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6784849: par compact - can fail when to_space is non-empty

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Reviewed-by: jmasa, tonyp
This commit is contained in:
John Coomes 2008-12-18 10:53:35 -08:00
parent a88e734cac
commit f90394b6fb
2 changed files with 47 additions and 32 deletions
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64
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.cpp
View File

@ -726,7 +726,7 @@ HeapWord* ParallelCompactData::calc_new_pointer(HeapWord* addr) {
size_t live_to_left = bitmap->live_words_in_range(search_start, oop(addr));
result += partial_obj_size + live_to_left;
assert(result <= addr, "object cannot move to the right");
DEBUG_ONLY(PSParallelCompact::check_new_location(addr, result);)
return result;
}
@ -1828,14 +1828,6 @@ void PSParallelCompact::summary_phase(ParCompactionManager* cm,
new_top_addr);
assert(done, "space must fit into old gen");
// XXX - this is necessary because decrement_destination_counts() tests
// source_region() to determine if a region will be filled. Probably
// better to pass src_space->new_top() into decrement_destination_counts
// and test that instead.
//
// Clear the source_region field for each region in the space.
clear_source_region(space->bottom(), _space_info[id].new_top());
// Reset the new_top value for the space.
_space_info[id].set_new_top(space->bottom());
} else if (live > 0) {
@ -1854,7 +1846,6 @@ void PSParallelCompact::summary_phase(ParCompactionManager* cm,
dst_space_id = SpaceId(id);
dst_space_end = space->end();
new_top_addr = _space_info[id].new_top_addr();
HeapWord* const clear_end = _space_info[id].new_top();
NOT_PRODUCT(summary_phase_msg(dst_space_id,
space->bottom(), dst_space_end,
SpaceId(id), next_src_addr, space->top());)
@ -1865,13 +1856,6 @@ void PSParallelCompact::summary_phase(ParCompactionManager* cm,
new_top_addr);
assert(done, "space must fit when compacted into itself");
assert(*new_top_addr <= space->top(), "usage should not grow");
// XXX - this should go away. See comments above.
//
// Clear the source_region field in regions at the end of the space that
// will not be filled.
HeapWord* const clear_beg = _summary_data.region_align_up(*new_top_addr);
clear_source_region(clear_beg, clear_end);
}
}
@ -3051,19 +3035,34 @@ HeapWord* PSParallelCompact::first_src_addr(HeapWord* const dest_addr,
}
void PSParallelCompact::decrement_destination_counts(ParCompactionManager* cm,
SpaceId src_space_id,
size_t beg_region,
HeapWord* end_addr)
{
ParallelCompactData& sd = summary_data();
#ifdef ASSERT
MutableSpace* const src_space = _space_info[src_space_id].space();
HeapWord* const beg_addr = sd.region_to_addr(beg_region);
assert(src_space->contains(beg_addr) || beg_addr == src_space->end(),
"src_space_id does not match beg_addr");
assert(src_space->contains(end_addr) || end_addr == src_space->end(),
"src_space_id does not match end_addr");
#endif // #ifdef ASSERT
RegionData* const beg = sd.region(beg_region);
HeapWord* const end_addr_aligned_up = sd.region_align_up(end_addr);
RegionData* const end = sd.addr_to_region_ptr(end_addr_aligned_up);
size_t cur_idx = beg_region;
for (RegionData* cur = beg; cur < end; ++cur, ++cur_idx) {
RegionData* const end = sd.addr_to_region_ptr(sd.region_align_up(end_addr));
// Regions up to new_top() are enqueued if they become available.
HeapWord* const new_top = _space_info[src_space_id].new_top();
RegionData* const enqueue_end =
sd.addr_to_region_ptr(sd.region_align_up(new_top));
for (RegionData* cur = beg; cur < end; ++cur) {
assert(cur->data_size() > 0, "region must have live data");
cur->decrement_destination_count();
if (cur_idx <= cur->source_region() && cur->available() && cur->claim()) {
cm->save_for_processing(cur_idx);
if (cur < enqueue_end && cur->available() && cur->claim()) {
cm->save_for_processing(sd.region(cur));
}
}
}
@ -3178,7 +3177,8 @@ void PSParallelCompact::fill_region(ParCompactionManager* cm, size_t region_idx)
HeapWord* const old_src_addr = closure.source();
closure.copy_partial_obj();
if (closure.is_full()) {
decrement_destination_counts(cm, src_region_idx, closure.source());
decrement_destination_counts(cm, src_space_id, src_region_idx,
closure.source());
region_ptr->set_deferred_obj_addr(NULL);
region_ptr->set_completed();
return;
@ -3187,7 +3187,7 @@ void PSParallelCompact::fill_region(ParCompactionManager* cm, size_t region_idx)
HeapWord* const end_addr = sd.region_align_down(closure.source());
if (sd.region_align_down(old_src_addr) != end_addr) {
// The partial object was copied from more than one source region.
decrement_destination_counts(cm, src_region_idx, end_addr);
decrement_destination_counts(cm, src_space_id, src_region_idx, end_addr);
// Move to the next source region, possibly switching spaces as well. All
// args except end_addr may be modified.
@ -3227,19 +3227,21 @@ void PSParallelCompact::fill_region(ParCompactionManager* cm, size_t region_idx)
region_ptr->set_deferred_obj_addr(closure.destination());
status = closure.copy_until_full(); // copies from closure.source()
decrement_destination_counts(cm, src_region_idx, closure.source());
decrement_destination_counts(cm, src_space_id, src_region_idx,
closure.source());
region_ptr->set_completed();
return;
}
if (status == ParMarkBitMap::full) {
decrement_destination_counts(cm, src_region_idx, closure.source());
decrement_destination_counts(cm, src_space_id, src_region_idx,
closure.source());
region_ptr->set_deferred_obj_addr(NULL);
region_ptr->set_completed();
return;
}
decrement_destination_counts(cm, src_region_idx, end_addr);
decrement_destination_counts(cm, src_space_id, src_region_idx, end_addr);
// Move to the next source region, possibly switching spaces as well. All
// args except end_addr may be modified.
@ -3318,7 +3320,7 @@ void PSParallelCompact::reset_millis_since_last_gc() {
ParMarkBitMap::IterationStatus MoveAndUpdateClosure::copy_until_full()
{
if (source() != destination()) {
assert(source() > destination(), "must copy to the left");
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
Copy::aligned_conjoint_words(source(), destination(), words_remaining());
}
update_state(words_remaining());
@ -3339,7 +3341,7 @@ void MoveAndUpdateClosure::copy_partial_obj()
// This test is necessary; if omitted, the pointer updates to a partial object
// that crosses the dense prefix boundary could be overwritten.
if (source() != destination()) {
assert(source() > destination(), "must copy to the left");
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
Copy::aligned_conjoint_words(source(), destination(), words);
}
update_state(words);
@ -3364,7 +3366,7 @@ MoveAndUpdateClosure::do_addr(HeapWord* addr, size_t words) {
}
if (destination() != source()) {
assert(destination() < source(), "must copy to the left");
DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
Copy::aligned_conjoint_words(source(), destination(), words);
}

15
hotspot/src/share/vm/gc_implementation/parallelScavenge/psParallelCompact.hpp
View File

@ -1154,8 +1154,10 @@ class PSParallelCompact : AllStatic {
HeapWord* end_addr);
// Decrement the destination count for each non-empty source region in the
// range [beg_region, region(region_align_up(end_addr))).
// range [beg_region, region(region_align_up(end_addr))). If the destination
// count for a region goes to 0 and it needs to be filled, enqueue it.
static void decrement_destination_counts(ParCompactionManager* cm,
SpaceId src_space_id,
size_t beg_region,
HeapWord* end_addr);
@ -1230,6 +1232,8 @@ class PSParallelCompact : AllStatic {
#endif // #ifndef PRODUCT
#ifdef ASSERT
// Sanity check the new location of a word in the heap.
static inline void check_new_location(HeapWord* old_addr, HeapWord* new_addr);
// Verify that all the regions have been emptied.
static void verify_complete(SpaceId space_id);
#endif // #ifdef ASSERT
@ -1397,6 +1401,15 @@ inline void PSParallelCompact::adjust_pointer(T* p,
}
}
#ifdef ASSERT
inline void
PSParallelCompact::check_new_location(HeapWord* old_addr, HeapWord* new_addr)
{
assert(old_addr >= new_addr || space_id(old_addr) != space_id(new_addr),
"must move left or to a different space");
}
#endif // ASSERT
class MoveAndUpdateClosure: public ParMarkBitMapClosure {
public:
inline MoveAndUpdateClosure(ParMarkBitMap* bitmap, ParCompactionManager* cm,