1.1 --- a/src/share/vm/gc_implementation/g1/concurrentMark.inline.hpp Wed Apr 22 14:06:49 2015 -0400
1.2 +++ b/src/share/vm/gc_implementation/g1/concurrentMark.inline.hpp Fri May 01 17:38:12 2015 -0400
1.3 @@ -259,15 +259,15 @@
1.4 ++_local_pushes );
1.5 }
1.6
1.7 -inline bool CMTask::is_below_finger(HeapWord* objAddr,
1.8 - HeapWord* global_finger) const {
1.9 - // If objAddr is above the global finger, then the mark bitmap scan
1.10 +inline bool CMTask::is_below_finger(oop obj, HeapWord* global_finger) const {
1.11 + // If obj is above the global finger, then the mark bitmap scan
1.12 // will find it later, and no push is needed. Similarly, if we have
1.13 - // a current region and objAddr is between the local finger and the
1.14 + // a current region and obj is between the local finger and the
1.15 // end of the current region, then no push is needed. The tradeoff
1.16 // of checking both vs only checking the global finger is that the
1.17 // local check will be more accurate and so result in fewer pushes,
1.18 // but may also be a little slower.
1.19 + HeapWord* objAddr = (HeapWord*)obj;
1.20 if (_finger != NULL) {
1.21 // We have a current region.
1.22
1.23 @@ -277,7 +277,7 @@
1.24 assert(_region_limit != NULL, "invariant");
1.25 assert(_region_limit <= global_finger, "invariant");
1.26
1.27 - // True if objAddr is less than the local finger, or is between
1.28 + // True if obj is less than the local finger, or is between
1.29 // the region limit and the global finger.
1.30 if (objAddr < _finger) {
1.31 return true;
1.32 @@ -289,13 +289,65 @@
1.33 return objAddr < global_finger;
1.34 }
1.35
1.36 +inline void CMTask::make_reference_grey(oop obj, HeapRegion* hr) {
1.37 + if (_cm->par_mark_and_count(obj, hr, _marked_bytes_array, _card_bm)) {
1.38 +
1.39 + if (_cm->verbose_high()) {
1.40 + gclog_or_tty->print_cr("[%u] marked object " PTR_FORMAT,
1.41 + _worker_id, p2i(obj));
1.42 + }
1.43 +
1.44 + // No OrderAccess:store_load() is needed. It is implicit in the
1.45 + // CAS done in CMBitMap::parMark() call in the routine above.
1.46 + HeapWord* global_finger = _cm->finger();
1.47 +
1.48 + // We only need to push a newly grey object on the mark
1.49 + // stack if it is in a section of memory the mark bitmap
1.50 + // scan has already examined. Mark bitmap scanning
1.51 + // maintains progress "fingers" for determining that.
1.52 + //
1.53 + // Notice that the global finger might be moving forward
1.54 + // concurrently. This is not a problem. In the worst case, we
1.55 + // mark the object while it is above the global finger and, by
1.56 + // the time we read the global finger, it has moved forward
1.57 + // past this object. In this case, the object will probably
1.58 + // be visited when a task is scanning the region and will also
1.59 + // be pushed on the stack. So, some duplicate work, but no
1.60 + // correctness problems.
1.61 + if (is_below_finger(obj, global_finger)) {
1.62 + if (obj->is_typeArray()) {
1.63 + // Immediately process arrays of primitive types, rather
1.64 + // than pushing on the mark stack. This keeps us from
1.65 + // adding humongous objects to the mark stack that might
1.66 + // be reclaimed before the entry is processed - see
1.67 + // selection of candidates for eager reclaim of humongous
1.68 + // objects. The cost of the additional type test is
1.69 + // mitigated by avoiding a trip through the mark stack,
1.70 + // by only doing a bookkeeping update and avoiding the
1.71 + // actual scan of the object - a typeArray contains no
1.72 + // references, and the metadata is built-in.
1.73 + process_grey_object<false>(obj);
1.74 + } else {
1.75 + if (_cm->verbose_high()) {
1.76 + gclog_or_tty->print_cr("[%u] below a finger (local: " PTR_FORMAT
1.77 + ", global: " PTR_FORMAT ") pushing "
1.78 + PTR_FORMAT " on mark stack",
1.79 + _worker_id, p2i(_finger),
1.80 + p2i(global_finger), p2i(obj));
1.81 + }
1.82 + push(obj);
1.83 + }
1.84 + }
1.85 + }
1.86 +}
1.87 +
1.88 inline void CMTask::deal_with_reference(oop obj) {
1.89 if (_cm->verbose_high()) {
1.90 gclog_or_tty->print_cr("[%u] we're dealing with reference = "PTR_FORMAT,
1.91 _worker_id, p2i((void*) obj));
1.92 }
1.93
1.94 - ++_refs_reached;
1.95 + increment_refs_reached();
1.96
1.97 HeapWord* objAddr = (HeapWord*) obj;
1.98 assert(obj->is_oop_or_null(true /* ignore mark word */), "Error");
1.99 @@ -307,55 +359,7 @@
1.100 // anything with it).
1.101 HeapRegion* hr = _g1h->heap_region_containing_raw(obj);
1.102 if (!hr->obj_allocated_since_next_marking(obj)) {
1.103 - if (_cm->verbose_high()) {
1.104 - gclog_or_tty->print_cr("[%u] "PTR_FORMAT" is not considered marked",
1.105 - _worker_id, p2i((void*) obj));
1.106 - }
1.107 -
1.108 - // we need to mark it first
1.109 - if (_cm->par_mark_and_count(obj, hr, _marked_bytes_array, _card_bm)) {
1.110 - // No OrderAccess:store_load() is needed. It is implicit in the
1.111 - // CAS done in CMBitMap::parMark() call in the routine above.
1.112 - HeapWord* global_finger = _cm->finger();
1.113 -
1.114 - // We only need to push a newly grey object on the mark
1.115 - // stack if it is in a section of memory the mark bitmap
1.116 - // scan has already examined. Mark bitmap scanning
1.117 - // maintains progress "fingers" for determining that.
1.118 - //
1.119 - // Notice that the global finger might be moving forward
1.120 - // concurrently. This is not a problem. In the worst case, we
1.121 - // mark the object while it is above the global finger and, by
1.122 - // the time we read the global finger, it has moved forward
1.123 - // past this object. In this case, the object will probably
1.124 - // be visited when a task is scanning the region and will also
1.125 - // be pushed on the stack. So, some duplicate work, but no
1.126 - // correctness problems.
1.127 - if (is_below_finger(objAddr, global_finger)) {
1.128 - if (obj->is_typeArray()) {
1.129 - // Immediately process arrays of primitive types, rather
1.130 - // than pushing on the mark stack. This keeps us from
1.131 - // adding humongous objects to the mark stack that might
1.132 - // be reclaimed before the entry is processed - see
1.133 - // selection of candidates for eager reclaim of humongous
1.134 - // objects. The cost of the additional type test is
1.135 - // mitigated by avoiding a trip through the mark stack,
1.136 - // by only doing a bookkeeping update and avoiding the
1.137 - // actual scan of the object - a typeArray contains no
1.138 - // references, and the metadata is built-in.
1.139 - process_grey_object<false>(obj);
1.140 - } else {
1.141 - if (_cm->verbose_high()) {
1.142 - gclog_or_tty->print_cr("[%u] below a finger (local: " PTR_FORMAT
1.143 - ", global: " PTR_FORMAT ") pushing "
1.144 - PTR_FORMAT " on mark stack",
1.145 - _worker_id, p2i(_finger),
1.146 - p2i(global_finger), p2i(objAddr));
1.147 - }
1.148 - push(obj);
1.149 - }
1.150 - }
1.151 - }
1.152 + make_reference_grey(obj, hr);
1.153 }
1.154 }
1.155 }
