view src/cpu/sparc/vm/bytes_sparc.hpp @ 3249:e1162778c1c8

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer. Reviewed-by: kvn, iveresov, never, tonyp, dholmes
author johnc
date Thu, 07 Apr 2011 09:53:20 -0700
parents f95d63e2154a
children
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.
 *
 */

#ifndef CPU_SPARC_VM_BYTES_SPARC_HPP
#define CPU_SPARC_VM_BYTES_SPARC_HPP

#include "memory/allocation.hpp"

class Bytes: AllStatic {
 public:
  // Efficient reading and writing of unaligned unsigned data in platform-specific byte ordering
  // Sparc needs to check for alignment.

  // can I count on address always being a pointer to an unsigned char? Yes

  // Returns true, if the byte ordering used by Java is different from the nativ byte ordering
  // of the underlying machine. For example, true for Intel x86, False, for Solaris on Sparc.
  static inline bool is_Java_byte_ordering_different() { return false; }

  // Thus, a swap between native and Java ordering is always a no-op:
  static inline u2   swap_u2(u2 x)  { return x; }
  static inline u4   swap_u4(u4 x)  { return x; }
  static inline u8   swap_u8(u8 x)  { return x; }

  static inline u2   get_native_u2(address p){
    return (intptr_t(p) & 1) == 0
             ?   *(u2*)p
             :   ( u2(p[0]) << 8 )
               | ( u2(p[1])      );
  }

  static inline u4   get_native_u4(address p) {
    switch (intptr_t(p) & 3) {
     case 0:  return *(u4*)p;

     case 2:  return (  u4( ((u2*)p)[0] ) << 16  )
                   | (  u4( ((u2*)p)[1] )                  );

    default:  return ( u4(p[0]) << 24 )
                   | ( u4(p[1]) << 16 )
                   | ( u4(p[2]) <<  8 )
                   |   u4(p[3]);
    }
  }

  static inline u8   get_native_u8(address p) {
    switch (intptr_t(p) & 7) {
      case 0:  return *(u8*)p;

      case 4:  return (  u8( ((u4*)p)[0] ) << 32  )
                    | (  u8( ((u4*)p)[1] )        );

      case 2:  return (  u8( ((u2*)p)[0] ) << 48  )
                    | (  u8( ((u2*)p)[1] ) << 32  )
                    | (  u8( ((u2*)p)[2] ) << 16  )
                    | (  u8( ((u2*)p)[3] )        );

     default:  return ( u8(p[0]) << 56 )
                    | ( u8(p[1]) << 48 )
                    | ( u8(p[2]) << 40 )
                    | ( u8(p[3]) << 32 )
                    | ( u8(p[4]) << 24 )
                    | ( u8(p[5]) << 16 )
                    | ( u8(p[6]) <<  8 )
                    |   u8(p[7]);
    }
  }



  static inline void put_native_u2(address p, u2 x)   {
    if ( (intptr_t(p) & 1) == 0 )  *(u2*)p = x;
    else {
      p[0] = x >> 8;
      p[1] = x;
    }
  }

  static inline void put_native_u4(address p, u4 x) {
    switch ( intptr_t(p) & 3 ) {
    case 0:  *(u4*)p = x;
              break;

    case 2:  ((u2*)p)[0] = x >> 16;
             ((u2*)p)[1] = x;
             break;

    default: ((u1*)p)[0] = x >> 24;
             ((u1*)p)[1] = x >> 16;
             ((u1*)p)[2] = x >>  8;
             ((u1*)p)[3] = x;
             break;
    }
  }

  static inline void put_native_u8(address p, u8 x) {
    switch ( intptr_t(p) & 7 ) {
    case 0:  *(u8*)p = x;
             break;

    case 4:  ((u4*)p)[0] = x >> 32;
             ((u4*)p)[1] = x;
             break;

    case 2:  ((u2*)p)[0] = x >> 48;
             ((u2*)p)[1] = x >> 32;
             ((u2*)p)[2] = x >> 16;
             ((u2*)p)[3] = x;
             break;

    default: ((u1*)p)[0] = x >> 56;
             ((u1*)p)[1] = x >> 48;
             ((u1*)p)[2] = x >> 40;
             ((u1*)p)[3] = x >> 32;
             ((u1*)p)[4] = x >> 24;
             ((u1*)p)[5] = x >> 16;
             ((u1*)p)[6] = x >>  8;
             ((u1*)p)[7] = x;
    }
  }


  // Efficient reading and writing of unaligned unsigned data in Java byte ordering (i.e. big-endian ordering)
  // (no byte-order reversal is needed since SPARC CPUs are big-endian oriented)
  static inline u2   get_Java_u2(address p) { return get_native_u2(p); }
  static inline u4   get_Java_u4(address p) { return get_native_u4(p); }
  static inline u8   get_Java_u8(address p) { return get_native_u8(p); }

  static inline void put_Java_u2(address p, u2 x)     { put_native_u2(p, x); }
  static inline void put_Java_u4(address p, u4 x)     { put_native_u4(p, x); }
  static inline void put_Java_u8(address p, u8 x)     { put_native_u8(p, x); }
};

//Reconciliation History
// 1.7 98/02/24 10:18:41 bytes_i486.hpp
// 1.10 98/04/08 18:47:57 bytes_i486.hpp
// 1.13 98/07/15 17:10:03 bytes_i486.hpp
// 1.14 98/08/13 10:38:23 bytes_i486.hpp
// 1.15 98/10/05 16:30:21 bytes_i486.hpp
// 1.17 99/06/22 16:37:35 bytes_i486.hpp
//End

#endif // CPU_SPARC_VM_BYTES_SPARC_HPP