src/hotspot/share/utilities/copy.hpp
changeset 47216 71c04702a3d5
parent 46625 edefffab74e2
child 48951 950c35ea6237
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/utilities/copy.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 2003, 2016, 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"
+#include "utilities/align.hpp"
+#include "utilities/macros.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 = align_up(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 = align_up(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 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_copy(const void* src, void* dst, size_t byte_count, size_t elem_size);
+
+  /**
+   * 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(const void* src, void* dst, size_t byte_count, size_t elem_size);
+
+  /**
+   * Copy and byte swap elements from the specified endian to the native (cpu) endian if needed (if they differ)
+   *
+   * @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
+   */
+  template <Endian::Order endian>
+  static void conjoint_swap_if_needed(const void* src, void* dst, size_t byte_count, size_t elem_size) {
+    if (Endian::NATIVE != endian) {
+      conjoint_swap(src, dst, byte_count, elem_size);
+    } else {
+      conjoint_copy(src, dst, byte_count, 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 (!is_aligned(byte_count, unit_size)) {
+      basic_fatal("byte count must be aligned");
+    }
+#endif
+  }
+
+  // Platform dependent implementations of the above methods.
+#include CPU_HEADER(copy)
+
+};
+
+#endif // SHARE_VM_UTILITIES_COPY_HPP