barrierSet.inline.hpp revision 13243:7235bc30c0d7 
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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
31// Inline functions of BarrierSet, which de-virtualize certain
32// performance-critical calls when the barrier is the most common
33// card-table kind.
34
35inline bool BarrierSet::devirtualize_reference_writes() const {
36  switch (kind()) {
37  case CardTableForRS:
38  case CardTableExtension:
39    return true;
40  default:
41    return false;
42  }
43}
44
45template <class T> void BarrierSet::write_ref_field_pre(T* field, oop new_val) {
46  if (devirtualize_reference_writes()) {
47    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field_pre(field, new_val);
48  } else {
49    write_ref_field_pre_work(field, new_val);
50  }
51}
52
53void BarrierSet::write_ref_field(void* field, oop new_val, bool release) {
54  if (devirtualize_reference_writes()) {
55    barrier_set_cast<CardTableModRefBS>(this)->inline_write_ref_field(field, new_val, release);
56  } else {
57    write_ref_field_work(field, new_val, release);
58  }
59}
60
61// count is number of array elements being written
62void BarrierSet::write_ref_array(HeapWord* start, size_t count) {
63  assert(count <= (size_t)max_intx, "count too large");
64  HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
65  // In the case of compressed oops, start and end may potentially be misaligned;
66  // so we need to conservatively align the first downward (this is not
67  // strictly necessary for current uses, but a case of good hygiene and,
68  // if you will, aesthetics) and the second upward (this is essential for
69  // current uses) to a HeapWord boundary, so we mark all cards overlapping
70  // this write. If this evolves in the future to calling a
71  // logging barrier of narrow oop granularity, like the pre-barrier for G1
72  // (mentioned here merely by way of example), we will need to change this
73  // interface, so it is "exactly precise" (if i may be allowed the adverbial
74  // redundancy for emphasis) and does not include narrow oop slots not
75  // included in the original write interval.
76  HeapWord* aligned_start = align_down(start, HeapWordSize);
77  HeapWord* aligned_end   = align_up  (end,   HeapWordSize);
78  // If compressed oops were not being used, these should already be aligned
79  assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
80         "Expected heap word alignment of start and end");
81  write_ref_array_work(MemRegion(aligned_start, aligned_end));
82}
83
84
85inline void BarrierSet::write_region(MemRegion mr) {
86  if (devirtualize_reference_writes()) {
87    barrier_set_cast<CardTableModRefBS>(this)->inline_write_region(mr);
88  } else {
89    write_region_work(mr);
90  }
91}
92
93#endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP
94