src/hotspot/share/oops/accessDecorators.hpp

*** 198,230 ****
  // == Arraycopy Decorators ==
  // * ARRAYCOPY_CHECKCAST: This property means that the class of the objects in source
  //   are not guaranteed to be subclasses of the class of the destination array. This requires
  //   a check-cast barrier during the copying operation. If this is not set, it is assumed
  //   that the array is covariant: (the source array type is-a destination array type)
  // * ARRAYCOPY_DISJOINT: This property means that it is known that the two array ranges
  //   are disjoint.
  // * ARRAYCOPY_ARRAYOF: The copy is in the arrayof form.
  // * ARRAYCOPY_ATOMIC: The accesses have to be atomic over the size of its elements.
  // * ARRAYCOPY_ALIGNED: The accesses have to be aligned on a HeapWord.
  const DecoratorSet ARRAYCOPY_CHECKCAST            = UCONST64(1) << 24;
! const DecoratorSet ARRAYCOPY_DISJOINT             = UCONST64(1) << 25;
! const DecoratorSet ARRAYCOPY_ARRAYOF              = UCONST64(1) << 26;
! const DecoratorSet ARRAYCOPY_ATOMIC               = UCONST64(1) << 27;
! const DecoratorSet ARRAYCOPY_ALIGNED              = UCONST64(1) << 28;
! const DecoratorSet ARRAYCOPY_DECORATOR_MASK       = ARRAYCOPY_CHECKCAST | ARRAYCOPY_DISJOINT |
!                                                     ARRAYCOPY_DISJOINT | ARRAYCOPY_ARRAYOF |
!                                                     ARRAYCOPY_ATOMIC | ARRAYCOPY_ALIGNED;
  
  // == Resolve barrier decorators ==
  // * ACCESS_READ: Indicate that the resolved object is accessed read-only. This allows the GC
  //   backend to use weaker and more efficient barriers.
  // * ACCESS_WRITE: Indicate that the resolved object is used for write access.
! const DecoratorSet ACCESS_READ                    = UCONST64(1) << 29;
! const DecoratorSet ACCESS_WRITE                   = UCONST64(1) << 30;
  
  // Keep track of the last decorator.
! const DecoratorSet DECORATOR_LAST = UCONST64(1) << 30;
  
  namespace AccessInternal {
    // This class adds implied decorators that follow according to decorator rules.
    // For example adding default reference strength and default memory ordering
    // semantics.
--- 198,234 ----
  // == Arraycopy Decorators ==
  // * ARRAYCOPY_CHECKCAST: This property means that the class of the objects in source
  //   are not guaranteed to be subclasses of the class of the destination array. This requires
  //   a check-cast barrier during the copying operation. If this is not set, it is assumed
  //   that the array is covariant: (the source array type is-a destination array type)
+ // * ARRAYCOPY_NOTNULL: This property means that the source array may contain null elements
+ //   but the destination does not allow null elements (i.e. throw NPE)
  // * ARRAYCOPY_DISJOINT: This property means that it is known that the two array ranges
  //   are disjoint.
  // * ARRAYCOPY_ARRAYOF: The copy is in the arrayof form.
  // * ARRAYCOPY_ATOMIC: The accesses have to be atomic over the size of its elements.
  // * ARRAYCOPY_ALIGNED: The accesses have to be aligned on a HeapWord.
  const DecoratorSet ARRAYCOPY_CHECKCAST            = UCONST64(1) << 24;
! const DecoratorSet ARRAYCOPY_NOTNULL              = UCONST64(1) << 25;
! const DecoratorSet ARRAYCOPY_DISJOINT             = UCONST64(1) << 26;
! const DecoratorSet ARRAYCOPY_ARRAYOF              = UCONST64(1) << 27;
! const DecoratorSet ARRAYCOPY_ATOMIC               = UCONST64(1) << 28;
! const DecoratorSet ARRAYCOPY_ALIGNED              = UCONST64(1) << 29;
! const DecoratorSet ARRAYCOPY_DECORATOR_MASK       = ARRAYCOPY_CHECKCAST | ARRAYCOPY_NOTNULL |
!                                                     ARRAYCOPY_DISJOINT | ARRAYCOPY_DISJOINT |
!                                                     ARRAYCOPY_ARRAYOF | ARRAYCOPY_ATOMIC |
!                                                     ARRAYCOPY_ALIGNED;
  
  // == Resolve barrier decorators ==
  // * ACCESS_READ: Indicate that the resolved object is accessed read-only. This allows the GC
  //   backend to use weaker and more efficient barriers.
  // * ACCESS_WRITE: Indicate that the resolved object is used for write access.
! const DecoratorSet ACCESS_READ                    = UCONST64(1) << 30;
! const DecoratorSet ACCESS_WRITE                   = UCONST64(1) << 31;
  
  // Keep track of the last decorator.
! const DecoratorSet DECORATOR_LAST = UCONST64(1) << 31;
  
  namespace AccessInternal {
    // This class adds implied decorators that follow according to decorator rules.
    // For example adding default reference strength and default memory ordering
    // semantics.