Fri, 21 Mar 2014 10:28:07 +0100
8036701: Add trace event when a metaspace throws out of memory error
Reviewed-by: stefank, mgerdin
1 /*
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24 #ifndef SHARE_VM_MEMORY_METASPACE_HPP
25 #define SHARE_VM_MEMORY_METASPACE_HPP
27 #include "memory/allocation.hpp"
28 #include "memory/memRegion.hpp"
29 #include "runtime/virtualspace.hpp"
30 #include "utilities/exceptions.hpp"
32 // Metaspace
33 //
34 // Metaspaces are Arenas for the VM's metadata.
35 // They are allocated one per class loader object, and one for the null
36 // bootstrap class loader
37 // Eventually for bootstrap loader we'll have a read-only section and read-write
38 // to write for DumpSharedSpaces and read for UseSharedSpaces
39 //
40 // block X ---+ +-------------------+
41 // | | Virtualspace |
42 // | | |
43 // | | |
44 // | |-------------------|
45 // | || Chunk |
46 // | || |
47 // | ||---------- |
48 // +------>||| block 0 | |
49 // ||---------- |
50 // ||| block 1 | |
51 // ||---------- |
52 // || |
53 // |-------------------|
54 // | |
55 // | |
56 // +-------------------+
57 //
59 class ChunkManager;
60 class ClassLoaderData;
61 class Metablock;
62 class Metachunk;
63 class MetaspaceTracer;
64 class MetaWord;
65 class Mutex;
66 class outputStream;
67 class SpaceManager;
68 class VirtualSpaceList;
70 // Metaspaces each have a SpaceManager and allocations
71 // are done by the SpaceManager. Allocations are done
72 // out of the current Metachunk. When the current Metachunk
73 // is exhausted, the SpaceManager gets a new one from
74 // the current VirtualSpace. When the VirtualSpace is exhausted
75 // the SpaceManager gets a new one. The SpaceManager
76 // also manages freelists of available Chunks.
77 //
78 // Currently the space manager maintains the list of
79 // virtual spaces and the list of chunks in use. Its
80 // allocate() method returns a block for use as a
81 // quantum of metadata.
83 class Metaspace : public CHeapObj<mtClass> {
84 friend class VMStructs;
85 friend class SpaceManager;
86 friend class VM_CollectForMetadataAllocation;
87 friend class MetaspaceGC;
88 friend class MetaspaceAux;
90 public:
91 enum MetadataType {
92 ClassType,
93 NonClassType,
94 MetadataTypeCount
95 };
96 enum MetaspaceType {
97 StandardMetaspaceType,
98 BootMetaspaceType,
99 ROMetaspaceType,
100 ReadWriteMetaspaceType,
101 AnonymousMetaspaceType,
102 ReflectionMetaspaceType
103 };
105 private:
106 void initialize(Mutex* lock, MetaspaceType type);
108 // Get the first chunk for a Metaspace. Used for
109 // special cases such as the boot class loader, reflection
110 // class loader and anonymous class loader.
111 Metachunk* get_initialization_chunk(MetadataType mdtype,
112 size_t chunk_word_size,
113 size_t chunk_bunch);
115 // Align up the word size to the allocation word size
116 static size_t align_word_size_up(size_t);
118 // Aligned size of the metaspace.
119 static size_t _compressed_class_space_size;
121 static size_t compressed_class_space_size() {
122 return _compressed_class_space_size;
123 }
124 static void set_compressed_class_space_size(size_t size) {
125 _compressed_class_space_size = size;
126 }
128 static size_t _first_chunk_word_size;
129 static size_t _first_class_chunk_word_size;
131 static size_t _commit_alignment;
132 static size_t _reserve_alignment;
134 SpaceManager* _vsm;
135 SpaceManager* vsm() const { return _vsm; }
137 SpaceManager* _class_vsm;
138 SpaceManager* class_vsm() const { return _class_vsm; }
140 // Allocate space for metadata of type mdtype. This is space
141 // within a Metachunk and is used by
142 // allocate(ClassLoaderData*, size_t, bool, MetadataType, TRAPS)
143 MetaWord* allocate(size_t word_size, MetadataType mdtype);
145 // Virtual Space lists for both classes and other metadata
146 static VirtualSpaceList* _space_list;
147 static VirtualSpaceList* _class_space_list;
149 static ChunkManager* _chunk_manager_metadata;
150 static ChunkManager* _chunk_manager_class;
152 static const MetaspaceTracer* _tracer;
154 public:
155 static VirtualSpaceList* space_list() { return _space_list; }
156 static VirtualSpaceList* class_space_list() { return _class_space_list; }
157 static VirtualSpaceList* get_space_list(MetadataType mdtype) {
158 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
159 return mdtype == ClassType ? class_space_list() : space_list();
160 }
162 static ChunkManager* chunk_manager_metadata() { return _chunk_manager_metadata; }
163 static ChunkManager* chunk_manager_class() { return _chunk_manager_class; }
164 static ChunkManager* get_chunk_manager(MetadataType mdtype) {
165 assert(mdtype != MetadataTypeCount, "MetadaTypeCount can't be used as mdtype");
166 return mdtype == ClassType ? chunk_manager_class() : chunk_manager_metadata();
167 }
169 static const MetaspaceTracer* tracer() { return _tracer; }
171 private:
172 // This is used by DumpSharedSpaces only, where only _vsm is used. So we will
173 // maintain a single list for now.
174 void record_allocation(void* ptr, MetaspaceObj::Type type, size_t word_size);
176 #ifdef _LP64
177 static void set_narrow_klass_base_and_shift(address metaspace_base, address cds_base);
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);
182 static void allocate_metaspace_compressed_klass_ptrs(char* requested_addr, address cds_base);
184 static void initialize_class_space(ReservedSpace rs);
185 #endif
187 class AllocRecord : public CHeapObj<mtClass> {
188 public:
189 AllocRecord(address ptr, MetaspaceObj::Type type, int byte_size)
190 : _next(NULL), _ptr(ptr), _type(type), _byte_size(byte_size) {}
191 AllocRecord *_next;
192 address _ptr;
193 MetaspaceObj::Type _type;
194 int _byte_size;
195 };
197 AllocRecord * _alloc_record_head;
198 AllocRecord * _alloc_record_tail;
200 size_t class_chunk_size(size_t word_size);
202 public:
204 Metaspace(Mutex* lock, MetaspaceType type);
205 ~Metaspace();
207 static void ergo_initialize();
208 static void global_initialize();
210 static size_t first_chunk_word_size() { return _first_chunk_word_size; }
211 static size_t first_class_chunk_word_size() { return _first_class_chunk_word_size; }
213 static size_t reserve_alignment() { return _reserve_alignment; }
214 static size_t reserve_alignment_words() { return _reserve_alignment / BytesPerWord; }
215 static size_t commit_alignment() { return _commit_alignment; }
216 static size_t commit_alignment_words() { return _commit_alignment / BytesPerWord; }
218 char* bottom() const;
219 size_t used_words_slow(MetadataType mdtype) const;
220 size_t free_words_slow(MetadataType mdtype) const;
221 size_t capacity_words_slow(MetadataType mdtype) const;
223 size_t used_bytes_slow(MetadataType mdtype) const;
224 size_t capacity_bytes_slow(MetadataType mdtype) const;
226 static MetaWord* allocate(ClassLoaderData* loader_data, size_t word_size,
227 bool read_only, MetaspaceObj::Type type, TRAPS);
228 void deallocate(MetaWord* ptr, size_t byte_size, bool is_class);
230 MetaWord* expand_and_allocate(size_t size,
231 MetadataType mdtype);
233 bool contains(const void* ptr);
234 void dump(outputStream* const out) const;
236 // Free empty virtualspaces
237 static void purge(MetadataType mdtype);
238 static void purge();
240 static void report_metadata_oome(ClassLoaderData* loader_data, size_t word_size,
241 MetaspaceObj::Type type, MetadataType mdtype, TRAPS);
243 static const char* metadata_type_name(Metaspace::MetadataType mdtype);
245 void print_on(outputStream* st) const;
246 // Debugging support
247 void verify();
249 class AllocRecordClosure : public StackObj {
250 public:
251 virtual void doit(address ptr, MetaspaceObj::Type type, int byte_size) = 0;
252 };
254 void iterate(AllocRecordClosure *closure);
256 // Return TRUE only if UseCompressedClassPointers is True and DumpSharedSpaces is False.
257 static bool using_class_space() {
258 return NOT_LP64(false) LP64_ONLY(UseCompressedClassPointers && !DumpSharedSpaces);
259 }
261 static bool is_class_space_allocation(MetadataType mdType) {
262 return mdType == ClassType && using_class_space();
263 }
265 };
267 class MetaspaceAux : AllStatic {
268 static size_t free_chunks_total_words(Metaspace::MetadataType mdtype);
270 // These methods iterate over the classloader data graph
271 // for the given Metaspace type. These are slow.
272 static size_t used_bytes_slow(Metaspace::MetadataType mdtype);
273 static size_t free_bytes_slow(Metaspace::MetadataType mdtype);
274 static size_t capacity_bytes_slow(Metaspace::MetadataType mdtype);
275 static size_t capacity_bytes_slow();
277 // Running sum of space in all Metachunks that has been
278 // allocated to a Metaspace. This is used instead of
279 // iterating over all the classloaders. One for each
280 // type of Metadata
281 static size_t _allocated_capacity_words[Metaspace:: MetadataTypeCount];
282 // Running sum of space in all Metachunks that have
283 // are being used for metadata. One for each
284 // type of Metadata.
285 static size_t _allocated_used_words[Metaspace:: MetadataTypeCount];
287 public:
288 // Decrement and increment _allocated_capacity_words
289 static void dec_capacity(Metaspace::MetadataType type, size_t words);
290 static void inc_capacity(Metaspace::MetadataType type, size_t words);
292 // Decrement and increment _allocated_used_words
293 static void dec_used(Metaspace::MetadataType type, size_t words);
294 static void inc_used(Metaspace::MetadataType type, size_t words);
296 // Total of space allocated to metadata in all Metaspaces.
297 // This sums the space used in each Metachunk by
298 // iterating over the classloader data graph
299 static size_t used_bytes_slow() {
300 return used_bytes_slow(Metaspace::ClassType) +
301 used_bytes_slow(Metaspace::NonClassType);
302 }
304 // Used by MetaspaceCounters
305 static size_t free_chunks_total_words();
306 static size_t free_chunks_total_bytes();
307 static size_t free_chunks_total_bytes(Metaspace::MetadataType mdtype);
309 static size_t allocated_capacity_words(Metaspace::MetadataType mdtype) {
310 return _allocated_capacity_words[mdtype];
311 }
312 static size_t allocated_capacity_words() {
313 return allocated_capacity_words(Metaspace::NonClassType) +
314 allocated_capacity_words(Metaspace::ClassType);
315 }
316 static size_t allocated_capacity_bytes(Metaspace::MetadataType mdtype) {
317 return allocated_capacity_words(mdtype) * BytesPerWord;
318 }
319 static size_t allocated_capacity_bytes() {
320 return allocated_capacity_words() * BytesPerWord;
321 }
323 static size_t allocated_used_words(Metaspace::MetadataType mdtype) {
324 return _allocated_used_words[mdtype];
325 }
326 static size_t allocated_used_words() {
327 return allocated_used_words(Metaspace::NonClassType) +
328 allocated_used_words(Metaspace::ClassType);
329 }
330 static size_t allocated_used_bytes(Metaspace::MetadataType mdtype) {
331 return allocated_used_words(mdtype) * BytesPerWord;
332 }
333 static size_t allocated_used_bytes() {
334 return allocated_used_words() * BytesPerWord;
335 }
337 static size_t free_bytes();
338 static size_t free_bytes(Metaspace::MetadataType mdtype);
340 static size_t reserved_bytes(Metaspace::MetadataType mdtype);
341 static size_t reserved_bytes() {
342 return reserved_bytes(Metaspace::ClassType) +
343 reserved_bytes(Metaspace::NonClassType);
344 }
346 static size_t committed_bytes(Metaspace::MetadataType mdtype);
347 static size_t committed_bytes() {
348 return committed_bytes(Metaspace::ClassType) +
349 committed_bytes(Metaspace::NonClassType);
350 }
352 static size_t min_chunk_size_words();
353 static size_t min_chunk_size_bytes() {
354 return min_chunk_size_words() * BytesPerWord;
355 }
357 // Print change in used metadata.
358 static void print_metaspace_change(size_t prev_metadata_used);
359 static void print_on(outputStream * out);
360 static void print_on(outputStream * out, Metaspace::MetadataType mdtype);
362 static void print_class_waste(outputStream* out);
363 static void print_waste(outputStream* out);
364 static void dump(outputStream* out);
365 static void verify_free_chunks();
366 // Checks that the values returned by allocated_capacity_bytes() and
367 // capacity_bytes_slow() are the same.
368 static void verify_capacity();
369 static void verify_used();
370 static void verify_metrics();
371 };
373 // Metaspace are deallocated when their class loader are GC'ed.
374 // This class implements a policy for inducing GC's to recover
375 // Metaspaces.
377 class MetaspaceGC : AllStatic {
379 // The current high-water-mark for inducing a GC.
380 // When committed memory of all metaspaces reaches this value,
381 // a GC is induced and the value is increased. Size is in bytes.
382 static volatile intptr_t _capacity_until_GC;
384 // For a CMS collection, signal that a concurrent collection should
385 // be started.
386 static bool _should_concurrent_collect;
388 static uint _shrink_factor;
390 static size_t shrink_factor() { return _shrink_factor; }
391 void set_shrink_factor(uint v) { _shrink_factor = v; }
393 public:
395 static void initialize() { _capacity_until_GC = MetaspaceSize; }
397 static size_t capacity_until_GC();
398 static size_t inc_capacity_until_GC(size_t v);
399 static size_t dec_capacity_until_GC(size_t v);
401 static bool should_concurrent_collect() { return _should_concurrent_collect; }
402 static void set_should_concurrent_collect(bool v) {
403 _should_concurrent_collect = v;
404 }
406 // The amount to increase the high-water-mark (_capacity_until_GC)
407 static size_t delta_capacity_until_GC(size_t bytes);
409 // Tells if we have can expand metaspace without hitting set limits.
410 static bool can_expand(size_t words, bool is_class);
412 // Returns amount that we can expand without hitting a GC,
413 // measured in words.
414 static size_t allowed_expansion();
416 // Calculate the new high-water mark at which to induce
417 // a GC.
418 static void compute_new_size();
419 };
421 #endif // SHARE_VM_MEMORY_METASPACE_HPP