Fri, 16 Nov 2012 09:19:12 -0500
Merge
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.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24 #include "precompiled.hpp"
25 #include "gc_interface/collectedHeap.hpp"
26 #include "memory/binaryTreeDictionary.hpp"
27 #include "memory/freeList.hpp"
28 #include "memory/collectorPolicy.hpp"
29 #include "memory/filemap.hpp"
30 #include "memory/freeList.hpp"
31 #include "memory/metablock.hpp"
32 #include "memory/metachunk.hpp"
33 #include "memory/metaspace.hpp"
34 #include "memory/metaspaceShared.hpp"
35 #include "memory/resourceArea.hpp"
36 #include "memory/universe.hpp"
37 #include "runtime/globals.hpp"
38 #include "runtime/mutex.hpp"
39 #include "services/memTracker.hpp"
40 #include "utilities/copy.hpp"
41 #include "utilities/debug.hpp"
43 typedef BinaryTreeDictionary<Metablock, FreeList> BlockTreeDictionary;
44 typedef BinaryTreeDictionary<Metachunk, FreeList> ChunkTreeDictionary;
45 // Define this macro to enable slow integrity checking of
46 // the free chunk lists
47 const bool metaspace_slow_verify = false;
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;
57 MetaWord* last_allocated = 0;
59 // Used in declarations in SpaceManager and ChunkManager
60 enum ChunkIndex {
61 SmallIndex = 0,
62 MediumIndex = 1,
63 HumongousIndex = 2,
64 NumberOfFreeLists = 2,
65 NumberOfInUseLists = 3
66 };
68 static ChunkIndex next_chunk_index(ChunkIndex i) {
69 assert(i < NumberOfInUseLists, "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 size_t Metablock::_min_block_byte_size = sizeof(Metablock);
104 #ifdef ASSERT
105 size_t Metablock::_overhead =
106 Chunk::aligned_overhead_size(sizeof(Metablock)) / BytesPerWord;
107 #else
108 size_t Metablock::_overhead = 0;
109 #endif
112 // Pointer to list of Metachunks.
113 class ChunkList VALUE_OBJ_CLASS_SPEC {
114 // List of free chunks
115 Metachunk* _head;
117 public:
118 // Constructor
119 ChunkList() : _head(NULL) {}
121 // Accessors
122 Metachunk* head() { return _head; }
123 void set_head(Metachunk* v) { _head = v; }
125 // Link at head of the list
126 void add_at_head(Metachunk* head, Metachunk* tail);
127 void add_at_head(Metachunk* head);
129 size_t sum_list_size();
130 size_t sum_list_count();
131 size_t sum_list_capacity();
132 };
134 // Manages the global free lists of chunks.
135 // Has three lists of free chunks, and a total size and
136 // count that includes all three
138 class ChunkManager VALUE_OBJ_CLASS_SPEC {
140 // Free list of chunks of different sizes.
141 // SmallChunk
142 // MediumChunk
143 // HumongousChunk
144 ChunkList _free_chunks[NumberOfFreeLists];
146 // HumongousChunk
147 ChunkTreeDictionary _humongous_dictionary;
149 // ChunkManager in all lists of this type
150 size_t _free_chunks_total;
151 size_t _free_chunks_count;
153 void dec_free_chunks_total(size_t v) {
154 assert(_free_chunks_count > 0 &&
155 _free_chunks_total > 0,
156 "About to go negative");
157 Atomic::add_ptr(-1, &_free_chunks_count);
158 jlong minus_v = (jlong) - (jlong) v;
159 Atomic::add_ptr(minus_v, &_free_chunks_total);
160 }
162 // Debug support
164 size_t sum_free_chunks();
165 size_t sum_free_chunks_count();
167 void locked_verify_free_chunks_total();
168 void slow_locked_verify_free_chunks_total() {
169 if (metaspace_slow_verify) {
170 locked_verify_free_chunks_total();
171 }
172 }
173 void locked_verify_free_chunks_count();
174 void slow_locked_verify_free_chunks_count() {
175 if (metaspace_slow_verify) {
176 locked_verify_free_chunks_count();
177 }
178 }
179 void verify_free_chunks_count();
181 public:
183 ChunkManager() : _free_chunks_total(0), _free_chunks_count(0) {}
185 // add or delete (return) a chunk to the global freelist.
186 Metachunk* chunk_freelist_allocate(size_t word_size);
187 void chunk_freelist_deallocate(Metachunk* chunk);
189 // Total of the space in the free chunks list
190 size_t free_chunks_total();
191 size_t free_chunks_total_in_bytes();
193 // Number of chunks in the free chunks list
194 size_t free_chunks_count();
196 void inc_free_chunks_total(size_t v, size_t count = 1) {
197 Atomic::add_ptr(count, &_free_chunks_count);
198 Atomic::add_ptr(v, &_free_chunks_total);
199 }
200 ChunkList* free_medium_chunks() { return &_free_chunks[1]; }
201 ChunkList* free_small_chunks() { return &_free_chunks[0]; }
202 ChunkTreeDictionary* humongous_dictionary() {
203 return &_humongous_dictionary;
204 }
206 ChunkList* free_chunks(ChunkIndex index);
208 // Returns the list for the given chunk word size.
209 ChunkList* find_free_chunks_list(size_t word_size);
211 // Add and remove from a list by size. Selects
212 // list based on size of chunk.
213 void free_chunks_put(Metachunk* chuck);
214 Metachunk* free_chunks_get(size_t chunk_word_size);
216 // Debug support
217 void verify();
218 void slow_verify() {
219 if (metaspace_slow_verify) {
220 verify();
221 }
222 }
223 void locked_verify();
224 void slow_locked_verify() {
225 if (metaspace_slow_verify) {
226 locked_verify();
227 }
228 }
229 void verify_free_chunks_total();
231 void locked_print_free_chunks(outputStream* st);
232 void locked_print_sum_free_chunks(outputStream* st);
234 void print_on(outputStream* st);
235 };
238 // Used to manage the free list of Metablocks (a block corresponds
239 // to the allocation of a quantum of metadata).
240 class BlockFreelist VALUE_OBJ_CLASS_SPEC {
241 BlockTreeDictionary* _dictionary;
242 static Metablock* initialize_free_chunk(MetaWord* p, size_t word_size);
244 // Accessors
245 BlockTreeDictionary* dictionary() const { return _dictionary; }
247 public:
248 BlockFreelist();
249 ~BlockFreelist();
251 // Get and return a block to the free list
252 MetaWord* get_block(size_t word_size);
253 void return_block(MetaWord* p, size_t word_size);
255 size_t total_size() {
256 if (dictionary() == NULL) {
257 return 0;
258 } else {
259 return dictionary()->total_size();
260 }
261 }
263 void print_on(outputStream* st) const;
264 };
266 class VirtualSpaceNode : public CHeapObj<mtClass> {
267 friend class VirtualSpaceList;
269 // Link to next VirtualSpaceNode
270 VirtualSpaceNode* _next;
272 // total in the VirtualSpace
273 MemRegion _reserved;
274 ReservedSpace _rs;
275 VirtualSpace _virtual_space;
276 MetaWord* _top;
278 // Convenience functions for logical bottom and end
279 MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); }
280 MetaWord* end() const { return (MetaWord*) _virtual_space.high(); }
282 // Convenience functions to access the _virtual_space
283 char* low() const { return virtual_space()->low(); }
284 char* high() const { return virtual_space()->high(); }
286 public:
288 VirtualSpaceNode(size_t byte_size);
289 VirtualSpaceNode(ReservedSpace rs) : _top(NULL), _next(NULL), _rs(rs) {}
290 ~VirtualSpaceNode();
292 // address of next available space in _virtual_space;
293 // Accessors
294 VirtualSpaceNode* next() { return _next; }
295 void set_next(VirtualSpaceNode* v) { _next = v; }
297 void set_reserved(MemRegion const v) { _reserved = v; }
298 void set_top(MetaWord* v) { _top = v; }
300 // Accessors
301 MemRegion* reserved() { return &_reserved; }
302 VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; }
304 // Returns true if "word_size" is available in the virtual space
305 bool is_available(size_t word_size) { return _top + word_size <= end(); }
307 MetaWord* top() const { return _top; }
308 void inc_top(size_t word_size) { _top += word_size; }
310 // used and capacity in this single entry in the list
311 size_t used_words_in_vs() const;
312 size_t capacity_words_in_vs() const;
314 bool initialize();
316 // get space from the virtual space
317 Metachunk* take_from_committed(size_t chunk_word_size);
319 // Allocate a chunk from the virtual space and return it.
320 Metachunk* get_chunk_vs(size_t chunk_word_size);
321 Metachunk* get_chunk_vs_with_expand(size_t chunk_word_size);
323 // Expands/shrinks the committed space in a virtual space. Delegates
324 // to Virtualspace
325 bool expand_by(size_t words, bool pre_touch = false);
326 bool shrink_by(size_t words);
328 // Debug support
329 static void verify_virtual_space_total();
330 static void verify_virtual_space_count();
331 void mangle();
333 void print_on(outputStream* st) const;
334 };
336 // byte_size is the size of the associated virtualspace.
337 VirtualSpaceNode::VirtualSpaceNode(size_t byte_size) : _top(NULL), _next(NULL), _rs(0) {
338 // This allocates memory with mmap. For DumpSharedspaces, allocate the
339 // space at low memory so that other shared images don't conflict.
340 // This is the same address as memory needed for UseCompressedOops but
341 // compressed oops don't work with CDS (offsets in metadata are wrong), so
342 // borrow the same address.
343 if (DumpSharedSpaces) {
344 char* shared_base = (char*)HeapBaseMinAddress;
345 _rs = ReservedSpace(byte_size, 0, false, shared_base, 0);
346 if (_rs.is_reserved()) {
347 assert(_rs.base() == shared_base, "should match");
348 } else {
349 // If we are dumping the heap, then allocate a wasted block of address
350 // space in order to push the heap to a lower address. This extra
351 // address range allows for other (or larger) libraries to be loaded
352 // without them occupying the space required for the shared spaces.
353 uintx reserved = 0;
354 uintx block_size = 64*1024*1024;
355 while (reserved < SharedDummyBlockSize) {
356 char* dummy = os::reserve_memory(block_size);
357 reserved += block_size;
358 }
359 _rs = ReservedSpace(byte_size);
360 }
361 MetaspaceShared::set_shared_rs(&_rs);
362 } else {
363 _rs = ReservedSpace(byte_size);
364 }
366 MemTracker::record_virtual_memory_type((address)_rs.base(), mtClass);
367 }
369 // List of VirtualSpaces for metadata allocation.
370 // It has a _next link for singly linked list and a MemRegion
371 // for total space in the VirtualSpace.
372 class VirtualSpaceList : public CHeapObj<mtClass> {
373 friend class VirtualSpaceNode;
375 enum VirtualSpaceSizes {
376 VirtualSpaceSize = 256 * K
377 };
379 // Global list of virtual spaces
380 // Head of the list
381 VirtualSpaceNode* _virtual_space_list;
382 // virtual space currently being used for allocations
383 VirtualSpaceNode* _current_virtual_space;
384 // Free chunk list for all other metadata
385 ChunkManager _chunk_manager;
387 // Can this virtual list allocate >1 spaces? Also, used to determine
388 // whether to allocate unlimited small chunks in this virtual space
389 bool _is_class;
390 bool can_grow() const { return !is_class() || !UseCompressedKlassPointers; }
392 // Sum of space in all virtual spaces and number of virtual spaces
393 size_t _virtual_space_total;
394 size_t _virtual_space_count;
396 ~VirtualSpaceList();
398 VirtualSpaceNode* virtual_space_list() const { return _virtual_space_list; }
400 void set_virtual_space_list(VirtualSpaceNode* v) {
401 _virtual_space_list = v;
402 }
403 void set_current_virtual_space(VirtualSpaceNode* v) {
404 _current_virtual_space = v;
405 }
407 void link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size);
409 // Get another virtual space and add it to the list. This
410 // is typically prompted by a failed attempt to allocate a chunk
411 // and is typically followed by the allocation of a chunk.
412 bool grow_vs(size_t vs_word_size);
414 public:
415 VirtualSpaceList(size_t word_size);
416 VirtualSpaceList(ReservedSpace rs);
418 Metachunk* get_new_chunk(size_t word_size, size_t grow_chunks_by_words);
420 VirtualSpaceNode* current_virtual_space() {
421 return _current_virtual_space;
422 }
424 ChunkManager* chunk_manager() { return &_chunk_manager; }
425 bool is_class() const { return _is_class; }
427 // Allocate the first virtualspace.
428 void initialize(size_t word_size);
430 size_t virtual_space_total() { return _virtual_space_total; }
431 void inc_virtual_space_total(size_t v) {
432 Atomic::add_ptr(v, &_virtual_space_total);
433 }
435 size_t virtual_space_count() { return _virtual_space_count; }
436 void inc_virtual_space_count() {
437 Atomic::inc_ptr(&_virtual_space_count);
438 }
440 // Used and capacity in the entire list of virtual spaces.
441 // These are global values shared by all Metaspaces
442 size_t capacity_words_sum();
443 size_t capacity_bytes_sum() { return capacity_words_sum() * BytesPerWord; }
444 size_t used_words_sum();
445 size_t used_bytes_sum() { return used_words_sum() * BytesPerWord; }
447 bool contains(const void *ptr);
449 void print_on(outputStream* st) const;
451 class VirtualSpaceListIterator : public StackObj {
452 VirtualSpaceNode* _virtual_spaces;
453 public:
454 VirtualSpaceListIterator(VirtualSpaceNode* virtual_spaces) :
455 _virtual_spaces(virtual_spaces) {}
457 bool repeat() {
458 return _virtual_spaces != NULL;
459 }
461 VirtualSpaceNode* get_next() {
462 VirtualSpaceNode* result = _virtual_spaces;
463 if (_virtual_spaces != NULL) {
464 _virtual_spaces = _virtual_spaces->next();
465 }
466 return result;
467 }
468 };
469 };
471 class Metadebug : AllStatic {
472 // Debugging support for Metaspaces
473 static int _deallocate_block_a_lot_count;
474 static int _deallocate_chunk_a_lot_count;
475 static int _allocation_fail_alot_count;
477 public:
478 static int deallocate_block_a_lot_count() {
479 return _deallocate_block_a_lot_count;
480 }
481 static void set_deallocate_block_a_lot_count(int v) {
482 _deallocate_block_a_lot_count = v;
483 }
484 static void inc_deallocate_block_a_lot_count() {
485 _deallocate_block_a_lot_count++;
486 }
487 static int deallocate_chunk_a_lot_count() {
488 return _deallocate_chunk_a_lot_count;
489 }
490 static void reset_deallocate_chunk_a_lot_count() {
491 _deallocate_chunk_a_lot_count = 1;
492 }
493 static void inc_deallocate_chunk_a_lot_count() {
494 _deallocate_chunk_a_lot_count++;
495 }
497 static void init_allocation_fail_alot_count();
498 #ifdef ASSERT
499 static bool test_metadata_failure();
500 #endif
502 static void deallocate_chunk_a_lot(SpaceManager* sm,
503 size_t chunk_word_size);
504 static void deallocate_block_a_lot(SpaceManager* sm,
505 size_t chunk_word_size);
507 };
509 int Metadebug::_deallocate_block_a_lot_count = 0;
510 int Metadebug::_deallocate_chunk_a_lot_count = 0;
511 int Metadebug::_allocation_fail_alot_count = 0;
513 // SpaceManager - used by Metaspace to handle allocations
514 class SpaceManager : public CHeapObj<mtClass> {
515 friend class Metaspace;
516 friend class Metadebug;
518 private:
519 // protects allocations and contains.
520 Mutex* const _lock;
522 // List of chunks in use by this SpaceManager. Allocations
523 // are done from the current chunk. The list is used for deallocating
524 // chunks when the SpaceManager is freed.
525 Metachunk* _chunks_in_use[NumberOfInUseLists];
526 Metachunk* _current_chunk;
528 // Virtual space where allocation comes from.
529 VirtualSpaceList* _vs_list;
531 // Number of small chunks to allocate to a manager
532 // If class space manager, small chunks are unlimited
533 static uint const _small_chunk_limit;
534 bool has_small_chunk_limit() { return !vs_list()->is_class(); }
536 // Sum of all space in allocated chunks
537 size_t _allocation_total;
539 // Free lists of blocks are per SpaceManager since they
540 // are assumed to be in chunks in use by the SpaceManager
541 // and all chunks in use by a SpaceManager are freed when
542 // the class loader using the SpaceManager is collected.
543 BlockFreelist _block_freelists;
545 // protects virtualspace and chunk expansions
546 static const char* _expand_lock_name;
547 static const int _expand_lock_rank;
548 static Mutex* const _expand_lock;
550 // Accessors
551 Metachunk* chunks_in_use(ChunkIndex index) const { return _chunks_in_use[index]; }
552 void set_chunks_in_use(ChunkIndex index, Metachunk* v) { _chunks_in_use[index] = v; }
554 BlockFreelist* block_freelists() const {
555 return (BlockFreelist*) &_block_freelists;
556 }
558 VirtualSpaceList* vs_list() const { return _vs_list; }
560 Metachunk* current_chunk() const { return _current_chunk; }
561 void set_current_chunk(Metachunk* v) {
562 _current_chunk = v;
563 }
565 Metachunk* find_current_chunk(size_t word_size);
567 // Add chunk to the list of chunks in use
568 void add_chunk(Metachunk* v, bool make_current);
570 Mutex* lock() const { return _lock; }
572 public:
573 SpaceManager(Mutex* lock, VirtualSpaceList* vs_list);
574 ~SpaceManager();
576 enum ChunkSizes { // in words.
577 SmallChunk = 512,
578 MediumChunk = 8 * K,
579 MediumChunkBunch = 4 * MediumChunk
580 };
582 // Accessors
583 size_t allocation_total() const { return _allocation_total; }
584 void inc_allocation_total(size_t v) { Atomic::add_ptr(v, &_allocation_total); }
585 static bool is_humongous(size_t word_size) { return word_size > MediumChunk; }
587 static Mutex* expand_lock() { return _expand_lock; }
589 size_t sum_capacity_in_chunks_in_use() const;
590 size_t sum_used_in_chunks_in_use() const;
591 size_t sum_free_in_chunks_in_use() const;
592 size_t sum_waste_in_chunks_in_use() const;
593 size_t sum_waste_in_chunks_in_use(ChunkIndex index ) const;
595 size_t sum_count_in_chunks_in_use();
596 size_t sum_count_in_chunks_in_use(ChunkIndex i);
598 // Block allocation and deallocation.
599 // Allocates a block from the current chunk
600 MetaWord* allocate(size_t word_size);
602 // Helper for allocations
603 MetaWord* allocate_work(size_t word_size);
605 // Returns a block to the per manager freelist
606 void deallocate(MetaWord* p, size_t word_size);
608 // Based on the allocation size and a minimum chunk size,
609 // returned chunk size (for expanding space for chunk allocation).
610 size_t calc_chunk_size(size_t allocation_word_size);
612 // Called when an allocation from the current chunk fails.
613 // Gets a new chunk (may require getting a new virtual space),
614 // and allocates from that chunk.
615 MetaWord* grow_and_allocate(size_t word_size);
617 // debugging support.
619 void dump(outputStream* const out) const;
620 void print_on(outputStream* st) const;
621 void locked_print_chunks_in_use_on(outputStream* st) const;
623 void verify();
624 #ifdef ASSERT
625 void mangle_freed_chunks();
626 void verify_allocation_total();
627 #endif
628 };
630 uint const SpaceManager::_small_chunk_limit = 4;
634 const char* SpaceManager::_expand_lock_name =
635 "SpaceManager chunk allocation lock";
636 const int SpaceManager::_expand_lock_rank = Monitor::leaf - 1;
637 Mutex* const SpaceManager::_expand_lock =
638 new Mutex(SpaceManager::_expand_lock_rank,
639 SpaceManager::_expand_lock_name,
640 Mutex::_allow_vm_block_flag);
642 size_t Metachunk::_overhead =
643 Chunk::aligned_overhead_size(sizeof(Metachunk)) / BytesPerWord;
645 // New blocks returned by the Metaspace are zero initialized.
646 // We should fix the constructors to not assume this instead.
647 Metablock* Metablock::initialize(MetaWord* p, size_t word_size) {
648 if (p == NULL) {
649 return NULL;
650 }
652 Metablock* result = (Metablock*) p;
654 // Clear the memory
655 Copy::fill_to_aligned_words((HeapWord*)result, word_size);
656 #ifdef ASSERT
657 result->set_word_size(word_size);
658 #endif
659 return result;
660 }
662 // Metachunk methods
664 Metachunk* Metachunk::initialize(MetaWord* ptr, size_t word_size) {
665 // Set bottom, top, and end. Allow space for the Metachunk itself
666 Metachunk* chunk = (Metachunk*) ptr;
668 MetaWord* chunk_bottom = ptr + _overhead;
669 chunk->set_bottom(ptr);
670 chunk->set_top(chunk_bottom);
671 MetaWord* chunk_end = ptr + word_size;
672 assert(chunk_end > chunk_bottom, "Chunk must be too small");
673 chunk->set_end(chunk_end);
674 chunk->set_next(NULL);
675 chunk->set_word_size(word_size);
676 #ifdef ASSERT
677 size_t data_word_size = pointer_delta(chunk_end, chunk_bottom, sizeof(MetaWord));
678 Copy::fill_to_words((HeapWord*) chunk_bottom, data_word_size, metadata_chunk_initialize);
679 #endif
680 return chunk;
681 }
684 MetaWord* Metachunk::allocate(size_t word_size) {
685 MetaWord* result = NULL;
686 // If available, bump the pointer to allocate.
687 if (free_word_size() >= word_size) {
688 result = _top;
689 _top = _top + word_size;
690 }
691 return result;
692 }
694 // _bottom points to the start of the chunk including the overhead.
695 size_t Metachunk::used_word_size() {
696 return pointer_delta(_top, _bottom, sizeof(MetaWord));
697 }
699 size_t Metachunk::free_word_size() {
700 return pointer_delta(_end, _top, sizeof(MetaWord));
701 }
703 size_t Metachunk::capacity_word_size() {
704 return pointer_delta(_end, _bottom, sizeof(MetaWord));
705 }
707 void Metachunk::print_on(outputStream* st) const {
708 st->print_cr("Metachunk:"
709 " bottom " PTR_FORMAT " top " PTR_FORMAT
710 " end " PTR_FORMAT " size " SIZE_FORMAT,
711 bottom(), top(), end(), word_size());
712 }
714 #ifdef ASSERT
715 void Metachunk::mangle() {
716 // Mangle the payload of the chunk and not the links that
717 // maintain list of chunks.
718 HeapWord* start = (HeapWord*)(bottom() + overhead());
719 size_t word_size = capacity_word_size() - overhead();
720 Copy::fill_to_words(start, word_size, metadata_chunk_initialize);
721 }
722 #endif // ASSERT
724 void Metachunk::verify() {
725 #ifdef ASSERT
726 // Cannot walk through the blocks unless the blocks have
727 // headers with sizes.
728 assert(_bottom <= _top &&
729 _top <= _end,
730 "Chunk has been smashed");
731 assert(SpaceManager::is_humongous(_word_size) ||
732 _word_size == SpaceManager::MediumChunk ||
733 _word_size == SpaceManager::SmallChunk,
734 "Chunk size is wrong");
735 #endif
736 return;
737 }
739 // BlockFreelist methods
741 BlockFreelist::BlockFreelist() : _dictionary(NULL) {}
743 BlockFreelist::~BlockFreelist() {
744 if (_dictionary != NULL) {
745 if (Verbose && TraceMetadataChunkAllocation) {
746 _dictionary->print_free_lists(gclog_or_tty);
747 }
748 delete _dictionary;
749 }
750 }
752 Metablock* BlockFreelist::initialize_free_chunk(MetaWord* p, size_t word_size) {
753 Metablock* block = (Metablock*) p;
754 block->set_word_size(word_size);
755 block->set_prev(NULL);
756 block->set_next(NULL);
758 return block;
759 }
761 void BlockFreelist::return_block(MetaWord* p, size_t word_size) {
762 Metablock* free_chunk = initialize_free_chunk(p, word_size);
763 if (dictionary() == NULL) {
764 _dictionary = new BlockTreeDictionary();
765 }
766 dictionary()->return_chunk(free_chunk);
767 }
769 MetaWord* BlockFreelist::get_block(size_t word_size) {
770 if (dictionary() == NULL) {
771 return NULL;
772 }
774 if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
775 // Dark matter. Too small for dictionary.
776 return NULL;
777 }
779 Metablock* free_block =
780 dictionary()->get_chunk(word_size, FreeBlockDictionary<Metablock>::exactly);
781 if (free_block == NULL) {
782 return NULL;
783 }
785 return (MetaWord*) free_block;
786 }
788 void BlockFreelist::print_on(outputStream* st) const {
789 if (dictionary() == NULL) {
790 return;
791 }
792 dictionary()->print_free_lists(st);
793 }
795 // VirtualSpaceNode methods
797 VirtualSpaceNode::~VirtualSpaceNode() {
798 _rs.release();
799 }
801 size_t VirtualSpaceNode::used_words_in_vs() const {
802 return pointer_delta(top(), bottom(), sizeof(MetaWord));
803 }
805 // Space committed in the VirtualSpace
806 size_t VirtualSpaceNode::capacity_words_in_vs() const {
807 return pointer_delta(end(), bottom(), sizeof(MetaWord));
808 }
811 // Allocates the chunk from the virtual space only.
812 // This interface is also used internally for debugging. Not all
813 // chunks removed here are necessarily used for allocation.
814 Metachunk* VirtualSpaceNode::take_from_committed(size_t chunk_word_size) {
815 // Bottom of the new chunk
816 MetaWord* chunk_limit = top();
817 assert(chunk_limit != NULL, "Not safe to call this method");
819 if (!is_available(chunk_word_size)) {
820 if (TraceMetadataChunkAllocation) {
821 tty->print("VirtualSpaceNode::take_from_committed() not available %d words ", chunk_word_size);
822 // Dump some information about the virtual space that is nearly full
823 print_on(tty);
824 }
825 return NULL;
826 }
828 // Take the space (bump top on the current virtual space).
829 inc_top(chunk_word_size);
831 // Point the chunk at the space
832 Metachunk* result = Metachunk::initialize(chunk_limit, chunk_word_size);
833 return result;
834 }
837 // Expand the virtual space (commit more of the reserved space)
838 bool VirtualSpaceNode::expand_by(size_t words, bool pre_touch) {
839 size_t bytes = words * BytesPerWord;
840 bool result = virtual_space()->expand_by(bytes, pre_touch);
841 if (TraceMetavirtualspaceAllocation && !result) {
842 gclog_or_tty->print_cr("VirtualSpaceNode::expand_by() failed "
843 "for byte size " SIZE_FORMAT, bytes);
844 virtual_space()->print();
845 }
846 return result;
847 }
849 // Shrink the virtual space (commit more of the reserved space)
850 bool VirtualSpaceNode::shrink_by(size_t words) {
851 size_t bytes = words * BytesPerWord;
852 virtual_space()->shrink_by(bytes);
853 return true;
854 }
856 // Add another chunk to the chunk list.
858 Metachunk* VirtualSpaceNode::get_chunk_vs(size_t chunk_word_size) {
859 assert_lock_strong(SpaceManager::expand_lock());
860 Metachunk* result = NULL;
862 return take_from_committed(chunk_word_size);
863 }
865 Metachunk* VirtualSpaceNode::get_chunk_vs_with_expand(size_t chunk_word_size) {
866 assert_lock_strong(SpaceManager::expand_lock());
868 Metachunk* new_chunk = get_chunk_vs(chunk_word_size);
870 if (new_chunk == NULL) {
871 // Only a small part of the virtualspace is committed when first
872 // allocated so committing more here can be expected.
873 size_t page_size_words = os::vm_page_size() / BytesPerWord;
874 size_t aligned_expand_vs_by_words = align_size_up(chunk_word_size,
875 page_size_words);
876 expand_by(aligned_expand_vs_by_words, false);
877 new_chunk = get_chunk_vs(chunk_word_size);
878 }
879 return new_chunk;
880 }
882 bool VirtualSpaceNode::initialize() {
884 if (!_rs.is_reserved()) {
885 return false;
886 }
888 // Commit only 1 page instead of the whole reserved space _rs.size()
889 size_t committed_byte_size = os::vm_page_size();
890 bool result = virtual_space()->initialize(_rs, committed_byte_size);
891 if (result) {
892 set_top((MetaWord*)virtual_space()->low());
893 set_reserved(MemRegion((HeapWord*)_rs.base(),
894 (HeapWord*)(_rs.base() + _rs.size())));
896 assert(reserved()->start() == (HeapWord*) _rs.base(),
897 err_msg("Reserved start was not set properly " PTR_FORMAT
898 " != " PTR_FORMAT, reserved()->start(), _rs.base()));
899 assert(reserved()->word_size() == _rs.size() / BytesPerWord,
900 err_msg("Reserved size was not set properly " SIZE_FORMAT
901 " != " SIZE_FORMAT, reserved()->word_size(),
902 _rs.size() / BytesPerWord));
903 }
905 return result;
906 }
908 void VirtualSpaceNode::print_on(outputStream* st) const {
909 size_t used = used_words_in_vs();
910 size_t capacity = capacity_words_in_vs();
911 VirtualSpace* vs = virtual_space();
912 st->print_cr(" space @ " PTR_FORMAT " " SIZE_FORMAT "K, %3d%% used "
913 "[" PTR_FORMAT ", " PTR_FORMAT ", "
914 PTR_FORMAT ", " PTR_FORMAT ")",
915 vs, capacity / K, used * 100 / capacity,
916 bottom(), top(), end(),
917 vs->high_boundary());
918 }
920 void VirtualSpaceNode::mangle() {
921 size_t word_size = capacity_words_in_vs();
922 Copy::fill_to_words((HeapWord*) low(), word_size, 0xf1f1f1f1);
923 }
925 // VirtualSpaceList methods
926 // Space allocated from the VirtualSpace
928 VirtualSpaceList::~VirtualSpaceList() {
929 VirtualSpaceListIterator iter(virtual_space_list());
930 while (iter.repeat()) {
931 VirtualSpaceNode* vsl = iter.get_next();
932 delete vsl;
933 }
934 }
936 size_t VirtualSpaceList::used_words_sum() {
937 size_t allocated_by_vs = 0;
938 VirtualSpaceListIterator iter(virtual_space_list());
939 while (iter.repeat()) {
940 VirtualSpaceNode* vsl = iter.get_next();
941 // Sum used region [bottom, top) in each virtualspace
942 allocated_by_vs += vsl->used_words_in_vs();
943 }
944 assert(allocated_by_vs >= chunk_manager()->free_chunks_total(),
945 err_msg("Total in free chunks " SIZE_FORMAT
946 " greater than total from virtual_spaces " SIZE_FORMAT,
947 allocated_by_vs, chunk_manager()->free_chunks_total()));
948 size_t used =
949 allocated_by_vs - chunk_manager()->free_chunks_total();
950 return used;
951 }
953 // Space available in all MetadataVirtualspaces allocated
954 // for metadata. This is the upper limit on the capacity
955 // of chunks allocated out of all the MetadataVirtualspaces.
956 size_t VirtualSpaceList::capacity_words_sum() {
957 size_t capacity = 0;
958 VirtualSpaceListIterator iter(virtual_space_list());
959 while (iter.repeat()) {
960 VirtualSpaceNode* vsl = iter.get_next();
961 capacity += vsl->capacity_words_in_vs();
962 }
963 return capacity;
964 }
966 VirtualSpaceList::VirtualSpaceList(size_t word_size ) :
967 _is_class(false),
968 _virtual_space_list(NULL),
969 _current_virtual_space(NULL),
970 _virtual_space_total(0),
971 _virtual_space_count(0) {
972 MutexLockerEx cl(SpaceManager::expand_lock(),
973 Mutex::_no_safepoint_check_flag);
974 bool initialization_succeeded = grow_vs(word_size);
976 assert(initialization_succeeded,
977 " VirtualSpaceList initialization should not fail");
978 }
980 VirtualSpaceList::VirtualSpaceList(ReservedSpace rs) :
981 _is_class(true),
982 _virtual_space_list(NULL),
983 _current_virtual_space(NULL),
984 _virtual_space_total(0),
985 _virtual_space_count(0) {
986 MutexLockerEx cl(SpaceManager::expand_lock(),
987 Mutex::_no_safepoint_check_flag);
988 VirtualSpaceNode* class_entry = new VirtualSpaceNode(rs);
989 bool succeeded = class_entry->initialize();
990 assert(succeeded, " VirtualSpaceList initialization should not fail");
991 link_vs(class_entry, rs.size()/BytesPerWord);
992 }
994 // Allocate another meta virtual space and add it to the list.
995 bool VirtualSpaceList::grow_vs(size_t vs_word_size) {
996 assert_lock_strong(SpaceManager::expand_lock());
997 if (vs_word_size == 0) {
998 return false;
999 }
1000 // Reserve the space
1001 size_t vs_byte_size = vs_word_size * BytesPerWord;
1002 assert(vs_byte_size % os::vm_page_size() == 0, "Not aligned");
1004 // Allocate the meta virtual space and initialize it.
1005 VirtualSpaceNode* new_entry = new VirtualSpaceNode(vs_byte_size);
1006 if (!new_entry->initialize()) {
1007 delete new_entry;
1008 return false;
1009 } else {
1010 link_vs(new_entry, vs_word_size);
1011 return true;
1012 }
1013 }
1015 void VirtualSpaceList::link_vs(VirtualSpaceNode* new_entry, size_t vs_word_size) {
1016 if (virtual_space_list() == NULL) {
1017 set_virtual_space_list(new_entry);
1018 } else {
1019 current_virtual_space()->set_next(new_entry);
1020 }
1021 set_current_virtual_space(new_entry);
1022 inc_virtual_space_total(vs_word_size);
1023 inc_virtual_space_count();
1024 #ifdef ASSERT
1025 new_entry->mangle();
1026 #endif
1027 if (TraceMetavirtualspaceAllocation && Verbose) {
1028 VirtualSpaceNode* vsl = current_virtual_space();
1029 vsl->print_on(tty);
1030 }
1031 }
1033 Metachunk* VirtualSpaceList::get_new_chunk(size_t word_size,
1034 size_t grow_chunks_by_words) {
1036 // Get a chunk from the chunk freelist
1037 Metachunk* next = chunk_manager()->chunk_freelist_allocate(grow_chunks_by_words);
1039 // Allocate a chunk out of the current virtual space.
1040 if (next == NULL) {
1041 next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1042 }
1044 if (next == NULL) {
1045 // Not enough room in current virtual space. Try to commit
1046 // more space.
1047 size_t expand_vs_by_words = MAX2((size_t)SpaceManager::MediumChunkBunch,
1048 grow_chunks_by_words);
1049 size_t page_size_words = os::vm_page_size() / BytesPerWord;
1050 size_t aligned_expand_vs_by_words = align_size_up(expand_vs_by_words,
1051 page_size_words);
1052 bool vs_expanded =
1053 current_virtual_space()->expand_by(aligned_expand_vs_by_words, false);
1054 if (!vs_expanded) {
1055 // Should the capacity of the metaspaces be expanded for
1056 // this allocation? If it's the virtual space for classes and is
1057 // being used for CompressedHeaders, don't allocate a new virtualspace.
1058 if (can_grow() && MetaspaceGC::should_expand(this, word_size)) {
1059 // Get another virtual space.
1060 size_t grow_vs_words =
1061 MAX2((size_t)VirtualSpaceSize, aligned_expand_vs_by_words);
1062 if (grow_vs(grow_vs_words)) {
1063 // Got it. It's on the list now. Get a chunk from it.
1064 next = current_virtual_space()->get_chunk_vs_with_expand(grow_chunks_by_words);
1065 }
1066 if (TraceMetadataHumongousAllocation && SpaceManager::is_humongous(word_size)) {
1067 gclog_or_tty->print_cr(" aligned_expand_vs_by_words " PTR_FORMAT,
1068 aligned_expand_vs_by_words);
1069 gclog_or_tty->print_cr(" grow_vs_words " PTR_FORMAT,
1070 grow_vs_words);
1071 }
1072 } else {
1073 // Allocation will fail and induce a GC
1074 if (TraceMetadataChunkAllocation && Verbose) {
1075 gclog_or_tty->print_cr("VirtualSpaceList::get_new_chunk():"
1076 " Fail instead of expand the metaspace");
1077 }
1078 }
1079 } else {
1080 // The virtual space expanded, get a new chunk
1081 next = current_virtual_space()->get_chunk_vs(grow_chunks_by_words);
1082 assert(next != NULL, "Just expanded, should succeed");
1083 }
1084 }
1086 return next;
1087 }
1089 void VirtualSpaceList::print_on(outputStream* st) const {
1090 if (TraceMetadataChunkAllocation && Verbose) {
1091 VirtualSpaceListIterator iter(virtual_space_list());
1092 while (iter.repeat()) {
1093 VirtualSpaceNode* node = iter.get_next();
1094 node->print_on(st);
1095 }
1096 }
1097 }
1099 #ifndef PRODUCT
1100 bool VirtualSpaceList::contains(const void *ptr) {
1101 VirtualSpaceNode* list = virtual_space_list();
1102 VirtualSpaceListIterator iter(list);
1103 while (iter.repeat()) {
1104 VirtualSpaceNode* node = iter.get_next();
1105 if (node->reserved()->contains(ptr)) {
1106 return true;
1107 }
1108 }
1109 return false;
1110 }
1111 #endif // PRODUCT
1114 // MetaspaceGC methods
1116 // VM_CollectForMetadataAllocation is the vm operation used to GC.
1117 // Within the VM operation after the GC the attempt to allocate the metadata
1118 // should succeed. If the GC did not free enough space for the metaspace
1119 // allocation, the HWM is increased so that another virtualspace will be
1120 // allocated for the metadata. With perm gen the increase in the perm
1121 // gen had bounds, MinMetaspaceExpansion and MaxMetaspaceExpansion. The
1122 // metaspace policy uses those as the small and large steps for the HWM.
1123 //
1124 // After the GC the compute_new_size() for MetaspaceGC is called to
1125 // resize the capacity of the metaspaces. The current implementation
1126 // is based on the flags MinHeapFreeRatio and MaxHeapFreeRatio used
1127 // to resize the Java heap by some GC's. New flags can be implemented
1128 // if really needed. MinHeapFreeRatio is used to calculate how much
1129 // free space is desirable in the metaspace capacity to decide how much
1130 // to increase the HWM. MaxHeapFreeRatio is used to decide how much
1131 // free space is desirable in the metaspace capacity before decreasing
1132 // the HWM.
1134 // Calculate the amount to increase the high water mark (HWM).
1135 // Increase by a minimum amount (MinMetaspaceExpansion) so that
1136 // another expansion is not requested too soon. If that is not
1137 // enough to satisfy the allocation (i.e. big enough for a word_size
1138 // allocation), increase by MaxMetaspaceExpansion. If that is still
1139 // not enough, expand by the size of the allocation (word_size) plus
1140 // some.
1141 size_t MetaspaceGC::delta_capacity_until_GC(size_t word_size) {
1142 size_t before_inc = MetaspaceGC::capacity_until_GC();
1143 size_t min_delta_words = MinMetaspaceExpansion / BytesPerWord;
1144 size_t max_delta_words = MaxMetaspaceExpansion / BytesPerWord;
1145 size_t page_size_words = os::vm_page_size() / BytesPerWord;
1146 size_t size_delta_words = align_size_up(word_size, page_size_words);
1147 size_t delta_words = MAX2(size_delta_words, min_delta_words);
1148 if (delta_words > min_delta_words) {
1149 // Don't want to hit the high water mark on the next
1150 // allocation so make the delta greater than just enough
1151 // for this allocation.
1152 delta_words = MAX2(delta_words, max_delta_words);
1153 if (delta_words > max_delta_words) {
1154 // This allocation is large but the next ones are probably not
1155 // so increase by the minimum.
1156 delta_words = delta_words + min_delta_words;
1157 }
1158 }
1159 return delta_words;
1160 }
1162 bool MetaspaceGC::should_expand(VirtualSpaceList* vsl, size_t word_size) {
1164 // Class virtual space should always be expanded. Call GC for the other
1165 // metadata virtual space.
1166 if (vsl == Metaspace::class_space_list()) return true;
1168 // If the user wants a limit, impose one.
1169 size_t max_metaspace_size_words = MaxMetaspaceSize / BytesPerWord;
1170 size_t metaspace_size_words = MetaspaceSize / BytesPerWord;
1171 if (!FLAG_IS_DEFAULT(MaxMetaspaceSize) &&
1172 vsl->capacity_words_sum() >= max_metaspace_size_words) {
1173 return false;
1174 }
1176 // If this is part of an allocation after a GC, expand
1177 // unconditionally.
1178 if(MetaspaceGC::expand_after_GC()) {
1179 return true;
1180 }
1182 // If the capacity is below the minimum capacity, allow the
1183 // expansion. Also set the high-water-mark (capacity_until_GC)
1184 // to that minimum capacity so that a GC will not be induced
1185 // until that minimum capacity is exceeded.
1186 if (vsl->capacity_words_sum() < metaspace_size_words ||
1187 capacity_until_GC() == 0) {
1188 set_capacity_until_GC(metaspace_size_words);
1189 return true;
1190 } else {
1191 if (vsl->capacity_words_sum() < capacity_until_GC()) {
1192 return true;
1193 } else {
1194 if (TraceMetadataChunkAllocation && Verbose) {
1195 gclog_or_tty->print_cr(" allocation request size " SIZE_FORMAT
1196 " capacity_until_GC " SIZE_FORMAT
1197 " capacity_words_sum " SIZE_FORMAT
1198 " used_words_sum " SIZE_FORMAT
1199 " free chunks " SIZE_FORMAT
1200 " free chunks count %d",
1201 word_size,
1202 capacity_until_GC(),
1203 vsl->capacity_words_sum(),
1204 vsl->used_words_sum(),
1205 vsl->chunk_manager()->free_chunks_total(),
1206 vsl->chunk_manager()->free_chunks_count());
1207 }
1208 return false;
1209 }
1210 }
1211 }
1213 // Variables are in bytes
1215 void MetaspaceGC::compute_new_size() {
1216 assert(_shrink_factor <= 100, "invalid shrink factor");
1217 uint current_shrink_factor = _shrink_factor;
1218 _shrink_factor = 0;
1220 VirtualSpaceList *vsl = Metaspace::space_list();
1222 size_t capacity_after_gc = vsl->capacity_bytes_sum();
1223 // Check to see if these two can be calculated without walking the CLDG
1224 size_t used_after_gc = vsl->used_bytes_sum();
1225 size_t capacity_until_GC = vsl->capacity_bytes_sum();
1226 size_t free_after_gc = capacity_until_GC - used_after_gc;
1228 const double minimum_free_percentage = MinHeapFreeRatio / 100.0;
1229 const double maximum_used_percentage = 1.0 - minimum_free_percentage;
1231 const double min_tmp = used_after_gc / maximum_used_percentage;
1232 size_t minimum_desired_capacity =
1233 (size_t)MIN2(min_tmp, double(max_uintx));
1234 // Don't shrink less than the initial generation size
1235 minimum_desired_capacity = MAX2(minimum_desired_capacity,
1236 MetaspaceSize);
1238 if (PrintGCDetails && Verbose) {
1239 const double free_percentage = ((double)free_after_gc) / capacity_until_GC;
1240 gclog_or_tty->print_cr("\nMetaspaceGC::compute_new_size: ");
1241 gclog_or_tty->print_cr(" "
1242 " minimum_free_percentage: %6.2f"
1243 " maximum_used_percentage: %6.2f",
1244 minimum_free_percentage,
1245 maximum_used_percentage);
1246 double d_free_after_gc = free_after_gc / (double) K;
1247 gclog_or_tty->print_cr(" "
1248 " free_after_gc : %6.1fK"
1249 " used_after_gc : %6.1fK"
1250 " capacity_after_gc : %6.1fK"
1251 " metaspace HWM : %6.1fK",
1252 free_after_gc / (double) K,
1253 used_after_gc / (double) K,
1254 capacity_after_gc / (double) K,
1255 capacity_until_GC / (double) K);
1256 gclog_or_tty->print_cr(" "
1257 " free_percentage: %6.2f",
1258 free_percentage);
1259 }
1262 if (capacity_until_GC < minimum_desired_capacity) {
1263 // If we have less capacity below the metaspace HWM, then
1264 // increment the HWM.
1265 size_t expand_bytes = minimum_desired_capacity - capacity_until_GC;
1266 // Don't expand unless it's significant
1267 if (expand_bytes >= MinMetaspaceExpansion) {
1268 size_t expand_words = expand_bytes / BytesPerWord;
1269 MetaspaceGC::inc_capacity_until_GC(expand_words);
1270 }
1271 if (PrintGCDetails && Verbose) {
1272 size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
1273 gclog_or_tty->print_cr(" expanding:"
1274 " minimum_desired_capacity: %6.1fK"
1275 " expand_words: %6.1fK"
1276 " MinMetaspaceExpansion: %6.1fK"
1277 " new metaspace HWM: %6.1fK",
1278 minimum_desired_capacity / (double) K,
1279 expand_bytes / (double) K,
1280 MinMetaspaceExpansion / (double) K,
1281 new_capacity_until_GC / (double) K);
1282 }
1283 return;
1284 }
1286 // No expansion, now see if we want to shrink
1287 size_t shrink_words = 0;
1288 // We would never want to shrink more than this
1289 size_t max_shrink_words = capacity_until_GC - minimum_desired_capacity;
1290 assert(max_shrink_words >= 0, err_msg("max_shrink_words " SIZE_FORMAT,
1291 max_shrink_words));
1293 // Should shrinking be considered?
1294 if (MaxHeapFreeRatio < 100) {
1295 const double maximum_free_percentage = MaxHeapFreeRatio / 100.0;
1296 const double minimum_used_percentage = 1.0 - maximum_free_percentage;
1297 const double max_tmp = used_after_gc / minimum_used_percentage;
1298 size_t maximum_desired_capacity = (size_t)MIN2(max_tmp, double(max_uintx));
1299 maximum_desired_capacity = MAX2(maximum_desired_capacity,
1300 MetaspaceSize);
1301 if (PrintGC && Verbose) {
1302 gclog_or_tty->print_cr(" "
1303 " maximum_free_percentage: %6.2f"
1304 " minimum_used_percentage: %6.2f",
1305 maximum_free_percentage,
1306 minimum_used_percentage);
1307 gclog_or_tty->print_cr(" "
1308 " capacity_until_GC: %6.1fK"
1309 " minimum_desired_capacity: %6.1fK"
1310 " maximum_desired_capacity: %6.1fK",
1311 capacity_until_GC / (double) K,
1312 minimum_desired_capacity / (double) K,
1313 maximum_desired_capacity / (double) K);
1314 }
1316 assert(minimum_desired_capacity <= maximum_desired_capacity,
1317 "sanity check");
1319 if (capacity_until_GC > maximum_desired_capacity) {
1320 // Capacity too large, compute shrinking size
1321 shrink_words = capacity_until_GC - maximum_desired_capacity;
1322 // We don't want shrink all the way back to initSize if people call
1323 // System.gc(), because some programs do that between "phases" and then
1324 // we'd just have to grow the heap up again for the next phase. So we
1325 // damp the shrinking: 0% on the first call, 10% on the second call, 40%
1326 // on the third call, and 100% by the fourth call. But if we recompute
1327 // size without shrinking, it goes back to 0%.
1328 shrink_words = shrink_words / 100 * current_shrink_factor;
1329 assert(shrink_words <= max_shrink_words,
1330 err_msg("invalid shrink size " SIZE_FORMAT " not <= " SIZE_FORMAT,
1331 shrink_words, max_shrink_words));
1332 if (current_shrink_factor == 0) {
1333 _shrink_factor = 10;
1334 } else {
1335 _shrink_factor = MIN2(current_shrink_factor * 4, (uint) 100);
1336 }
1337 if (PrintGCDetails && Verbose) {
1338 gclog_or_tty->print_cr(" "
1339 " shrinking:"
1340 " initSize: %.1fK"
1341 " maximum_desired_capacity: %.1fK",
1342 MetaspaceSize / (double) K,
1343 maximum_desired_capacity / (double) K);
1344 gclog_or_tty->print_cr(" "
1345 " shrink_words: %.1fK"
1346 " current_shrink_factor: %d"
1347 " new shrink factor: %d"
1348 " MinMetaspaceExpansion: %.1fK",
1349 shrink_words / (double) K,
1350 current_shrink_factor,
1351 _shrink_factor,
1352 MinMetaspaceExpansion / (double) K);
1353 }
1354 }
1355 }
1358 // Don't shrink unless it's significant
1359 if (shrink_words >= MinMetaspaceExpansion) {
1360 VirtualSpaceNode* csp = vsl->current_virtual_space();
1361 size_t available_to_shrink = csp->capacity_words_in_vs() -
1362 csp->used_words_in_vs();
1363 shrink_words = MIN2(shrink_words, available_to_shrink);
1364 csp->shrink_by(shrink_words);
1365 MetaspaceGC::dec_capacity_until_GC(shrink_words);
1366 if (PrintGCDetails && Verbose) {
1367 size_t new_capacity_until_GC = MetaspaceGC::capacity_until_GC_in_bytes();
1368 gclog_or_tty->print_cr(" metaspace HWM: %.1fK", new_capacity_until_GC / (double) K);
1369 }
1370 }
1371 assert(vsl->used_bytes_sum() == used_after_gc &&
1372 used_after_gc <= vsl->capacity_bytes_sum(),
1373 "sanity check");
1375 }
1377 // Metadebug methods
1379 void Metadebug::deallocate_chunk_a_lot(SpaceManager* sm,
1380 size_t chunk_word_size){
1381 #ifdef ASSERT
1382 VirtualSpaceList* vsl = sm->vs_list();
1383 if (MetaDataDeallocateALot &&
1384 Metadebug::deallocate_chunk_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
1385 Metadebug::reset_deallocate_chunk_a_lot_count();
1386 for (uint i = 0; i < metadata_deallocate_a_lock_chunk; i++) {
1387 Metachunk* dummy_chunk = vsl->current_virtual_space()->take_from_committed(chunk_word_size);
1388 if (dummy_chunk == NULL) {
1389 break;
1390 }
1391 vsl->chunk_manager()->chunk_freelist_deallocate(dummy_chunk);
1393 if (TraceMetadataChunkAllocation && Verbose) {
1394 gclog_or_tty->print("Metadebug::deallocate_chunk_a_lot: %d) ",
1395 sm->sum_count_in_chunks_in_use());
1396 dummy_chunk->print_on(gclog_or_tty);
1397 gclog_or_tty->print_cr(" Free chunks total %d count %d",
1398 vsl->chunk_manager()->free_chunks_total(),
1399 vsl->chunk_manager()->free_chunks_count());
1400 }
1401 }
1402 } else {
1403 Metadebug::inc_deallocate_chunk_a_lot_count();
1404 }
1405 #endif
1406 }
1408 void Metadebug::deallocate_block_a_lot(SpaceManager* sm,
1409 size_t raw_word_size){
1410 #ifdef ASSERT
1411 if (MetaDataDeallocateALot &&
1412 Metadebug::deallocate_block_a_lot_count() % MetaDataDeallocateALotInterval == 0 ) {
1413 Metadebug::set_deallocate_block_a_lot_count(0);
1414 for (uint i = 0; i < metadata_deallocate_a_lot_block; i++) {
1415 MetaWord* dummy_block = sm->allocate_work(raw_word_size);
1416 if (dummy_block == 0) {
1417 break;
1418 }
1419 sm->deallocate(dummy_block, raw_word_size);
1420 }
1421 } else {
1422 Metadebug::inc_deallocate_block_a_lot_count();
1423 }
1424 #endif
1425 }
1427 void Metadebug::init_allocation_fail_alot_count() {
1428 if (MetadataAllocationFailALot) {
1429 _allocation_fail_alot_count =
1430 1+(long)((double)MetadataAllocationFailALotInterval*os::random()/(max_jint+1.0));
1431 }
1432 }
1434 #ifdef ASSERT
1435 bool Metadebug::test_metadata_failure() {
1436 if (MetadataAllocationFailALot &&
1437 Threads::is_vm_complete()) {
1438 if (_allocation_fail_alot_count > 0) {
1439 _allocation_fail_alot_count--;
1440 } else {
1441 if (TraceMetadataChunkAllocation && Verbose) {
1442 gclog_or_tty->print_cr("Metadata allocation failing for "
1443 "MetadataAllocationFailALot");
1444 }
1445 init_allocation_fail_alot_count();
1446 return true;
1447 }
1448 }
1449 return false;
1450 }
1451 #endif
1453 // ChunkList methods
1455 size_t ChunkList::sum_list_size() {
1456 size_t result = 0;
1457 Metachunk* cur = head();
1458 while (cur != NULL) {
1459 result += cur->word_size();
1460 cur = cur->next();
1461 }
1462 return result;
1463 }
1465 size_t ChunkList::sum_list_count() {
1466 size_t result = 0;
1467 Metachunk* cur = head();
1468 while (cur != NULL) {
1469 result++;
1470 cur = cur->next();
1471 }
1472 return result;
1473 }
1475 size_t ChunkList::sum_list_capacity() {
1476 size_t result = 0;
1477 Metachunk* cur = head();
1478 while (cur != NULL) {
1479 result += cur->capacity_word_size();
1480 cur = cur->next();
1481 }
1482 return result;
1483 }
1485 void ChunkList::add_at_head(Metachunk* head, Metachunk* tail) {
1486 assert_lock_strong(SpaceManager::expand_lock());
1487 assert(tail->next() == NULL, "Not the tail");
1489 if (TraceMetadataChunkAllocation && Verbose) {
1490 tty->print("ChunkList::add_at_head: ");
1491 Metachunk* cur = head;
1492 while (cur != NULL) {
1493 tty->print(PTR_FORMAT " (" SIZE_FORMAT ") ", cur, cur->word_size());
1494 cur = cur->next();
1495 }
1496 tty->print_cr("");
1497 }
1499 if (tail != NULL) {
1500 tail->set_next(_head);
1501 }
1502 set_head(head);
1503 }
1505 void ChunkList::add_at_head(Metachunk* list) {
1506 if (list == NULL) {
1507 // Nothing to add
1508 return;
1509 }
1510 assert_lock_strong(SpaceManager::expand_lock());
1511 Metachunk* head = list;
1512 Metachunk* tail = list;
1513 Metachunk* cur = head->next();
1514 // Search for the tail since it is not passed.
1515 while (cur != NULL) {
1516 tail = cur;
1517 cur = cur->next();
1518 }
1519 add_at_head(head, tail);
1520 }
1522 // ChunkManager methods
1524 // Verification of _free_chunks_total and _free_chunks_count does not
1525 // work with the CMS collector because its use of additional locks
1526 // complicate the mutex deadlock detection but it can still be useful
1527 // for detecting errors in the chunk accounting with other collectors.
1529 size_t ChunkManager::free_chunks_total() {
1530 #ifdef ASSERT
1531 if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1532 MutexLockerEx cl(SpaceManager::expand_lock(),
1533 Mutex::_no_safepoint_check_flag);
1534 slow_locked_verify_free_chunks_total();
1535 }
1536 #endif
1537 return _free_chunks_total;
1538 }
1540 size_t ChunkManager::free_chunks_total_in_bytes() {
1541 return free_chunks_total() * BytesPerWord;
1542 }
1544 size_t ChunkManager::free_chunks_count() {
1545 #ifdef ASSERT
1546 if (!UseConcMarkSweepGC && !SpaceManager::expand_lock()->is_locked()) {
1547 MutexLockerEx cl(SpaceManager::expand_lock(),
1548 Mutex::_no_safepoint_check_flag);
1549 // This lock is only needed in debug because the verification
1550 // of the _free_chunks_totals walks the list of free chunks
1551 slow_locked_verify_free_chunks_count();
1552 }
1553 #endif
1554 return _free_chunks_count;
1555 }
1557 void ChunkManager::locked_verify_free_chunks_total() {
1558 assert_lock_strong(SpaceManager::expand_lock());
1559 assert(sum_free_chunks() == _free_chunks_total,
1560 err_msg("_free_chunks_total " SIZE_FORMAT " is not the"
1561 " same as sum " SIZE_FORMAT, _free_chunks_total,
1562 sum_free_chunks()));
1563 }
1565 void ChunkManager::verify_free_chunks_total() {
1566 MutexLockerEx cl(SpaceManager::expand_lock(),
1567 Mutex::_no_safepoint_check_flag);
1568 locked_verify_free_chunks_total();
1569 }
1571 void ChunkManager::locked_verify_free_chunks_count() {
1572 assert_lock_strong(SpaceManager::expand_lock());
1573 assert(sum_free_chunks_count() == _free_chunks_count,
1574 err_msg("_free_chunks_count " SIZE_FORMAT " is not the"
1575 " same as sum " SIZE_FORMAT, _free_chunks_count,
1576 sum_free_chunks_count()));
1577 }
1579 void ChunkManager::verify_free_chunks_count() {
1580 #ifdef ASSERT
1581 MutexLockerEx cl(SpaceManager::expand_lock(),
1582 Mutex::_no_safepoint_check_flag);
1583 locked_verify_free_chunks_count();
1584 #endif
1585 }
1587 void ChunkManager::verify() {
1588 MutexLockerEx cl(SpaceManager::expand_lock(),
1589 Mutex::_no_safepoint_check_flag);
1590 locked_verify();
1591 }
1593 void ChunkManager::locked_verify() {
1594 locked_verify_free_chunks_count();
1595 locked_verify_free_chunks_total();
1596 }
1598 void ChunkManager::locked_print_free_chunks(outputStream* st) {
1599 assert_lock_strong(SpaceManager::expand_lock());
1600 st->print_cr("Free chunk total 0x%x count 0x%x",
1601 _free_chunks_total, _free_chunks_count);
1602 }
1604 void ChunkManager::locked_print_sum_free_chunks(outputStream* st) {
1605 assert_lock_strong(SpaceManager::expand_lock());
1606 st->print_cr("Sum free chunk total 0x%x count 0x%x",
1607 sum_free_chunks(), sum_free_chunks_count());
1608 }
1609 ChunkList* ChunkManager::free_chunks(ChunkIndex index) {
1610 return &_free_chunks[index];
1611 }
1613 // These methods that sum the free chunk lists are used in printing
1614 // methods that are used in product builds.
1615 size_t ChunkManager::sum_free_chunks() {
1616 assert_lock_strong(SpaceManager::expand_lock());
1617 size_t result = 0;
1618 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1619 ChunkList* list = free_chunks(i);
1621 if (list == NULL) {
1622 continue;
1623 }
1625 result = result + list->sum_list_capacity();
1626 }
1627 result = result + humongous_dictionary()->total_size();
1628 return result;
1629 }
1631 size_t ChunkManager::sum_free_chunks_count() {
1632 assert_lock_strong(SpaceManager::expand_lock());
1633 size_t count = 0;
1634 for (ChunkIndex i = SmallIndex; i < NumberOfFreeLists; i = next_chunk_index(i)) {
1635 ChunkList* list = free_chunks(i);
1636 if (list == NULL) {
1637 continue;
1638 }
1639 count = count + list->sum_list_count();
1640 }
1641 count = count + humongous_dictionary()->total_free_blocks();
1642 return count;
1643 }
1645 ChunkList* ChunkManager::find_free_chunks_list(size_t word_size) {
1646 switch (word_size) {
1647 case SpaceManager::SmallChunk :
1648 return &_free_chunks[0];
1649 case SpaceManager::MediumChunk :
1650 return &_free_chunks[1];
1651 default:
1652 assert(word_size > SpaceManager::MediumChunk, "List inconsistency");
1653 return &_free_chunks[2];
1654 }
1655 }
1657 void ChunkManager::free_chunks_put(Metachunk* chunk) {
1658 assert_lock_strong(SpaceManager::expand_lock());
1659 ChunkList* free_list = find_free_chunks_list(chunk->word_size());
1660 chunk->set_next(free_list->head());
1661 free_list->set_head(chunk);
1662 // chunk is being returned to the chunk free list
1663 inc_free_chunks_total(chunk->capacity_word_size());
1664 slow_locked_verify();
1665 }
1667 void ChunkManager::chunk_freelist_deallocate(Metachunk* chunk) {
1668 // The deallocation of a chunk originates in the freelist
1669 // manangement code for a Metaspace and does not hold the
1670 // lock.
1671 assert(chunk != NULL, "Deallocating NULL");
1672 assert_lock_strong(SpaceManager::expand_lock());
1673 slow_locked_verify();
1674 if (TraceMetadataChunkAllocation) {
1675 tty->print_cr("ChunkManager::chunk_freelist_deallocate: chunk "
1676 PTR_FORMAT " size " SIZE_FORMAT,
1677 chunk, chunk->word_size());
1678 }
1679 free_chunks_put(chunk);
1680 }
1682 Metachunk* ChunkManager::free_chunks_get(size_t word_size) {
1683 assert_lock_strong(SpaceManager::expand_lock());
1685 slow_locked_verify();
1687 Metachunk* chunk = NULL;
1688 if (!SpaceManager::is_humongous(word_size)) {
1689 ChunkList* free_list = find_free_chunks_list(word_size);
1690 assert(free_list != NULL, "Sanity check");
1692 chunk = free_list->head();
1693 debug_only(Metachunk* debug_head = chunk;)
1695 if (chunk == NULL) {
1696 return NULL;
1697 }
1699 // Remove the chunk as the head of the list.
1700 free_list->set_head(chunk->next());
1701 chunk->set_next(NULL);
1702 // Chunk has been removed from the chunks free list.
1703 dec_free_chunks_total(chunk->capacity_word_size());
1705 if (TraceMetadataChunkAllocation && Verbose) {
1706 tty->print_cr("ChunkManager::free_chunks_get: free_list "
1707 PTR_FORMAT " head " PTR_FORMAT " size " SIZE_FORMAT,
1708 free_list, chunk, chunk->word_size());
1709 }
1710 } else {
1711 chunk = humongous_dictionary()->get_chunk(
1712 word_size,
1713 FreeBlockDictionary<Metachunk>::atLeast);
1715 if (chunk != NULL) {
1716 if (TraceMetadataHumongousAllocation) {
1717 size_t waste = chunk->word_size() - word_size;
1718 tty->print_cr("Free list allocate humongous chunk size " SIZE_FORMAT
1719 " for requested size " SIZE_FORMAT
1720 " waste " SIZE_FORMAT,
1721 chunk->word_size(), word_size, waste);
1722 }
1723 // Chunk is being removed from the chunks free list.
1724 dec_free_chunks_total(chunk->capacity_word_size());
1725 #ifdef ASSERT
1726 chunk->set_is_free(false);
1727 #endif
1728 }
1729 }
1730 slow_locked_verify();
1731 return chunk;
1732 }
1734 Metachunk* ChunkManager::chunk_freelist_allocate(size_t word_size) {
1735 assert_lock_strong(SpaceManager::expand_lock());
1736 slow_locked_verify();
1738 // Take from the beginning of the list
1739 Metachunk* chunk = free_chunks_get(word_size);
1740 if (chunk == NULL) {
1741 return NULL;
1742 }
1744 assert(word_size <= chunk->word_size() ||
1745 SpaceManager::is_humongous(chunk->word_size()),
1746 "Non-humongous variable sized chunk");
1747 if (TraceMetadataChunkAllocation) {
1748 tty->print("ChunkManager::chunk_freelist_allocate: chunk "
1749 PTR_FORMAT " size " SIZE_FORMAT " ",
1750 chunk, chunk->word_size());
1751 locked_print_free_chunks(tty);
1752 }
1754 return chunk;
1755 }
1757 void ChunkManager::print_on(outputStream* out) {
1758 if (PrintFLSStatistics != 0) {
1759 humongous_dictionary()->report_statistics();
1760 }
1761 }
1763 // SpaceManager methods
1765 size_t SpaceManager::sum_free_in_chunks_in_use() const {
1766 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1767 size_t free = 0;
1768 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1769 Metachunk* chunk = chunks_in_use(i);
1770 while (chunk != NULL) {
1771 free += chunk->free_word_size();
1772 chunk = chunk->next();
1773 }
1774 }
1775 return free;
1776 }
1778 size_t SpaceManager::sum_waste_in_chunks_in_use() const {
1779 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1780 size_t result = 0;
1781 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1784 result += sum_waste_in_chunks_in_use(i);
1785 }
1787 return result;
1788 }
1790 size_t SpaceManager::sum_waste_in_chunks_in_use(ChunkIndex index) const {
1791 size_t result = 0;
1792 size_t count = 0;
1793 Metachunk* chunk = chunks_in_use(index);
1794 // Count the free space in all the chunk but not the
1795 // current chunk from which allocations are still being done.
1796 if (chunk != NULL) {
1797 Metachunk* prev = chunk;
1798 while (chunk != NULL && chunk != current_chunk()) {
1799 result += chunk->free_word_size();
1800 prev = chunk;
1801 chunk = chunk->next();
1802 count++;
1803 }
1804 }
1805 return result;
1806 }
1808 size_t SpaceManager::sum_capacity_in_chunks_in_use() const {
1809 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1810 size_t sum = 0;
1811 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1812 Metachunk* chunk = chunks_in_use(i);
1813 while (chunk != NULL) {
1814 // Just changed this sum += chunk->capacity_word_size();
1815 // sum += chunk->word_size() - Metachunk::overhead();
1816 sum += chunk->capacity_word_size();
1817 chunk = chunk->next();
1818 }
1819 }
1820 return sum;
1821 }
1823 size_t SpaceManager::sum_count_in_chunks_in_use() {
1824 size_t count = 0;
1825 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1826 count = count + sum_count_in_chunks_in_use(i);
1827 }
1829 return count;
1830 }
1832 size_t SpaceManager::sum_count_in_chunks_in_use(ChunkIndex i) {
1833 size_t count = 0;
1834 Metachunk* chunk = chunks_in_use(i);
1835 while (chunk != NULL) {
1836 count++;
1837 chunk = chunk->next();
1838 }
1839 return count;
1840 }
1843 size_t SpaceManager::sum_used_in_chunks_in_use() const {
1844 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
1845 size_t used = 0;
1846 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1847 Metachunk* chunk = chunks_in_use(i);
1848 while (chunk != NULL) {
1849 used += chunk->used_word_size();
1850 chunk = chunk->next();
1851 }
1852 }
1853 return used;
1854 }
1856 void SpaceManager::locked_print_chunks_in_use_on(outputStream* st) const {
1858 Metachunk* small_chunk = chunks_in_use(SmallIndex);
1859 st->print_cr("SpaceManager: small chunk " PTR_FORMAT
1860 " free " SIZE_FORMAT,
1861 small_chunk,
1862 small_chunk->free_word_size());
1864 Metachunk* medium_chunk = chunks_in_use(MediumIndex);
1865 st->print("medium chunk " PTR_FORMAT, medium_chunk);
1866 Metachunk* tail = current_chunk();
1867 st->print_cr(" current chunk " PTR_FORMAT, tail);
1869 Metachunk* head = chunks_in_use(HumongousIndex);
1870 st->print_cr("humongous chunk " PTR_FORMAT, head);
1872 vs_list()->chunk_manager()->locked_print_free_chunks(st);
1873 vs_list()->chunk_manager()->locked_print_sum_free_chunks(st);
1874 }
1876 size_t SpaceManager::calc_chunk_size(size_t word_size) {
1878 // Decide between a small chunk and a medium chunk. Up to
1879 // _small_chunk_limit small chunks can be allocated but
1880 // once a medium chunk has been allocated, no more small
1881 // chunks will be allocated.
1882 size_t chunk_word_size;
1883 if (chunks_in_use(MediumIndex) == NULL &&
1884 (!has_small_chunk_limit() ||
1885 sum_count_in_chunks_in_use(SmallIndex) < _small_chunk_limit)) {
1886 chunk_word_size = (size_t) SpaceManager::SmallChunk;
1887 if (word_size + Metachunk::overhead() > SpaceManager::SmallChunk) {
1888 chunk_word_size = MediumChunk;
1889 }
1890 } else {
1891 chunk_word_size = MediumChunk;
1892 }
1894 // Might still need a humongous chunk
1895 chunk_word_size =
1896 MAX2((size_t) chunk_word_size, word_size + Metachunk::overhead());
1898 if (TraceMetadataHumongousAllocation &&
1899 SpaceManager::is_humongous(word_size)) {
1900 gclog_or_tty->print_cr("Metadata humongous allocation:");
1901 gclog_or_tty->print_cr(" word_size " PTR_FORMAT, word_size);
1902 gclog_or_tty->print_cr(" chunk_word_size " PTR_FORMAT,
1903 chunk_word_size);
1904 gclog_or_tty->print_cr(" chunk overhead " PTR_FORMAT,
1905 Metachunk::overhead());
1906 }
1907 return chunk_word_size;
1908 }
1910 MetaWord* SpaceManager::grow_and_allocate(size_t word_size) {
1911 assert(vs_list()->current_virtual_space() != NULL,
1912 "Should have been set");
1913 assert(current_chunk() == NULL ||
1914 current_chunk()->allocate(word_size) == NULL,
1915 "Don't need to expand");
1916 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
1918 if (TraceMetadataChunkAllocation && Verbose) {
1919 gclog_or_tty->print_cr("SpaceManager::grow_and_allocate for " SIZE_FORMAT
1920 " words " SIZE_FORMAT " space left",
1921 word_size, current_chunk() != NULL ?
1922 current_chunk()->free_word_size() : 0);
1923 }
1925 // Get another chunk out of the virtual space
1926 size_t grow_chunks_by_words = calc_chunk_size(word_size);
1927 Metachunk* next = vs_list()->get_new_chunk(word_size, grow_chunks_by_words);
1929 // If a chunk was available, add it to the in-use chunk list
1930 // and do an allocation from it.
1931 if (next != NULL) {
1932 Metadebug::deallocate_chunk_a_lot(this, grow_chunks_by_words);
1933 // Add to this manager's list of chunks in use.
1934 add_chunk(next, false);
1935 return next->allocate(word_size);
1936 }
1937 return NULL;
1938 }
1940 void SpaceManager::print_on(outputStream* st) const {
1942 for (ChunkIndex i = SmallIndex;
1943 i < NumberOfInUseLists ;
1944 i = next_chunk_index(i) ) {
1945 st->print_cr(" chunks_in_use " PTR_FORMAT " chunk size " PTR_FORMAT,
1946 chunks_in_use(i),
1947 chunks_in_use(i) == NULL ? 0 : chunks_in_use(i)->word_size());
1948 }
1949 st->print_cr(" waste: Small " SIZE_FORMAT " Medium " SIZE_FORMAT
1950 " Humongous " SIZE_FORMAT,
1951 sum_waste_in_chunks_in_use(SmallIndex),
1952 sum_waste_in_chunks_in_use(MediumIndex),
1953 sum_waste_in_chunks_in_use(HumongousIndex));
1954 // block free lists
1955 if (block_freelists() != NULL) {
1956 st->print_cr("total in block free lists " SIZE_FORMAT,
1957 block_freelists()->total_size());
1958 }
1959 }
1961 SpaceManager::SpaceManager(Mutex* lock, VirtualSpaceList* vs_list) :
1962 _vs_list(vs_list),
1963 _allocation_total(0),
1964 _lock(lock) {
1965 Metadebug::init_allocation_fail_alot_count();
1966 for (ChunkIndex i = SmallIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
1967 _chunks_in_use[i] = NULL;
1968 }
1969 _current_chunk = NULL;
1970 if (TraceMetadataChunkAllocation && Verbose) {
1971 gclog_or_tty->print_cr("SpaceManager(): " PTR_FORMAT, this);
1972 }
1973 }
1975 SpaceManager::~SpaceManager() {
1976 MutexLockerEx fcl(SpaceManager::expand_lock(),
1977 Mutex::_no_safepoint_check_flag);
1979 ChunkManager* chunk_manager = vs_list()->chunk_manager();
1981 chunk_manager->slow_locked_verify();
1983 if (TraceMetadataChunkAllocation && Verbose) {
1984 gclog_or_tty->print_cr("~SpaceManager(): " PTR_FORMAT, this);
1985 locked_print_chunks_in_use_on(gclog_or_tty);
1986 }
1988 // Have to update before the chunks_in_use lists are emptied
1989 // below.
1990 chunk_manager->inc_free_chunks_total(sum_capacity_in_chunks_in_use(),
1991 sum_count_in_chunks_in_use());
1993 #ifdef ASSERT
1994 // Mangle freed memory.
1995 mangle_freed_chunks();
1996 #endif // ASSERT
1998 // Add all the chunks in use by this space manager
1999 // to the global list of free chunks.
2001 // Small chunks. There is one _current_chunk for each
2002 // Metaspace. It could point to a small or medium chunk.
2003 // Rather than determine which it is, follow the list of
2004 // small chunks to add them to the free list
2005 Metachunk* small_chunk = chunks_in_use(SmallIndex);
2006 chunk_manager->free_small_chunks()->add_at_head(small_chunk);
2007 set_chunks_in_use(SmallIndex, NULL);
2009 // After the small chunk are the medium chunks
2010 Metachunk* medium_chunk = chunks_in_use(MediumIndex);
2011 assert(medium_chunk == NULL ||
2012 medium_chunk->word_size() == MediumChunk,
2013 "Chunk is on the wrong list");
2015 if (medium_chunk != NULL) {
2016 Metachunk* head = medium_chunk;
2017 // If there is a medium chunk then the _current_chunk can only
2018 // point to the last medium chunk.
2019 Metachunk* tail = current_chunk();
2020 chunk_manager->free_medium_chunks()->add_at_head(head, tail);
2021 set_chunks_in_use(MediumIndex, NULL);
2022 }
2024 // Humongous chunks
2025 // Humongous chunks are never the current chunk.
2026 Metachunk* humongous_chunks = chunks_in_use(HumongousIndex);
2028 while (humongous_chunks != NULL) {
2029 #ifdef ASSERT
2030 humongous_chunks->set_is_free(true);
2031 #endif
2032 Metachunk* next_humongous_chunks = humongous_chunks->next();
2033 chunk_manager->humongous_dictionary()->return_chunk(humongous_chunks);
2034 humongous_chunks = next_humongous_chunks;
2035 }
2036 set_chunks_in_use(HumongousIndex, NULL);
2037 chunk_manager->slow_locked_verify();
2038 }
2040 void SpaceManager::deallocate(MetaWord* p, size_t word_size) {
2041 assert_lock_strong(_lock);
2042 size_t min_size = TreeChunk<Metablock, FreeList>::min_size();
2043 assert(word_size >= min_size,
2044 err_msg("Should not deallocate dark matter " SIZE_FORMAT, word_size));
2045 block_freelists()->return_block(p, word_size);
2046 }
2048 // Adds a chunk to the list of chunks in use.
2049 void SpaceManager::add_chunk(Metachunk* new_chunk, bool make_current) {
2051 assert(new_chunk != NULL, "Should not be NULL");
2052 assert(new_chunk->next() == NULL, "Should not be on a list");
2054 new_chunk->reset_empty();
2056 // Find the correct list and and set the current
2057 // chunk for that list.
2058 switch (new_chunk->word_size()) {
2059 case SpaceManager::SmallChunk :
2060 if (chunks_in_use(SmallIndex) == NULL) {
2061 // First chunk to add to the list
2062 set_chunks_in_use(SmallIndex, new_chunk);
2063 } else {
2064 assert(current_chunk()->word_size() == SpaceManager::SmallChunk,
2065 err_msg( "Incorrect mix of sizes in chunk list "
2066 SIZE_FORMAT " new chunk " SIZE_FORMAT,
2067 current_chunk()->word_size(), new_chunk->word_size()));
2068 current_chunk()->set_next(new_chunk);
2069 }
2070 // Make current chunk
2071 set_current_chunk(new_chunk);
2072 break;
2073 case SpaceManager::MediumChunk :
2074 if (chunks_in_use(MediumIndex) == NULL) {
2075 // About to add the first medium chunk so teminate the
2076 // small chunk list. In general once medium chunks are
2077 // being added, we're past the need for small chunks.
2078 if (current_chunk() != NULL) {
2079 // Only a small chunk or the initial chunk could be
2080 // the current chunk if this is the first medium chunk.
2081 assert(current_chunk()->word_size() == SpaceManager::SmallChunk ||
2082 chunks_in_use(SmallIndex) == NULL,
2083 err_msg("Should be a small chunk or initial chunk, current chunk "
2084 SIZE_FORMAT " new chunk " SIZE_FORMAT,
2085 current_chunk()->word_size(), new_chunk->word_size()));
2086 current_chunk()->set_next(NULL);
2087 }
2088 // First chunk to add to the list
2089 set_chunks_in_use(MediumIndex, new_chunk);
2091 } else {
2092 // As a minimum the first medium chunk added would
2093 // have become the _current_chunk
2094 // so the _current_chunk has to be non-NULL here
2095 // (although not necessarily still the first medium chunk).
2096 assert(current_chunk()->word_size() == SpaceManager::MediumChunk,
2097 "A medium chunk should the current chunk");
2098 current_chunk()->set_next(new_chunk);
2099 }
2100 // Make current chunk
2101 set_current_chunk(new_chunk);
2102 break;
2103 default: {
2104 // For null class loader data and DumpSharedSpaces, the first chunk isn't
2105 // small, so small will be null. Link this first chunk as the current
2106 // chunk.
2107 if (make_current) {
2108 // Set as the current chunk but otherwise treat as a humongous chunk.
2109 set_current_chunk(new_chunk);
2110 }
2111 // Link at head. The _current_chunk only points to a humongous chunk for
2112 // the null class loader metaspace (class and data virtual space managers)
2113 // any humongous chunks so will not point to the tail
2114 // of the humongous chunks list.
2115 new_chunk->set_next(chunks_in_use(HumongousIndex));
2116 set_chunks_in_use(HumongousIndex, new_chunk);
2118 assert(new_chunk->word_size() > MediumChunk, "List inconsistency");
2119 }
2120 }
2122 assert(new_chunk->is_empty(), "Not ready for reuse");
2123 if (TraceMetadataChunkAllocation && Verbose) {
2124 gclog_or_tty->print("SpaceManager::add_chunk: %d) ",
2125 sum_count_in_chunks_in_use());
2126 new_chunk->print_on(gclog_or_tty);
2127 vs_list()->chunk_manager()->locked_print_free_chunks(tty);
2128 }
2129 }
2131 MetaWord* SpaceManager::allocate(size_t word_size) {
2132 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2134 // If only the dictionary is going to be used (i.e., no
2135 // indexed free list), then there is a minimum size requirement.
2136 // MinChunkSize is a placeholder for the real minimum size JJJ
2137 size_t byte_size = word_size * BytesPerWord;
2139 size_t byte_size_with_overhead = byte_size + Metablock::overhead();
2141 size_t raw_bytes_size = MAX2(byte_size_with_overhead,
2142 Metablock::min_block_byte_size());
2143 raw_bytes_size = ARENA_ALIGN(raw_bytes_size);
2144 size_t raw_word_size = raw_bytes_size / BytesPerWord;
2145 assert(raw_word_size * BytesPerWord == raw_bytes_size, "Size problem");
2147 BlockFreelist* fl = block_freelists();
2148 MetaWord* p = NULL;
2149 // Allocation from the dictionary is expensive in the sense that
2150 // the dictionary has to be searched for a size. Don't allocate
2151 // from the dictionary until it starts to get fat. Is this
2152 // a reasonable policy? Maybe an skinny dictionary is fast enough
2153 // for allocations. Do some profiling. JJJ
2154 if (fl->total_size() > allocation_from_dictionary_limit) {
2155 p = fl->get_block(raw_word_size);
2156 }
2157 if (p == NULL) {
2158 p = allocate_work(raw_word_size);
2159 }
2160 Metadebug::deallocate_block_a_lot(this, raw_word_size);
2162 return p;
2163 }
2165 // Returns the address of spaced allocated for "word_size".
2166 // This methods does not know about blocks (Metablocks)
2167 MetaWord* SpaceManager::allocate_work(size_t word_size) {
2168 assert_lock_strong(_lock);
2169 #ifdef ASSERT
2170 if (Metadebug::test_metadata_failure()) {
2171 return NULL;
2172 }
2173 #endif
2174 // Is there space in the current chunk?
2175 MetaWord* result = NULL;
2177 // For DumpSharedSpaces, only allocate out of the current chunk which is
2178 // never null because we gave it the size we wanted. Caller reports out
2179 // of memory if this returns null.
2180 if (DumpSharedSpaces) {
2181 assert(current_chunk() != NULL, "should never happen");
2182 inc_allocation_total(word_size);
2183 return current_chunk()->allocate(word_size); // caller handles null result
2184 }
2185 if (current_chunk() != NULL) {
2186 result = current_chunk()->allocate(word_size);
2187 }
2189 if (result == NULL) {
2190 result = grow_and_allocate(word_size);
2191 }
2192 if (result > 0) {
2193 inc_allocation_total(word_size);
2194 assert(result != (MetaWord*) chunks_in_use(MediumIndex),
2195 "Head of the list is being allocated");
2196 }
2198 return result;
2199 }
2201 void SpaceManager::verify() {
2202 // If there are blocks in the dictionary, then
2203 // verfication of chunks does not work since
2204 // being in the dictionary alters a chunk.
2205 if (block_freelists()->total_size() == 0) {
2206 // Skip the small chunks because their next link points to
2207 // medium chunks. This is because the small chunk is the
2208 // current chunk (for allocations) until it is full and the
2209 // the addition of the next chunk does not NULL the next
2210 // like of the small chunk.
2211 for (ChunkIndex i = MediumIndex; i < NumberOfInUseLists; i = next_chunk_index(i)) {
2212 Metachunk* curr = chunks_in_use(i);
2213 while (curr != NULL) {
2214 curr->verify();
2215 curr = curr->next();
2216 }
2217 }
2218 }
2219 }
2221 #ifdef ASSERT
2222 void SpaceManager::verify_allocation_total() {
2223 #if 0
2224 // Verification is only guaranteed at a safepoint.
2225 if (SafepointSynchronize::is_at_safepoint()) {
2226 gclog_or_tty->print_cr("Chunk " PTR_FORMAT " allocation_total " SIZE_FORMAT
2227 " sum_used_in_chunks_in_use " SIZE_FORMAT,
2228 this,
2229 allocation_total(),
2230 sum_used_in_chunks_in_use());
2231 }
2232 MutexLockerEx cl(lock(), Mutex::_no_safepoint_check_flag);
2233 assert(allocation_total() == sum_used_in_chunks_in_use(),
2234 err_msg("allocation total is not consistent %d vs %d",
2235 allocation_total(), sum_used_in_chunks_in_use()));
2236 #endif
2237 }
2239 #endif
2241 void SpaceManager::dump(outputStream* const out) const {
2242 size_t curr_total = 0;
2243 size_t waste = 0;
2244 uint i = 0;
2245 size_t used = 0;
2246 size_t capacity = 0;
2248 // Add up statistics for all chunks in this SpaceManager.
2249 for (ChunkIndex index = SmallIndex;
2250 index < NumberOfInUseLists;
2251 index = next_chunk_index(index)) {
2252 for (Metachunk* curr = chunks_in_use(index);
2253 curr != NULL;
2254 curr = curr->next()) {
2255 out->print("%d) ", i++);
2256 curr->print_on(out);
2257 if (TraceMetadataChunkAllocation && Verbose) {
2258 block_freelists()->print_on(out);
2259 }
2260 curr_total += curr->word_size();
2261 used += curr->used_word_size();
2262 capacity += curr->capacity_word_size();
2263 waste += curr->free_word_size() + curr->overhead();;
2264 }
2265 }
2267 size_t free = current_chunk()->free_word_size();
2268 // Free space isn't wasted.
2269 waste -= free;
2271 out->print_cr("total of all chunks " SIZE_FORMAT " used " SIZE_FORMAT
2272 " free " SIZE_FORMAT " capacity " SIZE_FORMAT
2273 " waste " SIZE_FORMAT, curr_total, used, free, capacity, waste);
2274 }
2276 #ifdef ASSERT
2277 void SpaceManager::mangle_freed_chunks() {
2278 for (ChunkIndex index = SmallIndex;
2279 index < NumberOfInUseLists;
2280 index = next_chunk_index(index)) {
2281 for (Metachunk* curr = chunks_in_use(index);
2282 curr != NULL;
2283 curr = curr->next()) {
2284 // Try to detect incorrectly terminated small chunk
2285 // list.
2286 assert(index == MediumIndex || curr != chunks_in_use(MediumIndex),
2287 err_msg("Mangling medium chunks in small chunks? "
2288 "curr " PTR_FORMAT " medium list " PTR_FORMAT,
2289 curr, chunks_in_use(MediumIndex)));
2290 curr->mangle();
2291 }
2292 }
2293 }
2294 #endif // ASSERT
2297 // MetaspaceAux
2299 size_t MetaspaceAux::used_in_bytes(Metaspace::MetadataType mdtype) {
2300 size_t used = 0;
2301 ClassLoaderDataGraphMetaspaceIterator iter;
2302 while (iter.repeat()) {
2303 Metaspace* msp = iter.get_next();
2304 // Sum allocation_total for each metaspace
2305 if (msp != NULL) {
2306 used += msp->used_words(mdtype);
2307 }
2308 }
2309 return used * BytesPerWord;
2310 }
2312 size_t MetaspaceAux::free_in_bytes(Metaspace::MetadataType mdtype) {
2313 size_t free = 0;
2314 ClassLoaderDataGraphMetaspaceIterator iter;
2315 while (iter.repeat()) {
2316 Metaspace* msp = iter.get_next();
2317 if (msp != NULL) {
2318 free += msp->free_words(mdtype);
2319 }
2320 }
2321 return free * BytesPerWord;
2322 }
2324 // The total words available for metadata allocation. This
2325 // uses Metaspace capacity_words() which is the total words
2326 // in chunks allocated for a Metaspace.
2327 size_t MetaspaceAux::capacity_in_bytes(Metaspace::MetadataType mdtype) {
2328 size_t capacity = free_chunks_total(mdtype);
2329 ClassLoaderDataGraphMetaspaceIterator iter;
2330 while (iter.repeat()) {
2331 Metaspace* msp = iter.get_next();
2332 if (msp != NULL) {
2333 capacity += msp->capacity_words(mdtype);
2334 }
2335 }
2336 return capacity * BytesPerWord;
2337 }
2339 size_t MetaspaceAux::reserved_in_bytes(Metaspace::MetadataType mdtype) {
2340 size_t reserved = (mdtype == Metaspace::ClassType) ?
2341 Metaspace::class_space_list()->virtual_space_total() :
2342 Metaspace::space_list()->virtual_space_total();
2343 return reserved * BytesPerWord;
2344 }
2346 size_t MetaspaceAux::min_chunk_size() { return SpaceManager::MediumChunk; }
2348 size_t MetaspaceAux::free_chunks_total(Metaspace::MetadataType mdtype) {
2349 ChunkManager* chunk = (mdtype == Metaspace::ClassType) ?
2350 Metaspace::class_space_list()->chunk_manager() :
2351 Metaspace::space_list()->chunk_manager();
2352 chunk->slow_verify();
2353 return chunk->free_chunks_total();
2354 }
2356 size_t MetaspaceAux::free_chunks_total_in_bytes(Metaspace::MetadataType mdtype) {
2357 return free_chunks_total(mdtype) * BytesPerWord;
2358 }
2360 void MetaspaceAux::print_metaspace_change(size_t prev_metadata_used) {
2361 gclog_or_tty->print(", [Metaspace:");
2362 if (PrintGCDetails && Verbose) {
2363 gclog_or_tty->print(" " SIZE_FORMAT
2364 "->" SIZE_FORMAT
2365 "(" SIZE_FORMAT "/" SIZE_FORMAT ")",
2366 prev_metadata_used,
2367 used_in_bytes(),
2368 capacity_in_bytes(),
2369 reserved_in_bytes());
2370 } else {
2371 gclog_or_tty->print(" " SIZE_FORMAT "K"
2372 "->" SIZE_FORMAT "K"
2373 "(" SIZE_FORMAT "K/" SIZE_FORMAT "K)",
2374 prev_metadata_used / K,
2375 used_in_bytes()/ K,
2376 capacity_in_bytes()/K,
2377 reserved_in_bytes()/ K);
2378 }
2380 gclog_or_tty->print("]");
2381 }
2383 // This is printed when PrintGCDetails
2384 void MetaspaceAux::print_on(outputStream* out) {
2385 Metaspace::MetadataType ct = Metaspace::ClassType;
2386 Metaspace::MetadataType nct = Metaspace::NonClassType;
2388 out->print_cr(" Metaspace total "
2389 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2390 " reserved " SIZE_FORMAT "K",
2391 capacity_in_bytes()/K, used_in_bytes()/K, reserved_in_bytes()/K);
2392 out->print_cr(" data space "
2393 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2394 " reserved " SIZE_FORMAT "K",
2395 capacity_in_bytes(nct)/K, used_in_bytes(nct)/K, reserved_in_bytes(nct)/K);
2396 out->print_cr(" class space "
2397 SIZE_FORMAT "K, used " SIZE_FORMAT "K,"
2398 " reserved " SIZE_FORMAT "K",
2399 capacity_in_bytes(ct)/K, used_in_bytes(ct)/K, reserved_in_bytes(ct)/K);
2400 }
2402 // Print information for class space and data space separately.
2403 // This is almost the same as above.
2404 void MetaspaceAux::print_on(outputStream* out, Metaspace::MetadataType mdtype) {
2405 size_t free_chunks_capacity_bytes = free_chunks_total_in_bytes(mdtype);
2406 size_t capacity_bytes = capacity_in_bytes(mdtype);
2407 size_t used_bytes = used_in_bytes(mdtype);
2408 size_t free_bytes = free_in_bytes(mdtype);
2409 size_t used_and_free = used_bytes + free_bytes +
2410 free_chunks_capacity_bytes;
2411 out->print_cr(" Chunk accounting: used in chunks " SIZE_FORMAT
2412 "K + unused in chunks " SIZE_FORMAT "K + "
2413 " capacity in free chunks " SIZE_FORMAT "K = " SIZE_FORMAT
2414 "K capacity in allocated chunks " SIZE_FORMAT "K",
2415 used_bytes / K,
2416 free_bytes / K,
2417 free_chunks_capacity_bytes / K,
2418 used_and_free / K,
2419 capacity_bytes / K);
2420 assert(used_and_free == capacity_bytes, "Accounting is wrong");
2421 }
2423 // Print total fragmentation for class and data metaspaces separately
2424 void MetaspaceAux::print_waste(outputStream* out) {
2426 size_t small_waste = 0, medium_waste = 0, large_waste = 0;
2427 size_t cls_small_waste = 0, cls_medium_waste = 0, cls_large_waste = 0;
2429 ClassLoaderDataGraphMetaspaceIterator iter;
2430 while (iter.repeat()) {
2431 Metaspace* msp = iter.get_next();
2432 if (msp != NULL) {
2433 small_waste += msp->vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2434 medium_waste += msp->vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2435 large_waste += msp->vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
2437 cls_small_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(SmallIndex);
2438 cls_medium_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(MediumIndex);
2439 cls_large_waste += msp->class_vsm()->sum_waste_in_chunks_in_use(HumongousIndex);
2440 }
2441 }
2442 out->print_cr("Total fragmentation waste (words) doesn't count free space");
2443 out->print(" data: small " SIZE_FORMAT " medium " SIZE_FORMAT,
2444 small_waste, medium_waste);
2445 out->print_cr(" class: small " SIZE_FORMAT, cls_small_waste);
2446 }
2448 // Dump global metaspace things from the end of ClassLoaderDataGraph
2449 void MetaspaceAux::dump(outputStream* out) {
2450 out->print_cr("All Metaspace:");
2451 out->print("data space: "); print_on(out, Metaspace::NonClassType);
2452 out->print("class space: "); print_on(out, Metaspace::ClassType);
2453 print_waste(out);
2454 }
2456 void MetaspaceAux::verify_free_chunks() {
2457 Metaspace::space_list()->chunk_manager()->verify();
2458 Metaspace::class_space_list()->chunk_manager()->verify();
2459 }
2461 // Metaspace methods
2463 size_t Metaspace::_first_chunk_word_size = 0;
2465 Metaspace::Metaspace(Mutex* lock, size_t word_size) {
2466 initialize(lock, word_size);
2467 }
2469 Metaspace::Metaspace(Mutex* lock) {
2470 initialize(lock);
2471 }
2473 Metaspace::~Metaspace() {
2474 delete _vsm;
2475 delete _class_vsm;
2476 }
2478 VirtualSpaceList* Metaspace::_space_list = NULL;
2479 VirtualSpaceList* Metaspace::_class_space_list = NULL;
2481 #define VIRTUALSPACEMULTIPLIER 2
2483 void Metaspace::global_initialize() {
2484 // Initialize the alignment for shared spaces.
2485 int max_alignment = os::vm_page_size();
2486 MetaspaceShared::set_max_alignment(max_alignment);
2488 if (DumpSharedSpaces) {
2489 SharedReadOnlySize = align_size_up(SharedReadOnlySize, max_alignment);
2490 SharedReadWriteSize = align_size_up(SharedReadWriteSize, max_alignment);
2491 SharedMiscDataSize = align_size_up(SharedMiscDataSize, max_alignment);
2492 SharedMiscCodeSize = align_size_up(SharedMiscCodeSize, max_alignment);
2494 // Initialize with the sum of the shared space sizes. The read-only
2495 // and read write metaspace chunks will be allocated out of this and the
2496 // remainder is the misc code and data chunks.
2497 size_t total = align_size_up(SharedReadOnlySize + SharedReadWriteSize +
2498 SharedMiscDataSize + SharedMiscCodeSize,
2499 os::vm_allocation_granularity());
2500 size_t word_size = total/wordSize;
2501 _space_list = new VirtualSpaceList(word_size);
2502 } else {
2503 // If using shared space, open the file that contains the shared space
2504 // and map in the memory before initializing the rest of metaspace (so
2505 // the addresses don't conflict)
2506 if (UseSharedSpaces) {
2507 FileMapInfo* mapinfo = new FileMapInfo();
2508 memset(mapinfo, 0, sizeof(FileMapInfo));
2510 // Open the shared archive file, read and validate the header. If
2511 // initialization fails, shared spaces [UseSharedSpaces] are
2512 // disabled and the file is closed.
2513 // Map in spaces now also
2514 if (mapinfo->initialize() && MetaspaceShared::map_shared_spaces(mapinfo)) {
2515 FileMapInfo::set_current_info(mapinfo);
2516 } else {
2517 assert(!mapinfo->is_open() && !UseSharedSpaces,
2518 "archive file not closed or shared spaces not disabled.");
2519 }
2520 }
2522 // Initialize this before initializing the VirtualSpaceList
2523 _first_chunk_word_size = InitialBootClassLoaderMetaspaceSize / BytesPerWord;
2524 // Arbitrarily set the initial virtual space to a multiple
2525 // of the boot class loader size.
2526 size_t word_size = VIRTUALSPACEMULTIPLIER * Metaspace::first_chunk_word_size();
2527 // Initialize the list of virtual spaces.
2528 _space_list = new VirtualSpaceList(word_size);
2529 }
2530 }
2532 // For UseCompressedKlassPointers the class space is reserved as a piece of the
2533 // Java heap because the compression algorithm is the same for each. The
2534 // argument passed in is at the top of the compressed space
2535 void Metaspace::initialize_class_space(ReservedSpace rs) {
2536 // The reserved space size may be bigger because of alignment, esp with UseLargePages
2537 assert(rs.size() >= ClassMetaspaceSize, err_msg("%d != %d", rs.size(), ClassMetaspaceSize));
2538 _class_space_list = new VirtualSpaceList(rs);
2539 }
2542 void Metaspace::initialize(Mutex* lock, size_t initial_size) {
2543 // Use SmallChunk size if not specified. If specified, use this size for
2544 // the data metaspace.
2545 size_t word_size;
2546 size_t class_word_size;
2547 if (initial_size == 0) {
2548 word_size = (size_t) SpaceManager::SmallChunk;
2549 class_word_size = (size_t) SpaceManager::SmallChunk;
2550 } else {
2551 word_size = initial_size;
2552 // Make the first class chunk bigger than a medium chunk so it's not put
2553 // on the medium chunk list. The next chunk will be small and progress
2554 // from there. This size calculated by -version.
2555 class_word_size = MIN2((size_t)SpaceManager::MediumChunk*5,
2556 (ClassMetaspaceSize/BytesPerWord)*2);
2557 }
2559 assert(space_list() != NULL,
2560 "Metadata VirtualSpaceList has not been initialized");
2562 _vsm = new SpaceManager(lock, space_list());
2563 if (_vsm == NULL) {
2564 return;
2565 }
2567 assert(class_space_list() != NULL,
2568 "Class VirtualSpaceList has not been initialized");
2570 // Allocate SpaceManager for classes.
2571 _class_vsm = new SpaceManager(lock, class_space_list());
2572 if (_class_vsm == NULL) {
2573 return;
2574 }
2576 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2578 // Allocate chunk for metadata objects
2579 Metachunk* new_chunk =
2580 space_list()->current_virtual_space()->get_chunk_vs_with_expand(word_size);
2581 assert(!DumpSharedSpaces || new_chunk != NULL, "should have enough space for both chunks");
2582 if (new_chunk != NULL) {
2583 // Add to this manager's list of chunks in use and current_chunk().
2584 vsm()->add_chunk(new_chunk, true);
2585 }
2587 // Allocate chunk for class metadata objects
2588 Metachunk* class_chunk =
2589 class_space_list()->current_virtual_space()->get_chunk_vs_with_expand(class_word_size);
2590 if (class_chunk != NULL) {
2591 class_vsm()->add_chunk(class_chunk, true);
2592 }
2593 }
2595 MetaWord* Metaspace::allocate(size_t word_size, MetadataType mdtype) {
2596 // DumpSharedSpaces doesn't use class metadata area (yet)
2597 if (mdtype == ClassType && !DumpSharedSpaces) {
2598 return class_vsm()->allocate(word_size);
2599 } else {
2600 return vsm()->allocate(word_size);
2601 }
2602 }
2604 MetaWord* Metaspace::expand_and_allocate(size_t word_size, MetadataType mdtype) {
2605 MetaWord* result;
2606 MetaspaceGC::set_expand_after_GC(true);
2607 size_t before_inc = MetaspaceGC::capacity_until_GC();
2608 size_t delta_words = MetaspaceGC::delta_capacity_until_GC(word_size);
2609 MetaspaceGC::inc_capacity_until_GC(delta_words);
2610 if (PrintGCDetails && Verbose) {
2611 gclog_or_tty->print_cr("Increase capacity to GC from " SIZE_FORMAT
2612 " to " SIZE_FORMAT, before_inc, MetaspaceGC::capacity_until_GC());
2613 }
2615 result = allocate(word_size, mdtype);
2617 return result;
2618 }
2620 // Space allocated in the Metaspace. This may
2621 // be across several metadata virtual spaces.
2622 char* Metaspace::bottom() const {
2623 assert(DumpSharedSpaces, "only useful and valid for dumping shared spaces");
2624 return (char*)vsm()->current_chunk()->bottom();
2625 }
2627 size_t Metaspace::used_words(MetadataType mdtype) const {
2628 // return vsm()->allocation_total();
2629 return mdtype == ClassType ? class_vsm()->sum_used_in_chunks_in_use() :
2630 vsm()->sum_used_in_chunks_in_use(); // includes overhead!
2631 }
2633 size_t Metaspace::free_words(MetadataType mdtype) const {
2634 return mdtype == ClassType ? class_vsm()->sum_free_in_chunks_in_use() :
2635 vsm()->sum_free_in_chunks_in_use();
2636 }
2638 // Space capacity in the Metaspace. It includes
2639 // space in the list of chunks from which allocations
2640 // have been made. Don't include space in the global freelist and
2641 // in the space available in the dictionary which
2642 // is already counted in some chunk.
2643 size_t Metaspace::capacity_words(MetadataType mdtype) const {
2644 return mdtype == ClassType ? class_vsm()->sum_capacity_in_chunks_in_use() :
2645 vsm()->sum_capacity_in_chunks_in_use();
2646 }
2648 void Metaspace::deallocate(MetaWord* ptr, size_t word_size, bool is_class) {
2649 if (SafepointSynchronize::is_at_safepoint()) {
2650 assert(Thread::current()->is_VM_thread(), "should be the VM thread");
2651 // Don't take Heap_lock
2652 MutexLocker ml(vsm()->lock());
2653 if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
2654 // Dark matter. Too small for dictionary.
2655 #ifdef ASSERT
2656 Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
2657 #endif
2658 return;
2659 }
2660 if (is_class) {
2661 class_vsm()->deallocate(ptr, word_size);
2662 } else {
2663 vsm()->deallocate(ptr, word_size);
2664 }
2665 } else {
2666 MutexLocker ml(vsm()->lock());
2668 if (word_size < TreeChunk<Metablock, FreeList>::min_size()) {
2669 // Dark matter. Too small for dictionary.
2670 #ifdef ASSERT
2671 Copy::fill_to_words((HeapWord*)ptr, word_size, 0xf5f5f5f5);
2672 #endif
2673 return;
2674 }
2675 if (is_class) {
2676 class_vsm()->deallocate(ptr, word_size);
2677 } else {
2678 vsm()->deallocate(ptr, word_size);
2679 }
2680 }
2681 }
2683 Metablock* Metaspace::allocate(ClassLoaderData* loader_data, size_t word_size,
2684 bool read_only, MetadataType mdtype, TRAPS) {
2685 if (HAS_PENDING_EXCEPTION) {
2686 assert(false, "Should not allocate with exception pending");
2687 return NULL; // caller does a CHECK_NULL too
2688 }
2690 // SSS: Should we align the allocations and make sure the sizes are aligned.
2691 MetaWord* result = NULL;
2693 assert(loader_data != NULL, "Should never pass around a NULL loader_data. "
2694 "ClassLoaderData::the_null_class_loader_data() should have been used.");
2695 // Allocate in metaspaces without taking out a lock, because it deadlocks
2696 // with the SymbolTable_lock. Dumping is single threaded for now. We'll have
2697 // to revisit this for application class data sharing.
2698 if (DumpSharedSpaces) {
2699 if (read_only) {
2700 result = loader_data->ro_metaspace()->allocate(word_size, NonClassType);
2701 } else {
2702 result = loader_data->rw_metaspace()->allocate(word_size, NonClassType);
2703 }
2704 if (result == NULL) {
2705 report_out_of_shared_space(read_only ? SharedReadOnly : SharedReadWrite);
2706 }
2707 return Metablock::initialize(result, word_size);
2708 }
2710 result = loader_data->metaspace_non_null()->allocate(word_size, mdtype);
2712 if (result == NULL) {
2713 // Try to clean out some memory and retry.
2714 result =
2715 Universe::heap()->collector_policy()->satisfy_failed_metadata_allocation(
2716 loader_data, word_size, mdtype);
2718 // If result is still null, we are out of memory.
2719 if (result == NULL) {
2720 // -XX:+HeapDumpOnOutOfMemoryError and -XX:OnOutOfMemoryError support
2721 report_java_out_of_memory("Metadata space");
2723 if (JvmtiExport::should_post_resource_exhausted()) {
2724 JvmtiExport::post_resource_exhausted(
2725 JVMTI_RESOURCE_EXHAUSTED_OOM_ERROR,
2726 "Metadata space");
2727 }
2728 THROW_OOP_0(Universe::out_of_memory_error_perm_gen());
2729 }
2730 }
2731 return Metablock::initialize(result, word_size);
2732 }
2734 void Metaspace::print_on(outputStream* out) const {
2735 // Print both class virtual space counts and metaspace.
2736 if (Verbose) {
2737 vsm()->print_on(out);
2738 class_vsm()->print_on(out);
2739 }
2740 }
2742 #ifndef PRODUCT
2743 bool Metaspace::contains(const void * ptr) const {
2744 if (MetaspaceShared::is_in_shared_space(ptr)) {
2745 return true;
2746 }
2747 MutexLockerEx cl(SpaceManager::expand_lock(), Mutex::_no_safepoint_check_flag);
2748 return space_list()->contains(ptr) || class_space_list()->contains(ptr);
2749 }
2750 #endif
2752 void Metaspace::verify() {
2753 vsm()->verify();
2754 class_vsm()->verify();
2755 }
2757 void Metaspace::dump(outputStream* const out) const {
2758 if (UseMallocOnly) {
2759 // Just print usage for now
2760 out->print_cr("usage %d", used_words(Metaspace::NonClassType));
2761 }
2762 out->print_cr("\nVirtual space manager: " INTPTR_FORMAT, vsm());
2763 vsm()->dump(out);
2764 out->print_cr("\nClass space manager: " INTPTR_FORMAT, class_vsm());
2765 class_vsm()->dump(out);
2766 }