/*
* 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 "memory/archiveUtils.hpp"
#include "memory/metaspace.hpp"
#include "utilities/bitMap.inline.hpp"
#if INCLUDE_CDS
CHeapBitMap* ArchivePtrMarker::_ptrmap = NULL;
address* ArchivePtrMarker::_ptr_base;
address* ArchivePtrMarker::_ptr_end;
bool ArchivePtrMarker::_compacted;
void ArchivePtrMarker::initialize(CHeapBitMap* ptrmap, address* ptr_base, address* ptr_end) {
assert(_ptrmap == NULL, "initialize only once");
_ptr_base = ptr_base;
_ptr_end = ptr_end;
_compacted = false;
_ptrmap = ptrmap;
// Use this as initial guesstimate. We should need less space in the
// archive, but if we're wrong the bitmap will be expanded automatically.
size_t estimated_archive_size = MetaspaceGC::capacity_until_GC();
// But set it smaller in debug builds so we always test the expansion code.
// (Default archive is about 12MB).
DEBUG_ONLY(estimated_archive_size = 6 * M);
// We need one bit per pointer in the archive.
_ptrmap->initialize(estimated_archive_size / sizeof(intptr_t));
}
void ArchivePtrMarker::mark_pointer(address* ptr_loc) {
assert(_ptrmap != NULL, "not initialized");
assert(!_compacted, "cannot mark anymore");
if (_ptr_base <= ptr_loc && ptr_loc < _ptr_end) {
address value = *ptr_loc;
if (value != NULL) {
assert(uintx(ptr_loc) % sizeof(intptr_t) == 0, "pointers must be stored in aligned addresses");
size_t idx = ptr_loc - _ptr_base;
if (_ptrmap->size() <= idx) {
_ptrmap->resize((idx + 1) * 2);
}
assert(idx < _ptrmap->size(), "must be");
_ptrmap->set_bit(idx);
//tty->print_cr("Marking pointer [%p] -> %p @ " SIZE_FORMAT_W(9), ptr_loc, *ptr_loc, idx);
}
}
}
class ArchivePtrBitmapCleaner: public BitMapClosure {
CHeapBitMap* _ptrmap;
address* _ptr_base;
address _relocatable_base;
address _relocatable_end;
size_t _max_non_null_offset;
public:
ArchivePtrBitmapCleaner(CHeapBitMap* ptrmap, address* ptr_base, address relocatable_base, address relocatable_end) :
_ptrmap(ptrmap), _ptr_base(ptr_base),
_relocatable_base(relocatable_base), _relocatable_end(relocatable_end), _max_non_null_offset(0) {}
bool do_bit(size_t offset) {
address* ptr_loc = _ptr_base + offset;
address ptr_value = *ptr_loc;
if (ptr_value != NULL) {
assert(_relocatable_base <= ptr_value && ptr_value < _relocatable_end, "do not point to arbitrary locations!");
if (_max_non_null_offset < offset) {
_max_non_null_offset = offset;
}
} else {
_ptrmap->clear_bit(offset);
DEBUG_ONLY(log_trace(cds, reloc)("Clearing pointer [" PTR_FORMAT "] -> NULL @ " SIZE_FORMAT_W(9), p2i(ptr_loc), offset));
}
return true;
}
size_t max_non_null_offset() const { return _max_non_null_offset; }
};
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