Tue, 24 Dec 2013 11:48:39 -0800
8029233: Update copyright year to match last edit in jdk8 hotspot repository for 2013
Summary: Copyright year updated for files modified during 2013
Reviewed-by: twisti, iveresov
1 /*
2 * Copyright (c) 1997, 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 */
25 #include "precompiled.hpp"
26 #include "interpreter/oopMapCache.hpp"
27 #include "memory/allocation.inline.hpp"
28 #include "memory/resourceArea.hpp"
29 #include "oops/oop.inline.hpp"
30 #include "prims/jvmtiRedefineClassesTrace.hpp"
31 #include "runtime/handles.inline.hpp"
32 #include "runtime/signature.hpp"
34 class OopMapCacheEntry: private InterpreterOopMap {
35 friend class InterpreterOopMap;
36 friend class OopMapForCacheEntry;
37 friend class OopMapCache;
38 friend class VerifyClosure;
40 protected:
41 // Initialization
42 void fill(methodHandle method, int bci);
43 // fills the bit mask for native calls
44 void fill_for_native(methodHandle method);
45 void set_mask(CellTypeState* vars, CellTypeState* stack, int stack_top);
47 // Deallocate bit masks and initialize fields
48 void flush();
50 private:
51 void allocate_bit_mask(); // allocates the bit mask on C heap f necessary
52 void deallocate_bit_mask(); // allocates the bit mask on C heap f necessary
53 bool verify_mask(CellTypeState *vars, CellTypeState *stack, int max_locals, int stack_top);
55 public:
56 OopMapCacheEntry() : InterpreterOopMap() {
57 #ifdef ASSERT
58 _resource_allocate_bit_mask = false;
59 #endif
60 }
61 };
64 // Implementation of OopMapForCacheEntry
65 // (subclass of GenerateOopMap, initializes an OopMapCacheEntry for a given method and bci)
67 class OopMapForCacheEntry: public GenerateOopMap {
68 OopMapCacheEntry *_entry;
69 int _bci;
70 int _stack_top;
72 virtual bool report_results() const { return false; }
73 virtual bool possible_gc_point (BytecodeStream *bcs);
74 virtual void fill_stackmap_prolog (int nof_gc_points);
75 virtual void fill_stackmap_epilog ();
76 virtual void fill_stackmap_for_opcodes (BytecodeStream *bcs,
77 CellTypeState* vars,
78 CellTypeState* stack,
79 int stack_top);
80 virtual void fill_init_vars (GrowableArray<intptr_t> *init_vars);
82 public:
83 OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry *entry);
85 // Computes stack map for (method,bci) and initialize entry
86 void compute_map(TRAPS);
87 int size();
88 };
91 OopMapForCacheEntry::OopMapForCacheEntry(methodHandle method, int bci, OopMapCacheEntry* entry) : GenerateOopMap(method) {
92 _bci = bci;
93 _entry = entry;
94 _stack_top = -1;
95 }
98 void OopMapForCacheEntry::compute_map(TRAPS) {
99 assert(!method()->is_native(), "cannot compute oop map for native methods");
100 // First check if it is a method where the stackmap is always empty
101 if (method()->code_size() == 0 || method()->max_locals() + method()->max_stack() == 0) {
102 _entry->set_mask_size(0);
103 } else {
104 ResourceMark rm;
105 GenerateOopMap::compute_map(CATCH);
106 result_for_basicblock(_bci);
107 }
108 }
111 bool OopMapForCacheEntry::possible_gc_point(BytecodeStream *bcs) {
112 return false; // We are not reporting any result. We call result_for_basicblock directly
113 }
116 void OopMapForCacheEntry::fill_stackmap_prolog(int nof_gc_points) {
117 // Do nothing
118 }
121 void OopMapForCacheEntry::fill_stackmap_epilog() {
122 // Do nothing
123 }
126 void OopMapForCacheEntry::fill_init_vars(GrowableArray<intptr_t> *init_vars) {
127 // Do nothing
128 }
131 void OopMapForCacheEntry::fill_stackmap_for_opcodes(BytecodeStream *bcs,
132 CellTypeState* vars,
133 CellTypeState* stack,
134 int stack_top) {
135 // Only interested in one specific bci
136 if (bcs->bci() == _bci) {
137 _entry->set_mask(vars, stack, stack_top);
138 _stack_top = stack_top;
139 }
140 }
143 int OopMapForCacheEntry::size() {
144 assert(_stack_top != -1, "compute_map must be called first");
145 return ((method()->is_static()) ? 0 : 1) + method()->max_locals() + _stack_top;
146 }
149 // Implementation of InterpreterOopMap and OopMapCacheEntry
151 class VerifyClosure : public OffsetClosure {
152 private:
153 OopMapCacheEntry* _entry;
154 bool _failed;
156 public:
157 VerifyClosure(OopMapCacheEntry* entry) { _entry = entry; _failed = false; }
158 void offset_do(int offset) { if (!_entry->is_oop(offset)) _failed = true; }
159 bool failed() const { return _failed; }
160 };
162 InterpreterOopMap::InterpreterOopMap() {
163 initialize();
164 #ifdef ASSERT
165 _resource_allocate_bit_mask = true;
166 #endif
167 }
169 InterpreterOopMap::~InterpreterOopMap() {
170 // The expection is that the bit mask was allocated
171 // last in this resource area. That would make the free of the
172 // bit_mask effective (see how FREE_RESOURCE_ARRAY does a free).
173 // If it was not allocated last, there is not a correctness problem
174 // but the space for the bit_mask is not freed.
175 assert(_resource_allocate_bit_mask, "Trying to free C heap space");
176 if (mask_size() > small_mask_limit) {
177 FREE_RESOURCE_ARRAY(uintptr_t, _bit_mask[0], mask_word_size());
178 }
179 }
181 bool InterpreterOopMap::is_empty() {
182 bool result = _method == NULL;
183 assert(_method != NULL || (_bci == 0 &&
184 (_mask_size == 0 || _mask_size == USHRT_MAX) &&
185 _bit_mask[0] == 0), "Should be completely empty");
186 return result;
187 }
189 void InterpreterOopMap::initialize() {
190 _method = NULL;
191 _mask_size = USHRT_MAX; // This value should cause a failure quickly
192 _bci = 0;
193 _expression_stack_size = 0;
194 for (int i = 0; i < N; i++) _bit_mask[i] = 0;
195 }
197 void InterpreterOopMap::iterate_oop(OffsetClosure* oop_closure) {
198 int n = number_of_entries();
199 int word_index = 0;
200 uintptr_t value = 0;
201 uintptr_t mask = 0;
202 // iterate over entries
203 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
204 // get current word
205 if (mask == 0) {
206 value = bit_mask()[word_index++];
207 mask = 1;
208 }
209 // test for oop
210 if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i);
211 }
212 }
215 #ifdef ENABLE_ZAP_DEAD_LOCALS
217 void InterpreterOopMap::iterate_all(OffsetClosure* oop_closure, OffsetClosure* value_closure, OffsetClosure* dead_closure) {
218 int n = number_of_entries();
219 int word_index = 0;
220 uintptr_t value = 0;
221 uintptr_t mask = 0;
222 // iterate over entries
223 for (int i = 0; i < n; i++, mask <<= bits_per_entry) {
224 // get current word
225 if (mask == 0) {
226 value = bit_mask()[word_index++];
227 mask = 1;
228 }
229 // test for dead values & oops, and for live values
230 if ((value & (mask << dead_bit_number)) != 0) dead_closure->offset_do(i); // call this for all dead values or oops
231 else if ((value & (mask << oop_bit_number)) != 0) oop_closure->offset_do(i); // call this for all live oops
232 else value_closure->offset_do(i); // call this for all live values
233 }
234 }
236 #endif
239 void InterpreterOopMap::print() {
240 int n = number_of_entries();
241 tty->print("oop map for ");
242 method()->print_value();
243 tty->print(" @ %d = [%d] { ", bci(), n);
244 for (int i = 0; i < n; i++) {
245 #ifdef ENABLE_ZAP_DEAD_LOCALS
246 if (is_dead(i)) tty->print("%d+ ", i);
247 else
248 #endif
249 if (is_oop(i)) tty->print("%d ", i);
250 }
251 tty->print_cr("}");
252 }
254 class MaskFillerForNative: public NativeSignatureIterator {
255 private:
256 uintptr_t * _mask; // the bit mask to be filled
257 int _size; // the mask size in bits
259 void set_one(int i) {
260 i *= InterpreterOopMap::bits_per_entry;
261 assert(0 <= i && i < _size, "offset out of bounds");
262 _mask[i / BitsPerWord] |= (((uintptr_t) 1 << InterpreterOopMap::oop_bit_number) << (i % BitsPerWord));
263 }
265 public:
266 void pass_int() { /* ignore */ }
267 void pass_long() { /* ignore */ }
268 void pass_float() { /* ignore */ }
269 void pass_double() { /* ignore */ }
270 void pass_object() { set_one(offset()); }
272 MaskFillerForNative(methodHandle method, uintptr_t* mask, int size) : NativeSignatureIterator(method) {
273 _mask = mask;
274 _size = size;
275 // initialize with 0
276 int i = (size + BitsPerWord - 1) / BitsPerWord;
277 while (i-- > 0) _mask[i] = 0;
278 }
280 void generate() {
281 NativeSignatureIterator::iterate();
282 }
283 };
285 bool OopMapCacheEntry::verify_mask(CellTypeState* vars, CellTypeState* stack, int max_locals, int stack_top) {
286 // Check mask includes map
287 VerifyClosure blk(this);
288 iterate_oop(&blk);
289 if (blk.failed()) return false;
291 // Check if map is generated correctly
292 // (Use ?: operator to make sure all 'true' & 'false' are represented exactly the same so we can use == afterwards)
293 if (TraceOopMapGeneration && Verbose) tty->print("Locals (%d): ", max_locals);
295 for(int i = 0; i < max_locals; i++) {
296 bool v1 = is_oop(i) ? true : false;
297 bool v2 = vars[i].is_reference() ? true : false;
298 assert(v1 == v2, "locals oop mask generation error");
299 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
300 #ifdef ENABLE_ZAP_DEAD_LOCALS
301 bool v3 = is_dead(i) ? true : false;
302 bool v4 = !vars[i].is_live() ? true : false;
303 assert(v3 == v4, "locals live mask generation error");
304 assert(!(v1 && v3), "dead value marked as oop");
305 #endif
306 }
308 if (TraceOopMapGeneration && Verbose) { tty->cr(); tty->print("Stack (%d): ", stack_top); }
309 for(int j = 0; j < stack_top; j++) {
310 bool v1 = is_oop(max_locals + j) ? true : false;
311 bool v2 = stack[j].is_reference() ? true : false;
312 assert(v1 == v2, "stack oop mask generation error");
313 if (TraceOopMapGeneration && Verbose) tty->print("%d", v1 ? 1 : 0);
314 #ifdef ENABLE_ZAP_DEAD_LOCALS
315 bool v3 = is_dead(max_locals + j) ? true : false;
316 bool v4 = !stack[j].is_live() ? true : false;
317 assert(v3 == v4, "stack live mask generation error");
318 assert(!(v1 && v3), "dead value marked as oop");
319 #endif
320 }
321 if (TraceOopMapGeneration && Verbose) tty->cr();
322 return true;
323 }
325 void OopMapCacheEntry::allocate_bit_mask() {
326 if (mask_size() > small_mask_limit) {
327 assert(_bit_mask[0] == 0, "bit mask should be new or just flushed");
328 _bit_mask[0] = (intptr_t)
329 NEW_C_HEAP_ARRAY(uintptr_t, mask_word_size(), mtClass);
330 }
331 }
333 void OopMapCacheEntry::deallocate_bit_mask() {
334 if (mask_size() > small_mask_limit && _bit_mask[0] != 0) {
335 assert(!Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
336 "This bit mask should not be in the resource area");
337 FREE_C_HEAP_ARRAY(uintptr_t, _bit_mask[0], mtClass);
338 debug_only(_bit_mask[0] = 0;)
339 }
340 }
343 void OopMapCacheEntry::fill_for_native(methodHandle mh) {
344 assert(mh->is_native(), "method must be native method");
345 set_mask_size(mh->size_of_parameters() * bits_per_entry);
346 allocate_bit_mask();
347 // fill mask for parameters
348 MaskFillerForNative mf(mh, bit_mask(), mask_size());
349 mf.generate();
350 }
353 void OopMapCacheEntry::fill(methodHandle method, int bci) {
354 HandleMark hm;
355 // Flush entry to deallocate an existing entry
356 flush();
357 set_method(method());
358 set_bci(bci);
359 if (method->is_native()) {
360 // Native method activations have oops only among the parameters and one
361 // extra oop following the parameters (the mirror for static native methods).
362 fill_for_native(method);
363 } else {
364 EXCEPTION_MARK;
365 OopMapForCacheEntry gen(method, bci, this);
366 gen.compute_map(CATCH);
367 }
368 }
371 void OopMapCacheEntry::set_mask(CellTypeState *vars, CellTypeState *stack, int stack_top) {
372 // compute bit mask size
373 int max_locals = method()->max_locals();
374 int n_entries = max_locals + stack_top;
375 set_mask_size(n_entries * bits_per_entry);
376 allocate_bit_mask();
377 set_expression_stack_size(stack_top);
379 // compute bits
380 int word_index = 0;
381 uintptr_t value = 0;
382 uintptr_t mask = 1;
384 CellTypeState* cell = vars;
385 for (int entry_index = 0; entry_index < n_entries; entry_index++, mask <<= bits_per_entry, cell++) {
386 // store last word
387 if (mask == 0) {
388 bit_mask()[word_index++] = value;
389 value = 0;
390 mask = 1;
391 }
393 // switch to stack when done with locals
394 if (entry_index == max_locals) {
395 cell = stack;
396 }
398 // set oop bit
399 if ( cell->is_reference()) {
400 value |= (mask << oop_bit_number );
401 }
403 #ifdef ENABLE_ZAP_DEAD_LOCALS
404 // set dead bit
405 if (!cell->is_live()) {
406 value |= (mask << dead_bit_number);
407 assert(!cell->is_reference(), "dead value marked as oop");
408 }
409 #endif
410 }
412 // make sure last word is stored
413 bit_mask()[word_index] = value;
415 // verify bit mask
416 assert(verify_mask(vars, stack, max_locals, stack_top), "mask could not be verified");
419 }
421 void OopMapCacheEntry::flush() {
422 deallocate_bit_mask();
423 initialize();
424 }
427 // Implementation of OopMapCache
429 #ifndef PRODUCT
431 static long _total_memory_usage = 0;
433 long OopMapCache::memory_usage() {
434 return _total_memory_usage;
435 }
437 #endif
439 void InterpreterOopMap::resource_copy(OopMapCacheEntry* from) {
440 assert(_resource_allocate_bit_mask,
441 "Should not resource allocate the _bit_mask");
443 set_method(from->method());
444 set_bci(from->bci());
445 set_mask_size(from->mask_size());
446 set_expression_stack_size(from->expression_stack_size());
448 // Is the bit mask contained in the entry?
449 if (from->mask_size() <= small_mask_limit) {
450 memcpy((void *)_bit_mask, (void *)from->_bit_mask,
451 mask_word_size() * BytesPerWord);
452 } else {
453 // The expectation is that this InterpreterOopMap is a recently created
454 // and empty. It is used to get a copy of a cached entry.
455 // If the bit mask has a value, it should be in the
456 // resource area.
457 assert(_bit_mask[0] == 0 ||
458 Thread::current()->resource_area()->contains((void*)_bit_mask[0]),
459 "The bit mask should have been allocated from a resource area");
460 // Allocate the bit_mask from a Resource area for performance. Allocating
461 // from the C heap as is done for OopMapCache has a significant
462 // performance impact.
463 _bit_mask[0] = (uintptr_t) NEW_RESOURCE_ARRAY(uintptr_t, mask_word_size());
464 assert(_bit_mask[0] != 0, "bit mask was not allocated");
465 memcpy((void*) _bit_mask[0], (void*) from->_bit_mask[0],
466 mask_word_size() * BytesPerWord);
467 }
468 }
470 inline unsigned int OopMapCache::hash_value_for(methodHandle method, int bci) {
471 // We use method->code_size() rather than method->identity_hash() below since
472 // the mark may not be present if a pointer to the method is already reversed.
473 return ((unsigned int) bci)
474 ^ ((unsigned int) method->max_locals() << 2)
475 ^ ((unsigned int) method->code_size() << 4)
476 ^ ((unsigned int) method->size_of_parameters() << 6);
477 }
480 OopMapCache::OopMapCache() :
481 _mut(Mutex::leaf, "An OopMapCache lock", true)
482 {
483 _array = NEW_C_HEAP_ARRAY(OopMapCacheEntry, _size, mtClass);
484 // Cannot call flush for initialization, since flush
485 // will check if memory should be deallocated
486 for(int i = 0; i < _size; i++) _array[i].initialize();
487 NOT_PRODUCT(_total_memory_usage += sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
488 }
491 OopMapCache::~OopMapCache() {
492 assert(_array != NULL, "sanity check");
493 // Deallocate oop maps that are allocated out-of-line
494 flush();
495 // Deallocate array
496 NOT_PRODUCT(_total_memory_usage -= sizeof(OopMapCache) + (sizeof(OopMapCacheEntry) * _size);)
497 FREE_C_HEAP_ARRAY(OopMapCacheEntry, _array, mtClass);
498 }
500 OopMapCacheEntry* OopMapCache::entry_at(int i) const {
501 return &_array[i % _size];
502 }
504 void OopMapCache::flush() {
505 for (int i = 0; i < _size; i++) _array[i].flush();
506 }
508 void OopMapCache::flush_obsolete_entries() {
509 for (int i = 0; i < _size; i++)
510 if (!_array[i].is_empty() && _array[i].method()->is_old()) {
511 // Cache entry is occupied by an old redefined method and we don't want
512 // to pin it down so flush the entry.
513 RC_TRACE(0x08000000, ("flush: %s(%s): cached entry @%d",
514 _array[i].method()->name()->as_C_string(),
515 _array[i].method()->signature()->as_C_string(), i));
517 _array[i].flush();
518 }
519 }
521 void OopMapCache::lookup(methodHandle method,
522 int bci,
523 InterpreterOopMap* entry_for) {
524 MutexLocker x(&_mut);
526 OopMapCacheEntry* entry = NULL;
527 int probe = hash_value_for(method, bci);
529 // Search hashtable for match
530 int i;
531 for(i = 0; i < _probe_depth; i++) {
532 entry = entry_at(probe + i);
533 if (entry->match(method, bci)) {
534 entry_for->resource_copy(entry);
535 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
536 return;
537 }
538 }
540 if (TraceOopMapGeneration) {
541 static int count = 0;
542 ResourceMark rm;
543 tty->print("%d - Computing oopmap at bci %d for ", ++count, bci);
544 method->print_value(); tty->cr();
545 }
547 // Entry is not in hashtable.
548 // Compute entry and return it
550 if (method->should_not_be_cached()) {
551 // It is either not safe or not a good idea to cache this Method*
552 // at this time. We give the caller of lookup() a copy of the
553 // interesting info via parameter entry_for, but we don't add it to
554 // the cache. See the gory details in Method*.cpp.
555 compute_one_oop_map(method, bci, entry_for);
556 return;
557 }
559 // First search for an empty slot
560 for(i = 0; i < _probe_depth; i++) {
561 entry = entry_at(probe + i);
562 if (entry->is_empty()) {
563 entry->fill(method, bci);
564 entry_for->resource_copy(entry);
565 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
566 return;
567 }
568 }
570 if (TraceOopMapGeneration) {
571 ResourceMark rm;
572 tty->print_cr("*** collision in oopmap cache - flushing item ***");
573 }
575 // No empty slot (uncommon case). Use (some approximation of a) LRU algorithm
576 //entry_at(probe + _probe_depth - 1)->flush();
577 //for(i = _probe_depth - 1; i > 0; i--) {
578 // // Coping entry[i] = entry[i-1];
579 // OopMapCacheEntry *to = entry_at(probe + i);
580 // OopMapCacheEntry *from = entry_at(probe + i - 1);
581 // to->copy(from);
582 // }
584 assert(method->is_method(), "gaga");
586 entry = entry_at(probe + 0);
587 entry->fill(method, bci);
589 // Copy the newly cached entry to input parameter
590 entry_for->resource_copy(entry);
592 if (TraceOopMapGeneration) {
593 ResourceMark rm;
594 tty->print("Done with ");
595 method->print_value(); tty->cr();
596 }
597 assert(!entry_for->is_empty(), "A non-empty oop map should be returned");
599 return;
600 }
602 void OopMapCache::compute_one_oop_map(methodHandle method, int bci, InterpreterOopMap* entry) {
603 // Due to the invariants above it's tricky to allocate a temporary OopMapCacheEntry on the stack
604 OopMapCacheEntry* tmp = NEW_C_HEAP_ARRAY(OopMapCacheEntry, 1, mtClass);
605 tmp->initialize();
606 tmp->fill(method, bci);
607 entry->resource_copy(tmp);
608 FREE_C_HEAP_ARRAY(OopMapCacheEntry, tmp, mtInternal);
609 }