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/*
* Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP
#define SHARE_VM_GC_IMPLEMENTATION_G1_G1PARSCANTHREADSTATE_INLINE_HPP
#include "gc_implementation/g1/g1ParScanThreadState.hpp"
#include "gc_implementation/g1/g1RemSet.inline.hpp"
#include "oops/oop.inline.hpp"
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.
const InCSetState in_cset_state = _g1h->in_cset_state(obj);
if (in_cset_state.is_in_cset()) {
oop forwardee;
markOop m = obj->mark();
if (m->is_marked()) {
forwardee = (oop) m->decode_pointer();
} else {
forwardee = copy_to_survivor_space(in_cset_state, obj, m);
}
oopDesc::encode_store_heap_oop(p, forwardee);
} else if (in_cset_state.is_humongous()) {
_g1h->set_humongous_is_live(obj);
} else {
assert(!in_cset_state.is_in_cset_or_humongous(),
err_msg("In_cset_state must be NotInCSet here, but is " CSETSTATE_FORMAT, in_cset_state.value()));
}
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 */
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