src/share/vm/classfile/metadataOnStackMark.hpp

rev 6875 : 8056240: Investigate increased GC remark time after class unloading changes in CRM Fuse
Reviewed-by: mgerdin, coleenp, bdelsart

*** 24,45 ****
  
  #ifndef SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
  #define SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
  
  #include "memory/allocation.hpp"
  
  class Metadata;
  
  // Helper class to mark and unmark metadata used on the stack as either handles
  // or executing methods, so that it can't be deleted during class redefinition
  // and class unloading.
  // This is also used for other things that can be deallocated, like class
  // metadata during parsing, relocated methods, and methods in backtraces.
  class MetadataOnStackMark : public StackObj {
    NOT_PRODUCT(static bool _is_active;)
   public:
!   MetadataOnStackMark();
    ~MetadataOnStackMark();
!   static void record(Metadata* m);
  };
  
  #endif // SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
--- 24,58 ----
  
  #ifndef SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
  #define SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP
  
  #include "memory/allocation.hpp"
+ #include "utilities/chunkedList.hpp"
  
  class Metadata;
  
+ typedef ChunkedList<Metadata*, mtInternal> MetadataOnStackBuffer;
+ 
  // Helper class to mark and unmark metadata used on the stack as either handles
  // or executing methods, so that it can't be deleted during class redefinition
  // and class unloading.
  // This is also used for other things that can be deallocated, like class
  // metadata during parsing, relocated methods, and methods in backtraces.
  class MetadataOnStackMark : public StackObj {
    NOT_PRODUCT(static bool _is_active;)
+ 
+   static volatile MetadataOnStackBuffer* _used_buffers;
+   static volatile MetadataOnStackBuffer* _free_buffers;
+ 
+   static MetadataOnStackBuffer* allocate_buffer();
+   static void retire_buffer(MetadataOnStackBuffer* buffer);
+ 
   public:
!   MetadataOnStackMark(bool visit_code_cache);
     ~MetadataOnStackMark();
! 
!   static void record(Metadata* m, Thread* thread);
!   static void retire_buffer_for_thread(Thread* thread);
!   static bool has_buffer_for_thread(Thread* thread);
  };
  
  #endif // SHARE_VM_CLASSFILE_METADATAONSTACKMARK_HPP