1 /* 2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #include "precompiled.hpp" 26 #include "memory/metaspaceClosure.hpp" 27 28 // Update the reference to point to new_loc. 29 void MetaspaceClosure::Ref::update(address new_loc) const { 30 log_trace(cds)("Ref: [" PTR_FORMAT "] -> " PTR_FORMAT " => " PTR_FORMAT, 31 p2i(mpp()), p2i(obj()), p2i(new_loc)); 32 uintx p = (uintx)new_loc; 33 p |= flag_bits(); // Make sure the flag bits are copied to the new pointer. 34 *(address*)mpp() = (address)p; 35 } 36 37 void MetaspaceClosure::push_impl(MetaspaceClosure::Ref* ref, Writability w) { 38 if (ref->not_null()) { 39 bool read_only; 40 switch (w) { 41 case _writable: 42 read_only = false; 43 break; 44 case _not_writable: 45 read_only = true; 46 break; 47 default: 48 assert(w == _default, "must be"); 49 read_only = ref->is_read_only_by_default(); 50 } 51 if (do_ref(ref, read_only)) { // true means we want to iterate the embedded pointer in <ref> 52 ref->metaspace_pointers_do(this); 53 } 54 } 55 } 56 57 bool UniqueMetaspaceClosure::do_ref(MetaspaceClosure::Ref* ref, bool read_only) { 58 bool* found = _has_been_visited.get(ref->obj()); 59 if (found != NULL) { 60 assert(*found == read_only, "must be"); 61 return false; // Already visited: no need to iterate embedded pointers. 62 } else { 63 bool isnew = _has_been_visited.put(ref->obj(), read_only); 64 assert(isnew, "sanity"); 65 do_unique_ref(ref, read_only); 66 return true; // Saw this for the first time: iterate the embedded pointers. 67 } 68 }