1 /*

     2  * Copyright 2002-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 private:

    26 

    27   // FP value associated with _last_Java_sp:

    28   intptr_t* volatile        _last_Java_fp;           // pointer is volatile not what it points to

    29 

    30 public:

    31   // Each arch must define reset, save, restore

    32   // These are used by objects that only care about:

    33   //  1 - initializing a new state (thread creation, javaCalls)

    34   //  2 - saving a current state (javaCalls)

    35   //  3 - restoring an old state (javaCalls)

    36 

    37   void clear(void) {

    38     // clearing _last_Java_sp must be first

    39     _last_Java_sp = NULL;

    40     // fence?

    41     _last_Java_fp = NULL;

    42     _last_Java_pc = NULL;

    43   }

    44 

    45   void copy(JavaFrameAnchor* src) {

    46     // In order to make sure the transition state is valid for "this"

    47     // We must clear _last_Java_sp before copying the rest of the new data

    48     //

    49     // Hack Alert: Temporary bugfix for 4717480/4721647

    50     // To act like previous version (pd_cache_state) don't NULL _last_Java_sp

    51     // unless the value is changing

    52     //

    53     if (_last_Java_sp != src->_last_Java_sp)

    54       _last_Java_sp = NULL;

    55 

    56     _last_Java_fp = src->_last_Java_fp;

    57     _last_Java_pc = src->_last_Java_pc;

    58     // Must be last so profiler will always see valid frame if has_last_frame() is true

    59     _last_Java_sp = src->_last_Java_sp;

    60   }

    61 

    62   // Always walkable

    63   bool walkable(void) { return true; }

    64   // Never any thing to do since we are always walkable and can find address of return addresses

    65   void make_walkable(JavaThread* thread) { }

    66 

    67   intptr_t* last_Java_sp(void) const             { return _last_Java_sp; }

    68 

    69 private:

    70 

    71   static ByteSize last_Java_fp_offset()          { return byte_offset_of(JavaFrameAnchor, _last_Java_fp); }

    72 

    73 public:

    74 

    75   void set_last_Java_sp(intptr_t* sp)            { _last_Java_sp = sp; }

    76 

    77   intptr_t*   last_Java_fp(void)                     { return _last_Java_fp; }

    78   // Assert (last_Java_sp == NULL || fp == NULL)

    79   void set_last_Java_fp(intptr_t* fp)                { _last_Java_fp = fp; }