Mercurial > hg > truffle
diff src/share/vm/gc_implementation/g1/concurrentMark.cpp @ 1359:23b1b27ac76c
6909756: G1: guarantee(G1CollectedHeap::heap()->mark_in_progress(),"Precondition.")
Summary: Make sure that two marking cycles do not overlap, i.e., a new one can only start after the concurrent marking thread finishes all its work. In the fix I piggy-back a couple of minor extra fixes: some general code reformatting for consistency (only around the code I modified), the removal of a field (G1CollectorPolicy::_should_initiate_conc_mark) which doesn't seem to be used at all (it's only set but never read), as well as moving the "is GC locker active" test earlier into the G1 pause / Full GC and using a more appropriate method for it.
Reviewed-by: johnc, jmasa, jcoomes, ysr
author | tonyp |
---|---|
date | Tue, 06 Apr 2010 10:59:45 -0400 |
parents | 72f725c5a7be |
children | 7666957bc44d |
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--- a/src/share/vm/gc_implementation/g1/concurrentMark.cpp Mon Apr 05 12:19:22 2010 -0400 +++ b/src/share/vm/gc_implementation/g1/concurrentMark.cpp Tue Apr 06 10:59:45 2010 -0400 @@ -708,24 +708,46 @@ // void ConcurrentMark::clearNextBitmap() { - guarantee(!G1CollectedHeap::heap()->mark_in_progress(), "Precondition."); - - // clear the mark bitmap (no grey objects to start with). - // We need to do this in chunks and offer to yield in between - // each chunk. - HeapWord* start = _nextMarkBitMap->startWord(); - HeapWord* end = _nextMarkBitMap->endWord(); - HeapWord* cur = start; - size_t chunkSize = M; - while (cur < end) { - HeapWord* next = cur + chunkSize; - if (next > end) - next = end; - MemRegion mr(cur,next); - _nextMarkBitMap->clearRange(mr); - cur = next; - do_yield_check(); - } + G1CollectedHeap* g1h = G1CollectedHeap::heap(); + G1CollectorPolicy* g1p = g1h->g1_policy(); + + // Make sure that the concurrent mark thread looks to still be in + // the current cycle. + guarantee(cmThread()->during_cycle(), "invariant"); + + // We are finishing up the current cycle by clearing the next + // marking bitmap and getting it ready for the next cycle. During + // this time no other cycle can start. So, let's make sure that this + // is the case. + guarantee(!g1h->mark_in_progress(), "invariant"); + + // clear the mark bitmap (no grey objects to start with). + // We need to do this in chunks and offer to yield in between + // each chunk. + HeapWord* start = _nextMarkBitMap->startWord(); + HeapWord* end = _nextMarkBitMap->endWord(); + HeapWord* cur = start; + size_t chunkSize = M; + while (cur < end) { + HeapWord* next = cur + chunkSize; + if (next > end) + next = end; + MemRegion mr(cur,next); + _nextMarkBitMap->clearRange(mr); + cur = next; + do_yield_check(); + + // Repeat the asserts from above. We'll do them as asserts here to + // minimize their overhead on the product. However, we'll have + // them as guarantees at the beginning / end of the bitmap + // clearing to get some checking in the product. + assert(cmThread()->during_cycle(), "invariant"); + assert(!g1h->mark_in_progress(), "invariant"); + } + + // Repeat the asserts from above. + guarantee(cmThread()->during_cycle(), "invariant"); + guarantee(!g1h->mark_in_progress(), "invariant"); } class NoteStartOfMarkHRClosure: public HeapRegionClosure {