提交 e49ff7e1 编写于 作者: T tschatzl

8035400: Move G1ParScanThreadState into its own files

Summary: Extract the G1ParScanThreadState class from G1CollectedHeap.?pp into its own files.
Reviewed-by: brutisso, mgerdin
上级 76058dca
......@@ -42,6 +42,7 @@
#include "gc_implementation/g1/g1Log.hpp"
#include "gc_implementation/g1/g1MarkSweep.hpp"
#include "gc_implementation/g1/g1OopClosures.inline.hpp"
#include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/g1StringDedup.hpp"
#include "gc_implementation/g1/g1YCTypes.hpp"
......@@ -60,10 +61,8 @@
#include "memory/referenceProcessor.hpp"
#include "oops/oop.inline.hpp"
#include "oops/oop.pcgc.inline.hpp"
#include "runtime/prefetch.inline.hpp"
#include "runtime/orderAccess.inline.hpp"
#include "runtime/vmThread.hpp"
#include "utilities/ticks.hpp"
size_t G1CollectedHeap::_humongous_object_threshold_in_words = 0;
......@@ -4568,126 +4567,6 @@ HeapWord* G1CollectedHeap::par_allocate_during_gc(GCAllocPurpose purpose,
G1ParGCAllocBuffer::G1ParGCAllocBuffer(size_t gclab_word_size) :
ParGCAllocBuffer(gclab_word_size), _retired(true) { }
G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
: _g1h(g1h),
_refs(g1h->task_queue(queue_num)),
_dcq(&g1h->dirty_card_queue_set()),
_ct_bs(g1h->g1_barrier_set()),
_g1_rem(g1h->g1_rem_set()),
_hash_seed(17), _queue_num(queue_num),
_term_attempts(0),
_surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
_tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
_age_table(false), _scanner(g1h, this, rp),
_strong_roots_time(0), _term_time(0),
_alloc_buffer_waste(0), _undo_waste(0) {
// we allocate G1YoungSurvRateNumRegions plus one entries, since
// we "sacrifice" entry 0 to keep track of surviving bytes for
// non-young regions (where the age is -1)
// We also add a few elements at the beginning and at the end in
// an attempt to eliminate cache contention
uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
uint array_length = PADDING_ELEM_NUM +
real_length +
PADDING_ELEM_NUM;
_surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
if (_surviving_young_words_base == NULL)
vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
"Not enough space for young surv histo.");
_surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
_alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
_alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
_start = os::elapsedTime();
}
void
G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
{
st->print_raw_cr("GC Termination Stats");
st->print_raw_cr(" elapsed --strong roots-- -------termination-------"
" ------waste (KiB)------");
st->print_raw_cr("thr ms ms % ms % attempts"
" total alloc undo");
st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
" ------- ------- -------");
}
void
G1ParScanThreadState::print_termination_stats(int i,
outputStream* const st) const
{
const double elapsed_ms = elapsed_time() * 1000.0;
const double s_roots_ms = strong_roots_time() * 1000.0;
const double term_ms = term_time() * 1000.0;
st->print_cr("%3d %9.2f %9.2f %6.2f "
"%9.2f %6.2f " SIZE_FORMAT_W(8) " "
SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
(alloc_buffer_waste() + undo_waste()) * HeapWordSize / K,
alloc_buffer_waste() * HeapWordSize / K,
undo_waste() * HeapWordSize / K);
}
#ifdef ASSERT
bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
assert(ref != NULL, "invariant");
assert(UseCompressedOops, "sanity");
assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, ref));
oop p = oopDesc::load_decode_heap_oop(ref);
assert(_g1h->is_in_g1_reserved(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
return true;
}
bool G1ParScanThreadState::verify_ref(oop* ref) const {
assert(ref != NULL, "invariant");
if (has_partial_array_mask(ref)) {
// Must be in the collection set--it's already been copied.
oop p = clear_partial_array_mask(ref);
assert(_g1h->obj_in_cs(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
} else {
oop p = oopDesc::load_decode_heap_oop(ref);
assert(_g1h->is_in_g1_reserved(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, ref, (void *)p));
}
return true;
}
bool G1ParScanThreadState::verify_task(StarTask ref) const {
if (ref.is_narrow()) {
return verify_ref((narrowOop*) ref);
} else {
return verify_ref((oop*) ref);
}
}
#endif // ASSERT
void G1ParScanThreadState::trim_queue() {
assert(_evac_failure_cl != NULL, "not set");
StarTask ref;
do {
// Drain the overflow stack first, so other threads can steal.
while (refs()->pop_overflow(ref)) {
deal_with_reference(ref);
}
while (refs()->pop_local(ref)) {
deal_with_reference(ref);
}
} while (!refs()->is_empty());
}
G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1,
G1ParScanThreadState* par_scan_state) :
_g1(g1), _par_scan_state(par_scan_state),
_worker_id(par_scan_state->queue_num()) { }
void G1ParCopyHelper::mark_object(oop obj) {
#ifdef ASSERT
HeapRegion* hr = _g1->heap_region_containing(obj);
......@@ -4721,107 +4600,6 @@ void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
_cm->grayRoot(to_obj, (size_t) from_obj->size(), _worker_id);
}
oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
size_t word_sz = old->size();
HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
// +1 to make the -1 indexes valid...
int young_index = from_region->young_index_in_cset()+1;
assert( (from_region->is_young() && young_index > 0) ||
(!from_region->is_young() && young_index == 0), "invariant" );
G1CollectorPolicy* g1p = _g1h->g1_policy();
markOop m = old->mark();
int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
: m->age();
GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
word_sz);
HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
#ifndef PRODUCT
// Should this evacuation fail?
if (_g1h->evacuation_should_fail()) {
if (obj_ptr != NULL) {
undo_allocation(alloc_purpose, obj_ptr, word_sz);
obj_ptr = NULL;
}
}
#endif // !PRODUCT
if (obj_ptr == NULL) {
// This will either forward-to-self, or detect that someone else has
// installed a forwarding pointer.
return _g1h->handle_evacuation_failure_par(this, old);
}
oop obj = oop(obj_ptr);
// We're going to allocate linearly, so might as well prefetch ahead.
Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
oop forward_ptr = old->forward_to_atomic(obj);
if (forward_ptr == NULL) {
Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
// alloc_purpose is just a hint to allocate() above, recheck the type of region
// we actually allocated from and update alloc_purpose accordingly
HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
if (g1p->track_object_age(alloc_purpose)) {
// We could simply do obj->incr_age(). However, this causes a
// performance issue. obj->incr_age() will first check whether
// the object has a displaced mark by checking its mark word;
// getting the mark word from the new location of the object
// stalls. So, given that we already have the mark word and we
// are about to install it anyway, it's better to increase the
// age on the mark word, when the object does not have a
// displaced mark word. We're not expecting many objects to have
// a displaced marked word, so that case is not optimized
// further (it could be...) and we simply call obj->incr_age().
if (m->has_displaced_mark_helper()) {
// in this case, we have to install the mark word first,
// otherwise obj looks to be forwarded (the old mark word,
// which contains the forward pointer, was copied)
obj->set_mark(m);
obj->incr_age();
} else {
m = m->incr_age();
obj->set_mark(m);
}
age_table()->add(obj, word_sz);
} else {
obj->set_mark(m);
}
if (G1StringDedup::is_enabled()) {
G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
to_region->is_young(),
queue_num(),
obj);
}
size_t* surv_young_words = surviving_young_words();
surv_young_words[young_index] += word_sz;
if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
// We keep track of the next start index in the length field of
// the to-space object. The actual length can be found in the
// length field of the from-space object.
arrayOop(obj)->set_length(0);
oop* old_p = set_partial_array_mask(old);
push_on_queue(old_p);
} else {
// No point in using the slower heap_region_containing() method,
// given that we know obj is in the heap.
_scanner.set_region(_g1h->heap_region_containing_raw(obj));
obj->oop_iterate_backwards(&_scanner);
}
} else {
undo_allocation(alloc_purpose, obj_ptr, word_sz);
obj = forward_ptr;
}
return obj;
}
template <class T>
void G1ParCopyHelper::do_klass_barrier(T* p, oop new_obj) {
if (_g1->heap_region_containing_raw(new_obj)->is_young()) {
......
......@@ -31,7 +31,6 @@
#include "gc_implementation/g1/g1BiasedArray.hpp"
#include "gc_implementation/g1/g1HRPrinter.hpp"
#include "gc_implementation/g1/g1MonitoringSupport.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/g1YCTypes.hpp"
#include "gc_implementation/g1/heapRegionSeq.hpp"
......@@ -1709,256 +1708,4 @@ public:
}
};
class G1ParScanThreadState : public StackObj {
protected:
G1CollectedHeap* _g1h;
RefToScanQueue* _refs;
DirtyCardQueue _dcq;
G1SATBCardTableModRefBS* _ct_bs;
G1RemSet* _g1_rem;
G1ParGCAllocBuffer _surviving_alloc_buffer;
G1ParGCAllocBuffer _tenured_alloc_buffer;
G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
ageTable _age_table;
G1ParScanClosure _scanner;
size_t _alloc_buffer_waste;
size_t _undo_waste;
OopsInHeapRegionClosure* _evac_failure_cl;
int _hash_seed;
uint _queue_num;
size_t _term_attempts;
double _start;
double _start_strong_roots;
double _strong_roots_time;
double _start_term;
double _term_time;
// Map from young-age-index (0 == not young, 1 is youngest) to
// surviving words. base is what we get back from the malloc call
size_t* _surviving_young_words_base;
// this points into the array, as we use the first few entries for padding
size_t* _surviving_young_words;
#define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
void add_to_undo_waste(size_t waste) { _undo_waste += waste; }
DirtyCardQueue& dirty_card_queue() { return _dcq; }
G1SATBCardTableModRefBS* ctbs() { return _ct_bs; }
template <class T> inline void immediate_rs_update(HeapRegion* from, T* p, int tid);
template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) {
// If the new value of the field points to the same region or
// is the to-space, we don't need to include it in the Rset updates.
if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
size_t card_index = ctbs()->index_for(p);
// If the card hasn't been added to the buffer, do it.
if (ctbs()->mark_card_deferred(card_index)) {
dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
}
}
}
public:
G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
~G1ParScanThreadState() {
retire_alloc_buffers();
FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
}
RefToScanQueue* refs() { return _refs; }
ageTable* age_table() { return &_age_table; }
G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
return _alloc_buffers[purpose];
}
size_t alloc_buffer_waste() const { return _alloc_buffer_waste; }
size_t undo_waste() const { return _undo_waste; }
#ifdef ASSERT
bool verify_ref(narrowOop* ref) const;
bool verify_ref(oop* ref) const;
bool verify_task(StarTask ref) const;
#endif // ASSERT
template <class T> void push_on_queue(T* ref) {
assert(verify_ref(ref), "sanity");
refs()->push(ref);
}
template <class T> inline void update_rs(HeapRegion* from, T* p, int tid);
HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
HeapWord* obj = NULL;
size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
add_to_alloc_buffer_waste(alloc_buf->words_remaining());
alloc_buf->retire(false /* end_of_gc */, false /* retain */);
HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
if (buf == NULL) return NULL; // Let caller handle allocation failure.
// Otherwise.
alloc_buf->set_word_size(gclab_word_size);
alloc_buf->set_buf(buf);
obj = alloc_buf->allocate(word_sz);
assert(obj != NULL, "buffer was definitely big enough...");
} else {
obj = _g1h->par_allocate_during_gc(purpose, word_sz);
}
return obj;
}
HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) {
HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
if (obj != NULL) return obj;
return allocate_slow(purpose, word_sz);
}
void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
if (alloc_buffer(purpose)->contains(obj)) {
assert(alloc_buffer(purpose)->contains(obj + word_sz - 1),
"should contain whole object");
alloc_buffer(purpose)->undo_allocation(obj, word_sz);
} else {
CollectedHeap::fill_with_object(obj, word_sz);
add_to_undo_waste(word_sz);
}
}
void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
_evac_failure_cl = evac_failure_cl;
}
OopsInHeapRegionClosure* evac_failure_closure() {
return _evac_failure_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++; }
void start_strong_roots() {
_start_strong_roots = os::elapsedTime();
}
void end_strong_roots() {
_strong_roots_time += (os::elapsedTime() - _start_strong_roots);
}
double strong_roots_time() const { return _strong_roots_time; }
void start_term_time() {
note_term_attempt();
_start_term = os::elapsedTime();
}
void end_term_time() {
_term_time += (os::elapsedTime() - _start_term);
}
double term_time() const { return _term_time; }
double elapsed_time() const {
return os::elapsedTime() - _start;
}
static void
print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
void
print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
size_t* surviving_young_words() {
// We add on to hide entry 0 which accumulates surviving words for
// age -1 regions (i.e. non-young ones)
return _surviving_young_words;
}
private:
void retire_alloc_buffers() {
for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
size_t waste = _alloc_buffers[ap]->words_remaining();
add_to_alloc_buffer_waste(waste);
_alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
true /* end_of_gc */,
false /* retain */);
}
}
#define G1_PARTIAL_ARRAY_MASK 0x2
inline bool has_partial_array_mask(oop* 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* 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) const {
assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
}
inline oop clear_partial_array_mask(oop* ref) const {
return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
}
inline void do_oop_partial_array(oop* p);
// 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 const obj);
template <class T> inline void deal_with_reference(T* ref_to_scan);
inline void deal_with_reference(StarTask ref);
public:
void trim_queue();
};
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_HPP
......@@ -29,7 +29,6 @@
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1AllocRegion.inline.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/heapRegionSet.inline.hpp"
#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
......@@ -291,89 +290,4 @@ inline bool G1CollectedHeap::is_obj_ill(const oop obj) const {
else return is_obj_ill(obj, hr);
}
template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) {
if (!from->is_survivor()) {
_g1_rem->par_write_ref(from, p, tid);
}
}
template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) {
if (G1DeferredRSUpdate) {
deferred_rs_update(from, p, tid);
} else {
immediate_rs_update(from, p, tid);
}
}
inline void G1ParScanThreadState::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;
int remainder = end - start;
// We'll try not to push a range that's smaller than ParGCArrayScanChunk.
if (remainder > 2 * ParGCArrayScanChunk) {
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);
}
template <class T> inline void G1ParScanThreadState::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 {
do_oop_partial_array((oop*)ref_to_scan);
}
}
inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
assert(verify_task(ref), "sanity");
if (ref.is_narrow()) {
deal_with_reference((narrowOop*)ref);
} else {
deal_with_reference((oop*)ref);
}
}
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1COLLECTEDHEAP_INLINE_HPP
......@@ -29,3 +29,7 @@
G1ParCopyHelper::G1ParCopyHelper(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state) :
G1ParClosureSuper(g1, par_scan_state), _scanned_klass(NULL),
_cm(_g1->concurrent_mark()) {}
G1ParClosureSuper::G1ParClosureSuper(G1CollectedHeap* g1, G1ParScanThreadState* par_scan_state) :
_g1(g1), _par_scan_state(par_scan_state),
_worker_id(par_scan_state->queue_num()) { }
......@@ -28,6 +28,7 @@
#include "gc_implementation/g1/concurrentMark.inline.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1OopClosures.hpp"
#include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "gc_implementation/g1/heapRegionRemSet.hpp"
......
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#include "precompiled.hpp"
#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
#include "gc_implementation/g1/g1OopClosures.inline.hpp"
#include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
#include "oops/oop.inline.hpp"
#include "oops/oop.pcgc.inline.hpp"
#include "runtime/prefetch.inline.hpp"
#ifdef _MSC_VER // the use of 'this' below gets a warning, make it go away
#pragma warning( disable:4355 ) // 'this' : used in base member initializer list
#endif // _MSC_VER
G1ParScanThreadState::G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp)
: _g1h(g1h),
_refs(g1h->task_queue(queue_num)),
_dcq(&g1h->dirty_card_queue_set()),
_ct_bs(g1h->g1_barrier_set()),
_g1_rem(g1h->g1_rem_set()),
_hash_seed(17), _queue_num(queue_num),
_term_attempts(0),
_surviving_alloc_buffer(g1h->desired_plab_sz(GCAllocForSurvived)),
_tenured_alloc_buffer(g1h->desired_plab_sz(GCAllocForTenured)),
_age_table(false), _scanner(g1h, this, rp),
_strong_roots_time(0), _term_time(0),
_alloc_buffer_waste(0), _undo_waste(0) {
// we allocate G1YoungSurvRateNumRegions plus one entries, since
// we "sacrifice" entry 0 to keep track of surviving bytes for
// non-young regions (where the age is -1)
// We also add a few elements at the beginning and at the end in
// an attempt to eliminate cache contention
uint real_length = 1 + _g1h->g1_policy()->young_cset_region_length();
uint array_length = PADDING_ELEM_NUM +
real_length +
PADDING_ELEM_NUM;
_surviving_young_words_base = NEW_C_HEAP_ARRAY(size_t, array_length, mtGC);
if (_surviving_young_words_base == NULL)
vm_exit_out_of_memory(array_length * sizeof(size_t), OOM_MALLOC_ERROR,
"Not enough space for young surv histo.");
_surviving_young_words = _surviving_young_words_base + PADDING_ELEM_NUM;
memset(_surviving_young_words, 0, (size_t) real_length * sizeof(size_t));
_alloc_buffers[GCAllocForSurvived] = &_surviving_alloc_buffer;
_alloc_buffers[GCAllocForTenured] = &_tenured_alloc_buffer;
_start = os::elapsedTime();
}
void
G1ParScanThreadState::print_termination_stats_hdr(outputStream* const st)
{
st->print_raw_cr("GC Termination Stats");
st->print_raw_cr(" elapsed --strong roots-- -------termination-------"
" ------waste (KiB)------");
st->print_raw_cr("thr ms ms % ms % attempts"
" total alloc undo");
st->print_raw_cr("--- --------- --------- ------ --------- ------ --------"
" ------- ------- -------");
}
void
G1ParScanThreadState::print_termination_stats(int i,
outputStream* const st) const
{
const double elapsed_ms = elapsed_time() * 1000.0;
const double s_roots_ms = strong_roots_time() * 1000.0;
const double term_ms = term_time() * 1000.0;
st->print_cr("%3d %9.2f %9.2f %6.2f "
"%9.2f %6.2f " SIZE_FORMAT_W(8) " "
SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7) " " SIZE_FORMAT_W(7),
i, elapsed_ms, s_roots_ms, s_roots_ms * 100 / elapsed_ms,
term_ms, term_ms * 100 / elapsed_ms, term_attempts(),
(alloc_buffer_waste() + undo_waste()) * HeapWordSize / K,
alloc_buffer_waste() * HeapWordSize / K,
undo_waste() * HeapWordSize / K);
}
#ifdef ASSERT
bool G1ParScanThreadState::verify_ref(narrowOop* ref) const {
assert(ref != NULL, "invariant");
assert(UseCompressedOops, "sanity");
assert(!has_partial_array_mask(ref), err_msg("ref=" PTR_FORMAT, p2i(ref)));
oop p = oopDesc::load_decode_heap_oop(ref);
assert(_g1h->is_in_g1_reserved(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
return true;
}
bool G1ParScanThreadState::verify_ref(oop* ref) const {
assert(ref != NULL, "invariant");
if (has_partial_array_mask(ref)) {
// Must be in the collection set--it's already been copied.
oop p = clear_partial_array_mask(ref);
assert(_g1h->obj_in_cs(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
} else {
oop p = oopDesc::load_decode_heap_oop(ref);
assert(_g1h->is_in_g1_reserved(p),
err_msg("ref=" PTR_FORMAT " p=" PTR_FORMAT, p2i(ref), p2i(p)));
}
return true;
}
bool G1ParScanThreadState::verify_task(StarTask ref) const {
if (ref.is_narrow()) {
return verify_ref((narrowOop*) ref);
} else {
return verify_ref((oop*) ref);
}
}
#endif // ASSERT
void G1ParScanThreadState::trim_queue() {
assert(_evac_failure_cl != NULL, "not set");
StarTask ref;
do {
// Drain the overflow stack first, so other threads can steal.
while (refs()->pop_overflow(ref)) {
deal_with_reference(ref);
}
while (refs()->pop_local(ref)) {
deal_with_reference(ref);
}
} while (!refs()->is_empty());
}
oop G1ParScanThreadState::copy_to_survivor_space(oop const old) {
size_t word_sz = old->size();
HeapRegion* from_region = _g1h->heap_region_containing_raw(old);
// +1 to make the -1 indexes valid...
int young_index = from_region->young_index_in_cset()+1;
assert( (from_region->is_young() && young_index > 0) ||
(!from_region->is_young() && young_index == 0), "invariant" );
G1CollectorPolicy* g1p = _g1h->g1_policy();
markOop m = old->mark();
int age = m->has_displaced_mark_helper() ? m->displaced_mark_helper()->age()
: m->age();
GCAllocPurpose alloc_purpose = g1p->evacuation_destination(from_region, age,
word_sz);
HeapWord* obj_ptr = allocate(alloc_purpose, word_sz);
#ifndef PRODUCT
// Should this evacuation fail?
if (_g1h->evacuation_should_fail()) {
if (obj_ptr != NULL) {
undo_allocation(alloc_purpose, obj_ptr, word_sz);
obj_ptr = NULL;
}
}
#endif // !PRODUCT
if (obj_ptr == NULL) {
// This will either forward-to-self, or detect that someone else has
// installed a forwarding pointer.
return _g1h->handle_evacuation_failure_par(this, old);
}
oop obj = oop(obj_ptr);
// We're going to allocate linearly, so might as well prefetch ahead.
Prefetch::write(obj_ptr, PrefetchCopyIntervalInBytes);
oop forward_ptr = old->forward_to_atomic(obj);
if (forward_ptr == NULL) {
Copy::aligned_disjoint_words((HeapWord*) old, obj_ptr, word_sz);
// alloc_purpose is just a hint to allocate() above, recheck the type of region
// we actually allocated from and update alloc_purpose accordingly
HeapRegion* to_region = _g1h->heap_region_containing_raw(obj_ptr);
alloc_purpose = to_region->is_young() ? GCAllocForSurvived : GCAllocForTenured;
if (g1p->track_object_age(alloc_purpose)) {
// We could simply do obj->incr_age(). However, this causes a
// performance issue. obj->incr_age() will first check whether
// the object has a displaced mark by checking its mark word;
// getting the mark word from the new location of the object
// stalls. So, given that we already have the mark word and we
// are about to install it anyway, it's better to increase the
// age on the mark word, when the object does not have a
// displaced mark word. We're not expecting many objects to have
// a displaced marked word, so that case is not optimized
// further (it could be...) and we simply call obj->incr_age().
if (m->has_displaced_mark_helper()) {
// in this case, we have to install the mark word first,
// otherwise obj looks to be forwarded (the old mark word,
// which contains the forward pointer, was copied)
obj->set_mark(m);
obj->incr_age();
} else {
m = m->incr_age();
obj->set_mark(m);
}
age_table()->add(obj, word_sz);
} else {
obj->set_mark(m);
}
if (G1StringDedup::is_enabled()) {
G1StringDedup::enqueue_from_evacuation(from_region->is_young(),
to_region->is_young(),
queue_num(),
obj);
}
size_t* surv_young_words = surviving_young_words();
surv_young_words[young_index] += word_sz;
if (obj->is_objArray() && arrayOop(obj)->length() >= ParGCArrayScanChunk) {
// We keep track of the next start index in the length field of
// the to-space object. The actual length can be found in the
// length field of the from-space object.
arrayOop(obj)->set_length(0);
oop* old_p = set_partial_array_mask(old);
push_on_queue(old_p);
} else {
// No point in using the slower heap_region_containing() method,
// given that we know obj is in the heap.
_scanner.set_region(_g1h->heap_region_containing_raw(obj));
obj->oop_iterate_backwards(&_scanner);
}
} else {
undo_allocation(alloc_purpose, obj_ptr, word_sz);
obj = forward_ptr;
}
return obj;
}
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
#include "gc_implementation/g1/dirtyCardQueue.hpp"
#include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
#include "gc_implementation/g1/g1CollectedHeap.hpp"
#include "gc_implementation/g1/g1CollectorPolicy.hpp"
#include "gc_implementation/g1/g1OopClosures.hpp"
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/shared/ageTable.hpp"
#include "memory/allocation.hpp"
#include "oops/oop.hpp"
class HeapRegion;
class outputStream;
class G1ParScanThreadState : public StackObj {
protected:
G1CollectedHeap* _g1h;
RefToScanQueue* _refs;
DirtyCardQueue _dcq;
G1SATBCardTableModRefBS* _ct_bs;
G1RemSet* _g1_rem;
G1ParGCAllocBuffer _surviving_alloc_buffer;
G1ParGCAllocBuffer _tenured_alloc_buffer;
G1ParGCAllocBuffer* _alloc_buffers[GCAllocPurposeCount];
ageTable _age_table;
G1ParScanClosure _scanner;
size_t _alloc_buffer_waste;
size_t _undo_waste;
OopsInHeapRegionClosure* _evac_failure_cl;
int _hash_seed;
uint _queue_num;
size_t _term_attempts;
double _start;
double _start_strong_roots;
double _strong_roots_time;
double _start_term;
double _term_time;
// Map from young-age-index (0 == not young, 1 is youngest) to
// surviving words. base is what we get back from the malloc call
size_t* _surviving_young_words_base;
// this points into the array, as we use the first few entries for padding
size_t* _surviving_young_words;
#define PADDING_ELEM_NUM (DEFAULT_CACHE_LINE_SIZE / sizeof(size_t))
void add_to_alloc_buffer_waste(size_t waste) { _alloc_buffer_waste += waste; }
void add_to_undo_waste(size_t waste) { _undo_waste += waste; }
DirtyCardQueue& dirty_card_queue() { return _dcq; }
G1SATBCardTableModRefBS* ctbs() { return _ct_bs; }
template <class T> inline void immediate_rs_update(HeapRegion* from, T* p, int tid);
template <class T> void deferred_rs_update(HeapRegion* from, T* p, int tid) {
// If the new value of the field points to the same region or
// is the to-space, we don't need to include it in the Rset updates.
if (!from->is_in_reserved(oopDesc::load_decode_heap_oop(p)) && !from->is_survivor()) {
size_t card_index = ctbs()->index_for(p);
// If the card hasn't been added to the buffer, do it.
if (ctbs()->mark_card_deferred(card_index)) {
dirty_card_queue().enqueue((jbyte*)ctbs()->byte_for_index(card_index));
}
}
}
public:
G1ParScanThreadState(G1CollectedHeap* g1h, uint queue_num, ReferenceProcessor* rp);
~G1ParScanThreadState() {
retire_alloc_buffers();
FREE_C_HEAP_ARRAY(size_t, _surviving_young_words_base, mtGC);
}
RefToScanQueue* refs() { return _refs; }
ageTable* age_table() { return &_age_table; }
G1ParGCAllocBuffer* alloc_buffer(GCAllocPurpose purpose) {
return _alloc_buffers[purpose];
}
size_t alloc_buffer_waste() const { return _alloc_buffer_waste; }
size_t undo_waste() const { return _undo_waste; }
#ifdef ASSERT
bool verify_ref(narrowOop* ref) const;
bool verify_ref(oop* ref) const;
bool verify_task(StarTask ref) const;
#endif // ASSERT
template <class T> void push_on_queue(T* ref) {
assert(verify_ref(ref), "sanity");
refs()->push(ref);
}
template <class T> inline void update_rs(HeapRegion* from, T* p, int tid);
HeapWord* allocate_slow(GCAllocPurpose purpose, size_t word_sz) {
HeapWord* obj = NULL;
size_t gclab_word_size = _g1h->desired_plab_sz(purpose);
if (word_sz * 100 < gclab_word_size * ParallelGCBufferWastePct) {
G1ParGCAllocBuffer* alloc_buf = alloc_buffer(purpose);
add_to_alloc_buffer_waste(alloc_buf->words_remaining());
alloc_buf->retire(false /* end_of_gc */, false /* retain */);
HeapWord* buf = _g1h->par_allocate_during_gc(purpose, gclab_word_size);
if (buf == NULL) return NULL; // Let caller handle allocation failure.
// Otherwise.
alloc_buf->set_word_size(gclab_word_size);
alloc_buf->set_buf(buf);
obj = alloc_buf->allocate(word_sz);
assert(obj != NULL, "buffer was definitely big enough...");
} else {
obj = _g1h->par_allocate_during_gc(purpose, word_sz);
}
return obj;
}
HeapWord* allocate(GCAllocPurpose purpose, size_t word_sz) {
HeapWord* obj = alloc_buffer(purpose)->allocate(word_sz);
if (obj != NULL) return obj;
return allocate_slow(purpose, word_sz);
}
void undo_allocation(GCAllocPurpose purpose, HeapWord* obj, size_t word_sz) {
if (alloc_buffer(purpose)->contains(obj)) {
assert(alloc_buffer(purpose)->contains(obj + word_sz - 1),
"should contain whole object");
alloc_buffer(purpose)->undo_allocation(obj, word_sz);
} else {
CollectedHeap::fill_with_object(obj, word_sz);
add_to_undo_waste(word_sz);
}
}
void set_evac_failure_closure(OopsInHeapRegionClosure* evac_failure_cl) {
_evac_failure_cl = evac_failure_cl;
}
OopsInHeapRegionClosure* evac_failure_closure() {
return _evac_failure_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++; }
void start_strong_roots() {
_start_strong_roots = os::elapsedTime();
}
void end_strong_roots() {
_strong_roots_time += (os::elapsedTime() - _start_strong_roots);
}
double strong_roots_time() const { return _strong_roots_time; }
void start_term_time() {
note_term_attempt();
_start_term = os::elapsedTime();
}
void end_term_time() {
_term_time += (os::elapsedTime() - _start_term);
}
double term_time() const { return _term_time; }
double elapsed_time() const {
return os::elapsedTime() - _start;
}
static void
print_termination_stats_hdr(outputStream* const st = gclog_or_tty);
void
print_termination_stats(int i, outputStream* const st = gclog_or_tty) const;
size_t* surviving_young_words() {
// We add on to hide entry 0 which accumulates surviving words for
// age -1 regions (i.e. non-young ones)
return _surviving_young_words;
}
private:
void retire_alloc_buffers() {
for (int ap = 0; ap < GCAllocPurposeCount; ++ap) {
size_t waste = _alloc_buffers[ap]->words_remaining();
add_to_alloc_buffer_waste(waste);
_alloc_buffers[ap]->flush_stats_and_retire(_g1h->stats_for_purpose((GCAllocPurpose)ap),
true /* end_of_gc */,
false /* retain */);
}
}
#define G1_PARTIAL_ARRAY_MASK 0x2
inline bool has_partial_array_mask(oop* 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* 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) const {
assert(((uintptr_t)(void *)obj & G1_PARTIAL_ARRAY_MASK) == 0, "Information loss!");
return (oop*) ((uintptr_t)(void *)obj | G1_PARTIAL_ARRAY_MASK);
}
inline oop clear_partial_array_mask(oop* ref) const {
return cast_to_oop((intptr_t)ref & ~G1_PARTIAL_ARRAY_MASK);
}
inline void do_oop_partial_array(oop* p);
// 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 const obj);
template <class T> inline void deal_with_reference(T* ref_to_scan);
inline void deal_with_reference(StarTask ref);
public:
void trim_queue();
};
#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_HPP
/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP
#include "gc_implementation/g1/g1ParScanThreadState.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "oops/oop.inline.hpp"
template <class T> inline void G1ParScanThreadState::immediate_rs_update(HeapRegion* from, T* p, int tid) {
if (!from->is_survivor()) {
_g1_rem->par_write_ref(from, p, tid);
}
}
template <class T> void G1ParScanThreadState::update_rs(HeapRegion* from, T* p, int tid) {
if (G1DeferredRSUpdate) {
deferred_rs_update(from, p, tid);
} else {
immediate_rs_update(from, p, tid);
}
}
inline void G1ParScanThreadState::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;
int remainder = end - start;
// We'll try not to push a range that's smaller than ParGCArrayScanChunk.
if (remainder > 2 * ParGCArrayScanChunk) {
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);
}
template <class T> inline void G1ParScanThreadState::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 {
do_oop_partial_array((oop*)ref_to_scan);
}
}
inline void G1ParScanThreadState::deal_with_reference(StarTask ref) {
assert(verify_task(ref), "sanity");
if (ref.is_narrow()) {
deal_with_reference((narrowOop*)ref);
} else {
deal_with_reference((oop*)ref);
}
}
#endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP */
......@@ -26,6 +26,7 @@
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_INLINE_HPP
#include "gc_implementation/g1/g1RemSet.hpp"
#include "gc_implementation/g1/heapRegion.hpp"
#include "gc_implementation/g1/heapRegionRemSet.hpp"
#include "oops/oop.inline.hpp"
......
Markdown is supported
0% .
You are about to add 0 people to the discussion. Proceed with caution.
先完成此消息的编辑!
想要评论请 注册