src/hotspot/share/oops/symbol.cpp

rev 54022 : 8220366: Optimize Symbol handling in ClassVerifier and SignatureStream
Reviewed-by: TBD

*** 262,271 ****
--- 262,295 ----
        // refcount changed, try again.
      }
    }
  }
  
+ void Symbol::make_permanent() {
+   uint32_t found = _length_and_refcount;
+   while (true) {
+     uint32_t old_value = found;
+     int refc = extract_refcount(old_value);
+     int len = extract_length(old_value);
+     if (refc == PERM_REFCOUNT) {
+       return;  // refcount is permanent, permanent is sticky
+     } else if (refc == 0) {
+ #ifdef ASSERT
+       print();
+       fatal("refcount underflow");
+ #endif
+       return;
+     } else {
+       found = Atomic::cmpxchg(pack_length_and_refcount(len, PERM_REFCOUNT), &_length_and_refcount, old_value);
+       if (found == old_value) {
+         return;  // successfully updated.
+       }
+       // refcount changed, try again.
+     }
+   }
+ }
+ 
  void Symbol::metaspace_pointers_do(MetaspaceClosure* it) {
    if (log_is_enabled(Trace, cds)) {
      LogStream trace_stream(Log(cds)::trace());
      trace_stream.print("Iter(Symbol): %p ", this);
      print_value_on(&trace_stream);