src/share/vm/gc_implementation/g1/g1ParScanThreadState.inline.hpp

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rev 6626 : imported patch 8035400-move-g1parscanthreadstate-into-own-files
rev 6627 : imported patch 8035400-2-bengt-fixes
rev 6628 : imported patch 8035401-fix-visibility-of-g1parscanthreadstate
rev 6630 : imported patch 8035401-2-another-inline-try

*** 41,46 **** --- 41,153 ---- } else { immediate_rs_update(from, p, tid); } } + template <class T> void G1ParScanThreadState::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()); + } + + 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::dispatch_reference(StarTask ref) { + assert(verify_task(ref), "sanity"); + if (ref.is_narrow()) { + deal_with_reference((narrowOop*)ref); + } else { + deal_with_reference((oop*)ref); + } + } + + void G1ParScanThreadState::steal_and_trim_queue(RefToScanQueueSet *task_queues) { + StarTask stolen_task; + while (task_queues->steal(queue_num(), hash_seed(), stolen_task)) { + assert(verify_task(stolen_task), "sanity"); + dispatch_reference(stolen_task); + + // We've just processed a reference and we might have made + // available new entries on the queues. So we have to make sure + // we drain the queues as necessary. + trim_queue(); + } + } + #endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP */