src/hotspot/share/gc/shared/collectedHeap.inline.hpp

/*
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 * 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
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 *
 * 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.
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#ifndef SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP
#define SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP

#include "gc/shared/collectedHeap.hpp"
#include "oops/oop.inline.hpp"
#include "utilities/align.hpp"

inline HeapWord* CollectedHeap::align_allocation_or_fail(HeapWord* addr,
                                                         HeapWord* end,
                                                         unsigned short alignment_in_bytes) {
  if (alignment_in_bytes <= ObjectAlignmentInBytes) {
    return addr;
  }

  assert(is_aligned(addr, HeapWordSize),
         "Address " PTR_FORMAT " is not properly aligned.", p2i(addr));
  assert(is_aligned(alignment_in_bytes, HeapWordSize),
         "Alignment size %u is incorrect.", alignment_in_bytes);

  HeapWord* new_addr = align_up(addr, alignment_in_bytes);
  size_t padding = pointer_delta(new_addr, addr);

  if (padding == 0) {
    return addr;
  }

  if (padding < CollectedHeap::min_fill_size()) {
    padding += alignment_in_bytes / HeapWordSize;
    assert(padding >= CollectedHeap::min_fill_size(),
           "alignment_in_bytes %u is expect to be larger "
           "than the minimum object size", alignment_in_bytes);
    new_addr = addr + padding;
  }

  assert(new_addr > addr, "Unexpected arithmetic overflow "
         PTR_FORMAT " not greater than " PTR_FORMAT, p2i(new_addr), p2i(addr));
  if(new_addr < end) {
    CollectedHeap::fill_with_object(addr, padding);
    return new_addr;
  } else {
    return NULL;
  }
}

#endif // SHARE_VM_GC_SHARED_COLLECTEDHEAP_INLINE_HPP