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

@@ -24,22 +24,35 @@
 
 #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();
+  MetadataOnStackMark(bool visit_code_cache);
   ~MetadataOnStackMark();
-  static void record(Metadata* m);
+
+  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