barrierSet.inline.hpp revision 13249:a2753984d2c1 
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24
25#ifndef SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
26#define SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
27
28#include "gc/shared/barrierSet.hpp"
29#include "gc/shared/cardTableModRefBS.inline.hpp"
30#include "utilities/align.hpp"
31
32// Inline functions of BarrierSet, which de-virtualize certain
33// performance-critical calls when the barrier is the most common
34// card-table kind.
35
36inline bool BarrierSet::devirtualize_reference_writes() const {
37  switch (kind()) {
38  case CardTableForRS:
39  case CardTableExtension:
40    return true;
41  default:
42    return false;
43  }
44}
45
46template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) {
47  if (devirtualize_reference_writes()) {
48    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field_pre(field, new_val);
49  } else {
50    write_ref_field_pre_work(field, new_val);
51  }
52}
53
54void BarrierSet::write_ref_field(void* field, oop new_val, bool release) {
55  if (devirtualize_reference_writes()) {
56    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field(field, new_val, release);
57  } else {
58    write_ref_field_work(field, new_val, release);
59  }
60}
61
62// count is number of array elements being written
63void BarrierSet::write_ref_array(HeapWord* start, size_t count) {
64  assert(count <= (size_t)max_intx, "count too large");
65  HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
66  // In the case of compressed oops, start and end may potentially be misaligned;
67  // so we need to conservatively align the first downward (this is not
68  // strictly necessary for current uses, but a case of good hygiene and,
69  // if you will, aesthetics) and the second upward (this is essential for
70  // current uses) to a HeapWord boundary, so we mark all cards overlapping
71  // this write. If this evolves in the future to calling a
72  // logging barrier of narrow oop granularity, like the pre-barrier for G1
73  // (mentioned here merely by way of example), we will need to change this
74  // interface, so it is "exactly precise" (if i may be allowed the adverbial
75  // redundancy for emphasis) and does not include narrow oop slots not
76  // included in the original write interval.
77  HeapWord* aligned_start = align_down(start, HeapWordSize);
78  HeapWord* aligned_end   = align_up  (end,   HeapWordSize);
79  // If compressed oops were not being used, these should already be aligned
80  assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
81         "Expected heap word alignment of start and end");
82  write_ref_array_work(MemRegion(aligned_start, aligned_end));
83}
84
85
86inline void BarrierSet::write_region(MemRegion mr) {
87  if (devirtualize_reference_writes()) {
88    barrier_set_cast<CardTableModRefBS>(this)->inline_write_region(mr);
89  } else {
90    write_region_work(mr);
91  }
92}
93
94#endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
95