Fri, 23 Mar 2012 15:28:24 +0100
7103665: HeapWord*ParallelScavengeHeap::failed_mem_allocate(unsigned long,bool)+0x97
Summary: Make sure that MutableNUMASpace::ensure_parsability() only calls CollectedHeap::fill_with_object() with valid sizes and make sure CollectedHeap::filler_array_max_size() returns a value that can be converted to an int without overflow
Reviewed-by: azeemj, jmasa, iveresov
1 /*
2 * Copyright (c) 2001, 2012, 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
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7 * published by the Free Software Foundation.
8 *
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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,
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23 */
25 #ifndef SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP
26 #define SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP
28 #include "gc_interface/gcCause.hpp"
29 #include "memory/allocation.hpp"
30 #include "memory/barrierSet.hpp"
31 #include "runtime/handles.hpp"
32 #include "runtime/perfData.hpp"
33 #include "runtime/safepoint.hpp"
34 #include "utilities/events.hpp"
36 // A "CollectedHeap" is an implementation of a java heap for HotSpot. This
37 // is an abstract class: there may be many different kinds of heaps. This
38 // class defines the functions that a heap must implement, and contains
39 // infrastructure common to all heaps.
41 class BarrierSet;
42 class ThreadClosure;
43 class AdaptiveSizePolicy;
44 class Thread;
45 class CollectorPolicy;
47 class GCMessage : public FormatBuffer<1024> {
48 public:
49 bool is_before;
51 public:
52 GCMessage() {}
53 };
55 class GCHeapLog : public EventLogBase<GCMessage> {
56 private:
57 void log_heap(bool before);
59 public:
60 GCHeapLog() : EventLogBase<GCMessage>("GC Heap History") {}
62 void log_heap_before() {
63 log_heap(true);
64 }
65 void log_heap_after() {
66 log_heap(false);
67 }
68 };
70 //
71 // CollectedHeap
72 // SharedHeap
73 // GenCollectedHeap
74 // G1CollectedHeap
75 // ParallelScavengeHeap
76 //
77 class CollectedHeap : public CHeapObj {
78 friend class VMStructs;
79 friend class IsGCActiveMark; // Block structured external access to _is_gc_active
80 friend class constantPoolCacheKlass; // allocate() method inserts is_conc_safe
82 #ifdef ASSERT
83 static int _fire_out_of_memory_count;
84 #endif
86 // Used for filler objects (static, but initialized in ctor).
87 static size_t _filler_array_max_size;
89 GCHeapLog* _gc_heap_log;
91 // Used in support of ReduceInitialCardMarks; only consulted if COMPILER2 is being used
92 bool _defer_initial_card_mark;
94 protected:
95 MemRegion _reserved;
96 BarrierSet* _barrier_set;
97 bool _is_gc_active;
98 uint _n_par_threads;
100 unsigned int _total_collections; // ... started
101 unsigned int _total_full_collections; // ... started
102 NOT_PRODUCT(volatile size_t _promotion_failure_alot_count;)
103 NOT_PRODUCT(volatile size_t _promotion_failure_alot_gc_number;)
105 // Reason for current garbage collection. Should be set to
106 // a value reflecting no collection between collections.
107 GCCause::Cause _gc_cause;
108 GCCause::Cause _gc_lastcause;
109 PerfStringVariable* _perf_gc_cause;
110 PerfStringVariable* _perf_gc_lastcause;
112 // Constructor
113 CollectedHeap();
115 // Do common initializations that must follow instance construction,
116 // for example, those needing virtual calls.
117 // This code could perhaps be moved into initialize() but would
118 // be slightly more awkward because we want the latter to be a
119 // pure virtual.
120 void pre_initialize();
122 // Create a new tlab. All TLAB allocations must go through this.
123 virtual HeapWord* allocate_new_tlab(size_t size);
125 // Accumulate statistics on all tlabs.
126 virtual void accumulate_statistics_all_tlabs();
128 // Reinitialize tlabs before resuming mutators.
129 virtual void resize_all_tlabs();
131 // Allocate from the current thread's TLAB, with broken-out slow path.
132 inline static HeapWord* allocate_from_tlab(Thread* thread, size_t size);
133 static HeapWord* allocate_from_tlab_slow(Thread* thread, size_t size);
135 // Allocate an uninitialized block of the given size, or returns NULL if
136 // this is impossible.
137 inline static HeapWord* common_mem_allocate_noinit(size_t size, TRAPS);
139 // Like allocate_init, but the block returned by a successful allocation
140 // is guaranteed initialized to zeros.
141 inline static HeapWord* common_mem_allocate_init(size_t size, TRAPS);
143 // Same as common_mem version, except memory is allocated in the permanent area
144 // If there is no permanent area, revert to common_mem_allocate_noinit
145 inline static HeapWord* common_permanent_mem_allocate_noinit(size_t size, TRAPS);
147 // Same as common_mem version, except memory is allocated in the permanent area
148 // If there is no permanent area, revert to common_mem_allocate_init
149 inline static HeapWord* common_permanent_mem_allocate_init(size_t size, TRAPS);
151 // Helper functions for (VM) allocation.
152 inline static void post_allocation_setup_common(KlassHandle klass,
153 HeapWord* obj, size_t size);
154 inline static void post_allocation_setup_no_klass_install(KlassHandle klass,
155 HeapWord* objPtr,
156 size_t size);
158 inline static void post_allocation_setup_obj(KlassHandle klass,
159 HeapWord* obj, size_t size);
161 inline static void post_allocation_setup_array(KlassHandle klass,
162 HeapWord* obj, size_t size,
163 int length);
165 // Clears an allocated object.
166 inline static void init_obj(HeapWord* obj, size_t size);
168 // Filler object utilities.
169 static inline size_t filler_array_hdr_size();
170 static inline size_t filler_array_min_size();
172 DEBUG_ONLY(static void fill_args_check(HeapWord* start, size_t words);)
173 DEBUG_ONLY(static void zap_filler_array(HeapWord* start, size_t words, bool zap = true);)
175 // Fill with a single array; caller must ensure filler_array_min_size() <=
176 // words <= filler_array_max_size().
177 static inline void fill_with_array(HeapWord* start, size_t words, bool zap = true);
179 // Fill with a single object (either an int array or a java.lang.Object).
180 static inline void fill_with_object_impl(HeapWord* start, size_t words, bool zap = true);
182 // Verification functions
183 virtual void check_for_bad_heap_word_value(HeapWord* addr, size_t size)
184 PRODUCT_RETURN;
185 virtual void check_for_non_bad_heap_word_value(HeapWord* addr, size_t size)
186 PRODUCT_RETURN;
187 debug_only(static void check_for_valid_allocation_state();)
189 public:
190 enum Name {
191 Abstract,
192 SharedHeap,
193 GenCollectedHeap,
194 ParallelScavengeHeap,
195 G1CollectedHeap
196 };
198 static inline size_t filler_array_max_size() {
199 return _filler_array_max_size;
200 }
202 virtual CollectedHeap::Name kind() const { return CollectedHeap::Abstract; }
204 /**
205 * Returns JNI error code JNI_ENOMEM if memory could not be allocated,
206 * and JNI_OK on success.
207 */
208 virtual jint initialize() = 0;
210 // In many heaps, there will be a need to perform some initialization activities
211 // after the Universe is fully formed, but before general heap allocation is allowed.
212 // This is the correct place to place such initialization methods.
213 virtual void post_initialize() = 0;
215 MemRegion reserved_region() const { return _reserved; }
216 address base() const { return (address)reserved_region().start(); }
218 // Future cleanup here. The following functions should specify bytes or
219 // heapwords as part of their signature.
220 virtual size_t capacity() const = 0;
221 virtual size_t used() const = 0;
223 // Return "true" if the part of the heap that allocates Java
224 // objects has reached the maximal committed limit that it can
225 // reach, without a garbage collection.
226 virtual bool is_maximal_no_gc() const = 0;
228 virtual size_t permanent_capacity() const = 0;
229 virtual size_t permanent_used() const = 0;
231 // Support for java.lang.Runtime.maxMemory(): return the maximum amount of
232 // memory that the vm could make available for storing 'normal' java objects.
233 // This is based on the reserved address space, but should not include space
234 // that the vm uses internally for bookkeeping or temporary storage (e.g.,
235 // perm gen space or, in the case of the young gen, one of the survivor
236 // spaces).
237 virtual size_t max_capacity() const = 0;
239 // Returns "TRUE" if "p" points into the reserved area of the heap.
240 bool is_in_reserved(const void* p) const {
241 return _reserved.contains(p);
242 }
244 bool is_in_reserved_or_null(const void* p) const {
245 return p == NULL || is_in_reserved(p);
246 }
248 // Returns "TRUE" iff "p" points into the committed areas of the heap.
249 // Since this method can be expensive in general, we restrict its
250 // use to assertion checking only.
251 virtual bool is_in(const void* p) const = 0;
253 bool is_in_or_null(const void* p) const {
254 return p == NULL || is_in(p);
255 }
257 // Let's define some terms: a "closed" subset of a heap is one that
258 //
259 // 1) contains all currently-allocated objects, and
260 //
261 // 2) is closed under reference: no object in the closed subset
262 // references one outside the closed subset.
263 //
264 // Membership in a heap's closed subset is useful for assertions.
265 // Clearly, the entire heap is a closed subset, so the default
266 // implementation is to use "is_in_reserved". But this may not be too
267 // liberal to perform useful checking. Also, the "is_in" predicate
268 // defines a closed subset, but may be too expensive, since "is_in"
269 // verifies that its argument points to an object head. The
270 // "closed_subset" method allows a heap to define an intermediate
271 // predicate, allowing more precise checking than "is_in_reserved" at
272 // lower cost than "is_in."
274 // One important case is a heap composed of disjoint contiguous spaces,
275 // such as the Garbage-First collector. Such heaps have a convenient
276 // closed subset consisting of the allocated portions of those
277 // contiguous spaces.
279 // Return "TRUE" iff the given pointer points into the heap's defined
280 // closed subset (which defaults to the entire heap).
281 virtual bool is_in_closed_subset(const void* p) const {
282 return is_in_reserved(p);
283 }
285 bool is_in_closed_subset_or_null(const void* p) const {
286 return p == NULL || is_in_closed_subset(p);
287 }
289 // XXX is_permanent() and is_in_permanent() should be better named
290 // to distinguish one from the other.
292 // Returns "TRUE" if "p" is allocated as "permanent" data.
293 // If the heap does not use "permanent" data, returns the same
294 // value is_in_reserved() would return.
295 // NOTE: this actually returns true if "p" is in reserved space
296 // for the space not that it is actually allocated (i.e. in committed
297 // space). If you need the more conservative answer use is_permanent().
298 virtual bool is_in_permanent(const void *p) const = 0;
301 #ifdef ASSERT
302 // Returns true if "p" is in the part of the
303 // heap being collected.
304 virtual bool is_in_partial_collection(const void *p) = 0;
305 #endif
307 bool is_in_permanent_or_null(const void *p) const {
308 return p == NULL || is_in_permanent(p);
309 }
311 // Returns "TRUE" if "p" is in the committed area of "permanent" data.
312 // If the heap does not use "permanent" data, returns the same
313 // value is_in() would return.
314 virtual bool is_permanent(const void *p) const = 0;
316 bool is_permanent_or_null(const void *p) const {
317 return p == NULL || is_permanent(p);
318 }
320 // An object is scavengable if its location may move during a scavenge.
321 // (A scavenge is a GC which is not a full GC.)
322 virtual bool is_scavengable(const void *p) = 0;
324 // Returns "TRUE" if "p" is a method oop in the
325 // current heap, with high probability. This predicate
326 // is not stable, in general.
327 bool is_valid_method(oop p) const;
329 void set_gc_cause(GCCause::Cause v) {
330 if (UsePerfData) {
331 _gc_lastcause = _gc_cause;
332 _perf_gc_lastcause->set_value(GCCause::to_string(_gc_lastcause));
333 _perf_gc_cause->set_value(GCCause::to_string(v));
334 }
335 _gc_cause = v;
336 }
337 GCCause::Cause gc_cause() { return _gc_cause; }
339 // Number of threads currently working on GC tasks.
340 uint n_par_threads() { return _n_par_threads; }
342 // May be overridden to set additional parallelism.
343 virtual void set_par_threads(uint t) { _n_par_threads = t; };
345 // Preload classes into the shared portion of the heap, and then dump
346 // that data to a file so that it can be loaded directly by another
347 // VM (then terminate).
348 virtual void preload_and_dump(TRAPS) { ShouldNotReachHere(); }
350 // Allocate and initialize instances of Class
351 static oop Class_obj_allocate(KlassHandle klass, int size, KlassHandle real_klass, TRAPS);
353 // General obj/array allocation facilities.
354 inline static oop obj_allocate(KlassHandle klass, int size, TRAPS);
355 inline static oop array_allocate(KlassHandle klass, int size, int length, TRAPS);
356 inline static oop array_allocate_nozero(KlassHandle klass, int size, int length, TRAPS);
358 // Special obj/array allocation facilities.
359 // Some heaps may want to manage "permanent" data uniquely. These default
360 // to the general routines if the heap does not support such handling.
361 inline static oop permanent_obj_allocate(KlassHandle klass, int size, TRAPS);
362 // permanent_obj_allocate_no_klass_install() does not do the installation of
363 // the klass pointer in the newly created object (as permanent_obj_allocate()
364 // above does). This allows for a delay in the installation of the klass
365 // pointer that is needed during the create of klassKlass's. The
366 // method post_allocation_install_obj_klass() is used to install the
367 // klass pointer.
368 inline static oop permanent_obj_allocate_no_klass_install(KlassHandle klass,
369 int size,
370 TRAPS);
371 inline static void post_allocation_install_obj_klass(KlassHandle klass,
372 oop obj,
373 int size);
374 inline static oop permanent_array_allocate(KlassHandle klass, int size, int length, TRAPS);
376 // Raw memory allocation facilities
377 // The obj and array allocate methods are covers for these methods.
378 // The permanent allocation method should default to mem_allocate if
379 // permanent memory isn't supported. mem_allocate() should never be
380 // called to allocate TLABs, only individual objects.
381 virtual HeapWord* mem_allocate(size_t size,
382 bool* gc_overhead_limit_was_exceeded) = 0;
383 virtual HeapWord* permanent_mem_allocate(size_t size) = 0;
385 // Utilities for turning raw memory into filler objects.
386 //
387 // min_fill_size() is the smallest region that can be filled.
388 // fill_with_objects() can fill arbitrary-sized regions of the heap using
389 // multiple objects. fill_with_object() is for regions known to be smaller
390 // than the largest array of integers; it uses a single object to fill the
391 // region and has slightly less overhead.
392 static size_t min_fill_size() {
393 return size_t(align_object_size(oopDesc::header_size()));
394 }
396 static void fill_with_objects(HeapWord* start, size_t words, bool zap = true);
398 static void fill_with_object(HeapWord* start, size_t words, bool zap = true);
399 static void fill_with_object(MemRegion region, bool zap = true) {
400 fill_with_object(region.start(), region.word_size(), zap);
401 }
402 static void fill_with_object(HeapWord* start, HeapWord* end, bool zap = true) {
403 fill_with_object(start, pointer_delta(end, start), zap);
404 }
406 // Some heaps may offer a contiguous region for shared non-blocking
407 // allocation, via inlined code (by exporting the address of the top and
408 // end fields defining the extent of the contiguous allocation region.)
410 // This function returns "true" iff the heap supports this kind of
411 // allocation. (Default is "no".)
412 virtual bool supports_inline_contig_alloc() const {
413 return false;
414 }
415 // These functions return the addresses of the fields that define the
416 // boundaries of the contiguous allocation area. (These fields should be
417 // physically near to one another.)
418 virtual HeapWord** top_addr() const {
419 guarantee(false, "inline contiguous allocation not supported");
420 return NULL;
421 }
422 virtual HeapWord** end_addr() const {
423 guarantee(false, "inline contiguous allocation not supported");
424 return NULL;
425 }
427 // Some heaps may be in an unparseable state at certain times between
428 // collections. This may be necessary for efficient implementation of
429 // certain allocation-related activities. Calling this function before
430 // attempting to parse a heap ensures that the heap is in a parsable
431 // state (provided other concurrent activity does not introduce
432 // unparsability). It is normally expected, therefore, that this
433 // method is invoked with the world stopped.
434 // NOTE: if you override this method, make sure you call
435 // super::ensure_parsability so that the non-generational
436 // part of the work gets done. See implementation of
437 // CollectedHeap::ensure_parsability and, for instance,
438 // that of GenCollectedHeap::ensure_parsability().
439 // The argument "retire_tlabs" controls whether existing TLABs
440 // are merely filled or also retired, thus preventing further
441 // allocation from them and necessitating allocation of new TLABs.
442 virtual void ensure_parsability(bool retire_tlabs);
444 // Return an estimate of the maximum allocation that could be performed
445 // without triggering any collection or expansion activity. In a
446 // generational collector, for example, this is probably the largest
447 // allocation that could be supported (without expansion) in the youngest
448 // generation. It is "unsafe" because no locks are taken; the result
449 // should be treated as an approximation, not a guarantee, for use in
450 // heuristic resizing decisions.
451 virtual size_t unsafe_max_alloc() = 0;
453 // Section on thread-local allocation buffers (TLABs)
454 // If the heap supports thread-local allocation buffers, it should override
455 // the following methods:
456 // Returns "true" iff the heap supports thread-local allocation buffers.
457 // The default is "no".
458 virtual bool supports_tlab_allocation() const {
459 return false;
460 }
461 // The amount of space available for thread-local allocation buffers.
462 virtual size_t tlab_capacity(Thread *thr) const {
463 guarantee(false, "thread-local allocation buffers not supported");
464 return 0;
465 }
466 // An estimate of the maximum allocation that could be performed
467 // for thread-local allocation buffers without triggering any
468 // collection or expansion activity.
469 virtual size_t unsafe_max_tlab_alloc(Thread *thr) const {
470 guarantee(false, "thread-local allocation buffers not supported");
471 return 0;
472 }
474 // Can a compiler initialize a new object without store barriers?
475 // This permission only extends from the creation of a new object
476 // via a TLAB up to the first subsequent safepoint. If such permission
477 // is granted for this heap type, the compiler promises to call
478 // defer_store_barrier() below on any slow path allocation of
479 // a new object for which such initializing store barriers will
480 // have been elided.
481 virtual bool can_elide_tlab_store_barriers() const = 0;
483 // If a compiler is eliding store barriers for TLAB-allocated objects,
484 // there is probably a corresponding slow path which can produce
485 // an object allocated anywhere. The compiler's runtime support
486 // promises to call this function on such a slow-path-allocated
487 // object before performing initializations that have elided
488 // store barriers. Returns new_obj, or maybe a safer copy thereof.
489 virtual oop new_store_pre_barrier(JavaThread* thread, oop new_obj);
491 // Answers whether an initializing store to a new object currently
492 // allocated at the given address doesn't need a store
493 // barrier. Returns "true" if it doesn't need an initializing
494 // store barrier; answers "false" if it does.
495 virtual bool can_elide_initializing_store_barrier(oop new_obj) = 0;
497 // If a compiler is eliding store barriers for TLAB-allocated objects,
498 // we will be informed of a slow-path allocation by a call
499 // to new_store_pre_barrier() above. Such a call precedes the
500 // initialization of the object itself, and no post-store-barriers will
501 // be issued. Some heap types require that the barrier strictly follows
502 // the initializing stores. (This is currently implemented by deferring the
503 // barrier until the next slow-path allocation or gc-related safepoint.)
504 // This interface answers whether a particular heap type needs the card
505 // mark to be thus strictly sequenced after the stores.
506 virtual bool card_mark_must_follow_store() const = 0;
508 // If the CollectedHeap was asked to defer a store barrier above,
509 // this informs it to flush such a deferred store barrier to the
510 // remembered set.
511 virtual void flush_deferred_store_barrier(JavaThread* thread);
513 // Can a compiler elide a store barrier when it writes
514 // a permanent oop into the heap? Applies when the compiler
515 // is storing x to the heap, where x->is_perm() is true.
516 virtual bool can_elide_permanent_oop_store_barriers() const = 0;
518 // Does this heap support heap inspection (+PrintClassHistogram?)
519 virtual bool supports_heap_inspection() const = 0;
521 // Perform a collection of the heap; intended for use in implementing
522 // "System.gc". This probably implies as full a collection as the
523 // "CollectedHeap" supports.
524 virtual void collect(GCCause::Cause cause) = 0;
526 // This interface assumes that it's being called by the
527 // vm thread. It collects the heap assuming that the
528 // heap lock is already held and that we are executing in
529 // the context of the vm thread.
530 virtual void collect_as_vm_thread(GCCause::Cause cause) = 0;
532 // Returns the barrier set for this heap
533 BarrierSet* barrier_set() { return _barrier_set; }
535 // Returns "true" iff there is a stop-world GC in progress. (I assume
536 // that it should answer "false" for the concurrent part of a concurrent
537 // collector -- dld).
538 bool is_gc_active() const { return _is_gc_active; }
540 // Total number of GC collections (started)
541 unsigned int total_collections() const { return _total_collections; }
542 unsigned int total_full_collections() const { return _total_full_collections;}
544 // Increment total number of GC collections (started)
545 // Should be protected but used by PSMarkSweep - cleanup for 1.4.2
546 void increment_total_collections(bool full = false) {
547 _total_collections++;
548 if (full) {
549 increment_total_full_collections();
550 }
551 }
553 void increment_total_full_collections() { _total_full_collections++; }
555 // Return the AdaptiveSizePolicy for the heap.
556 virtual AdaptiveSizePolicy* size_policy() = 0;
558 // Return the CollectorPolicy for the heap
559 virtual CollectorPolicy* collector_policy() const = 0;
561 // Iterate over all the ref-containing fields of all objects, calling
562 // "cl.do_oop" on each. This includes objects in permanent memory.
563 virtual void oop_iterate(OopClosure* cl) = 0;
565 // Iterate over all objects, calling "cl.do_object" on each.
566 // This includes objects in permanent memory.
567 virtual void object_iterate(ObjectClosure* cl) = 0;
569 // Similar to object_iterate() except iterates only
570 // over live objects.
571 virtual void safe_object_iterate(ObjectClosure* cl) = 0;
573 // Behaves the same as oop_iterate, except only traverses
574 // interior pointers contained in permanent memory. If there
575 // is no permanent memory, does nothing.
576 virtual void permanent_oop_iterate(OopClosure* cl) = 0;
578 // Behaves the same as object_iterate, except only traverses
579 // object contained in permanent memory. If there is no
580 // permanent memory, does nothing.
581 virtual void permanent_object_iterate(ObjectClosure* cl) = 0;
583 // NOTE! There is no requirement that a collector implement these
584 // functions.
585 //
586 // A CollectedHeap is divided into a dense sequence of "blocks"; that is,
587 // each address in the (reserved) heap is a member of exactly
588 // one block. The defining characteristic of a block is that it is
589 // possible to find its size, and thus to progress forward to the next
590 // block. (Blocks may be of different sizes.) Thus, blocks may
591 // represent Java objects, or they might be free blocks in a
592 // free-list-based heap (or subheap), as long as the two kinds are
593 // distinguishable and the size of each is determinable.
595 // Returns the address of the start of the "block" that contains the
596 // address "addr". We say "blocks" instead of "object" since some heaps
597 // may not pack objects densely; a chunk may either be an object or a
598 // non-object.
599 virtual HeapWord* block_start(const void* addr) const = 0;
601 // Requires "addr" to be the start of a chunk, and returns its size.
602 // "addr + size" is required to be the start of a new chunk, or the end
603 // of the active area of the heap.
604 virtual size_t block_size(const HeapWord* addr) const = 0;
606 // Requires "addr" to be the start of a block, and returns "TRUE" iff
607 // the block is an object.
608 virtual bool block_is_obj(const HeapWord* addr) const = 0;
610 // Returns the longest time (in ms) that has elapsed since the last
611 // time that any part of the heap was examined by a garbage collection.
612 virtual jlong millis_since_last_gc() = 0;
614 // Perform any cleanup actions necessary before allowing a verification.
615 virtual void prepare_for_verify() = 0;
617 // Generate any dumps preceding or following a full gc
618 void pre_full_gc_dump();
619 void post_full_gc_dump();
621 // Print heap information on the given outputStream.
622 virtual void print_on(outputStream* st) const = 0;
623 // The default behavior is to call print_on() on tty.
624 virtual void print() const {
625 print_on(tty);
626 }
627 // Print more detailed heap information on the given
628 // outputStream. The default behaviour is to call print_on(). It is
629 // up to each subclass to override it and add any additional output
630 // it needs.
631 virtual void print_extended_on(outputStream* st) const {
632 print_on(st);
633 }
635 // Print all GC threads (other than the VM thread)
636 // used by this heap.
637 virtual void print_gc_threads_on(outputStream* st) const = 0;
638 // The default behavior is to call print_gc_threads_on() on tty.
639 void print_gc_threads() {
640 print_gc_threads_on(tty);
641 }
642 // Iterator for all GC threads (other than VM thread)
643 virtual void gc_threads_do(ThreadClosure* tc) const = 0;
645 // Print any relevant tracing info that flags imply.
646 // Default implementation does nothing.
647 virtual void print_tracing_info() const = 0;
649 // If PrintHeapAtGC is set call the appropriate routi
650 void print_heap_before_gc() {
651 if (PrintHeapAtGC) {
652 Universe::print_heap_before_gc();
653 }
654 if (_gc_heap_log != NULL) {
655 _gc_heap_log->log_heap_before();
656 }
657 }
658 void print_heap_after_gc() {
659 if (PrintHeapAtGC) {
660 Universe::print_heap_after_gc();
661 }
662 if (_gc_heap_log != NULL) {
663 _gc_heap_log->log_heap_after();
664 }
665 }
667 // Allocate GCHeapLog during VM startup
668 static void initialize_heap_log();
670 // Heap verification
671 virtual void verify(bool allow_dirty, bool silent, VerifyOption option) = 0;
673 // Non product verification and debugging.
674 #ifndef PRODUCT
675 // Support for PromotionFailureALot. Return true if it's time to cause a
676 // promotion failure. The no-argument version uses
677 // this->_promotion_failure_alot_count as the counter.
678 inline bool promotion_should_fail(volatile size_t* count);
679 inline bool promotion_should_fail();
681 // Reset the PromotionFailureALot counters. Should be called at the end of a
682 // GC in which promotion failure ocurred.
683 inline void reset_promotion_should_fail(volatile size_t* count);
684 inline void reset_promotion_should_fail();
685 #endif // #ifndef PRODUCT
687 #ifdef ASSERT
688 static int fired_fake_oom() {
689 return (CIFireOOMAt > 1 && _fire_out_of_memory_count >= CIFireOOMAt);
690 }
691 #endif
693 public:
694 // This is a convenience method that is used in cases where
695 // the actual number of GC worker threads is not pertinent but
696 // only whether there more than 0. Use of this method helps
697 // reduce the occurrence of ParallelGCThreads to uses where the
698 // actual number may be germane.
699 static bool use_parallel_gc_threads() { return ParallelGCThreads > 0; }
701 /////////////// Unit tests ///////////////
703 NOT_PRODUCT(static void test_is_in();)
704 };
706 // Class to set and reset the GC cause for a CollectedHeap.
708 class GCCauseSetter : StackObj {
709 CollectedHeap* _heap;
710 GCCause::Cause _previous_cause;
711 public:
712 GCCauseSetter(CollectedHeap* heap, GCCause::Cause cause) {
713 assert(SafepointSynchronize::is_at_safepoint(),
714 "This method manipulates heap state without locking");
715 _heap = heap;
716 _previous_cause = _heap->gc_cause();
717 _heap->set_gc_cause(cause);
718 }
720 ~GCCauseSetter() {
721 assert(SafepointSynchronize::is_at_safepoint(),
722 "This method manipulates heap state without locking");
723 _heap->set_gc_cause(_previous_cause);
724 }
725 };
727 #endif // SHARE_VM_GC_INTERFACE_COLLECTEDHEAP_HPP