1.1 --- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Fri Jun 06 11:47:26 2008 -0700
1.2 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Mon Jun 09 11:51:19 2008 -0400
1.3 @@ -190,7 +190,8 @@
1.4 // depends on this property.
1.5 debug_only(
1.6 FreeChunk* junk = NULL;
1.7 - assert(junk->prev_addr() == (void*)(oop(junk)->klass_addr()),
1.8 + assert(UseCompressedOops ||
1.9 + junk->prev_addr() == (void*)(oop(junk)->klass_addr()),
1.10 "Offset of FreeChunk::_prev within FreeChunk must match"
1.11 " that of OopDesc::_klass within OopDesc");
1.12 )
1.13 @@ -1039,7 +1040,7 @@
1.14 // mark end of object
1.15 }
1.16 // check that oop looks uninitialized
1.17 - assert(oop(start)->klass() == NULL, "_klass should be NULL");
1.18 + assert(oop(start)->klass_or_null() == NULL, "_klass should be NULL");
1.19 }
1.20
1.21 void CMSCollector::promoted(bool par, HeapWord* start,
1.22 @@ -1309,17 +1310,25 @@
1.23 }
1.24 }
1.25 oop obj = oop(obj_ptr);
1.26 - assert(obj->klass() == NULL, "Object should be uninitialized here.");
1.27 + assert(obj->klass_or_null() == NULL, "Object should be uninitialized here.");
1.28 // Otherwise, copy the object. Here we must be careful to insert the
1.29 // klass pointer last, since this marks the block as an allocated object.
1.30 + // Except with compressed oops it's the mark word.
1.31 HeapWord* old_ptr = (HeapWord*)old;
1.32 if (word_sz > (size_t)oopDesc::header_size()) {
1.33 Copy::aligned_disjoint_words(old_ptr + oopDesc::header_size(),
1.34 obj_ptr + oopDesc::header_size(),
1.35 word_sz - oopDesc::header_size());
1.36 }
1.37 +
1.38 + if (UseCompressedOops) {
1.39 + // Copy gap missed by (aligned) header size calculation above
1.40 + obj->set_klass_gap(old->klass_gap());
1.41 + }
1.42 +
1.43 // Restore the mark word copied above.
1.44 obj->set_mark(m);
1.45 +
1.46 // Now we can track the promoted object, if necessary. We take care
1.47 // To delay the transition from uninitialized to full object
1.48 // (i.e., insertion of klass pointer) until after, so that it
1.49 @@ -1327,7 +1336,8 @@
1.50 if (promoInfo->tracking()) {
1.51 promoInfo->track((PromotedObject*)obj, old->klass());
1.52 }
1.53 - // Finally, install the klass pointer.
1.54 +
1.55 + // Finally, install the klass pointer (this should be volatile).
1.56 obj->set_klass(old->klass());
1.57
1.58 assert(old->is_oop(), "Will dereference klass ptr below");
1.59 @@ -6165,7 +6175,7 @@
1.60 HeapWord* CMSCollector::next_card_start_after_block(HeapWord* addr) const {
1.61 size_t sz = 0;
1.62 oop p = (oop)addr;
1.63 - if (p->klass() != NULL && p->is_parsable()) {
1.64 + if (p->klass_or_null() != NULL && p->is_parsable()) {
1.65 sz = CompactibleFreeListSpace::adjustObjectSize(p->size());
1.66 } else {
1.67 sz = block_size_using_printezis_bits(addr);
1.68 @@ -6602,7 +6612,7 @@
1.69 }
1.70 if (_bitMap->isMarked(addr)) {
1.71 // it's marked; is it potentially uninitialized?
1.72 - if (p->klass() != NULL) {
1.73 + if (p->klass_or_null() != NULL) {
1.74 if (CMSPermGenPrecleaningEnabled && !p->is_parsable()) {
1.75 // Signal precleaning to redirty the card since
1.76 // the klass pointer is already installed.
1.77 @@ -6615,11 +6625,8 @@
1.78 if (p->is_objArray()) {
1.79 // objArrays are precisely marked; restrict scanning
1.80 // to dirty cards only.
1.81 - size = p->oop_iterate(_scanningClosure, mr);
1.82 - assert(size == CompactibleFreeListSpace::adjustObjectSize(size),
1.83 - "adjustObjectSize should be the identity for array sizes, "
1.84 - "which are necessarily larger than minimum object size of "
1.85 - "two heap words");
1.86 + size = CompactibleFreeListSpace::adjustObjectSize(
1.87 + p->oop_iterate(_scanningClosure, mr));
1.88 } else {
1.89 // A non-array may have been imprecisely marked; we need
1.90 // to scan object in its entirety.
1.91 @@ -6653,7 +6660,7 @@
1.92 }
1.93 } else {
1.94 // Either a not yet marked object or an uninitialized object
1.95 - if (p->klass() == NULL || !p->is_parsable()) {
1.96 + if (p->klass_or_null() == NULL || !p->is_parsable()) {
1.97 // An uninitialized object, skip to the next card, since
1.98 // we may not be able to read its P-bits yet.
1.99 assert(size == 0, "Initial value");
1.100 @@ -6710,7 +6717,7 @@
1.101 HeapWord* addr = (HeapWord*)p;
1.102 DEBUG_ONLY(_collector->verify_work_stacks_empty();)
1.103 assert(!_span.contains(addr), "we are scanning the survivor spaces");
1.104 - assert(p->klass() != NULL, "object should be initializd");
1.105 + assert(p->klass_or_null() != NULL, "object should be initializd");
1.106 assert(p->is_parsable(), "must be parsable.");
1.107 // an initialized object; ignore mark word in verification below
1.108 // since we are running concurrent with mutators
1.109 @@ -6868,7 +6875,7 @@
1.110 assert(_skipBits == 0, "tautology");
1.111 _skipBits = 2; // skip next two marked bits ("Printezis-marks")
1.112 oop p = oop(addr);
1.113 - if (p->klass() == NULL || !p->is_parsable()) {
1.114 + if (p->klass_or_null() == NULL || !p->is_parsable()) {
1.115 DEBUG_ONLY(if (!_verifying) {)
1.116 // We re-dirty the cards on which this object lies and increase
1.117 // the _threshold so that we'll come back to scan this object
1.118 @@ -6890,7 +6897,7 @@
1.119 if (_threshold < end_card_addr) {
1.120 _threshold = end_card_addr;
1.121 }
1.122 - if (p->klass() != NULL) {
1.123 + if (p->klass_or_null() != NULL) {
1.124 // Redirty the range of cards...
1.125 _mut->mark_range(redirty_range);
1.126 } // ...else the setting of klass will dirty the card anyway.
1.127 @@ -7048,7 +7055,7 @@
1.128 assert(_skip_bits == 0, "tautology");
1.129 _skip_bits = 2; // skip next two marked bits ("Printezis-marks")
1.130 oop p = oop(addr);
1.131 - if (p->klass() == NULL || !p->is_parsable()) {
1.132 + if (p->klass_or_null() == NULL || !p->is_parsable()) {
1.133 // in the case of Clean-on-Enter optimization, redirty card
1.134 // and avoid clearing card by increasing the threshold.
1.135 return;
1.136 @@ -8023,7 +8030,7 @@
1.137 "alignment problem");
1.138
1.139 #ifdef DEBUG
1.140 - if (oop(addr)->klass() != NULL &&
1.141 + if (oop(addr)->klass_or_null() != NULL &&
1.142 ( !_collector->should_unload_classes()
1.143 || oop(addr)->is_parsable())) {
1.144 // Ignore mark word because we are running concurrent with mutators
1.145 @@ -8036,7 +8043,7 @@
1.146
1.147 } else {
1.148 // This should be an initialized object that's alive.
1.149 - assert(oop(addr)->klass() != NULL &&
1.150 + assert(oop(addr)->klass_or_null() != NULL &&
1.151 (!_collector->should_unload_classes()
1.152 || oop(addr)->is_parsable()),
1.153 "Should be an initialized object");
