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