1 /*
2 * Copyright (c) 1997, 2026, 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 "classfile/javaClasses.inline.hpp"
26 #include "classfile/symbolTable.hpp"
27 #include "classfile/systemDictionary.hpp"
28 #include "classfile/vmClasses.hpp"
29 #include "code/codeCache.hpp"
30 #include "code/debugInfoRec.hpp"
31 #include "code/nmethod.hpp"
32 #include "code/pcDesc.hpp"
33 #include "code/scopeDesc.hpp"
34 #include "compiler/compilationPolicy.hpp"
35 #include "compiler/compilerDefinitions.inline.hpp"
36 #include "gc/shared/collectedHeap.hpp"
37 #include "gc/shared/memAllocator.hpp"
38 #include "interpreter/bytecode.inline.hpp"
39 #include "interpreter/bytecodeStream.hpp"
40 #include "interpreter/interpreter.hpp"
41 #include "interpreter/oopMapCache.hpp"
42 #include "jvm.h"
43 #include "logging/log.hpp"
44 #include "logging/logLevel.hpp"
45 #include "logging/logMessage.hpp"
46 #include "logging/logStream.hpp"
47 #include "memory/allocation.inline.hpp"
48 #include "memory/oopFactory.hpp"
49 #include "memory/resourceArea.hpp"
50 #include "memory/universe.hpp"
51 #include "oops/arrayOop.inline.hpp"
52 #include "oops/constantPool.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/flatArrayKlass.hpp"
55 #include "oops/flatArrayOop.hpp"
56 #include "oops/inlineKlass.inline.hpp"
57 #include "oops/method.hpp"
58 #include "oops/objArrayKlass.hpp"
59 #include "oops/objArrayOop.inline.hpp"
60 #include "oops/oop.inline.hpp"
61 #include "oops/typeArrayOop.inline.hpp"
62 #include "oops/verifyOopClosure.hpp"
63 #include "prims/jvmtiDeferredUpdates.hpp"
64 #include "prims/jvmtiExport.hpp"
65 #include "prims/jvmtiThreadState.hpp"
66 #include "prims/methodHandles.hpp"
67 #include "prims/vectorSupport.hpp"
68 #include "runtime/arguments.hpp"
69 #include "runtime/atomicAccess.hpp"
70 #include "runtime/basicLock.inline.hpp"
71 #include "runtime/continuation.hpp"
72 #include "runtime/continuationEntry.inline.hpp"
73 #include "runtime/deoptimization.hpp"
74 #include "runtime/escapeBarrier.hpp"
75 #include "runtime/fieldDescriptor.inline.hpp"
76 #include "runtime/frame.inline.hpp"
77 #include "runtime/handles.inline.hpp"
78 #include "runtime/interfaceSupport.inline.hpp"
79 #include "runtime/javaThread.hpp"
80 #include "runtime/jniHandles.inline.hpp"
81 #include "runtime/keepStackGCProcessed.hpp"
82 #include "runtime/lockStack.inline.hpp"
83 #include "runtime/objectMonitor.inline.hpp"
84 #include "runtime/osThread.hpp"
85 #include "runtime/safepointVerifiers.hpp"
86 #include "runtime/sharedRuntime.hpp"
87 #include "runtime/signature.hpp"
88 #include "runtime/stackFrameStream.inline.hpp"
89 #include "runtime/stackValue.hpp"
90 #include "runtime/stackWatermarkSet.hpp"
91 #include "runtime/stubRoutines.hpp"
92 #include "runtime/synchronizer.hpp"
93 #include "runtime/threadSMR.hpp"
94 #include "runtime/threadWXSetters.inline.hpp"
95 #include "runtime/vframe.hpp"
96 #include "runtime/vframe_hp.hpp"
97 #include "runtime/vframeArray.hpp"
98 #include "runtime/vmOperations.hpp"
99 #include "utilities/checkedCast.hpp"
100 #include "utilities/events.hpp"
101 #include "utilities/growableArray.hpp"
102 #include "utilities/macros.hpp"
103 #include "utilities/preserveException.hpp"
104 #include "utilities/xmlstream.hpp"
105 #if INCLUDE_JFR
106 #include "jfr/jfr.inline.hpp"
107 #include "jfr/jfrEvents.hpp"
108 #include "jfr/metadata/jfrSerializer.hpp"
109 #endif
110
111 uint64_t DeoptimizationScope::_committed_deopt_gen = 0;
112 uint64_t DeoptimizationScope::_active_deopt_gen = 1;
113 bool DeoptimizationScope::_committing_in_progress = false;
114
115 DeoptimizationScope::DeoptimizationScope() : _required_gen(0) {
116 DEBUG_ONLY(_deopted = false;)
117
118 MutexLocker ml(NMethodState_lock, Mutex::_no_safepoint_check_flag);
119 // If there is nothing to deopt _required_gen is the same as comitted.
120 _required_gen = DeoptimizationScope::_committed_deopt_gen;
121 }
122
123 DeoptimizationScope::~DeoptimizationScope() {
124 assert(_deopted, "Deopt not executed");
125 }
126
127 void DeoptimizationScope::mark(nmethod* nm, bool inc_recompile_counts) {
128 if (!nm->can_be_deoptimized()) {
129 return;
130 }
131
132 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
133
134 // If it's already marked but we still need it to be deopted.
135 if (nm->is_marked_for_deoptimization()) {
136 dependent(nm);
137 return;
138 }
139
140 MACOS_AARCH64_ONLY(os::thread_wx_enable_write());
141 nmethod::DeoptimizationStatus status =
142 inc_recompile_counts ? nmethod::deoptimize : nmethod::deoptimize_noupdate;
143 AtomicAccess::store(&nm->_deoptimization_status, status);
144
145 // Make sure active is not committed
146 assert(DeoptimizationScope::_committed_deopt_gen < DeoptimizationScope::_active_deopt_gen, "Must be");
147 assert(nm->_deoptimization_generation == 0, "Is already marked");
148
149 nm->_deoptimization_generation = DeoptimizationScope::_active_deopt_gen;
150 _required_gen = DeoptimizationScope::_active_deopt_gen;
151 }
152
153 void DeoptimizationScope::dependent(nmethod* nm) {
154 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
155
156 // A method marked by someone else may have a _required_gen lower than what we marked with.
157 // Therefore only store it if it's higher than _required_gen.
158 if (_required_gen < nm->_deoptimization_generation) {
159 _required_gen = nm->_deoptimization_generation;
160 }
161 }
162
163 void DeoptimizationScope::deoptimize_marked() {
164 assert(!_deopted, "Already deopted");
165
166 // We are not alive yet.
167 if (!Universe::is_fully_initialized()) {
168 DEBUG_ONLY(_deopted = true;)
169 return;
170 }
171
172 // Safepoints are a special case, handled here.
173 if (SafepointSynchronize::is_at_safepoint()) {
174 DeoptimizationScope::_committed_deopt_gen = DeoptimizationScope::_active_deopt_gen;
175 DeoptimizationScope::_active_deopt_gen++;
176 Deoptimization::deoptimize_all_marked();
177 DEBUG_ONLY(_deopted = true;)
178 return;
179 }
180
181 uint64_t comitting = 0;
182 bool wait = false;
183 while (true) {
184 {
185 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
186
187 // First we check if we or someone else already deopted the gen we want.
188 if (DeoptimizationScope::_committed_deopt_gen >= _required_gen) {
189 DEBUG_ONLY(_deopted = true;)
190 return;
191 }
192 if (!_committing_in_progress) {
193 // The version we are about to commit.
194 comitting = DeoptimizationScope::_active_deopt_gen;
195 // Make sure new marks use a higher gen.
196 DeoptimizationScope::_active_deopt_gen++;
197 _committing_in_progress = true;
198 wait = false;
199 } else {
200 // Another thread is handshaking and committing a gen.
201 wait = true;
202 }
203 }
204 if (wait) {
205 // Wait and let the concurrent handshake be performed.
206 ThreadBlockInVM tbivm(JavaThread::current());
207 os::naked_yield();
208 } else {
209 // Performs the handshake.
210 Deoptimization::deoptimize_all_marked(); // May safepoint and an additional deopt may have occurred.
211 DEBUG_ONLY(_deopted = true;)
212 {
213 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
214
215 // Make sure that committed doesn't go backwards.
216 // Should only happen if we did a deopt during a safepoint above.
217 if (DeoptimizationScope::_committed_deopt_gen < comitting) {
218 DeoptimizationScope::_committed_deopt_gen = comitting;
219 }
220 _committing_in_progress = false;
221
222 assert(DeoptimizationScope::_committed_deopt_gen >= _required_gen, "Must be");
223
224 return;
225 }
226 }
227 }
228 }
229
230 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
231 int caller_adjustment,
232 int caller_actual_parameters,
233 int number_of_frames,
234 intptr_t* frame_sizes,
235 address* frame_pcs,
236 BasicType return_type,
237 int exec_mode) {
238 _size_of_deoptimized_frame = size_of_deoptimized_frame;
239 _caller_adjustment = caller_adjustment;
240 _caller_actual_parameters = caller_actual_parameters;
241 _number_of_frames = number_of_frames;
242 _frame_sizes = frame_sizes;
243 _frame_pcs = frame_pcs;
244 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
245 _return_type = return_type;
246 _initial_info = 0;
247 // PD (x86 only)
248 _counter_temp = 0;
249 _unpack_kind = exec_mode;
250 _sender_sp_temp = 0;
251
252 _total_frame_sizes = size_of_frames();
253 assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
254 }
255
256 Deoptimization::UnrollBlock::~UnrollBlock() {
257 FREE_C_HEAP_ARRAY(_frame_sizes);
258 FREE_C_HEAP_ARRAY(_frame_pcs);
259 FREE_C_HEAP_ARRAY(_register_block);
260 }
261
262 int Deoptimization::UnrollBlock::size_of_frames() const {
263 // Account first for the adjustment of the initial frame
264 intptr_t result = _caller_adjustment;
265 for (int index = 0; index < number_of_frames(); index++) {
266 result += frame_sizes()[index];
267 }
268 return checked_cast<int>(result);
269 }
270
271 void Deoptimization::UnrollBlock::print() {
272 ResourceMark rm;
273 stringStream st;
274 st.print_cr("UnrollBlock");
275 st.print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
276 st.print( " frame_sizes: ");
277 for (int index = 0; index < number_of_frames(); index++) {
278 st.print("%zd ", frame_sizes()[index]);
279 }
280 st.cr();
281 tty->print_raw(st.freeze());
282 }
283
284 // In order to make fetch_unroll_info work properly with escape
285 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
286 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
287 // which is called from the method fetch_unroll_info_helper below.
288 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
289 // fetch_unroll_info() is called at the beginning of the deoptimization
290 // handler. Note this fact before we start generating temporary frames
291 // that can confuse an asynchronous stack walker. This counter is
292 // decremented at the end of unpack_frames().
293 current->inc_in_deopt_handler();
294
295 if (exec_mode == Unpack_exception) {
296 // When we get here, a callee has thrown an exception into a deoptimized
297 // frame. That throw might have deferred stack watermark checking until
298 // after unwinding. So we deal with such deferred requests here.
299 StackWatermarkSet::after_unwind(current);
300 }
301
302 return fetch_unroll_info_helper(current, exec_mode);
303 JRT_END
304
305 #ifdef COMPILER2
306
307 static Klass* get_refined_array_klass(Klass* k, frame* fr, RegisterMap* map, ObjectValue* sv, TRAPS) {
308 // If it's an array, get the properties
309 if (k->is_array_klass() && !k->is_typeArray_klass()) {
310 assert(k->is_unrefined_objArray_klass(), "Expected unrefined array klass");
311 nmethod* nm = fr->cb()->as_nmethod_or_null();
312 assert(sv->has_properties(), "Property information is missing");
313 ArrayProperties props(checked_cast<ArrayProperties::Type>(StackValue::create_stack_value(fr, map, sv->properties())->get_jint()));
314 k = ObjArrayKlass::cast(k)->klass_with_properties(props, THREAD);
315 }
316 return k;
317 }
318
319 // print information about reallocated objects
320 static void print_objects(JavaThread* deoptee_thread, frame* deoptee, RegisterMap* map,
321 GrowableArray<ScopeValue*>* objects, bool realloc_failures, TRAPS) {
322 ResourceMark rm;
323 stringStream st; // change to logStream with logging
324 st.print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
325 fieldDescriptor fd;
326
327 for (int i = 0; i < objects->length(); i++) {
328 ObjectValue* sv = (ObjectValue*) objects->at(i);
329 Handle obj = sv->value();
330
331 if (obj.is_null()) {
332 st.print_cr(" nullptr");
333 continue;
334 }
335
336 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
337 k = get_refined_array_klass(k, deoptee, map, sv, THREAD);
338
339 st.print(" object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
340 k->print_value_on(&st);
341 st.print_cr(" allocated (%zu bytes)", obj->size() * HeapWordSize);
342
343 if (Verbose && k != nullptr) {
344 k->oop_print_on(obj(), &st);
345 }
346 }
347 tty->print_raw(st.freeze());
348 }
349
350 static bool rematerialize_objects(JavaThread* thread, int exec_mode, nmethod* compiled_method,
351 frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
352 bool& deoptimized_objects) {
353 bool realloc_failures = false;
354 assert (chunk->at(0)->scope() != nullptr,"expect only compiled java frames");
355
356 JavaThread* deoptee_thread = chunk->at(0)->thread();
357 assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
358 "a frame can only be deoptimized by the owner thread");
359
360 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects_to_rematerialize(deoptee, map);
361
362 // The flag return_oop() indicates call sites which return oop
363 // in compiled code. Such sites include java method calls,
364 // runtime calls (for example, used to allocate new objects/arrays
365 // on slow code path) and any other calls generated in compiled code.
366 // It is not guaranteed that we can get such information here only
367 // by analyzing bytecode in deoptimized frames. This is why this flag
368 // is set during method compilation (see Compile::Process_OopMap_Node()).
369 // If the previous frame was popped or if we are dispatching an exception,
370 // we don't have an oop result.
371 ScopeDesc* scope = chunk->at(0)->scope();
372 bool save_oop_result = scope->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt);
373 // In case of the return of multiple values, we must take care
374 // of all oop return values.
375 GrowableArray<Handle> return_oops;
376 InlineKlass* vk = nullptr;
377 if (save_oop_result && scope->return_scalarized()) {
378 vk = InlineKlass::returned_inline_klass(map);
379 if (vk != nullptr) {
380 vk->save_oop_fields(map, return_oops);
381 save_oop_result = false;
382 }
383 }
384 if (save_oop_result) {
385 // Reallocation may trigger GC. If deoptimization happened on return from
386 // call which returns oop we need to save it since it is not in oopmap.
387 oop result = deoptee.saved_oop_result(&map);
388 assert(oopDesc::is_oop_or_null(result), "must be oop");
389 return_oops.push(Handle(thread, result));
390 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
391 if (TraceDeoptimization) {
392 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
393 tty->cr();
394 }
395 }
396 if (objects != nullptr || vk != nullptr) {
397 if (exec_mode == Deoptimization::Unpack_none) {
398 assert(thread->thread_state() == _thread_in_vm, "assumption");
399 JavaThread* THREAD = thread; // For exception macros.
400 // Clear pending OOM if reallocation fails and return true indicating allocation failure
401 if (vk != nullptr) {
402 realloc_failures = Deoptimization::realloc_inline_type_result(vk, map, return_oops, CHECK_AND_CLEAR_(true));
403 }
404 if (objects != nullptr) {
405 realloc_failures = realloc_failures || Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
406 guarantee(compiled_method != nullptr, "deopt must be associated with an nmethod");
407 Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, CHECK_AND_CLEAR_(true));
408 }
409 deoptimized_objects = true;
410 } else {
411 JavaThread* current = thread; // For JRT_BLOCK
412 JRT_BLOCK
413 if (vk != nullptr) {
414 realloc_failures = Deoptimization::realloc_inline_type_result(vk, map, return_oops, THREAD);
415 }
416 if (objects != nullptr) {
417 realloc_failures = realloc_failures || Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
418 guarantee(compiled_method != nullptr, "deopt must be associated with an nmethod");
419 Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, THREAD);
420 }
421 JRT_END
422 }
423 if (TraceDeoptimization && objects != nullptr) {
424 print_objects(deoptee_thread, &deoptee, &map, objects, realloc_failures, thread);
425 }
426 }
427 if (save_oop_result || vk != nullptr) {
428 // Restore result.
429 assert(return_oops.length() == 1, "no inline type");
430 deoptee.set_saved_oop_result(&map, return_oops.pop()());
431 }
432 return realloc_failures;
433 }
434
435 static void restore_eliminated_locks(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures,
436 frame& deoptee, int exec_mode, bool& deoptimized_objects) {
437 JavaThread* deoptee_thread = chunk->at(0)->thread();
438 assert(!EscapeBarrier::objs_are_deoptimized(deoptee_thread, deoptee.id()), "must relock just once");
439 assert(thread == Thread::current(), "should be");
440 HandleMark hm(thread);
441 #ifndef PRODUCT
442 bool first = true;
443 #endif // !PRODUCT
444 // Start locking from outermost/oldest frame
445 for (int i = (chunk->length() - 1); i >= 0; i--) {
446 compiledVFrame* cvf = chunk->at(i);
447 assert (cvf->scope() != nullptr,"expect only compiled java frames");
448 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
449 if (monitors->is_nonempty()) {
450 bool relocked = Deoptimization::relock_objects(thread, monitors, deoptee_thread, deoptee,
451 exec_mode, realloc_failures);
452 deoptimized_objects = deoptimized_objects || relocked;
453 #ifndef PRODUCT
454 if (PrintDeoptimizationDetails) {
455 ResourceMark rm;
456 stringStream st;
457 for (int j = 0; j < monitors->length(); j++) {
458 MonitorInfo* mi = monitors->at(j);
459 if (mi->eliminated()) {
460 if (first) {
461 first = false;
462 st.print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
463 }
464 if (exec_mode == Deoptimization::Unpack_none) {
465 ObjectMonitor* monitor = deoptee_thread->current_waiting_monitor();
466 if (monitor != nullptr && monitor->object() == mi->owner()) {
467 st.print_cr(" object <" INTPTR_FORMAT "> DEFERRED relocking after wait", p2i(mi->owner()));
468 continue;
469 }
470 }
471 if (mi->owner_is_scalar_replaced()) {
472 Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
473 st.print_cr(" failed reallocation for klass %s", k->external_name());
474 } else {
475 st.print_cr(" object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
476 }
477 }
478 }
479 tty->print_raw(st.freeze());
480 }
481 #endif // !PRODUCT
482 }
483 }
484 }
485
486 // Deoptimize objects, that is reallocate and relock them, just before they escape through JVMTI.
487 // The given vframes cover one physical frame.
488 bool Deoptimization::deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
489 bool& realloc_failures) {
490 frame deoptee = chunk->at(0)->fr();
491 JavaThread* deoptee_thread = chunk->at(0)->thread();
492 nmethod* nm = deoptee.cb()->as_nmethod_or_null();
493 RegisterMap map(chunk->at(0)->register_map());
494 bool deoptimized_objects = false;
495
496 // Reallocate the non-escaping objects and restore their fields.
497 if (((DoEscapeAnalysis || Arguments::is_valhalla_enabled()) && EliminateAllocations) ||
498 EliminateAutoBox || EnableVectorAggressiveReboxing) {
499 realloc_failures = rematerialize_objects(thread, Unpack_none, nm, deoptee, map, chunk, deoptimized_objects);
500 }
501
502 // MonitorInfo structures used in eliminate_locks are not GC safe.
503 NoSafepointVerifier no_safepoint;
504
505 // Now relock objects if synchronization on them was eliminated.
506 if ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) {
507 restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
508 }
509 return deoptimized_objects;
510 }
511 #endif // COMPILER2
512
513 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
514 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
515 JFR_ONLY(Jfr::check_and_process_sample_request(current);)
516 // When we get here we are about to unwind the deoptee frame. In order to
517 // catch not yet safe to use frames, the following stack watermark barrier
518 // poll will make such frames safe to use.
519 StackWatermarkSet::before_unwind(current);
520
521 // Note: there is a safepoint safety issue here. No matter whether we enter
522 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
523 // the vframeArray is created.
524 //
525
526 // Allocate our special deoptimization ResourceMark
527 DeoptResourceMark* dmark = new DeoptResourceMark(current);
528 assert(current->deopt_mark() == nullptr, "Pending deopt!");
529 current->set_deopt_mark(dmark);
530
531 frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
532 RegisterMap map(current,
533 RegisterMap::UpdateMap::include,
534 RegisterMap::ProcessFrames::include,
535 RegisterMap::WalkContinuation::skip);
536 RegisterMap dummy_map(current,
537 RegisterMap::UpdateMap::skip,
538 RegisterMap::ProcessFrames::include,
539 RegisterMap::WalkContinuation::skip);
540 // Now get the deoptee with a valid map
541 frame deoptee = stub_frame.sender(&map);
542 if (exec_mode == Unpack_deopt) {
543 assert(deoptee.is_deoptimized_frame(), "frame is not marked for deoptimization");
544 }
545 // Set the deoptee nmethod
546 assert(current->deopt_compiled_method() == nullptr, "Pending deopt!");
547 nmethod* nm = deoptee.cb()->as_nmethod_or_null();
548 current->set_deopt_compiled_method(nm);
549
550 if (VerifyStack) {
551 current->validate_frame_layout();
552 }
553
554 // Create a growable array of VFrames where each VFrame represents an inlined
555 // Java frame. This storage is allocated with the usual system arena.
556 assert(deoptee.is_compiled_frame(), "Wrong frame type");
557 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
558 vframe* vf = vframe::new_vframe(&deoptee, &map, current);
559 while (!vf->is_top()) {
560 assert(vf->is_compiled_frame(), "Wrong frame type");
561 chunk->push(compiledVFrame::cast(vf));
562 vf = vf->sender();
563 }
564 assert(vf->is_compiled_frame(), "Wrong frame type");
565 chunk->push(compiledVFrame::cast(vf));
566
567 bool realloc_failures = false;
568
569 #ifdef COMPILER2
570 // Reallocate the non-escaping objects and restore their fields. Then
571 // relock objects if synchronization on them was eliminated.
572 if (((DoEscapeAnalysis || Arguments::is_valhalla_enabled()) && EliminateAllocations) ||
573 EliminateAutoBox || EnableVectorAggressiveReboxing) {
574 bool unused;
575 realloc_failures = rematerialize_objects(current, exec_mode, nm, deoptee, map, chunk, unused);
576 }
577 #endif // COMPILER2
578
579 // Ensure that no safepoint is taken after pointers have been stored
580 // in fields of rematerialized objects. If a safepoint occurs from here on
581 // out the java state residing in the vframeArray will be missed.
582 // Locks may be rebaised in a safepoint.
583 NoSafepointVerifier no_safepoint;
584
585 #ifdef COMPILER2
586 if (((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) &&
587 !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
588 bool unused = false;
589 restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
590 }
591 #endif // COMPILER2
592
593 ScopeDesc* trap_scope = chunk->at(0)->scope();
594 Handle exceptionObject;
595 if (trap_scope->rethrow_exception()) {
596 #ifndef PRODUCT
597 if (PrintDeoptimizationDetails) {
598 tty->print_cr("Exception to be rethrown in the interpreter for method %s::%s at bci %d", trap_scope->method()->method_holder()->name()->as_C_string(), trap_scope->method()->name()->as_C_string(), trap_scope->bci());
599 }
600 #endif // !PRODUCT
601
602 GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
603 guarantee(expressions != nullptr && expressions->length() == 1, "should have only exception on stack");
604 guarantee(exec_mode != Unpack_exception, "rethrow_exception set with Unpack_exception");
605 ScopeValue* topOfStack = expressions->top();
606 exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
607 guarantee(exceptionObject() != nullptr, "exception oop can not be null");
608 }
609
610 vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
611 #ifdef COMPILER2
612 if (realloc_failures) {
613 // This destroys all ScopedValue bindings.
614 current->clear_scopedValueBindings();
615 pop_frames_failed_reallocs(current, array);
616 }
617 #endif // COMPILER2
618
619 assert(current->vframe_array_head() == nullptr, "Pending deopt!");
620 current->set_vframe_array_head(array);
621
622 // Now that the vframeArray has been created if we have any deferred local writes
623 // added by jvmti then we can free up that structure as the data is now in the
624 // vframeArray
625
626 JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
627
628 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
629 CodeBlob* cb = stub_frame.cb();
630 // Verify we have the right vframeArray
631 assert(cb->frame_size() >= 0, "Unexpected frame size");
632 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
633 assert(unpack_sp == deoptee.unextended_sp(), "must be");
634
635 #ifdef ASSERT
636 assert(cb->is_deoptimization_stub() ||
637 cb->is_uncommon_trap_stub() ||
638 strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
639 strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
640 "unexpected code blob: %s", cb->name());
641 #endif
642
643 // This is a guarantee instead of an assert because if vframe doesn't match
644 // we will unpack the wrong deoptimized frame and wind up in strange places
645 // where it will be very difficult to figure out what went wrong. Better
646 // to die an early death here than some very obscure death later when the
647 // trail is cold.
648 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
649
650 int number_of_frames = array->frames();
651
652 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
653 // virtual activation, which is the reverse of the elements in the vframes array.
654 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
655 // +1 because we always have an interpreter return address for the final slot.
656 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
657 int popframe_extra_args = 0;
658 // Create an interpreter return address for the stub to use as its return
659 // address so the skeletal frames are perfectly walkable
660 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
661
662 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
663 // activation be put back on the expression stack of the caller for reexecution
664 if (JvmtiExport::can_pop_frame() && current->popframe_forcing_deopt_reexecution()) {
665 popframe_extra_args = in_words(current->popframe_preserved_args_size_in_words());
666 }
667
668 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
669 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
670 // than simply use array->sender.pc(). This requires us to walk the current set of frames
671 //
672 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
673 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
674
675 // It's possible that the number of parameters at the call site is
676 // different than number of arguments in the callee when method
677 // handles are used. If the caller is interpreted get the real
678 // value so that the proper amount of space can be added to it's
679 // frame.
680 bool caller_was_method_handle = false;
681 if (deopt_sender.is_interpreted_frame()) {
682 methodHandle method(current, deopt_sender.interpreter_frame_method());
683 Bytecode_invoke cur(method, deopt_sender.interpreter_frame_bci());
684 if (cur.has_member_arg()) {
685 // This should cover all real-world cases. One exception is a pathological chain of
686 // MH.linkToXXX() linker calls, which only trusted code could do anyway. To handle that case, we
687 // would need to get the size from the resolved method entry. Another exception would
688 // be an invokedynamic with an adapter that is really a MethodHandle linker.
689 caller_was_method_handle = true;
690 }
691 }
692
693 //
694 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
695 // frame_sizes/frame_pcs[1] next oldest frame (int)
696 // frame_sizes/frame_pcs[n] youngest frame (int)
697 //
698 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
699 // owns the space for the return address to it's caller). Confusing ain't it.
700 //
701 // The vframe array can address vframes with indices running from
702 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
703 // When we create the skeletal frames we need the oldest frame to be in the zero slot
704 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
705 // so things look a little strange in this loop.
706 //
707 int callee_parameters = 0;
708 int callee_locals = 0;
709 for (int index = 0; index < array->frames(); index++ ) {
710 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
711 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
712 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
713 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
714 callee_locals,
715 index == 0,
716 popframe_extra_args);
717 // This pc doesn't have to be perfect just good enough to identify the frame
718 // as interpreted so the skeleton frame will be walkable
719 // The correct pc will be set when the skeleton frame is completely filled out
720 // The final pc we store in the loop is wrong and will be overwritten below
721 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
722
723 callee_parameters = array->element(index)->method()->size_of_parameters();
724 callee_locals = array->element(index)->method()->max_locals();
725 popframe_extra_args = 0;
726 }
727
728 // Compute whether the root vframe returns a float or double value.
729 BasicType return_type;
730 {
731 methodHandle method(current, array->element(0)->method());
732 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
733 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
734 }
735
736 // Compute information for handling adapters and adjusting the frame size of the caller.
737 int caller_adjustment = 0;
738
739 // Compute the amount the oldest interpreter frame will have to adjust
740 // its caller's stack by. If the caller is a compiled frame then
741 // we pretend that the callee has no parameters so that the
742 // extension counts for the full amount of locals and not just
743 // locals-parms. This is because without a c2i adapter the parm
744 // area as created by the compiled frame will not be usable by
745 // the interpreter. (Depending on the calling convention there
746 // may not even be enough space).
747
748 // QQQ I'd rather see this pushed down into last_frame_adjust
749 // and have it take the sender (aka caller).
750
751 if (!deopt_sender.is_interpreted_frame() || caller_was_method_handle) {
752 caller_adjustment = last_frame_adjust(0, callee_locals);
753 } else if (callee_locals > callee_parameters) {
754 // The caller frame may need extending to accommodate
755 // non-parameter locals of the first unpacked interpreted frame.
756 // Compute that adjustment.
757 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
758 }
759
760 // If the sender is deoptimized we must retrieve the address of the handler
761 // since the frame will "magically" show the original pc before the deopt
762 // and we'd undo the deopt.
763
764 frame_pcs[0] = Continuation::is_cont_barrier_frame(deoptee) ? StubRoutines::cont_returnBarrier() : deopt_sender.raw_pc();
765 if (Continuation::is_continuation_enterSpecial(deopt_sender)) {
766 ContinuationEntry::from_frame(deopt_sender)->set_argsize(0);
767 }
768
769 assert(CodeCache::find_blob(frame_pcs[0]) != nullptr, "bad pc");
770
771 if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
772 assert(current->has_pending_exception(), "should have thrown OOME");
773 current->set_exception_oop(current->pending_exception());
774 current->clear_pending_exception();
775 exec_mode = Unpack_exception;
776 }
777
778 int caller_actual_parameters = -1; // value not used except for interpreted frames, see below
779 if (deopt_sender.is_interpreted_frame()) {
780 caller_actual_parameters = callee_parameters + (caller_was_method_handle ? 1 : 0);
781 }
782
783 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
784 caller_adjustment * BytesPerWord,
785 caller_actual_parameters,
786 number_of_frames,
787 frame_sizes,
788 frame_pcs,
789 return_type,
790 exec_mode);
791 // On some platforms, we need a way to pass some platform dependent
792 // information to the unpacking code so the skeletal frames come out
793 // correct (initial fp value, unextended sp, ...)
794 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
795
796 if (array->frames() > 1) {
797 if (VerifyStack && TraceDeoptimization) {
798 tty->print_cr("Deoptimizing method containing inlining");
799 }
800 }
801
802 array->set_unroll_block(info);
803 return info;
804 }
805
806 // Called to cleanup deoptimization data structures in normal case
807 // after unpacking to stack and when stack overflow error occurs
808 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
809 vframeArray *array) {
810
811 // Get array if coming from exception
812 if (array == nullptr) {
813 array = thread->vframe_array_head();
814 }
815 thread->set_vframe_array_head(nullptr);
816
817 // Free the previous UnrollBlock
818 vframeArray* old_array = thread->vframe_array_last();
819 thread->set_vframe_array_last(array);
820
821 if (old_array != nullptr) {
822 UnrollBlock* old_info = old_array->unroll_block();
823 old_array->set_unroll_block(nullptr);
824 delete old_info;
825 delete old_array;
826 }
827
828 // Deallocate any resource creating in this routine and any ResourceObjs allocated
829 // inside the vframeArray (StackValueCollections)
830
831 delete thread->deopt_mark();
832 thread->set_deopt_mark(nullptr);
833 thread->set_deopt_compiled_method(nullptr);
834
835
836 if (JvmtiExport::can_pop_frame()) {
837 // Regardless of whether we entered this routine with the pending
838 // popframe condition bit set, we should always clear it now
839 thread->clear_popframe_condition();
840 }
841
842 // unpack_frames() is called at the end of the deoptimization handler
843 // and (in C2) at the end of the uncommon trap handler. Note this fact
844 // so that an asynchronous stack walker can work again. This counter is
845 // incremented at the beginning of fetch_unroll_info() and (in C2) at
846 // the beginning of uncommon_trap().
847 thread->dec_in_deopt_handler();
848 }
849
850 // Moved from cpu directories because none of the cpus has callee save values.
851 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
852 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
853
854 // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
855 // the days we had adapter frames. When we deoptimize a situation where a
856 // compiled caller calls a compiled caller will have registers it expects
857 // to survive the call to the callee. If we deoptimize the callee the only
858 // way we can restore these registers is to have the oldest interpreter
859 // frame that we create restore these values. That is what this routine
860 // will accomplish.
861
862 // At the moment we have modified c2 to not have any callee save registers
863 // so this problem does not exist and this routine is just a place holder.
864
865 assert(f->is_interpreted_frame(), "must be interpreted");
866 }
867
868 #ifndef PRODUCT
869 #ifdef ASSERT
870 // Return true if the execution after the provided bytecode continues at the
871 // next bytecode in the code. This is not the case for gotos, returns, and
872 // throws.
873 static bool falls_through(Bytecodes::Code bc) {
874 switch (bc) {
875 case Bytecodes::_goto:
876 case Bytecodes::_goto_w:
877 case Bytecodes::_athrow:
878 case Bytecodes::_areturn:
879 case Bytecodes::_dreturn:
880 case Bytecodes::_freturn:
881 case Bytecodes::_ireturn:
882 case Bytecodes::_lreturn:
883 case Bytecodes::_jsr:
884 case Bytecodes::_ret:
885 case Bytecodes::_return:
886 case Bytecodes::_lookupswitch:
887 case Bytecodes::_tableswitch:
888 return false;
889 default:
890 return true;
891 }
892 }
893 #endif
894 #endif
895
896 // Return BasicType of value being returned
897 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
898 assert(thread == JavaThread::current(), "pre-condition");
899
900 // We are already active in the special DeoptResourceMark any ResourceObj's we
901 // allocate will be freed at the end of the routine.
902
903 // JRT_LEAF methods don't normally allocate handles and there is a
904 // NoHandleMark to enforce that. It is actually safe to use Handles
905 // in a JRT_LEAF method, and sometimes desirable, but to do so we
906 // must use ResetNoHandleMark to bypass the NoHandleMark, and
907 // then use a HandleMark to ensure any Handles we do create are
908 // cleaned up in this scope.
909 ResetNoHandleMark rnhm;
910 HandleMark hm(thread);
911
912 frame stub_frame = thread->last_frame();
913
914 Continuation::notify_deopt(thread, stub_frame.sp());
915
916 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
917 // must point to the vframeArray for the unpack frame.
918 vframeArray* array = thread->vframe_array_head();
919 UnrollBlock* info = array->unroll_block();
920
921 // We set the last_Java frame. But the stack isn't really parsable here. So we
922 // clear it to make sure JFR understands not to try and walk stacks from events
923 // in here.
924 intptr_t* sp = thread->frame_anchor()->last_Java_sp();
925 thread->frame_anchor()->set_last_Java_sp(nullptr);
926
927 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
928 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
929
930 thread->frame_anchor()->set_last_Java_sp(sp);
931
932 BasicType bt = info->return_type();
933
934 // If we have an exception pending, claim that the return type is an oop
935 // so the deopt_blob does not overwrite the exception_oop.
936
937 if (exec_mode == Unpack_exception)
938 bt = T_OBJECT;
939
940 // Cleanup thread deopt data
941 cleanup_deopt_info(thread, array);
942
943 #ifndef PRODUCT
944 if (VerifyStack) {
945 ResourceMark res_mark;
946 // Clear pending exception to not break verification code (restored afterwards)
947 PreserveExceptionMark pm(thread);
948
949 thread->validate_frame_layout();
950
951 // Verify that the just-unpacked frames match the interpreter's
952 // notions of expression stack and locals
953 vframeArray* cur_array = thread->vframe_array_last();
954 RegisterMap rm(thread,
955 RegisterMap::UpdateMap::skip,
956 RegisterMap::ProcessFrames::include,
957 RegisterMap::WalkContinuation::skip);
958 rm.set_include_argument_oops(false);
959 int callee_size_of_parameters = 0;
960 for (int frame_idx = 0; frame_idx < cur_array->frames(); frame_idx++) {
961 bool is_top_frame = (frame_idx == 0);
962 vframeArrayElement* el = cur_array->element(frame_idx);
963 frame* iframe = el->iframe();
964 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
965 methodHandle mh(thread, iframe->interpreter_frame_method());
966 bool reexecute = el->should_reexecute();
967
968 int cur_invoke_parameter_size = 0;
969 int top_frame_expression_stack_adjustment = 0;
970 int max_bci = mh->code_size();
971 BytecodeStream str(mh, iframe->interpreter_frame_bci());
972 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
973 Bytecodes::Code cur_code = str.next();
974
975 if (!reexecute && !Bytecodes::is_invoke(cur_code)) {
976 // We can only compute OopMaps for the before state, so we need to roll forward
977 // to the next bytecode.
978 assert(is_top_frame, "must be");
979 assert(falls_through(cur_code), "must be");
980 assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
981 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
982
983 // Need to subtract off the size of the result type of
984 // the bytecode because this is not described in the
985 // debug info but returned to the interpreter in the TOS
986 // caching register
987 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
988 if (bytecode_result_type != T_ILLEGAL) {
989 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
990 }
991 assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
992
993 cur_code = str.next();
994 // Reflect the fact that we have rolled forward and now need
995 // top_frame_expression_stack_adjustment
996 reexecute = true;
997 }
998
999 assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
1000 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
1001
1002 // Get the oop map for this bci
1003 InterpreterOopMap mask;
1004 OopMapCache::compute_one_oop_map(mh, str.bci(), &mask);
1005 // Check to see if we can grab the number of outgoing arguments
1006 // at an uncommon trap for an invoke (where the compiler
1007 // generates debug info before the invoke has executed)
1008 if (Bytecodes::is_invoke(cur_code)) {
1009 Bytecode_invoke invoke(mh, str.bci());
1010 cur_invoke_parameter_size = invoke.size_of_parameters();
1011 if (!is_top_frame && invoke.has_member_arg()) {
1012 callee_size_of_parameters++;
1013 }
1014 }
1015
1016 // Verify stack depth and oops in frame
1017 auto match = [&]() {
1018 int iframe_expr_ssize = iframe->interpreter_frame_expression_stack_size();
1019 // This should only be needed for C1
1020 if (is_top_frame && exec_mode == Unpack_exception && iframe_expr_ssize == 0) {
1021 return true;
1022 }
1023 if (reexecute) {
1024 int expr_ssize_before = iframe_expr_ssize + top_frame_expression_stack_adjustment;
1025 int oopmap_expr_invoke_ssize = mask.expression_stack_size() + cur_invoke_parameter_size;
1026 return expr_ssize_before == oopmap_expr_invoke_ssize;
1027 } else {
1028 int oopmap_expr_callee_ssize = mask.expression_stack_size() + callee_size_of_parameters;
1029 return iframe_expr_ssize == oopmap_expr_callee_ssize;
1030 }
1031 };
1032 if (!match()) {
1033 // Print out some information that will help us debug the problem
1034 tty->print_cr("Wrong number of expression stack elements during deoptimization");
1035 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", frame_idx, cur_array->frames() - 1);
1036 tty->print_cr(" Current code %s", Bytecodes::name(cur_code));
1037 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
1038 iframe->interpreter_frame_expression_stack_size());
1039 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
1040 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
1041 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
1042 tty->print_cr(" exec_mode = %d", exec_mode);
1043 tty->print_cr(" original should_reexecute = %s", el->should_reexecute() ? "true" : "false");
1044 tty->print_cr(" reexecute = %s%s", reexecute ? "true" : "false",
1045 (reexecute != el->should_reexecute()) ? " (changed)" : "");
1046 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
1047 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
1048 tty->print_cr(" Interpreted frames:");
1049 for (int k = 0; k < cur_array->frames(); k++) {
1050 vframeArrayElement* el = cur_array->element(k);
1051 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
1052 }
1053 cur_array->print_on_2(tty);
1054 guarantee(false, "wrong number of expression stack elements during deopt");
1055 }
1056 VerifyOopClosure verify;
1057 iframe->oops_interpreted_do(&verify, &rm, false);
1058 callee_size_of_parameters = mh->size_of_parameters();
1059 }
1060 }
1061 #endif // !PRODUCT
1062
1063 return bt;
1064 JRT_END
1065
1066 class DeoptimizeMarkedHandshakeClosure : public HandshakeClosure {
1067 public:
1068 DeoptimizeMarkedHandshakeClosure() : HandshakeClosure("Deoptimize") {}
1069 void do_thread(Thread* thread) {
1070 JavaThread* jt = JavaThread::cast(thread);
1071 jt->deoptimize_marked_methods();
1072 }
1073 };
1074
1075 void Deoptimization::deoptimize_all_marked() {
1076 ResourceMark rm;
1077
1078 // Make the dependent methods not entrant
1079 CodeCache::make_marked_nmethods_deoptimized();
1080
1081 DeoptimizeMarkedHandshakeClosure deopt;
1082 if (SafepointSynchronize::is_at_safepoint()) {
1083 Threads::java_threads_do(&deopt);
1084 } else {
1085 Handshake::execute(&deopt);
1086 }
1087 }
1088
1089 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1090 = Deoptimization::Action_reinterpret;
1091
1092 #ifdef COMPILER2
1093 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1094 Handle pending_exception(THREAD, thread->pending_exception());
1095 const char* exception_file = thread->exception_file();
1096 int exception_line = thread->exception_line();
1097 thread->clear_pending_exception();
1098
1099 bool failures = false;
1100
1101 for (int i = 0; i < objects->length(); i++) {
1102 assert(objects->at(i)->is_object(), "invalid debug information");
1103 ObjectValue* sv = (ObjectValue*) objects->at(i);
1104
1105 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1106
1107 k = get_refined_array_klass(k, fr, reg_map, sv, THREAD);
1108
1109 // Check if the object may be null and has an additional null_marker input that needs
1110 // to be checked before using the field values. Skip re-allocation if it is null.
1111 if (k->is_inline_klass() && sv->has_properties()) {
1112 jint null_marker = StackValue::create_stack_value(fr, reg_map, sv->properties())->get_jint();
1113 if (null_marker == 0) {
1114 continue;
1115 }
1116 }
1117
1118 oop obj = nullptr;
1119 bool cache_init_error = false;
1120 if (k->is_instance_klass()) {
1121 InstanceKlass* ik = InstanceKlass::cast(k);
1122 if (obj == nullptr && !cache_init_error) {
1123 InternalOOMEMark iom(THREAD);
1124 if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1125 obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1126 } else {
1127 obj = ik->allocate_instance(THREAD);
1128 }
1129 }
1130 } else if (k->is_flatArray_klass()) {
1131 FlatArrayKlass* ak = FlatArrayKlass::cast(k);
1132 // Inline type array must be zeroed because not all memory is reassigned
1133 InternalOOMEMark iom(THREAD);
1134 obj = ak->allocate_instance(sv->field_size(), THREAD);
1135 } else if (k->is_typeArray_klass()) {
1136 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1137 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1138 int len = sv->field_size() / type2size[ak->element_type()];
1139 InternalOOMEMark iom(THREAD);
1140 obj = ak->allocate_instance(len, THREAD);
1141 } else if (k->is_refArray_klass()) {
1142 RefArrayKlass* ak = RefArrayKlass::cast(k);
1143 InternalOOMEMark iom(THREAD);
1144 obj = ak->allocate_instance(sv->field_size(), THREAD);
1145 }
1146
1147 if (obj == nullptr) {
1148 failures = true;
1149 }
1150
1151 assert(sv->value().is_null(), "redundant reallocation");
1152 assert(obj != nullptr || HAS_PENDING_EXCEPTION || cache_init_error, "allocation should succeed or we should get an exception");
1153 CLEAR_PENDING_EXCEPTION;
1154 sv->set_value(obj);
1155 }
1156
1157 if (failures) {
1158 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1159 } else if (pending_exception.not_null()) {
1160 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1161 }
1162
1163 return failures;
1164 }
1165
1166 // We're deoptimizing at the return of a call, inline type fields are
1167 // in registers. When we go back to the interpreter, it will expect a
1168 // reference to an inline type instance. Allocate and initialize it from
1169 // the register values here.
1170 bool Deoptimization::realloc_inline_type_result(InlineKlass* vk, const RegisterMap& map, GrowableArray<Handle>& return_oops, TRAPS) {
1171 oop new_vt = vk->realloc_result(map, return_oops, THREAD);
1172 if (new_vt == nullptr) {
1173 CLEAR_PENDING_EXCEPTION;
1174 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), true);
1175 }
1176 return_oops.clear();
1177 return_oops.push(Handle(THREAD, new_vt));
1178 return false;
1179 }
1180
1181 // restore elements of an eliminated type array
1182 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1183 int index = 0;
1184
1185 for (int i = 0; i < sv->field_size(); i++) {
1186 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1187 switch(type) {
1188 case T_LONG: case T_DOUBLE: {
1189 assert(value->type() == T_INT, "Agreement.");
1190 StackValue* low =
1191 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1192 #ifdef _LP64
1193 jlong res = (jlong)low->get_intptr();
1194 #else
1195 jlong res = jlong_from(value->get_jint(), low->get_jint());
1196 #endif
1197 obj->long_at_put(index, res);
1198 break;
1199 }
1200
1201 case T_INT: case T_FLOAT: { // 4 bytes.
1202 assert(value->type() == T_INT, "Agreement.");
1203 obj->int_at_put(index, value->get_jint());
1204 break;
1205 }
1206
1207 case T_SHORT:
1208 assert(value->type() == T_INT, "Agreement.");
1209 obj->short_at_put(index, (jshort)value->get_jint());
1210 break;
1211
1212 case T_CHAR:
1213 assert(value->type() == T_INT, "Agreement.");
1214 obj->char_at_put(index, (jchar)value->get_jint());
1215 break;
1216
1217 case T_BYTE: {
1218 assert(value->type() == T_INT, "Agreement.");
1219 obj->byte_at_put(index, (jbyte)value->get_jint());
1220 break;
1221 }
1222
1223 case T_BOOLEAN: {
1224 assert(value->type() == T_INT, "Agreement.");
1225 obj->bool_at_put(index, (jboolean)value->get_jint());
1226 break;
1227 }
1228
1229 default:
1230 ShouldNotReachHere();
1231 }
1232 index++;
1233 }
1234 }
1235
1236 // restore fields of an eliminated object array
1237 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1238 for (int i = 0; i < sv->field_size(); i++) {
1239 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1240 assert(value->type() == T_OBJECT, "object element expected");
1241 obj->obj_at_put(i, value->get_obj()());
1242 }
1243 }
1244
1245 class ReassignedField {
1246 public:
1247 int _offset;
1248 BasicType _type;
1249 InstanceKlass* _klass;
1250 bool _is_flat;
1251 bool _is_null_free;
1252 public:
1253 ReassignedField() : _offset(0), _type(T_ILLEGAL), _klass(nullptr), _is_flat(false), _is_null_free(false) { }
1254 };
1255
1256 // Gets the fields of `klass` that are eliminated by escape analysis and need to be reassigned
1257 static GrowableArray<ReassignedField>* get_reassigned_fields(InstanceKlass* klass, GrowableArray<ReassignedField>* fields) {
1258 InstanceKlass* super = klass->super();
1259 if (super != nullptr) {
1260 get_reassigned_fields(super, fields);
1261 }
1262 for (AllFieldStream fs(klass); !fs.done(); fs.next()) {
1263 if (!fs.access_flags().is_static() && !fs.field_flags().is_injected()) {
1264 ReassignedField field;
1265 field._offset = fs.offset();
1266 field._type = Signature::basic_type(fs.signature());
1267 if (fs.is_flat()) {
1268 field._is_flat = true;
1269 field._is_null_free = fs.is_null_free_inline_type();
1270 // Resolve klass of flat inline type field
1271 field._klass = InlineKlass::cast(klass->get_inline_type_field_klass(fs.index()));
1272 }
1273 fields->append(field);
1274 }
1275 }
1276 return fields;
1277 }
1278
1279 // Restore fields of an eliminated instance object employing the same field order used by the
1280 // compiler when it scalarizes an object at safepoints.
1281 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, int base_offset, TRAPS) {
1282 GrowableArray<ReassignedField>* fields = get_reassigned_fields(klass, new GrowableArray<ReassignedField>());
1283 for (int i = 0; i < fields->length(); i++) {
1284 BasicType type = fields->at(i)._type;
1285 int offset = base_offset + fields->at(i)._offset;
1286 // Check for flat inline type field before accessing the ScopeValue because it might not have any fields
1287 if (fields->at(i)._is_flat) {
1288 // Recursively re-assign flat inline type fields
1289 InstanceKlass* vk = fields->at(i)._klass;
1290 assert(vk != nullptr, "must be resolved");
1291 offset -= InlineKlass::cast(vk)->payload_offset(); // Adjust offset to omit oop header
1292 svIndex = reassign_fields_by_klass(vk, fr, reg_map, sv, svIndex, obj, offset, CHECK_0);
1293 if (!fields->at(i)._is_null_free) {
1294 ScopeValue* scope_field = sv->field_at(svIndex);
1295 StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1296 int nm_offset = offset + InlineKlass::cast(vk)->null_marker_offset();
1297 obj->bool_field_put(nm_offset, value->get_jint() & 1);
1298 svIndex++;
1299 }
1300 continue; // Continue because we don't need to increment svIndex
1301 }
1302
1303 ScopeValue* scope_field = sv->field_at(svIndex);
1304 StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1305 switch (type) {
1306 case T_OBJECT: case T_ARRAY:
1307 assert(value->type() == T_OBJECT, "Agreement.");
1308 obj->obj_field_put(offset, value->get_obj()());
1309 break;
1310
1311 case T_INT: case T_FLOAT: { // 4 bytes.
1312 assert(value->type() == T_INT, "Agreement.");
1313 bool big_value = false;
1314 if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1315 if (scope_field->is_location()) {
1316 Location::Type type = ((LocationValue*) scope_field)->location().type();
1317 if (type == Location::dbl || type == Location::lng) {
1318 big_value = true;
1319 }
1320 }
1321 if (scope_field->is_constant_int()) {
1322 ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1323 if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1324 big_value = true;
1325 }
1326 }
1327 }
1328
1329 if (big_value) {
1330 i++;
1331 assert(i < fields->length(), "second T_INT field needed");
1332 assert(fields->at(i)._type == T_INT, "T_INT field needed");
1333 } else {
1334 obj->int_field_put(offset, value->get_jint());
1335 break;
1336 }
1337 }
1338 /* no break */
1339
1340 case T_LONG: case T_DOUBLE: {
1341 assert(value->type() == T_INT, "Agreement.");
1342 StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1343 #ifdef _LP64
1344 jlong res = (jlong)low->get_intptr();
1345 #else
1346 jlong res = jlong_from(value->get_jint(), low->get_jint());
1347 #endif
1348 obj->long_field_put(offset, res);
1349 break;
1350 }
1351
1352 case T_SHORT:
1353 assert(value->type() == T_INT, "Agreement.");
1354 obj->short_field_put(offset, (jshort)value->get_jint());
1355 break;
1356
1357 case T_CHAR:
1358 assert(value->type() == T_INT, "Agreement.");
1359 obj->char_field_put(offset, (jchar)value->get_jint());
1360 break;
1361
1362 case T_BYTE:
1363 assert(value->type() == T_INT, "Agreement.");
1364 obj->byte_field_put(offset, (jbyte)value->get_jint());
1365 break;
1366
1367 case T_BOOLEAN:
1368 assert(value->type() == T_INT, "Agreement.");
1369 obj->bool_field_put(offset, (jboolean)value->get_jint());
1370 break;
1371
1372 default:
1373 ShouldNotReachHere();
1374 }
1375 svIndex++;
1376 }
1377 return svIndex;
1378 }
1379
1380 // restore fields of an eliminated inline type array
1381 void Deoptimization::reassign_flat_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, flatArrayOop obj, FlatArrayKlass* vak, TRAPS) {
1382 InlineKlass* vk = vak->element_klass();
1383 assert(vk->maybe_flat_in_array(), "should only be used for flat inline type arrays");
1384 // Adjust offset to omit oop header
1385 int base_offset = arrayOopDesc::base_offset_in_bytes(T_FLAT_ELEMENT) - vk->payload_offset();
1386 // Initialize all elements of the flat inline type array
1387 for (int i = 0; i < sv->field_size(); i++) {
1388 ObjectValue* val = sv->field_at(i)->as_ObjectValue();
1389 int offset = base_offset + (i << Klass::layout_helper_log2_element_size(vak->layout_helper()));
1390 reassign_fields_by_klass(vk, fr, reg_map, val, 0, (oop)obj, offset, CHECK);
1391 if (!obj->is_null_free_array()) {
1392 jboolean null_marker_value;
1393 if (val->has_properties()) {
1394 null_marker_value = StackValue::create_stack_value(fr, reg_map, val->properties())->get_jint() & 1;
1395 } else {
1396 null_marker_value = 1;
1397 }
1398 obj->bool_field_put(offset + vk->null_marker_offset(), null_marker_value);
1399 }
1400 }
1401 }
1402
1403 // restore fields of all eliminated objects and arrays
1404 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, TRAPS) {
1405 for (int i = 0; i < objects->length(); i++) {
1406 assert(objects->at(i)->is_object(), "invalid debug information");
1407 ObjectValue* sv = (ObjectValue*) objects->at(i);
1408 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1409 k = get_refined_array_klass(k, fr, reg_map, sv, THREAD);
1410
1411 Handle obj = sv->value();
1412 assert(obj.not_null() || realloc_failures || sv->has_properties(), "reallocation was missed");
1413 #ifndef PRODUCT
1414 if (PrintDeoptimizationDetails) {
1415 tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1416 }
1417 #endif // !PRODUCT
1418
1419 if (obj.is_null()) {
1420 continue;
1421 }
1422
1423 if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1424 assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1425 ScopeValue* payload = sv->field_at(0);
1426 if (payload->is_location() &&
1427 payload->as_LocationValue()->location().type() == Location::vector) {
1428 #ifndef PRODUCT
1429 if (PrintDeoptimizationDetails) {
1430 tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1431 if (Verbose) {
1432 Handle obj = sv->value();
1433 k->oop_print_on(obj(), tty);
1434 }
1435 }
1436 #endif // !PRODUCT
1437 continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1438 }
1439 // Else fall-through to do assignment for scalar-replaced boxed vector representation
1440 // which could be restored after vector object allocation.
1441 }
1442 if (k->is_instance_klass()) {
1443 InstanceKlass* ik = InstanceKlass::cast(k);
1444 reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), 0, CHECK);
1445 } else if (k->is_flatArray_klass()) {
1446 FlatArrayKlass* vak = FlatArrayKlass::cast(k);
1447 reassign_flat_array_elements(fr, reg_map, sv, (flatArrayOop) obj(), vak, CHECK);
1448 } else if (k->is_typeArray_klass()) {
1449 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1450 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1451 } else if (k->is_refArray_klass()) {
1452 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1453 }
1454 }
1455 // These objects may escape when we return to Interpreter after deoptimization.
1456 // We need barrier so that stores that initialize these objects can't be reordered
1457 // with subsequent stores that make these objects accessible by other threads.
1458 OrderAccess::storestore();
1459 }
1460
1461
1462 // relock objects for which synchronization was eliminated
1463 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1464 JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1465 bool relocked_objects = false;
1466 for (int i = 0; i < monitors->length(); i++) {
1467 MonitorInfo* mon_info = monitors->at(i);
1468 if (mon_info->eliminated()) {
1469 assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1470 relocked_objects = true;
1471 if (!mon_info->owner_is_scalar_replaced()) {
1472 Handle obj(thread, mon_info->owner());
1473 markWord mark = obj->mark();
1474 if (exec_mode == Unpack_none) {
1475 if (mark.has_monitor()) {
1476 // defer relocking if the deoptee thread is currently waiting for obj
1477 ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1478 if (waiting_monitor != nullptr && waiting_monitor->object() == obj()) {
1479 assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1480 if (UseObjectMonitorTable) {
1481 mon_info->lock()->clear_object_monitor_cache();
1482 }
1483 #ifdef ASSERT
1484 else {
1485 assert(!UseObjectMonitorTable, "must be");
1486 mon_info->lock()->set_bad_monitor_deopt();
1487 }
1488 #endif
1489 JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1490 continue;
1491 }
1492 }
1493 }
1494 BasicLock* lock = mon_info->lock();
1495 // We have lost information about the correct state of the lock stack.
1496 // Entering may create an invalid lock stack. Inflate the lock if it
1497 // was fast_locked to restore the valid lock stack.
1498 if (UseObjectMonitorTable) {
1499 // UseObjectMonitorTable expects the BasicLock cache to be either a
1500 // valid ObjectMonitor* or nullptr. Right now it is garbage, set it
1501 // to nullptr.
1502 lock->clear_object_monitor_cache();
1503 }
1504 ObjectSynchronizer::enter_for(obj, lock, deoptee_thread);
1505 if (deoptee_thread->lock_stack().contains(obj())) {
1506 ObjectSynchronizer::inflate_fast_locked_object(obj(), ObjectSynchronizer::InflateCause::inflate_cause_vm_internal,
1507 deoptee_thread, thread);
1508 }
1509 assert(mon_info->owner()->is_locked(), "object must be locked now");
1510 assert(obj->mark().has_monitor(), "must be");
1511 assert(!deoptee_thread->lock_stack().contains(obj()), "must be");
1512 assert(ObjectSynchronizer::read_monitor(obj(), obj->mark())->has_owner(deoptee_thread), "must be");
1513 }
1514 }
1515 }
1516 return relocked_objects;
1517 }
1518 #endif // COMPILER2
1519
1520 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1521 Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1522
1523 // Register map for next frame (used for stack crawl). We capture
1524 // the state of the deopt'ing frame's caller. Thus if we need to
1525 // stuff a C2I adapter we can properly fill in the callee-save
1526 // register locations.
1527 frame caller = fr.sender(reg_map);
1528 int frame_size = pointer_delta_as_int(caller.sp(), fr.sp());
1529
1530 frame sender = caller;
1531
1532 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1533 // the vframeArray containing the unpacking information is allocated in the C heap.
1534 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1535 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1536
1537 // Compare the vframeArray to the collected vframes
1538 assert(array->structural_compare(thread, chunk), "just checking");
1539
1540 if (TraceDeoptimization) {
1541 ResourceMark rm;
1542 stringStream st;
1543 st.print_cr("DEOPT PACKING thread=" INTPTR_FORMAT " vframeArray=" INTPTR_FORMAT, p2i(thread), p2i(array));
1544 st.print(" ");
1545 fr.print_on(&st);
1546 st.print_cr(" Virtual frames (innermost/newest first):");
1547 for (int index = 0; index < chunk->length(); index++) {
1548 compiledVFrame* vf = chunk->at(index);
1549 int bci = vf->raw_bci();
1550 const char* code_name;
1551 if (bci == SynchronizationEntryBCI) {
1552 code_name = "sync entry";
1553 } else {
1554 Bytecodes::Code code = vf->method()->code_at(bci);
1555 code_name = Bytecodes::name(code);
1556 }
1557
1558 st.print(" VFrame %d (" INTPTR_FORMAT ")", index, p2i(vf));
1559 st.print(" - %s", vf->method()->name_and_sig_as_C_string());
1560 st.print(" - %s", code_name);
1561 st.print_cr(" @ bci=%d ", bci);
1562 }
1563 tty->print_raw(st.freeze());
1564 tty->cr();
1565 }
1566
1567 return array;
1568 }
1569
1570 #ifdef COMPILER2
1571 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1572 // Reallocation of some scalar replaced objects failed. Record
1573 // that we need to pop all the interpreter frames for the
1574 // deoptimized compiled frame.
1575 assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1576 thread->set_frames_to_pop_failed_realloc(array->frames());
1577 // Unlock all monitors here otherwise the interpreter will see a
1578 // mix of locked and unlocked monitors (because of failed
1579 // reallocations of synchronized objects) and be confused.
1580 for (int i = 0; i < array->frames(); i++) {
1581 MonitorChunk* monitors = array->element(i)->monitors();
1582 if (monitors != nullptr) {
1583 // Unlock in reverse order starting from most nested monitor.
1584 for (int j = (monitors->number_of_monitors() - 1); j >= 0; j--) {
1585 BasicObjectLock* src = monitors->at(j);
1586 if (src->obj() != nullptr) {
1587 ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1588 }
1589 }
1590 array->element(i)->free_monitors();
1591 #ifdef ASSERT
1592 array->element(i)->set_removed_monitors();
1593 #endif // ASSERT
1594 }
1595 }
1596 }
1597 #endif // COMPILER2
1598
1599 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1600 assert(fr.can_be_deoptimized(), "checking frame type");
1601
1602 gather_statistics(reason, Action_none, Bytecodes::_illegal);
1603
1604 if (LogCompilation && xtty != nullptr) {
1605 nmethod* nm = fr.cb()->as_nmethod_or_null();
1606 assert(nm != nullptr, "only compiled methods can deopt");
1607
1608 ttyLocker ttyl;
1609 xtty->begin_head("deoptimized thread='%zu' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1610 nm->log_identity(xtty);
1611 xtty->end_head();
1612 for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1613 xtty->begin_elem("jvms bci='%d'", sd->bci());
1614 xtty->method(sd->method());
1615 xtty->end_elem();
1616 if (sd->is_top()) break;
1617 }
1618 xtty->tail("deoptimized");
1619 }
1620
1621 Continuation::notify_deopt(thread, fr.sp());
1622
1623 // Patch the compiled method so that when execution returns to it we will
1624 // deopt the execution state and return to the interpreter.
1625 fr.deoptimize(thread);
1626 }
1627
1628 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1629 // Deoptimize only if the frame comes from compiled code.
1630 // Do not deoptimize the frame which is already patched
1631 // during the execution of the loops below.
1632 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1633 return;
1634 }
1635 ResourceMark rm;
1636 deoptimize_single_frame(thread, fr, reason);
1637 }
1638
1639 address Deoptimization::deoptimize_for_missing_exception_handler(nmethod* nm, bool make_not_entrant) {
1640 // there is no exception handler for this pc => deoptimize
1641 if (make_not_entrant) {
1642 nm->make_not_entrant(nmethod::InvalidationReason::MISSING_EXCEPTION_HANDLER);
1643 }
1644
1645 // Use Deoptimization::deoptimize for all of its side-effects:
1646 // gathering traps statistics, logging...
1647 // it also patches the return pc but we do not care about that
1648 // since we return a continuation to the deopt_blob below.
1649 JavaThread* thread = JavaThread::current();
1650 RegisterMap reg_map(thread,
1651 RegisterMap::UpdateMap::skip,
1652 RegisterMap::ProcessFrames::include,
1653 RegisterMap::WalkContinuation::skip);
1654 frame runtime_frame = thread->last_frame();
1655 frame caller_frame = runtime_frame.sender(®_map);
1656 assert(caller_frame.cb()->as_nmethod_or_null() == nm, "expect top frame compiled method");
1657
1658 Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1659
1660 return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1661 }
1662
1663 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1664 assert(thread == Thread::current() ||
1665 thread->is_handshake_safe_for(Thread::current()) ||
1666 SafepointSynchronize::is_at_safepoint(),
1667 "can only deoptimize other thread at a safepoint/handshake");
1668 // Compute frame and register map based on thread and sp.
1669 RegisterMap reg_map(thread,
1670 RegisterMap::UpdateMap::skip,
1671 RegisterMap::ProcessFrames::include,
1672 RegisterMap::WalkContinuation::skip);
1673 frame fr = thread->last_frame();
1674 while (fr.id() != id) {
1675 fr = fr.sender(®_map);
1676 }
1677 deoptimize(thread, fr, reason);
1678 }
1679
1680
1681 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1682 Thread* current = Thread::current();
1683 if (thread == current || thread->is_handshake_safe_for(current)) {
1684 Deoptimization::deoptimize_frame_internal(thread, id, reason);
1685 } else {
1686 VM_DeoptimizeFrame deopt(thread, id, reason);
1687 VMThread::execute(&deopt);
1688 }
1689 }
1690
1691 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1692 deoptimize_frame(thread, id, Reason_constraint);
1693 }
1694
1695 // JVMTI PopFrame support
1696 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1697 {
1698 assert(thread == JavaThread::current(), "pre-condition");
1699 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1700 }
1701 JRT_END
1702
1703 MethodData*
1704 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1705 bool create_if_missing) {
1706 JavaThread* THREAD = thread; // For exception macros.
1707 MethodData* mdo = m()->method_data();
1708 if (mdo == nullptr && create_if_missing && !HAS_PENDING_EXCEPTION) {
1709 // Build an MDO. Ignore errors like OutOfMemory;
1710 // that simply means we won't have an MDO to update.
1711 Method::build_profiling_method_data(m, THREAD);
1712 if (HAS_PENDING_EXCEPTION) {
1713 // Only metaspace OOM is expected. No Java code executed.
1714 assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1715 CLEAR_PENDING_EXCEPTION;
1716 }
1717 mdo = m()->method_data();
1718 }
1719 return mdo;
1720 }
1721
1722 #ifdef COMPILER2
1723 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1724 // In case of an unresolved klass entry, load the class.
1725 // This path is exercised from case _ldc in Parse::do_one_bytecode,
1726 // and probably nowhere else.
1727 // Even that case would benefit from simply re-interpreting the
1728 // bytecode, without paying special attention to the class index.
1729 // So this whole "class index" feature should probably be removed.
1730
1731 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1732 Klass* tk = constant_pool->klass_at(index, THREAD);
1733 if (HAS_PENDING_EXCEPTION) {
1734 // Exception happened during classloading. We ignore the exception here, since it
1735 // is going to be rethrown since the current activation is going to be deoptimized and
1736 // the interpreter will re-execute the bytecode.
1737 // Do not clear probable Async Exceptions.
1738 CLEAR_PENDING_NONASYNC_EXCEPTION;
1739 // Class loading called java code which may have caused a stack
1740 // overflow. If the exception was thrown right before the return
1741 // to the runtime the stack is no longer guarded. Reguard the
1742 // stack otherwise if we return to the uncommon trap blob and the
1743 // stack bang causes a stack overflow we crash.
1744 JavaThread* jt = THREAD;
1745 bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1746 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1747 }
1748 return;
1749 }
1750
1751 assert(!constant_pool->tag_at(index).is_symbol(),
1752 "no symbolic names here, please");
1753 }
1754
1755 #if INCLUDE_JFR
1756
1757 class DeoptReasonSerializer : public JfrSerializer {
1758 public:
1759 void serialize(JfrCheckpointWriter& writer) {
1760 writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
1761 for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
1762 writer.write_key((u8)i);
1763 writer.write(Deoptimization::trap_reason_name(i));
1764 }
1765 }
1766 };
1767
1768 class DeoptActionSerializer : public JfrSerializer {
1769 public:
1770 void serialize(JfrCheckpointWriter& writer) {
1771 static const u4 nof_actions = Deoptimization::Action_LIMIT;
1772 writer.write_count(nof_actions);
1773 for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
1774 writer.write_key(i);
1775 writer.write(Deoptimization::trap_action_name((int)i));
1776 }
1777 }
1778 };
1779
1780 static void register_serializers() {
1781 static int critical_section = 0;
1782 if (1 == critical_section || AtomicAccess::cmpxchg(&critical_section, 0, 1) == 1) {
1783 return;
1784 }
1785 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
1786 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
1787 }
1788
1789 static void post_deoptimization_event(nmethod* nm,
1790 const Method* method,
1791 int trap_bci,
1792 int instruction,
1793 Deoptimization::DeoptReason reason,
1794 Deoptimization::DeoptAction action) {
1795 assert(nm != nullptr, "invariant");
1796 assert(method != nullptr, "invariant");
1797 if (EventDeoptimization::is_enabled()) {
1798 static bool serializers_registered = false;
1799 if (!serializers_registered) {
1800 register_serializers();
1801 serializers_registered = true;
1802 }
1803 EventDeoptimization event;
1804 event.set_compileId(nm->compile_id());
1805 event.set_compiler(nm->compiler_type());
1806 event.set_method(method);
1807 event.set_lineNumber(method->line_number_from_bci(trap_bci));
1808 event.set_bci(trap_bci);
1809 event.set_instruction(instruction);
1810 event.set_reason(reason);
1811 event.set_action(action);
1812 event.commit();
1813 }
1814 }
1815
1816 #endif // INCLUDE_JFR
1817
1818 static void log_deopt(nmethod* nm, Method* tm, intptr_t pc, frame& fr, int trap_bci,
1819 const char* reason_name, const char* reason_action, const char* class_name) {
1820 LogTarget(Debug, deoptimization) lt;
1821 if (lt.is_enabled()) {
1822 LogStream ls(lt);
1823 bool is_osr = nm->is_osr_method();
1824 ls.print("cid=%4d %s level=%d",
1825 nm->compile_id(), (is_osr ? "osr" : " "), nm->comp_level());
1826 ls.print(" %s", tm->name_and_sig_as_C_string());
1827 ls.print(" trap_bci=%d ", trap_bci);
1828 if (is_osr) {
1829 ls.print("osr_bci=%d ", nm->osr_entry_bci());
1830 }
1831 ls.print("%s ", reason_name);
1832 ls.print("%s ", reason_action);
1833 if (class_name != nullptr) {
1834 ls.print("%s ", class_name);
1835 }
1836 ls.print_cr("pc=" INTPTR_FORMAT " relative_pc=" INTPTR_FORMAT,
1837 pc, fr.pc() - nm->code_begin());
1838 }
1839 }
1840
1841 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
1842 HandleMark hm(current);
1843
1844 // uncommon_trap() is called at the beginning of the uncommon trap
1845 // handler. Note this fact before we start generating temporary frames
1846 // that can confuse an asynchronous stack walker. This counter is
1847 // decremented at the end of unpack_frames().
1848
1849 current->inc_in_deopt_handler();
1850
1851 RegisterMap reg_map(current,
1852 RegisterMap::UpdateMap::skip,
1853 RegisterMap::ProcessFrames::include,
1854 RegisterMap::WalkContinuation::skip);
1855 frame stub_frame = current->last_frame();
1856 frame fr = stub_frame.sender(®_map);
1857
1858 // Log a message
1859 Events::log_deopt_message(current, "Uncommon trap: trap_request=" INT32_FORMAT_X_0 " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
1860 trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
1861
1862 {
1863 ResourceMark rm;
1864
1865 DeoptReason reason = trap_request_reason(trap_request);
1866 DeoptAction action = trap_request_action(trap_request);
1867 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1868
1869 vframe* vf = vframe::new_vframe(&fr, ®_map, current);
1870 compiledVFrame* cvf = compiledVFrame::cast(vf);
1871
1872 nmethod* nm = cvf->code();
1873
1874 ScopeDesc* trap_scope = cvf->scope();
1875
1876 bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
1877
1878 if (is_receiver_constraint_failure) {
1879 tty->print_cr(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s", trap_scope->bci(),
1880 p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string());
1881 }
1882
1883 methodHandle trap_method(current, trap_scope->method());
1884 int trap_bci = trap_scope->bci();
1885 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1886 // Record this event in the histogram.
1887 gather_statistics(reason, action, trap_bc);
1888
1889 // Ensure that we can record deopt. history:
1890 bool create_if_missing = ProfileTraps;
1891
1892 methodHandle profiled_method;
1893 profiled_method = trap_method;
1894
1895 MethodData* trap_mdo =
1896 get_method_data(current, profiled_method, create_if_missing);
1897
1898 Symbol* class_name = nullptr;
1899 bool unresolved = false;
1900 if (unloaded_class_index >= 0) {
1901 constantPoolHandle constants (current, trap_method->constants());
1902 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1903 class_name = constants->klass_name_at(unloaded_class_index);
1904 unresolved = true;
1905 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1906 class_name = constants->symbol_at(unloaded_class_index);
1907 }
1908 }
1909 { // Log Deoptimization event for JFR, UL and event system
1910 Method* tm = trap_method();
1911 const char* reason_name = trap_reason_name(reason);
1912 const char* reason_action = trap_action_name(action);
1913 intptr_t pc = p2i(fr.pc());
1914
1915 JFR_ONLY(post_deoptimization_event(nm, tm, trap_bci, trap_bc, reason, action);)
1916
1917 ResourceMark rm;
1918
1919 const char* class_name_str = nullptr;
1920 const char* class_name_msg = nullptr;
1921 stringStream st, stm;
1922 if (class_name != nullptr) {
1923 class_name->print_symbol_on(&st);
1924 class_name_str = st.freeze();
1925 stm.print("class=%s ", class_name_str);
1926 class_name_msg = stm.freeze();
1927 } else {
1928 class_name_msg = "";
1929 }
1930 log_deopt(nm, tm, pc, fr, trap_bci, reason_name, reason_action, class_name_str);
1931 Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s%s",
1932 reason_name, reason_action, pc,
1933 tm->name_and_sig_as_C_string(), trap_bci, class_name_msg, nm->compiler_name());
1934 }
1935
1936 // Print a bunch of diagnostics, if requested.
1937 if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
1938 ResourceMark rm;
1939
1940 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
1941 // We must do this already now, since we cannot acquire this lock while
1942 // holding the tty lock (lock ordering by rank).
1943 ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
1944 (trap_mdo != nullptr),
1945 Mutex::_no_safepoint_check_flag);
1946
1947 ttyLocker ttyl;
1948
1949 char buf[100];
1950 if (xtty != nullptr) {
1951 xtty->begin_head("uncommon_trap thread='%zu' %s",
1952 os::current_thread_id(),
1953 format_trap_request(buf, sizeof(buf), trap_request));
1954 nm->log_identity(xtty);
1955 }
1956 if (class_name != nullptr) {
1957 if (xtty != nullptr) {
1958 if (unresolved) {
1959 xtty->print(" unresolved='1'");
1960 }
1961 xtty->name(class_name);
1962 }
1963 }
1964 if (xtty != nullptr && trap_mdo != nullptr && (int)reason < (int)MethodData::_trap_hist_limit) {
1965 // Dump the relevant MDO state.
1966 // This is the deopt count for the current reason, any previous
1967 // reasons or recompiles seen at this point.
1968 int dcnt = trap_mdo->trap_count(reason);
1969 if (dcnt != 0)
1970 xtty->print(" count='%d'", dcnt);
1971
1972 // We need to lock to read the ProfileData. But to keep the locks ordered, we need to
1973 // lock extra_data_lock before the tty lock.
1974 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1975 int dos = (pdata == nullptr)? 0: pdata->trap_state();
1976 if (dos != 0) {
1977 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1978 if (trap_state_is_recompiled(dos)) {
1979 int recnt2 = trap_mdo->overflow_recompile_count();
1980 if (recnt2 != 0)
1981 xtty->print(" recompiles2='%d'", recnt2);
1982 }
1983 }
1984 }
1985 if (xtty != nullptr) {
1986 xtty->stamp();
1987 xtty->end_head();
1988 }
1989 if (TraceDeoptimization) { // make noise on the tty
1990 stringStream st;
1991 st.print("UNCOMMON TRAP method=%s", trap_scope->method()->name_and_sig_as_C_string());
1992 st.print(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT,
1993 trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin());
1994 st.print(" compiler=%s compile_id=%d", nm->compiler_name(), nm->compile_id());
1995 st.print(" (@" INTPTR_FORMAT ") thread=%zu reason=%s action=%s unloaded_class_index=%d",
1996 p2i(fr.pc()),
1997 os::current_thread_id(),
1998 trap_reason_name(reason),
1999 trap_action_name(action),
2000 unloaded_class_index
2001 );
2002 if (class_name != nullptr) {
2003 st.print(unresolved ? " unresolved class: " : " symbol: ");
2004 class_name->print_symbol_on(&st);
2005 }
2006 st.cr();
2007 tty->print_raw(st.freeze());
2008 }
2009 if (xtty != nullptr) {
2010 // Log the precise location of the trap.
2011 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2012 xtty->begin_elem("jvms bci='%d'", sd->bci());
2013 xtty->method(sd->method());
2014 xtty->end_elem();
2015 if (sd->is_top()) break;
2016 }
2017 xtty->tail("uncommon_trap");
2018 }
2019 }
2020 // (End diagnostic printout.)
2021
2022 if (is_receiver_constraint_failure) {
2023 fatal("missing receiver type check");
2024 }
2025
2026 // Load class if necessary
2027 if (unloaded_class_index >= 0) {
2028 constantPoolHandle constants(current, trap_method->constants());
2029 load_class_by_index(constants, unloaded_class_index, THREAD);
2030 }
2031
2032 // Flush the nmethod if necessary and desirable.
2033 //
2034 // We need to avoid situations where we are re-flushing the nmethod
2035 // because of a hot deoptimization site. Repeated flushes at the same
2036 // point need to be detected by the compiler and avoided. If the compiler
2037 // cannot avoid them (or has a bug and "refuses" to avoid them), this
2038 // module must take measures to avoid an infinite cycle of recompilation
2039 // and deoptimization. There are several such measures:
2040 //
2041 // 1. If a recompilation is ordered a second time at some site X
2042 // and for the same reason R, the action is adjusted to 'reinterpret',
2043 // to give the interpreter time to exercise the method more thoroughly.
2044 // If this happens, the method's overflow_recompile_count is incremented.
2045 //
2046 // 2. If the compiler fails to reduce the deoptimization rate, then
2047 // the method's overflow_recompile_count will begin to exceed the set
2048 // limit PerBytecodeRecompilationCutoff. If this happens, the action
2049 // is adjusted to 'make_not_compilable', and the method is abandoned
2050 // to the interpreter. This is a performance hit for hot methods,
2051 // but is better than a disastrous infinite cycle of recompilations.
2052 // (Actually, only the method containing the site X is abandoned.)
2053 //
2054 // 3. In parallel with the previous measures, if the total number of
2055 // recompilations of a method exceeds the much larger set limit
2056 // PerMethodRecompilationCutoff, the method is abandoned.
2057 // This should only happen if the method is very large and has
2058 // many "lukewarm" deoptimizations. The code which enforces this
2059 // limit is elsewhere (class nmethod, class Method).
2060 //
2061 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2062 // to recompile at each bytecode independently of the per-BCI cutoff.
2063 //
2064 // The decision to update code is up to the compiler, and is encoded
2065 // in the Action_xxx code. If the compiler requests Action_none
2066 // no trap state is changed, no compiled code is changed, and the
2067 // computation suffers along in the interpreter.
2068 //
2069 // The other action codes specify various tactics for decompilation
2070 // and recompilation. Action_maybe_recompile is the loosest, and
2071 // allows the compiled code to stay around until enough traps are seen,
2072 // and until the compiler gets around to recompiling the trapping method.
2073 //
2074 // The other actions cause immediate removal of the present code.
2075
2076 // Traps caused by injected profile shouldn't pollute trap counts.
2077 bool injected_profile_trap = trap_method->has_injected_profile() &&
2078 (reason == Reason_intrinsic || reason == Reason_unreached);
2079
2080 bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2081 bool make_not_entrant = false;
2082 bool make_not_compilable = false;
2083 bool reprofile = false;
2084 switch (action) {
2085 case Action_none:
2086 // Keep the old code.
2087 update_trap_state = false;
2088 break;
2089 case Action_maybe_recompile:
2090 // Do not need to invalidate the present code, but we can
2091 // initiate another
2092 // Start compiler without (necessarily) invalidating the nmethod.
2093 // The system will tolerate the old code, but new code should be
2094 // generated when possible.
2095 break;
2096 case Action_reinterpret:
2097 // Go back into the interpreter for a while, and then consider
2098 // recompiling form scratch.
2099 make_not_entrant = true;
2100 // Reset invocation counter for outer most method.
2101 // This will allow the interpreter to exercise the bytecodes
2102 // for a while before recompiling.
2103 // By contrast, Action_make_not_entrant is immediate.
2104 //
2105 // Note that the compiler will track null_check, null_assert,
2106 // range_check, and class_check events and log them as if they
2107 // had been traps taken from compiled code. This will update
2108 // the MDO trap history so that the next compilation will
2109 // properly detect hot trap sites.
2110 reprofile = true;
2111 break;
2112 case Action_make_not_entrant:
2113 // Request immediate recompilation, and get rid of the old code.
2114 // Make them not entrant, so next time they are called they get
2115 // recompiled. Unloaded classes are loaded now so recompile before next
2116 // time they are called. Same for uninitialized. The interpreter will
2117 // link the missing class, if any.
2118 make_not_entrant = true;
2119 break;
2120 case Action_make_not_compilable:
2121 // Give up on compiling this method at all.
2122 make_not_entrant = true;
2123 make_not_compilable = true;
2124 break;
2125 default:
2126 ShouldNotReachHere();
2127 }
2128
2129 // Setting +ProfileTraps fixes the following, on all platforms:
2130 // The result is infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2131 // recompile relies on a MethodData* to record heroic opt failures.
2132
2133 // Whether the interpreter is producing MDO data or not, we also need
2134 // to use the MDO to detect hot deoptimization points and control
2135 // aggressive optimization.
2136 bool inc_recompile_count = false;
2137
2138 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2139 ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
2140 (trap_mdo != nullptr),
2141 Mutex::_no_safepoint_check_flag);
2142 ProfileData* pdata = nullptr;
2143 if (ProfileTraps && CompilerConfig::is_c2_enabled() && update_trap_state && trap_mdo != nullptr) {
2144 assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2145 uint this_trap_count = 0;
2146 bool maybe_prior_trap = false;
2147 bool maybe_prior_recompile = false;
2148
2149 pdata = query_update_method_data(trap_mdo, trap_bci, reason, nm->method(),
2150 //outputs:
2151 this_trap_count,
2152 maybe_prior_trap,
2153 maybe_prior_recompile);
2154 // Because the interpreter also counts null, div0, range, and class
2155 // checks, these traps from compiled code are double-counted.
2156 // This is harmless; it just means that the PerXTrapLimit values
2157 // are in effect a little smaller than they look.
2158
2159 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2160 if (per_bc_reason != Reason_none) {
2161 // Now take action based on the partially known per-BCI history.
2162 if (maybe_prior_trap
2163 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2164 // If there are too many traps at this BCI, force a recompile.
2165 // This will allow the compiler to see the limit overflow, and
2166 // take corrective action, if possible. The compiler generally
2167 // does not use the exact PerBytecodeTrapLimit value, but instead
2168 // changes its tactics if it sees any traps at all. This provides
2169 // a little hysteresis, delaying a recompile until a trap happens
2170 // several times.
2171 //
2172 // Actually, since there is only one bit of counter per BCI,
2173 // the possible per-BCI counts are {0,1,(per-method count)}.
2174 // This produces accurate results if in fact there is only
2175 // one hot trap site, but begins to get fuzzy if there are
2176 // many sites. For example, if there are ten sites each
2177 // trapping two or more times, they each get the blame for
2178 // all of their traps.
2179 make_not_entrant = true;
2180 }
2181
2182 // Detect repeated recompilation at the same BCI, and enforce a limit.
2183 if (make_not_entrant && maybe_prior_recompile) {
2184 // More than one recompile at this point.
2185 inc_recompile_count = maybe_prior_trap;
2186 }
2187 } else {
2188 // For reasons which are not recorded per-bytecode, we simply
2189 // force recompiles unconditionally.
2190 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2191 make_not_entrant = true;
2192 }
2193
2194 // Go back to the compiler if there are too many traps in this method.
2195 if (this_trap_count >= per_method_trap_limit(reason)) {
2196 // If there are too many traps in this method, force a recompile.
2197 // This will allow the compiler to see the limit overflow, and
2198 // take corrective action, if possible.
2199 // (This condition is an unlikely backstop only, because the
2200 // PerBytecodeTrapLimit is more likely to take effect first,
2201 // if it is applicable.)
2202 make_not_entrant = true;
2203 }
2204
2205 // Here's more hysteresis: If there has been a recompile at
2206 // this trap point already, run the method in the interpreter
2207 // for a while to exercise it more thoroughly.
2208 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2209 reprofile = true;
2210 }
2211 }
2212
2213 // Take requested actions on the method:
2214
2215 // Recompile
2216 if (make_not_entrant) {
2217 if (!nm->make_not_entrant(nmethod::InvalidationReason::UNCOMMON_TRAP)) {
2218 return; // the call did not change nmethod's state
2219 }
2220
2221 if (pdata != nullptr) {
2222 // Record the recompilation event, if any.
2223 int tstate0 = pdata->trap_state();
2224 int tstate1 = trap_state_set_recompiled(tstate0, true);
2225 if (tstate1 != tstate0)
2226 pdata->set_trap_state(tstate1);
2227 }
2228
2229 // For code aging we count traps separately here, using make_not_entrant()
2230 // as a guard against simultaneous deopts in multiple threads.
2231 if (reason == Reason_tenured && trap_mdo != nullptr) {
2232 trap_mdo->inc_tenure_traps();
2233 }
2234 }
2235 if (inc_recompile_count) {
2236 trap_mdo->inc_overflow_recompile_count();
2237 if ((uint)trap_mdo->overflow_recompile_count() >
2238 (uint)PerBytecodeRecompilationCutoff) {
2239 // Give up on the method containing the bad BCI.
2240 if (trap_method() == nm->method()) {
2241 make_not_compilable = true;
2242 } else {
2243 trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2244 // But give grace to the enclosing nm->method().
2245 }
2246 }
2247 }
2248
2249 // Reprofile
2250 if (reprofile) {
2251 CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2252 }
2253
2254 // Give up compiling
2255 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2256 assert(make_not_entrant, "consistent");
2257 nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2258 }
2259
2260 if (ProfileExceptionHandlers && trap_mdo != nullptr) {
2261 BitData* exception_handler_data = trap_mdo->exception_handler_bci_to_data_or_null(trap_bci);
2262 if (exception_handler_data != nullptr) {
2263 // uncommon trap at the start of an exception handler.
2264 // C2 generates these for un-entered exception handlers.
2265 // mark the handler as entered to avoid generating
2266 // another uncommon trap the next time the handler is compiled
2267 exception_handler_data->set_exception_handler_entered();
2268 }
2269 }
2270
2271 } // Free marked resources
2272
2273 }
2274 JRT_END
2275
2276 ProfileData*
2277 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2278 int trap_bci,
2279 Deoptimization::DeoptReason reason,
2280 Method* compiled_method,
2281 //outputs:
2282 uint& ret_this_trap_count,
2283 bool& ret_maybe_prior_trap,
2284 bool& ret_maybe_prior_recompile) {
2285 trap_mdo->check_extra_data_locked();
2286
2287 bool maybe_prior_trap = false;
2288 bool maybe_prior_recompile = false;
2289 uint this_trap_count = 0;
2290 uint idx = reason;
2291 uint prior_trap_count = trap_mdo->trap_count(idx);
2292 this_trap_count = trap_mdo->inc_trap_count(idx);
2293
2294 // If the runtime cannot find a place to store trap history,
2295 // it is estimated based on the general condition of the method.
2296 // If the method has ever been recompiled, or has ever incurred
2297 // a trap with the present reason , then this BCI is assumed
2298 // (pessimistically) to be the culprit.
2299 maybe_prior_trap = (prior_trap_count != 0);
2300 maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2301 ProfileData* pdata = nullptr;
2302
2303
2304 // For reasons which are recorded per bytecode, we check per-BCI data.
2305 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2306 if (per_bc_reason != Reason_none) {
2307 // Find the profile data for this BCI. If there isn't one,
2308 // try to allocate one from the MDO's set of spares.
2309 // This will let us detect a repeated trap at this point.
2310 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : nullptr);
2311
2312 if (pdata != nullptr) {
2313 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2314 if (LogCompilation && xtty != nullptr) {
2315 ttyLocker ttyl;
2316 // no more room for speculative traps in this MDO
2317 xtty->elem("speculative_traps_oom");
2318 }
2319 }
2320 // Query the trap state of this profile datum.
2321 int tstate0 = pdata->trap_state();
2322 if (!trap_state_has_reason(tstate0, per_bc_reason))
2323 maybe_prior_trap = false;
2324 if (!trap_state_is_recompiled(tstate0))
2325 maybe_prior_recompile = false;
2326
2327 // Update the trap state of this profile datum.
2328 int tstate1 = tstate0;
2329 // Record the reason.
2330 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2331 // Store the updated state on the MDO, for next time.
2332 if (tstate1 != tstate0)
2333 pdata->set_trap_state(tstate1);
2334 } else {
2335 if (LogCompilation && xtty != nullptr) {
2336 ttyLocker ttyl;
2337 // Missing MDP? Leave a small complaint in the log.
2338 xtty->elem("missing_mdp bci='%d'", trap_bci);
2339 }
2340 }
2341 }
2342
2343 // Return results:
2344 ret_this_trap_count = this_trap_count;
2345 ret_maybe_prior_trap = maybe_prior_trap;
2346 ret_maybe_prior_recompile = maybe_prior_recompile;
2347 return pdata;
2348 }
2349
2350 void
2351 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2352 ResourceMark rm;
2353 // Ignored outputs:
2354 uint ignore_this_trap_count;
2355 bool ignore_maybe_prior_trap;
2356 bool ignore_maybe_prior_recompile;
2357 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2358
2359 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2360 MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2361
2362 query_update_method_data(trap_mdo, trap_bci,
2363 (DeoptReason)reason,
2364 nullptr,
2365 ignore_this_trap_count,
2366 ignore_maybe_prior_trap,
2367 ignore_maybe_prior_recompile);
2368 }
2369
2370 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode) {
2371 // Enable WXWrite: current function is called from methods compiled by C2 directly
2372 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2373
2374 // Still in Java no safepoints
2375 {
2376 // This enters VM and may safepoint
2377 uncommon_trap_inner(current, trap_request);
2378 }
2379 HandleMark hm(current);
2380 return fetch_unroll_info_helper(current, exec_mode);
2381 }
2382
2383 // Local derived constants.
2384 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2385 const int DS_REASON_MASK = ((uint)DataLayout::trap_mask) >> 1;
2386 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2387
2388 //---------------------------trap_state_reason---------------------------------
2389 Deoptimization::DeoptReason
2390 Deoptimization::trap_state_reason(int trap_state) {
2391 // This assert provides the link between the width of DataLayout::trap_bits
2392 // and the encoding of "recorded" reasons. It ensures there are enough
2393 // bits to store all needed reasons in the per-BCI MDO profile.
2394 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2395 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2396 trap_state -= recompile_bit;
2397 if (trap_state == DS_REASON_MASK) {
2398 return Reason_many;
2399 } else {
2400 assert((int)Reason_none == 0, "state=0 => Reason_none");
2401 return (DeoptReason)trap_state;
2402 }
2403 }
2404 //-------------------------trap_state_has_reason-------------------------------
2405 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2406 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2407 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2408 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2409 trap_state -= recompile_bit;
2410 if (trap_state == DS_REASON_MASK) {
2411 return -1; // true, unspecifically (bottom of state lattice)
2412 } else if (trap_state == reason) {
2413 return 1; // true, definitely
2414 } else if (trap_state == 0) {
2415 return 0; // false, definitely (top of state lattice)
2416 } else {
2417 return 0; // false, definitely
2418 }
2419 }
2420 //-------------------------trap_state_add_reason-------------------------------
2421 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2422 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2423 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2424 trap_state -= recompile_bit;
2425 if (trap_state == DS_REASON_MASK) {
2426 return trap_state + recompile_bit; // already at state lattice bottom
2427 } else if (trap_state == reason) {
2428 return trap_state + recompile_bit; // the condition is already true
2429 } else if (trap_state == 0) {
2430 return reason + recompile_bit; // no condition has yet been true
2431 } else {
2432 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
2433 }
2434 }
2435 //-----------------------trap_state_is_recompiled------------------------------
2436 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2437 return (trap_state & DS_RECOMPILE_BIT) != 0;
2438 }
2439 //-----------------------trap_state_set_recompiled-----------------------------
2440 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2441 if (z) return trap_state | DS_RECOMPILE_BIT;
2442 else return trap_state & ~DS_RECOMPILE_BIT;
2443 }
2444 //---------------------------format_trap_state---------------------------------
2445 // This is used for debugging and diagnostics, including LogFile output.
2446 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2447 int trap_state) {
2448 assert(buflen > 0, "sanity");
2449 DeoptReason reason = trap_state_reason(trap_state);
2450 bool recomp_flag = trap_state_is_recompiled(trap_state);
2451 // Re-encode the state from its decoded components.
2452 int decoded_state = 0;
2453 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2454 decoded_state = trap_state_add_reason(decoded_state, reason);
2455 if (recomp_flag)
2456 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2457 // If the state re-encodes properly, format it symbolically.
2458 // Because this routine is used for debugging and diagnostics,
2459 // be robust even if the state is a strange value.
2460 size_t len;
2461 if (decoded_state != trap_state) {
2462 // Random buggy state that doesn't decode??
2463 len = jio_snprintf(buf, buflen, "#%d", trap_state);
2464 } else {
2465 len = jio_snprintf(buf, buflen, "%s%s",
2466 trap_reason_name(reason),
2467 recomp_flag ? " recompiled" : "");
2468 }
2469 return buf;
2470 }
2471
2472
2473 //--------------------------------statics--------------------------------------
2474 const char* Deoptimization::_trap_reason_name[] = {
2475 // Note: Keep this in sync. with enum DeoptReason.
2476 "none",
2477 "null_check",
2478 "null_assert",
2479 "range_check",
2480 "class_check",
2481 "array_check",
2482 "intrinsic",
2483 "bimorphic",
2484 "profile_predicate",
2485 "auto_vectorization_check",
2486 "unloaded",
2487 "uninitialized",
2488 "initialized",
2489 "unreached",
2490 "unhandled",
2491 "constraint",
2492 "div0_check",
2493 "age",
2494 "predicate",
2495 "loop_limit_check",
2496 "speculate_class_check",
2497 "speculate_null_check",
2498 "speculate_null_assert",
2499 "unstable_if",
2500 "unstable_fused_if",
2501 "receiver_constraint",
2502 "not_compiled_exception_handler",
2503 "short_running_loop",
2504 "tenured"
2505 };
2506 const char* Deoptimization::_trap_action_name[] = {
2507 // Note: Keep this in sync. with enum DeoptAction.
2508 "none",
2509 "maybe_recompile",
2510 "reinterpret",
2511 "make_not_entrant",
2512 "make_not_compilable"
2513 };
2514
2515 const char* Deoptimization::trap_reason_name(int reason) {
2516 // Check that every reason has a name
2517 STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2518
2519 if (reason == Reason_many) return "many";
2520 if ((uint)reason < Reason_LIMIT)
2521 return _trap_reason_name[reason];
2522 static char buf[20];
2523 os::snprintf_checked(buf, sizeof(buf), "reason%d", reason);
2524 return buf;
2525 }
2526 const char* Deoptimization::trap_action_name(int action) {
2527 // Check that every action has a name
2528 STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2529
2530 if ((uint)action < Action_LIMIT)
2531 return _trap_action_name[action];
2532 static char buf[20];
2533 os::snprintf_checked(buf, sizeof(buf), "action%d", action);
2534 return buf;
2535 }
2536
2537 // This is used for debugging and diagnostics, including LogFile output.
2538 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2539 int trap_request) {
2540 jint unloaded_class_index = trap_request_index(trap_request);
2541 const char* reason = trap_reason_name(trap_request_reason(trap_request));
2542 const char* action = trap_action_name(trap_request_action(trap_request));
2543 size_t len;
2544 if (unloaded_class_index < 0) {
2545 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'", reason, action);
2546 } else {
2547 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
2548 reason, action, unloaded_class_index);
2549 }
2550 return buf;
2551 }
2552
2553 juint Deoptimization::_deoptimization_hist
2554 [Deoptimization::Reason_LIMIT]
2555 [1 + Deoptimization::Action_LIMIT]
2556 [Deoptimization::BC_CASE_LIMIT]
2557 = {0};
2558
2559 enum {
2560 LSB_BITS = 8,
2561 LSB_MASK = right_n_bits(LSB_BITS)
2562 };
2563
2564 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2565 Bytecodes::Code bc) {
2566 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2567 assert(action >= 0 && action < Action_LIMIT, "oob");
2568 _deoptimization_hist[Reason_none][0][0] += 1; // total
2569 _deoptimization_hist[reason][0][0] += 1; // per-reason total
2570 juint* cases = _deoptimization_hist[reason][1+action];
2571 juint* bc_counter_addr = nullptr;
2572 juint bc_counter = 0;
2573 // Look for an unused counter, or an exact match to this BC.
2574 if (bc != Bytecodes::_illegal) {
2575 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2576 juint* counter_addr = &cases[bc_case];
2577 juint counter = *counter_addr;
2578 if ((counter == 0 && bc_counter_addr == nullptr)
2579 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2580 // this counter is either free or is already devoted to this BC
2581 bc_counter_addr = counter_addr;
2582 bc_counter = counter | bc;
2583 }
2584 }
2585 }
2586 if (bc_counter_addr == nullptr) {
2587 // Overflow, or no given bytecode.
2588 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2589 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
2590 }
2591 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2592 }
2593
2594 jint Deoptimization::total_deoptimization_count() {
2595 return _deoptimization_hist[Reason_none][0][0];
2596 }
2597
2598 // Get the deopt count for a specific reason and a specific action. If either
2599 // one of 'reason' or 'action' is null, the method returns the sum of all
2600 // deoptimizations with the specific 'action' or 'reason' respectively.
2601 // If both arguments are null, the method returns the total deopt count.
2602 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2603 if (reason_str == nullptr && action_str == nullptr) {
2604 return total_deoptimization_count();
2605 }
2606 juint counter = 0;
2607 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2608 if (reason_str == nullptr || !strcmp(reason_str, trap_reason_name(reason))) {
2609 for (int action = 0; action < Action_LIMIT; action++) {
2610 if (action_str == nullptr || !strcmp(action_str, trap_action_name(action))) {
2611 juint* cases = _deoptimization_hist[reason][1+action];
2612 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2613 counter += cases[bc_case] >> LSB_BITS;
2614 }
2615 }
2616 }
2617 }
2618 }
2619 return counter;
2620 }
2621
2622 void Deoptimization::print_statistics() {
2623 juint total = total_deoptimization_count();
2624 juint account = total;
2625 if (total != 0) {
2626 ttyLocker ttyl;
2627 if (xtty != nullptr) xtty->head("statistics type='deoptimization'");
2628 tty->print_cr("Deoptimization traps recorded:");
2629 #define PRINT_STAT_LINE(name, r) \
2630 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2631 PRINT_STAT_LINE("total", total);
2632 // For each non-zero entry in the histogram, print the reason,
2633 // the action, and (if specifically known) the type of bytecode.
2634 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2635 for (int action = 0; action < Action_LIMIT; action++) {
2636 juint* cases = _deoptimization_hist[reason][1+action];
2637 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2638 juint counter = cases[bc_case];
2639 if (counter != 0) {
2640 char name[1*K];
2641 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2642 os::snprintf_checked(name, sizeof(name), "%s/%s/%s",
2643 trap_reason_name(reason),
2644 trap_action_name(action),
2645 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2646 juint r = counter >> LSB_BITS;
2647 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2648 account -= r;
2649 }
2650 }
2651 }
2652 }
2653 if (account != 0) {
2654 PRINT_STAT_LINE("unaccounted", account);
2655 }
2656 #undef PRINT_STAT_LINE
2657 if (xtty != nullptr) xtty->tail("statistics");
2658 }
2659 }
2660
2661 #else // COMPILER2
2662
2663 // Stubs for C1 only system.
2664 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2665 return false;
2666 }
2667
2668 const char* Deoptimization::trap_reason_name(int reason) {
2669 return "unknown";
2670 }
2671
2672 jint Deoptimization::total_deoptimization_count() {
2673 return 0;
2674 }
2675
2676 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2677 return 0;
2678 }
2679
2680 void Deoptimization::print_statistics() {
2681 // no output
2682 }
2683
2684 void
2685 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2686 // no update
2687 }
2688
2689 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2690 return 0;
2691 }
2692
2693 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2694 Bytecodes::Code bc) {
2695 // no update
2696 }
2697
2698 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2699 int trap_state) {
2700 jio_snprintf(buf, buflen, "#%d", trap_state);
2701 return buf;
2702 }
2703
2704 #endif // COMPILER2