6684579: SoftReference processing can be made more efficient
Summary: For current soft-ref clearing policies, we can decide at marking time if a soft-reference will definitely not be cleared, postponing the decision of whether it will definitely be cleared to the final reference processing phase. This can be especially beneficial in the case of concurrent collectors where the marking is usually concurrent but reference processing is usually not.
Reviewed-by: jmasa
/*
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// Inline functions for G1CollectedHeap
inline HeapRegion*
G1CollectedHeap::heap_region_containing(const void* addr) const {
HeapRegion* hr = _hrs->addr_to_region(addr);
// hr can be null if addr in perm_gen
if (hr != NULL && hr->continuesHumongous()) {
hr = hr->humongous_start_region();
}
return hr;
}
inline HeapRegion*
G1CollectedHeap::heap_region_containing_raw(const void* addr) const {
HeapRegion* res = _hrs->addr_to_region(addr);
assert(res != NULL, "addr outside of heap?");
return res;
}
inline bool G1CollectedHeap::obj_in_cs(oop obj) {
HeapRegion* r = _hrs->addr_to_region(obj);
return r != NULL && r->in_collection_set();
}
inline HeapWord* G1CollectedHeap::attempt_allocation(size_t word_size,
bool permit_collection_pause) {
HeapWord* res = NULL;
assert( SafepointSynchronize::is_at_safepoint() ||
Heap_lock->owned_by_self(), "pre-condition of the call" );
if (_cur_alloc_region != NULL) {
// If this allocation causes a region to become non empty,
// then we need to update our free_regions count.
if (_cur_alloc_region->is_empty()) {
res = _cur_alloc_region->allocate(word_size);
if (res != NULL)
_free_regions--;
} else {
res = _cur_alloc_region->allocate(word_size);
}
}
if (res != NULL) {
if (!SafepointSynchronize::is_at_safepoint()) {
assert( Heap_lock->owned_by_self(), "invariant" );
Heap_lock->unlock();
}
return res;
}
// attempt_allocation_slow will also unlock the heap lock when appropriate.
return attempt_allocation_slow(word_size, permit_collection_pause);
}
inline RefToScanQueue* G1CollectedHeap::task_queue(int i) {
return _task_queues->queue(i);
}
inline bool G1CollectedHeap::isMarkedPrev(oop obj) const {
return _cm->prevMarkBitMap()->isMarked((HeapWord *)obj);
}
inline bool G1CollectedHeap::isMarkedNext(oop obj) const {
return _cm->nextMarkBitMap()->isMarked((HeapWord *)obj);
}