1 /*
2 * Copyright (c) 2017, 2018, 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
25 #include "precompiled.hpp"
26 #include "memory/allocation.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/metaspaceShared.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "memory/universe.hpp"
31 #include "runtime/atomic.hpp"
32 #include "runtime/os.hpp"
33 #include "runtime/task.hpp"
34 #include "runtime/threadCritical.hpp"
35 #include "services/memTracker.hpp"
36 #include "utilities/ostream.hpp"
37
38 //--------------------------------------------------------------------------------------
39 // ChunkPool implementation
40
41 // MT-safe pool of chunks to reduce malloc/free thrashing
42 // NB: not using Mutex because pools are used before Threads are initialized
43 class ChunkPool: public CHeapObj<mtInternal> {
44 Chunk* _first; // first cached Chunk; its first word points to next chunk
45 size_t _num_chunks; // number of unused chunks in pool
46 size_t _num_used; // number of chunks currently checked out
47 const size_t _size; // size of each chunk (must be uniform)
48
49 // Our four static pools
50 static ChunkPool* _large_pool;
51 static ChunkPool* _medium_pool;
52 static ChunkPool* _small_pool;
53 static ChunkPool* _tiny_pool;
54
55 // return first element or null
56 void* get_first() {
57 Chunk* c = _first;
58 if (_first) {
59 _first = _first->next();
60 _num_chunks--;
61 }
62 return c;
63 }
64
65 public:
66 // All chunks in a ChunkPool has the same size
67 ChunkPool(size_t size) : _size(size) { _first = NULL; _num_chunks = _num_used = 0; }
68
69 // Allocate a new chunk from the pool (might expand the pool)
70 NOINLINE void* allocate(size_t bytes, AllocFailType alloc_failmode) {
71 assert(bytes == _size, "bad size");
72 void* p = NULL;
73 // No VM lock can be taken inside ThreadCritical lock, so os::malloc
74 // should be done outside ThreadCritical lock due to NMT
75 { ThreadCritical tc;
76 _num_used++;
77 p = get_first();
78 }
79 if (p == NULL) p = os::malloc(bytes, mtChunk, CURRENT_PC);
80 if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
81 vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "ChunkPool::allocate");
82 }
83 return p;
84 }
85
86 // Return a chunk to the pool
87 void free(Chunk* chunk) {
88 assert(chunk->length() + Chunk::aligned_overhead_size() == _size, "bad size");
89 ThreadCritical tc;
90 _num_used--;
91
92 // Add chunk to list
93 chunk->set_next(_first);
94 _first = chunk;
95 _num_chunks++;
96 }
97
98 // Prune the pool
99 void free_all_but(size_t n) {
100 Chunk* cur = NULL;
101 Chunk* next;
102 {
103 // if we have more than n chunks, free all of them
104 ThreadCritical tc;
105 if (_num_chunks > n) {
106 // free chunks at end of queue, for better locality
107 cur = _first;
108 for (size_t i = 0; i < (n - 1) && cur != NULL; i++) cur = cur->next();
109
110 if (cur != NULL) {
111 next = cur->next();
112 cur->set_next(NULL);
113 cur = next;
114
115 // Free all remaining chunks while in ThreadCritical lock
116 // so NMT adjustment is stable.
117 while(cur != NULL) {
118 next = cur->next();
119 os::free(cur);
120 _num_chunks--;
121 cur = next;
122 }
123 }
124 }
125 }
126 }
127
128 // Accessors to preallocated pool's
129 static ChunkPool* large_pool() { assert(_large_pool != NULL, "must be initialized"); return _large_pool; }
130 static ChunkPool* medium_pool() { assert(_medium_pool != NULL, "must be initialized"); return _medium_pool; }
131 static ChunkPool* small_pool() { assert(_small_pool != NULL, "must be initialized"); return _small_pool; }
132 static ChunkPool* tiny_pool() { assert(_tiny_pool != NULL, "must be initialized"); return _tiny_pool; }
133
134 static void initialize() {
135 _large_pool = new ChunkPool(Chunk::size + Chunk::aligned_overhead_size());
136 _medium_pool = new ChunkPool(Chunk::medium_size + Chunk::aligned_overhead_size());
137 _small_pool = new ChunkPool(Chunk::init_size + Chunk::aligned_overhead_size());
138 _tiny_pool = new ChunkPool(Chunk::tiny_size + Chunk::aligned_overhead_size());
139 }
140
141 static void clean() {
142 enum { BlocksToKeep = 5 };
143 _tiny_pool->free_all_but(BlocksToKeep);
144 _small_pool->free_all_but(BlocksToKeep);
145 _medium_pool->free_all_but(BlocksToKeep);
146 _large_pool->free_all_but(BlocksToKeep);
147 }
148 };
149
150 ChunkPool* ChunkPool::_large_pool = NULL;
151 ChunkPool* ChunkPool::_medium_pool = NULL;
152 ChunkPool* ChunkPool::_small_pool = NULL;
153 ChunkPool* ChunkPool::_tiny_pool = NULL;
154
155 void chunkpool_init() {
156 ChunkPool::initialize();
157 }
158
159 void
160 Chunk::clean_chunk_pool() {
161 ChunkPool::clean();
162 }
163
164
165 //--------------------------------------------------------------------------------------
166 // ChunkPoolCleaner implementation
167 //
168
169 class ChunkPoolCleaner : public PeriodicTask {
170 enum { CleaningInterval = 5000 }; // cleaning interval in ms
171
172 public:
173 ChunkPoolCleaner() : PeriodicTask(CleaningInterval) {}
174 void task() {
175 ChunkPool::clean();
176 }
177 };
178
179 //--------------------------------------------------------------------------------------
180 // Chunk implementation
181
182 void* Chunk::operator new (size_t requested_size, AllocFailType alloc_failmode, size_t length) throw() {
183 // requested_size is equal to sizeof(Chunk) but in order for the arena
184 // allocations to come out aligned as expected the size must be aligned
185 // to expected arena alignment.
186 // expect requested_size but if sizeof(Chunk) doesn't match isn't proper size we must align it.
187 assert(ARENA_ALIGN(requested_size) == aligned_overhead_size(), "Bad alignment");
188 size_t bytes = ARENA_ALIGN(requested_size) + length;
189 switch (length) {
190 case Chunk::size: return ChunkPool::large_pool()->allocate(bytes, alloc_failmode);
191 case Chunk::medium_size: return ChunkPool::medium_pool()->allocate(bytes, alloc_failmode);
192 case Chunk::init_size: return ChunkPool::small_pool()->allocate(bytes, alloc_failmode);
193 case Chunk::tiny_size: return ChunkPool::tiny_pool()->allocate(bytes, alloc_failmode);
194 default: {
195 void* p = os::malloc(bytes, mtChunk, CALLER_PC);
196 if (p == NULL && alloc_failmode == AllocFailStrategy::EXIT_OOM) {
197 vm_exit_out_of_memory(bytes, OOM_MALLOC_ERROR, "Chunk::new");
198 }
199 return p;
200 }
201 }
202 }
203
204 void Chunk::operator delete(void* p) {
205 Chunk* c = (Chunk*)p;
206 switch (c->length()) {
207 case Chunk::size: ChunkPool::large_pool()->free(c); break;
208 case Chunk::medium_size: ChunkPool::medium_pool()->free(c); break;
209 case Chunk::init_size: ChunkPool::small_pool()->free(c); break;
210 case Chunk::tiny_size: ChunkPool::tiny_pool()->free(c); break;
211 default:
212 ThreadCritical tc; // Free chunks under TC lock so that NMT adjustment is stable.
213 os::free(c);
214 }
215 }
216
217 Chunk::Chunk(size_t length) : _len(length) {
218 _next = NULL; // Chain on the linked list
219 }
220
221 void Chunk::chop() {
222 Chunk *k = this;
223 while( k ) {
224 Chunk *tmp = k->next();
225 // clear out this chunk (to detect allocation bugs)
226 if (ZapResourceArea) memset(k->bottom(), badResourceValue, k->length());
227 delete k; // Free chunk (was malloc'd)
228 k = tmp;
229 }
230 }
231
232 void Chunk::next_chop() {
233 _next->chop();
234 _next = NULL;
235 }
236
237 void Chunk::start_chunk_pool_cleaner_task() {
238 #ifdef ASSERT
239 static bool task_created = false;
240 assert(!task_created, "should not start chuck pool cleaner twice");
241 task_created = true;
242 #endif
243 ChunkPoolCleaner* cleaner = new ChunkPoolCleaner();
244 cleaner->enroll();
245 }
246
247 //------------------------------Arena------------------------------------------
248
249 Arena::Arena(MEMFLAGS flag, size_t init_size) : _flags(flag), _size_in_bytes(0) {
250 size_t round_size = (sizeof (char *)) - 1;
251 init_size = (init_size+round_size) & ~round_size;
252 _first = _chunk = new (AllocFailStrategy::EXIT_OOM, init_size) Chunk(init_size);
253 _hwm = _chunk->bottom(); // Save the cached hwm, max
254 _max = _chunk->top();
255 MemTracker::record_new_arena(flag);
256 set_size_in_bytes(init_size);
257 }
258
259 Arena::Arena(MEMFLAGS flag) : _flags(flag), _size_in_bytes(0) {
260 _first = _chunk = new (AllocFailStrategy::EXIT_OOM, Chunk::init_size) Chunk(Chunk::init_size);
261 _hwm = _chunk->bottom(); // Save the cached hwm, max
262 _max = _chunk->top();
263 MemTracker::record_new_arena(flag);
264 set_size_in_bytes(Chunk::init_size);
265 }
266
267 Arena *Arena::move_contents(Arena *copy) {
268 copy->destruct_contents();
269 copy->_chunk = _chunk;
270 copy->_hwm = _hwm;
271 copy->_max = _max;
272 copy->_first = _first;
273
274 // workaround rare racing condition, which could double count
275 // the arena size by native memory tracking
276 size_t size = size_in_bytes();
277 set_size_in_bytes(0);
278 copy->set_size_in_bytes(size);
279 // Destroy original arena
280 reset();
281 return copy; // Return Arena with contents
282 }
283
284 Arena::~Arena() {
285 destruct_contents();
286 MemTracker::record_arena_free(_flags);
287 }
288
289 void* Arena::operator new(size_t size) throw() {
290 assert(false, "Use dynamic memory type binding");
291 return NULL;
292 }
293
294 void* Arena::operator new (size_t size, const std::nothrow_t& nothrow_constant) throw() {
295 assert(false, "Use dynamic memory type binding");
296 return NULL;
297 }
298
299 // dynamic memory type binding
300 void* Arena::operator new(size_t size, MEMFLAGS flags) throw() {
301 return (void *) AllocateHeap(size, flags, CALLER_PC);
302 }
303
304 void* Arena::operator new(size_t size, const std::nothrow_t& nothrow_constant, MEMFLAGS flags) throw() {
305 return (void*)AllocateHeap(size, flags, CALLER_PC, AllocFailStrategy::RETURN_NULL);
306 }
307
308 void Arena::operator delete(void* p) {
309 FreeHeap(p);
310 }
311
312 // Destroy this arenas contents and reset to empty
313 void Arena::destruct_contents() {
314 if (UseMallocOnly && _first != NULL) {
315 char* end = _first->next() ? _first->top() : _hwm;
316 free_malloced_objects(_first, _first->bottom(), end, _hwm);
317 }
318 // reset size before chop to avoid a rare racing condition
319 // that can have total arena memory exceed total chunk memory
320 set_size_in_bytes(0);
321 _first->chop();
322 reset();
323 }
324
325 // This is high traffic method, but many calls actually don't
326 // change the size
327 void Arena::set_size_in_bytes(size_t size) {
328 if (_size_in_bytes != size) {
329 long delta = (long)(size - size_in_bytes());
330 _size_in_bytes = size;
331 MemTracker::record_arena_size_change(delta, _flags);
332 }
333 }
334
335 // Total of all Chunks in arena
336 size_t Arena::used() const {
337 size_t sum = _chunk->length() - (_max-_hwm); // Size leftover in this Chunk
338 Chunk *k = _first;
339 while( k != _chunk) { // Whilst have Chunks in a row
340 sum += k->length(); // Total size of this Chunk
341 k = k->next(); // Bump along to next Chunk
342 }
343 return sum; // Return total consumed space.
344 }
345
346 void Arena::signal_out_of_memory(size_t sz, const char* whence) const {
347 vm_exit_out_of_memory(sz, OOM_MALLOC_ERROR, "%s", whence);
348 }
349
350 // Grow a new Chunk
351 void* Arena::grow(size_t x, AllocFailType alloc_failmode) {
352 // Get minimal required size. Either real big, or even bigger for giant objs
353 size_t len = MAX2(x, (size_t) Chunk::size);
354
355 Chunk *k = _chunk; // Get filled-up chunk address
356 _chunk = new (alloc_failmode, len) Chunk(len);
357
358 if (_chunk == NULL) {
359 _chunk = k; // restore the previous value of _chunk
360 return NULL;
361 }
362 if (k) k->set_next(_chunk); // Append new chunk to end of linked list
363 else _first = _chunk;
364 _hwm = _chunk->bottom(); // Save the cached hwm, max
365 _max = _chunk->top();
366 set_size_in_bytes(size_in_bytes() + len);
367 void* result = _hwm;
368 _hwm += x;
369 return result;
370 }
371
372
373
374 // Reallocate storage in Arena.
375 void *Arena::Arealloc(void* old_ptr, size_t old_size, size_t new_size, AllocFailType alloc_failmode) {
376 if (new_size == 0) return NULL;
377 #ifdef ASSERT
378 if (UseMallocOnly) {
379 // always allocate a new object (otherwise we'll free this one twice)
380 char* copy = (char*)Amalloc(new_size, alloc_failmode);
381 if (copy == NULL) {
382 return NULL;
383 }
384 size_t n = MIN2(old_size, new_size);
385 if (n > 0) memcpy(copy, old_ptr, n);
386 Afree(old_ptr,old_size); // Mostly done to keep stats accurate
387 return copy;
388 }
389 #endif
390 char *c_old = (char*)old_ptr; // Handy name
391 // Stupid fast special case
392 if( new_size <= old_size ) { // Shrink in-place
393 if( c_old+old_size == _hwm) // Attempt to free the excess bytes
394 _hwm = c_old+new_size; // Adjust hwm
395 return c_old;
396 }
397
398 // make sure that new_size is legal
399 size_t corrected_new_size = ARENA_ALIGN(new_size);
400
401 // See if we can resize in-place
402 if( (c_old+old_size == _hwm) && // Adjusting recent thing
403 (c_old+corrected_new_size <= _max) ) { // Still fits where it sits
404 _hwm = c_old+corrected_new_size; // Adjust hwm
405 return c_old; // Return old pointer
406 }
407
408 // Oops, got to relocate guts
409 void *new_ptr = Amalloc(new_size, alloc_failmode);
410 if (new_ptr == NULL) {
411 return NULL;
412 }
413 memcpy( new_ptr, c_old, old_size );
414 Afree(c_old,old_size); // Mostly done to keep stats accurate
415 return new_ptr;
416 }
417
418
419 // Determine if pointer belongs to this Arena or not.
420 bool Arena::contains( const void *ptr ) const {
421 #ifdef ASSERT
422 if (UseMallocOnly) {
423 // really slow, but not easy to make fast
424 if (_chunk == NULL) return false;
425 char** bottom = (char**)_chunk->bottom();
426 for (char** p = (char**)_hwm - 1; p >= bottom; p--) {
427 if (*p == ptr) return true;
428 }
429 for (Chunk *c = _first; c != NULL; c = c->next()) {
430 if (c == _chunk) continue; // current chunk has been processed
431 char** bottom = (char**)c->bottom();
432 for (char** p = (char**)c->top() - 1; p >= bottom; p--) {
433 if (*p == ptr) return true;
434 }
435 }
436 return false;
437 }
438 #endif
439 if( (void*)_chunk->bottom() <= ptr && ptr < (void*)_hwm )
440 return true; // Check for in this chunk
441 for (Chunk *c = _first; c; c = c->next()) {
442 if (c == _chunk) continue; // current chunk has been processed
443 if ((void*)c->bottom() <= ptr && ptr < (void*)c->top()) {
444 return true; // Check for every chunk in Arena
445 }
446 }
447 return false; // Not in any Chunk, so not in Arena
448 }
449
450
451 #ifdef ASSERT
452 void* Arena::malloc(size_t size) {
453 assert(UseMallocOnly, "shouldn't call");
454 // use malloc, but save pointer in res. area for later freeing
455 char** save = (char**)internal_malloc_4(sizeof(char*));
456 return (*save = (char*)os::malloc(size, mtChunk));
457 }
458
459 // for debugging with UseMallocOnly
460 void* Arena::internal_malloc_4(size_t x) {
461 assert( (x&(sizeof(char*)-1)) == 0, "misaligned size" );
462 check_for_overflow(x, "Arena::internal_malloc_4");
463 if (_hwm + x > _max) {
464 return grow(x);
465 } else {
466 char *old = _hwm;
467 _hwm += x;
468 return old;
469 }
470 }
471 #endif
472
473
474 //--------------------------------------------------------------------------------------
475 // Non-product code
476
477 #ifndef PRODUCT
478
479 julong Arena::_bytes_allocated = 0;
480
481 void Arena::inc_bytes_allocated(size_t x) { inc_stat_counter(&_bytes_allocated, x); }
482
483 // debugging code
484 inline void Arena::free_all(char** start, char** end) {
485 for (char** p = start; p < end; p++) if (*p) os::free(*p);
486 }
487
488 void Arena::free_malloced_objects(Chunk* chunk, char* hwm, char* max, char* hwm2) {
489 assert(UseMallocOnly, "should not call");
490 // free all objects malloced since resource mark was created; resource area
491 // contains their addresses
492 if (chunk->next()) {
493 // this chunk is full, and some others too
494 for (Chunk* c = chunk->next(); c != NULL; c = c->next()) {
495 char* top = c->top();
496 if (c->next() == NULL) {
497 top = hwm2; // last junk is only used up to hwm2
498 assert(c->contains(hwm2), "bad hwm2");
499 }
500 free_all((char**)c->bottom(), (char**)top);
501 }
502 assert(chunk->contains(hwm), "bad hwm");
503 assert(chunk->contains(max), "bad max");
504 free_all((char**)hwm, (char**)max);
505 } else {
506 // this chunk was partially used
507 assert(chunk->contains(hwm), "bad hwm");
508 assert(chunk->contains(hwm2), "bad hwm2");
509 free_all((char**)hwm, (char**)hwm2);
510 }
511 }
512
513 #endif // Non-product