1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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23 */
24#ifndef SHARE_MEMORY_METASPACE_HPP
25#define SHARE_MEMORY_METASPACE_HPP
26
27#include "memory/allocation.hpp"
28#include "memory/memRegion.hpp"
29#include "memory/metaspaceChunkFreeListSummary.hpp"
30#include "memory/virtualspace.hpp"
31#include "utilities/exceptions.hpp"
32
33// Metaspace
34//
35// Metaspaces are Arenas for the VM's metadata.
36// They are allocated one per class loader object, and one for the null
37// bootstrap class loader
38//
39// block X ---+ +-------------------+
40// | | Virtualspace |
41// | | |
42// | | |
43// | |-------------------|
44// | || Chunk |
45// | || |
46// | ||---------- |
47// +------>||| block 0 | |
48// ||---------- |
49// ||| block 1 | |
50// ||---------- |
51// || |
52// |-------------------|
53// | |
54// | |
55// +-------------------+
56//
57
58class ClassLoaderData;
59class MetaspaceTracer;
60class Mutex;
61class outputStream;
62
63class CollectedHeap;
64
65namespace metaspace {
66 class ChunkManager;
67 class ClassLoaderMetaspaceStatistics;
68 class Metablock;
69 class Metachunk;
70 class PrintCLDMetaspaceInfoClosure;
71 class SpaceManager;
72 class VirtualSpaceList;
73 class VirtualSpaceNode;
74}
75
76// Metaspaces each have a SpaceManager and allocations
77// are done by the SpaceManager. Allocations are done
78// out of the current Metachunk. When the current Metachunk
79// is exhausted, the SpaceManager gets a new one from
80// the current VirtualSpace. When the VirtualSpace is exhausted
81// the SpaceManager gets a new one. The SpaceManager
82// also manages freelists of available Chunks.
83//
84// Currently the space manager maintains the list of
85// virtual spaces and the list of chunks in use. Its
86// allocate() method returns a block for use as a
87// quantum of metadata.
88
89// Namespace for important central static functions
90// (auxiliary stuff goes into MetaspaceUtils)
91class Metaspace : public AllStatic {
92
93 friend class MetaspaceShared;
94
95 public:
96 enum MetadataType {
97 ClassType,
98 NonClassType,
99 MetadataTypeCount
100 };
101 enum MetaspaceType {
102 ZeroMetaspaceType = 0,
103 StandardMetaspaceType = ZeroMetaspaceType,
104 BootMetaspaceType = StandardMetaspaceType + 1,
105 UnsafeAnonymousMetaspaceType = BootMetaspaceType + 1,
106 ReflectionMetaspaceType = UnsafeAnonymousMetaspaceType + 1,
107 MetaspaceTypeCount
108 };
109
110 private:
111
112 // Align up the word size to the allocation word size
113 static size_t align_word_size_up(size_t);
114
115 // Aligned size of the metaspace.
116 static size_t _compressed_class_space_size;
117
118 static size_t compressed_class_space_size() {
119 return _compressed_class_space_size;
120 }
121
122 static void set_compressed_class_space_size(size_t size) {
123 _compressed_class_space_size = size;
124 }
125
126 static size_t _first_chunk_word_size;
127 static size_t _first_class_chunk_word_size;
128
129 static size_t _commit_alignment;
130 static size_t _reserve_alignment;
131 DEBUG_ONLY(static bool _frozen;)
132
133 // Virtual Space lists for both classes and other metadata
134 static metaspace::VirtualSpaceList* _space_list;
135 static metaspace::VirtualSpaceList* _class_space_list;
136
137 static metaspace::ChunkManager* _chunk_manager_metadata;
138 static metaspace::ChunkManager* _chunk_manager_class;
139
140 static const MetaspaceTracer* _tracer;
141
142 public:
143 static metaspace::VirtualSpaceList* space_list() { return _space_list; }
144 static metaspace::VirtualSpaceList* class_space_list() { return _class_space_list; }
145 static metaspace::VirtualSpaceList* get_space_list(MetadataType mdtype) {
146 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
147 return mdtype == ClassType ? class_space_list() : space_list();
148 }
149
150 static metaspace::ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
151 static metaspace::ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
152 static metaspace::ChunkManager* get_chunk_manager(MetadataType mdtype) {
153 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
154 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
155 }
156
157 // convenience function
158 static metaspace::ChunkManager* get_chunk_manager(bool is_class) {
159 return is_class ? chunk_manager_class() : chunk_manager_metadata();
160 }
161
162 static const MetaspaceTracer* tracer() { return _tracer; }
163 static void freeze() {
164 assert(DumpSharedSpaces, "sanity");
165 DEBUG_ONLY(_frozen = true;)
166 }
167 static void assert_not_frozen() {
168 assert(!_frozen, "sanity");
169 }
170#ifdef _LP64
171 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
172#endif
173
174 private:
175
176#ifdef _LP64
177 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
178
179 // Returns true if can use CDS with metaspace allocated as specified address.
180 static bool can_use_cds_with_metaspace_addr(char* metaspace_base, address cds_base);
181
182 static void initialize_class_space(ReservedSpace rs);
183#endif
184
185 public:
186
187 static void ergo_initialize();
188 static void global_initialize();
189 static void post_initialize();
190
191 static void verify_global_initialization();
192
193 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
194 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
195
196 static size_t reserve_alignment() { return _reserve_alignment; }
197 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
198 static size_t commit_alignment() { return _commit_alignment; }
199 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
200
201 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
202 MetaspaceObj::Type type, TRAPS);
203
204 static bool contains(const void* ptr);
205 static bool contains_non_shared(const void* ptr);
206
207 // Free empty virtualspaces
208 static void purge(MetadataType mdtype);
209 static void purge();
210
211 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
212 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
213
214 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
215
216 static void print_compressed_class_space(outputStream* st, const char* requested_addr = 0) NOT_LP64({});
217
218 // Return TRUE only if UseCompressedClassPointers is True.
219 static bool using_class_space() {
220 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers);
221 }
222
223 static bool is_class_space_allocation(MetadataType mdType) {
224 return mdType == ClassType && using_class_space();
225 }
226
227};
228
229// Manages the metaspace portion belonging to a class loader
230class ClassLoaderMetaspace : public CHeapObj<mtClass> {
231 friend class CollectedHeap; // For expand_and_allocate()
232 friend class ZCollectedHeap; // For expand_and_allocate()
233 friend class ShenandoahHeap; // For expand_and_allocate()
234 friend class Metaspace;
235 friend class MetaspaceUtils;
236 friend class metaspace::PrintCLDMetaspaceInfoClosure;
237 friend class VM_CollectForMetadataAllocation; // For expand_and_allocate()
238
239 private:
240
241 void initialize(Mutex* lock, Metaspace::MetaspaceType type);
242
243 // Initialize the first chunk for a Metaspace. Used for
244 // special cases such as the boot class loader, reflection
245 // class loader and anonymous class loader.
246 void initialize_first_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
247 metaspace::Metachunk* get_initialization_chunk(Metaspace::MetaspaceType type, Metaspace::MetadataType mdtype);
248
249 const Metaspace::MetaspaceType _space_type;
250 Mutex* const _lock;
251 metaspace::SpaceManager* _vsm;
252 metaspace::SpaceManager* _class_vsm;
253
254 metaspace::SpaceManager* vsm() const { return _vsm; }
255 metaspace::SpaceManager* class_vsm() const { return _class_vsm; }
256 metaspace::SpaceManager* get_space_manager(Metaspace::MetadataType mdtype) {
257 assert(mdtype != Metaspace::MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
258 return mdtype == Metaspace::ClassType ? class_vsm() : vsm();
259 }
260
261 Mutex* lock() const { return _lock; }
262
263 MetaWord* expand_and_allocate(size_t size, Metaspace::MetadataType mdtype);
264
265 size_t class_chunk_size(size_t word_size);
266
267 // Adds to the given statistic object. Must be locked with CLD metaspace lock.
268 void add_to_statistics_locked(metaspace::ClassLoaderMetaspaceStatistics* out) const;
269
270 Metaspace::MetaspaceType space_type() const { return _space_type; }
271
272 public:
273
274 ClassLoaderMetaspace(Mutex* lock, Metaspace::MetaspaceType type);
275 ~ClassLoaderMetaspace();
276
277 // Allocate space for metadata of type mdtype. This is space
278 // within a Metachunk and is used by
279 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
280 MetaWord* allocate(size_t word_size, Metaspace::MetadataType mdtype);
281
282 size_t allocated_blocks_bytes() const;
283 size_t allocated_chunks_bytes() const;
284
285 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
286
287 void print_on(outputStream* st) const;
288 // Debugging support
289 void verify();
290
291 // Adds to the given statistic object. Will lock with CLD metaspace lock.
292 void add_to_statistics(metaspace::ClassLoaderMetaspaceStatistics* out) const;
293
294}; // ClassLoaderMetaspace
295
296class MetaspaceUtils : AllStatic {
297
298 // Spacemanager updates running counters.
299 friend class metaspace::SpaceManager;
300
301 // Special access for error reporting (checks without locks).
302 friend class oopDesc;
303 friend class Klass;
304
305 // Running counters for statistics concerning in-use chunks.
306 // Note: capacity = used + free + waste + overhead. Note that we do not
307 // count free and waste. Their sum can be deduces from the three other values.
308 // For more details, one should call print_report() from within a safe point.
309 static size_t _capacity_words [Metaspace:: MetadataTypeCount];
310 static size_t _overhead_words [Metaspace:: MetadataTypeCount];
311 static volatile size_t _used_words [Metaspace:: MetadataTypeCount];
312
313 // Atomically decrement or increment in-use statistic counters
314 static void dec_capacity(Metaspace::MetadataType mdtype, size_t words);
315 static void inc_capacity(Metaspace::MetadataType mdtype, size_t words);
316 static void dec_used(Metaspace::MetadataType mdtype, size_t words);
317 static void inc_used(Metaspace::MetadataType mdtype, size_t words);
318 static void dec_overhead(Metaspace::MetadataType mdtype, size_t words);
319 static void inc_overhead(Metaspace::MetadataType mdtype, size_t words);
320
321
322 // Getters for the in-use counters.
323 static size_t capacity_words(Metaspace::MetadataType mdtype) { return _capacity_words[mdtype]; }
324 static size_t used_words(Metaspace::MetadataType mdtype) { return _used_words[mdtype]; }
325 static size_t overhead_words(Metaspace::MetadataType mdtype) { return _overhead_words[mdtype]; }
326
327 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
328
329 // Helper for print_xx_report.
330 static void print_vs(outputStream* out, size_t scale);
331
332public:
333
334 // Collect used metaspace statistics. This involves walking the CLDG. The resulting
335 // output will be the accumulated values for all live metaspaces.
336 // Note: method does not do any locking.
337 static void collect_statistics(metaspace::ClassLoaderMetaspaceStatistics* out);
338
339 // Used by MetaspaceCounters
340 static size_t free_chunks_total_words();
341 static size_t free_chunks_total_bytes();
342 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
343
344 static size_t capacity_words() {
345 return capacity_words(Metaspace::NonClassType) +
346 capacity_words(Metaspace::ClassType);
347 }
348 static size_t capacity_bytes(Metaspace::MetadataType mdtype) {
349 return capacity_words(mdtype) * BytesPerWord;
350 }
351 static size_t capacity_bytes() {
352 return capacity_words() * BytesPerWord;
353 }
354
355 static size_t used_words() {
356 return used_words(Metaspace::NonClassType) +
357 used_words(Metaspace::ClassType);
358 }
359 static size_t used_bytes(Metaspace::MetadataType mdtype) {
360 return used_words(mdtype) * BytesPerWord;
361 }
362 static size_t used_bytes() {
363 return used_words() * BytesPerWord;
364 }
365
366 // Space committed but yet unclaimed by any class loader.
367 static size_t free_in_vs_bytes();
368 static size_t free_in_vs_bytes(Metaspace::MetadataType mdtype);
369
370 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
371 static size_t reserved_bytes() {
372 return reserved_bytes(Metaspace::ClassType) +
373 reserved_bytes(Metaspace::NonClassType);
374 }
375
376 static size_t committed_bytes(Metaspace::MetadataType mdtype);
377 static size_t committed_bytes() {
378 return committed_bytes(Metaspace::ClassType) +
379 committed_bytes(Metaspace::NonClassType);
380 }
381
382 static size_t min_chunk_size_words();
383
384 // Flags for print_report().
385 enum ReportFlag {
386 // Show usage by class loader.
387 rf_show_loaders = (1 << 0),
388 // Breaks report down by chunk type (small, medium, ...).
389 rf_break_down_by_chunktype = (1 << 1),
390 // Breaks report down by space type (anonymous, reflection, ...).
391 rf_break_down_by_spacetype = (1 << 2),
392 // Print details about the underlying virtual spaces.
393 rf_show_vslist = (1 << 3),
394 // Print metaspace map.
395 rf_show_vsmap = (1 << 4),
396 // If show_loaders: show loaded classes for each loader.
397 rf_show_classes = (1 << 5)
398 };
399
400 // This will print out a basic metaspace usage report but
401 // unlike print_report() is guaranteed not to lock or to walk the CLDG.
402 static void print_basic_report(outputStream* st, size_t scale);
403
404 // Prints a report about the current metaspace state.
405 // Optional parts can be enabled via flags.
406 // Function will walk the CLDG and will lock the expand lock; if that is not
407 // convenient, use print_basic_report() instead.
408 static void print_report(outputStream* out, size_t scale = 0, int flags = 0);
409
410 static bool has_chunk_free_list(Metaspace::MetadataType mdtype);
411 static MetaspaceChunkFreeListSummary chunk_free_list_summary(Metaspace::MetadataType mdtype);
412
413 // Print change in used metadata.
414 static void print_metaspace_change(size_t prev_metadata_used);
415 static void print_on(outputStream * out);
416
417 // Prints an ASCII representation of the given space.
418 static void print_metaspace_map(outputStream* out, Metaspace::MetadataType mdtype);
419
420 static void dump(outputStream* out);
421 static void verify_free_chunks();
422 // Check internal counters (capacity, used).
423 static void verify_metrics();
424};
425
426// Metaspace are deallocated when their class loader are GC'ed.
427// This class implements a policy for inducing GC's to recover
428// Metaspaces.
429
430class MetaspaceGC : AllStatic {
431
432 // The current high-water-mark for inducing a GC.
433 // When committed memory of all metaspaces reaches this value,
434 // a GC is induced and the value is increased. Size is in bytes.
435 static volatile size_t _capacity_until_GC;
436
437 // For a CMS collection, signal that a concurrent collection should
438 // be started.
439 static bool _should_concurrent_collect;
440
441 static uint _shrink_factor;
442
443 static size_t shrink_factor() { return _shrink_factor; }
444 void set_shrink_factor(uint v) { _shrink_factor = v; }
445
446 public:
447
448 static void initialize();
449 static void post_initialize();
450
451 static size_t capacity_until_GC();
452 static bool inc_capacity_until_GC(size_t v,
453 size_t* new_cap_until_GC = NULL,
454 size_t* old_cap_until_GC = NULL,
455 bool* can_retry = NULL);
456 static size_t dec_capacity_until_GC(size_t v);
457
458 static bool should_concurrent_collect() { return _should_concurrent_collect; }
459 static void set_should_concurrent_collect(bool v) {
460 _should_concurrent_collect = v;
461 }
462
463 // The amount to increase the high-water-mark (_capacity_until_GC)
464 static size_t delta_capacity_until_GC(size_t bytes);
465
466 // Tells if we have can expand metaspace without hitting set limits.
467 static bool can_expand(size_t words, bool is_class);
468
469 // Returns amount that we can expand without hitting a GC,
470 // measured in words.
471 static size_t allowed_expansion();
472
473 // Calculate the new high-water mark at which to induce
474 // a GC.
475 static void compute_new_size();
476};
477
478#endif // SHARE_MEMORY_METASPACE_HPP
479