1 /*
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 3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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 "utilities/align.hpp"
30 
31 // count is number of array elements being written
32 void BarrierSet::write_ref_array(HeapWord* start, size_t count) {
33   assert(count <= (size_t)max_intx, "count too large");
34   HeapWord* end = (HeapWord*)((char*)start + (count*heapOopSize));
35   // In the case of compressed oops, start and end may potentially be misaligned;
36   // so we need to conservatively align the first downward (this is not
37   // strictly necessary for current uses, but a case of good hygiene and,
38   // if you will, aesthetics) and the second upward (this is essential for
39   // current uses) to a HeapWord boundary, so we mark all cards overlapping
40   // this write. If this evolves in the future to calling a
41   // logging barrier of narrow oop granularity, like the pre-barrier for G1
42   // (mentioned here merely by way of example), we will need to change this
43   // interface, so it is "exactly precise" (if i may be allowed the adverbial
44   // redundancy for emphasis) and does not include narrow oop slots not
45   // included in the original write interval.
46   HeapWord* aligned_start = align_down(start, HeapWordSize);
47   HeapWord* aligned_end   = align_up  (end,   HeapWordSize);
48   // If compressed oops were not being used, these should already be aligned
49   assert(UseCompressedOops || (aligned_start == start && aligned_end == end),
50          "Expected heap word alignment of start and end");
51   write_ref_array_work(MemRegion(aligned_start, aligned_end));
52 }
53 
54 #endif // SHARE_VM_GC_SHARED_BARRIERSET_INLINE_HPP