36 // Class to create a "fake" oop with a mark that will
37 // return true for calls to must_be_preserved().
38 class FakeOop {
39 oopDesc _oop;
40
41 public:
42 FakeOop() : _oop() { _oop.set_mark_raw(originalMark()); }
43
44 oop get_oop() { return &_oop; }
45 markWord mark() { return _oop.mark_raw(); }
46 void set_mark(markWord m) { _oop.set_mark_raw(m); }
47 void forward_to(oop obj) {
48 markWord m = markWord::encode_pointer_as_mark(obj);
49 _oop.set_mark_raw(m);
50 }
51
52 static markWord originalMark() { return markWord(markWord::lock_mask_in_place); }
53 static markWord changedMark() { return markWord(0x4711); }
54 };
55
56 TEST_VM(PreservedMarks, iterate_and_restore) {
57 // Need to disable biased locking to easily
58 // create oops that "must_be_preseved"
59 ScopedDisabledBiasedLocking dbl;
60
61 PreservedMarks pm;
62 FakeOop o1;
63 FakeOop o2;
64 FakeOop o3;
65 FakeOop o4;
66
67 // Make sure initial marks are correct.
68 ASSERT_EQ(o1.mark(), FakeOop::originalMark());
69 ASSERT_EQ(o2.mark(), FakeOop::originalMark());
70 ASSERT_EQ(o3.mark(), FakeOop::originalMark());
71 ASSERT_EQ(o4.mark(), FakeOop::originalMark());
72
73 // Change the marks and verify change.
74 o1.set_mark(FakeOop::changedMark());
75 o2.set_mark(FakeOop::changedMark());
76 ASSERT_EQ(o1.mark(), FakeOop::changedMark());
77 ASSERT_EQ(o2.mark(), FakeOop::changedMark());
78
79 // Push o1 and o2 to have their marks preserved.
80 pm.push(o1.get_oop(), o1.mark());
81 pm.push(o2.get_oop(), o2.mark());
82
83 // Fake a move from o1->o3 and o2->o4.
84 o1.forward_to(o3.get_oop());
85 o2.forward_to(o4.get_oop());
86 ASSERT_EQ(o1.get_oop()->forwardee(), o3.get_oop());
87 ASSERT_EQ(o2.get_oop()->forwardee(), o4.get_oop());
88 // Adjust will update the PreservedMarks stack to
89 // make sure the mark is updated at the new location.
90 pm.adjust_during_full_gc();
91
92 // Restore all preserved and verify that the changed
93 // mark is now present at o3 and o4.
94 pm.restore();
95 ASSERT_EQ(o3.mark(), FakeOop::changedMark());
96 ASSERT_EQ(o4.mark(), FakeOop::changedMark());
97 }
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36 // Class to create a "fake" oop with a mark that will
37 // return true for calls to must_be_preserved().
38 class FakeOop {
39 oopDesc _oop;
40
41 public:
42 FakeOop() : _oop() { _oop.set_mark_raw(originalMark()); }
43
44 oop get_oop() { return &_oop; }
45 markWord mark() { return _oop.mark_raw(); }
46 void set_mark(markWord m) { _oop.set_mark_raw(m); }
47 void forward_to(oop obj) {
48 markWord m = markWord::encode_pointer_as_mark(obj);
49 _oop.set_mark_raw(m);
50 }
51
52 static markWord originalMark() { return markWord(markWord::lock_mask_in_place); }
53 static markWord changedMark() { return markWord(0x4711); }
54 };
55
56 #define ASSERT_MARK_WORD_EQ(a, b) ASSERT_EQ((a).value(), (b).value())
57
58 TEST_VM(PreservedMarks, iterate_and_restore) {
59 // Need to disable biased locking to easily
60 // create oops that "must_be_preseved"
61 ScopedDisabledBiasedLocking dbl;
62
63 PreservedMarks pm;
64 FakeOop o1;
65 FakeOop o2;
66 FakeOop o3;
67 FakeOop o4;
68
69 // Make sure initial marks are correct.
70 ASSERT_MARK_WORD_EQ(o1.mark(), FakeOop::originalMark());
71 ASSERT_MARK_WORD_EQ(o2.mark(), FakeOop::originalMark());
72 ASSERT_MARK_WORD_EQ(o3.mark(), FakeOop::originalMark());
73 ASSERT_MARK_WORD_EQ(o4.mark(), FakeOop::originalMark());
74
75 // Change the marks and verify change.
76 o1.set_mark(FakeOop::changedMark());
77 o2.set_mark(FakeOop::changedMark());
78 ASSERT_MARK_WORD_EQ(o1.mark(), FakeOop::changedMark());
79 ASSERT_MARK_WORD_EQ(o2.mark(), FakeOop::changedMark());
80
81 // Push o1 and o2 to have their marks preserved.
82 pm.push(o1.get_oop(), o1.mark());
83 pm.push(o2.get_oop(), o2.mark());
84
85 // Fake a move from o1->o3 and o2->o4.
86 o1.forward_to(o3.get_oop());
87 o2.forward_to(o4.get_oop());
88 ASSERT_EQ(o1.get_oop()->forwardee(), o3.get_oop());
89 ASSERT_EQ(o2.get_oop()->forwardee(), o4.get_oop());
90 // Adjust will update the PreservedMarks stack to
91 // make sure the mark is updated at the new location.
92 pm.adjust_during_full_gc();
93
94 // Restore all preserved and verify that the changed
95 // mark is now present at o3 and o4.
96 pm.restore();
97 ASSERT_MARK_WORD_EQ(o3.mark(), FakeOop::changedMark());
98 ASSERT_MARK_WORD_EQ(o4.mark(), FakeOop::changedMark());
99 }
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