jdk8-mips64-public/hotspot: src/share/vm/utilities/copy.hpp@dee6a1ce4a0c (annotated)

src/share/vm/utilities/copy.hpp@dee6a1ce4a0c (annotated)

src/share/vm/utilities/copy.hpp

Mon, 03 Dec 2018 07:29:54 -0500

author: dbuck
date: Mon, 03 Dec 2018 07:29:54 -0500
changeset 9562: dee6a1ce4a0c
parent 2708: 1d1603768966
child 9572: 624a0741915c
permissions: -rw-r--r--

8141491: Unaligned memory access in Bits.c
Summary: Introduce alignment-safe Copy::conjoint_swap and JVM_CopySwapMemory
Reviewed-by: mikael, dholmes

 /*
  * Copyright (c) 2003, 2018, 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 SHARE_VM_UTILITIES_COPY_HPP
 #define SHARE_VM_UTILITIES_COPY_HPP
 #include "runtime/stubRoutines.hpp"
 // Assembly code for platforms that need it.
 extern "C" {
   void _Copy_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_conjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_conjoint_bytes(void* from, void* to, size_t count);
   void _Copy_conjoint_bytes_atomic  (void*   from, void*   to, size_t count);
   void _Copy_conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count);
   void _Copy_conjoint_jints_atomic  (jint*   from, jint*   to, size_t count);
   void _Copy_conjoint_jlongs_atomic (jlong*  from, jlong*  to, size_t count);
   void _Copy_conjoint_oops_atomic   (oop*    from, oop*    to, size_t count);
   void _Copy_arrayof_conjoint_bytes  (HeapWord* from, HeapWord* to, size_t count);
   void _Copy_arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count);
   void _Copy_arrayof_conjoint_jints  (HeapWord* from, HeapWord* to, size_t count);
   void _Copy_arrayof_conjoint_jlongs (HeapWord* from, HeapWord* to, size_t count);
   void _Copy_arrayof_conjoint_oops   (HeapWord* from, HeapWord* to, size_t count);
 }
 class Copy : AllStatic {
  public:
   // Block copy methods have four attributes.  We don't define all possibilities.
   //   alignment: aligned to BytesPerLong
   //   arrayof:   arraycopy operation with both operands aligned on the same
   //              boundary as the first element of an array of the copy unit.
   //              This is currently a HeapWord boundary on all platforms, except
   //              for long and double arrays, which are aligned on an 8-byte
   //              boundary on all platforms.
   //              arraycopy operations are implicitly atomic on each array element.
   //   overlap:   disjoint or conjoint.
   //   copy unit: bytes or words (i.e., HeapWords) or oops (i.e., pointers).
   //   atomicity: atomic or non-atomic on the copy unit.
   //
   // Names are constructed thusly:
   //
   //     [ 'aligned_' | 'arrayof_' ]
   //     ('conjoint_' | 'disjoint_')
   //     ('words' | 'bytes' | 'jshorts' | 'jints' | 'jlongs' | 'oops')
   //     [ '_atomic' ]
   //
   // Except in the arrayof case, whatever the alignment is, we assume we can copy
   // whole alignment units.  E.g., if BytesPerLong is 2x word alignment, an odd
   // count may copy an extra word.  In the arrayof case, we are allowed to copy
   // only the number of copy units specified.
   //
   // All callees check count for 0.
   //
   // HeapWords
   // Word-aligned words,    conjoint, not atomic on each word
   static void conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogHeapWordSize);
     pd_conjoint_words(from, to, count);
   }
   // Word-aligned words,    disjoint, not atomic on each word
   static void disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogHeapWordSize);
     assert_disjoint(from, to, count);
     pd_disjoint_words(from, to, count);
   }
   // Word-aligned words,    disjoint, atomic on each word
   static void disjoint_words_atomic(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogHeapWordSize);
     assert_disjoint(from, to, count);
     pd_disjoint_words_atomic(from, to, count);
   }
   // Object-aligned words,  conjoint, not atomic on each word
   static void aligned_conjoint_words(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_aligned(from, to);
     pd_aligned_conjoint_words(from, to, count);
   }
   // Object-aligned words,  disjoint, not atomic on each word
   static void aligned_disjoint_words(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_aligned(from, to);
     assert_disjoint(from, to, count);
     pd_aligned_disjoint_words(from, to, count);
   }
   // bytes, jshorts, jints, jlongs, oops
   // bytes,                 conjoint, not atomic on each byte (not that it matters)
   static void conjoint_jbytes(void* from, void* to, size_t count) {
     pd_conjoint_bytes(from, to, count);
   }
   // bytes,                 conjoint, atomic on each byte (not that it matters)
   static void conjoint_jbytes_atomic(void* from, void* to, size_t count) {
     pd_conjoint_bytes(from, to, count);
   }
   // jshorts,               conjoint, atomic on each jshort
   static void conjoint_jshorts_atomic(jshort* from, jshort* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerShort);
     pd_conjoint_jshorts_atomic(from, to, count);
   }
   // jints,                 conjoint, atomic on each jint
   static void conjoint_jints_atomic(jint* from, jint* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerInt);
     pd_conjoint_jints_atomic(from, to, count);
   }
   // jlongs,                conjoint, atomic on each jlong
   static void conjoint_jlongs_atomic(jlong* from, jlong* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerLong);
     pd_conjoint_jlongs_atomic(from, to, count);
   }
   // oops,                  conjoint, atomic on each oop
   static void conjoint_oops_atomic(oop* from, oop* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerHeapOop);
     pd_conjoint_oops_atomic(from, to, count);
   }
   // overloaded for UseCompressedOops
   static void conjoint_oops_atomic(narrowOop* from, narrowOop* to, size_t count) {
     assert(sizeof(narrowOop) == sizeof(jint), "this cast is wrong");
     assert_params_ok(from, to, LogBytesPerInt);
     pd_conjoint_jints_atomic((jint*)from, (jint*)to, count);
   }
   // Copy a span of memory.  If the span is an integral number of aligned
   // longs, words, or ints, copy those units atomically.
   // The largest atomic transfer unit is 8 bytes, or the largest power
   // of two which divides all of from, to, and size, whichever is smaller.
   static void conjoint_memory_atomic(void* from, void* to, size_t size);
   // bytes,                 conjoint array, atomic on each byte (not that it matters)
   static void arrayof_conjoint_jbytes(HeapWord* from, HeapWord* to, size_t count) {
     pd_arrayof_conjoint_bytes(from, to, count);
   }
   // jshorts,               conjoint array, atomic on each jshort
   static void arrayof_conjoint_jshorts(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerShort);
     pd_arrayof_conjoint_jshorts(from, to, count);
   }
   // jints,                 conjoint array, atomic on each jint
   static void arrayof_conjoint_jints(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerInt);
     pd_arrayof_conjoint_jints(from, to, count);
   }
   // jlongs,                conjoint array, atomic on each jlong
   static void arrayof_conjoint_jlongs(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerLong);
     pd_arrayof_conjoint_jlongs(from, to, count);
   }
   // oops,                  conjoint array, atomic on each oop
   static void arrayof_conjoint_oops(HeapWord* from, HeapWord* to, size_t count) {
     assert_params_ok(from, to, LogBytesPerHeapOop);
     pd_arrayof_conjoint_oops(from, to, count);
   }
   // Known overlap methods
   // Copy word-aligned words from higher to lower addresses, not atomic on each word
   inline static void conjoint_words_to_lower(HeapWord* from, HeapWord* to, size_t byte_count) {
     // byte_count is in bytes to check its alignment
     assert_params_ok(from, to, LogHeapWordSize);
     assert_byte_count_ok(byte_count, HeapWordSize);
     size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
     assert(to <= from || from + count <= to, "do not overwrite source data");
     while (count-- > 0) {
       *to++ = *from++;
     }
   }
   // Copy word-aligned words from lower to higher addresses, not atomic on each word
   inline static void conjoint_words_to_higher(HeapWord* from, HeapWord* to, size_t byte_count) {
     // byte_count is in bytes to check its alignment
     assert_params_ok(from, to, LogHeapWordSize);
     assert_byte_count_ok(byte_count, HeapWordSize);
     size_t count = (size_t)round_to(byte_count, HeapWordSize) >> LogHeapWordSize;
     assert(from <= to || to + count <= from, "do not overwrite source data");
     from += count - 1;
     to   += count - 1;
     while (count-- > 0) {
       *to-- = *from--;
     }
   }
   /**
    * Copy and *unconditionally* byte swap elements
    *
    * @param src address of source
    * @param dst address of destination
    * @param byte_count number of bytes to copy
    * @param elem_size size of the elements to copy-swap
    */
   static void conjoint_swap(address src, address dst, size_t byte_count, size_t elem_size);
   // Fill methods
   // Fill word-aligned words, not atomic on each word
   // set_words
   static void fill_to_words(HeapWord* to, size_t count, juint value = 0) {
     assert_params_ok(to, LogHeapWordSize);
     pd_fill_to_words(to, count, value);
   }
   static void fill_to_aligned_words(HeapWord* to, size_t count, juint value = 0) {
     assert_params_aligned(to);
     pd_fill_to_aligned_words(to, count, value);
   }
   // Fill bytes
   static void fill_to_bytes(void* to, size_t count, jubyte value = 0) {
     pd_fill_to_bytes(to, count, value);
   }
   // Fill a span of memory.  If the span is an integral number of aligned
   // longs, words, or ints, store to those units atomically.
   // The largest atomic transfer unit is 8 bytes, or the largest power
   // of two which divides both to and size, whichever is smaller.
   static void fill_to_memory_atomic(void* to, size_t size, jubyte value = 0);
   // Zero-fill methods
   // Zero word-aligned words, not atomic on each word
   static void zero_to_words(HeapWord* to, size_t count) {
     assert_params_ok(to, LogHeapWordSize);
     pd_zero_to_words(to, count);
   }
   // Zero bytes
   static void zero_to_bytes(void* to, size_t count) {
     pd_zero_to_bytes(to, count);
   }
  private:
   static bool params_disjoint(HeapWord* from, HeapWord* to, size_t count) {
     if (from < to) {
       return pointer_delta(to, from) >= count;
     }
     return pointer_delta(from, to) >= count;
   }
   // These methods raise a fatal if they detect a problem.
   static void assert_disjoint(HeapWord* from, HeapWord* to, size_t count) {
 #ifdef ASSERT
     if (!params_disjoint(from, to, count))
       basic_fatal("source and dest overlap");
 #endif
   }
   static void assert_params_ok(void* from, void* to, intptr_t log_align) {
 #ifdef ASSERT
     if (mask_bits((uintptr_t)from, right_n_bits(log_align)) != 0)
       basic_fatal("not aligned");
     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
       basic_fatal("not aligned");
 #endif
   }
   static void assert_params_ok(HeapWord* to, intptr_t log_align) {
 #ifdef ASSERT
     if (mask_bits((uintptr_t)to, right_n_bits(log_align)) != 0)
       basic_fatal("not word aligned");
 #endif
   }
   static void assert_params_aligned(HeapWord* from, HeapWord* to) {
 #ifdef ASSERT
     if (mask_bits((uintptr_t)from, BytesPerLong-1) != 0)
       basic_fatal("not long aligned");
     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
       basic_fatal("not long aligned");
 #endif
   }
   static void assert_params_aligned(HeapWord* to) {
 #ifdef ASSERT
     if (mask_bits((uintptr_t)to, BytesPerLong-1) != 0)
       basic_fatal("not long aligned");
 #endif
   }
   static void assert_byte_count_ok(size_t byte_count, size_t unit_size) {
 #ifdef ASSERT
     if ((size_t)round_to(byte_count, unit_size) != byte_count) {
       basic_fatal("byte count must be aligned");
     }
 #endif
   }
   // Platform dependent implementations of the above methods.
 #ifdef TARGET_ARCH_x86
 # include "copy_x86.hpp"
 #endif
 #ifdef TARGET_ARCH_sparc
 # include "copy_sparc.hpp"
 #endif
 #ifdef TARGET_ARCH_zero
 # include "copy_zero.hpp"
 #endif
 #ifdef TARGET_ARCH_arm
 # include "copy_arm.hpp"
 #endif
 #ifdef TARGET_ARCH_ppc
 # include "copy_ppc.hpp"
 #endif
 };
 #endif // SHARE_VM_UTILITIES_COPY_HPP

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/utilities/copy.hpp@dee6a1ce4a0c (annotated)

src/share/vm/utilities/copy.hpp