8204210: Implementation: JEP 333: ZGC: A Scalable Low-Latency Garbage Collector (Experimental)
Reviewed-by: pliden, stefank, eosterlund, ehelin, sjohanss, rbackman, coleenp, ihse, jgeorge, lmesnik, rkennke
Contributed-by: per.liden@oracle.com, stefan.karlsson@oracle.com, erik.osterlund@oracle.com, mikael.gerdin@oracle.com, kim.barrett@oracle.com, nils.eliasson@oracle.com, rickard.backman@oracle.com, rwestrel@redhat.com, coleen.phillimore@oracle.com, robbin.ehn@oracle.com, gerard.ziemski@oracle.com, hugh.wilkinson@intel.com, sandhya.viswanathan@intel.com, bill.npo.wheeler@intel.com, vinay.k.awasthi@intel.com, yasuenag@gmail.com
/*
* Copyright (c) 2015, 2017, 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
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*/
#include "precompiled.hpp"
#include "gc/z/zPage.inline.hpp"
#include "gc/z/zPageTable.inline.hpp"
#include "runtime/orderAccess.hpp"
#include "utilities/debug.hpp"
ZPageTable::ZPageTable() :
_map() {}
ZPageTableEntry ZPageTable::get_entry(ZPage* page) const {
const uintptr_t addr = ZAddress::good(page->start());
return _map.get(addr);
}
void ZPageTable::put_entry(ZPage* page, ZPageTableEntry entry) {
// Make sure a newly created page is globally visible before
// updating the pagetable.
OrderAccess::storestore();
const uintptr_t start = ZAddress::good(page->start());
const uintptr_t end = start + page->size();
for (uintptr_t addr = start; addr < end; addr += ZPageSizeMin) {
_map.put(addr, entry);
}
}
void ZPageTable::insert(ZPage* page) {
assert(get_entry(page).page() == NULL ||
get_entry(page).page() == page, "Invalid entry");
// Cached pages stays in the pagetable and we must not re-insert
// those when they get re-allocated because they might also be
// relocating and we don't want to clear their relocating bit.
if (get_entry(page).page() == NULL) {
ZPageTableEntry entry(page, false /* relocating */);
put_entry(page, entry);
}
assert(get_entry(page).page() == page, "Invalid entry");
}
void ZPageTable::remove(ZPage* page) {
assert(get_entry(page).page() == page, "Invalid entry");
ZPageTableEntry entry;
put_entry(page, entry);
assert(get_entry(page).page() == NULL, "Invalid entry");
}
void ZPageTable::set_relocating(ZPage* page) {
assert(get_entry(page).page() == page, "Invalid entry");
assert(!get_entry(page).relocating(), "Invalid entry");
ZPageTableEntry entry(page, true /* relocating */);
put_entry(page, entry);
assert(get_entry(page).page() == page, "Invalid entry");
assert(get_entry(page).relocating(), "Invalid entry");
}
void ZPageTable::clear_relocating(ZPage* page) {
assert(get_entry(page).page() == page, "Invalid entry");
assert(get_entry(page).relocating(), "Invalid entry");
ZPageTableEntry entry(page, false /* relocating */);
put_entry(page, entry);
assert(get_entry(page).page() == page, "Invalid entry");
assert(!get_entry(page).relocating(), "Invalid entry");
}