26 #include "classfile/javaClasses.inline.hpp" |
26 #include "classfile/javaClasses.inline.hpp" |
27 #include "gc/shared/accessBarrierSupport.inline.hpp" |
27 #include "gc/shared/accessBarrierSupport.inline.hpp" |
28 #include "oops/access.hpp" |
28 #include "oops/access.hpp" |
29 |
29 |
30 DecoratorSet AccessBarrierSupport::resolve_unknown_oop_ref_strength(DecoratorSet decorators, oop base, ptrdiff_t offset) { |
30 DecoratorSet AccessBarrierSupport::resolve_unknown_oop_ref_strength(DecoratorSet decorators, oop base, ptrdiff_t offset) { |
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31 // Note that the referent in a FinalReference is technically not strong. |
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32 // However, it always behaves like one in practice. The two cases are: |
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33 // 1) A mutator calls Reference.get(). However, a mutator can only ever |
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34 // see inactive FinalReferences, whose referents really are strong. |
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35 // 2) A GC heap walking operation. In this case the GC can see active |
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36 // FinalReferences, but the GC always wants to follow the referent |
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37 // as if it was strong. |
31 DecoratorSet ds = decorators & ~ON_UNKNOWN_OOP_REF; |
38 DecoratorSet ds = decorators & ~ON_UNKNOWN_OOP_REF; |
32 if (!java_lang_ref_Reference::is_referent_field(base, offset)) { |
39 if (!java_lang_ref_Reference::is_referent_field(base, offset) || |
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40 java_lang_ref_Reference::is_final(base)) { |
33 ds |= ON_STRONG_OOP_REF; |
41 ds |= ON_STRONG_OOP_REF; |
34 } else if (java_lang_ref_Reference::is_phantom(base)) { |
42 } else if (java_lang_ref_Reference::is_phantom(base)) { |
35 ds |= ON_PHANTOM_OOP_REF; |
43 ds |= ON_PHANTOM_OOP_REF; |
36 } else { |
44 } else { |
37 ds |= ON_WEAK_OOP_REF; |
45 ds |= ON_WEAK_OOP_REF; |