[serializer] split up src/snapshot/serialize.*

src/snapshot/startup-serializer.cc

+// 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/startup-serializer.h"
+
+#include "src/objects-inl.h"
+#include "src/v8threads.h"
+
+namespace v8 {
+namespace internal {
+
+StartupSerializer::StartupSerializer(Isolate* isolate, SnapshotByteSink* sink)
+    : Serializer(isolate, sink),
+      root_index_wave_front_(0),
+      serializing_builtins_(false) {
+  // Clear the cache of objects used by the partial snapshot.  After the
+  // strong roots have been serialized we can create a partial snapshot
+  // which will repopulate the cache with objects needed by that partial
+  // snapshot.
+  isolate->partial_snapshot_cache()->Clear();
+  InitializeCodeAddressMap();
+}
+
+StartupSerializer::~StartupSerializer() {
+  OutputStatistics("StartupSerializer");
+}
+
+void StartupSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
+                                        WhereToPoint where_to_point, int skip) {
+  DCHECK(!obj->IsJSFunction());
+
+  if (obj->IsCode()) {
+    Code* code = Code::cast(obj);
+    // If the function code is compiled (either as native code or bytecode),
+    // replace it with lazy-compile builtin. Only exception is when we are
+    // serializing the canonical interpreter-entry-trampoline builtin.
+    if (code->kind() == Code::FUNCTION ||
+        (!serializing_builtins_ && code->is_interpreter_entry_trampoline())) {
+      obj = isolate()->builtins()->builtin(Builtins::kCompileLazy);
+    }
+  } else if (obj->IsBytecodeArray()) {
+    obj = isolate()->heap()->undefined_value();
+  }
+
+  int root_index = root_index_map_.Lookup(obj);
+  bool is_immortal_immovable_root = false;
+  // We can only encode roots as such if it has already been serialized.
+  // That applies to root indices below the wave front.
+  if (root_index != RootIndexMap::kInvalidRootIndex) {
+    if (root_index < root_index_wave_front_) {
+      PutRoot(root_index, obj, how_to_code, where_to_point, skip);
+      return;
+    } else {
+      is_immortal_immovable_root = Heap::RootIsImmortalImmovable(root_index);
+    }
+  }
+
+  if (SerializeKnownObject(obj, how_to_code, where_to_point, skip)) return;
+
+  FlushSkip(skip);
+
+  // Object has not yet been serialized.  Serialize it here.
+  ObjectSerializer object_serializer(this, obj, sink_, how_to_code,
+                                     where_to_point);
+  object_serializer.Serialize();
+
+  if (is_immortal_immovable_root) {
+    // Make sure that the immortal immovable root has been included in the first
+    // chunk of its reserved space , so that it is deserialized onto the first
+    // page of its space and stays immortal immovable.
+    BackReference ref = back_reference_map_.Lookup(obj);
+    CHECK(ref.is_valid() && ref.chunk_index() == 0);
+  }
+}
+
+void StartupSerializer::SerializeWeakReferencesAndDeferred() {
+  // This phase comes right after the serialization (of the snapshot).
+  // After we have done the partial serialization the partial snapshot cache
+  // will contain some references needed to decode the partial snapshot.  We
+  // add one entry with 'undefined' which is the sentinel that the deserializer
+  // uses to know it is done deserializing the array.
+  Object* undefined = isolate()->heap()->undefined_value();
+  VisitPointer(&undefined);
+  isolate()->heap()->IterateWeakRoots(this, VISIT_ALL);
+  SerializeDeferredObjects();
+  Pad();
+}
+
+void StartupSerializer::Synchronize(VisitorSynchronization::SyncTag tag) {
+  // We expect the builtins tag after builtins have been serialized.
+  DCHECK(!serializing_builtins_ || tag == VisitorSynchronization::kBuiltins);
+  serializing_builtins_ = (tag == VisitorSynchronization::kHandleScope);
+  sink_->Put(kSynchronize, "Synchronize");
+}
+
+void StartupSerializer::SerializeStrongReferences() {
+  Isolate* isolate = this->isolate();
+  // No active threads.
+  CHECK_NULL(isolate->thread_manager()->FirstThreadStateInUse());
+  // No active or weak handles.
+  CHECK(isolate->handle_scope_implementer()->blocks()->is_empty());
+  CHECK_EQ(0, isolate->global_handles()->NumberOfWeakHandles());
+  CHECK_EQ(0, isolate->eternal_handles()->NumberOfHandles());
+  // We don't support serializing installed extensions.
+  CHECK(!isolate->has_installed_extensions());
+  isolate->heap()->IterateSmiRoots(this);
+  isolate->heap()->IterateStrongRoots(this, VISIT_ONLY_STRONG);
+}
+
+void StartupSerializer::VisitPointers(Object** start, Object** end) {
+  for (Object** current = start; current < end; current++) {
+    if (start == isolate()->heap()->roots_array_start()) {
+      root_index_wave_front_ =
+          Max(root_index_wave_front_, static_cast<intptr_t>(current - start));
+    }
+    if (ShouldBeSkipped(current)) {
+      sink_->Put(kSkip, "Skip");
+      sink_->PutInt(kPointerSize, "SkipOneWord");
+    } else if ((*current)->IsSmi()) {
+      sink_->Put(kOnePointerRawData, "Smi");
+      for (int i = 0; i < kPointerSize; i++) {
+        sink_->Put(reinterpret_cast<byte*>(current)[i], "Byte");
+      }
+    } else {
+      SerializeObject(HeapObject::cast(*current), kPlain, kStartOfObject, 0);
+    }
+  }
+}
+
+}  // namespace internal
+}  // namespace v8