Tue, 11 Sep 2012 14:59:23 +0200
7197350: NPG: jvmtiHeapReferenceCallback receives incorrect reference_kind for system class roots
Summary: Fix the iteration over the system classes and report the correct reference kind.
Reviewed-by: coleenp, rbackman
1 /*
2 * Copyright (c) 2011, 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
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
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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,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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20 * or visit www.oracle.com if you need additional information or have any
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23 */
24 #include "precompiled.hpp"
25 #include "gc_interface/collectedHeap.hpp"
26 #include "memory/binaryTreeDictionary.hpp"
27 #include "memory/collectorPolicy.hpp"
28 #include "memory/filemap.hpp"
29 #include "memory/freeList.hpp"
30 #include "memory/metaspace.hpp"
31 #include "memory/metaspaceShared.hpp"
32 #include "memory/resourceArea.hpp"
33 #include "memory/universe.hpp"
34 #include "runtime/globals.hpp"
35 #include "runtime/mutex.hpp"
36 #include "services/memTracker.hpp"
37 #include "utilities/copy.hpp"
38 #include "utilities/debug.hpp"
40 // Define this macro to deallocate Metablock. If not defined,
41 // blocks are not yet deallocated and are only mangled.
42 #undef DEALLOCATE_BLOCKS
44 // Easily recognizable patterns
45 // These patterns can be the same in 32bit or 64bit since
46 // they only have to be easily recognizable.
47 const void* metaspace_allocation_leader = (void*) 0X11111111;
48 const void* metaspace_allocation_trailer = (void*) 0X77777777;
50 // Parameters for stress mode testing
51 const uint metadata_deallocate_a_lot_block = 10;
52 const uint metadata_deallocate_a_lock_chunk = 3;
53 size_t const allocation_from_dictionary_limit = 64 * K;
54 const size_t metadata_chunk_initialize = 0xf7f7f7f7;
55 const size_t metadata_deallocate = 0xf5f5f5f5;
56 const size_t metadata_space_manager_allocate = 0xf3f3f3f3;
58 MetaWord* last_allocated = 0;
60 // Used in declarations in SpaceManager and ChunkManager
61 enum ChunkIndex {
62 SmallIndex = 0,
63 MediumIndex = 1,
64 HumongousIndex = 2,
65 NumberOfFreeLists = 3
66 };
68 static ChunkIndex next_chunk_index(ChunkIndex i) {
69 assert(i < NumberOfFreeLists, "Out of bound");
70 return (ChunkIndex) (i+1);
71 }
73 // Originally _capacity_until_GC was set to MetaspaceSize here but
74 // the default MetaspaceSize before argument processing was being
75 // used which was not the desired value. See the code
76 // in should_expand() to see how the initialization is handled
77 // now.
78 size_t MetaspaceGC::_capacity_until_GC = 0;
79 bool MetaspaceGC::_expand_after_GC = false;
80 uint MetaspaceGC::_shrink_factor = 0;
81 bool MetaspaceGC::_should_concurrent_collect = false;
83 // Blocks of space for metadata are allocated out of Metachunks.
84 //
85 // Metachunk are allocated out of MetadataVirtualspaces and once
86 // allocated there is no explicit link between a Metachunk and
87 // the MetadataVirtualspaces from which it was allocated.
88 //
89 // Each SpaceManager maintains a
90 // list of the chunks it is using and the current chunk. The current
91 // chunk is the chunk from which allocations are done. Space freed in
92 // a chunk is placed on the free list of blocks (BlockFreelist) and
93 // reused from there.
94 //
95 // Future modification
96 //
97 // The Metachunk can conceivable be replaced by the Chunk in
98 // allocation.hpp. Note that the latter Chunk is the space for
99 // allocation (allocations from the chunk are out of the space in
100 // the Chunk after the header for the Chunk) where as Metachunks
101 // point to space in a VirtualSpace. To replace Metachunks with
102 // Chunks, change Chunks so that they can be allocated out of a VirtualSpace.
103 //
105 // Metablock are the unit of allocation from a Chunk. It contains
106 // the size of the requested allocation in a debug build.
107 // Also in a debug build it has a marker before and after the
108 // body of the block. The address of the body is the address returned
109 // by the allocation.
110 //
111 // Layout in a debug build. In a product build only the body is present.
112 //
113 // +-----------+-----------+------------+ +-----------+
114 // | word size | leader | body | ... | trailer |
115 // +-----------+-----------+------------+ +-----------+
116 //
117 // A Metablock may be reused by its SpaceManager but are never moved between
118 // SpaceManagers. There is no explicit link to the Metachunk
119 // from which it was allocated. Metablock are not deallocated, rather
120 // the Metachunk it is a part of will be deallocated when it's
121 // associated class loader is collected.
122 //
123 // When the word size of a block is passed in to the deallocation
124 // call the word size no longer needs to be part of a Metablock.
126 class Metablock {
127 friend class VMStructs;
128 private:
129 // Used to align the allocation (see below) and for debugging.
130 #ifdef ASSERT
131 struct {
132 size_t _word_size;
133 void* _leader;
134 } _header;
135 void* _data[1];
136 #endif
137 static size_t _overhead;
139 #ifdef ASSERT
140 void set_word_size(size_t v) { _header._word_size = v; }
141 void* leader() { return _header._leader; }
142 void* trailer() {
143 jlong index = (jlong) _header._word_size - sizeof(_header)/BytesPerWord - 1;
144 assert(index > 0, err_msg("Bad indexling of trailer %d", index));
145 void** ptr = &_data[index];
146 return *ptr;
147 }
148 void set_leader(void* v) { _header._leader = v; }
149 void set_trailer(void* v) {
150 void** ptr = &_data[_header._word_size - sizeof(_header)/BytesPerWord - 1];
151 *ptr = v;
152 }
153 public:
154 size_t word_size() { return _header._word_size; }
155 #endif
156 public:
158 static Metablock* initialize(MetaWord* p, size_t word_size);
160 // This places the body of the block at a 2 word boundary
161 // because every block starts on a 2 word boundary. Work out
162 // how to make the body on a 2 word boundary if the block
163 // starts on a arbitrary boundary. JJJ
165 #ifdef ASSERT
166 MetaWord* data() { return (MetaWord*) &_data[0]; }
167 #else
168 MetaWord* data() { return (MetaWord*) this; }
169 #endif
170 static Metablock* metablock_from_data(MetaWord* p) {
171 #ifdef ASSERT
172 size_t word_offset = offset_of(Metablock, _data)/BytesPerWord;
173 Metablock* result = (Metablock*) (p - word_offset);
174 return result;
175 #else
176 return (Metablock*) p;
177 #endif
178 }
180 static size_t overhead() { return _overhead; }
181 void verify();
182 };
184 // Metachunk - Quantum of allocation from a Virtualspace
185 // Metachunks are reused (when freed are put on a global freelist) and
186 // have no permanent association to a SpaceManager.
188 // +--------------+ <- end
189 // | | --+ ---+
190 // | | | free |
191 // | | | |
192 // | | | | capacity
193 // | | | |
194 // | | <- top --+ |
195 // | | ---+ |
196 // | | | used |
197 // | | | |
198 // | | | |
199 // +--------------+ <- bottom ---+ ---+
201 class Metachunk VALUE_OBJ_CLASS_SPEC {
202 // link to support lists of chunks
203 Metachunk* _next;
205 MetaWord* _bottom;
206 MetaWord* _end;
207 MetaWord* _top;
208 size_t _word_size;
210 // Metachunks are allocated out of a MetadataVirtualSpace and
211 // and use some of its space to describe itself (plus alignment
212 // considerations). Metadata is allocated in the rest of the chunk.
213 // This size is the overhead of maintaining the Metachunk within
214 // the space.
215 static size_t _overhead;
217 void set_bottom(MetaWord* v) { _bottom = v; }
218 void set_end(MetaWord* v) { _end = v; }
219 void set_top(MetaWord* v) { _top = v; }
220 void set_word_size(size_t v) { _word_size = v; }
221 public:
223 // Used to add a Metachunk to a list of Metachunks
224 void set_next(Metachunk* v) { _next = v; assert(v != this, "Boom");}
226 Metablock* allocate(size_t word_size);
227 static Metachunk* initialize(MetaWord* ptr, size_t word_size);
229 // Accessors
230 Metachunk* next() const { return _next; }
231 MetaWord* bottom() const { return _bottom; }
232 MetaWord* end() const { return _end; }
233 MetaWord* top() const { return _top; }
234 size_t word_size() const { return _word_size; }
235 static size_t overhead() { return _overhead; }
237 // Reset top to bottom so chunk can be reused.
238 void reset_empty() { _top = (_bottom + _overhead); }
239 bool is_empty() { return _top == (_bottom + _overhead); }
241 // used (has been allocated)
242 // free (available for future allocations)
243 // capacity (total size of chunk)
244 size_t used_word_size();
245 size_t free_word_size();
246 size_t capacity_word_size();
248 #ifdef ASSERT
249 void mangle() {
250 // Mangle the payload of the chunk and not the links that
251 // maintain list of chunks.
252 HeapWord* start = (HeapWord*)(bottom() + overhead());
253 size_t word_size = capacity_word_size() - overhead();
254 Copy::fill_to_words(start, word_size, metadata_chunk_initialize);
255 }
256 #endif // ASSERT
258 void print_on(outputStream* st) const;
259 void verify();
260 };
263 // Pointer to list of Metachunks.
264 class ChunkList VALUE_OBJ_CLASS_SPEC {
265 // List of free chunks
266 Metachunk* _head;
268 public:
269 // Constructor
270 ChunkList() : _head(NULL) {}
272 // Accessors
273 Metachunk* head() { return _head; }
274 void set_head(Metachunk* v) { _head = v; }
276 // Link at head of the list
277 void add_at_head(Metachunk* head, Metachunk* tail);
278 void add_at_head(Metachunk* head);
280 size_t sum_list_size();
281 size_t sum_list_count();
282 size_t sum_list_capacity();
283 };
285 // Manages the global free lists of chunks.
286 // Has three lists of free chunks, and a total size and
287 // count that includes all three
289 class ChunkManager VALUE_OBJ_CLASS_SPEC {
291 // Free list of chunks of different sizes.
292 // SmallChunk
293 // MediumChunk
294 // HumongousChunk
295 ChunkList _free_chunks[3];
297 // ChunkManager in all lists of this type
298 size_t _free_chunks_total;
299 size_t _free_chunks_count;
301 void dec_free_chunks_total(size_t v) {
302 assert(_free_chunks_count > 0 &&
303 _free_chunks_total > 0,
304 "About to go negative");
305 Atomic::add_ptr(-1, &_free_chunks_count);
306 jlong minus_v = (jlong) - (jlong) v;
307 Atomic::add_ptr(minus_v, &_free_chunks_total);
308 }
310 // Debug support
312 size_t sum_free_chunks();
313 size_t sum_free_chunks_count();
315 void locked_verify_free_chunks_total();
316 void locked_verify_free_chunks_count();
317 void verify_free_chunks_count();
319 public:
321 ChunkManager() : _free_chunks_total(0), _free_chunks_count(0) {}
323 // add or delete (return) a chunk to the global freelist.
324 Metachunk* chunk_freelist_allocate(size_t word_size);
325 void chunk_freelist_deallocate(Metachunk* chunk);
327 // Total of the space in the free chunks list
328 size_t free_chunks_total();
329 size_t free_chunks_total_in_bytes();
331 // Number of chunks in the free chunks list
332 size_t free_chunks_count();
334 void inc_free_chunks_total(size_t v, size_t count = 1) {
335 Atomic::add_ptr(count, &_free_chunks_count);
336 Atomic::add_ptr(v, &_free_chunks_total);
337 }
338 ChunkList* free_medium_chunks() { return &_free_chunks[1]; }
339 ChunkList* free_small_chunks() { return &_free_chunks[0]; }
340 ChunkList* free_humongous_chunks() { return &_free_chunks[2]; }
342 ChunkList* free_chunks(ChunkIndex index);
344 // Returns the list for the given chunk word size.
345 ChunkList* find_free_chunks_list(size_t word_size);
347 // Add and remove from a list by size. Selects
348 // list based on size of chunk.
349 void free_chunks_put(Metachunk* chuck);
350 Metachunk* free_chunks_get(size_t chunk_word_size);
352 // Debug support
353 void verify();
354 void locked_verify();
355 void verify_free_chunks_total();
357 void locked_print_free_chunks(outputStream* st);
358 void locked_print_sum_free_chunks(outputStream* st);
359 };
362 // Used to manage the free list of Metablocks (a block corresponds
363 // to the allocation of a quantum of metadata).
364 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
365 #ifdef DEALLOCATE_BLOCKS
366 BinaryTreeDictionary<Metablock>* _dictionary;
367 #endif
368 static Metablock* initialize_free_chunk(Metablock* block, size_t word_size);
370 #ifdef DEALLOCATE_BLOCKS
371 // Accessors
372 BinaryTreeDictionary<Metablock>* dictionary() const { return _dictionary; }
373 #endif
375 public:
376 BlockFreelist();
377 ~BlockFreelist();
379 // Get and return a block to the free list
380 Metablock* get_block(size_t word_size);
381 void return_block(Metablock* block, size_t word_size);
383 size_t totalSize() {
384 #ifdef DEALLOCATE_BLOCKS
385 if (dictionary() == NULL) {
386 return 0;
387 } else {
388 return dictionary()->totalSize();
389 }
390 #else
391 return 0;
392 #endif
393 }
395 void print_on(outputStream* st) const;
396 };
398 class VirtualSpaceNode : public CHeapObj<mtClass> {
399 friend class VirtualSpaceList;
401 // Link to next VirtualSpaceNode
402 VirtualSpaceNode* _next;
404 // total in the VirtualSpace
405 MemRegion _reserved;
406 ReservedSpace _rs;
407 VirtualSpace _virtual_space;
408 MetaWord* _top;
410 // Convenience functions for logical bottom and end
411 MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
412 MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
414 // Convenience functions to access the _virtual_space
415 char* low() const { return virtual_space()->low(); }
416 char* high() const { return virtual_space()->high(); }
418 public:
420 VirtualSpaceNode(size_t byte_size);
421 VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs) {}
422 ~VirtualSpaceNode();
424 // address of next available space in _virtual_space;
425 // Accessors
426 VirtualSpaceNode* next() { return _next; }
427 void set_next(VirtualSpaceNode* v) { _next = v; }
429 void set_reserved(MemRegion const v) { _reserved = v; }
430 void set_top(MetaWord* v) { _top = v; }
432 // Accessors
433 MemRegion* reserved() { return &_reserved; }
434 VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
436 // Returns true if "word_size" is available in the virtual space
437 bool is_available(size_t word_size) { return _top + word_size <= end(); }
439 MetaWord* top() const { return _top; }
440 void inc_top(size_t word_size) { _top += word_size; }
442 // used and capacity in this single entry in the list
443 size_t used_words_in_vs() const;
444 size_t capacity_words_in_vs() const;
446 bool initialize();
448 // get space from the virtual space
449 Metachunk* take_from_committed(size_t chunk_word_size);
451 // Allocate a chunk from the virtual space and return it.
452 Metachunk* get_chunk_vs(size_t chunk_word_size);
453 Metachunk* get_chunk_vs_with_expand(size_t chunk_word_size);
455 // Expands/shrinks the committed space in a virtual space. Delegates
456 // to Virtualspace
457 bool expand_by(size_t words, bool pre_touch = false);
458 bool shrink_by(size_t words);
460 // Debug support
461 static void verify_virtual_space_total();
462 static void verify_virtual_space_count();
463 void mangle();
465 void print_on(outputStream* st) const;
466 };
468 // byte_size is the size of the associated virtualspace.
469 VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(0) {
470 // This allocates memory with mmap. For DumpSharedspaces, allocate the
471 // space at low memory so that other shared images don't conflict.
472 // This is the same address as memory needed for UseCompressedOops but
473 // compressed oops don't work with CDS (offsets in metadata are wrong), so
474 // borrow the same address.
475 if (DumpSharedSpaces) {
476 char* shared_base = (char*)HeapBaseMinAddress;
477 _rs = ReservedSpace(byte_size, 0, false, shared_base, 0);
478 if (_rs.is_reserved()) {
479 assert(_rs.base() == shared_base, "should match");
480 } else {
481 // If we are dumping the heap, then allocate a wasted block of address
482 // space in order to push the heap to a lower address. This extra
483 // address range allows for other (or larger) libraries to be loaded
484 // without them occupying the space required for the shared spaces.
485 uintx reserved = 0;
486 uintx block_size = 64*1024*1024;
487 while (reserved < SharedDummyBlockSize) {
488 char* dummy = os::reserve_memory(block_size);
489 reserved += block_size;
490 }
491 _rs = ReservedSpace(byte_size);
492 }
493 MetaspaceShared::set_shared_rs(&_rs);
494 } else {
495 _rs = ReservedSpace(byte_size);
496 }
498 MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
499 }
501 // List of VirtualSpaces for metadata allocation.
502 // It has a _next link for singly linked list and a MemRegion
503 // for total space in the VirtualSpace.
504 class VirtualSpaceList : public CHeapObj<mtClass> {
505 friend class VirtualSpaceNode;
507 enum VirtualSpaceSizes {
508 VirtualSpaceSize = 256 * K
509 };
511 // Global list of virtual spaces
512 // Head of the list
513 VirtualSpaceNode* _virtual_space_list;
514 // virtual space currently being used for allocations
515 VirtualSpaceNode* _current_virtual_space;
516 // Free chunk list for all other metadata
517 ChunkManager _chunk_manager;
519 // Can this virtual list allocate >1 spaces? Also, used to determine
520 // whether to allocate unlimited small chunks in this virtual space
521 bool _is_class;
522 bool can_grow() const { return !is_class() || !UseCompressedKlassPointers; }
524 // Sum of space in all virtual spaces and number of virtual spaces
525 size_t _virtual_space_total;
526 size_t _virtual_space_count;
528 ~VirtualSpaceList();
530 VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
532 void set_virtual_space_list(VirtualSpaceNode* v) {
533 _virtual_space_list = v;
534 }
535 void set_current_virtual_space(VirtualSpaceNode* v) {
536 _current_virtual_space = v;
537 }
539 void link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size);
541 // Get another virtual space and add it to the list. This
542 // is typically prompted by a failed attempt to allocate a chunk
543 // and is typically followed by the allocation of a chunk.
544 bool grow_vs(size_t vs_word_size);
546 public:
547 VirtualSpaceList(size_t word_size);
548 VirtualSpaceList(ReservedSpace rs);
550 Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
552 VirtualSpaceNode* current_virtual_space() {
553 return _current_virtual_space;
554 }
556 ChunkManager* chunk_manager() { return &_chunk_manager; }
557 bool is_class() const { return _is_class; }
559 // Allocate the first virtualspace.
560 void initialize(size_t word_size);
562 size_t virtual_space_total() { return _virtual_space_total; }
563 void inc_virtual_space_total(size_t v) {
564 Atomic::add_ptr(v, &_virtual_space_total);
565 }
567 size_t virtual_space_count() { return _virtual_space_count; }
568 void inc_virtual_space_count() {
569 Atomic::inc_ptr(&_virtual_space_count);
570 }
572 // Used and capacity in the entire list of virtual spaces.
573 // These are global values shared by all Metaspaces
574 size_t capacity_words_sum();
575 size_t capacity_bytes_sum() { return capacity_words_sum() * BytesPerWord; }
576 size_t used_words_sum();
577 size_t used_bytes_sum() { return used_words_sum() * BytesPerWord; }
579 bool contains(const void *ptr);
581 void print_on(outputStream* st) const;
583 class VirtualSpaceListIterator : public StackObj {
584 VirtualSpaceNode* _virtual_spaces;
585 public:
586 VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
587 _virtual_spaces(virtual_spaces) {}
589 bool repeat() {
590 return _virtual_spaces != NULL;
591 }
593 VirtualSpaceNode* get_next() {
594 VirtualSpaceNode* result = _virtual_spaces;
595 if (_virtual_spaces != NULL) {
596 _virtual_spaces = _virtual_spaces->next();
597 }
598 return result;
599 }
600 };
601 };
604 class Metadebug : AllStatic {
605 // Debugging support for Metaspaces
606 static int _deallocate_block_a_lot_count;
607 static int _deallocate_chunk_a_lot_count;
608 static int _allocation_fail_alot_count;
610 public:
611 static int deallocate_block_a_lot_count() {
612 return _deallocate_block_a_lot_count;
613 }
614 static void set_deallocate_block_a_lot_count(int v) {
615 _deallocate_block_a_lot_count = v;
616 }
617 static void inc_deallocate_block_a_lot_count() {
618 _deallocate_block_a_lot_count++;
619 }
620 static int deallocate_chunk_a_lot_count() {
621 return _deallocate_chunk_a_lot_count;
622 }
623 static void reset_deallocate_chunk_a_lot_count() {
624 _deallocate_chunk_a_lot_count = 1;
625 }
626 static void inc_deallocate_chunk_a_lot_count() {
627 _deallocate_chunk_a_lot_count++;
628 }
630 static void init_allocation_fail_alot_count();
631 #ifdef ASSERT
632 static bool test_metadata_failure();
633 #endif
635 static void deallocate_chunk_a_lot(SpaceManager* sm,
636 size_t chunk_word_size);
637 static void deallocate_block_a_lot(SpaceManager* sm,
638 size_t chunk_word_size);
640 };
642 int Metadebug::_deallocate_block_a_lot_count = 0;
643 int Metadebug::_deallocate_chunk_a_lot_count = 0;
644 int Metadebug::_allocation_fail_alot_count = 0;
646 // SpaceManager - used by Metaspace to handle allocations
647 class SpaceManager : public CHeapObj<mtClass> {
648 friend class Metaspace;
649 friend class Metadebug;
651 private:
652 // protects allocations and contains.
653 Mutex* const _lock;
655 // List of chunks in use by this SpaceManager. Allocations
656 // are done from the current chunk. The list is used for deallocating
657 // chunks when the SpaceManager is freed.
658 Metachunk* _chunks_in_use[NumberOfFreeLists];
659 Metachunk* _current_chunk;
661 // Virtual space where allocation comes from.
662 VirtualSpaceList* _vs_list;
664 // Number of small chunks to allocate to a manager
665 // If class space manager, small chunks are unlimited
666 static uint const _small_chunk_limit;
667 bool has_small_chunk_limit() { return !vs_list()->is_class(); }
669 // Sum of all space in allocated chunks
670 size_t _allocation_total;
672 // Free lists of blocks are per SpaceManager since they
673 // are assumed to be in chunks in use by the SpaceManager
674 // and all chunks in use by a SpaceManager are freed when
675 // the class loader using the SpaceManager is collected.
676 BlockFreelist _block_freelists;
678 // protects virtualspace and chunk expansions
679 static const char* _expand_lock_name;
680 static const int _expand_lock_rank;
681 static Mutex* const _expand_lock;
683 // Accessors
684 Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
685 void set_chunks_in_use(ChunkIndex index, Metachunk* v) { _chunks_in_use[index] = v; }
687 BlockFreelist* block_freelists() const {
688 return (BlockFreelist*) &_block_freelists;
689 }
691 VirtualSpaceList* vs_list() const { return _vs_list; }
693 Metachunk* current_chunk() const { return _current_chunk; }
694 void set_current_chunk(Metachunk* v) {
695 _current_chunk = v;
696 }
698 Metachunk* find_current_chunk(size_t word_size);
700 // Add chunk to the list of chunks in use
701 void add_chunk(Metachunk* v, bool make_current);
703 // Debugging support
704 void verify_chunks_in_use_index(ChunkIndex index, Metachunk* v) {
705 switch (index) {
706 case 0:
707 assert(v->word_size() == SmallChunk, "Not a SmallChunk");
708 break;
709 case 1:
710 assert(v->word_size() == MediumChunk, "Not a MediumChunk");
711 break;
712 case 2:
713 assert(v->word_size() > MediumChunk, "Not a HumongousChunk");
714 break;
715 default:
716 assert(false, "Wrong list.");
717 }
718 }
720 protected:
721 Mutex* lock() const { return _lock; }
723 public:
724 SpaceManager(Mutex* lock, VirtualSpaceList* vs_list);
725 ~SpaceManager();
727 enum ChunkSizes { // in words.
728 SmallChunk = 512,
729 MediumChunk = 8 * K,
730 MediumChunkBunch = 4 * MediumChunk
731 };
733 // Accessors
734 size_t allocation_total() const { return _allocation_total; }
735 void inc_allocation_total(size_t v) { Atomic::add_ptr(v, &_allocation_total); }
736 static bool is_humongous(size_t word_size) { return word_size > MediumChunk; }
738 static Mutex* expand_lock() { return _expand_lock; }
740 size_t sum_capacity_in_chunks_in_use() const;
741 size_t sum_used_in_chunks_in_use() const;
742 size_t sum_free_in_chunks_in_use() const;
743 size_t sum_waste_in_chunks_in_use() const;
744 size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
746 size_t sum_count_in_chunks_in_use();
747 size_t sum_count_in_chunks_in_use(ChunkIndex i);
749 // Block allocation and deallocation.
750 // Allocates a block from the current chunk
751 MetaWord* allocate(size_t word_size);
753 // Helper for allocations
754 Metablock* allocate_work(size_t word_size);
756 // Returns a block to the per manager freelist
757 void deallocate(MetaWord* p);
759 // Based on the allocation size and a minimum chunk size,
760 // returned chunk size (for expanding space for chunk allocation).
761 size_t calc_chunk_size(size_t allocation_word_size);
763 // Called when an allocation from the current chunk fails.
764 // Gets a new chunk (may require getting a new virtual space),
765 // and allocates from that chunk.
766 Metablock* grow_and_allocate(size_t word_size);
768 // debugging support.
770 void dump(outputStream* const out) const;
771 void print_on(outputStream* st) const;
772 void locked_print_chunks_in_use_on(outputStream* st) const;
774 void verify();
775 #ifdef ASSERT
776 void mangle_freed_chunks();
777 void verify_allocation_total();
778 #endif
779 };
781 uint const SpaceManager::_small_chunk_limit = 4;
783 const char* SpaceManager::_expand_lock_name =
784 "SpaceManager chunk allocation lock";
785 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
786 Mutex* const SpaceManager::_expand_lock =
787 new Mutex(SpaceManager::_expand_lock_rank,
788 SpaceManager::_expand_lock_name,
789 Mutex::_allow_vm_block_flag);
791 #ifdef ASSERT
792 size_t Metablock::_overhead =
793 Chunk::aligned_overhead_size(sizeof(Metablock)) / BytesPerWord;
794 #else
795 size_t Metablock::_overhead = 0;
796 #endif
797 size_t Metachunk::_overhead =
798 Chunk::aligned_overhead_size(sizeof(Metachunk)) / BytesPerWord;
800 // New blocks returned by the Metaspace are zero initialized.
801 // We should fix the constructors to not assume this instead.
802 Metablock* Metablock::initialize(MetaWord* p, size_t word_size) {
803 Metablock* result = (Metablock*) p;
805 // Clear the memory
806 Copy::fill_to_aligned_words((HeapWord*)result, word_size);
807 #ifdef ASSERT
808 result->set_word_size(word_size);
809 // Check after work size is set.
810 result->set_leader((void*) metaspace_allocation_leader);
811 result->set_trailer((void*) metaspace_allocation_trailer);
812 #endif
813 return result;
814 }
816 void Metablock::verify() {
817 #ifdef ASSERT
818 assert(leader() == metaspace_allocation_leader &&
819 trailer() == metaspace_allocation_trailer,
820 "block has been corrupted");
821 #endif
822 }
824 // Metachunk methods
826 Metachunk* Metachunk::initialize(MetaWord* ptr, size_t word_size) {
827 // Set bottom, top, and end. Allow space for the Metachunk itself
828 Metachunk* chunk = (Metachunk*) ptr;
830 MetaWord* chunk_bottom = ptr + _overhead;
831 chunk->set_bottom(ptr);
832 chunk->set_top(chunk_bottom);
833 MetaWord* chunk_end = ptr + word_size;
834 assert(chunk_end > chunk_bottom, "Chunk must be too small");
835 chunk->set_end(chunk_end);
836 chunk->set_next(NULL);
837 chunk->set_word_size(word_size);
838 #ifdef ASSERT
839 size_t data_word_size = pointer_delta(chunk_end, chunk_bottom, sizeof(MetaWord));
840 Copy::fill_to_words((HeapWord*) chunk_bottom, data_word_size, metadata_chunk_initialize);
841 #endif
842 return chunk;
843 }
846 Metablock* Metachunk::allocate(size_t word_size) {
847 Metablock* result = NULL;
848 // If available, bump the pointer to allocate.
849 if (free_word_size() >= word_size) {
850 result = Metablock::initialize(_top, word_size);
851 _top = _top + word_size;
852 }
853 #ifdef ASSERT
854 assert(result == NULL ||
855 result->word_size() == word_size,
856 "Block size is not set correctly");
857 #endif
858 return result;
859 }
861 // _bottom points to the start of the chunk including the overhead.
862 size_t Metachunk::used_word_size() {
863 return pointer_delta(_top, _bottom, sizeof(MetaWord));
864 }
866 size_t Metachunk::free_word_size() {
867 return pointer_delta(_end, _top, sizeof(MetaWord));
868 }
870 size_t Metachunk::capacity_word_size() {
871 return pointer_delta(_end, _bottom, sizeof(MetaWord));
872 }
874 void Metachunk::print_on(outputStream* st) const {
875 st->print_cr("Metachunk:"
876 " bottom " PTR_FORMAT " top " PTR_FORMAT
877 " end " PTR_FORMAT " size " SIZE_FORMAT,
878 bottom(), top(), end(), word_size());
879 }
882 void Metachunk::verify() {
883 #ifdef ASSERT
884 // Cannot walk through the blocks unless the blocks have
885 // headers with sizes.
886 MetaWord* curr = bottom() + overhead();
887 while (curr < top()) {
888 Metablock* block = (Metablock*) curr;
889 size_t word_size = block->word_size();
890 block->verify();
891 curr = curr + word_size;
892 }
893 #endif
894 return;
895 }
897 // BlockFreelist methods
899 #ifdef DEALLOCATE_BLOCKS
900 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
901 #else
902 BlockFreelist::BlockFreelist() {}
903 #endif
905 BlockFreelist::~BlockFreelist() {
906 #ifdef DEALLOCATE_BLOCKS
907 if (_dictionary != NULL) {
908 if (Verbose && TraceMetadataChunkAllocation) {
909 _dictionary->print_free_lists(gclog_or_tty);
910 }
911 delete _dictionary;
912 }
913 #endif
914 }
916 Metablock* BlockFreelist::initialize_free_chunk(Metablock* block, size_t word_size) {
917 #ifdef DEALLOCATE_BLOCKS
918 #ifdef ASSERT
919 assert(word_size = block->word_size(), "Wrong chunk size");
920 #endif
921 Metablock* result = block;
922 result->setSize(word_size);
923 result->linkPrev(NULL);
924 result->linkNext(NULL);
926 return result;
927 #else
928 ShouldNotReachHere();
929 return block;
930 #endif
931 }
933 void BlockFreelist::return_block(Metablock* block, size_t word_size) {
934 #ifdef ASSERT
935 assert(word_size = block->word_size(), "Block size is wrong");;
936 #endif
937 Metablock* free_chunk = initialize_free_chunk(block, word_size);
938 #ifdef DEALLOCATE_BLOCKS
939 if (dictionary() == NULL) {
940 _dictionary = new BinaryTreeDictionary<Metablock>(false /* adaptive_freelists */);
941 }
942 dictionary()->returnChunk(free_chunk);
943 #endif
944 }
946 Metablock* BlockFreelist::get_block(size_t word_size) {
947 #ifdef DEALLOCATE_BLOCKS
948 if (dictionary() == NULL) {
949 return NULL;
950 }
952 Metablock* free_chunk =
953 dictionary()->getChunk(word_size, FreeBlockDictionary<Metablock>::exactly);
954 #else
955 Metablock* free_chunk = NULL;
956 #endif
957 if (free_chunk == NULL) {
958 return NULL;
959 }
960 assert(free_chunk->word_size() == word_size, "Size of chunk is incorrect");
961 Metablock* block = Metablock::initialize((MetaWord*) free_chunk, word_size);
962 #ifdef ASSERT
963 assert(block->word_size() == word_size, "Block size is not set correctly");
964 #endif
966 return block;
967 }
969 void BlockFreelist::print_on(outputStream* st) const {
970 #ifdef DEALLOCATE_BLOCKS
971 if (dictionary() == NULL) {
972 return;
973 }
974 dictionary()->print_free_lists(st);
975 #else
976 return;
977 #endif
978 }
980 // VirtualSpaceNode methods
982 VirtualSpaceNode::~VirtualSpaceNode() {
983 _rs.release();
984 }
986 size_t VirtualSpaceNode::used_words_in_vs() const {
987 return pointer_delta(top(), bottom(), sizeof(MetaWord));
988 }
990 // Space committed in the VirtualSpace
991 size_t VirtualSpaceNode::capacity_words_in_vs() const {
992 return pointer_delta(end(), bottom(), sizeof(MetaWord));
993 }
996 // Allocates the chunk from the virtual space only.
997 // This interface is also used internally for debugging. Not all
998 // chunks removed here are necessarily used for allocation.
999 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
1000 // Bottom of the new chunk
1001 MetaWord* chunk_limit = top();
1002 assert(chunk_limit != NULL, "Not safe to call this method");
1004 if (!is_available(chunk_word_size)) {
1005 if (TraceMetadataChunkAllocation) {
1006 tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
1007 // Dump some information about the virtual space that is nearly full
1008 print_on(tty);
1009 }
1010 return NULL;
1011 }
1013 // Take the space (bump top on the current virtual space).
1014 inc_top(chunk_word_size);
1016 // Point the chunk at the space
1017 Metachunk* result = Metachunk::initialize(chunk_limit, chunk_word_size);
1018 return result;
1019 }
1022 // Expand the virtual space (commit more of the reserved space)
1023 bool VirtualSpaceNode::expand_by(size_t words, bool pre_touch) {
1024 size_t bytes = words * BytesPerWord;
1025 bool result = virtual_space()->expand_by(bytes, pre_touch);
1026 if (TraceMetavirtualspaceAllocation && !result) {
1027 gclog_or_tty->print_cr("VirtualSpaceNode::expand_by() failed "
1028 "for byte size " SIZE_FORMAT, bytes);
1029 virtual_space()->print();
1030 }
1031 return result;
1032 }
1034 // Shrink the virtual space (commit more of the reserved space)
1035 bool VirtualSpaceNode::shrink_by(size_t words) {
1036 size_t bytes = words * BytesPerWord;
1037 virtual_space()->shrink_by(bytes);
1038 return true;
1039 }
1041 // Add another chunk to the chunk list.
1043 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
1044 assert_lock_strong(SpaceManager::expand_lock());
1045 Metachunk* result = NULL;
1047 return take_from_committed(chunk_word_size);
1048 }
1050 Metachunk* VirtualSpaceNode::get_chunk_vs_with_expand(size_t chunk_word_size) {
1051 assert_lock_strong(SpaceManager::expand_lock());
1053 Metachunk* new_chunk = get_chunk_vs(chunk_word_size);
1055 if (new_chunk == NULL) {
1056 // Only a small part of the virtualspace is committed when first
1057 // allocated so committing more here can be expected.
1058 size_t page_size_words = os::vm_page_size() / BytesPerWord;
1059 size_t aligned_expand_vs_by_words = align_size_up(chunk_word_size,
1060 page_size_words);
1061 expand_by(aligned_expand_vs_by_words, false);
1062 new_chunk = get_chunk_vs(chunk_word_size);
1063 }
1064 return new_chunk;
1065 }
1067 bool VirtualSpaceNode::initialize() {
1069 if (!_rs.is_reserved()) {
1070 return false;
1071 }
1073 // Commit only 1 page instead of the whole reserved space _rs.size()
1074 size_t committed_byte_size = os::vm_page_size();
1075 bool result = virtual_space()->initialize(_rs, committed_byte_size);
1076 if (result) {
1077 set_top((MetaWord*)virtual_space()->low());
1078 set_reserved(MemRegion((HeapWord*)_rs.base(),
1079 (HeapWord*)(_rs.base() + _rs.size())));
1081 assert(reserved()->start() == (HeapWord*) _rs.base(),
1082 err_msg("Reserved start was not set properly " PTR_FORMAT
1083 " != " PTR_FORMAT, reserved()->start(), _rs.base()));
1084 assert(reserved()->word_size() == _rs.size() / BytesPerWord,
1085 err_msg("Reserved size was not set properly " SIZE_FORMAT
1086 " != " SIZE_FORMAT, reserved()->word_size(),
1087 _rs.size() / BytesPerWord));
1088 }
1090 return result;
1091 }
1093 void VirtualSpaceNode::print_on(outputStream* st) const {
1094 size_t used = used_words_in_vs();
1095 size_t capacity = capacity_words_in_vs();
1096 VirtualSpace* vs = virtual_space();
1097 st->print_cr(" space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
1098 "[" PTR_FORMAT ", " PTR_FORMAT ", "
1099 PTR_FORMAT ", " PTR_FORMAT ")",
1100 vs, capacity / K, used * 100 / capacity,
1101 bottom(), top(), end(),
1102 vs->high_boundary());
1103 }
1105 void VirtualSpaceNode::mangle() {
1106 size_t word_size = capacity_words_in_vs();
1107 Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
1108 }
1110 // VirtualSpaceList methods
1111 // Space allocated from the VirtualSpace
1113 VirtualSpaceList::~VirtualSpaceList() {
1114 VirtualSpaceListIterator iter(virtual_space_list());
1115 while (iter.repeat()) {
1116 VirtualSpaceNode* vsl = iter.get_next();
1117 delete vsl;
1118 }
1119 }
1121 size_t VirtualSpaceList::used_words_sum() {
1122 size_t allocated_by_vs = 0;
1123 VirtualSpaceListIterator iter(virtual_space_list());
1124 while (iter.repeat()) {
1125 VirtualSpaceNode* vsl = iter.get_next();
1126 // Sum used region [bottom, top) in each virtualspace
1127 allocated_by_vs += vsl->used_words_in_vs();
1128 }
1129 assert(allocated_by_vs >= chunk_manager()->free_chunks_total(),
1130 err_msg("Total in free chunks " SIZE_FORMAT
1131 " greater than total from virtual_spaces " SIZE_FORMAT,
1132 allocated_by_vs, chunk_manager()->free_chunks_total()));
1133 size_t used =
1134 allocated_by_vs - chunk_manager()->free_chunks_total();
1135 return used;
1136 }
1138 // Space available in all MetadataVirtualspaces allocated
1139 // for metadata. This is the upper limit on the capacity
1140 // of chunks allocated out of all the MetadataVirtualspaces.
1141 size_t VirtualSpaceList::capacity_words_sum() {
1142 size_t capacity = 0;
1143 VirtualSpaceListIterator iter(virtual_space_list());
1144 while (iter.repeat()) {
1145 VirtualSpaceNode* vsl = iter.get_next();
1146 capacity += vsl->capacity_words_in_vs();
1147 }
1148 return capacity;
1149 }
1151 VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
1152 _is_class(false),
1153 _virtual_space_list(NULL),
1154 _current_virtual_space(NULL),
1155 _virtual_space_total(0),
1156 _virtual_space_count(0) {
1157 MutexLockerEx cl(SpaceManager::expand_lock(),
1158 Mutex::_no_safepoint_check_flag);
1159 bool initialization_succeeded = grow_vs(word_size);
1161 assert(initialization_succeeded,
1162 " VirtualSpaceList initialization should not fail");
1163 }
1165 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
1166 _is_class(true),
1167 _virtual_space_list(NULL),
1168 _current_virtual_space(NULL),
1169 _virtual_space_total(0),
1170 _virtual_space_count(0) {
1171 MutexLockerEx cl(SpaceManager::expand_lock(),
1172 Mutex::_no_safepoint_check_flag);
1173 VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
1174 bool succeeded = class_entry->initialize();
1175 assert(succeeded, " VirtualSpaceList initialization should not fail");
1176 link_vs(class_entry, rs.size()/BytesPerWord);
1177 }
1179 // Allocate another meta virtual space and add it to the list.
1180 bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
1181 assert_lock_strong(SpaceManager::expand_lock());
1182 if (vs_word_size == 0) {
1183 return false;
1184 }
1185 // Reserve the space
1186 size_t vs_byte_size = vs_word_size * BytesPerWord;
1187 assert(vs_byte_size % os::vm_page_size() == 0, "Not aligned");
1189 // Allocate the meta virtual space and initialize it.
1190 VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
1191 if (!new_entry->initialize()) {
1192 delete new_entry;
1193 return false;
1194 } else {
1195 link_vs(new_entry, vs_word_size);
1196 return true;
1197 }
1198 }
1200 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size) {
1201 if (virtual_space_list() == NULL) {
1202 set_virtual_space_list(new_entry);
1203 } else {
1204 current_virtual_space()->set_next(new_entry);
1205 }
1206 set_current_virtual_space(new_entry);
1207 inc_virtual_space_total(vs_word_size);
1208 inc_virtual_space_count();
1209 #ifdef ASSERT
1210 new_entry->mangle();
1211 #endif
1212 if (TraceMetavirtualspaceAllocation && Verbose) {
1213 VirtualSpaceNode* vsl = current_virtual_space();
1214 vsl->print_on(tty);
1215 }
1216 }
1218 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
1219 size_t grow_chunks_by_words) {
1221 // Get a chunk from the chunk freelist
1222 Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
1224 // Allocate a chunk out of the current virtual space.
1225 if (next == NULL) {
1226 next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1227 }
1229 if (next == NULL) {
1230 // Not enough room in current virtual space. Try to commit
1231 // more space.
1232 size_t expand_vs_by_words = MAX2((size_t)SpaceManager::MediumChunkBunch,
1233 grow_chunks_by_words);
1234 size_t page_size_words = os::vm_page_size() / BytesPerWord;
1235 size_t aligned_expand_vs_by_words = align_size_up(expand_vs_by_words,
1236 page_size_words);
1237 bool vs_expanded =
1238 current_virtual_space()->expand_by(aligned_expand_vs_by_words, false);
1239 if (!vs_expanded) {
1240 // Should the capacity of the metaspaces be expanded for
1241 // this allocation? If it's the virtual space for classes and is
1242 // being used for CompressedHeaders, don't allocate a new virtualspace.
1243 if (can_grow() && MetaspaceGC::should_expand(this, word_size)) {
1244 // Get another virtual space.
1245 size_t grow_vs_words =
1246 MAX2((size_t)VirtualSpaceSize, aligned_expand_vs_by_words);
1247 if (grow_vs(grow_vs_words)) {
1248 // Got it. It's on the list now. Get a chunk from it.
1249 next = current_virtual_space()->get_chunk_vs_with_expand(grow_chunks_by_words);
1250 }
1251 if (TraceMetadataHumongousAllocation && SpaceManager::is_humongous(word_size)) {
1252 gclog_or_tty->print_cr(" aligned_expand_vs_by_words " PTR_FORMAT,
1253 aligned_expand_vs_by_words);
1254 gclog_or_tty->print_cr(" grow_vs_words " PTR_FORMAT,
1255 grow_vs_words);
1256 }
1257 } else {
1258 // Allocation will fail and induce a GC
1259 if (TraceMetadataChunkAllocation && Verbose) {
1260 gclog_or_tty->print_cr("VirtualSpaceList::get_new_chunk():"
1261 " Fail instead of expand the metaspace");
1262 }
1263 }
1264 } else {
1265 // The virtual space expanded, get a new chunk
1266 next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1267 assert(next != NULL, "Just expanded, should succeed");
1268 }
1269 }
1271 return next;
1272 }
1274 void VirtualSpaceList::print_on(outputStream* st) const {
1275 if (TraceMetadataChunkAllocation && Verbose) {
1276 VirtualSpaceListIterator iter(virtual_space_list());
1277 while (iter.repeat()) {
1278 VirtualSpaceNode* node = iter.get_next();
1279 node->print_on(st);
1280 }
1281 }
1282 }
1284 #ifndef PRODUCT
1285 bool VirtualSpaceList::contains(const void *ptr) {
1286 VirtualSpaceNode* list = virtual_space_list();
1287 VirtualSpaceListIterator iter(list);
1288 while (iter.repeat()) {
1289 VirtualSpaceNode* node = iter.get_next();
1290 if (node->reserved()->contains(ptr)) {
1291 return true;
1292 }
1293 }
1294 return false;
1295 }
1296 #endif // PRODUCT
1299 // MetaspaceGC methods
1301 // VM_CollectForMetadataAllocation is the vm operation used to GC.
1302 // Within the VM operation after the GC the attempt to allocate the metadata
1303 // should succeed. If the GC did not free enough space for the metaspace
1304 // allocation, the HWM is increased so that another virtualspace will be
1305 // allocated for the metadata. With perm gen the increase in the perm
1306 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The
1307 // metaspace policy uses those as the small and large steps for the HWM.
1308 //
1309 // After the GC the compute_new_size() for MetaspaceGC is called to
1310 // resize the capacity of the metaspaces. The current implementation
1311 // is based on the flags MinHeapFreeRatio and MaxHeapFreeRatio used
1312 // to resize the Java heap by some GC's. New flags can be implemented
1313 // if really needed. MinHeapFreeRatio is used to calculate how much
1314 // free space is desirable in the metaspace capacity to decide how much
1315 // to increase the HWM. MaxHeapFreeRatio is used to decide how much
1316 // free space is desirable in the metaspace capacity before decreasing
1317 // the HWM.
1319 // Calculate the amount to increase the high water mark (HWM).
1320 // Increase by a minimum amount (MinMetaspaceExpansion) so that
1321 // another expansion is not requested too soon. If that is not
1322 // enough to satisfy the allocation (i.e. big enough for a word_size
1323 // allocation), increase by MaxMetaspaceExpansion. If that is still
1324 // not enough, expand by the size of the allocation (word_size) plus
1325 // some.
1326 size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
1327 size_t before_inc = MetaspaceGC::capacity_until_GC();
1328 size_t min_delta_words = MinMetaspaceExpansion / BytesPerWord;
1329 size_t max_delta_words = MaxMetaspaceExpansion / BytesPerWord;
1330 size_t page_size_words = os::vm_page_size() / BytesPerWord;
1331 size_t size_delta_words = align_size_up(word_size, page_size_words);
1332 size_t delta_words = MAX2(size_delta_words, min_delta_words);
1333 if (delta_words > min_delta_words) {
1334 // Don't want to hit the high water mark on the next
1335 // allocation so make the delta greater than just enough
1336 // for this allocation.
1337 delta_words = MAX2(delta_words, max_delta_words);
1338 if (delta_words > max_delta_words) {
1339 // This allocation is large but the next ones are probably not
1340 // so increase by the minimum.
1341 delta_words = delta_words + min_delta_words;
1342 }
1343 }
1344 return delta_words;
1345 }
1347 bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
1349 // Class virtual space should always be expanded. Call GC for the other
1350 // metadata virtual space.
1351 if (vsl == Metaspace::class_space_list()) return true;
1353 // If the user wants a limit, impose one.
1354 size_t max_metaspace_size_words = MaxMetaspaceSize / BytesPerWord;
1355 size_t metaspace_size_words = MetaspaceSize / BytesPerWord;
1356 if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
1357 vsl->capacity_words_sum() >= max_metaspace_size_words) {
1358 return false;
1359 }
1361 // If this is part of an allocation after a GC, expand
1362 // unconditionally.
1363 if(MetaspaceGC::expand_after_GC()) {
1364 return true;
1365 }
1367 // If the capacity is below the minimum capacity, allow the
1368 // expansion. Also set the high-water-mark (capacity_until_GC)
1369 // to that minimum capacity so that a GC will not be induced
1370 // until that minimum capacity is exceeded.
1371 if (vsl->capacity_words_sum() < metaspace_size_words ||
1372 capacity_until_GC() == 0) {
1373 set_capacity_until_GC(metaspace_size_words);
1374 return true;
1375 } else {
1376 if (vsl->capacity_words_sum() < capacity_until_GC()) {
1377 return true;
1378 } else {
1379 if (TraceMetadataChunkAllocation && Verbose) {
1380 gclog_or_tty->print_cr(" allocation request size " SIZE_FORMAT
1381 " capacity_until_GC " SIZE_FORMAT
1382 " capacity_words_sum " SIZE_FORMAT
1383 " used_words_sum " SIZE_FORMAT
1384 " free chunks " SIZE_FORMAT
1385 " free chunks count %d",
1386 word_size,
1387 capacity_until_GC(),
1388 vsl->capacity_words_sum(),
1389 vsl->used_words_sum(),
1390 vsl->chunk_manager()->free_chunks_total(),
1391 vsl->chunk_manager()->free_chunks_count());
1392 }
1393 return false;
1394 }
1395 }
1396 }
1398 // Variables are in bytes
1400 void MetaspaceGC::compute_new_size() {
1401 assert(_shrink_factor <= 100, "invalid shrink factor");
1402 uint current_shrink_factor = _shrink_factor;
1403 _shrink_factor = 0;
1405 VirtualSpaceList *vsl = Metaspace::space_list();
1407 size_t capacity_after_gc = vsl->capacity_bytes_sum();
1408 // Check to see if these two can be calculated without walking the CLDG
1409 size_t used_after_gc = vsl->used_bytes_sum();
1410 size_t capacity_until_GC = vsl->capacity_bytes_sum();
1411 size_t free_after_gc = capacity_until_GC - used_after_gc;
1413 const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
1414 const double maximum_used_percentage = 1.0 - minimum_free_percentage;
1416 const double min_tmp = used_after_gc / maximum_used_percentage;
1417 size_t minimum_desired_capacity =
1418 (size_t)MIN2(min_tmp, double(max_uintx));
1419 // Don't shrink less than the initial generation size
1420 minimum_desired_capacity = MAX2(minimum_desired_capacity,
1421 MetaspaceSize);
1423 if (PrintGCDetails && Verbose) {
1424 const double free_percentage = ((double)free_after_gc) / capacity_until_GC;
1425 gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
1426 gclog_or_tty->print_cr(" "
1427 " minimum_free_percentage: %6.2f"
1428 " maximum_used_percentage: %6.2f",
1429 minimum_free_percentage,
1430 maximum_used_percentage);
1431 double d_free_after_gc = free_after_gc / (double) K;
1432 gclog_or_tty->print_cr(" "
1433 " free_after_gc : %6.1fK"
1434 " used_after_gc : %6.1fK"
1435 " capacity_after_gc : %6.1fK"
1436 " metaspace HWM : %6.1fK",
1437 free_after_gc / (double) K,
1438 used_after_gc / (double) K,
1439 capacity_after_gc / (double) K,
1440 capacity_until_GC / (double) K);
1441 gclog_or_tty->print_cr(" "
1442 " free_percentage: %6.2f",
1443 free_percentage);
1444 }
1447 if (capacity_until_GC < minimum_desired_capacity) {
1448 // If we have less capacity below the metaspace HWM, then
1449 // increment the HWM.
1450 size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
1451 // Don't expand unless it's significant
1452 if (expand_bytes >= MinMetaspaceExpansion) {
1453 size_t expand_words = expand_bytes / BytesPerWord;
1454 MetaspaceGC::inc_capacity_until_GC(expand_words);
1455 }
1456 if (PrintGCDetails && Verbose) {
1457 size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
1458 gclog_or_tty->print_cr(" expanding:"
1459 " minimum_desired_capacity: %6.1fK"
1460 " expand_words: %6.1fK"
1461 " MinMetaspaceExpansion: %6.1fK"
1462 " new metaspace HWM: %6.1fK",
1463 minimum_desired_capacity / (double) K,
1464 expand_bytes / (double) K,
1465 MinMetaspaceExpansion / (double) K,
1466 new_capacity_until_GC / (double) K);
1467 }
1468 return;
1469 }
1471 // No expansion, now see if we want to shrink
1472 size_t shrink_words = 0;
1473 // We would never want to shrink more than this
1474 size_t max_shrink_words = capacity_until_GC - minimum_desired_capacity;
1475 assert(max_shrink_words >= 0, err_msg("max_shrink_words " SIZE_FORMAT,
1476 max_shrink_words));
1478 // Should shrinking be considered?
1479 if (MaxHeapFreeRatio < 100) {
1480 const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
1481 const double minimum_used_percentage = 1.0 - maximum_free_percentage;
1482 const double max_tmp = used_after_gc / minimum_used_percentage;
1483 size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
1484 maximum_desired_capacity = MAX2(maximum_desired_capacity,
1485 MetaspaceSize);
1486 if (PrintGC && Verbose) {
1487 gclog_or_tty->print_cr(" "
1488 " maximum_free_percentage: %6.2f"
1489 " minimum_used_percentage: %6.2f",
1490 maximum_free_percentage,
1491 minimum_used_percentage);
1492 gclog_or_tty->print_cr(" "
1493 " capacity_until_GC: %6.1fK"
1494 " minimum_desired_capacity: %6.1fK"
1495 " maximum_desired_capacity: %6.1fK",
1496 capacity_until_GC / (double) K,
1497 minimum_desired_capacity / (double) K,
1498 maximum_desired_capacity / (double) K);
1499 }
1501 assert(minimum_desired_capacity <= maximum_desired_capacity,
1502 "sanity check");
1504 if (capacity_until_GC > maximum_desired_capacity) {
1505 // Capacity too large, compute shrinking size
1506 shrink_words = capacity_until_GC - maximum_desired_capacity;
1507 // We don't want shrink all the way back to initSize if people call
1508 // System.gc(), because some programs do that between "phases" and then
1509 // we'd just have to grow the heap up again for the next phase. So we
1510 // damp the shrinking: 0% on the first call, 10% on the second call, 40%
1511 // on the third call, and 100% by the fourth call. But if we recompute
1512 // size without shrinking, it goes back to 0%.
1513 shrink_words = shrink_words / 100 * current_shrink_factor;
1514 assert(shrink_words <= max_shrink_words,
1515 err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
1516 shrink_words, max_shrink_words));
1517 if (current_shrink_factor == 0) {
1518 _shrink_factor = 10;
1519 } else {
1520 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
1521 }
1522 if (PrintGCDetails && Verbose) {
1523 gclog_or_tty->print_cr(" "
1524 " shrinking:"
1525 " initSize: %.1fK"
1526 " maximum_desired_capacity: %.1fK",
1527 MetaspaceSize / (double) K,
1528 maximum_desired_capacity / (double) K);
1529 gclog_or_tty->print_cr(" "
1530 " shrink_words: %.1fK"
1531 " current_shrink_factor: %d"
1532 " new shrink factor: %d"
1533 " MinMetaspaceExpansion: %.1fK",
1534 shrink_words / (double) K,
1535 current_shrink_factor,
1536 _shrink_factor,
1537 MinMetaspaceExpansion / (double) K);
1538 }
1539 }
1540 }
1543 // Don't shrink unless it's significant
1544 if (shrink_words >= MinMetaspaceExpansion) {
1545 VirtualSpaceNode* csp = vsl->current_virtual_space();
1546 size_t available_to_shrink = csp->capacity_words_in_vs() -
1547 csp->used_words_in_vs();
1548 shrink_words = MIN2(shrink_words, available_to_shrink);
1549 csp->shrink_by(shrink_words);
1550 MetaspaceGC::dec_capacity_until_GC(shrink_words);
1551 if (PrintGCDetails && Verbose) {
1552 size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
1553 gclog_or_tty->print_cr(" metaspace HWM: %.1fK", new_capacity_until_GC / (double) K);
1554 }
1555 }
1556 assert(vsl->used_bytes_sum() == used_after_gc &&
1557 used_after_gc <= vsl->capacity_bytes_sum(),
1558 "sanity check");
1560 }
1562 // Metadebug methods
1564 void Metadebug::deallocate_chunk_a_lot(SpaceManager* sm,
1565 size_t chunk_word_size){
1566 #ifdef ASSERT
1567 VirtualSpaceList* vsl = sm->vs_list();
1568 if (MetaDataDeallocateALot &&
1569 Metadebug::deallocate_chunk_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
1570 Metadebug::reset_deallocate_chunk_a_lot_count();
1571 for (uint i = 0; i < metadata_deallocate_a_lock_chunk; i++) {
1572 Metachunk* dummy_chunk = vsl->current_virtual_space()->take_from_committed(chunk_word_size);
1573 if (dummy_chunk == NULL) {
1574 break;
1575 }
1576 vsl->chunk_manager()->chunk_freelist_deallocate(dummy_chunk);
1578 if (TraceMetadataChunkAllocation && Verbose) {
1579 gclog_or_tty->print("Metadebug::deallocate_chunk_a_lot: %d) ",
1580 sm->sum_count_in_chunks_in_use());
1581 dummy_chunk->print_on(gclog_or_tty);
1582 gclog_or_tty->print_cr(" Free chunks total %d count %d",
1583 vsl->chunk_manager()->free_chunks_total(),
1584 vsl->chunk_manager()->free_chunks_count());
1585 }
1586 }
1587 } else {
1588 Metadebug::inc_deallocate_chunk_a_lot_count();
1589 }
1590 #endif
1591 }
1593 void Metadebug::deallocate_block_a_lot(SpaceManager* sm,
1594 size_t raw_word_size){
1595 #ifdef ASSERT
1596 if (MetaDataDeallocateALot &&
1597 Metadebug::deallocate_block_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
1598 Metadebug::set_deallocate_block_a_lot_count(0);
1599 for (uint i = 0; i < metadata_deallocate_a_lot_block; i++) {
1600 Metablock* dummy_block = sm->allocate_work(raw_word_size);
1601 if (dummy_block == 0) {
1602 break;
1603 }
1604 #ifdef ASSERT
1605 assert(dummy_block->word_size() == raw_word_size, "Block size is not set correctly");
1606 #endif
1607 sm->deallocate(dummy_block->data());
1608 }
1609 } else {
1610 Metadebug::inc_deallocate_block_a_lot_count();
1611 }
1612 #endif
1613 }
1615 void Metadebug::init_allocation_fail_alot_count() {
1616 if (MetadataAllocationFailALot) {
1617 _allocation_fail_alot_count =
1618 1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
1619 }
1620 }
1622 #ifdef ASSERT
1623 bool Metadebug::test_metadata_failure() {
1624 if (MetadataAllocationFailALot &&
1625 Threads::is_vm_complete()) {
1626 if (_allocation_fail_alot_count > 0) {
1627 _allocation_fail_alot_count--;
1628 } else {
1629 if (TraceMetadataChunkAllocation && Verbose) {
1630 gclog_or_tty->print_cr("Metadata allocation failing for "
1631 "MetadataAllocationFailALot");
1632 }
1633 init_allocation_fail_alot_count();
1634 return true;
1635 }
1636 }
1637 return false;
1638 }
1639 #endif
1641 // ChunkList methods
1643 size_t ChunkList::sum_list_size() {
1644 size_t result = 0;
1645 Metachunk* cur = head();
1646 while (cur != NULL) {
1647 result += cur->word_size();
1648 cur = cur->next();
1649 }
1650 return result;
1651 }
1653 size_t ChunkList::sum_list_count() {
1654 size_t result = 0;
1655 Metachunk* cur = head();
1656 while (cur != NULL) {
1657 result++;
1658 cur = cur->next();
1659 }
1660 return result;
1661 }
1663 size_t ChunkList::sum_list_capacity() {
1664 size_t result = 0;
1665 Metachunk* cur = head();
1666 while (cur != NULL) {
1667 result += cur->capacity_word_size();
1668 cur = cur->next();
1669 }
1670 return result;
1671 }
1673 void ChunkList::add_at_head(Metachunk* head, Metachunk* tail) {
1674 assert_lock_strong(SpaceManager::expand_lock());
1675 assert(tail->next() == NULL, "Not the tail");
1677 if (TraceMetadataChunkAllocation && Verbose) {
1678 tty->print("ChunkList::add_at_head: ");
1679 Metachunk* cur = head;
1680 while (cur != NULL) {
1681 tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ", cur, cur->word_size());
1682 cur = cur->next();
1683 }
1684 tty->print_cr("");
1685 }
1687 if (tail != NULL) {
1688 tail->set_next(_head);
1689 }
1690 set_head(head);
1691 }
1693 void ChunkList::add_at_head(Metachunk* list) {
1694 if (list == NULL) {
1695 // Nothing to add
1696 return;
1697 }
1698 assert_lock_strong(SpaceManager::expand_lock());
1699 Metachunk* head = list;
1700 Metachunk* tail = list;
1701 Metachunk* cur = head->next();
1702 // Search for the tail since it is not passed.
1703 while (cur != NULL) {
1704 tail = cur;
1705 cur = cur->next();
1706 }
1707 add_at_head(head, tail);
1708 }
1710 // ChunkManager methods
1712 // Verification of _free_chunks_total and _free_chunks_count does not
1713 // work with the CMS collector because its use of additional locks
1714 // complicate the mutex deadlock detection but it can still be useful
1715 // for detecting errors in the chunk accounting with other collectors.
1717 size_t ChunkManager::free_chunks_total() {
1718 #ifdef ASSERT
1719 if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1720 MutexLockerEx cl(SpaceManager::expand_lock(),
1721 Mutex::_no_safepoint_check_flag);
1722 locked_verify_free_chunks_total();
1723 }
1724 #endif
1725 return _free_chunks_total;
1726 }
1728 size_t ChunkManager::free_chunks_total_in_bytes() {
1729 return free_chunks_total() * BytesPerWord;
1730 }
1732 size_t ChunkManager::free_chunks_count() {
1733 #ifdef ASSERT
1734 if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1735 MutexLockerEx cl(SpaceManager::expand_lock(),
1736 Mutex::_no_safepoint_check_flag);
1737 // This lock is only needed in debug because the verification
1738 // of the _free_chunks_totals walks the list of free chunks
1739 locked_verify_free_chunks_count();
1740 }
1741 #endif
1742 return _free_chunks_count;
1743 }
1745 void ChunkManager::locked_verify_free_chunks_total() {
1746 assert_lock_strong(SpaceManager::expand_lock());
1747 assert(sum_free_chunks() == _free_chunks_total,
1748 err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
1749 " same as sum " SIZE_FORMAT, _free_chunks_total,
1750 sum_free_chunks()));
1751 }
1753 void ChunkManager::verify_free_chunks_total() {
1754 MutexLockerEx cl(SpaceManager::expand_lock(),
1755 Mutex::_no_safepoint_check_flag);
1756 locked_verify_free_chunks_total();
1757 }
1759 void ChunkManager::locked_verify_free_chunks_count() {
1760 assert_lock_strong(SpaceManager::expand_lock());
1761 assert(sum_free_chunks_count() == _free_chunks_count,
1762 err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
1763 " same as sum " SIZE_FORMAT, _free_chunks_count,
1764 sum_free_chunks_count()));
1765 }
1767 void ChunkManager::verify_free_chunks_count() {
1768 #ifdef ASSERT
1769 MutexLockerEx cl(SpaceManager::expand_lock(),
1770 Mutex::_no_safepoint_check_flag);
1771 locked_verify_free_chunks_count();
1772 #endif
1773 }
1775 void ChunkManager::verify() {
1776 #ifdef ASSERT
1777 if (!UseConcMarkSweepGC) {
1778 MutexLockerEx cl(SpaceManager::expand_lock(),
1779 Mutex::_no_safepoint_check_flag);
1780 locked_verify_free_chunks_total();
1781 locked_verify_free_chunks_count();
1782 }
1783 #endif
1784 }
1786 void ChunkManager::locked_verify() {
1787 locked_verify_free_chunks_total();
1788 locked_verify_free_chunks_count();
1789 }
1791 void ChunkManager::locked_print_free_chunks(outputStream* st) {
1792 assert_lock_strong(SpaceManager::expand_lock());
1793 st->print_cr("Free chunk total 0x%x count 0x%x",
1794 _free_chunks_total, _free_chunks_count);
1795 }
1797 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
1798 assert_lock_strong(SpaceManager::expand_lock());
1799 st->print_cr("Sum free chunk total 0x%x count 0x%x",
1800 sum_free_chunks(), sum_free_chunks_count());
1801 }
1802 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
1803 return &_free_chunks[index];
1804 }
1807 // These methods that sum the free chunk lists are used in printing
1808 // methods that are used in product builds.
1809 size_t ChunkManager::sum_free_chunks() {
1810 assert_lock_strong(SpaceManager::expand_lock());
1811 size_t result = 0;
1812 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1813 ChunkList* list = free_chunks(i);
1815 if (list == NULL) {
1816 continue;
1817 }
1819 result = result + list->sum_list_capacity();
1820 }
1821 return result;
1822 }
1824 size_t ChunkManager::sum_free_chunks_count() {
1825 assert_lock_strong(SpaceManager::expand_lock());
1826 size_t count = 0;
1827 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1828 ChunkList* list = free_chunks(i);
1829 if (list == NULL) {
1830 continue;
1831 }
1832 count = count + list->sum_list_count();
1833 }
1834 return count;
1835 }
1837 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
1838 switch (word_size) {
1839 case SpaceManager::SmallChunk :
1840 return &_free_chunks[0];
1841 case SpaceManager::MediumChunk :
1842 return &_free_chunks[1];
1843 default:
1844 assert(word_size > SpaceManager::MediumChunk, "List inconsistency");
1845 return &_free_chunks[2];
1846 }
1847 }
1849 void ChunkManager::free_chunks_put(Metachunk* chunk) {
1850 assert_lock_strong(SpaceManager::expand_lock());
1851 ChunkList* free_list = find_free_chunks_list(chunk->word_size());
1852 chunk->set_next(free_list->head());
1853 free_list->set_head(chunk);
1854 // chunk is being returned to the chunk free list
1855 inc_free_chunks_total(chunk->capacity_word_size());
1856 locked_verify();
1857 }
1859 void ChunkManager::chunk_freelist_deallocate(Metachunk* chunk) {
1860 // The deallocation of a chunk originates in the freelist
1861 // manangement code for a Metaspace and does not hold the
1862 // lock.
1863 assert(chunk != NULL, "Deallocating NULL");
1864 // MutexLockerEx fcl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
1865 locked_verify();
1866 if (TraceMetadataChunkAllocation) {
1867 tty->print_cr("ChunkManager::chunk_freelist_deallocate: chunk "
1868 PTR_FORMAT " size " SIZE_FORMAT,
1869 chunk, chunk->word_size());
1870 }
1871 free_chunks_put(chunk);
1872 }
1874 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
1875 assert_lock_strong(SpaceManager::expand_lock());
1877 locked_verify();
1878 ChunkList* free_list = find_free_chunks_list(word_size);
1879 assert(free_list != NULL, "Sanity check");
1881 Metachunk* chunk = free_list->head();
1882 debug_only(Metachunk* debug_head = chunk;)
1884 if (chunk == NULL) {
1885 return NULL;
1886 }
1888 Metachunk* prev_chunk = chunk;
1889 if (chunk->word_size() == word_size) {
1890 // Chunk is being removed from the chunks free list.
1891 dec_free_chunks_total(chunk->capacity_word_size());
1892 // Remove the chunk as the head of the list.
1893 free_list->set_head(chunk->next());
1894 chunk->set_next(NULL);
1896 if (TraceMetadataChunkAllocation && Verbose) {
1897 tty->print_cr("ChunkManager::free_chunks_get: free_list "
1898 PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
1899 free_list, chunk, chunk->word_size());
1900 }
1901 } else {
1902 assert(SpaceManager::is_humongous(word_size),
1903 "Should only need to check humongous");
1904 // This code to find the best fit is just for purposes of
1905 // investigating the loss due to fragmentation on a humongous
1906 // chunk. It will be replace by a binaryTreeDictionary for
1907 // the humongous chunks.
1908 uint count = 0;
1909 Metachunk* best_fit = NULL;
1910 Metachunk* best_fit_prev = NULL;
1911 while (chunk != NULL) {
1912 count++;
1913 if (chunk->word_size() < word_size) {
1914 prev_chunk = chunk;
1915 chunk = chunk->next();
1916 } else if (chunk->word_size() == word_size) {
1917 break;
1918 } else {
1919 if (best_fit == NULL ||
1920 best_fit->word_size() > chunk->word_size()) {
1921 best_fit_prev = prev_chunk;
1922 best_fit = chunk;
1923 }
1924 prev_chunk = chunk;
1925 chunk = chunk->next();
1926 }
1927 }
1928 if (chunk == NULL) {
1929 prev_chunk = best_fit_prev;
1930 chunk = best_fit;
1931 }
1932 if (chunk != NULL) {
1933 if (TraceMetadataHumongousAllocation) {
1934 size_t waste = chunk->word_size() - word_size;
1935 tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
1936 " for requested size " SIZE_FORMAT
1937 " waste " SIZE_FORMAT
1938 " found at " SIZE_FORMAT " of " SIZE_FORMAT,
1939 chunk->word_size(), word_size, waste,
1940 count, free_list->sum_list_count());
1941 }
1942 // Chunk is being removed from the chunks free list.
1943 dec_free_chunks_total(chunk->capacity_word_size());
1944 // Remove the chunk if it is at the head of the list.
1945 if (chunk == free_list->head()) {
1946 free_list->set_head(chunk->next());
1948 if (TraceMetadataHumongousAllocation) {
1949 tty->print_cr("ChunkManager::free_chunks_get: humongous free_list "
1950 PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT
1951 " new head " PTR_FORMAT,
1952 free_list, chunk, chunk->word_size(),
1953 free_list->head());
1954 }
1955 } else {
1956 // Remove a chunk in the interior of the list
1957 prev_chunk->set_next(chunk->next());
1959 if (TraceMetadataHumongousAllocation) {
1960 tty->print_cr("ChunkManager::free_chunks_get: humongous free_list "
1961 PTR_FORMAT " chunk " PTR_FORMAT " size " SIZE_FORMAT
1962 PTR_FORMAT " prev " PTR_FORMAT " next " PTR_FORMAT,
1963 free_list, chunk, chunk->word_size(),
1964 prev_chunk, chunk->next());
1965 }
1966 }
1967 chunk->set_next(NULL);
1968 } else {
1969 if (TraceMetadataHumongousAllocation) {
1970 tty->print_cr("ChunkManager::free_chunks_get: New humongous chunk of size "
1971 SIZE_FORMAT,
1972 word_size);
1973 }
1974 }
1975 }
1976 locked_verify();
1977 return chunk;
1978 }
1980 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
1981 assert_lock_strong(SpaceManager::expand_lock());
1982 locked_verify();
1984 // Take from the beginning of the list
1985 Metachunk* chunk = free_chunks_get(word_size);
1986 if (chunk == NULL) {
1987 return NULL;
1988 }
1990 assert(word_size <= chunk->word_size() ||
1991 SpaceManager::is_humongous(chunk->word_size()),
1992 "Non-humongous variable sized chunk");
1993 if (TraceMetadataChunkAllocation) {
1994 tty->print("ChunkManager::chunk_freelist_allocate: chunk "
1995 PTR_FORMAT " size " SIZE_FORMAT " ",
1996 chunk, chunk->word_size());
1997 locked_print_free_chunks(tty);
1998 }
2000 return chunk;
2001 }
2003 // SpaceManager methods
2005 size_t SpaceManager::sum_free_in_chunks_in_use() const {
2006 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2007 size_t free = 0;
2008 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2009 Metachunk* chunk = chunks_in_use(i);
2010 while (chunk != NULL) {
2011 free += chunk->free_word_size();
2012 chunk = chunk->next();
2013 }
2014 }
2015 return free;
2016 }
2018 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
2019 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2020 size_t result = 0;
2021 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2022 // Count the free space in all the chunk but not the
2023 // current chunk from which allocations are still being done.
2024 result += sum_waste_in_chunks_in_use(i);
2025 }
2026 return result;
2027 }
2029 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
2030 size_t result = 0;
2031 size_t count = 0;
2032 Metachunk* chunk = chunks_in_use(index);
2033 // Count the free space in all the chunk but not the
2034 // current chunk from which allocations are still being done.
2035 if (chunk != NULL) {
2036 while (chunk != NULL) {
2037 if (chunk != current_chunk()) {
2038 result += chunk->free_word_size();
2039 }
2040 chunk = chunk->next();
2041 count++;
2042 }
2043 }
2044 return result;
2045 }
2047 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
2048 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2049 size_t sum = 0;
2050 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2051 Metachunk* chunk = chunks_in_use(i);
2052 while (chunk != NULL) {
2053 // Just changed this sum += chunk->capacity_word_size();
2054 // sum += chunk->word_size() - Metachunk::overhead();
2055 sum += chunk->capacity_word_size();
2056 chunk = chunk->next();
2057 }
2058 }
2059 return sum;
2060 }
2062 size_t SpaceManager::sum_count_in_chunks_in_use() {
2063 size_t count = 0;
2064 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2065 count = count + sum_count_in_chunks_in_use(i);
2066 }
2067 return count;
2068 }
2070 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
2071 size_t count = 0;
2072 Metachunk* chunk = chunks_in_use(i);
2073 while (chunk != NULL) {
2074 count++;
2075 chunk = chunk->next();
2076 }
2077 return count;
2078 }
2081 size_t SpaceManager::sum_used_in_chunks_in_use() const {
2082 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2083 size_t used = 0;
2084 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2085 Metachunk* chunk = chunks_in_use(i);
2086 while (chunk != NULL) {
2087 used += chunk->used_word_size();
2088 chunk = chunk->next();
2089 }
2090 }
2091 return used;
2092 }
2094 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
2096 Metachunk* small_chunk = chunks_in_use(SmallIndex);
2097 st->print_cr("SpaceManager: small chunk " PTR_FORMAT
2098 " free " SIZE_FORMAT,
2099 small_chunk,
2100 small_chunk->free_word_size());
2102 Metachunk* medium_chunk = chunks_in_use(MediumIndex);
2103 st->print("medium chunk " PTR_FORMAT, medium_chunk);
2104 Metachunk* tail = current_chunk();
2105 st->print_cr(" current chunk " PTR_FORMAT, tail);
2107 Metachunk* head = chunks_in_use(HumongousIndex);
2108 st->print_cr("humongous chunk " PTR_FORMAT, head);
2110 vs_list()->chunk_manager()->locked_print_free_chunks(st);
2111 vs_list()->chunk_manager()->locked_print_sum_free_chunks(st);
2112 }
2114 size_t SpaceManager::calc_chunk_size(size_t word_size) {
2116 // Decide between a small chunk and a medium chunk. Up to
2117 // _small_chunk_limit small chunks can be allocated but
2118 // once a medium chunk has been allocated, no more small
2119 // chunks will be allocated.
2120 size_t chunk_word_size;
2121 if (chunks_in_use(MediumIndex) == NULL &&
2122 (!has_small_chunk_limit() ||
2123 sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit)) {
2124 chunk_word_size = (size_t) SpaceManager::SmallChunk;
2125 if (word_size + Metachunk::overhead() > SpaceManager::SmallChunk) {
2126 chunk_word_size = MediumChunk;
2127 }
2128 } else {
2129 chunk_word_size = MediumChunk;
2130 }
2132 // Might still need a humongous chunk
2133 chunk_word_size =
2134 MAX2((size_t) chunk_word_size, word_size + Metachunk::overhead());
2136 if (TraceMetadataHumongousAllocation &&
2137 SpaceManager::is_humongous(word_size)) {
2138 gclog_or_tty->print_cr("Metadata humongous allocation:");
2139 gclog_or_tty->print_cr(" word_size " PTR_FORMAT, word_size);
2140 gclog_or_tty->print_cr(" chunk_word_size " PTR_FORMAT,
2141 chunk_word_size);
2142 gclog_or_tty->print_cr(" block overhead " PTR_FORMAT
2143 " chunk overhead " PTR_FORMAT,
2144 Metablock::overhead(),
2145 Metachunk::overhead());
2146 }
2147 return chunk_word_size;
2148 }
2150 Metablock* SpaceManager::grow_and_allocate(size_t word_size) {
2151 assert(vs_list()->current_virtual_space() != NULL,
2152 "Should have been set");
2153 assert(current_chunk() == NULL ||
2154 current_chunk()->allocate(word_size) == NULL,
2155 "Don't need to expand");
2156 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2158 if (TraceMetadataChunkAllocation && Verbose) {
2159 gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
2160 " words " SIZE_FORMAT " space left",
2161 word_size, current_chunk() != NULL ?
2162 current_chunk()->free_word_size() : 0);
2163 }
2165 // Get another chunk out of the virtual space
2166 size_t grow_chunks_by_words = calc_chunk_size(word_size);
2167 Metachunk* next = vs_list()->get_new_chunk(word_size, grow_chunks_by_words);
2169 // If a chunk was available, add it to the in-use chunk list
2170 // and do an allocation from it.
2171 if (next != NULL) {
2172 Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
2173 // Add to this manager's list of chunks in use.
2174 add_chunk(next, false);
2175 return next->allocate(word_size);
2176 }
2177 return NULL;
2178 }
2180 void SpaceManager::print_on(outputStream* st) const {
2182 for (ChunkIndex i = SmallIndex;
2183 i < NumberOfFreeLists ;
2184 i = next_chunk_index(i) ) {
2185 st->print_cr(" chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
2186 chunks_in_use(i),
2187 chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
2188 }
2189 st->print_cr(" waste: Small " SIZE_FORMAT " Medium " SIZE_FORMAT
2190 " Humongous " SIZE_FORMAT,
2191 sum_waste_in_chunks_in_use(SmallIndex),
2192 sum_waste_in_chunks_in_use(MediumIndex),
2193 sum_waste_in_chunks_in_use(HumongousIndex));
2194 // Nothing in them yet
2195 // block_freelists()->print_on(st);
2196 }
2198 SpaceManager::SpaceManager(Mutex* lock, VirtualSpaceList* vs_list) :
2199 _vs_list(vs_list),
2200 _allocation_total(0),
2201 _lock(lock) {
2202 Metadebug::init_allocation_fail_alot_count();
2203 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2204 _chunks_in_use[i] = NULL;
2205 }
2206 _current_chunk = NULL;
2207 if (TraceMetadataChunkAllocation && Verbose) {
2208 gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
2209 }
2210 }
2212 SpaceManager::~SpaceManager() {
2213 MutexLockerEx fcl(SpaceManager::expand_lock(),
2214 Mutex::_no_safepoint_check_flag);
2216 ChunkManager* chunk_manager = vs_list()->chunk_manager();
2218 chunk_manager->locked_verify();
2220 if (TraceMetadataChunkAllocation && Verbose) {
2221 gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
2222 locked_print_chunks_in_use_on(gclog_or_tty);
2223 }
2225 // Have to update before the chunks_in_use lists are emptied
2226 // below.
2227 chunk_manager->inc_free_chunks_total(sum_capacity_in_chunks_in_use(),
2228 sum_count_in_chunks_in_use());
2230 #ifdef ASSERT
2231 // Mangle freed memory.
2232 mangle_freed_chunks();
2233 #endif // ASSERT
2235 // Add all the chunks in use by this space manager
2236 // to the global list of free chunks.
2238 // Small chunks. There is one _current_chunk for each
2239 // Metaspace. It could point to a small or medium chunk.
2240 // Rather than determine which it is, follow the list of
2241 // small chunks to add them to the free list
2242 Metachunk* small_chunk = chunks_in_use(SmallIndex);
2243 chunk_manager->free_small_chunks()->add_at_head(small_chunk);
2244 set_chunks_in_use(SmallIndex, NULL);
2246 // After the small chunk are the medium chunks
2247 Metachunk* medium_chunk = chunks_in_use(MediumIndex);
2248 assert(medium_chunk == NULL ||
2249 medium_chunk->word_size() == MediumChunk,
2250 "Chunk is on the wrong list");
2252 if (medium_chunk != NULL) {
2253 Metachunk* head = medium_chunk;
2254 // If there is a medium chunk then the _current_chunk can only
2255 // point to the last medium chunk.
2256 Metachunk* tail = current_chunk();
2257 chunk_manager->free_medium_chunks()->add_at_head(head, tail);
2258 set_chunks_in_use(MediumIndex, NULL);
2259 }
2261 // Humongous chunks
2262 // Humongous chunks are never the current chunk.
2263 Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
2265 if (humongous_chunks != NULL) {
2266 chunk_manager->free_humongous_chunks()->add_at_head(humongous_chunks);
2267 set_chunks_in_use(HumongousIndex, NULL);
2268 }
2269 chunk_manager->locked_verify();
2270 }
2272 void SpaceManager::deallocate(MetaWord* p) {
2273 assert_lock_strong(_lock);
2274 ShouldNotReachHere(); // Where is this needed.
2275 #ifdef DEALLOCATE_BLOCKS
2276 Metablock* block = Metablock::metablock_from_data(p);
2277 // This is expense but kept it until integration JJJ
2278 assert(contains((address)block), "Block does not belong to this metaspace");
2279 block_freelists()->return_block(block, word_size);
2280 #endif
2281 }
2283 // Adds a chunk to the list of chunks in use.
2284 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
2286 assert(new_chunk != NULL, "Should not be NULL");
2287 assert(new_chunk->next() == NULL, "Should not be on a list");
2289 new_chunk->reset_empty();
2291 // Find the correct list and and set the current
2292 // chunk for that list.
2293 switch (new_chunk->word_size()) {
2294 case SpaceManager::SmallChunk :
2295 if (chunks_in_use(SmallIndex) == NULL) {
2296 // First chunk to add to the list
2297 set_chunks_in_use(SmallIndex, new_chunk);
2298 } else {
2299 assert(current_chunk()->word_size() == SpaceManager::SmallChunk,
2300 err_msg( "Incorrect mix of sizes in chunk list "
2301 SIZE_FORMAT " new chunk " SIZE_FORMAT,
2302 current_chunk()->word_size(), new_chunk->word_size()));
2303 current_chunk()->set_next(new_chunk);
2304 }
2305 // Make current chunk
2306 set_current_chunk(new_chunk);
2307 break;
2308 case SpaceManager::MediumChunk :
2309 if (chunks_in_use(MediumIndex) == NULL) {
2310 // About to add the first medium chunk so teminate the
2311 // small chunk list. In general once medium chunks are
2312 // being added, we're past the need for small chunks.
2313 if (current_chunk() != NULL) {
2314 // Only a small chunk or the initial chunk could be
2315 // the current chunk if this is the first medium chunk.
2316 assert(current_chunk()->word_size() == SpaceManager::SmallChunk ||
2317 chunks_in_use(SmallIndex) == NULL,
2318 err_msg("Should be a small chunk or initial chunk, current chunk "
2319 SIZE_FORMAT " new chunk " SIZE_FORMAT,
2320 current_chunk()->word_size(), new_chunk->word_size()));
2321 current_chunk()->set_next(NULL);
2322 }
2323 // First chunk to add to the list
2324 set_chunks_in_use(MediumIndex, new_chunk);
2326 } else {
2327 // As a minimum the first medium chunk added would
2328 // have become the _current_chunk
2329 // so the _current_chunk has to be non-NULL here
2330 // (although not necessarily still the first medium chunk).
2331 assert(current_chunk()->word_size() == SpaceManager::MediumChunk,
2332 "A medium chunk should the current chunk");
2333 current_chunk()->set_next(new_chunk);
2334 }
2335 // Make current chunk
2336 set_current_chunk(new_chunk);
2337 break;
2338 default: {
2339 // For null class loader data and DumpSharedSpaces, the first chunk isn't
2340 // small, so small will be null. Link this first chunk as the current
2341 // chunk.
2342 if (make_current) {
2343 // Set as the current chunk but otherwise treat as a humongous chunk.
2344 set_current_chunk(new_chunk);
2345 }
2346 // Link at head. The _current_chunk only points to a humongous chunk for
2347 // the null class loader metaspace (class and data virtual space managers)
2348 // any humongous chunks so will not point to the tail
2349 // of the humongous chunks list.
2350 new_chunk->set_next(chunks_in_use(HumongousIndex));
2351 set_chunks_in_use(HumongousIndex, new_chunk);
2353 assert(new_chunk->word_size() > MediumChunk, "List inconsistency");
2354 }
2355 }
2357 assert(new_chunk->is_empty(), "Not ready for reuse");
2358 if (TraceMetadataChunkAllocation && Verbose) {
2359 gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
2360 sum_count_in_chunks_in_use());
2361 new_chunk->print_on(gclog_or_tty);
2362 vs_list()->chunk_manager()->locked_print_free_chunks(tty);
2363 }
2364 }
2366 MetaWord* SpaceManager::allocate(size_t word_size) {
2367 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2369 size_t block_overhead = Metablock::overhead();
2370 // If only the dictionary is going to be used (i.e., no
2371 // indexed free list), then there is a minimum size requirement.
2372 // MinChunkSize is a placeholder for the real minimum size JJJ
2373 size_t byte_size_with_overhead = (word_size + block_overhead) * BytesPerWord;
2374 #ifdef DEALLOCATE_BLOCKS
2375 size_t raw_bytes_size = MAX2(ARENA_ALIGN(byte_size_with_overhead),
2376 MinChunkSize * BytesPerWord);
2377 #else
2378 size_t raw_bytes_size = ARENA_ALIGN(byte_size_with_overhead);
2379 #endif
2380 size_t raw_word_size = raw_bytes_size / BytesPerWord;
2381 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
2383 BlockFreelist* fl = block_freelists();
2384 Metablock* block = NULL;
2385 // Allocation from the dictionary is expensive in the sense that
2386 // the dictionary has to be searched for a size. Don't allocate
2387 // from the dictionary until it starts to get fat. Is this
2388 // a reasonable policy? Maybe an skinny dictionary is fast enough
2389 // for allocations. Do some profiling. JJJ
2390 if (fl->totalSize() > allocation_from_dictionary_limit) {
2391 block = fl->get_block(raw_word_size);
2392 }
2393 if (block == NULL) {
2394 block = allocate_work(raw_word_size);
2395 if (block == NULL) {
2396 return NULL;
2397 }
2398 }
2399 Metadebug::deallocate_block_a_lot(this, raw_word_size);
2401 // Push the allocation past the word containing the size and leader.
2402 #ifdef ASSERT
2403 MetaWord* result = block->data();
2404 return result;
2405 #else
2406 return (MetaWord*) block;
2407 #endif
2408 }
2410 // Returns the address of spaced allocated for "word_size".
2411 // This methods does not know about blocks (Metablocks)
2412 Metablock* SpaceManager::allocate_work(size_t word_size) {
2413 assert_lock_strong(_lock);
2414 #ifdef ASSERT
2415 if (Metadebug::test_metadata_failure()) {
2416 return NULL;
2417 }
2418 #endif
2419 // Is there space in the current chunk?
2420 Metablock* result = NULL;
2422 // For DumpSharedSpaces, only allocate out of the current chunk which is
2423 // never null because we gave it the size we wanted. Caller reports out
2424 // of memory if this returns null.
2425 if (DumpSharedSpaces) {
2426 assert(current_chunk() != NULL, "should never happen");
2427 inc_allocation_total(word_size);
2428 return current_chunk()->allocate(word_size); // caller handles null result
2429 }
2430 if (current_chunk() != NULL) {
2431 result = current_chunk()->allocate(word_size);
2432 }
2434 if (result == NULL) {
2435 result = grow_and_allocate(word_size);
2436 }
2437 if (result > 0) {
2438 inc_allocation_total(word_size);
2439 assert(result != (Metablock*) chunks_in_use(MediumIndex), "Head of the list is being allocated");
2440 assert(result->word_size() == word_size, "Size not set correctly");
2441 }
2443 return result;
2444 }
2446 void SpaceManager::verify() {
2447 // If there are blocks in the dictionary, then
2448 // verfication of chunks does not work since
2449 // being in the dictionary alters a chunk.
2450 if (block_freelists()->totalSize() == 0) {
2451 // Skip the small chunks because their next link points to
2452 // medium chunks. This is because the small chunk is the
2453 // current chunk (for allocations) until it is full and the
2454 // the addition of the next chunk does not NULL the next
2455 // like of the small chunk.
2456 for (ChunkIndex i = MediumIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
2457 Metachunk* curr = chunks_in_use(i);
2458 while (curr != NULL) {
2459 curr->verify();
2460 curr = curr->next();
2461 }
2462 }
2463 }
2464 }
2466 #ifdef ASSERT
2467 void SpaceManager::verify_allocation_total() {
2468 #if 0
2469 // Verification is only guaranteed at a safepoint.
2470 if (SafepointSynchronize::is_at_safepoint()) {
2471 gclog_or_tty->print_cr("Chunk " PTR_FORMAT " allocation_total " SIZE_FORMAT
2472 " sum_used_in_chunks_in_use " SIZE_FORMAT,
2473 this,
2474 allocation_total(),
2475 sum_used_in_chunks_in_use());
2476 }
2477 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2478 assert(allocation_total() == sum_used_in_chunks_in_use(),
2479 err_msg("allocation total is not consistent %d vs %d",
2480 allocation_total(), sum_used_in_chunks_in_use()));
2481 #endif
2482 }
2484 #endif
2486 void SpaceManager::dump(outputStream* const out) const {
2487 size_t curr_total = 0;
2488 size_t waste = 0;
2489 uint i = 0;
2490 size_t used = 0;
2491 size_t capacity = 0;
2493 // Add up statistics for all chunks in this SpaceManager.
2494 for (ChunkIndex index = SmallIndex;
2495 index < NumberOfFreeLists;
2496 index = next_chunk_index(index)) {
2497 for (Metachunk* curr = chunks_in_use(index);
2498 curr != NULL;
2499 curr = curr->next()) {
2500 out->print("%d) ", i++);
2501 curr->print_on(out);
2502 if (TraceMetadataChunkAllocation && Verbose) {
2503 block_freelists()->print_on(out);
2504 }
2505 curr_total += curr->word_size();
2506 used += curr->used_word_size();
2507 capacity += curr->capacity_word_size();
2508 waste += curr->free_word_size() + curr->overhead();;
2509 }
2510 }
2512 size_t free = current_chunk()->free_word_size();
2513 // Free space isn't wasted.
2514 waste -= free;
2516 out->print_cr("total of all chunks " SIZE_FORMAT " used " SIZE_FORMAT
2517 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
2518 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
2519 }
2521 #ifndef PRODUCT
2522 void SpaceManager::mangle_freed_chunks() {
2523 for (ChunkIndex index = SmallIndex;
2524 index < NumberOfFreeLists;
2525 index = next_chunk_index(index)) {
2526 for (Metachunk* curr = chunks_in_use(index);
2527 curr != NULL;
2528 curr = curr->next()) {
2529 // Try to detect incorrectly terminated small chunk
2530 // list.
2531 assert(index == MediumIndex || curr != chunks_in_use(MediumIndex),
2532 err_msg("Mangling medium chunks in small chunks? "
2533 "curr " PTR_FORMAT " medium list " PTR_FORMAT,
2534 curr, chunks_in_use(MediumIndex)));
2535 curr->mangle();
2536 }
2537 }
2538 }
2539 #endif // PRODUCT
2542 // MetaspaceAux
2544 size_t MetaspaceAux::used_in_bytes(Metaspace::MetadataType mdtype) {
2545 size_t used = 0;
2546 ClassLoaderDataGraphMetaspaceIterator iter;
2547 while (iter.repeat()) {
2548 Metaspace* msp = iter.get_next();
2549 // Sum allocation_total for each metaspace
2550 if (msp != NULL) {
2551 used += msp->used_words(mdtype);
2552 }
2553 }
2554 return used * BytesPerWord;
2555 }
2557 size_t MetaspaceAux::free_in_bytes(Metaspace::MetadataType mdtype) {
2558 size_t free = 0;
2559 ClassLoaderDataGraphMetaspaceIterator iter;
2560 while (iter.repeat()) {
2561 Metaspace* msp = iter.get_next();
2562 if (msp != NULL) {
2563 free += msp->free_words(mdtype);
2564 }
2565 }
2566 return free * BytesPerWord;
2567 }
2569 // The total words available for metadata allocation. This
2570 // uses Metaspace capacity_words() which is the total words
2571 // in chunks allocated for a Metaspace.
2572 size_t MetaspaceAux::capacity_in_bytes(Metaspace::MetadataType mdtype) {
2573 size_t capacity = free_chunks_total(mdtype);
2574 ClassLoaderDataGraphMetaspaceIterator iter;
2575 while (iter.repeat()) {
2576 Metaspace* msp = iter.get_next();
2577 if (msp != NULL) {
2578 capacity += msp->capacity_words(mdtype);
2579 }
2580 }
2581 return capacity * BytesPerWord;
2582 }
2584 size_t MetaspaceAux::reserved_in_bytes(Metaspace::MetadataType mdtype) {
2585 size_t reserved = (mdtype == Metaspace::ClassType) ?
2586 Metaspace::class_space_list()->virtual_space_total() :
2587 Metaspace::space_list()->virtual_space_total();
2588 return reserved * BytesPerWord;
2589 }
2591 size_t MetaspaceAux::min_chunk_size() { return SpaceManager::MediumChunk; }
2593 size_t MetaspaceAux::free_chunks_total(Metaspace::MetadataType mdtype) {
2594 ChunkManager* chunk = (mdtype == Metaspace::ClassType) ?
2595 Metaspace::class_space_list()->chunk_manager() :
2596 Metaspace::space_list()->chunk_manager();
2598 chunk->verify_free_chunks_total();
2599 return chunk->free_chunks_total();
2600 }
2602 size_t MetaspaceAux::free_chunks_total_in_bytes(Metaspace::MetadataType mdtype) {
2603 return free_chunks_total(mdtype) * BytesPerWord;
2604 }
2606 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
2607 gclog_or_tty->print(", [Metaspace:");
2608 if (PrintGCDetails && Verbose) {
2609 gclog_or_tty->print(" " SIZE_FORMAT
2610 "->" SIZE_FORMAT
2611 "(" SIZE_FORMAT "/" SIZE_FORMAT ")",
2612 prev_metadata_used,
2613 used_in_bytes(),
2614 capacity_in_bytes(),
2615 reserved_in_bytes());
2616 } else {
2617 gclog_or_tty->print(" " SIZE_FORMAT "K"
2618 "->" SIZE_FORMAT "K"
2619 "(" SIZE_FORMAT "K/" SIZE_FORMAT "K)",
2620 prev_metadata_used / K,
2621 used_in_bytes()/ K,
2622 capacity_in_bytes()/K,
2623 reserved_in_bytes()/ K);
2624 }
2626 gclog_or_tty->print("]");
2627 }
2629 // This is printed when PrintGCDetails
2630 void MetaspaceAux::print_on(outputStream* out) {
2631 Metaspace::MetadataType ct = Metaspace::ClassType;
2632 Metaspace::MetadataType nct = Metaspace::NonClassType;
2634 out->print_cr(" Metaspace total "
2635 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2636 " reserved " SIZE_FORMAT "K",
2637 capacity_in_bytes()/K, used_in_bytes()/K, reserved_in_bytes()/K);
2638 out->print_cr(" data space "
2639 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2640 " reserved " SIZE_FORMAT "K",
2641 capacity_in_bytes(nct)/K, used_in_bytes(nct)/K, reserved_in_bytes(nct)/K);
2642 out->print_cr(" class space "
2643 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2644 " reserved " SIZE_FORMAT "K",
2645 capacity_in_bytes(ct)/K, used_in_bytes(ct)/K, reserved_in_bytes(ct)/K);
2646 }
2648 // Print information for class space and data space separately.
2649 // This is almost the same as above.
2650 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
2651 size_t free_chunks_capacity_bytes = free_chunks_total_in_bytes(mdtype);
2652 size_t capacity_bytes = capacity_in_bytes(mdtype);
2653 size_t used_bytes = used_in_bytes(mdtype);
2654 size_t free_bytes = free_in_bytes(mdtype);
2655 size_t used_and_free = used_bytes + free_bytes +
2656 free_chunks_capacity_bytes;
2657 out->print_cr(" Chunk accounting: used in chunks " SIZE_FORMAT
2658 "K + unused in chunks " SIZE_FORMAT "K + "
2659 " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
2660 "K capacity in allocated chunks " SIZE_FORMAT "K",
2661 used_bytes / K,
2662 free_bytes / K,
2663 free_chunks_capacity_bytes / K,
2664 used_and_free / K,
2665 capacity_bytes / K);
2666 assert(used_and_free == capacity_bytes, "Accounting is wrong");
2667 }
2669 // Print total fragmentation for class and data metaspaces separately
2670 void MetaspaceAux::print_waste(outputStream* out) {
2672 size_t small_waste = 0, medium_waste = 0, large_waste = 0;
2673 size_t cls_small_waste = 0, cls_medium_waste = 0, cls_large_waste = 0;
2675 ClassLoaderDataGraphMetaspaceIterator iter;
2676 while (iter.repeat()) {
2677 Metaspace* msp = iter.get_next();
2678 if (msp != NULL) {
2679 small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2680 medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2681 large_waste += msp->vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
2683 cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2684 cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2685 cls_large_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
2686 }
2687 }
2688 out->print_cr("Total fragmentation waste (words) doesn't count free space");
2689 out->print(" data: small " SIZE_FORMAT " medium " SIZE_FORMAT,
2690 small_waste, medium_waste);
2691 out->print_cr(" class: small " SIZE_FORMAT, cls_small_waste);
2692 }
2694 // Dump global metaspace things from the end of ClassLoaderDataGraph
2695 void MetaspaceAux::dump(outputStream* out) {
2696 out->print_cr("All Metaspace:");
2697 out->print("data space: "); print_on(out, Metaspace::NonClassType);
2698 out->print("class space: "); print_on(out, Metaspace::ClassType);
2699 print_waste(out);
2700 }
2702 // Metaspace methods
2704 size_t Metaspace::_first_chunk_word_size = 0;
2706 Metaspace::Metaspace(Mutex* lock, size_t word_size) {
2707 initialize(lock, word_size);
2708 }
2710 Metaspace::Metaspace(Mutex* lock) {
2711 initialize(lock);
2712 }
2714 Metaspace::~Metaspace() {
2715 delete _vsm;
2716 delete _class_vsm;
2717 }
2719 VirtualSpaceList* Metaspace::_space_list = NULL;
2720 VirtualSpaceList* Metaspace::_class_space_list = NULL;
2722 #define VIRTUALSPACEMULTIPLIER 2
2724 void Metaspace::global_initialize() {
2725 // Initialize the alignment for shared spaces.
2726 int max_alignment = os::vm_page_size();
2727 MetaspaceShared::set_max_alignment(max_alignment);
2729 if (DumpSharedSpaces) {
2730 SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
2731 SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
2732 SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment);
2733 SharedMiscCodeSize = align_size_up(SharedMiscCodeSize, max_alignment);
2735 // Initialize with the sum of the shared space sizes. The read-only
2736 // and read write metaspace chunks will be allocated out of this and the
2737 // remainder is the misc code and data chunks.
2738 size_t total = align_size_up(SharedReadOnlySize + SharedReadWriteSize +
2739 SharedMiscDataSize + SharedMiscCodeSize,
2740 os::vm_allocation_granularity());
2741 size_t word_size = total/wordSize;
2742 _space_list = new VirtualSpaceList(word_size);
2743 } else {
2744 // If using shared space, open the file that contains the shared space
2745 // and map in the memory before initializing the rest of metaspace (so
2746 // the addresses don't conflict)
2747 if (UseSharedSpaces) {
2748 FileMapInfo* mapinfo = new FileMapInfo();
2749 memset(mapinfo, 0, sizeof(FileMapInfo));
2751 // Open the shared archive file, read and validate the header. If
2752 // initialization fails, shared spaces [UseSharedSpaces] are
2753 // disabled and the file is closed.
2754 // Map in spaces now also
2755 if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
2756 FileMapInfo::set_current_info(mapinfo);
2757 } else {
2758 assert(!mapinfo->is_open() && !UseSharedSpaces,
2759 "archive file not closed or shared spaces not disabled.");
2760 }
2761 }
2763 // Initialize this before initializing the VirtualSpaceList
2764 _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
2765 // Arbitrarily set the initial virtual space to a multiple
2766 // of the boot class loader size.
2767 size_t word_size = VIRTUALSPACEMULTIPLIER * Metaspace::first_chunk_word_size();
2768 // Initialize the list of virtual spaces.
2769 _space_list = new VirtualSpaceList(word_size);
2770 }
2771 }
2773 // For UseCompressedKlassPointers the class space is reserved as a piece of the
2774 // Java heap because the compression algorithm is the same for each. The
2775 // argument passed in is at the top of the compressed space
2776 void Metaspace::initialize_class_space(ReservedSpace rs) {
2777 // The reserved space size may be bigger because of alignment, esp with UseLargePages
2778 assert(rs.size() >= ClassMetaspaceSize, err_msg("%d != %d", rs.size(), ClassMetaspaceSize));
2779 _class_space_list = new VirtualSpaceList(rs);
2780 }
2783 void Metaspace::initialize(Mutex* lock, size_t initial_size) {
2784 // Use SmallChunk size if not specified. If specified, use this size for
2785 // the data metaspace.
2786 size_t word_size;
2787 size_t class_word_size;
2788 if (initial_size == 0) {
2789 word_size = (size_t) SpaceManager::SmallChunk;
2790 class_word_size = (size_t) SpaceManager::SmallChunk;
2791 } else {
2792 word_size = initial_size;
2793 // Make the first class chunk bigger than a medium chunk so it's not put
2794 // on the medium chunk list. The next chunk will be small and progress
2795 // from there. This size calculated by -version.
2796 class_word_size = MIN2((size_t)SpaceManager::MediumChunk*5,
2797 (ClassMetaspaceSize/BytesPerWord)*2);
2798 }
2800 assert(space_list() != NULL,
2801 "Metadata VirtualSpaceList has not been initialized");
2803 _vsm = new SpaceManager(lock, space_list());
2804 if (_vsm == NULL) {
2805 return;
2806 }
2808 assert(class_space_list() != NULL,
2809 "Class VirtualSpaceList has not been initialized");
2811 // Allocate SpaceManager for classes.
2812 _class_vsm = new SpaceManager(lock, class_space_list());
2813 if (_class_vsm == NULL) {
2814 return;
2815 }
2817 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2819 // Allocate chunk for metadata objects
2820 Metachunk* new_chunk =
2821 space_list()->current_virtual_space()->get_chunk_vs_with_expand(word_size);
2822 assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
2823 if (new_chunk != NULL) {
2824 // Add to this manager's list of chunks in use and current_chunk().
2825 vsm()->add_chunk(new_chunk, true);
2826 }
2828 // Allocate chunk for class metadata objects
2829 Metachunk* class_chunk =
2830 class_space_list()->current_virtual_space()->get_chunk_vs_with_expand(class_word_size);
2831 if (class_chunk != NULL) {
2832 class_vsm()->add_chunk(class_chunk, true);
2833 }
2834 }
2837 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
2838 // DumpSharedSpaces doesn't use class metadata area (yet)
2839 if (mdtype == ClassType && !DumpSharedSpaces) {
2840 return class_vsm()->allocate(word_size);
2841 } else {
2842 return vsm()->allocate(word_size);
2843 }
2844 }
2846 // Space allocated in the Metaspace. This may
2847 // be across several metadata virtual spaces.
2848 char* Metaspace::bottom() const {
2849 assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
2850 return (char*)vsm()->current_chunk()->bottom();
2851 }
2853 size_t Metaspace::used_words(MetadataType mdtype) const {
2854 // return vsm()->allocation_total();
2855 return mdtype == ClassType ? class_vsm()->sum_used_in_chunks_in_use() :
2856 vsm()->sum_used_in_chunks_in_use(); // includes overhead!
2857 }
2859 size_t Metaspace::free_words(MetadataType mdtype) const {
2860 return mdtype == ClassType ? class_vsm()->sum_free_in_chunks_in_use() :
2861 vsm()->sum_free_in_chunks_in_use();
2862 }
2864 // Space capacity in the Metaspace. It includes
2865 // space in the list of chunks from which allocations
2866 // have been made. Don't include space in the global freelist and
2867 // in the space available in the dictionary which
2868 // is already counted in some chunk.
2869 size_t Metaspace::capacity_words(MetadataType mdtype) const {
2870 return mdtype == ClassType ? class_vsm()->sum_capacity_in_chunks_in_use() :
2871 vsm()->sum_capacity_in_chunks_in_use();
2872 }
2874 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
2875 if (SafepointSynchronize::is_at_safepoint()) {
2876 assert(Thread::current()->is_VM_thread(), "should be the VM thread");
2877 // Don't take lock
2878 #ifdef DEALLOCATE_BLOCKS
2879 if (is_class) {
2880 class_vsm()->deallocate(ptr);
2881 } else {
2882 vsm()->deallocate(ptr);
2883 }
2884 #else
2885 #ifdef ASSERT
2886 Copy::fill_to_words((HeapWord*)ptr, word_size, metadata_deallocate);
2887 #endif
2888 #endif
2890 } else {
2891 MutexLocker ml(vsm()->lock());
2893 #ifdef DEALLOCATE_BLOCKS
2894 if (is_class) {
2895 class_vsm()->deallocate(ptr);
2896 } else {
2897 vsm()->deallocate(ptr);
2898 }
2899 #else
2900 #ifdef ASSERT
2901 Copy::fill_to_words((HeapWord*)ptr, word_size, metadata_deallocate);
2902 #endif
2903 #endif
2904 }
2905 }
2907 MetaWord* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
2908 bool read_only, MetadataType mdtype, TRAPS) {
2909 if (HAS_PENDING_EXCEPTION) {
2910 assert(false, "Should not allocate with exception pending");
2911 return NULL; // caller does a CHECK_NULL too
2912 }
2914 // SSS: Should we align the allocations and make sure the sizes are aligned.
2915 MetaWord* result = NULL;
2917 assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
2918 "ClassLoaderData::the_null_class_loader_data() should have been used.");
2919 // Allocate in metaspaces without taking out a lock, because it deadlocks
2920 // with the SymbolTable_lock. Dumping is single threaded for now. We'll have
2921 // to revisit this for application class data sharing.
2922 if (DumpSharedSpaces) {
2923 if (read_only) {
2924 result = loader_data->ro_metaspace()->allocate(word_size, NonClassType);
2925 } else {
2926 result = loader_data->rw_metaspace()->allocate(word_size, NonClassType);
2927 }
2928 if (result == NULL) {
2929 report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
2930 }
2931 return result;
2932 }
2934 result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
2936 if (result == NULL) {
2937 // Try to clean out some memory and retry.
2938 result =
2939 Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
2940 loader_data, word_size, mdtype);
2942 // If result is still null, we are out of memory.
2943 if (result == NULL) {
2944 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
2945 report_java_out_of_memory("Metadata space");
2947 if (JvmtiExport::should_post_resource_exhausted()) {
2948 JvmtiExport::post_resource_exhausted(
2949 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
2950 "Metadata space");
2951 }
2952 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
2953 }
2954 }
2955 return result;
2956 }
2958 void Metaspace::print_on(outputStream* out) const {
2959 // Print both class virtual space counts and metaspace.
2960 if (Verbose) {
2961 vsm()->print_on(out);
2962 class_vsm()->print_on(out);
2963 }
2964 }
2966 #ifndef PRODUCT
2967 bool Metaspace::contains(const void * ptr) const {
2968 if (MetaspaceShared::is_in_shared_space(ptr)) {
2969 return true;
2970 }
2971 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2972 return space_list()->contains(ptr) || class_space_list()->contains(ptr);
2973 }
2974 #endif
2976 void Metaspace::verify() {
2977 vsm()->verify();
2978 class_vsm()->verify();
2979 }
2981 void Metaspace::dump(outputStream* const out) const {
2982 if (UseMallocOnly) {
2983 // Just print usage for now
2984 out->print_cr("usage %d", used_words(Metaspace::NonClassType));
2985 }
2986 out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
2987 vsm()->dump(out);
2988 out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
2989 class_vsm()->dump(out);
2990 }