1 /*

     2  * Copyright (c) 2003, 2016, 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  */

    24 

    25 #ifndef SHARE_VM_UTILITIES_COPY_HPP

    26 #define SHARE_VM_UTILITIES_COPY_HPP

    27 

    28 #include "runtime/stubRoutines.hpp"

    29 #include "utilities/align.hpp"

    30 #include "utilities/macros.hpp"

    31 

    32 // Assembly code for platforms that need it.

    33 extern "C" {

    34   void _Copy_conjoint_words(HeapWord* from, HeapWord* to, size_t count);

    35   void _Copy_disjoint_words(HeapWord* from, HeapWord* to, size_t count);

    36 

    37   void _Copy_conjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);

    38   void _Copy_disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);

    39 

    40   void _Copy_aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count);

    41   void _Copy_aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count);

    42 

    43   void _Copy_conjoint_bytes(void* from, void* to, size_t count);

    44 

    45   void _Copy_conjoint_bytes_atomic  (void*   from, void*   to, size_t count);

    46   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count);

    47   void _Copy_conjoint_jints_atomic  (jint*   from, jint*   to, size_t count);

    48   void _Copy_conjoint_jlongs_atomic (jlong*  from, jlong*  to, size_t count);

    49   void _Copy_conjoint_oops_atomic   (oop*    from, oop*    to, size_t count);

    50 

    51   void _Copy_arrayof_conjoint_bytes  (HeapWord* from, HeapWord* to, size_t count);

    52   void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count);

    53   void _Copy_arrayof_conjoint_jints  (HeapWord* from, HeapWord* to, size_t count);

    54   void _Copy_arrayof_conjoint_jlongs (HeapWord* from, HeapWord* to, size_t count);

    55   void _Copy_arrayof_conjoint_oops   (HeapWord* from, HeapWord* to, size_t count);

    56 }

    57 

    58 class Copy : AllStatic {

    59  public:

    60   // Block copy methods have four attributes.  We don't define all possibilities.

    61   //   alignment: aligned to BytesPerLong

    62   //   arrayof:   arraycopy operation with both operands aligned on the same

    63   //              boundary as the first element of an array of the copy unit.

    64   //              This is currently a HeapWord boundary on all platforms, except

    65   //              for long and double arrays, which are aligned on an 8-byte

    66   //              boundary on all platforms.

    67   //              arraycopy operations are implicitly atomic on each array element.

    68   //   overlap:   disjoint or conjoint.

    69   //   copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).

    70   //   atomicity: atomic or non-atomic on the copy unit.

    71   //

    72   // Names are constructed thusly:

    73   //

    74   //     [ 'aligned_' | 'arrayof_' ]

    75   //     ('conjoint_' | 'disjoint_')

    76   //     ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')

    77   //     [ '_atomic' ]

    78   //

    79   // Except in the arrayof case, whatever the alignment is, we assume we can copy

    80   // whole alignment units.  E.g., if BytesPerLong is 2x word alignment, an odd

    81   // count may copy an extra word.  In the arrayof case, we are allowed to copy

    82   // only the number of copy units specified.

    83   //

    84   // All callees check count for 0.

    85   //

    86 

    87   // HeapWords

    88 

    89   // Word-aligned words,    conjoint, not atomic on each word

    90   static void conjoint_words(HeapWord* from, HeapWord* to, size_t count) {

    91     assert_params_ok(from, to, LogHeapWordSize);

    92     pd_conjoint_words(from, to, count);

    93   }

    94 

    95   // Word-aligned words,    disjoint, not atomic on each word

    96   static void disjoint_words(HeapWord* from, HeapWord* to, size_t count) {

    97     assert_params_ok(from, to, LogHeapWordSize);

    98     assert_disjoint(from, to, count);

    99     pd_disjoint_words(from, to, count);

   100   }

   101 

   102   // Word-aligned words,    disjoint, atomic on each word

   103   static void disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count) {

   104     assert_params_ok(from, to, LogHeapWordSize);

   105     assert_disjoint(from, to, count);

   106     pd_disjoint_words_atomic(from, to, count);

   107   }

   108 

   109   // Object-aligned words,  conjoint, not atomic on each word

   110   static void aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {

   111     assert_params_aligned(from, to);

   112     pd_aligned_conjoint_words(from, to, count);

   113   }

   114 

   115   // Object-aligned words,  disjoint, not atomic on each word

   116   static void aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {

   117     assert_params_aligned(from, to);

   118     assert_disjoint(from, to, count);

   119     pd_aligned_disjoint_words(from, to, count);

   120   }

   121 

   122   // bytes, jshorts, jints, jlongs, oops

   123 

   124   // bytes,                 conjoint, not atomic on each byte (not that it matters)

   125   static void conjoint_jbytes(void* from, void* to, size_t count) {

   126     pd_conjoint_bytes(from, to, count);

   127   }

   128 

   129   // bytes,                 conjoint, atomic on each byte (not that it matters)

   130   static void conjoint_jbytes_atomic(void* from, void* to, size_t count) {

   131     pd_conjoint_bytes(from, to, count);

   132   }

   133 

   134   // jshorts,               conjoint, atomic on each jshort

   135   static void conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {

   136     assert_params_ok(from, to, LogBytesPerShort);

   137     pd_conjoint_jshorts_atomic(from, to, count);

   138   }

   139 

   140   // jints,                 conjoint, atomic on each jint

   141   static void conjoint_jints_atomic(jint* from, jint* to, size_t count) {

   142     assert_params_ok(from, to, LogBytesPerInt);

   143     pd_conjoint_jints_atomic(from, to, count);

   144   }

   145 

   146   // jlongs,                conjoint, atomic on each jlong

   147   static void conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {

   148     assert_params_ok(from, to, LogBytesPerLong);

   149     pd_conjoint_jlongs_atomic(from, to, count);

   150   }

   151 

   152   // oops,                  conjoint, atomic on each oop

   153   static void conjoint_oops_atomic(oop* from, oop* to, size_t count) {

   154     assert_params_ok(from, to, LogBytesPerHeapOop);

   155     pd_conjoint_oops_atomic(from, to, count);

   156   }

   157 

   158   // overloaded for UseCompressedOops

   159   static void conjoint_oops_atomic(narrowOop* from, narrowOop* to, size_t count) {

   160     assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");

   161     assert_params_ok(from, to, LogBytesPerInt);

   162     pd_conjoint_jints_atomic((jint*)from, (jint*)to, count);

   163   }

   164 

   165   // Copy a span of memory.  If the span is an integral number of aligned

   166   // longs, words, or ints, copy those units atomically.

   167   // The largest atomic transfer unit is 8 bytes, or the largest power

   168   // of two which divides all of from, to, and size, whichever is smaller.

   169   static void conjoint_memory_atomic(void* from, void* to, size_t size);

   170 

   171   // bytes,                 conjoint array, atomic on each byte (not that it matters)

   172   static void arrayof_conjoint_jbytes(HeapWord* from, HeapWord* to, size_t count) {

   173     pd_arrayof_conjoint_bytes(from, to, count);

   174   }

   175 

   176   // jshorts,               conjoint array, atomic on each jshort

   177   static void arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) {

   178     assert_params_ok(from, to, LogBytesPerShort);

   179     pd_arrayof_conjoint_jshorts(from, to, count);

   180   }

   181 

   182   // jints,                 conjoint array, atomic on each jint

   183   static void arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) {

   184     assert_params_ok(from, to, LogBytesPerInt);

   185     pd_arrayof_conjoint_jints(from, to, count);

   186   }

   187 

   188   // jlongs,                conjoint array, atomic on each jlong

   189   static void arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) {

   190     assert_params_ok(from, to, LogBytesPerLong);

   191     pd_arrayof_conjoint_jlongs(from, to, count);

   192   }

   193 

   194   // oops,                  conjoint array, atomic on each oop

   195   static void arrayof_conjoint_oops(HeapWord* from, HeapWord* to, size_t count) {

   196     assert_params_ok(from, to, LogBytesPerHeapOop);

   197     pd_arrayof_conjoint_oops(from, to, count);

   198   }

   199 

   200   // Known overlap methods

   201 

   202   // Copy word-aligned words from higher to lower addresses, not atomic on each word

   203   inline static void conjoint_words_to_lower(HeapWord* from, HeapWord* to, size_t byte_count) {

   204     // byte_count is in bytes to check its alignment

   205     assert_params_ok(from, to, LogHeapWordSize);

   206     assert_byte_count_ok(byte_count, HeapWordSize);

   207 

   208     size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;

   209     assert(to <= from || from + count <= to, "do not overwrite source data");

   210 

   211     while (count-- > 0) {

   212       *to++ = *from++;

   213     }

   214   }

   215 

   216   // Copy word-aligned words from lower to higher addresses, not atomic on each word

   217   inline static void conjoint_words_to_higher(HeapWord* from, HeapWord* to, size_t byte_count) {

   218     // byte_count is in bytes to check its alignment

   219     assert_params_ok(from, to, LogHeapWordSize);

   220     assert_byte_count_ok(byte_count, HeapWordSize);

   221 

   222     size_t count = align_up(byte_count, HeapWordSize) >> LogHeapWordSize;

   223     assert(from <= to || to + count <= from, "do not overwrite source data");

   224 

   225     from += count - 1;

   226     to   += count - 1;

   227     while (count-- > 0) {

   228       *to-- = *from--;

   229     }

   230   }

   231 

   232   /**

   233    * Copy elements

   234    *

   235    * @param src address of source

   236    * @param dst address of destination

   237    * @param byte_count number of bytes to copy

   238    * @param elem_size size of the elements to copy-swap

   239    */

   240   static void conjoint_copy(const void* src, void* dst, size_t byte_count, size_t elem_size);

   241 

   242   /**

   243    * Copy and *unconditionally* byte swap elements

   244    *

   245    * @param src address of source

   246    * @param dst address of destination

   247    * @param byte_count number of bytes to copy

   248    * @param elem_size size of the elements to copy-swap

   249    */

   250   static void conjoint_swap(const void* src, void* dst, size_t byte_count, size_t elem_size);

   251 

   252   /**

   253    * Copy and byte swap elements from the specified endian to the native (cpu) endian if needed (if they differ)

   254    *

   255    * @param src address of source

   256    * @param dst address of destination

   257    * @param byte_count number of bytes to copy

   258    * @param elem_size size of the elements to copy-swap

   259    */

   260   template <Endian::Order endian>

   261   static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) {

   262     if (Endian::NATIVE != endian) {

   263       conjoint_swap(src, dst, byte_count, elem_size);

   264     } else {

   265       conjoint_copy(src, dst, byte_count, elem_size);

   266     }

   267   }

   268 

   269   // Fill methods

   270 

   271   // Fill word-aligned words, not atomic on each word

   272   // set_words

   273   static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {

   274     assert_params_ok(to, LogHeapWordSize);

   275     pd_fill_to_words(to, count, value);

   276   }

   277 

   278   static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {

   279     assert_params_aligned(to);

   280     pd_fill_to_aligned_words(to, count, value);

   281   }

   282 

   283   // Fill bytes

   284   static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {

   285     pd_fill_to_bytes(to, count, value);

   286   }

   287 

   288   // Fill a span of memory.  If the span is an integral number of aligned

   289   // longs, words, or ints, store to those units atomically.

   290   // The largest atomic transfer unit is 8 bytes, or the largest power

   291   // of two which divides both to and size, whichever is smaller.

   292   static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);

   293 

   294   // Zero-fill methods

   295 

   296   // Zero word-aligned words, not atomic on each word

   297   static void zero_to_words(HeapWord* to, size_t count) {

   298     assert_params_ok(to, LogHeapWordSize);

   299     pd_zero_to_words(to, count);

   300   }

   301 

   302   // Zero bytes

   303   static void zero_to_bytes(void* to, size_t count) {

   304     pd_zero_to_bytes(to, count);

   305   }

   306 

   307  private:

   308   static bool params_disjoint(HeapWord* from, HeapWord* to, size_t count) {

   309     if (from < to) {

   310       return pointer_delta(to, from) >= count;

   311     }

   312     return pointer_delta(from, to) >= count;

   313   }

   314 

   315   // These methods raise a fatal if they detect a problem.

   316 

   317   static void assert_disjoint(HeapWord* from, HeapWord* to, size_t count) {

   318 #ifdef ASSERT

   319     if (!params_disjoint(from, to, count))

   320       basic_fatal("source and dest overlap");

   321 #endif

   322   }

   323 

   324   static void assert_params_ok(void* from, void* to, intptr_t log_align) {

   325 #ifdef ASSERT

   326     if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)

   327       basic_fatal("not aligned");

   328     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)

   329       basic_fatal("not aligned");

   330 #endif

   331   }

   332 

   333   static void assert_params_ok(HeapWord* to, intptr_t log_align) {

   334 #ifdef ASSERT

   335     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)

   336       basic_fatal("not word aligned");

   337 #endif

   338   }

   339   static void assert_params_aligned(HeapWord* from, HeapWord* to) {

   340 #ifdef ASSERT

   341     if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)

   342       basic_fatal("not long aligned");

   343     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)

   344       basic_fatal("not long aligned");

   345 #endif

   346   }

   347 

   348   static void assert_params_aligned(HeapWord* to) {

   349 #ifdef ASSERT

   350     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)

   351       basic_fatal("not long aligned");

   352 #endif

   353   }

   354 

   355   static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {

   356 #ifdef ASSERT

   357     if (!is_aligned(byte_count, unit_size)) {

   358       basic_fatal("byte count must be aligned");

   359     }

   360 #endif

   361   }

   362 

   363   // Platform dependent implementations of the above methods.

   364 #include CPU_HEADER(copy)

   365 

   366 };

   367 

   368 #endif // SHARE_VM_UTILITIES_COPY_HPP