86 lines
3.3 KiB
C++
86 lines
3.3 KiB
C++
|
/*
|
||
|
|
* Copyright (c) 2019, 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.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include "precompiled.hpp"
|
||
|
|
#include "gc/z/zObjArrayAllocator.hpp"
|
||
|
|
#include "gc/z/zUtils.inline.hpp"
|
||
|
|
#include "memory/universe.hpp"
|
||
|
|
#include "oops/arrayKlass.hpp"
|
||
|
|
#include "runtime/interfaceSupport.inline.hpp"
|
||
|
|
#include "runtime/handles.hpp"
|
||
|
|
#include "runtime/os.hpp"
|
||
|
|
#include "utilities/debug.hpp"
|
||
|
|
#include "utilities/globalDefinitions.hpp"
|
||
|
|
|
||
|
|
// To avoid delaying safepoints, clearing of arrays is split up in segments
|
||
|
|
// with safepoint polling inbetween. However, we can't have a not-yet-cleared
|
||
|
|
// array of oops on the heap when we safepoint since the GC will then stumble
|
||
|
|
// across uninitialized oops. To avoid this we let an array of oops be an
|
||
|
|
// array of a primitive type of the same size until the clearing has completed.
|
||
|
|
// A max segment size of 64K was chosen because benchmarking suggests that is
|
||
|
|
// offers a good trade-off between allocation time and time-to-safepoint.
|
||
|
|
|
||
|
|
static Klass* substitute_object_array_klass(Klass* klass) {
|
||
|
|
if (!klass->is_objArray_klass()) {
|
||
|
|
return klass;
|
||
|
|
}
|
||
|
|
|
||
|
|
Klass* const substitute_klass = Universe::longArrayKlassObj();
|
||
|
|
const BasicType type = ArrayKlass::cast(klass)->element_type();
|
||
|
|
const BasicType substitute_type = ArrayKlass::cast(substitute_klass)->element_type();
|
||
|
|
assert(type2aelembytes(type) == type2aelembytes(substitute_type), "Element size mismatch");
|
||
|
|
return substitute_klass;
|
||
|
|
}
|
||
|
|
|
||
|
|
ZObjArrayAllocator::ZObjArrayAllocator(Klass* klass, size_t word_size, int length, Thread* thread) :
|
||
|
|
ObjArrayAllocator(substitute_object_array_klass(klass), word_size, length, false /* do_zero */, thread),
|
||
|
|
_final_klass(klass) {}
|
||
|
|
|
||
|
|
oop ZObjArrayAllocator::finish(HeapWord* mem) const {
|
||
|
|
HandleMark hm;
|
||
|
|
Handle array(_thread, ObjArrayAllocator::finish(mem));
|
||
|
|
|
||
|
|
const size_t segment_max = ZUtils::bytes_to_words(64 * K);
|
||
|
|
const size_t skip = arrayOopDesc::header_size(ArrayKlass::cast(_klass)->element_type());
|
||
|
|
size_t remaining = _word_size - skip;
|
||
|
|
|
||
|
|
while (remaining > 0) {
|
||
|
|
// Clear segment
|
||
|
|
const size_t segment = MIN2(remaining, segment_max);
|
||
|
|
Copy::zero_to_words((HeapWord*)array() + (_word_size - remaining), segment);
|
||
|
|
remaining -= segment;
|
||
|
|
|
||
|
|
if (remaining > 0) {
|
||
|
|
// Safepoint
|
||
|
|
ThreadBlockInVM tbivm((JavaThread*)_thread);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if (_klass != _final_klass) {
|
||
|
|
// Set final klass
|
||
|
|
oopDesc::release_set_klass((HeapWord*)array(), _final_klass);
|
||
|
|
}
|
||
|
|
|
||
|
|
return array();
|
||
|
|
}
|