Line data    Source code

       1             : // Copyright 2017 the V8 project authors. All rights reserved.
       2             : // Use of this source code is governed by a BSD-style license that can be
       3             : // found in the LICENSE file.
       4             : 
       5             : #ifndef V8_SNAPSHOT_BUILTIN_DESERIALIZER_H_
       6             : #define V8_SNAPSHOT_BUILTIN_DESERIALIZER_H_
       7             : 
       8             : #include "src/snapshot/builtin-deserializer-allocator.h"
       9             : #include "src/snapshot/deserializer.h"
      10             : 
      11             : namespace v8 {
      12             : namespace internal {
      13             : 
      14             : class BuiltinSnapshotData;
      15             : 
      16             : // Deserializes the builtins blob.
      17      155730 : class BuiltinDeserializer final
      18             :     : public Deserializer<BuiltinDeserializerAllocator> {
      19             :  public:
      20             :   BuiltinDeserializer(Isolate* isolate, const BuiltinSnapshotData* data);
      21             : 
      22             :   // Builtins deserialization is tightly integrated with deserialization of the
      23             :   // startup blob. In particular, we need to ensure that no GC can occur
      24             :   // between startup- and builtins deserialization, as all builtins have been
      25             :   // pre-allocated and their pointers may not be invalidated.
      26             :   //
      27             :   // After this, the instruction cache must be flushed by the caller (we don't
      28             :   // do it ourselves since the startup serializer batch-flushes all code pages).
      29             :   void DeserializeEagerBuiltins();
      30             : 
      31             :   // Deserializes the single given builtin. This is used whenever a builtin is
      32             :   // lazily deserialized at runtime.
      33             :   Code* DeserializeBuiltin(int builtin_id);
      34             : 
      35             :  private:
      36             :   // Deserializes the single given builtin. Assumes that reservations have
      37             :   // already been allocated.
      38             :   Code* DeserializeBuiltinRaw(int builtin_id);
      39             : 
      40             : 
      41             :   // Extracts the size builtin Code objects (baked into the snapshot).
      42             :   uint32_t ExtractBuiltinSize(int builtin_id);
      43             : 
      44             :   // BuiltinDeserializer implements its own builtin iteration logic. Make sure
      45             :   // the RootVisitor API is not used accidentally.
      46           0 :   void VisitRootPointers(Root root, Object** start, Object** end) override {
      47           0 :     UNREACHABLE();
      48             :   }
      49             : 
      50             :   int CurrentBuiltinId() const { return current_builtin_id_; }
      51             : 
      52             :  private:
      53             :   // Stores the builtin currently being deserialized. We need this to determine
      54             :   // where to 'allocate' from during deserialization.
      55             :   static const int kNoBuiltinId = -1;
      56             :   int current_builtin_id_ = kNoBuiltinId;
      57             : 
      58             :   // The offsets of each builtin within the serialized data. Equivalent to
      59             :   // BuiltinSerializer::builtin_offsets_ but on the deserialization side.
      60             :   Vector<const uint32_t> builtin_offsets_;
      61             : 
      62             :   // For current_builtin_id_.
      63             :   friend class DeserializingBuiltinScope;
      64             : 
      65             :   // For isolate(), IsLazyDeserializationEnabled(), CurrentBuiltinId() and
      66             :   // ExtractBuiltinSize().
      67             :   friend class BuiltinDeserializerAllocator;
      68             : };
      69             : 
      70             : }  // namespace internal
      71             : }  // namespace v8
      72             : 
      73             : #endif  // V8_SNAPSHOT_BUILTIN_DESERIALIZER_H_