1 #ifdef USE_PRAGMA_IDENT_HDR
2 #pragma ident "@(#)collectedHeap.inline.hpp 1.50 07/09/07 10:56:50 JVM"
3 #endif
4 /*
5 * Copyright 2001-2008 Sun Microsystems, Inc. All Rights Reserved.
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7 *
8 * This code is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License version 2 only, as
10 * published by the Free Software Foundation.
11 *
12 * This code is distributed in the hope that it will be useful, but WITHOUT
13 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 * version 2 for more details (a copy is included in the LICENSE file that
16 * accompanied this code).
17 *
18 * You should have received a copy of the GNU General Public License version
19 * 2 along with this work; if not, write to the Free Software Foundation,
20 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
21 *
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
24 * have any questions.
25 *
26 */
27
28 // Inline allocation implementations.
29
30 void CollectedHeap::post_allocation_setup_common(KlassHandle klass,
31 HeapWord* obj,
32 size_t size) {
33 post_allocation_setup_no_klass_install(klass, obj, size);
34 post_allocation_install_obj_klass(klass, oop(obj), (int) size);
35 }
36
37 void CollectedHeap::post_allocation_setup_no_klass_install(KlassHandle klass,
38 HeapWord* objPtr,
39 size_t size) {
40 oop obj = (oop)objPtr;
41
42 assert(obj != NULL, "NULL object pointer");
43 if (UseBiasedLocking && (klass() != NULL)) {
44 obj->set_mark(klass->prototype_header());
45 } else {
46 // May be bootstrapping
47 obj->set_mark(markOopDesc::prototype());
48 }
49 }
50
51 void CollectedHeap::post_allocation_install_obj_klass(KlassHandle klass,
52 oop obj,
53 int size) {
54 // These asserts are kind of complicated because of klassKlass
55 // and the beginning of the world.
56 assert(klass() != NULL || !Universe::is_fully_initialized(), "NULL klass");
57 assert(klass() == NULL || klass()->is_klass(), "not a klass");
58 assert(klass() == NULL || klass()->klass_part() != NULL, "not a klass");
59 assert(obj != NULL, "NULL object pointer");
60 obj->set_klass(klass());
61 assert(!Universe::is_fully_initialized() || obj->blueprint() != NULL,
62 "missing blueprint");
63 }
64
65 // Support for jvmti and dtrace
66 inline void post_allocation_notify(KlassHandle klass, oop obj) {
67 // support low memory notifications (no-op if not enabled)
68 LowMemoryDetector::detect_low_memory_for_collected_pools();
69
70 // support for JVMTI VMObjectAlloc event (no-op if not enabled)
71 JvmtiExport::vm_object_alloc_event_collector(obj);
72
73 if (DTraceAllocProbes) {
74 // support for Dtrace object alloc event (no-op most of the time)
75 if (klass() != NULL && klass()->klass_part()->name() != NULL) {
76 SharedRuntime::dtrace_object_alloc(obj);
77 }
78 }
79 }
80
81 void CollectedHeap::post_allocation_setup_obj(KlassHandle klass,
82 HeapWord* obj,
83 size_t size) {
84 post_allocation_setup_common(klass, obj, size);
85 assert(Universe::is_bootstrapping() ||
86 !((oop)obj)->blueprint()->oop_is_array(), "must not be an array");
87 // notify jvmti and dtrace
88 post_allocation_notify(klass, (oop)obj);
89 }
90
91 void CollectedHeap::post_allocation_setup_array(KlassHandle klass,
92 HeapWord* obj,
93 size_t size,
94 int length) {
95 // Set array length before setting the _klass field
96 // in post_allocation_setup_common() because the klass field
97 // indicates that the object is parsable by concurrent GC.
98 assert(length >= 0, "length should be non-negative");
99 ((arrayOop)obj)->set_length(length);
100 post_allocation_setup_common(klass, obj, size);
101 assert(((oop)obj)->blueprint()->oop_is_array(), "must be an array");
102 // notify jvmti and dtrace (must be after length is set for dtrace)
103 post_allocation_notify(klass, (oop)obj);
104 }
105
106 HeapWord* CollectedHeap::common_mem_allocate_noinit(size_t size, bool is_noref, TRAPS) {
107
108 // Clear unhandled oops for memory allocation. Memory allocation might
109 // not take out a lock if from tlab, so clear here.
110 CHECK_UNHANDLED_OOPS_ONLY(THREAD->clear_unhandled_oops();)
111
112 if (HAS_PENDING_EXCEPTION) {
113 NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
114 return NULL; // caller does a CHECK_0 too
115 }
116
117 // We may want to update this, is_noref objects might not be allocated in TLABs.
118 HeapWord* result = NULL;
119 if (UseTLAB) {
120 result = CollectedHeap::allocate_from_tlab(THREAD, size);
121 if (result != NULL) {
122 assert(!HAS_PENDING_EXCEPTION,
123 "Unexpected exception, will result in uninitialized storage");
124 return result;
125 }
126 }
127 bool gc_overhead_limit_was_exceeded = false;
128 result = Universe::heap()->mem_allocate(size,
129 is_noref,
130 false,
131 &gc_overhead_limit_was_exceeded);
132 if (result != NULL) {
133 NOT_PRODUCT(Universe::heap()->
134 check_for_non_bad_heap_word_value(result, size));
135 assert(!HAS_PENDING_EXCEPTION,
136 "Unexpected exception, will result in uninitialized storage");
137 return result;
138 }
139
140
141 if (!gc_overhead_limit_was_exceeded) {
142 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
143 report_java_out_of_memory("Java heap space");
144
145 if (JvmtiExport::should_post_resource_exhausted()) {
146 JvmtiExport::post_resource_exhausted(
147 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
148 "Java heap space");
149 }
150
151 THROW_OOP_0(Universe::out_of_memory_error_java_heap());
152 } else {
153 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
154 report_java_out_of_memory("GC overhead limit exceeded");
155
156 if (JvmtiExport::should_post_resource_exhausted()) {
157 JvmtiExport::post_resource_exhausted(
158 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR | JVMTI_RESOURCE_EXHAUSTED_JAVA_HEAP,
159 "GC overhead limit exceeded");
160 }
161
162 THROW_OOP_0(Universe::out_of_memory_error_gc_overhead_limit());
163 }
164 }
165
166 HeapWord* CollectedHeap::common_mem_allocate_init(size_t size, bool is_noref, TRAPS) {
167 HeapWord* obj = common_mem_allocate_noinit(size, is_noref, CHECK_NULL);
168 init_obj(obj, size);
169 return obj;
170 }
171
172 // Need to investigate, do we really want to throw OOM exception here?
173 HeapWord* CollectedHeap::common_permanent_mem_allocate_noinit(size_t size, TRAPS) {
174 if (HAS_PENDING_EXCEPTION) {
175 NOT_PRODUCT(guarantee(false, "Should not allocate with exception pending"));
176 return NULL; // caller does a CHECK_NULL too
177 }
178
179 #ifdef ASSERT
180 if (CIFireOOMAt > 0 && THREAD->is_Compiler_thread() &&
181 ++_fire_out_of_memory_count >= CIFireOOMAt) {
182 // For testing of OOM handling in the CI throw an OOM and see how
183 // it does. Historically improper handling of these has resulted
184 // in crashes which we really don't want to have in the CI.
185 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
186 }
187 #endif
188
189 HeapWord* result = Universe::heap()->permanent_mem_allocate(size);
190 if (result != NULL) {
191 NOT_PRODUCT(Universe::heap()->
192 check_for_non_bad_heap_word_value(result, size));
193 assert(!HAS_PENDING_EXCEPTION,
194 "Unexpected exception, will result in uninitialized storage");
195 return result;
196 }
197 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
198 report_java_out_of_memory("PermGen space");
199
200 if (JvmtiExport::should_post_resource_exhausted()) {
201 JvmtiExport::post_resource_exhausted(
202 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
203 "PermGen space");
204 }
205
206 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
207 }
208
209 HeapWord* CollectedHeap::common_permanent_mem_allocate_init(size_t size, TRAPS) {
210 HeapWord* obj = common_permanent_mem_allocate_noinit(size, CHECK_NULL);
211 init_obj(obj, size);
212 return obj;
213 }
214
215 HeapWord* CollectedHeap::allocate_from_tlab(Thread* thread, size_t size) {
216 assert(UseTLAB, "should use UseTLAB");
217
218 HeapWord* obj = thread->tlab().allocate(size);
219 if (obj != NULL) {
220 return obj;
221 }
222 // Otherwise...
223 return allocate_from_tlab_slow(thread, size);
224 }
225
226 void CollectedHeap::init_obj(HeapWord* obj, size_t size) {
227 assert(obj != NULL, "cannot initialize NULL object");
228 const size_t hs = oopDesc::header_size();
229 assert(size >= hs, "unexpected object size");
230 ((oop)obj)->set_klass_gap(0);
231 Copy::fill_to_aligned_words(obj + hs, size - hs);
232 }
233
234 oop CollectedHeap::obj_allocate(KlassHandle klass, int size, TRAPS) {
235 debug_only(check_for_valid_allocation_state());
236 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
237 assert(size >= 0, "int won't convert to size_t");
238 HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
239 post_allocation_setup_obj(klass, obj, size);
240 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
241 return (oop)obj;
242 }
243
244 oop CollectedHeap::array_allocate(KlassHandle klass,
245 int size,
246 int length,
247 TRAPS) {
248 debug_only(check_for_valid_allocation_state());
249 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
250 assert(size >= 0, "int won't convert to size_t");
251 HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);
252 post_allocation_setup_array(klass, obj, size, length);
253 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
254 return (oop)obj;
255 }
256
257 oop CollectedHeap::large_typearray_allocate(KlassHandle klass,
258 int size,
259 int length,
260 TRAPS) {
261 debug_only(check_for_valid_allocation_state());
262 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
263 assert(size >= 0, "int won't convert to size_t");
264 HeapWord* obj = common_mem_allocate_init(size, true, CHECK_NULL);
265 post_allocation_setup_array(klass, obj, size, length);
266 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
267 return (oop)obj;
268 }
269
270 oop CollectedHeap::permanent_obj_allocate(KlassHandle klass, int size, TRAPS) {
271 oop obj = permanent_obj_allocate_no_klass_install(klass, size, CHECK_NULL);
272 post_allocation_install_obj_klass(klass, obj, size);
273 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value((HeapWord*) obj,
274 size));
275 return obj;
276 }
277
278 oop CollectedHeap::permanent_obj_allocate_no_klass_install(KlassHandle klass,
279 int size,
280 TRAPS) {
281 debug_only(check_for_valid_allocation_state());
282 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
283 assert(size >= 0, "int won't convert to size_t");
284 HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
285 post_allocation_setup_no_klass_install(klass, obj, size);
286 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
287 return (oop)obj;
288 }
289
290 oop CollectedHeap::permanent_array_allocate(KlassHandle klass,
291 int size,
292 int length,
293 TRAPS) {
294 debug_only(check_for_valid_allocation_state());
295 assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
296 assert(size >= 0, "int won't convert to size_t");
297 HeapWord* obj = common_permanent_mem_allocate_init(size, CHECK_NULL);
298 post_allocation_setup_array(klass, obj, size, length);
299 NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));
300 return (oop)obj;
301 }
302
303 // Returns "TRUE" if "p" is a method oop in the
304 // current heap with high probability. NOTE: The main
305 // current consumers of this interface are Forte::
306 // and ThreadProfiler::. In these cases, the
307 // interpreter frame from which "p" came, may be
308 // under construction when sampled asynchronously, so
309 // the clients want to check that it represents a
310 // valid method before using it. Nonetheless since
311 // the clients do not typically lock out GC, the
312 // predicate is_valid_method() is not stable, so
313 // it is possible that by the time "p" is used, it
314 // is no longer valid.
315 inline bool CollectedHeap::is_valid_method(oop p) const {
316 return
317 p != NULL &&
318
319 // Check whether it is aligned at a HeapWord boundary.
320 Space::is_aligned(p) &&
321
322 // Check whether "method" is in the allocated part of the
323 // permanent generation -- this needs to be checked before
324 // p->klass() below to avoid a SEGV (but see below
325 // for a potential window of vulnerability).
326 is_permanent((void*)p) &&
327
328 // See if GC is active; however, there is still an
329 // apparently unavoidable window after this call
330 // and before the client of this interface uses "p".
331 // If the client chooses not to lock out GC, then
332 // it's a risk the client must accept.
333 !is_gc_active() &&
334
335 // Check that p is a methodOop.
336 p->klass() == Universe::methodKlassObj();
337 }
338
339
340 #ifndef PRODUCT
341
342 inline bool
343 CollectedHeap::promotion_should_fail(volatile size_t* count) {
344 // Access to count is not atomic; the value does not have to be exact.
345 if (PromotionFailureALot) {
346 const size_t gc_num = total_collections();
347 const size_t elapsed_gcs = gc_num - _promotion_failure_alot_gc_number;
348 if (elapsed_gcs >= PromotionFailureALotInterval) {
349 // Test for unsigned arithmetic wrap-around.
350 if (++*count >= PromotionFailureALotCount) {
351 *count = 0;
352 return true;
353 }
354 }
355 }
356 return false;
357 }
358
359 inline bool CollectedHeap::promotion_should_fail() {
360 return promotion_should_fail(&_promotion_failure_alot_count);
361 }
362
363 inline void CollectedHeap::reset_promotion_should_fail(volatile size_t* count) {
364 if (PromotionFailureALot) {
365 _promotion_failure_alot_gc_number = total_collections();
366 *count = 0;
367 }
368 }
369
370 inline void CollectedHeap::reset_promotion_should_fail() {
371 reset_promotion_should_fail(&_promotion_failure_alot_count);
372 }
373 #endif // #ifndef PRODUCT