1 /* 2 * Copyright (c) 2017, 2025, 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 #include "gc/shared/preservedMarks.inline.hpp" 25 #include "gc/shared/fullGCForwarding.inline.hpp" 26 #include "oops/oop.inline.hpp" 27 #include "unittest.hpp" 28 29 static markWord originalMark() { return markWord(markWord::lock_mask_in_place); } 30 static markWord changedMark() { return markWord(0x4711); } 31 32 #define ASSERT_MARK_WORD_EQ(a, b) ASSERT_EQ((a).value(), (b).value()) 33 34 TEST_VM(PreservedMarks, iterate_and_restore) { 35 PreservedMarks pm; 36 37 HeapWord fakeheap[32] = { nullptr }; 38 HeapWord* heap = align_up(fakeheap, 8 * sizeof(HeapWord)); 39 FullGCForwarding::initialize(MemRegion(&heap[0], &heap[16])); 40 41 oop o1 = cast_to_oop(&heap[0]); o1->set_mark(originalMark()); 42 oop o2 = cast_to_oop(&heap[2]); o2->set_mark(originalMark()); 43 oop o3 = cast_to_oop(&heap[4]); o3->set_mark(originalMark()); 44 oop o4 = cast_to_oop(&heap[6]); o4->set_mark(originalMark()); 45 46 // Make sure initial marks are correct. 47 ASSERT_MARK_WORD_EQ(o1->mark(), originalMark()); 48 ASSERT_MARK_WORD_EQ(o2->mark(), originalMark()); 49 ASSERT_MARK_WORD_EQ(o3->mark(), originalMark()); 50 ASSERT_MARK_WORD_EQ(o4->mark(), originalMark()); 51 52 // Change the marks and verify change. 53 o1->set_mark(changedMark()); 54 o2->set_mark(changedMark()); 55 ASSERT_MARK_WORD_EQ(o1->mark(), changedMark()); 56 ASSERT_MARK_WORD_EQ(o2->mark(), changedMark()); 57 58 // Push o1 and o2 to have their marks preserved. 59 pm.push_if_necessary(o1, o1->mark()); 60 pm.push_if_necessary(o2, o2->mark()); 61 62 // Fake a move from o1->o3 and o2->o4. 63 FullGCForwarding::forward_to(o1, o3); 64 FullGCForwarding::forward_to(o2, o4); 65 ASSERT_EQ(FullGCForwarding::forwardee(o1), o3); 66 ASSERT_EQ(FullGCForwarding::forwardee(o2), o4); 67 // Adjust will update the PreservedMarks stack to 68 // make sure the mark is updated at the new location. 69 pm.adjust_during_full_gc(); 70 71 // Restore all preserved and verify that the changed 72 // mark is now present at o3 and o4. 73 pm.restore(); 74 ASSERT_MARK_WORD_EQ(o3->mark(), changedMark()); 75 ASSERT_MARK_WORD_EQ(o4->mark(), changedMark()); 76 }