1 /*

     2  * Copyright 2002-2005 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   volatile int _flags;

    27 

    28 public:

    29 

    30    enum pd_Constants {

    31      flushed = 1                                 // winodows have flushed

    32    };

    33 

    34   int flags(void)                                { return _flags; }

    35   void set_flags(int flags)                      { _flags = flags; }

    36 

    37   static ByteSize flags_offset()                 { return byte_offset_of(JavaFrameAnchor, _flags); }

    38 

    39   // Each arch must define clear, copy

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

    41   //  1 - initializing a new state (thread creation, javaCalls)

    42   //  2 - saving a current state (javaCalls)

    43   //  3 - restoring an old state (javaCalls)

    44 

    45   void clear(void) {

    46     // clearing _last_Java_sp must be first

    47     _last_Java_sp = NULL;

    48     // fence?

    49     _flags = 0;

    50     _last_Java_pc = NULL;

    51   }

    52 

    53   void copy(JavaFrameAnchor* src) {

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

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

    56     //

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

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

    59     // unless the value is changing

    60     //

    61     if (_last_Java_sp != src->_last_Java_sp)

    62       _last_Java_sp = NULL;

    63 

    64     _flags = src->_flags;

    65     _last_Java_pc = src->_last_Java_pc;

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

    67     _last_Java_sp = src->_last_Java_sp;

    68   }

    69 

    70   // Is stack walkable

    71   inline bool walkable( void) {

    72         return _flags & flushed;

    73   }

    74 

    75   void make_walkable(JavaThread* thread);

    76 

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

    78 

    79   // These are only used by friends

    80 private:

    81 

    82   intptr_t* last_Java_sp() const {

    83     // _last_Java_sp will always be a an unbiased stack pointer

    84     // if is is biased then some setter screwed up. This is

    85     // deadly.

    86 #ifdef _LP64

    87     assert(((intptr_t)_last_Java_sp & 0xF) == 0, "Biased last_Java_sp");

    88 #endif

    89     return _last_Java_sp;

    90   }

    91 

    92   void capture_last_Java_pc(intptr_t* sp);

    93 

    94   void set_window_flushed( void) {

    95     _flags |= flushed;

    96     OrderAccess::fence();

    97   }