHECK(!obj->IsInternalizedString());
// Function and object templates are not context specific.
DCHECK(!obj->IsTemplateInfo());
FlushSkip(skip);
// Clear literal boilerplates.
if (obj->IsJSFunction()) {
JSFunction* function = JSFunction::cast(obj);
LiteralsArray* literals = function->literals();
for (int i = 0; i < literals->literals_count(); i++) {
literals->set_literal_undefined(i);
}
function->ClearTypeFeedbackInfo();
}
if (obj->IsJSObject()) {
JSObject* jsobj = JSObject::cast(obj);
if (jsobj->GetInternalFieldCount() > 0) internal_field_holders_.Add(jsobj);
}
// Object has not yet been serialized. Serialize it here.
ObjectSerializer serializer(this, obj, &sink_, how_to_code, where_to_point);
serializer.Serialize();
}
bool PartialSerializer::ShouldBeInThePartialSnapshotCache(HeapObject* o) {
// Scripts should be referred only through shared function infos. We can't
// allow them to be part of the partial snapshot because they contain a
// unique ID, and deserializing several partial snapshots containing script
// would cause dupes.
DCHECK(!o->IsScript());
return o->IsName() || o->IsSharedFunctionInfo() || o->IsHeapNumber() ||
o->IsCode() || o->IsScopeInfo() || o->IsAccessorInfo() ||
o->IsTemplateInfo() ||
o->map() ==
startup_serializer_->isolate()->heap()->fixed_cow_array_map();
}
void PartialSerializer::SerializeInternalFields() {
int count = internal_field_holders_.length();
if (count == 0) return;
DisallowHeapAllocation no_gc;
DisallowJavascriptExecution no_js(isolate());
DisallowCompilation no_compile(isolate());
DCHECK_NOT_NULL(serialize_internal_fields_);
sink_.Put(kInternalFieldsData, "internal fields data");
while (internal_field_holders_.length() > 0) {
HandleScope scope(isolate());
Handle<JSObject> obj(internal_field_holders_.RemoveLast(), isolate());
SerializerReference reference = reference_map_.Lookup(*obj);
DCHECK(reference.is_back_reference());
int internal_fields_count = obj->GetInternalFieldCount();
for (int i = 0; i < internal_fields_count; i++) {
if (obj->GetInternalField(i)->IsHeapObject()) continue;
StartupData data = serialize_internal_fields_(v8::Utils::ToLocal(obj), i);
sink_.Put(kNewObject + reference.space(), "internal field holder");
PutBackReference(*obj, reference);
sink_.PutInt(i, "internal field index");
sink_.PutInt(data.raw_size, "internal fields data size");
sink_.PutRaw(reinterpret_cast<const byte*>(data.data), data.raw_size,
"internal fields data");
delete[] data.data;
}
}
sink_.Put(kSynchronize, "Finished with internal fields data");
}
} // namespace internal
} // namespace v8
|
