Mon, 08 Dec 2014 18:57:33 +0100
8067655: Clean up G1 remembered set oop iteration
Summary: Pass on the static type G1ParPushHeapRSClosure to allow oop_iterate devirtualization
Reviewed-by: jmasa, kbarrett
tschatzl@6937 | 1 | /* |
tschatzl@6937 | 2 | * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
tschatzl@6937 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
tschatzl@6937 | 4 | * |
tschatzl@6937 | 5 | * This code is free software; you can redistribute it and/or modify it |
tschatzl@6937 | 6 | * under the terms of the GNU General Public License version 2 only, as |
tschatzl@6937 | 7 | * published by the Free Software Foundation. |
tschatzl@6937 | 8 | * |
tschatzl@6937 | 9 | * This code is distributed in the hope that it will be useful, but WITHOUT |
tschatzl@6937 | 10 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
tschatzl@6937 | 11 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
tschatzl@6937 | 12 | * version 2 for more details (a copy is included in the LICENSE file that |
tschatzl@6937 | 13 | * accompanied this code). |
tschatzl@6937 | 14 | * |
tschatzl@6937 | 15 | * You should have received a copy of the GNU General Public License version |
tschatzl@6937 | 16 | * 2 along with this work; if not, write to the Free Software Foundation, |
tschatzl@6937 | 17 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
tschatzl@6937 | 18 | * |
tschatzl@6937 | 19 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
tschatzl@6937 | 20 | * or visit www.oracle.com if you need additional information or have any |
tschatzl@6937 | 21 | * questions. |
tschatzl@6937 | 22 | * |
tschatzl@6937 | 23 | */ |
tschatzl@6937 | 24 | |
tschatzl@6937 | 25 | #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP |
tschatzl@6937 | 26 | #define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP |
tschatzl@6937 | 27 | |
tschatzl@6937 | 28 | #include "gc_implementation/g1/g1ParScanThreadState.hpp" |
tschatzl@6937 | 29 | #include "gc_implementation/g1/g1RemSet.inline.hpp" |
tschatzl@6937 | 30 | #include "oops/oop.inline.hpp" |
tschatzl@6937 | 31 | |
tschatzl@6938 | 32 | template <class T> void G1ParScanThreadState::do_oop_evac(T* p, HeapRegion* from) { |
tschatzl@6938 | 33 | assert(!oopDesc::is_null(oopDesc::load_decode_heap_oop(p)), |
tschatzl@6938 | 34 | "Reference should not be NULL here as such are never pushed to the task queue."); |
tschatzl@6938 | 35 | oop obj = oopDesc::load_decode_heap_oop_not_null(p); |
tschatzl@6938 | 36 | |
tschatzl@6938 | 37 | // Although we never intentionally push references outside of the collection |
tschatzl@6938 | 38 | // set, due to (benign) races in the claim mechanism during RSet scanning more |
tschatzl@6938 | 39 | // than one thread might claim the same card. So the same card may be |
tschatzl@6938 | 40 | // processed multiple times. So redo this check. |
tschatzl@7010 | 41 | G1CollectedHeap::in_cset_state_t in_cset_state = _g1h->in_cset_state(obj); |
tschatzl@7010 | 42 | if (in_cset_state == G1CollectedHeap::InCSet) { |
tschatzl@6938 | 43 | oop forwardee; |
tschatzl@6938 | 44 | if (obj->is_forwarded()) { |
tschatzl@6938 | 45 | forwardee = obj->forwardee(); |
tschatzl@6938 | 46 | } else { |
tschatzl@6938 | 47 | forwardee = copy_to_survivor_space(obj); |
tschatzl@6938 | 48 | } |
tschatzl@6938 | 49 | oopDesc::encode_store_heap_oop(p, forwardee); |
tschatzl@7010 | 50 | } else if (in_cset_state == G1CollectedHeap::IsHumongous) { |
tschatzl@7010 | 51 | _g1h->set_humongous_is_live(obj); |
tschatzl@7010 | 52 | } else { |
tschatzl@7010 | 53 | assert(in_cset_state == G1CollectedHeap::InNeither, |
tschatzl@7010 | 54 | err_msg("In_cset_state must be InNeither here, but is %d", in_cset_state)); |
tschatzl@6938 | 55 | } |
tschatzl@6938 | 56 | |
tschatzl@6938 | 57 | assert(obj != NULL, "Must be"); |
tschatzl@6938 | 58 | update_rs(from, p, queue_num()); |
tschatzl@6938 | 59 | } |
tschatzl@6938 | 60 | |
tschatzl@6937 | 61 | inline void G1ParScanThreadState::do_oop_partial_array(oop* p) { |
tschatzl@6937 | 62 | assert(has_partial_array_mask(p), "invariant"); |
tschatzl@6937 | 63 | oop from_obj = clear_partial_array_mask(p); |
tschatzl@6937 | 64 | |
tschatzl@6937 | 65 | assert(Universe::heap()->is_in_reserved(from_obj), "must be in heap."); |
tschatzl@6937 | 66 | assert(from_obj->is_objArray(), "must be obj array"); |
tschatzl@6937 | 67 | objArrayOop from_obj_array = objArrayOop(from_obj); |
tschatzl@6937 | 68 | // The from-space object contains the real length. |
tschatzl@6937 | 69 | int length = from_obj_array->length(); |
tschatzl@6937 | 70 | |
tschatzl@6937 | 71 | assert(from_obj->is_forwarded(), "must be forwarded"); |
tschatzl@6937 | 72 | oop to_obj = from_obj->forwardee(); |
tschatzl@6937 | 73 | assert(from_obj != to_obj, "should not be chunking self-forwarded objects"); |
tschatzl@6937 | 74 | objArrayOop to_obj_array = objArrayOop(to_obj); |
tschatzl@6937 | 75 | // We keep track of the next start index in the length field of the |
tschatzl@6937 | 76 | // to-space object. |
tschatzl@6937 | 77 | int next_index = to_obj_array->length(); |
tschatzl@6937 | 78 | assert(0 <= next_index && next_index < length, |
tschatzl@6937 | 79 | err_msg("invariant, next index: %d, length: %d", next_index, length)); |
tschatzl@6937 | 80 | |
tschatzl@6937 | 81 | int start = next_index; |
tschatzl@6937 | 82 | int end = length; |
tschatzl@6937 | 83 | int remainder = end - start; |
tschatzl@6937 | 84 | // We'll try not to push a range that's smaller than ParGCArrayScanChunk. |
tschatzl@6937 | 85 | if (remainder > 2 * ParGCArrayScanChunk) { |
tschatzl@6937 | 86 | end = start + ParGCArrayScanChunk; |
tschatzl@6937 | 87 | to_obj_array->set_length(end); |
tschatzl@6937 | 88 | // Push the remainder before we process the range in case another |
tschatzl@6937 | 89 | // worker has run out of things to do and can steal it. |
tschatzl@6937 | 90 | oop* from_obj_p = set_partial_array_mask(from_obj); |
tschatzl@6937 | 91 | push_on_queue(from_obj_p); |
tschatzl@6937 | 92 | } else { |
tschatzl@6937 | 93 | assert(length == end, "sanity"); |
tschatzl@6937 | 94 | // We'll process the final range for this object. Restore the length |
tschatzl@6937 | 95 | // so that the heap remains parsable in case of evacuation failure. |
tschatzl@6937 | 96 | to_obj_array->set_length(end); |
tschatzl@6937 | 97 | } |
tschatzl@6937 | 98 | _scanner.set_region(_g1h->heap_region_containing_raw(to_obj)); |
tschatzl@6937 | 99 | // Process indexes [start,end). It will also process the header |
tschatzl@6937 | 100 | // along with the first chunk (i.e., the chunk with start == 0). |
tschatzl@6937 | 101 | // Note that at this point the length field of to_obj_array is not |
tschatzl@6937 | 102 | // correct given that we are using it to keep track of the next |
tschatzl@6937 | 103 | // start index. oop_iterate_range() (thankfully!) ignores the length |
tschatzl@6937 | 104 | // field and only relies on the start / end parameters. It does |
tschatzl@6937 | 105 | // however return the size of the object which will be incorrect. So |
tschatzl@6937 | 106 | // we have to ignore it even if we wanted to use it. |
tschatzl@6937 | 107 | to_obj_array->oop_iterate_range(&_scanner, start, end); |
tschatzl@6937 | 108 | } |
tschatzl@6937 | 109 | |
tschatzl@6937 | 110 | template <class T> inline void G1ParScanThreadState::deal_with_reference(T* ref_to_scan) { |
tschatzl@6937 | 111 | if (!has_partial_array_mask(ref_to_scan)) { |
tschatzl@6937 | 112 | // Note: we can use "raw" versions of "region_containing" because |
tschatzl@6937 | 113 | // "obj_to_scan" is definitely in the heap, and is not in a |
tschatzl@6937 | 114 | // humongous region. |
tschatzl@6937 | 115 | HeapRegion* r = _g1h->heap_region_containing_raw(ref_to_scan); |
tschatzl@6937 | 116 | do_oop_evac(ref_to_scan, r); |
tschatzl@6937 | 117 | } else { |
tschatzl@6937 | 118 | do_oop_partial_array((oop*)ref_to_scan); |
tschatzl@6937 | 119 | } |
tschatzl@6937 | 120 | } |
tschatzl@6937 | 121 | |
tschatzl@6938 | 122 | inline void G1ParScanThreadState::dispatch_reference(StarTask ref) { |
tschatzl@6937 | 123 | assert(verify_task(ref), "sanity"); |
tschatzl@6937 | 124 | if (ref.is_narrow()) { |
tschatzl@6937 | 125 | deal_with_reference((narrowOop*)ref); |
tschatzl@6937 | 126 | } else { |
tschatzl@6937 | 127 | deal_with_reference((oop*)ref); |
tschatzl@6937 | 128 | } |
tschatzl@6937 | 129 | } |
tschatzl@6937 | 130 | |
tschatzl@6938 | 131 | void G1ParScanThreadState::steal_and_trim_queue(RefToScanQueueSet *task_queues) { |
tschatzl@6938 | 132 | StarTask stolen_task; |
tschatzl@6938 | 133 | while (task_queues->steal(queue_num(), hash_seed(), stolen_task)) { |
tschatzl@6938 | 134 | assert(verify_task(stolen_task), "sanity"); |
tschatzl@6938 | 135 | dispatch_reference(stolen_task); |
tschatzl@6938 | 136 | |
tschatzl@6938 | 137 | // We've just processed a reference and we might have made |
tschatzl@6938 | 138 | // available new entries on the queues. So we have to make sure |
tschatzl@6938 | 139 | // we drain the queues as necessary. |
tschatzl@6938 | 140 | trim_queue(); |
tschatzl@6938 | 141 | } |
tschatzl@6938 | 142 | } |
tschatzl@6938 | 143 | |
tschatzl@6937 | 144 | #endif /* SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP */ |
tschatzl@6937 | 145 |