src/share/vm/gc_implementation/g1/heapRegion.inline.hpp

Thu, 07 Apr 2011 09:53:20 -0700

author
johnc
date
Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781
e1162778c1c8
parent 2715
abdfc822206f
child 3416
2ace1c4ee8da
permissions
-rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

ysr@777 1 /*
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ysr@777 7 * published by the Free Software Foundation.
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ysr@777 24
stefank@2314 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP
stefank@2314 26 #define SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP
stefank@2314 27
ysr@777 28 inline HeapWord* G1OffsetTableContigSpace::allocate(size_t size) {
ysr@777 29 HeapWord* res = ContiguousSpace::allocate(size);
ysr@777 30 if (res != NULL) {
ysr@777 31 _offsets.alloc_block(res, size);
ysr@777 32 }
ysr@777 33 return res;
ysr@777 34 }
ysr@777 35
ysr@777 36 // Because of the requirement of keeping "_offsets" up to date with the
ysr@777 37 // allocations, we sequentialize these with a lock. Therefore, best if
ysr@777 38 // this is used for larger LAB allocations only.
ysr@777 39 inline HeapWord* G1OffsetTableContigSpace::par_allocate(size_t size) {
ysr@777 40 MutexLocker x(&_par_alloc_lock);
tonyp@2715 41 // Given that we take the lock no need to use par_allocate() here.
tonyp@2715 42 HeapWord* res = ContiguousSpace::allocate(size);
ysr@777 43 if (res != NULL) {
ysr@777 44 _offsets.alloc_block(res, size);
ysr@777 45 }
ysr@777 46 return res;
ysr@777 47 }
ysr@777 48
ysr@777 49 inline HeapWord* G1OffsetTableContigSpace::block_start(const void* p) {
ysr@777 50 return _offsets.block_start(p);
ysr@777 51 }
ysr@777 52
ysr@777 53 inline HeapWord*
ysr@777 54 G1OffsetTableContigSpace::block_start_const(const void* p) const {
ysr@777 55 return _offsets.block_start_const(p);
ysr@777 56 }
stefank@2314 57
stefank@2314 58 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_HEAPREGION_INLINE_HPP

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