src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp
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rev 5917 : [mq]: cleanup-parcopyclosure
*** 696,722 ****
assert(!_in_cset_fast_test_base[index], "invariant");
_in_cset_fast_test_base[index] = true;
}
// This is a fast test on whether a reference points into the
! // collection set or not. It does not assume that the reference
! // points into the heap; if it doesn't, it will return false.
bool in_cset_fast_test(oop obj) {
assert(_in_cset_fast_test != NULL, "sanity");
! if (_g1_committed.contains((HeapWord*) obj)) {
// no need to subtract the bottom of the heap from obj,
// _in_cset_fast_test is biased
uintx index = cast_from_oop<uintx>(obj) >> HeapRegion::LogOfHRGrainBytes;
bool ret = _in_cset_fast_test[index];
// let's make sure the result is consistent with what the slower
// test returns
assert( ret || !obj_in_cs(obj), "sanity");
assert(!ret || obj_in_cs(obj), "sanity");
return ret;
- } else {
- return false;
- }
}
void clear_cset_fast_test() {
assert(_in_cset_fast_test_base != NULL, "sanity");
memset(_in_cset_fast_test_base, false,
--- 696,719 ----
assert(!_in_cset_fast_test_base[index], "invariant");
_in_cset_fast_test_base[index] = true;
}
// This is a fast test on whether a reference points into the
! // collection set or not. Assume that the reference
! // points into the heap.
bool in_cset_fast_test(oop obj) {
assert(_in_cset_fast_test != NULL, "sanity");
! assert(_g1_committed.contains((HeapWord*) obj), "invariant");
// no need to subtract the bottom of the heap from obj,
// _in_cset_fast_test is biased
uintx index = cast_from_oop<uintx>(obj) >> HeapRegion::LogOfHRGrainBytes;
bool ret = _in_cset_fast_test[index];
// let's make sure the result is consistent with what the slower
// test returns
assert( ret || !obj_in_cs(obj), "sanity");
assert(!ret || obj_in_cs(obj), "sanity");
return ret;
}
void clear_cset_fast_test() {
assert(_in_cset_fast_test_base != NULL, "sanity");
memset(_in_cset_fast_test_base, false,
*** 1879,1891 ****
ageTable _age_table;
size_t _alloc_buffer_waste;
size_t _undo_waste;
OopsInHeapRegionClosure* _evac_failure_cl;
- G1ParScanHeapEvacClosure* _evac_cl;
- G1ParScanPartialArrayClosure* _partial_scan_cl;
int _hash_seed;
uint _queue_num;
size_t _term_attempts;
--- 1876,1887 ----
ageTable _age_table;
size_t _alloc_buffer_waste;
size_t _undo_waste;
+ G1ParScanClosure _scanner;
OopsInHeapRegionClosure* _evac_failure_cl;
int _hash_seed;
uint _queue_num;
size_t _term_attempts;
*** 1928,1938 ****
}
}
}
public:
! G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num);
~G1ParScanThreadState() {
FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
}
--- 1924,1934 ----
}
}
}
public:
! G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
~G1ParScanThreadState() {
FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
}
*** 2007,2024 ****
}
OopsInHeapRegionClosure* evac_failure_closure() {
return _evac_failure_cl;
}
- void set_evac_closure(G1ParScanHeapEvacClosure* evac_cl) {
- _evac_cl = evac_cl;
- }
-
- void set_partial_scan_closure(G1ParScanPartialArrayClosure* partial_scan_cl) {
- _partial_scan_cl = partial_scan_cl;
- }
-
int* hash_seed() { return &_hash_seed; }
uint queue_num() { return _queue_num; }
size_t term_attempts() const { return _term_attempts; }
void note_term_attempt() { _term_attempts++; }
--- 2003,2012 ----
*** 2063,2082 ****
true /* end_of_gc */,
false /* retain */);
}
}
! template <class T> void deal_with_reference(T* ref_to_scan) {
! if (has_partial_array_mask(ref_to_scan)) {
! _partial_scan_cl->do_oop_nv(ref_to_scan);
} else {
// Note: we can use "raw" versions of "region_containing" because
// "obj_to_scan" is definitely in the heap, and is not in a
// humongous region.
HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
! _evac_cl->set_region(r);
! _evac_cl->do_oop_nv(ref_to_scan);
}
}
void deal_with_reference(StarTask ref) {
assert(verify_task(ref), "sanity");
--- 2051,2189 ----
true /* end_of_gc */,
false /* retain */);
}
}
! private:
! #define G1_PARTIAL_ARRAY_MASK 0x2
!
! inline bool has_partial_array_mask(oop* const ref) const {
! return ((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) == G1_PARTIAL_ARRAY_MASK;
! }
!
! // We never encode partial array oops as narrowOop*, so return false immediately.
! // This allows the compiler to create optimized code when popping references from
! // the work queue.
! inline bool has_partial_array_mask(narrowOop* const ref) const {
! assert(((uintptr_t)ref & G1_PARTIAL_ARRAY_MASK) != G1_PARTIAL_ARRAY_MASK, "Partial array oop reference encoded as narrowOop*");
! return false;
! }
!
! // Only implement set_partial_array_mask() for regular oops, not for narrowOops.
! // We always encode partial arrays as regular oop, to allow the
! // specialization for has_partial_array_mask() for narrowOops above.
! // This means that unintentional use of this method with narrowOops are caught
! // by the compiler.
! inline oop* set_partial_array_mask(oop obj) {
! assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
! return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
! }
!
! // We always encode continuations as oop*, so we only need clear_partial_array_mask()
! // with an oop* parameter.
! inline oop clear_partial_array_mask(oop* ref) const {
! return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
! }
!
! static int min_array_chunking_size() {
! return 2 * ParGCArrayScanChunk;
! }
!
! static bool obj_needs_chunking(oop obj, size_t word_size) {
! return (word_size > (size_t)min_array_chunking_size()) && obj->is_objArray();
! }
!
! void do_oop_partial_array(oop* p) {
! assert(has_partial_array_mask(p), "invariant");
! oop from_obj = clear_partial_array_mask(p);
!
! assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap.");
! assert(from_obj->is_objArray(), "must be obj array");
! objArrayOop from_obj_array = objArrayOop(from_obj);
! // The from-space object contains the real length.
! int length = from_obj_array->length();
!
! assert(from_obj->is_forwarded(), "must be forwarded");
! oop to_obj = from_obj->forwardee();
! assert(from_obj != to_obj, "should not be chunking self-forwarded objects");
! objArrayOop to_obj_array = objArrayOop(to_obj);
! // We keep track of the next start index in the length field of the
! // to-space object.
! int next_index = to_obj_array->length();
! assert(0 <= next_index && next_index < length,
! err_msg("invariant, next index: %d, length: %d", next_index, length));
!
! int start = next_index;
! int end = length;
! assert(start <= end, "invariant");
! int remainder = end - start;
! // We'll try not to push a range that's smaller than ParGCArrayScanChunk.
! if (remainder > min_array_chunking_size()) {
! end = start + ParGCArrayScanChunk;
! to_obj_array->set_length(end);
! // Push the remainder before we process the range in case another
! // worker has run out of things to do and can steal it.
! oop* from_obj_p = set_partial_array_mask(from_obj);
! push_on_queue(from_obj_p);
} else {
+ assert(length == end, "sanity");
+ // We'll process the final range for this object. Restore the length
+ // so that the heap remains parsable in case of evacuation failure.
+ to_obj_array->set_length(end);
+ }
+ _scanner.set_region(_g1h->heap_region_containing_raw(to_obj));
+ // Process indexes [start,end). It will also process the header
+ // along with the first chunk (i.e., the chunk with start == 0).
+ // Note that at this point the length field of to_obj_array is not
+ // correct given that we are using it to keep track of the next
+ // start index. oop_iterate_range() (thankfully!) ignores the length
+ // field and only relies on the start / end parameters. It does
+ // however return the size of the object which will be incorrect. So
+ // we have to ignore it even if we wanted to use it.
+ to_obj_array->oop_iterate_range(&_scanner, start, end);
+ }
+
+ // This method is applied to the fields of the objects that have just been copied.
+ template <class T> void do_oop_evac(T* p, HeapRegion* from) {
+ assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)),
+ "Reference should not be NULL here as such are never pushed to the task queue.");
+ oop obj = oopDesc::load_decode_heap_oop_not_null(p);
+
+ // Although we never intentionally push references outside of the collection
+ // set, due to (benign) races in the claim mechanism during RSet scanning more
+ // than one thread might claim the same card. So the same card may be
+ // processed multiple times. So redo this check.
+ if (_g1h->in_cset_fast_test(obj)) {
+ oop forwardee;
+ if (obj->is_forwarded()) {
+ forwardee = obj->forwardee();
+ } else {
+ forwardee = copy_to_survivor_space(obj);
+ }
+ assert(forwardee != NULL, "forwardee should not be NULL");
+ oopDesc::encode_store_heap_oop(p, forwardee);
+ }
+
+ assert(obj != NULL, "Must be");
+ update_rs(from, p, queue_num());
+ }
+
+ public:
+
+ oop copy_to_survivor_space(oop old);
+
+ template <class T> void deal_with_reference(T* ref_to_scan) {
+ if (!has_partial_array_mask(ref_to_scan)) {
// Note: we can use "raw" versions of "region_containing" because
// "obj_to_scan" is definitely in the heap, and is not in a
// humongous region.
HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan);
! do_oop_evac(ref_to_scan, r);
! } else {
! // Partial arrays are always encoded as oop*. Cast here to avoid generating
! // the superfluous additional method.
! do_oop_partial_array((oop*)ref_to_scan);
}
}
void deal_with_reference(StarTask ref) {
assert(verify_task(ref), "sanity");