hotspot/src/share/vm/gc/shared/barrierSet.inline.hpp
author stefank
Tue, 04 Jul 2017 15:58:10 +0200
changeset 46619 a3919f5e8d2b
parent 46618 d503911aa948
child 46625 edefffab74e2
permissions -rw-r--r--
8178499: Remove _ptr_ and _size_ infixes from align functions Reviewed-by: rehn, tschatzl

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * accompanied this code).
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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/cardTableModRefBS.inline.hpp"

// Inline functions of BarrierSet, which de-virtualize certain
// performance-critical calls when the barrier is the most common
// card-table kind.

inline bool BarrierSet::devirtualize_reference_writes() const {
  switch (kind()) {
  case CardTableForRS:
  case CardTableExtension:
    return true;
  default:
    return false;
  }
}

template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) {
  if (devirtualize_reference_writes()) {
    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field_pre(field, new_val);
  } else {
    write_ref_field_pre_work(field, new_val);
  }
}

void BarrierSet::write_ref_field(void* field, oop new_val, bool release) {
  if (devirtualize_reference_writes()) {
    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field(field, new_val, release);
  } else {
    write_ref_field_work(field, new_val, release);
  }
}

// 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));
}


inline void BarrierSet::write_region(MemRegion mr) {
  if (devirtualize_reference_writes()) {
    barrier_set_cast<CardTableModRefBS>(this)->inline_write_region(mr);
  } else {
    write_region_work(mr);
  }
}

#endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP