Mon, 24 Mar 2014 15:30:14 +0100
8035406: Improve data structure for Code Cache remembered sets
Summary: Change the code cache remembered sets data structure from a GrowableArray to a chunked list of nmethods. This makes the data structure more amenable to parallelization, and decreases freeing time.
Reviewed-by: mgerdin, brutisso
1 /*
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23 */
25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/g1SATBCardTableModRefBS.hpp"
27 #include "gc_implementation/g1/heapRegion.hpp"
28 #include "gc_implementation/g1/satbQueue.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "runtime/thread.inline.hpp"
32 G1SATBCardTableModRefBS::G1SATBCardTableModRefBS(MemRegion whole_heap,
33 int max_covered_regions) :
34 CardTableModRefBSForCTRS(whole_heap, max_covered_regions)
35 {
36 _kind = G1SATBCT;
37 }
40 void G1SATBCardTableModRefBS::enqueue(oop pre_val) {
41 // Nulls should have been already filtered.
42 assert(pre_val->is_oop(true), "Error");
44 if (!JavaThread::satb_mark_queue_set().is_active()) return;
45 Thread* thr = Thread::current();
46 if (thr->is_Java_thread()) {
47 JavaThread* jt = (JavaThread*)thr;
48 jt->satb_mark_queue().enqueue(pre_val);
49 } else {
50 MutexLockerEx x(Shared_SATB_Q_lock, Mutex::_no_safepoint_check_flag);
51 JavaThread::satb_mark_queue_set().shared_satb_queue()->enqueue(pre_val);
52 }
53 }
55 template <class T> void
56 G1SATBCardTableModRefBS::write_ref_array_pre_work(T* dst, int count) {
57 if (!JavaThread::satb_mark_queue_set().is_active()) return;
58 T* elem_ptr = dst;
59 for (int i = 0; i < count; i++, elem_ptr++) {
60 T heap_oop = oopDesc::load_heap_oop(elem_ptr);
61 if (!oopDesc::is_null(heap_oop)) {
62 enqueue(oopDesc::decode_heap_oop_not_null(heap_oop));
63 }
64 }
65 }
67 bool G1SATBCardTableModRefBS::mark_card_deferred(size_t card_index) {
68 jbyte val = _byte_map[card_index];
69 // It's already processed
70 if ((val & (clean_card_mask_val() | deferred_card_val())) == deferred_card_val()) {
71 return false;
72 }
74 if (val == g1_young_gen) {
75 // the card is for a young gen region. We don't need to keep track of all pointers into young
76 return false;
77 }
79 // Cached bit can be installed either on a clean card or on a claimed card.
80 jbyte new_val = val;
81 if (val == clean_card_val()) {
82 new_val = (jbyte)deferred_card_val();
83 } else {
84 if (val & claimed_card_val()) {
85 new_val = val | (jbyte)deferred_card_val();
86 }
87 }
88 if (new_val != val) {
89 Atomic::cmpxchg(new_val, &_byte_map[card_index], val);
90 }
91 return true;
92 }
94 void G1SATBCardTableModRefBS::g1_mark_as_young(const MemRegion& mr) {
95 jbyte *const first = byte_for(mr.start());
96 jbyte *const last = byte_after(mr.last());
98 memset(first, g1_young_gen, last - first);
99 }
101 #ifndef PRODUCT
102 void G1SATBCardTableModRefBS::verify_g1_young_region(MemRegion mr) {
103 verify_region(mr, g1_young_gen, true);
104 }
105 #endif
107 G1SATBCardTableLoggingModRefBS::
108 G1SATBCardTableLoggingModRefBS(MemRegion whole_heap,
109 int max_covered_regions) :
110 G1SATBCardTableModRefBS(whole_heap, max_covered_regions),
111 _dcqs(JavaThread::dirty_card_queue_set())
112 {
113 _kind = G1SATBCTLogging;
114 }
116 void
117 G1SATBCardTableLoggingModRefBS::write_ref_field_work(void* field,
118 oop new_val) {
119 volatile jbyte* byte = byte_for(field);
120 if (*byte == g1_young_gen) {
121 return;
122 }
123 OrderAccess::storeload();
124 if (*byte != dirty_card) {
125 *byte = dirty_card;
126 Thread* thr = Thread::current();
127 if (thr->is_Java_thread()) {
128 JavaThread* jt = (JavaThread*)thr;
129 jt->dirty_card_queue().enqueue(byte);
130 } else {
131 MutexLockerEx x(Shared_DirtyCardQ_lock,
132 Mutex::_no_safepoint_check_flag);
133 _dcqs.shared_dirty_card_queue()->enqueue(byte);
134 }
135 }
136 }
138 void
139 G1SATBCardTableLoggingModRefBS::write_ref_field_static(void* field,
140 oop new_val) {
141 uintptr_t field_uint = (uintptr_t)field;
142 uintptr_t new_val_uint = cast_from_oop<uintptr_t>(new_val);
143 uintptr_t comb = field_uint ^ new_val_uint;
144 comb = comb >> HeapRegion::LogOfHRGrainBytes;
145 if (comb == 0) return;
146 if (new_val == NULL) return;
147 // Otherwise, log it.
148 G1SATBCardTableLoggingModRefBS* g1_bs =
149 (G1SATBCardTableLoggingModRefBS*)Universe::heap()->barrier_set();
150 g1_bs->write_ref_field_work(field, new_val);
151 }
153 void
154 G1SATBCardTableLoggingModRefBS::invalidate(MemRegion mr, bool whole_heap) {
155 volatile jbyte* byte = byte_for(mr.start());
156 jbyte* last_byte = byte_for(mr.last());
157 Thread* thr = Thread::current();
158 if (whole_heap) {
159 while (byte <= last_byte) {
160 *byte = dirty_card;
161 byte++;
162 }
163 } else {
164 // skip all consecutive young cards
165 for (; byte <= last_byte && *byte == g1_young_gen; byte++);
167 if (byte <= last_byte) {
168 OrderAccess::storeload();
169 // Enqueue if necessary.
170 if (thr->is_Java_thread()) {
171 JavaThread* jt = (JavaThread*)thr;
172 for (; byte <= last_byte; byte++) {
173 if (*byte == g1_young_gen) {
174 continue;
175 }
176 if (*byte != dirty_card) {
177 *byte = dirty_card;
178 jt->dirty_card_queue().enqueue(byte);
179 }
180 }
181 } else {
182 MutexLockerEx x(Shared_DirtyCardQ_lock,
183 Mutex::_no_safepoint_check_flag);
184 for (; byte <= last_byte; byte++) {
185 if (*byte == g1_young_gen) {
186 continue;
187 }
188 if (*byte != dirty_card) {
189 *byte = dirty_card;
190 _dcqs.shared_dirty_card_queue()->enqueue(byte);
191 }
192 }
193 }
194 }
195 }
196 }