Mon, 02 Aug 2010 12:51:43 -0700
6814437: G1: remove the _new_refs array
Summary: The per-worker _new_refs array is used to hold references that point into the collection set. It is populated during RSet updating and subsequently processed. In the event of an evacuation failure it processed again to recreate the RSets of regions in the collection set. Remove the per-worker _new_refs array by processing the references directly. Use a DirtyCardQueue to hold the cards containing the references so that the RSets of regions in the collection set can be recreated when handling an evacuation failure.
Reviewed-by: iveresov, jmasa, tonyp
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25 inline HeapWord* G1OffsetTableContigSpace::allocate(size_t size) {
26 HeapWord* res = ContiguousSpace::allocate(size);
27 if (res != NULL) {
28 _offsets.alloc_block(res, size);
29 }
30 return res;
31 }
33 // Because of the requirement of keeping "_offsets" up to date with the
34 // allocations, we sequentialize these with a lock. Therefore, best if
35 // this is used for larger LAB allocations only.
36 inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t size) {
37 MutexLocker x(&_par_alloc_lock);
38 // This ought to be just "allocate", because of the lock above, but that
39 // ContiguousSpace::allocate asserts that either the allocating thread
40 // holds the heap lock or it is the VM thread and we're at a safepoint.
41 // The best I (dld) could figure was to put a field in ContiguousSpace
42 // meaning "locking at safepoint taken care of", and set/reset that
43 // here. But this will do for now, especially in light of the comment
44 // above. Perhaps in the future some lock-free manner of keeping the
45 // coordination.
46 HeapWord* res = ContiguousSpace::par_allocate(size);
47 if (res != NULL) {
48 _offsets.alloc_block(res, size);
49 }
50 return res;
51 }
53 inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
54 return _offsets.block_start(p);
55 }
57 inline HeapWord*
58 G1OffsetTableContigSpace::block_start_const(const void* p) const {
59 return _offsets.block_start_const(p);
60 }