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      1 // Copyright 2006-2008 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 
     29 #ifndef V8_BOOTSTRAPPER_H_
     30 #define V8_BOOTSTRAPPER_H_
     31 
     32 namespace v8 {
     33 namespace internal {
     34 
     35 
     36 class BootstrapperActive BASE_EMBEDDED {
     37  public:
     38   BootstrapperActive() { nesting_++; }
     39   ~BootstrapperActive() { nesting_--; }
     40 
     41   // Support for thread preemption.
     42   static int ArchiveSpacePerThread();
     43   static char* ArchiveState(char* to);
     44   static char* RestoreState(char* from);
     45 
     46  private:
     47   static bool IsActive() { return nesting_ != 0; }
     48   static int nesting_;
     49   friend class Bootstrapper;
     50 };
     51 
     52 
     53 // The Boostrapper is the public interface for creating a JavaScript global
     54 // context.
     55 class Bootstrapper : public AllStatic {
     56  public:
     57   // Requires: Heap::Setup has been called.
     58   static void Initialize(bool create_heap_objects);
     59   static void TearDown();
     60 
     61   // Creates a JavaScript Global Context with initial object graph.
     62   // The returned value is a global handle casted to V8Environment*.
     63   static Handle<Context> CreateEnvironment(
     64       Handle<Object> global_object,
     65       v8::Handle<v8::ObjectTemplate> global_template,
     66       v8::ExtensionConfiguration* extensions);
     67 
     68   // Detach the environment from its outer global object.
     69   static void DetachGlobal(Handle<Context> env);
     70 
     71   // Reattach an outer global object to an environment.
     72   static void ReattachGlobal(Handle<Context> env, Handle<Object> global_object);
     73 
     74   // Traverses the pointers for memory management.
     75   static void Iterate(ObjectVisitor* v);
     76 
     77   // Accessors for the native scripts cache. Used in lazy loading.
     78   static Handle<String> NativesSourceLookup(int index);
     79 
     80   // Tells whether bootstrapping is active.
     81   static bool IsActive() { return BootstrapperActive::IsActive(); }
     82 
     83   // Encoding/decoding support for fixup flags.
     84   class FixupFlagsUseCodeObject: public BitField<bool, 0, 1> {};
     85   class FixupFlagsArgumentsCount: public BitField<uint32_t, 1, 32-1> {};
     86 
     87   // Support for thread preemption.
     88   static int ArchiveSpacePerThread();
     89   static char* ArchiveState(char* to);
     90   static char* RestoreState(char* from);
     91   static void FreeThreadResources();
     92 
     93   // This will allocate a char array that is deleted when V8 is shut down.
     94   // It should only be used for strictly finite allocations.
     95   static char* AllocateAutoDeletedArray(int bytes);
     96 
     97   // Used for new context creation.
     98   static bool InstallExtensions(Handle<Context> global_context,
     99                                 v8::ExtensionConfiguration* extensions);
    100 };
    101 
    102 
    103 class NativesExternalStringResource
    104     : public v8::String::ExternalAsciiStringResource {
    105  public:
    106   explicit NativesExternalStringResource(const char* source);
    107 
    108   const char* data() const {
    109     return data_;
    110   }
    111 
    112   size_t length() const {
    113     return length_;
    114   }
    115  private:
    116   const char* data_;
    117   size_t length_;
    118 };
    119 
    120 }}  // namespace v8::internal
    121 
    122 #endif  // V8_BOOTSTRAPPER_H_
    123