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6578152: fill_region_with_object has usability and safety issues

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Reviewed-by: apetrusenko, ysr
This commit is contained in:
John Coomes 2008-12-11 12:05:08 -08:00
parent 26f6b1692a
commit 000b184507
25 changed files with 261 additions and 198 deletions
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23
hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweep.cpp
View file

@ -389,7 +389,7 @@ bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
// full GC.
const size_t alignment = old_gen->virtual_space()->alignment();
const size_t eden_used = eden_space->used_in_bytes();
const size_t promoted = (size_t)(size_policy->avg_promoted()->padded_average());
const size_t promoted = (size_t)size_policy->avg_promoted()->padded_average();
const size_t absorb_size = align_size_up(eden_used + promoted, alignment);
const size_t eden_capacity = eden_space->capacity_in_bytes();
@ -416,16 +416,14 @@ bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
// Fill the unused part of the old gen.
MutableSpace* const old_space = old_gen->object_space();
MemRegion old_gen_unused(old_space->top(), old_space->end());
HeapWord* const unused_start = old_space->top();
size_t const unused_words = pointer_delta(old_space->end(), unused_start);
// If the unused part of the old gen cannot be filled, skip
// absorbing eden.
if (old_gen_unused.word_size() < SharedHeap::min_fill_size()) {
return false;
}
if (!old_gen_unused.is_empty()) {
SharedHeap::fill_region_with_object(old_gen_unused);
if (unused_words > 0) {
if (unused_words < CollectedHeap::min_fill_size()) {
return false; // If the old gen cannot be filled, must give up.
}
CollectedHeap::fill_with_objects(unused_start, unused_words);
}
// Take the live data from eden and set both top and end in the old gen to
@ -441,9 +439,8 @@ bool PSMarkSweep::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_policy,
// Update the object start array for the filler object and the data from eden.
ObjectStartArray* const start_array = old_gen->start_array();
HeapWord* const start = old_gen_unused.start();
for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) {
start_array->allocate_block(addr);
for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) {
start_array->allocate_block(p);
}
// Could update the promoted average here, but it is not typically updated at

19
hotspot/src/share/vm/gc_implementation/parallelScavenge/psMarkSweepDecorator.cpp
View file

@ -275,22 +275,9 @@ bool PSMarkSweepDecorator::insert_deadspace(size_t& allowed_deadspace_words,
HeapWord* q, size_t deadlength) {
if (allowed_deadspace_words >= deadlength) {
allowed_deadspace_words -= deadlength;
oop(q)->set_mark(markOopDesc::prototype()->set_marked());
const size_t aligned_min_int_array_size =
align_object_size(typeArrayOopDesc::header_size(T_INT));
if (deadlength >= aligned_min_int_array_size) {
oop(q)->set_klass(Universe::intArrayKlassObj());
assert(((deadlength - aligned_min_int_array_size) * (HeapWordSize/sizeof(jint))) < (size_t)max_jint,
"deadspace too big for Arrayoop");
typeArrayOop(q)->set_length((int)((deadlength - aligned_min_int_array_size)
* (HeapWordSize/sizeof(jint))));
} else {
assert((int) deadlength == instanceOopDesc::header_size(),
"size for smallest fake dead object doesn't match");
oop(q)->set_klass(SystemDictionary::object_klass());
}
assert((int) deadlength == oop(q)->size(),
"make sure size for fake dead object match");
CollectedHeap::fill_with_object(q, deadlength);
oop(q)->set_mark(oop(q)->mark()->set_marked());
assert((int) deadlength == oop(q)->size(), "bad filler object size");
// Recall that we required "q == compaction_top".
return true;
} else {

19
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
View file

@ -1308,8 +1308,7 @@ void PSParallelCompact::fill_dense_prefix_end(SpaceId id)
}
#endif // #ifdef _LP64
MemRegion region(obj_beg, obj_len);
SharedHeap::fill_region_with_object(region);
gc_heap()->fill_with_object(obj_beg, obj_len);
_mark_bitmap.mark_obj(obj_beg, obj_len);
_summary_data.add_obj(obj_beg, obj_len);
assert(start_array(id) != NULL, "sanity");
@ -1807,9 +1806,14 @@ bool PSParallelCompact::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_po
// Fill the unused part of the old gen.
MutableSpace* const old_space = old_gen->object_space();
MemRegion old_gen_unused(old_space->top(), old_space->end());
if (!old_gen_unused.is_empty()) {
SharedHeap::fill_region_with_object(old_gen_unused);
HeapWord* const unused_start = old_space->top();
size_t const unused_words = pointer_delta(old_space->end(), unused_start);
if (unused_words > 0) {
if (unused_words < CollectedHeap::min_fill_size()) {
return false; // If the old gen cannot be filled, must give up.
}
CollectedHeap::fill_with_objects(unused_start, unused_words);
}
// Take the live data from eden and set both top and end in the old gen to
@ -1825,9 +1829,8 @@ bool PSParallelCompact::absorb_live_data_from_eden(PSAdaptiveSizePolicy* size_po
// Update the object start array for the filler object and the data from eden.
ObjectStartArray* const start_array = old_gen->start_array();
HeapWord* const start = old_gen_unused.start();
for (HeapWord* addr = start; addr < new_top; addr += oop(addr)->size()) {
start_array->allocate_block(addr);
for (HeapWord* p = unused_start; p < new_top; p += oop(p)->size()) {
start_array->allocate_block(p);
}
// Could update the promoted average here, but it is not typically updated at

31
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp
View file

@ -1324,31 +1324,28 @@ inline void UpdateOnlyClosure::do_addr(HeapWord* addr)
oop(addr)->update_contents(compaction_manager());
}
class FillClosure: public ParMarkBitMapClosure {
public:
class FillClosure: public ParMarkBitMapClosure
{
public:
FillClosure(ParCompactionManager* cm, PSParallelCompact::SpaceId space_id) :
ParMarkBitMapClosure(PSParallelCompact::mark_bitmap(), cm),
_space_id(space_id),
_start_array(PSParallelCompact::start_array(space_id)) {
assert(_space_id == PSParallelCompact::perm_space_id ||
_space_id == PSParallelCompact::old_space_id,
_start_array(PSParallelCompact::start_array(space_id))
{
assert(space_id == PSParallelCompact::perm_space_id ||
space_id == PSParallelCompact::old_space_id,
"cannot use FillClosure in the young gen");
assert(bitmap() != NULL, "need a bitmap");
assert(_start_array != NULL, "need a start array");
}
void fill_region(HeapWord* addr, size_t size) {
MemRegion region(addr, size);
SharedHeap::fill_region_with_object(region);
_start_array->allocate_block(addr);
}
virtual IterationStatus do_addr(HeapWord* addr, size_t size) {
fill_region(addr, size);
CollectedHeap::fill_with_objects(addr, size);
HeapWord* const end = addr + size;
do {
_start_array->allocate_block(addr);
addr += oop(addr)->size();
} while (addr < end);
return ParMarkBitMap::incomplete;
}
private:
const PSParallelCompact::SpaceId _space_id;
ObjectStartArray* const _start_array;
ObjectStartArray* const _start_array;
};

23
hotspot/src/share/vm/gc_implementation/parallelScavenge/psPromotionManager.cpp
View file

@ -499,26 +499,15 @@ oop PSPromotionManager::copy_to_survivor_space(oop o, bool depth_first) {
// We lost, someone else "owns" this object
guarantee(o->is_forwarded(), "Object must be forwarded if the cas failed.");
// Unallocate the space used. NOTE! We may have directly allocated
// the object. If so, we cannot deallocate it, so we have to test!
// Try to deallocate the space. If it was directly allocated we cannot
// deallocate it, so we have to test. If the deallocation fails,
// overwrite with a filler object.
if (new_obj_is_tenured) {
if (!_old_lab.unallocate_object(new_obj)) {
// The promotion lab failed to unallocate the object.
// We need to overwrite the object with a filler that
// contains no interior pointers.
MemRegion mr((HeapWord*)new_obj, new_obj_size);
// Clean this up and move to oopFactory (see bug 4718422)
SharedHeap::fill_region_with_object(mr);
}
} else {
if (!_young_lab.unallocate_object(new_obj)) {
// The promotion lab failed to unallocate the object.
// We need to overwrite the object with a filler that
// contains no interior pointers.
MemRegion mr((HeapWord*)new_obj, new_obj_size);
// Clean this up and move to oopFactory (see bug 4718422)
SharedHeap::fill_region_with_object(mr);
CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
}
} else if (!_young_lab.unallocate_object(new_obj)) {
CollectedHeap::fill_with_object((HeapWord*) new_obj, new_obj_size);
}
// don't update this before the unallocation!