view src/share/vm/memory/oopFactory.hpp @ 1716:be3f9c242c9d

6948538: CMS: BOT walkers can fall into object allocation and initialization cracks Summary: GC workers now recognize an intermediate transient state of blocks which are allocated but have not yet completed initialization. blk_start() calls do not attempt to determine the size of a block in the transient state, rather waiting for the block to become initialized so that it is safe to query its size. Audited and ensured the order of initialization of object fields (klass, free bit and size) to respect block state transition protocol. Also included some new assertion checking code enabled in debug mode. Reviewed-by: chrisphi, johnc, poonam
author ysr
date Mon, 16 Aug 2010 15:58:42 -0700
parents c18cbe5936b8
children f95d63e2154a
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/*
 * Copyright (c) 1997, 2009, 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.
 *
 */

// oopFactory is a class used for creating new objects.

class vframeArray;

class oopFactory: AllStatic {
 public:
  // Basic type leaf array allocation
  static typeArrayOop    new_boolArray  (int length, TRAPS) { return typeArrayKlass::cast(Universe::boolArrayKlassObj  ())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_charArray  (int length, TRAPS) { return typeArrayKlass::cast(Universe::charArrayKlassObj  ())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_singleArray(int length, TRAPS) { return typeArrayKlass::cast(Universe::singleArrayKlassObj())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_doubleArray(int length, TRAPS) { return typeArrayKlass::cast(Universe::doubleArrayKlassObj())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_byteArray  (int length, TRAPS) { return typeArrayKlass::cast(Universe::byteArrayKlassObj  ())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_shortArray (int length, TRAPS) { return typeArrayKlass::cast(Universe::shortArrayKlassObj ())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_intArray   (int length, TRAPS) { return typeArrayKlass::cast(Universe::intArrayKlassObj   ())->allocate(length, CHECK_NULL); }
  static typeArrayOop    new_longArray  (int length, TRAPS) { return typeArrayKlass::cast(Universe::longArrayKlassObj  ())->allocate(length, CHECK_NULL); }

  // create java.lang.Object[]
  static objArrayOop     new_objectArray(int length, TRAPS)  {
    return objArrayKlass::
      cast(Universe::objectArrayKlassObj())->allocate(length, CHECK_NULL);
  }

  static typeArrayOop    new_charArray           (const char* utf8_str,  TRAPS);
  static typeArrayOop    new_permanent_charArray (int length, TRAPS);
  static typeArrayOop    new_permanent_byteArray (int length, TRAPS);  // used for class file structures
  static typeArrayOop    new_permanent_shortArray(int length, TRAPS);  // used for class file structures
  static typeArrayOop    new_permanent_intArray  (int length, TRAPS);  // used for class file structures

  static typeArrayOop    new_typeArray(BasicType type, int length, TRAPS);

  // Symbols
  static symbolOop new_symbol(const char* utf8_buffer, int length, TRAPS) {
    assert(utf8_buffer != NULL, "just checking");
    return SymbolTable::lookup(utf8_buffer, length, CHECK_NULL);
  }
  static void new_symbols(constantPoolHandle cp, int names_count,
                          const char** name, int* lengths,
                          int* cp_indices, unsigned int* hashValues,
                          TRAPS) {
    SymbolTable::add(cp, names_count, name, lengths, cp_indices,
                     hashValues, CHECK);
  }

  static symbolOop       new_symbol(char* name, TRAPS) { return new_symbol(name, (int)strlen(name), CHECK_NULL); }
  static symbolOop       new_symbol(const char* name, TRAPS) { return new_symbol(name, (int)strlen(name), CHECK_NULL); }
  static symbolOop       new_symbol(symbolHandle sym, int begin, int end, TRAPS) {
    assert(begin <= end && end <= sym->utf8_length(), "just checking");
    return SymbolTable::lookup(sym, begin, end, CHECK_NULL);
  }

  // Create symbols as above but return a handle
  static symbolHandle    new_symbol_handle(const char* name, int length, TRAPS) {
    symbolOop sym = new_symbol(name, length, THREAD);
    return symbolHandle(THREAD, sym);
  }
  static symbolHandle    new_symbol_handle(char* name, TRAPS) { return new_symbol_handle(name, (int)strlen(name), CHECK_(symbolHandle())); }
  static symbolHandle    new_symbol_handle(const char* name, TRAPS) { return new_symbol_handle(name, (int)strlen(name), CHECK_(symbolHandle())); }

  // Constant pools
  static constantPoolOop      new_constantPool     (int length,
                                                    bool is_conc_safe,
                                                    TRAPS);
  static constantPoolCacheOop new_constantPoolCache(int length,
                                                    bool is_conc_safe,
                                                    TRAPS);

  // Instance classes
  static klassOop        new_instanceKlass(int vtable_len, int itable_len,
                                           int static_field_size,
                                           unsigned int nonstatic_oop_map_count,
                                           ReferenceType rt, TRAPS);

  // Methods
private:
  static constMethodOop  new_constMethod(int byte_code_size,
                                         int compressed_line_number_size,
                                         int localvariable_table_length,
                                         int checked_exceptions_length,
                                         bool is_conc_safe,
                                         TRAPS);
public:
  // Set is_conc_safe for methods which cannot safely be
  // processed by concurrent GC even after the return of
  // the method.
  static methodOop       new_method(int byte_code_size,
                                    AccessFlags access_flags,
                                    int compressed_line_number_size,
                                    int localvariable_table_length,
                                    int checked_exceptions_length,
                                    bool is_conc_safe,
                                    TRAPS);

  // Method Data containers
  static methodDataOop   new_methodData(methodHandle method, TRAPS);

  // System object arrays
  static objArrayOop     new_system_objArray(int length, TRAPS);

  // Regular object arrays
  static objArrayOop     new_objArray(klassOop klass, int length, TRAPS);

  // For compiled ICs
  static compiledICHolderOop new_compiledICHolder(methodHandle method, KlassHandle klass, TRAPS);
};