1 /*
2 * Copyright (c) 2001, 2009, 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
25 // Inline allocation implementations.
26
27 void CollectedHeap::post_allocation_setup_common(KlassHandle klass,
28 HeapWord* obj,
29 size_t size) {
30 post_allocation_setup_no_klass_install(klass, obj, size);
31 post_allocation_install_obj_klass(klass, oop(obj), (int) size);
32 }
33
34 void CollectedHeap::post_allocation_setup_no_klass_install(KlassHandle klass,
35 HeapWord* objPtr,
36 size_t size) {
37 oop obj = (oop)objPtr;
38
39 assert(obj != NULL, "NULL object pointer");
40 if (UseBiasedLocking && (klass() != NULL)) {
41 obj->set_mark(klass->prototype_header());
42 } else {
43 // May be bootstrapping
44 obj->set_mark(markOopDesc::prototype());
45 }
46 }
47
48 void CollectedHeap::post_allocation_install_obj_klass(KlassHandle klass,
49 oop obj,
50 int size) {
51 // These asserts are kind of complicated because of klassKlass
52 // and the beginning of the world.
53 assert(klass() != NULL || !Universe::is_fully_initialized(), "NULL klass");
54 assert(klass() == NULL || klass()->is_klass(), "not a klass");
55 assert(klass() == NULL || klass()->klass_part() != NULL, "not a klass");
56 assert(obj != NULL, "NULL object pointer");
57 obj->set_klass(klass());
58 assert(!Universe::is_fully_initialized() || obj->blueprint() != NULL,
59 "missing blueprint");
60 }
61
62 // Support for jvmti and dtrace
63 inline void post_allocation_notify(KlassHandle klass, oop obj) {
64 // support low memory notifications (no-op if not enabled)
65 LowMemoryDetector::detect_low_memory_for_collected_pools();
66
67 // support for JVMTI VMObjectAlloc event (no-op if not enabled)
68 JvmtiExport::vm_object_alloc_event_collector(obj);
69
70 if (DTraceAllocProbes) {
71 // support for Dtrace object alloc event (no-op most of the time)
72 if (klass() != NULL && klass()->klass_part()->name() != NULL) {
73 SharedRuntime::dtrace_object_alloc(obj);
74 }
75 }
76 }
77
78 void CollectedHeap::post_allocation_setup_obj(KlassHandle klass,
79 HeapWord* obj,
80 size_t size) {
81 post_allocation_setup_common(klass, obj, size);
82 assert(Universe::is_bootstrapping() ||
83 !((oop)obj)->blueprint()->oop_is_array(), "must not be an array");
84 // notify jvmti and dtrace
85 post_allocation_notify(klass, (oop)obj);
86 }
87
88 void CollectedHeap::post_allocation_setup_array(KlassHandle klass,
89 HeapWord* obj,
90 size_t size,
91 int length) {
92 // Set array length before setting the _klass field
93 // in post_allocation_setup_common() because the klass field
94 // indicates that the object is parsable by concurrent GC.
95 assert(length >= 0, "length should be non-negative");
96 ((arrayOop)obj)->set_length(length);
97 post_allocation_setup_common(klass, obj, size);
98 assert(((oop)obj)->blueprint()->oop_is_array(), "must be an array");
99 // notify jvmti and dtrace (must be after length is set for dtrace)
100 post_allocation_notify(klass, (oop)obj);
101 }
102
103 HeapWord* CollectedHeap::common_mem_allocate_noinit(size_t size, bool is_noref, TRAPS) {
104
105 // Clear unhandled oops for memory allocation. Memory allocation might
106 // not take out a lock if from tlab, so clear here.
107 CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
108
109 if (HAS_PENDING_EXCEPTION) {
110 NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
111 return NULL; // caller does a CHECK_0 too
112 }
113
114 // We may want to update this, is_noref objects might not be allocated in TLABs.
115 HeapWord* result = NULL;
116 if (UseTLAB) {
117 result = CollectedHeap::allocate_from_tlab(THREAD, size);
118 if (result != NULL) {
119 assert(!HAS_PENDING_EXCEPTION,
120 "Unexpected exception, will result in uninitialized storage");
121 return result;
122 }
123 }
124 bool gc_overhead_limit_was_exceeded = false;
125 result = Universe::heap()->mem_allocate(size,
126 is_noref,
127 false,
128 &gc_overhead_limit_was_exceeded);
129 if (result != NULL) {
130 NOT_PRODUCT(Universe::heap()->
131 check_for_non_bad_heap_word_value(result, size));
132 assert(!HAS_PENDING_EXCEPTION,
133 "Unexpected exception, will result in uninitialized storage");
134 return result;
135 }
136
137
138 if (!gc_overhead_limit_was_exceeded) {
139 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
140 report_java_out_of_memory("Java heap space");
141
142 if (JvmtiExport::should_post_resource_exhausted()) {
143 JvmtiExport::post_resource_exhausted(
144 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
145 "Java heap space");
146 }
147
148 THROW_OOP_0(Universe::out_of_memory_error_java_heap());
149 } else {
150 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
151 report_java_out_of_memory("GC overhead limit exceeded");
152
153 if (JvmtiExport::should_post_resource_exhausted()) {
154 JvmtiExport::post_resource_exhausted(
155 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
156 "GC overhead limit exceeded");
157 }
158
159 THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
160 }
161 }
162
163 HeapWord* CollectedHeap::common_mem_allocate_init(size_t size, bool is_noref, TRAPS) {
164 HeapWord* obj = common_mem_allocate_noinit(size, is_noref, CHECK_NULL);
165 init_obj(obj, size);
166 return obj;
167 }
168
169 // Need to investigate, do we really want to throw OOM exception here?
170 HeapWord* CollectedHeap::common_permanent_mem_allocate_noinit(size_t size, TRAPS) {
171 if (HAS_PENDING_EXCEPTION) {
172 NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
173 return NULL; // caller does a CHECK_NULL too
174 }
175
176 #ifdef ASSERT
177 if (CIFireOOMAt > 0 && THREAD->is_Compiler_thread() &&
178 ++_fire_out_of_memory_count >= CIFireOOMAt) {
179 // For testing of OOM handling in the CI throw an OOM and see how
180 // it does. Historically improper handling of these has resulted
181 // in crashes which we really don't want to have in the CI.
182 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
183 }
184 #endif
185
186 HeapWord* result = Universe::heap()->permanent_mem_allocate(size);
187 if (result != NULL) {
188 NOT_PRODUCT(Universe::heap()->
189 check_for_non_bad_heap_word_value(result, size));
190 assert(!HAS_PENDING_EXCEPTION,
191 "Unexpected exception, will result in uninitialized storage");
192 return result;
193 }
194 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
195 report_java_out_of_memory("PermGen space");
196
197 if (JvmtiExport::should_post_resource_exhausted()) {
198 JvmtiExport::post_resource_exhausted(
199 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
200 "PermGen space");
201 }
202
203 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
204 }
205
206 HeapWord* CollectedHeap::common_permanent_mem_allocate_init(size_t size, TRAPS) {
207 HeapWord* obj = common_permanent_mem_allocate_noinit(size, CHECK_NULL);
208 init_obj(obj, size);
209 return obj;
210 }
211
212 HeapWord* CollectedHeap::allocate_from_tlab(Thread* thread, size_t size) {
213 assert(UseTLAB, "should use UseTLAB");
214
215 HeapWord* obj = thread->tlab().allocate(size);
216 if (obj != NULL) {
217 return obj;
218 }
219 // Otherwise...
220 return allocate_from_tlab_slow(thread, size);
221 }
222
223 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
224 assert(obj != NULL, "cannot initialize NULL object");
225 const size_t hs = oopDesc::header_size();
226 assert(size >= hs, "unexpected object size");
227 ((oop)obj)->set_klass_gap(0);
228 Copy::fill_to_aligned_words(obj + hs, size - hs);
229 }
230
231 oop CollectedHeap::obj_allocate(KlassHandle klass, int size, TRAPS) {
232 debug_only(check_for_valid_allocation_state());
233 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
234 assert(size >= 0, "int won't convert to size_t");
235 HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
236 post_allocation_setup_obj(klass, obj, size);
237 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
238 return (oop)obj;
239 }
240
241 oop CollectedHeap::array_allocate(KlassHandle klass,
242 int size,
243 int length,
244 TRAPS) {
245 debug_only(check_for_valid_allocation_state());
246 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
247 assert(size >= 0, "int won't convert to size_t");
248 HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
249 post_allocation_setup_array(klass, obj, size, length);
250 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
251 return (oop)obj;
252 }
253
254 oop CollectedHeap::large_typearray_allocate(KlassHandle klass,
255 int size,
256 int length,
257 TRAPS) {
258 debug_only(check_for_valid_allocation_state());
259 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
260 assert(size >= 0, "int won't convert to size_t");
261 HeapWord* obj = common_mem_allocate_init(size, true, CHECK_NULL);
262 post_allocation_setup_array(klass, obj, size, length);
263 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
264 return (oop)obj;
265 }
266
267 oop CollectedHeap::permanent_obj_allocate(KlassHandle klass, int size, TRAPS) {
268 oop obj = permanent_obj_allocate_no_klass_install(klass, size, CHECK_NULL);
269 post_allocation_install_obj_klass(klass, obj, size);
270 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value((HeapWord*) obj,
271 size));
272 return obj;
273 }
274
275 oop CollectedHeap::permanent_obj_allocate_no_klass_install(KlassHandle klass,
276 int size,
277 TRAPS) {
278 debug_only(check_for_valid_allocation_state());
279 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
280 assert(size >= 0, "int won't convert to size_t");
281 HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
282 post_allocation_setup_no_klass_install(klass, obj, size);
283 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
284 return (oop)obj;
285 }
286
287 oop CollectedHeap::permanent_array_allocate(KlassHandle klass,
288 int size,
289 int length,
290 TRAPS) {
291 debug_only(check_for_valid_allocation_state());
292 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
293 assert(size >= 0, "int won't convert to size_t");
294 HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
295 post_allocation_setup_array(klass, obj, size, length);
296 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
297 return (oop)obj;
298 }
299
300 // Returns "TRUE" if "p" is a method oop in the
301 // current heap with high probability. NOTE: The main
302 // current consumers of this interface are Forte::
303 // and ThreadProfiler::. In these cases, the
304 // interpreter frame from which "p" came, may be
305 // under construction when sampled asynchronously, so
306 // the clients want to check that it represents a
307 // valid method before using it. Nonetheless since
308 // the clients do not typically lock out GC, the
309 // predicate is_valid_method() is not stable, so
310 // it is possible that by the time "p" is used, it
311 // is no longer valid.
312 inline bool CollectedHeap::is_valid_method(oop p) const {
313 return
314 p != NULL &&
315
316 // Check whether it is aligned at a HeapWord boundary.
317 Space::is_aligned(p) &&
318
319 // Check whether "method" is in the allocated part of the
320 // permanent generation -- this needs to be checked before
321 // p->klass() below to avoid a SEGV (but see below
322 // for a potential window of vulnerability).
323 is_permanent((void*)p) &&
324
325 // See if GC is active; however, there is still an
326 // apparently unavoidable window after this call
327 // and before the client of this interface uses "p".
328 // If the client chooses not to lock out GC, then
329 // it's a risk the client must accept.
330 !is_gc_active() &&
331
332 // Check that p is a methodOop.
333 p->klass() == Universe::methodKlassObj();
334 }
335
336
337 #ifndef PRODUCT
338
339 inline bool
340 CollectedHeap::promotion_should_fail(volatile size_t* count) {
341 // Access to count is not atomic; the value does not have to be exact.
342 if (PromotionFailureALot) {
343 const size_t gc_num = total_collections();
344 const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
345 if (elapsed_gcs >= PromotionFailureALotInterval) {
346 // Test for unsigned arithmetic wrap-around.
347 if (++*count >= PromotionFailureALotCount) {
348 *count = 0;
349 return true;
350 }
351 }
352 }
353 return false;
354 }
355
356 inline bool CollectedHeap::promotion_should_fail() {
357 return promotion_should_fail(&_promotion_failure_alot_count);
358 }
359
360 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
361 if (PromotionFailureALot) {
362 _promotion_failure_alot_gc_number = total_collections();
363 *count = 0;
364 }
365 }
366
367 inline void CollectedHeap::reset_promotion_should_fail() {
368 reset_promotion_should_fail(&_promotion_failure_alot_count);
369 }
370 #endif // #ifndef PRODUCT