Sat, 31 Jan 2009 00:15:00 -0800
6792421: assert(_bitMap->isMarked(addr+size-1),inconsistent Printezis mark)
Summary: The CMS concurrent precleaning and concurrent marking phases should work around classes that are undergoing redefinition.
Reviewed-by: ysr, tonyp
1 /*
2 * Copyright 2001-2008 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
25 # include "incls/_precompiled.incl"
26 # include "incls/_collectedHeap.cpp.incl"
29 #ifdef ASSERT
30 int CollectedHeap::_fire_out_of_memory_count = 0;
31 #endif
33 size_t CollectedHeap::_filler_array_max_size = 0;
35 // Memory state functions.
37 CollectedHeap::CollectedHeap()
38 {
39 const size_t max_len = size_t(arrayOopDesc::max_array_length(T_INT));
40 const size_t elements_per_word = HeapWordSize / sizeof(jint);
41 _filler_array_max_size = align_object_size(filler_array_hdr_size() +
42 max_len * elements_per_word);
44 _barrier_set = NULL;
45 _is_gc_active = false;
46 _total_collections = _total_full_collections = 0;
47 _gc_cause = _gc_lastcause = GCCause::_no_gc;
48 NOT_PRODUCT(_promotion_failure_alot_count = 0;)
49 NOT_PRODUCT(_promotion_failure_alot_gc_number = 0;)
51 if (UsePerfData) {
52 EXCEPTION_MARK;
54 // create the gc cause jvmstat counters
55 _perf_gc_cause = PerfDataManager::create_string_variable(SUN_GC, "cause",
56 80, GCCause::to_string(_gc_cause), CHECK);
58 _perf_gc_lastcause =
59 PerfDataManager::create_string_variable(SUN_GC, "lastCause",
60 80, GCCause::to_string(_gc_lastcause), CHECK);
61 }
62 }
65 #ifndef PRODUCT
66 void CollectedHeap::check_for_bad_heap_word_value(HeapWord* addr, size_t size) {
67 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
68 for (size_t slot = 0; slot < size; slot += 1) {
69 assert((*(intptr_t*) (addr + slot)) != ((intptr_t) badHeapWordVal),
70 "Found badHeapWordValue in post-allocation check");
71 }
72 }
73 }
75 void CollectedHeap::check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
76 {
77 if (CheckMemoryInitialization && ZapUnusedHeapArea) {
78 for (size_t slot = 0; slot < size; slot += 1) {
79 assert((*(intptr_t*) (addr + slot)) == ((intptr_t) badHeapWordVal),
80 "Found non badHeapWordValue in pre-allocation check");
81 }
82 }
83 }
84 #endif // PRODUCT
86 #ifdef ASSERT
87 void CollectedHeap::check_for_valid_allocation_state() {
88 Thread *thread = Thread::current();
89 // How to choose between a pending exception and a potential
90 // OutOfMemoryError? Don't allow pending exceptions.
91 // This is a VM policy failure, so how do we exhaustively test it?
92 assert(!thread->has_pending_exception(),
93 "shouldn't be allocating with pending exception");
94 if (StrictSafepointChecks) {
95 assert(thread->allow_allocation(),
96 "Allocation done by thread for which allocation is blocked "
97 "by No_Allocation_Verifier!");
98 // Allocation of an oop can always invoke a safepoint,
99 // hence, the true argument
100 thread->check_for_valid_safepoint_state(true);
101 }
102 }
103 #endif
105 HeapWord* CollectedHeap::allocate_from_tlab_slow(Thread* thread, size_t size) {
107 // Retain tlab and allocate object in shared space if
108 // the amount free in the tlab is too large to discard.
109 if (thread->tlab().free() > thread->tlab().refill_waste_limit()) {
110 thread->tlab().record_slow_allocation(size);
111 return NULL;
112 }
114 // Discard tlab and allocate a new one.
115 // To minimize fragmentation, the last TLAB may be smaller than the rest.
116 size_t new_tlab_size = thread->tlab().compute_size(size);
118 thread->tlab().clear_before_allocation();
120 if (new_tlab_size == 0) {
121 return NULL;
122 }
124 // Allocate a new TLAB...
125 HeapWord* obj = Universe::heap()->allocate_new_tlab(new_tlab_size);
126 if (obj == NULL) {
127 return NULL;
128 }
129 if (ZeroTLAB) {
130 // ..and clear it.
131 Copy::zero_to_words(obj, new_tlab_size);
132 } else {
133 // ...and clear just the allocated object.
134 Copy::zero_to_words(obj, size);
135 }
136 thread->tlab().fill(obj, obj + size, new_tlab_size);
137 return obj;
138 }
140 size_t CollectedHeap::filler_array_hdr_size() {
141 return size_t(arrayOopDesc::header_size(T_INT));
142 }
144 size_t CollectedHeap::filler_array_min_size() {
145 return align_object_size(filler_array_hdr_size());
146 }
148 size_t CollectedHeap::filler_array_max_size() {
149 return _filler_array_max_size;
150 }
152 #ifdef ASSERT
153 void CollectedHeap::fill_args_check(HeapWord* start, size_t words)
154 {
155 assert(words >= min_fill_size(), "too small to fill");
156 assert(words % MinObjAlignment == 0, "unaligned size");
157 assert(Universe::heap()->is_in_reserved(start), "not in heap");
158 assert(Universe::heap()->is_in_reserved(start + words - 1), "not in heap");
159 }
161 void CollectedHeap::zap_filler_array(HeapWord* start, size_t words)
162 {
163 if (ZapFillerObjects) {
164 Copy::fill_to_words(start + filler_array_hdr_size(),
165 words - filler_array_hdr_size(), 0XDEAFBABE);
166 }
167 }
168 #endif // ASSERT
170 void
171 CollectedHeap::fill_with_array(HeapWord* start, size_t words)
172 {
173 assert(words >= filler_array_min_size(), "too small for an array");
174 assert(words <= filler_array_max_size(), "too big for a single object");
176 const size_t payload_size = words - filler_array_hdr_size();
177 const size_t len = payload_size * HeapWordSize / sizeof(jint);
179 // Set the length first for concurrent GC.
180 ((arrayOop)start)->set_length((int)len);
181 post_allocation_setup_common(Universe::intArrayKlassObj(), start, words);
182 DEBUG_ONLY(zap_filler_array(start, words);)
183 }
185 void
186 CollectedHeap::fill_with_object_impl(HeapWord* start, size_t words)
187 {
188 assert(words <= filler_array_max_size(), "too big for a single object");
190 if (words >= filler_array_min_size()) {
191 fill_with_array(start, words);
192 } else if (words > 0) {
193 assert(words == min_fill_size(), "unaligned size");
194 post_allocation_setup_common(SystemDictionary::object_klass(), start,
195 words);
196 }
197 }
199 void CollectedHeap::fill_with_object(HeapWord* start, size_t words)
200 {
201 DEBUG_ONLY(fill_args_check(start, words);)
202 HandleMark hm; // Free handles before leaving.
203 fill_with_object_impl(start, words);
204 }
206 void CollectedHeap::fill_with_objects(HeapWord* start, size_t words)
207 {
208 DEBUG_ONLY(fill_args_check(start, words);)
209 HandleMark hm; // Free handles before leaving.
211 #ifdef LP64
212 // A single array can fill ~8G, so multiple objects are needed only in 64-bit.
213 // First fill with arrays, ensuring that any remaining space is big enough to
214 // fill. The remainder is filled with a single object.
215 const size_t min = min_fill_size();
216 const size_t max = filler_array_max_size();
217 while (words > max) {
218 const size_t cur = words - max >= min ? max : max - min;
219 fill_with_array(start, cur);
220 start += cur;
221 words -= cur;
222 }
223 #endif
225 fill_with_object_impl(start, words);
226 }
228 oop CollectedHeap::new_store_barrier(oop new_obj) {
229 // %%% This needs refactoring. (It was imported from the server compiler.)
230 guarantee(can_elide_tlab_store_barriers(), "store barrier elision not supported");
231 BarrierSet* bs = this->barrier_set();
232 assert(bs->has_write_region_opt(), "Barrier set does not have write_region");
233 int new_size = new_obj->size();
234 bs->write_region(MemRegion((HeapWord*)new_obj, new_size));
235 return new_obj;
236 }
238 HeapWord* CollectedHeap::allocate_new_tlab(size_t size) {
239 guarantee(false, "thread-local allocation buffers not supported");
240 return NULL;
241 }
243 void CollectedHeap::fill_all_tlabs(bool retire) {
244 assert(UseTLAB, "should not reach here");
245 // See note in ensure_parsability() below.
246 assert(SafepointSynchronize::is_at_safepoint() ||
247 !is_init_completed(),
248 "should only fill tlabs at safepoint");
249 // The main thread starts allocating via a TLAB even before it
250 // has added itself to the threads list at vm boot-up.
251 assert(Threads::first() != NULL,
252 "Attempt to fill tlabs before main thread has been added"
253 " to threads list is doomed to failure!");
254 for(JavaThread *thread = Threads::first(); thread; thread = thread->next()) {
255 thread->tlab().make_parsable(retire);
256 }
257 }
259 void CollectedHeap::ensure_parsability(bool retire_tlabs) {
260 // The second disjunct in the assertion below makes a concession
261 // for the start-up verification done while the VM is being
262 // created. Callers be careful that you know that mutators
263 // aren't going to interfere -- for instance, this is permissible
264 // if we are still single-threaded and have either not yet
265 // started allocating (nothing much to verify) or we have
266 // started allocating but are now a full-fledged JavaThread
267 // (and have thus made our TLAB's) available for filling.
268 assert(SafepointSynchronize::is_at_safepoint() ||
269 !is_init_completed(),
270 "Should only be called at a safepoint or at start-up"
271 " otherwise concurrent mutator activity may make heap "
272 " unparsable again");
273 if (UseTLAB) {
274 fill_all_tlabs(retire_tlabs);
275 }
276 }
278 void CollectedHeap::accumulate_statistics_all_tlabs() {
279 if (UseTLAB) {
280 assert(SafepointSynchronize::is_at_safepoint() ||
281 !is_init_completed(),
282 "should only accumulate statistics on tlabs at safepoint");
284 ThreadLocalAllocBuffer::accumulate_statistics_before_gc();
285 }
286 }
288 void CollectedHeap::resize_all_tlabs() {
289 if (UseTLAB) {
290 assert(SafepointSynchronize::is_at_safepoint() ||
291 !is_init_completed(),
292 "should only resize tlabs at safepoint");
294 ThreadLocalAllocBuffer::resize_all_tlabs();
295 }
296 }