src/hotspot/share/runtime/signature.cpp

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

*** 121,139 ****
      tty->print_cr(" @ %d", _index);
    }
  }
  
  
- void SignatureIterator::dispatch_field() {
-   // no '(', just one (field) type
-   _index = 0;
-   _parameter_index = 0;
-   parse_type();
-   check_signature_end();
- }
- 
- 
  void SignatureIterator::iterate_parameters() {
    // Parse parameters
    _index = 0;
    _parameter_index = 0;
    expect('(');
--- 121,130 ----
*** 194,213 ****
          do_double();
          _parameter_index += T_DOUBLE_size;
          break;
        case done_parm:
          return;
-         break;
        default:
          tty->print_cr("*** parameter is " UINT64_FORMAT, fingerprint & parameter_feature_mask);
          tty->print_cr("*** fingerprint is " PTR64_FORMAT, saved_fingerprint);
          ShouldNotReachHere();
          break;
      }
      fingerprint >>= parameter_feature_size;
    }
-   _parameter_index = 0;
  }
  
  
  void SignatureIterator::iterate_returntype() {
    // Ignore parameters
--- 185,202 ----
*** 237,250 ****
            while (sig->char_at(_index++) != ';') ;
          }
          break;
        case '[':
          {
!           int begin = ++_index;
!           while (sig->char_at(_index) == '[') {
!             _index++;
!           }
            if (sig->char_at(_index) == 'L') {
              while (sig->char_at(_index++) != ';') ;
            } else {
              _index++;
            }
--- 226,236 ----
            while (sig->char_at(_index++) != ';') ;
          }
          break;
        case '[':
          {
!           while (sig->char_at(++_index) == '[') ;
            if (sig->char_at(_index) == 'L') {
              while (sig->char_at(_index++) != ';') ;
            } else {
              _index++;
            }
*** 279,299 ****
  }
  
  
  // Implementation of SignatureStream
  SignatureStream::SignatureStream(Symbol* signature, bool is_method) :
!                    _signature(signature), _at_return_type(false) {
    _begin = _end = (is_method ? 1 : 0);  // skip first '(' in method signatures
-   _names = new GrowableArray<Symbol*>(10);
    next();
  }
  
  SignatureStream::~SignatureStream() {
    // decrement refcount for names created during signature parsing
    for (int i = 0; i < _names->length(); i++) {
      _names->at(i)->decrement_refcount();
    }
  }
  
  bool SignatureStream::is_done() const {
    return _end > _signature->utf8_length();
  }
--- 265,286 ----
  }
  
  
  // Implementation of SignatureStream
  SignatureStream::SignatureStream(Symbol* signature, bool is_method) :
!                    _signature(signature), _at_return_type(false), _previous_name(NULL), _names(NULL) {
    _begin = _end = (is_method ? 1 : 0);  // skip first '(' in method signatures
    next();
  }
  
  SignatureStream::~SignatureStream() {
    // decrement refcount for names created during signature parsing
+   if (_names != NULL) {
      for (int i = 0; i < _names->length(); i++) {
        _names->at(i)->decrement_refcount();
      }
+   }
  }
  
  bool SignatureStream::is_done() const {
    return _end > _signature->utf8_length();
  }
*** 357,370 ****
        && _signature->char_at(_end-1) == ';') {
      begin++;
      end--;
    }
  
    // Save names for cleaning up reference count at the end of
    // SignatureStream scope.
!   Symbol* name = SymbolTable::new_symbol(_signature, begin, end, CHECK_NULL);
    _names->push(name);  // save new symbol for decrementing later
    return name;
  }
  
  Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
                                     FailureMode failure_mode, TRAPS) {
--- 344,382 ----
        && _signature->char_at(_end-1) == ';') {
      begin++;
      end--;
    }
  
+   const char* symbol_chars = (const char*)_signature->base() + begin;
+   int len = end - begin;
+ 
+   // Quick check for common symbols in signatures
+   assert((vmSymbols::java_lang_String()->utf8_length() == 16 && vmSymbols::java_lang_Object()->utf8_length() == 16), "sanity");
+   if (len == 16 &&
+       strncmp(symbol_chars, "java/lang/", 10) == 0) {
+     if (strncmp("String", symbol_chars + 10, 6) == 0) {
+       return vmSymbols::java_lang_String();
+     } else if (strncmp("Object", symbol_chars + 10, 6) == 0) {
+       return vmSymbols::java_lang_Object();
+     }
+   }
+ 
+   Symbol* name = _previous_name;
+   if (name != NULL && name->equals(symbol_chars, len)) {
+     return name;
+   }
+ 
    // Save names for cleaning up reference count at the end of
    // SignatureStream scope.
!   name = SymbolTable::new_symbol(symbol_chars, len, CHECK_NULL);
!   if (!name->is_permanent()) {
!     if (_names == NULL) {
!       _names = new GrowableArray<Symbol*>(10);
!     }
      _names->push(name);  // save new symbol for decrementing later
+   }
+   _previous_name = name;
    return name;
  }
  
  Klass* SignatureStream::as_klass(Handle class_loader, Handle protection_domain,
                                     FailureMode failure_mode, TRAPS) {
*** 479,501 ****
        for (index = index + 1; index < limit; ++index) {
          char c = type[index];
          if (c == ';') {
            return index + 1;
          }
!         if (invalid_name_char(c)) {
            return -1;
          }
        }
        // fall through
      default: ; // fall through
    }
    return -1;
  }
- 
- bool SignatureVerifier::invalid_name_char(char c) {
-   switch (c) {
-     case '\0': case '.': case ';': case '[':
-       return true;
-     default:
-       return false;
-   }
- }
--- 491,506 ----
        for (index = index + 1; index < limit; ++index) {
          char c = type[index];
          if (c == ';') {
            return index + 1;
          }
!         switch (c) {
!           case '\0': case '.': case '[':
              return -1;
+           default: ; // fall through
          }
        }
        // fall through
      default: ; // fall through
    }
    return -1;
  }