| // Copyright 2006-2008 the V8 project authors. All rights reserved. |
| // Redistribution and use in source and binary forms, with or without |
| // modification, are permitted provided that the following conditions are |
| // met: |
| // |
| // * Redistributions of source code must retain the above copyright |
| // notice, this list of conditions and the following disclaimer. |
| // * Redistributions in binary form must reproduce the above |
| // copyright notice, this list of conditions and the following |
| // disclaimer in the documentation and/or other materials provided |
| // with the distribution. |
| // * Neither the name of Google Inc. nor the names of its |
| // contributors may be used to endorse or promote products derived |
| // from this software without specific prior written permission. |
| // |
| // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| #ifndef V8_SERIALIZE_H_ |
| #define V8_SERIALIZE_H_ |
| |
| #include "hashmap.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| // A TypeCode is used to distinguish different kinds of external reference. |
| // It is a single bit to make testing for types easy. |
| enum TypeCode { |
| UNCLASSIFIED, // One-of-a-kind references. |
| BUILTIN, |
| RUNTIME_FUNCTION, |
| IC_UTILITY, |
| DEBUG_ADDRESS, |
| STATS_COUNTER, |
| TOP_ADDRESS, |
| C_BUILTIN, |
| EXTENSION, |
| ACCESSOR, |
| RUNTIME_ENTRY, |
| STUB_CACHE_TABLE |
| }; |
| |
| const int kTypeCodeCount = STUB_CACHE_TABLE + 1; |
| const int kFirstTypeCode = UNCLASSIFIED; |
| |
| const int kReferenceIdBits = 16; |
| const int kReferenceIdMask = (1 << kReferenceIdBits) - 1; |
| const int kReferenceTypeShift = kReferenceIdBits; |
| const int kDebugRegisterBits = 4; |
| const int kDebugIdShift = kDebugRegisterBits; |
| |
| |
| class ExternalReferenceEncoder { |
| public: |
| ExternalReferenceEncoder(); |
| |
| uint32_t Encode(Address key) const; |
| |
| const char* NameOfAddress(Address key) const; |
| |
| private: |
| HashMap encodings_; |
| static uint32_t Hash(Address key) { |
| return static_cast<uint32_t>(reinterpret_cast<uintptr_t>(key) >> 2); |
| } |
| |
| int IndexOf(Address key) const; |
| |
| static bool Match(void* key1, void* key2) { return key1 == key2; } |
| |
| void Put(Address key, int index); |
| }; |
| |
| |
| class ExternalReferenceDecoder { |
| public: |
| ExternalReferenceDecoder(); |
| ~ExternalReferenceDecoder(); |
| |
| Address Decode(uint32_t key) const { |
| if (key == 0) return NULL; |
| return *Lookup(key); |
| } |
| |
| private: |
| Address** encodings_; |
| |
| Address* Lookup(uint32_t key) const { |
| int type = key >> kReferenceTypeShift; |
| ASSERT(kFirstTypeCode <= type && type < kTypeCodeCount); |
| int id = key & kReferenceIdMask; |
| return &encodings_[type][id]; |
| } |
| |
| void Put(uint32_t key, Address value) { |
| *Lookup(key) = value; |
| } |
| }; |
| |
| |
| // A Serializer recursively visits objects to construct a serialized |
| // representation of the Heap stored in a string. Serialization is |
| // destructive. We use a similar mechanism to the GC to ensure that |
| // each object is visited once, namely, we modify the map pointer of |
| // each visited object to contain the relative address in the |
| // appropriate space where that object will be allocated when the heap |
| // is deserialized. |
| |
| |
| // Helper classes defined in serialize.cc. |
| class RelativeAddress; |
| class SimulatedHeapSpace; |
| class SnapshotWriter; |
| class ReferenceUpdater; |
| |
| |
| class Serializer: public ObjectVisitor { |
| public: |
| Serializer(); |
| |
| virtual ~Serializer(); |
| |
| // Serialize the current state of the heap. This operation destroys the |
| // heap contents and the contents of the roots into the heap. |
| void Serialize(); |
| |
| // Returns the serialized buffer. Ownership is transferred to the |
| // caller. Only the destructor and getters may be called after this call. |
| void Finalize(byte** str, int* len); |
| |
| int roots() { return roots_; } |
| int objects() { return objects_; } |
| |
| #ifdef DEBUG |
| // insert "tag" into the serialized stream |
| virtual void Synchronize(const char* tag); |
| #endif |
| |
| static bool enabled() { return serialization_enabled_; } |
| |
| static void Enable() { serialization_enabled_ = true; } |
| static void Disable() { serialization_enabled_ = false; } |
| |
| private: |
| friend class ReferenceUpdater; |
| |
| virtual void VisitPointers(Object** start, Object** end); |
| |
| bool IsVisited(HeapObject* obj); |
| |
| Address GetSavedAddress(HeapObject* obj); |
| |
| void SaveAddress(HeapObject* obj, Address addr); |
| |
| void PutEncodedAddress(Address addr); |
| // Write the global flags into the file. |
| void PutFlags(); |
| // Write global information into the header of the file. |
| void PutHeader(); |
| // Write the contents of the log into the file. |
| void PutLog(); |
| // Serialize 'obj', and return its encoded RelativeAddress. |
| Address PutObject(HeapObject* obj); |
| // Write a stack of handles to the file bottom first. |
| void PutGlobalHandleStack(const List<Handle<Object> >& stack); |
| // Write the context stack into the file. |
| void PutContextStack(); |
| |
| // Return the encoded RelativeAddress where this object will be |
| // allocated on deserialization. On the first visit of 'o', |
| // serialize its contents. On return, *serialized will be true iff |
| // 'o' has just been serialized. |
| Address Encode(Object* o, bool* serialized); |
| |
| // Simulate the allocation of 'obj', returning the address where it will |
| // be allocated on deserialization |
| RelativeAddress Allocate(HeapObject* obj); |
| |
| void InitializeAllocators(); |
| |
| SnapshotWriter* writer_; |
| bool root_; // serializing a root? |
| int roots_; // number of roots visited |
| int objects_; // number of objects serialized |
| |
| static bool serialization_enabled_; |
| |
| int flags_end_; // The position right after the flags. |
| |
| // An array of per-space SimulatedHeapSpacees used as memory allocators. |
| SimulatedHeapSpace* allocator_[LAST_SPACE+1]; |
| // A list of global handles at serialization time. |
| List<Object**> global_handles_; |
| |
| ExternalReferenceEncoder* reference_encoder_; |
| |
| HashMap saved_addresses_; |
| |
| DISALLOW_COPY_AND_ASSIGN(Serializer); |
| }; |
| |
| // Helper class to read the bytes of the serialized heap. |
| |
| class SnapshotReader { |
| public: |
| SnapshotReader(const byte* str, int len): str_(str), end_(str + len) {} |
| |
| void ExpectC(char expected) { |
| int c = GetC(); |
| USE(c); |
| ASSERT(c == expected); |
| } |
| |
| int GetC() { |
| if (str_ >= end_) return EOF; |
| return *str_++; |
| } |
| |
| int GetInt() { |
| int result; |
| GetBytes(reinterpret_cast<Address>(&result), sizeof(result)); |
| return result; |
| } |
| |
| Address GetAddress() { |
| Address result; |
| GetBytes(reinterpret_cast<Address>(&result), sizeof(result)); |
| return result; |
| } |
| |
| void GetBytes(Address a, int size) { |
| ASSERT(str_ + size <= end_); |
| memcpy(a, str_, size); |
| str_ += size; |
| } |
| |
| char* GetString() { |
| ExpectC('['); |
| int size = GetInt(); |
| ExpectC(']'); |
| char* s = NewArray<char>(size + 1); |
| GetBytes(reinterpret_cast<Address>(s), size); |
| s[size] = 0; |
| return s; |
| } |
| |
| private: |
| const byte* str_; |
| const byte* end_; |
| }; |
| |
| |
| // A Deserializer reads a snapshot and reconstructs the Object graph it defines. |
| |
| class Deserializer: public ObjectVisitor { |
| public: |
| // Create a deserializer. The snapshot is held in str and has size len. |
| Deserializer(const byte* str, int len); |
| |
| virtual ~Deserializer(); |
| |
| // Read the flags from the header of the file, and set those that |
| // should be inherited from the snapshot. |
| void GetFlags(); |
| |
| // Read saved profiling information from the file and log it if required. |
| void GetLog(); |
| |
| // Deserialize the snapshot into an empty heap. |
| void Deserialize(); |
| |
| int roots() { return roots_; } |
| int objects() { return objects_; } |
| |
| #ifdef DEBUG |
| // Check for the presence of "tag" in the serialized stream |
| virtual void Synchronize(const char* tag); |
| #endif |
| |
| private: |
| virtual void VisitPointers(Object** start, Object** end); |
| virtual void VisitExternalReferences(Address* start, Address* end); |
| virtual void VisitRuntimeEntry(RelocInfo* rinfo); |
| |
| Address GetEncodedAddress(); |
| |
| // Read other global information (except flags) from the header of the file. |
| void GetHeader(); |
| // Read a stack of handles from the file bottom first. |
| void GetGlobalHandleStack(List<Handle<Object> >* stack); |
| // Read the context stack from the file. |
| void GetContextStack(); |
| |
| Object* GetObject(); |
| |
| // Get the encoded address. In debug mode we make sure |
| // it matches the given expectations. |
| void ExpectEncodedAddress(Address expected); |
| |
| // Given an encoded address (the result of |
| // RelativeAddress::Encode), return the object to which it points, |
| // which will be either an Smi or a HeapObject in the current heap. |
| Object* Resolve(Address encoded_address); |
| |
| SnapshotReader reader_; |
| bool root_; // Deserializing a root? |
| int roots_; // number of roots visited |
| int objects_; // number of objects serialized |
| |
| bool has_log_; // The file has log information. |
| |
| // Resolve caches the following: |
| List<Page*> map_pages_; // All pages in the map space. |
| List<Page*> old_pointer_pages_; // All pages in the old pointer space. |
| List<Page*> old_data_pages_; // All pages in the old data space. |
| List<Page*> code_pages_; |
| List<Object*> large_objects_; // All known large objects. |
| // A list of global handles at deserialization time. |
| List<Object**> global_handles_; |
| |
| ExternalReferenceDecoder* reference_decoder_; |
| |
| #ifdef DEBUG |
| bool expect_debug_information_; |
| #endif |
| |
| DISALLOW_COPY_AND_ASSIGN(Deserializer); |
| }; |
| |
| } } // namespace v8::internal |
| |
| #endif // V8_SERIALIZE_H_ |