jdk8-mips64-public/hotspot: src/share/vm/runtime/fieldType.hpp@72053ed6f8d4

8057003: Large reference arrays cause extremely long synchronization times
Summary: Slice large object arrays into parts so that the synchronization of marking threads with an STW pause request does not take long.
Reviewed-by: ehelin, pliden
Contributed-by: maoliang.ml@alibaba-inc.com

     1 /*

     2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    25 #ifndef SHARE_VM_RUNTIME_FIELDTYPE_HPP

    26 #define SHARE_VM_RUNTIME_FIELDTYPE_HPP

    28 #include "memory/allocation.hpp"

    29 #include "oops/symbol.hpp"

    31 // Note: FieldType should be based on the SignatureIterator (or vice versa).

    32 //       In any case, this structure should be re-thought at some point.

    34 // A FieldType is used to determine the type of a field from a signature string.

    36 // Information returned by get_array_info, which is scoped to decrement

    37 // reference count if a Symbol is created in the case of T_OBJECT

    38 class FieldArrayInfo : public StackObj {

    39   friend class FieldType;  // field type can set these fields.

    40   int       _dimension;

    41   Symbol*   _object_key;

    42  public:

    43   int       dimension()    { return _dimension; }

    44   Symbol*   object_key()   { return _object_key; }

    45   // basic constructor

    46   FieldArrayInfo() : _dimension(0), _object_key(NULL) {}

    47   // destructor decrements object key's refcount if created

    48   ~FieldArrayInfo() { if (_object_key != NULL) _object_key->decrement_refcount(); }

    49 };

    52 class FieldType: public AllStatic {

    53  private:

    54   static void skip_optional_size(Symbol* signature, int* index);

    55   static bool is_valid_array_signature(Symbol* signature);

    56  public:

    58   // Return basic type

    59   static BasicType basic_type(Symbol* signature);

    61   // Testing

    62   static bool is_array(Symbol* signature) { return signature->utf8_length() > 1 && signature->byte_at(0) == '[' && is_valid_array_signature(signature); }

    64   static bool is_obj(Symbol* signature) {

    65      int sig_length = signature->utf8_length();

    66      // Must start with 'L' and end with ';'

    67      return (sig_length >= 2 &&

    68              (signature->byte_at(0) == 'L') &&

    69              (signature->byte_at(sig_length - 1) == ';'));

    70   }

    72   // Parse field and extract array information. Works for T_ARRAY only.

    73   static BasicType get_array_info(Symbol* signature, FieldArrayInfo& ai, TRAPS);

    74 };

    76 #endif // SHARE_VM_RUNTIME_FIELDTYPE_HPP

Mercurial > jdk8-mips64-public > hotspot / file revision

src/share/vm/runtime/fieldType.hpp@72053ed6f8d4

src/share/vm/runtime/fieldType.hpp