src/hotspot/share/gc/shared/barrierSet.inline.hpp
author stefank
Thu, 22 Feb 2018 18:36:32 +0100
changeset 49048 4e8c86b75428
parent 48961 120b61d50f85
child 49347 edb65305d3ac
permissions -rw-r--r--
8198525: Move _size_policy out of GenCollectorPolicy into GenCollectedHeap Reviewed-by: pliden, sjohanss

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#ifndef SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
#define SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP

#include "gc/shared/barrierSet.hpp"
#include "gc/shared/barrierSetConfig.inline.hpp"
#include "utilities/align.hpp"

// count is number of array elements being written
void BarrierSet::write_ref_array(HeapWord* start, size_t count) {
  assert(count <= (size_t)max_intx, "count too large");
  HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
  // In the case of compressed oops, start and end may potentially be misaligned;
  // so we need to conservatively align the first downward (this is not
  // strictly necessary for current uses, but a case of good hygiene and,
  // if you will, aesthetics) and the second upward (this is essential for
  // current uses) to a HeapWord boundary, so we mark all cards overlapping
  // this write. If this evolves in the future to calling a
  // logging barrier of narrow oop granularity, like the pre-barrier for G1
  // (mentioned here merely by way of example), we will need to change this
  // interface, so it is "exactly precise" (if i may be allowed the adverbial
  // redundancy for emphasis) and does not include narrow oop slots not
  // included in the original write interval.
  HeapWord* aligned_start = align_down(start, HeapWordSize);
  HeapWord* aligned_end   = align_up  (end,   HeapWordSize);
  // If compressed oops were not being used, these should already be aligned
  assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
         "Expected heap word alignment of start and end");
  write_ref_array_work(MemRegion(aligned_start, aligned_end));
}

#endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP