src/bootstrapper.h

// Copyright 2006-2008 the V8 project authors. All rights reserved.
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#ifndef V8_BOOTSTRAPPER_H_
#define V8_BOOTSTRAPPER_H_

namespace v8 {
namespace internal {


class BootstrapperActive BASE_EMBEDDED {
 public:
  BootstrapperActive() { nesting_++; }
  ~BootstrapperActive() { nesting_--; }

  // Support for thread preemption.
  static int ArchiveSpacePerThread();
  static char* ArchiveState(char* to);
  static char* RestoreState(char* from);

 private:
  static bool IsActive() { return nesting_ != 0; }
  static int nesting_;
  friend class Bootstrapper;
};


// The Boostrapper is the public interface for creating a JavaScript global
// context.
class Bootstrapper : public AllStatic {
 public:
  // Requires: Heap::Setup has been called.
  static void Initialize(bool create_heap_objects);
  static void TearDown();

  // Creates a JavaScript Global Context with initial object graph.
  // The returned value is a global handle casted to V8Environment*.
  static Handle<Context> CreateEnvironment(
      Handle<Object> global_object,
      v8::Handle<v8::ObjectTemplate> global_template,
      v8::ExtensionConfiguration* extensions);

  // Detach the environment from its outer global object.
  static void DetachGlobal(Handle<Context> env);

  // Reattach an outer global object to an environment.
  static void ReattachGlobal(Handle<Context> env, Handle<Object> global_object);

  // Traverses the pointers for memory management.
  static void Iterate(ObjectVisitor* v);

  // Accessors for the native scripts cache. Used in lazy loading.
  static Handle<String> NativesSourceLookup(int index);

  // Tells whether bootstrapping is active.
  static bool IsActive() { return BootstrapperActive::IsActive(); }

  // Encoding/decoding support for fixup flags.
  class FixupFlagsUseCodeObject: public BitField<bool, 0, 1> {};
  class FixupFlagsArgumentsCount: public BitField<uint32_t, 1, 32-1> {};

  // Support for thread preemption.
  static int ArchiveSpacePerThread();
  static char* ArchiveState(char* to);
  static char* RestoreState(char* from);
  static void FreeThreadResources();

  // This will allocate a char array that is deleted when V8 is shut down.
  // It should only be used for strictly finite allocations.
  static char* AllocateAutoDeletedArray(int bytes);

  // Used for new context creation.
  static bool InstallExtensions(Handle<Context> global_context,
                                v8::ExtensionConfiguration* extensions);
};


class NativesExternalStringResource
    : public v8::String::ExternalAsciiStringResource {
 public:
  explicit NativesExternalStringResource(const char* source);

  const char* data() const {
    return data_;
  }

  size_t length() const {
    return length_;
  }
 private:
  const char* data_;
  size_t length_;
};

}}  // namespace v8::internal

#endif  // V8_BOOTSTRAPPER_H_