src/share/vm/runtime/virtualspace.hpp

rev 7462 : 8064457: Introduce compressed oops mode disjoint base and improve compressed heap handling.

*** 29,65 ****
  
  // ReservedSpace is a data structure for reserving a contiguous address range.
  
  class ReservedSpace VALUE_OBJ_CLASS_SPEC {
    friend class VMStructs;
!  private:
    char*  _base;
    size_t _size;
    size_t _noaccess_prefix;
    size_t _alignment;
    bool   _special;
    bool   _executable;
  
    // ReservedSpace
    ReservedSpace(char* base, size_t size, size_t alignment, bool special,
                  bool executable);
    void initialize(size_t size, size_t alignment, bool large,
                    char* requested_address,
-                   const size_t noaccess_prefix,
                    bool executable);
- 
-  protected:
    // Create protection page at the beginning of the space.
!   void protect_noaccess_prefix(const size_t size);
  
   public:
    // Constructor
    ReservedSpace();
    ReservedSpace(size_t size);
    ReservedSpace(size_t size, size_t alignment, bool large,
!                 char* requested_address = NULL,
!                 const size_t noaccess_prefix = 0);
    ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
  
    // Accessors
    char*  base()            const { return _base;      }
    size_t size()            const { return _size;      }
--- 29,63 ----
  
  // ReservedSpace is a data structure for reserving a contiguous address range.
  
  class ReservedSpace VALUE_OBJ_CLASS_SPEC {
    friend class VMStructs;
!  protected:
    char*  _base;
    size_t _size;
    size_t _noaccess_prefix;
    size_t _alignment;
    bool   _special;
+  private:
    bool   _executable;
  
    // ReservedSpace
    ReservedSpace(char* base, size_t size, size_t alignment, bool special,
                  bool executable);
+  protected:
    void initialize(size_t size, size_t alignment, bool large,
                    char* requested_address,
                    bool executable);
    // Create protection page at the beginning of the space.
!   void establish_noaccess_prefix();
  
   public:
    // Constructor
    ReservedSpace();
    ReservedSpace(size_t size);
    ReservedSpace(size_t size, size_t alignment, bool large,
!                 char* requested_address = NULL);
    ReservedSpace(size_t size, size_t alignment, bool large, bool executable);
  
    // Accessors
    char*  base()            const { return _base;      }
    size_t size()            const { return _size;      }
*** 96,111 ****
  ReservedSpace ReservedSpace::last_part(size_t partition_size)
  {
    return last_part(partition_size, alignment());
  }
  
! // Class encapsulating behavior specific of memory space reserved for Java heap
  class ReservedHeapSpace : public ReservedSpace {
! public:
!   // Constructor
!   ReservedHeapSpace(size_t size, size_t forced_base_alignment,
!                     bool large, char* requested_address);
  };
  
  // Class encapsulating behavior specific memory space for Code
  class ReservedCodeSpace : public ReservedSpace {
   public:
--- 94,116 ----
  ReservedSpace ReservedSpace::last_part(size_t partition_size)
  {
    return last_part(partition_size, alignment());
  }
  
! // Class encapsulating behavior specific of memory space reserved for Java heap.
  class ReservedHeapSpace : public ReservedSpace {
!  private:
!   void try_reserve_heap(size_t size, size_t alignment, bool large, char* requested_address);
!   void try_reserve_range(char *const highest_start, char *lowest_start, size_t attach_point_alignment,
!                          char *aligned_HBMA, char *upper_bound, size_t size, size_t alignment, bool large);
!   void initialize_compressed_heap(size_t size, size_t alignment, bool large);
!  public:
!   // Constructor. Tries to find a heap that is good for compressed oops.
!   ReservedHeapSpace(size_t size, size_t forced_base_alignment, bool large);
!   // Returns the base to be used for compression, i.e. so that null can be encoded safely and
!   // implicit null checks can work.
!   char *compressed_oop_base() { return _base - _noaccess_prefix; }
  };
  
  // Class encapsulating behavior specific memory space for Code
  class ReservedCodeSpace : public ReservedSpace {
   public: