src/hotspot/share/classfile/verifier.hpp

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

@@ -248,10 +248,12 @@
 
 // A new instance of this class is created for each class being verified
 class ClassVerifier : public StackObj {
  private:
   Thread* _thread;
+
+  Symbol* _previous_symbol;          // cache of the previously looked up symbol
   GrowableArray<Symbol*>* _symbols;  // keep a list of symbols created
 
   Symbol* _exception_type;
   char* _message;
 

@@ -409,16 +411,22 @@
   // their reference counts need to be decremented when the verifier object
   // goes out of scope.  Since these symbols escape the scope in which they're
   // created, we can't use a TempNewSymbol.
   Symbol* create_temporary_symbol(const Symbol* s, int begin, int end, TRAPS);
   Symbol* create_temporary_symbol(const char *s, int length, TRAPS);
-
   Symbol* create_temporary_symbol(Symbol* s) {
-    // This version just updates the reference count and saves the symbol to be
-    // dereferenced later.
+    if (s == _previous_symbol) {
+      return s;
+    }
+    if (!s->is_permanent()) {
     s->increment_refcount();
+      if (_symbols == NULL) {
+        _symbols = new GrowableArray<Symbol*>(50, 0, NULL);
+      }
     _symbols->push(s);
+    }
+    _previous_symbol = s;
     return s;
   }
 
   TypeOrigin ref_ctx(const char* str, TRAPS);