Fri, 14 Mar 2014 10:15:46 +0100
8034079: G1: Refactor the HeapRegionSet hierarchy
Reviewed-by: tschatzl, pliden
1 /*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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25 #include "precompiled.hpp"
26 #include "gc_implementation/g1/heapRegionRemSet.hpp"
27 #include "gc_implementation/g1/heapRegionSet.inline.hpp"
29 uint FreeRegionList::_unrealistically_long_length = 0;
31 void HeapRegionSetBase::fill_in_ext_msg(hrs_ext_msg* msg, const char* message) {
32 msg->append("[%s] %s ln: %u cy: "SIZE_FORMAT,
33 name(), message, length(), total_capacity_bytes());
34 fill_in_ext_msg_extra(msg);
35 }
37 #ifndef PRODUCT
38 void HeapRegionSetBase::verify_region(HeapRegion* hr) {
39 assert(hr->containing_set() == this, err_msg("Inconsistent containing set for %u", hr->hrs_index()));
40 assert(!hr->is_young(), err_msg("Adding young region %u", hr->hrs_index())); // currently we don't use these sets for young regions
41 assert(hr->isHumongous() == regions_humongous(), err_msg("Wrong humongous state for region %u and set %s", hr->hrs_index(), name()));
42 assert(hr->is_empty() == regions_empty(), err_msg("Wrong empty state for region %u and set %s", hr->hrs_index(), name()));
43 assert(hr->rem_set()->verify_ready_for_par_iteration(), err_msg("Wrong iteration state %u", hr->hrs_index()));
44 }
45 #endif
47 void HeapRegionSetBase::verify() {
48 // It's important that we also observe the MT safety protocol even
49 // for the verification calls. If we do verification without the
50 // appropriate locks and the set changes underneath our feet
51 // verification might fail and send us on a wild goose chase.
52 check_mt_safety();
54 guarantee(( is_empty() && length() == 0 && total_capacity_bytes() == 0) ||
55 (!is_empty() && length() >= 0 && total_capacity_bytes() >= 0),
56 hrs_ext_msg(this, "invariant"));
57 }
59 void HeapRegionSetBase::verify_start() {
60 // See comment in verify() about MT safety and verification.
61 check_mt_safety();
62 assert(!_verify_in_progress,
63 hrs_ext_msg(this, "verification should not be in progress"));
65 // Do the basic verification first before we do the checks over the regions.
66 HeapRegionSetBase::verify();
68 _verify_in_progress = true;
69 }
71 void HeapRegionSetBase::verify_end() {
72 // See comment in verify() about MT safety and verification.
73 check_mt_safety();
74 assert(_verify_in_progress,
75 hrs_ext_msg(this, "verification should be in progress"));
77 _verify_in_progress = false;
78 }
80 void HeapRegionSetBase::print_on(outputStream* out, bool print_contents) {
81 out->cr();
82 out->print_cr("Set: %s ("PTR_FORMAT")", name(), this);
83 out->print_cr(" Region Assumptions");
84 out->print_cr(" humongous : %s", BOOL_TO_STR(regions_humongous()));
85 out->print_cr(" empty : %s", BOOL_TO_STR(regions_empty()));
86 out->print_cr(" Attributes");
87 out->print_cr(" length : %14u", length());
88 out->print_cr(" total capacity : "SIZE_FORMAT_W(14)" bytes",
89 total_capacity_bytes());
90 }
92 HeapRegionSetBase::HeapRegionSetBase(const char* name, bool humongous, bool empty, HRSMtSafeChecker* mt_safety_checker)
93 : _name(name), _verify_in_progress(false),
94 _is_humongous(humongous), _is_empty(empty), _mt_safety_checker(mt_safety_checker),
95 _count()
96 { }
98 void FreeRegionList::set_unrealistically_long_length(uint len) {
99 guarantee(_unrealistically_long_length == 0, "should only be set once");
100 _unrealistically_long_length = len;
101 }
103 void FreeRegionList::fill_in_ext_msg_extra(hrs_ext_msg* msg) {
104 msg->append(" hd: "PTR_FORMAT" tl: "PTR_FORMAT, head(), tail());
105 }
107 void FreeRegionList::add_as_head_or_tail(FreeRegionList* from_list, bool as_head) {
108 check_mt_safety();
109 from_list->check_mt_safety();
111 verify_optional();
112 from_list->verify_optional();
114 if (from_list->is_empty()) {
115 return;
116 }
118 #ifdef ASSERT
119 FreeRegionListIterator iter(from_list);
120 while (iter.more_available()) {
121 HeapRegion* hr = iter.get_next();
122 // In set_containing_set() we check that we either set the value
123 // from NULL to non-NULL or vice versa to catch bugs. So, we have
124 // to NULL it first before setting it to the value.
125 hr->set_containing_set(NULL);
126 hr->set_containing_set(this);
127 }
128 #endif // ASSERT
130 if (_head == NULL) {
131 assert(length() == 0 && _tail == NULL, hrs_ext_msg(this, "invariant"));
132 _head = from_list->_head;
133 _tail = from_list->_tail;
134 } else {
135 assert(length() > 0 && _tail != NULL, hrs_ext_msg(this, "invariant"));
136 if (as_head) {
137 from_list->_tail->set_next(_head);
138 _head = from_list->_head;
139 } else {
140 _tail->set_next(from_list->_head);
141 _tail = from_list->_tail;
142 }
143 }
145 _count.increment(from_list->length(), from_list->total_capacity_bytes());
146 from_list->clear();
148 verify_optional();
149 from_list->verify_optional();
150 }
152 void FreeRegionList::add_as_head(FreeRegionList* from_list) {
153 add_as_head_or_tail(from_list, true /* as_head */);
154 }
156 void FreeRegionList::add_as_tail(FreeRegionList* from_list) {
157 add_as_head_or_tail(from_list, false /* as_head */);
158 }
160 void FreeRegionList::remove_all() {
161 check_mt_safety();
162 verify_optional();
164 HeapRegion* curr = _head;
165 while (curr != NULL) {
166 verify_region(curr);
168 HeapRegion* next = curr->next();
169 curr->set_next(NULL);
170 curr->set_containing_set(NULL);
171 curr = next;
172 }
173 clear();
175 verify_optional();
176 }
178 void FreeRegionList::remove_all_pending(uint target_count) {
179 check_mt_safety();
180 assert(target_count > 1, hrs_ext_msg(this, "pre-condition"));
181 assert(!is_empty(), hrs_ext_msg(this, "pre-condition"));
183 verify_optional();
184 DEBUG_ONLY(uint old_length = length();)
186 HeapRegion* curr = _head;
187 HeapRegion* prev = NULL;
188 uint count = 0;
189 while (curr != NULL) {
190 verify_region(curr);
191 HeapRegion* next = curr->next();
193 if (curr->pending_removal()) {
194 assert(count < target_count,
195 hrs_err_msg("[%s] should not come across more regions "
196 "pending for removal than target_count: %u",
197 name(), target_count));
199 if (prev == NULL) {
200 assert(_head == curr, hrs_ext_msg(this, "invariant"));
201 _head = next;
202 } else {
203 assert(_head != curr, hrs_ext_msg(this, "invariant"));
204 prev->set_next(next);
205 }
206 if (next == NULL) {
207 assert(_tail == curr, hrs_ext_msg(this, "invariant"));
208 _tail = prev;
209 } else {
210 assert(_tail != curr, hrs_ext_msg(this, "invariant"));
211 }
213 curr->set_next(NULL);
214 remove(curr);
215 curr->set_pending_removal(false);
217 count += 1;
219 // If we have come across the target number of regions we can
220 // just bail out. However, for debugging purposes, we can just
221 // carry on iterating to make sure there are not more regions
222 // tagged with pending removal.
223 DEBUG_ONLY(if (count == target_count) break;)
224 } else {
225 prev = curr;
226 }
227 curr = next;
228 }
230 assert(count == target_count,
231 hrs_err_msg("[%s] count: %u should be == target_count: %u",
232 name(), count, target_count));
233 assert(length() + target_count == old_length,
234 hrs_err_msg("[%s] new length should be consistent "
235 "new length: %u old length: %u target_count: %u",
236 name(), length(), old_length, target_count));
238 verify_optional();
239 }
241 void FreeRegionList::verify() {
242 // See comment in HeapRegionSetBase::verify() about MT safety and
243 // verification.
244 check_mt_safety();
246 // This will also do the basic verification too.
247 verify_start();
249 verify_list();
251 verify_end();
252 }
254 void FreeRegionList::clear() {
255 _count = HeapRegionSetCount();
256 _head = NULL;
257 _tail = NULL;
258 }
260 void FreeRegionList::print_on(outputStream* out, bool print_contents) {
261 HeapRegionSetBase::print_on(out, print_contents);
262 out->print_cr(" Linking");
263 out->print_cr(" head : "PTR_FORMAT, _head);
264 out->print_cr(" tail : "PTR_FORMAT, _tail);
266 if (print_contents) {
267 out->print_cr(" Contents");
268 FreeRegionListIterator iter(this);
269 while (iter.more_available()) {
270 HeapRegion* hr = iter.get_next();
271 hr->print_on(out);
272 }
273 }
274 }