view src/share/vm/runtime/fieldType.cpp @ 2149:7e37af9d69ef

7011379: G1: overly long concurrent marking cycles Summary: This changeset introduces filtering of SATB buffers at the point when they are about to be enqueued. If this filtering clears enough entries on each buffer, the buffer can then be re-used and not enqueued. This cuts down the number of SATB buffers that need to be processed by the concurrent marking threads. Reviewed-by: johnc, ysr
author tonyp
date Wed, 19 Jan 2011 09:35:17 -0500
parents f95d63e2154a
children 3582bf76420e
line wrap: on
line source

/*
 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 *
 */

#include "precompiled.hpp"
#include "classfile/systemDictionary.hpp"
#include "memory/oopFactory.hpp"
#include "oops/oop.inline.hpp"
#include "oops/typeArrayKlass.hpp"
#include "runtime/fieldType.hpp"
#include "runtime/signature.hpp"

void FieldType::skip_optional_size(symbolOop signature, int* index) {
  jchar c = signature->byte_at(*index);
  while (c >= '0' && c <= '9') {
    *index = *index + 1;
    c = signature->byte_at(*index);
  }
}

BasicType FieldType::basic_type(symbolOop signature) {
  return char2type(signature->byte_at(0));
}

// Check if it is a valid array signature
bool FieldType::is_valid_array_signature(symbolOop sig) {
  assert(sig->utf8_length() > 1, "this should already have been checked");
  assert(sig->byte_at(0) == '[', "this should already have been checked");
  // The first character is already checked
  int i = 1;
  int len = sig->utf8_length();
  // First skip all '['s
  while(i < len - 1 && sig->byte_at(i) == '[') i++;

  // Check type
  switch(sig->byte_at(i)) {
    case 'B': // T_BYTE
    case 'C': // T_CHAR
    case 'D': // T_DOUBLE
    case 'F': // T_FLOAT
    case 'I': // T_INT
    case 'J': // T_LONG
    case 'S': // T_SHORT
    case 'Z': // T_BOOLEAN
      // If it is an array, the type is the last character
      return (i + 1 == len);
    case 'L':
      // If it is an object, the last character must be a ';'
      return sig->byte_at(len - 1) == ';';
  }

  return false;
}


BasicType FieldType::get_array_info(symbolOop signature, jint* dimension, symbolOop* object_key, TRAPS) {
  assert(basic_type(signature) == T_ARRAY, "must be array");
  int index = 1;
  int dim   = 1;
  skip_optional_size(signature, &index);
  while (signature->byte_at(index) == '[') {
    index++;
    dim++;
    skip_optional_size(signature, &index);
  }
  ResourceMark rm;
  symbolOop element = oopFactory::new_symbol(signature->as_C_string() + index, CHECK_(T_BYTE));
  BasicType element_type = FieldType::basic_type(element);
  if (element_type == T_OBJECT) {
    char* object_type = element->as_C_string();
    object_type[element->utf8_length() - 1] = '\0';
    *object_key = oopFactory::new_symbol(object_type + 1, CHECK_(T_BYTE));
  }
  // Pass dimension back to caller
  *dimension = dim;
  return element_type;
}