1 /*
2 * Copyright (c) 1997, 2025, 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 nmethod::DeoptimizationStatus status =
136 inc_recompile_counts ? nmethod::deoptimize : nmethod::deoptimize_noupdate;
137 AtomicAccess::store(&nm->_deoptimization_status, status);
138
139 // Make sure active is not committed
140 assert(DeoptimizationScope::_committed_deopt_gen < DeoptimizationScope::_active_deopt_gen, "Must be");
141 assert(nm->_deoptimization_generation == 0, "Is already marked");
142
143 nm->_deoptimization_generation = DeoptimizationScope::_active_deopt_gen;
144 _required_gen = DeoptimizationScope::_active_deopt_gen;
145 }
146
147 void DeoptimizationScope::dependent(nmethod* nm) {
148 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
149
150 // A method marked by someone else may have a _required_gen lower than what we marked with.
151 // Therefore only store it if it's higher than _required_gen.
152 if (_required_gen < nm->_deoptimization_generation) {
153 _required_gen = nm->_deoptimization_generation;
154 }
155 }
156
157 void DeoptimizationScope::deoptimize_marked() {
158 assert(!_deopted, "Already deopted");
159
160 // We are not alive yet.
161 if (!Universe::is_fully_initialized()) {
162 DEBUG_ONLY(_deopted = true;)
163 return;
164 }
165
166 // Safepoints are a special case, handled here.
167 if (SafepointSynchronize::is_at_safepoint()) {
168 DeoptimizationScope::_committed_deopt_gen = DeoptimizationScope::_active_deopt_gen;
169 DeoptimizationScope::_active_deopt_gen++;
170 Deoptimization::deoptimize_all_marked();
171 DEBUG_ONLY(_deopted = true;)
172 return;
173 }
174
175 uint64_t comitting = 0;
176 bool wait = false;
177 while (true) {
178 {
179 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
180
181 // First we check if we or someone else already deopted the gen we want.
182 if (DeoptimizationScope::_committed_deopt_gen >= _required_gen) {
183 DEBUG_ONLY(_deopted = true;)
184 return;
185 }
186 if (!_committing_in_progress) {
187 // The version we are about to commit.
188 comitting = DeoptimizationScope::_active_deopt_gen;
189 // Make sure new marks use a higher gen.
190 DeoptimizationScope::_active_deopt_gen++;
191 _committing_in_progress = true;
192 wait = false;
193 } else {
194 // Another thread is handshaking and committing a gen.
195 wait = true;
196 }
197 }
198 if (wait) {
199 // Wait and let the concurrent handshake be performed.
200 ThreadBlockInVM tbivm(JavaThread::current());
201 os::naked_yield();
202 } else {
203 // Performs the handshake.
204 Deoptimization::deoptimize_all_marked(); // May safepoint and an additional deopt may have occurred.
205 DEBUG_ONLY(_deopted = true;)
206 {
207 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
208
209 // Make sure that committed doesn't go backwards.
210 // Should only happen if we did a deopt during a safepoint above.
211 if (DeoptimizationScope::_committed_deopt_gen < comitting) {
212 DeoptimizationScope::_committed_deopt_gen = comitting;
213 }
214 _committing_in_progress = false;
215
216 assert(DeoptimizationScope::_committed_deopt_gen >= _required_gen, "Must be");
217
218 return;
219 }
220 }
221 }
222 }
223
224 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
225 int caller_adjustment,
226 int caller_actual_parameters,
227 int number_of_frames,
228 intptr_t* frame_sizes,
229 address* frame_pcs,
230 BasicType return_type,
231 int exec_mode) {
232 _size_of_deoptimized_frame = size_of_deoptimized_frame;
233 _caller_adjustment = caller_adjustment;
234 _caller_actual_parameters = caller_actual_parameters;
235 _number_of_frames = number_of_frames;
236 _frame_sizes = frame_sizes;
237 _frame_pcs = frame_pcs;
238 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
239 _return_type = return_type;
240 _initial_info = 0;
241 // PD (x86 only)
242 _counter_temp = 0;
243 _unpack_kind = exec_mode;
244 _sender_sp_temp = 0;
245
246 _total_frame_sizes = size_of_frames();
247 assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
248 }
249
250 Deoptimization::UnrollBlock::~UnrollBlock() {
251 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
252 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
253 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
254 }
255
256 int Deoptimization::UnrollBlock::size_of_frames() const {
257 // Account first for the adjustment of the initial frame
258 intptr_t result = _caller_adjustment;
259 for (int index = 0; index < number_of_frames(); index++) {
260 result += frame_sizes()[index];
261 }
262 return checked_cast<int>(result);
263 }
264
265 void Deoptimization::UnrollBlock::print() {
266 ResourceMark rm;
267 stringStream st;
268 st.print_cr("UnrollBlock");
269 st.print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
270 st.print( " frame_sizes: ");
271 for (int index = 0; index < number_of_frames(); index++) {
272 st.print("%zd ", frame_sizes()[index]);
273 }
274 st.cr();
275 tty->print_raw(st.freeze());
276 }
277
278 // In order to make fetch_unroll_info work properly with escape
279 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
280 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
281 // which is called from the method fetch_unroll_info_helper below.
282 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
283 // fetch_unroll_info() is called at the beginning of the deoptimization
284 // handler. Note this fact before we start generating temporary frames
285 // that can confuse an asynchronous stack walker. This counter is
286 // decremented at the end of unpack_frames().
287 current->inc_in_deopt_handler();
288
289 if (exec_mode == Unpack_exception) {
290 // When we get here, a callee has thrown an exception into a deoptimized
291 // frame. That throw might have deferred stack watermark checking until
292 // after unwinding. So we deal with such deferred requests here.
293 StackWatermarkSet::after_unwind(current);
294 }
295
296 return fetch_unroll_info_helper(current, exec_mode);
297 JRT_END
298
299 #if COMPILER2_OR_JVMCI
300 // print information about reallocated objects
301 static void print_objects(JavaThread* deoptee_thread, 302 GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
303 ResourceMark rm;
304 stringStream st; // change to logStream with logging
305 st.print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
306 fieldDescriptor fd;
307
308 for (int i = 0; i < objects->length(); i++) {
309 ObjectValue* sv = (ObjectValue*) objects->at(i);
310 Handle obj = sv->value();
311
312 if (obj.is_null()) {
313 st.print_cr(" nullptr");
314 continue;
315 }
316
317 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
318
319 st.print(" object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
320 k->print_value_on(&st);
321 st.print_cr(" allocated (%zu bytes)", obj->size() * HeapWordSize);
322
323 if (Verbose && k != nullptr) {
324 k->oop_print_on(obj(), &st);
325 }
326 }
327 tty->print_raw(st.freeze());
328 }
329
330 static bool rematerialize_objects(JavaThread* thread, int exec_mode, nmethod* compiled_method,
331 frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
332 bool& deoptimized_objects) {
333 bool realloc_failures = false;
334 assert (chunk->at(0)->scope() != nullptr,"expect only compiled java frames");
335
336 JavaThread* deoptee_thread = chunk->at(0)->thread();
337 assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
338 "a frame can only be deoptimized by the owner thread");
339
340 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects_to_rematerialize(deoptee, map);
341
342 // The flag return_oop() indicates call sites which return oop
343 // in compiled code. Such sites include java method calls,
344 // runtime calls (for example, used to allocate new objects/arrays
345 // on slow code path) and any other calls generated in compiled code.
346 // It is not guaranteed that we can get such information here only
347 // by analyzing bytecode in deoptimized frames. This is why this flag
348 // is set during method compilation (see Compile::Process_OopMap_Node()).
349 // If the previous frame was popped or if we are dispatching an exception,
350 // we don't have an oop result.
351 bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt); 352 Handle return_value;
353 if (save_oop_result) {
354 // Reallocation may trigger GC. If deoptimization happened on return from
355 // call which returns oop we need to save it since it is not in oopmap.
356 oop result = deoptee.saved_oop_result(&map);
357 assert(oopDesc::is_oop_or_null(result), "must be oop");
358 return_value = Handle(thread, result);
359 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
360 if (TraceDeoptimization) {
361 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
362 tty->cr();
363 }
364 }
365 if (objects != nullptr) {
366 if (exec_mode == Deoptimization::Unpack_none) {
367 assert(thread->thread_state() == _thread_in_vm, "assumption");
368 JavaThread* THREAD = thread; // For exception macros.
369 // Clear pending OOM if reallocation fails and return true indicating allocation failure
370 realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
371 deoptimized_objects = true;
372 } else {
373 JavaThread* current = thread; // For JRT_BLOCK
374 JRT_BLOCK
375 realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
376 JRT_END
377 }
378 guarantee(compiled_method != nullptr, "deopt must be associated with an nmethod"); 379 bool is_jvmci = compiled_method->is_compiled_by_jvmci(); 380 Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, is_jvmci); 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 bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
454
455 // Reallocate the non-escaping objects and restore their fields.
456 if (jvmci_enabled COMPILER2_PRESENT(|| (DoEscapeAnalysis && EliminateAllocations)
457 || EliminateAutoBox || EnableVectorAggressiveReboxing)) {
458 realloc_failures = rematerialize_objects(thread, Unpack_none, nm, deoptee, map, chunk, deoptimized_objects);
459 }
460
461 // MonitorInfo structures used in eliminate_locks are not GC safe.
462 NoSafepointVerifier no_safepoint;
463
464 // Now relock objects if synchronization on them was eliminated.
465 if (jvmci_enabled COMPILER2_PRESENT(|| ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks))) {
466 restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
467 }
468 return deoptimized_objects;
469 }
470 #endif // COMPILER2_OR_JVMCI
471
472 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
473 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
474 JFR_ONLY(Jfr::check_and_process_sample_request(current);)
475 // When we get here we are about to unwind the deoptee frame. In order to
476 // catch not yet safe to use frames, the following stack watermark barrier
477 // poll will make such frames safe to use.
478 StackWatermarkSet::before_unwind(current);
479
480 // Note: there is a safepoint safety issue here. No matter whether we enter
481 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
482 // the vframeArray is created.
483 //
484
485 // Allocate our special deoptimization ResourceMark
486 DeoptResourceMark* dmark = new DeoptResourceMark(current);
487 assert(current->deopt_mark() == nullptr, "Pending deopt!");
488 current->set_deopt_mark(dmark);
489
490 frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
491 RegisterMap map(current,
492 RegisterMap::UpdateMap::include,
493 RegisterMap::ProcessFrames::include,
494 RegisterMap::WalkContinuation::skip);
495 RegisterMap dummy_map(current,
496 RegisterMap::UpdateMap::skip,
497 RegisterMap::ProcessFrames::include,
498 RegisterMap::WalkContinuation::skip);
499 // Now get the deoptee with a valid map
500 frame deoptee = stub_frame.sender(&map);
501 if (exec_mode == Unpack_deopt) {
502 assert(deoptee.is_deoptimized_frame(), "frame is not marked for deoptimization");
503 }
504 // Set the deoptee nmethod
505 assert(current->deopt_compiled_method() == nullptr, "Pending deopt!");
506 nmethod* nm = deoptee.cb()->as_nmethod_or_null();
507 current->set_deopt_compiled_method(nm);
508
509 if (VerifyStack) {
510 current->validate_frame_layout();
511 }
512
513 // Create a growable array of VFrames where each VFrame represents an inlined
514 // Java frame. This storage is allocated with the usual system arena.
515 assert(deoptee.is_compiled_frame(), "Wrong frame type");
516 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
517 vframe* vf = vframe::new_vframe(&deoptee, &map, current);
518 while (!vf->is_top()) {
519 assert(vf->is_compiled_frame(), "Wrong frame type");
520 chunk->push(compiledVFrame::cast(vf));
521 vf = vf->sender();
522 }
523 assert(vf->is_compiled_frame(), "Wrong frame type");
524 chunk->push(compiledVFrame::cast(vf));
525
526 bool realloc_failures = false;
527
528 #if COMPILER2_OR_JVMCI
529 bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
530
531 // Reallocate the non-escaping objects and restore their fields. Then
532 // relock objects if synchronization on them was eliminated.
533 if (jvmci_enabled COMPILER2_PRESENT( || (DoEscapeAnalysis && EliminateAllocations)
534 || EliminateAutoBox || EnableVectorAggressiveReboxing )) {
535 bool unused;
536 realloc_failures = rematerialize_objects(current, exec_mode, nm, deoptee, map, chunk, unused);
537 }
538 #endif // COMPILER2_OR_JVMCI
539
540 // Ensure that no safepoint is taken after pointers have been stored
541 // in fields of rematerialized objects. If a safepoint occurs from here on
542 // out the java state residing in the vframeArray will be missed.
543 // Locks may be rebaised in a safepoint.
544 NoSafepointVerifier no_safepoint;
545
546 #if COMPILER2_OR_JVMCI
547 if ((jvmci_enabled COMPILER2_PRESENT( || ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) ))
548 && !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
549 bool unused = false;
550 restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
551 }
552 #endif // COMPILER2_OR_JVMCI
553
554 ScopeDesc* trap_scope = chunk->at(0)->scope();
555 Handle exceptionObject;
556 if (trap_scope->rethrow_exception()) {
557 #ifndef PRODUCT
558 if (PrintDeoptimizationDetails) {
559 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());
560 }
561 #endif // !PRODUCT
562
563 GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
564 guarantee(expressions != nullptr && expressions->length() == 1, "should have only exception on stack");
565 guarantee(exec_mode != Unpack_exception, "rethrow_exception set with Unpack_exception");
566 ScopeValue* topOfStack = expressions->top();
567 exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
568 guarantee(exceptionObject() != nullptr, "exception oop can not be null");
569 }
570
571 vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
572 #if COMPILER2_OR_JVMCI
573 if (realloc_failures) {
574 // This destroys all ScopedValue bindings.
575 current->clear_scopedValueBindings();
576 pop_frames_failed_reallocs(current, array);
577 }
578 #endif
579
580 assert(current->vframe_array_head() == nullptr, "Pending deopt!");
581 current->set_vframe_array_head(array);
582
583 // Now that the vframeArray has been created if we have any deferred local writes
584 // added by jvmti then we can free up that structure as the data is now in the
585 // vframeArray
586
587 JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
588
589 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
590 CodeBlob* cb = stub_frame.cb();
591 // Verify we have the right vframeArray
592 assert(cb->frame_size() >= 0, "Unexpected frame size");
593 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
594 assert(unpack_sp == deoptee.unextended_sp(), "must be");
595
596 #ifdef ASSERT
597 assert(cb->is_deoptimization_stub() ||
598 cb->is_uncommon_trap_stub() ||
599 strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
600 strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
601 "unexpected code blob: %s", cb->name());
602 #endif
603
604 // This is a guarantee instead of an assert because if vframe doesn't match
605 // we will unpack the wrong deoptimized frame and wind up in strange places
606 // where it will be very difficult to figure out what went wrong. Better
607 // to die an early death here than some very obscure death later when the
608 // trail is cold.
609 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
610
611 int number_of_frames = array->frames();
612
613 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
614 // virtual activation, which is the reverse of the elements in the vframes array.
615 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
616 // +1 because we always have an interpreter return address for the final slot.
617 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
618 int popframe_extra_args = 0;
619 // Create an interpreter return address for the stub to use as its return
620 // address so the skeletal frames are perfectly walkable
621 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
622
623 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
624 // activation be put back on the expression stack of the caller for reexecution
625 if (JvmtiExport::can_pop_frame() && current->popframe_forcing_deopt_reexecution()) {
626 popframe_extra_args = in_words(current->popframe_preserved_args_size_in_words());
627 }
628
629 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
630 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
631 // than simply use array->sender.pc(). This requires us to walk the current set of frames
632 //
633 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
634 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
635
636 // It's possible that the number of parameters at the call site is
637 // different than number of arguments in the callee when method
638 // handles are used. If the caller is interpreted get the real
639 // value so that the proper amount of space can be added to it's
640 // frame.
641 bool caller_was_method_handle = false;
642 if (deopt_sender.is_interpreted_frame()) {
643 methodHandle method(current, deopt_sender.interpreter_frame_method());
644 Bytecode_invoke cur(method, deopt_sender.interpreter_frame_bci());
645 if (cur.has_member_arg()) {
646 // This should cover all real-world cases. One exception is a pathological chain of
647 // MH.linkToXXX() linker calls, which only trusted code could do anyway. To handle that case, we
648 // would need to get the size from the resolved method entry. Another exception would
649 // be an invokedynamic with an adapter that is really a MethodHandle linker.
650 caller_was_method_handle = true;
651 }
652 }
653
654 //
655 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
656 // frame_sizes/frame_pcs[1] next oldest frame (int)
657 // frame_sizes/frame_pcs[n] youngest frame (int)
658 //
659 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
660 // owns the space for the return address to it's caller). Confusing ain't it.
661 //
662 // The vframe array can address vframes with indices running from
663 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
664 // When we create the skeletal frames we need the oldest frame to be in the zero slot
665 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
666 // so things look a little strange in this loop.
667 //
668 int callee_parameters = 0;
669 int callee_locals = 0;
670 for (int index = 0; index < array->frames(); index++ ) {
671 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
672 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
673 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
674 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
675 callee_locals,
676 index == 0,
677 popframe_extra_args);
678 // This pc doesn't have to be perfect just good enough to identify the frame
679 // as interpreted so the skeleton frame will be walkable
680 // The correct pc will be set when the skeleton frame is completely filled out
681 // The final pc we store in the loop is wrong and will be overwritten below
682 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
683
684 callee_parameters = array->element(index)->method()->size_of_parameters();
685 callee_locals = array->element(index)->method()->max_locals();
686 popframe_extra_args = 0;
687 }
688
689 // Compute whether the root vframe returns a float or double value.
690 BasicType return_type;
691 {
692 methodHandle method(current, array->element(0)->method());
693 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
694 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
695 }
696
697 // Compute information for handling adapters and adjusting the frame size of the caller.
698 int caller_adjustment = 0;
699
700 // Compute the amount the oldest interpreter frame will have to adjust
701 // its caller's stack by. If the caller is a compiled frame then
702 // we pretend that the callee has no parameters so that the
703 // extension counts for the full amount of locals and not just
704 // locals-parms. This is because without a c2i adapter the parm
705 // area as created by the compiled frame will not be usable by
706 // the interpreter. (Depending on the calling convention there
707 // may not even be enough space).
708
709 // QQQ I'd rather see this pushed down into last_frame_adjust
710 // and have it take the sender (aka caller).
711
712 if (!deopt_sender.is_interpreted_frame() || caller_was_method_handle) {
713 caller_adjustment = last_frame_adjust(0, callee_locals);
714 } else if (callee_locals > callee_parameters) {
715 // The caller frame may need extending to accommodate
716 // non-parameter locals of the first unpacked interpreted frame.
717 // Compute that adjustment.
718 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
719 }
720
721 // If the sender is deoptimized the we must retrieve the address of the handler
722 // since the frame will "magically" show the original pc before the deopt
723 // and we'd undo the deopt.
724
725 frame_pcs[0] = Continuation::is_cont_barrier_frame(deoptee) ? StubRoutines::cont_returnBarrier() : deopt_sender.raw_pc();
726 if (Continuation::is_continuation_enterSpecial(deopt_sender)) {
727 ContinuationEntry::from_frame(deopt_sender)->set_argsize(0);
728 }
729
730 assert(CodeCache::find_blob(frame_pcs[0]) != nullptr, "bad pc");
731
732 #if INCLUDE_JVMCI
733 if (exceptionObject() != nullptr) {
734 current->set_exception_oop(exceptionObject());
735 exec_mode = Unpack_exception;
736 assert(array->element(0)->rethrow_exception(), "must be");
737 }
738 #endif
739
740 if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
741 assert(current->has_pending_exception(), "should have thrown OOME");
742 current->set_exception_oop(current->pending_exception());
743 current->clear_pending_exception();
744 exec_mode = Unpack_exception;
745 }
746
747 #if INCLUDE_JVMCI
748 if (current->frames_to_pop_failed_realloc() > 0) {
749 current->set_pending_monitorenter(false);
750 }
751 #endif
752
753 int caller_actual_parameters = -1; // value not used except for interpreted frames, see below
754 if (deopt_sender.is_interpreted_frame()) {
755 caller_actual_parameters = callee_parameters + (caller_was_method_handle ? 1 : 0);
756 }
757
758 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
759 caller_adjustment * BytesPerWord,
760 caller_actual_parameters,
761 number_of_frames,
762 frame_sizes,
763 frame_pcs,
764 return_type,
765 exec_mode);
766 // On some platforms, we need a way to pass some platform dependent
767 // information to the unpacking code so the skeletal frames come out
768 // correct (initial fp value, unextended sp, ...)
769 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
770
771 if (array->frames() > 1) {
772 if (VerifyStack && TraceDeoptimization) {
773 tty->print_cr("Deoptimizing method containing inlining");
774 }
775 }
776
777 array->set_unroll_block(info);
778 return info;
779 }
780
781 // Called to cleanup deoptimization data structures in normal case
782 // after unpacking to stack and when stack overflow error occurs
783 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
784 vframeArray *array) {
785
786 // Get array if coming from exception
787 if (array == nullptr) {
788 array = thread->vframe_array_head();
789 }
790 thread->set_vframe_array_head(nullptr);
791
792 // Free the previous UnrollBlock
793 vframeArray* old_array = thread->vframe_array_last();
794 thread->set_vframe_array_last(array);
795
796 if (old_array != nullptr) {
797 UnrollBlock* old_info = old_array->unroll_block();
798 old_array->set_unroll_block(nullptr);
799 delete old_info;
800 delete old_array;
801 }
802
803 // Deallocate any resource creating in this routine and any ResourceObjs allocated
804 // inside the vframeArray (StackValueCollections)
805
806 delete thread->deopt_mark();
807 thread->set_deopt_mark(nullptr);
808 thread->set_deopt_compiled_method(nullptr);
809
810
811 if (JvmtiExport::can_pop_frame()) {
812 // Regardless of whether we entered this routine with the pending
813 // popframe condition bit set, we should always clear it now
814 thread->clear_popframe_condition();
815 }
816
817 // unpack_frames() is called at the end of the deoptimization handler
818 // and (in C2) at the end of the uncommon trap handler. Note this fact
819 // so that an asynchronous stack walker can work again. This counter is
820 // incremented at the beginning of fetch_unroll_info() and (in C2) at
821 // the beginning of uncommon_trap().
822 thread->dec_in_deopt_handler();
823 }
824
825 // Moved from cpu directories because none of the cpus has callee save values.
826 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
827 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
828
829 // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
830 // the days we had adapter frames. When we deoptimize a situation where a
831 // compiled caller calls a compiled caller will have registers it expects
832 // to survive the call to the callee. If we deoptimize the callee the only
833 // way we can restore these registers is to have the oldest interpreter
834 // frame that we create restore these values. That is what this routine
835 // will accomplish.
836
837 // At the moment we have modified c2 to not have any callee save registers
838 // so this problem does not exist and this routine is just a place holder.
839
840 assert(f->is_interpreted_frame(), "must be interpreted");
841 }
842
843 #ifndef PRODUCT
844 #ifdef ASSERT
845 // Return true if the execution after the provided bytecode continues at the
846 // next bytecode in the code. This is not the case for gotos, returns, and
847 // throws.
848 static bool falls_through(Bytecodes::Code bc) {
849 switch (bc) {
850 case Bytecodes::_goto:
851 case Bytecodes::_goto_w:
852 case Bytecodes::_athrow:
853 case Bytecodes::_areturn:
854 case Bytecodes::_dreturn:
855 case Bytecodes::_freturn:
856 case Bytecodes::_ireturn:
857 case Bytecodes::_lreturn:
858 case Bytecodes::_jsr:
859 case Bytecodes::_ret:
860 case Bytecodes::_return:
861 case Bytecodes::_lookupswitch:
862 case Bytecodes::_tableswitch:
863 return false;
864 default:
865 return true;
866 }
867 }
868 #endif
869 #endif
870
871 // Return BasicType of value being returned
872 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
873 assert(thread == JavaThread::current(), "pre-condition");
874
875 // We are already active in the special DeoptResourceMark any ResourceObj's we
876 // allocate will be freed at the end of the routine.
877
878 // JRT_LEAF methods don't normally allocate handles and there is a
879 // NoHandleMark to enforce that. It is actually safe to use Handles
880 // in a JRT_LEAF method, and sometimes desirable, but to do so we
881 // must use ResetNoHandleMark to bypass the NoHandleMark, and
882 // then use a HandleMark to ensure any Handles we do create are
883 // cleaned up in this scope.
884 ResetNoHandleMark rnhm;
885 HandleMark hm(thread);
886
887 frame stub_frame = thread->last_frame();
888
889 Continuation::notify_deopt(thread, stub_frame.sp());
890
891 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
892 // must point to the vframeArray for the unpack frame.
893 vframeArray* array = thread->vframe_array_head();
894 UnrollBlock* info = array->unroll_block();
895
896 // We set the last_Java frame. But the stack isn't really parsable here. So we
897 // clear it to make sure JFR understands not to try and walk stacks from events
898 // in here.
899 intptr_t* sp = thread->frame_anchor()->last_Java_sp();
900 thread->frame_anchor()->set_last_Java_sp(nullptr);
901
902 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
903 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
904
905 thread->frame_anchor()->set_last_Java_sp(sp);
906
907 BasicType bt = info->return_type();
908
909 // If we have an exception pending, claim that the return type is an oop
910 // so the deopt_blob does not overwrite the exception_oop.
911
912 if (exec_mode == Unpack_exception)
913 bt = T_OBJECT;
914
915 // Cleanup thread deopt data
916 cleanup_deopt_info(thread, array);
917
918 #ifndef PRODUCT
919 if (VerifyStack) {
920 ResourceMark res_mark;
921 // Clear pending exception to not break verification code (restored afterwards)
922 PreserveExceptionMark pm(thread);
923
924 thread->validate_frame_layout();
925
926 // Verify that the just-unpacked frames match the interpreter's
927 // notions of expression stack and locals
928 vframeArray* cur_array = thread->vframe_array_last();
929 RegisterMap rm(thread,
930 RegisterMap::UpdateMap::skip,
931 RegisterMap::ProcessFrames::include,
932 RegisterMap::WalkContinuation::skip);
933 rm.set_include_argument_oops(false);
934 int callee_size_of_parameters = 0;
935 for (int frame_idx = 0; frame_idx < cur_array->frames(); frame_idx++) {
936 bool is_top_frame = (frame_idx == 0);
937 vframeArrayElement* el = cur_array->element(frame_idx);
938 frame* iframe = el->iframe();
939 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
940 methodHandle mh(thread, iframe->interpreter_frame_method());
941 bool reexecute = el->should_reexecute();
942
943 int cur_invoke_parameter_size = 0;
944 int top_frame_expression_stack_adjustment = 0;
945 int max_bci = mh->code_size();
946 BytecodeStream str(mh, iframe->interpreter_frame_bci());
947 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
948 Bytecodes::Code cur_code = str.next();
949
950 if (!reexecute && !Bytecodes::is_invoke(cur_code)) {
951 // We can only compute OopMaps for the before state, so we need to roll forward
952 // to the next bytecode.
953 assert(is_top_frame, "must be");
954 assert(falls_through(cur_code), "must be");
955 assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
956 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
957
958 // Need to subtract off the size of the result type of
959 // the bytecode because this is not described in the
960 // debug info but returned to the interpreter in the TOS
961 // caching register
962 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
963 if (bytecode_result_type != T_ILLEGAL) {
964 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
965 }
966 assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
967
968 cur_code = str.next();
969 // Reflect the fact that we have rolled forward and now need
970 // top_frame_expression_stack_adjustment
971 reexecute = true;
972 }
973
974 assert(cur_code != Bytecodes::_illegal, "illegal bytecode");
975 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
976
977 // Get the oop map for this bci
978 InterpreterOopMap mask;
979 OopMapCache::compute_one_oop_map(mh, str.bci(), &mask);
980 // Check to see if we can grab the number of outgoing arguments
981 // at an uncommon trap for an invoke (where the compiler
982 // generates debug info before the invoke has executed)
983 if (Bytecodes::is_invoke(cur_code)) {
984 Bytecode_invoke invoke(mh, str.bci());
985 cur_invoke_parameter_size = invoke.size_of_parameters();
986 if (!is_top_frame && invoke.has_member_arg()) {
987 callee_size_of_parameters++;
988 }
989 }
990
991 // Verify stack depth and oops in frame
992 auto match = [&]() {
993 int iframe_expr_ssize = iframe->interpreter_frame_expression_stack_size();
994 #if INCLUDE_JVMCI
995 if (is_top_frame && el->rethrow_exception()) {
996 return iframe_expr_ssize == 1;
997 }
998 #endif
999 // This should only be needed for C1
1000 if (is_top_frame && exec_mode == Unpack_exception && iframe_expr_ssize == 0) {
1001 return true;
1002 }
1003 if (reexecute) {
1004 int expr_ssize_before = iframe_expr_ssize + top_frame_expression_stack_adjustment;
1005 int oopmap_expr_invoke_ssize = mask.expression_stack_size() + cur_invoke_parameter_size;
1006 return expr_ssize_before == oopmap_expr_invoke_ssize;
1007 } else {
1008 int oopmap_expr_callee_ssize = mask.expression_stack_size() + callee_size_of_parameters;
1009 return iframe_expr_ssize == oopmap_expr_callee_ssize;
1010 }
1011 };
1012 if (!match()) {
1013 // Print out some information that will help us debug the problem
1014 tty->print_cr("Wrong number of expression stack elements during deoptimization");
1015 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", frame_idx, cur_array->frames() - 1);
1016 tty->print_cr(" Current code %s", Bytecodes::name(cur_code));
1017 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
1018 iframe->interpreter_frame_expression_stack_size());
1019 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
1020 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
1021 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
1022 tty->print_cr(" exec_mode = %d", exec_mode);
1023 tty->print_cr(" original should_reexecute = %s", el->should_reexecute() ? "true" : "false");
1024 tty->print_cr(" reexecute = %s%s", reexecute ? "true" : "false",
1025 (reexecute != el->should_reexecute()) ? " (changed)" : "");
1026 #if INCLUDE_JVMCI
1027 tty->print_cr(" rethrow_exception = %s", el->rethrow_exception() ? "true" : "false");
1028 #endif
1029 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
1030 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
1031 tty->print_cr(" Interpreted frames:");
1032 for (int k = 0; k < cur_array->frames(); k++) {
1033 vframeArrayElement* el = cur_array->element(k);
1034 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
1035 }
1036 cur_array->print_on_2(tty);
1037 guarantee(false, "wrong number of expression stack elements during deopt");
1038 }
1039 VerifyOopClosure verify;
1040 iframe->oops_interpreted_do(&verify, &rm, false);
1041 callee_size_of_parameters = mh->size_of_parameters();
1042 }
1043 }
1044 #endif // !PRODUCT
1045
1046 return bt;
1047 JRT_END
1048
1049 class DeoptimizeMarkedHandshakeClosure : public HandshakeClosure {
1050 public:
1051 DeoptimizeMarkedHandshakeClosure() : HandshakeClosure("Deoptimize") {}
1052 void do_thread(Thread* thread) {
1053 JavaThread* jt = JavaThread::cast(thread);
1054 jt->deoptimize_marked_methods();
1055 }
1056 };
1057
1058 void Deoptimization::deoptimize_all_marked() {
1059 ResourceMark rm;
1060
1061 // Make the dependent methods not entrant
1062 CodeCache::make_marked_nmethods_deoptimized();
1063
1064 DeoptimizeMarkedHandshakeClosure deopt;
1065 if (SafepointSynchronize::is_at_safepoint()) {
1066 Threads::java_threads_do(&deopt);
1067 } else {
1068 Handshake::execute(&deopt);
1069 }
1070 }
1071
1072 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1073 = Deoptimization::Action_reinterpret;
1074
1075 #if INCLUDE_JVMCI
1076 template<typename CacheType>
1077 class BoxCacheBase : public CHeapObj<mtCompiler> {
1078 protected:
1079 static InstanceKlass* find_cache_klass(Thread* thread, Symbol* klass_name) {
1080 ResourceMark rm(thread);
1081 char* klass_name_str = klass_name->as_C_string();
1082 InstanceKlass* ik = SystemDictionary::find_instance_klass(thread, klass_name, Handle());
1083 guarantee(ik != nullptr, "%s must be loaded", klass_name_str);
1084 if (!ik->is_in_error_state()) {
1085 guarantee(ik->is_initialized(), "%s must be initialized", klass_name_str);
1086 CacheType::compute_offsets(ik);
1087 }
1088 return ik;
1089 }
1090 };
1091
1092 template<typename PrimitiveType, typename CacheType, typename BoxType> class BoxCache : public BoxCacheBase<CacheType> {
1093 PrimitiveType _low;
1094 PrimitiveType _high;
1095 jobject _cache;
1096 protected:
1097 static BoxCache<PrimitiveType, CacheType, BoxType> *_singleton;
1098 BoxCache(Thread* thread) {
1099 InstanceKlass* ik = BoxCacheBase<CacheType>::find_cache_klass(thread, CacheType::symbol());
1100 if (ik->is_in_error_state()) {
1101 _low = 1;
1102 _high = 0;
1103 _cache = nullptr;
1104 } else {
1105 objArrayOop cache = CacheType::cache(ik);
1106 assert(cache->length() > 0, "Empty cache");
1107 _low = BoxType::value(cache->obj_at(0));
1108 _high = checked_cast<PrimitiveType>(_low + cache->length() - 1);
1109 _cache = JNIHandles::make_global(Handle(thread, cache));
1110 }
1111 }
1112 ~BoxCache() {
1113 JNIHandles::destroy_global(_cache);
1114 }
1115 public:
1116 static BoxCache<PrimitiveType, CacheType, BoxType>* singleton(Thread* thread) {
1117 if (_singleton == nullptr) {
1118 BoxCache<PrimitiveType, CacheType, BoxType>* s = new BoxCache<PrimitiveType, CacheType, BoxType>(thread);
1119 if (!AtomicAccess::replace_if_null(&_singleton, s)) {
1120 delete s;
1121 }
1122 }
1123 return _singleton;
1124 }
1125 oop lookup(PrimitiveType value) {
1126 if (_low <= value && value <= _high) {
1127 int offset = checked_cast<int>(value - _low);
1128 return objArrayOop(JNIHandles::resolve_non_null(_cache))->obj_at(offset);
1129 }
1130 return nullptr;
1131 }
1132 oop lookup_raw(intptr_t raw_value, bool& cache_init_error) {
1133 if (_cache == nullptr) {
1134 cache_init_error = true;
1135 return nullptr;
1136 }
1137 // Have to cast to avoid little/big-endian problems.
1138 if (sizeof(PrimitiveType) > sizeof(jint)) {
1139 jlong value = (jlong)raw_value;
1140 return lookup(value);
1141 }
1142 PrimitiveType value = (PrimitiveType)*((jint*)&raw_value);
1143 return lookup(value);
1144 }
1145 };
1146
1147 typedef BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer> IntegerBoxCache;
1148 typedef BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long> LongBoxCache;
1149 typedef BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character> CharacterBoxCache;
1150 typedef BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short> ShortBoxCache;
1151 typedef BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte> ByteBoxCache;
1152
1153 template<> BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>* BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>::_singleton = nullptr;
1154 template<> BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>* BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>::_singleton = nullptr;
1155 template<> BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>* BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>::_singleton = nullptr;
1156 template<> BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>* BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>::_singleton = nullptr;
1157 template<> BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>* BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>::_singleton = nullptr;
1158
1159 class BooleanBoxCache : public BoxCacheBase<java_lang_Boolean> {
1160 jobject _true_cache;
1161 jobject _false_cache;
1162 protected:
1163 static BooleanBoxCache *_singleton;
1164 BooleanBoxCache(Thread *thread) {
1165 InstanceKlass* ik = find_cache_klass(thread, java_lang_Boolean::symbol());
1166 if (ik->is_in_error_state()) {
1167 _true_cache = nullptr;
1168 _false_cache = nullptr;
1169 } else {
1170 _true_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_TRUE(ik)));
1171 _false_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_FALSE(ik)));
1172 }
1173 }
1174 ~BooleanBoxCache() {
1175 JNIHandles::destroy_global(_true_cache);
1176 JNIHandles::destroy_global(_false_cache);
1177 }
1178 public:
1179 static BooleanBoxCache* singleton(Thread* thread) {
1180 if (_singleton == nullptr) {
1181 BooleanBoxCache* s = new BooleanBoxCache(thread);
1182 if (!AtomicAccess::replace_if_null(&_singleton, s)) {
1183 delete s;
1184 }
1185 }
1186 return _singleton;
1187 }
1188 oop lookup_raw(intptr_t raw_value, bool& cache_in_error) {
1189 if (_true_cache == nullptr) {
1190 cache_in_error = true;
1191 return nullptr;
1192 }
1193 // Have to cast to avoid little/big-endian problems.
1194 jboolean value = (jboolean)*((jint*)&raw_value);
1195 return lookup(value);
1196 }
1197 oop lookup(jboolean value) {
1198 if (value != 0) {
1199 return JNIHandles::resolve_non_null(_true_cache);
1200 }
1201 return JNIHandles::resolve_non_null(_false_cache);
1202 }
1203 };
1204
1205 BooleanBoxCache* BooleanBoxCache::_singleton = nullptr;
1206
1207 oop Deoptimization::get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, bool& cache_init_error, TRAPS) {
1208 Klass* k = java_lang_Class::as_Klass(bv->klass()->as_ConstantOopReadValue()->value()());
1209 BasicType box_type = vmClasses::box_klass_type(k);
1210 if (box_type != T_OBJECT) {
1211 StackValue* value = StackValue::create_stack_value(fr, reg_map, bv->field_at(box_type == T_LONG ? 1 : 0));
1212 switch(box_type) {
1213 case T_INT: return IntegerBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1214 case T_CHAR: return CharacterBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1215 case T_SHORT: return ShortBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1216 case T_BYTE: return ByteBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1217 case T_BOOLEAN: return BooleanBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1218 case T_LONG: return LongBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1219 default:;
1220 }
1221 }
1222 return nullptr;
1223 }
1224 #endif // INCLUDE_JVMCI
1225
1226 #if COMPILER2_OR_JVMCI
1227 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1228 Handle pending_exception(THREAD, thread->pending_exception());
1229 const char* exception_file = thread->exception_file();
1230 int exception_line = thread->exception_line();
1231 thread->clear_pending_exception();
1232
1233 bool failures = false;
1234
1235 for (int i = 0; i < objects->length(); i++) {
1236 assert(objects->at(i)->is_object(), "invalid debug information");
1237 ObjectValue* sv = (ObjectValue*) objects->at(i);
1238
1239 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1240 oop obj = nullptr;
1241
1242 bool cache_init_error = false;
1243 if (k->is_instance_klass()) {
1244 #if INCLUDE_JVMCI
1245 nmethod* nm = fr->cb()->as_nmethod_or_null();
1246 if (nm->is_compiled_by_jvmci() && sv->is_auto_box()) {
1247 AutoBoxObjectValue* abv = (AutoBoxObjectValue*) sv;
1248 obj = get_cached_box(abv, fr, reg_map, cache_init_error, THREAD);
1249 if (obj != nullptr) {
1250 // Set the flag to indicate the box came from a cache, so that we can skip the field reassignment for it.
1251 abv->set_cached(true);
1252 } else if (cache_init_error) {
1253 // Results in an OOME which is valid (as opposed to a class initialization error)
1254 // and is fine for the rare case a cache initialization failing.
1255 failures = true;
1256 }
1257 }
1258 #endif // INCLUDE_JVMCI
1259
1260 InstanceKlass* ik = InstanceKlass::cast(k);
1261 if (obj == nullptr && !cache_init_error) {
1262 InternalOOMEMark iom(THREAD);
1263 if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1264 obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1265 } else {
1266 obj = ik->allocate_instance(THREAD);
1267 }
1268 }
1269 } else if (k->is_typeArray_klass()) {
1270 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1271 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1272 int len = sv->field_size() / type2size[ak->element_type()];
1273 InternalOOMEMark iom(THREAD);
1274 obj = ak->allocate_instance(len, THREAD);
1275 } else if (k->is_objArray_klass()) {1276 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
1277 InternalOOMEMark iom(THREAD);
1278 obj = ak->allocate_instance(sv->field_size(), THREAD);
1279 }
1280
1281 if (obj == nullptr) {
1282 failures = true;
1283 }
1284
1285 assert(sv->value().is_null(), "redundant reallocation");
1286 assert(obj != nullptr || HAS_PENDING_EXCEPTION || cache_init_error, "allocation should succeed or we should get an exception");
1287 CLEAR_PENDING_EXCEPTION;
1288 sv->set_value(obj);
1289 }
1290
1291 if (failures) {
1292 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1293 } else if (pending_exception.not_null()) {
1294 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1295 }
1296
1297 return failures;
1298 }
1299
1300 #if INCLUDE_JVMCI
1301 /**
1302 * For primitive types whose kind gets "erased" at runtime (shorts become stack ints),
1303 * we need to somehow be able to recover the actual kind to be able to write the correct
1304 * amount of bytes.
1305 * For that purpose, this method assumes that, for an entry spanning n bytes at index i,
1306 * the entries at index n + 1 to n + i are 'markers'.
1307 * For example, if we were writing a short at index 4 of a byte array of size 8, the
1308 * expected form of the array would be:
1309 *
1310 * {b0, b1, b2, b3, INT, marker, b6, b7}
1311 *
1312 * Thus, in order to get back the size of the entry, we simply need to count the number
1313 * of marked entries
1314 *
1315 * @param virtualArray the virtualized byte array
1316 * @param i index of the virtual entry we are recovering
1317 * @return The number of bytes the entry spans
1318 */
1319 static int count_number_of_bytes_for_entry(ObjectValue *virtualArray, int i) {
1320 int index = i;
1321 while (++index < virtualArray->field_size() &&
1322 virtualArray->field_at(index)->is_marker()) {}
1323 return index - i;
1324 }
1325
1326 /**
1327 * If there was a guarantee for byte array to always start aligned to a long, we could
1328 * do a simple check on the parity of the index. Unfortunately, that is not always the
1329 * case. Thus, we check alignment of the actual address we are writing to.
1330 * In the unlikely case index 0 is 5-aligned for example, it would then be possible to
1331 * write a long to index 3.
1332 */
1333 static jbyte* check_alignment_get_addr(typeArrayOop obj, int index, int expected_alignment) {
1334 jbyte* res = obj->byte_at_addr(index);
1335 assert((((intptr_t) res) % expected_alignment) == 0, "Non-aligned write");
1336 return res;
1337 }
1338
1339 static void byte_array_put(typeArrayOop obj, StackValue* value, int index, int byte_count) {
1340 switch (byte_count) {
1341 case 1:
1342 obj->byte_at_put(index, (jbyte) value->get_jint());
1343 break;
1344 case 2:
1345 *((jshort *) check_alignment_get_addr(obj, index, 2)) = (jshort) value->get_jint();
1346 break;
1347 case 4:
1348 *((jint *) check_alignment_get_addr(obj, index, 4)) = value->get_jint();
1349 break;
1350 case 8:
1351 *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) value->get_intptr();
1352 break;
1353 default:
1354 ShouldNotReachHere();
1355 }
1356 }
1357 #endif // INCLUDE_JVMCI
1358
1359
1360 // restore elements of an eliminated type array
1361 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1362 int index = 0;
1363
1364 for (int i = 0; i < sv->field_size(); i++) {
1365 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1366 switch(type) {
1367 case T_LONG: case T_DOUBLE: {
1368 assert(value->type() == T_INT, "Agreement.");
1369 StackValue* low =
1370 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1371 #ifdef _LP64
1372 jlong res = (jlong)low->get_intptr();
1373 #else
1374 jlong res = jlong_from(value->get_jint(), low->get_jint());
1375 #endif
1376 obj->long_at_put(index, res);
1377 break;
1378 }
1379
1380 case T_INT: case T_FLOAT: { // 4 bytes.
1381 assert(value->type() == T_INT, "Agreement.");
1382 #if INCLUDE_JVMCI
1383 // big_value allows encoding double/long value as e.g. [int = 0, long], and storing
1384 // the value in two array elements.
1385 bool big_value = false;
1386 if (i + 1 < sv->field_size() && type == T_INT) {
1387 if (sv->field_at(i)->is_location()) {
1388 Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
1389 if (type == Location::dbl || type == Location::lng) {
1390 big_value = true;
1391 }
1392 } else if (sv->field_at(i)->is_constant_int()) {
1393 ScopeValue* next_scope_field = sv->field_at(i + 1);
1394 if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1395 big_value = true;
1396 }
1397 }
1398 }
1399
1400 if (big_value) {
1401 StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1402 #ifdef _LP64
1403 jlong res = (jlong)low->get_intptr();
1404 #else
1405 jlong res = jlong_from(value->get_jint(), low->get_jint());
1406 #endif
1407 obj->int_at_put(index, *(jint*)&res);
1408 obj->int_at_put(++index, *((jint*)&res + 1));
1409 } else {
1410 obj->int_at_put(index, value->get_jint());
1411 }
1412 #else // not INCLUDE_JVMCI
1413 obj->int_at_put(index, value->get_jint());
1414 #endif // INCLUDE_JVMCI
1415 break;
1416 }
1417
1418 case T_SHORT:
1419 assert(value->type() == T_INT, "Agreement.");
1420 obj->short_at_put(index, (jshort)value->get_jint());
1421 break;
1422
1423 case T_CHAR:
1424 assert(value->type() == T_INT, "Agreement.");
1425 obj->char_at_put(index, (jchar)value->get_jint());
1426 break;
1427
1428 case T_BYTE: {
1429 assert(value->type() == T_INT, "Agreement.");
1430 #if INCLUDE_JVMCI
1431 // The value we get is erased as a regular int. We will need to find its actual byte count 'by hand'.
1432 int byte_count = count_number_of_bytes_for_entry(sv, i);
1433 byte_array_put(obj, value, index, byte_count);
1434 // According to byte_count contract, the values from i + 1 to i + byte_count are illegal values. Skip.
1435 i += byte_count - 1; // Balance the loop counter.
1436 index += byte_count;
1437 // index has been updated so continue at top of loop
1438 continue;
1439 #else
1440 obj->byte_at_put(index, (jbyte)value->get_jint());
1441 break;
1442 #endif // INCLUDE_JVMCI
1443 }
1444
1445 case T_BOOLEAN: {
1446 assert(value->type() == T_INT, "Agreement.");
1447 obj->bool_at_put(index, (jboolean)value->get_jint());
1448 break;
1449 }
1450
1451 default:
1452 ShouldNotReachHere();
1453 }
1454 index++;
1455 }
1456 }
1457
1458 // restore fields of an eliminated object array
1459 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1460 for (int i = 0; i < sv->field_size(); i++) {
1461 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1462 assert(value->type() == T_OBJECT, "object element expected");
1463 obj->obj_at_put(i, value->get_obj()());
1464 }
1465 }
1466
1467 class ReassignedField {
1468 public:
1469 int _offset;
1470 BasicType _type;
1471 public:
1472 ReassignedField() {1473 _offset = 0;1474 _type = T_ILLEGAL;1475 }
1476 };
1477
1478 // Gets the fields of `klass` that are eliminated by escape analysis and need to be reassigned
1479 static GrowableArray<ReassignedField>* get_reassigned_fields(InstanceKlass* klass, GrowableArray<ReassignedField>* fields, bool is_jvmci) {
1480 InstanceKlass* super = klass->super();
1481 if (super != nullptr) {
1482 get_reassigned_fields(super, fields, is_jvmci);
1483 }
1484 for (AllFieldStream fs(klass); !fs.done(); fs.next()) {
1485 if (!fs.access_flags().is_static() && (is_jvmci || !fs.field_flags().is_injected())) {
1486 ReassignedField field;
1487 field._offset = fs.offset();
1488 field._type = Signature::basic_type(fs.signature());
1489 fields->append(field);
1490 }
1491 }
1492 return fields;
1493 }
1494
1495 // Restore fields of an eliminated instance object employing the same field order used by the compiler.1496 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool is_jvmci) {
1497 GrowableArray<ReassignedField>* fields = get_reassigned_fields(klass, new GrowableArray<ReassignedField>(), is_jvmci);
1498 for (int i = 0; i < fields->length(); i++) {
1499 ScopeValue* scope_field = sv->field_at(svIndex);
1500 StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1501 int offset = fields->at(i)._offset;1502 BasicType type = fields->at(i)._type;
1503 switch (type) {
1504 case T_OBJECT: case T_ARRAY:
1505 assert(value->type() == T_OBJECT, "Agreement.");
1506 obj->obj_field_put(offset, value->get_obj()());
1507 break;
1508
1509 case T_INT: case T_FLOAT: { // 4 bytes.
1510 assert(value->type() == T_INT, "Agreement.");
1511 bool big_value = false;
1512 if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1513 if (scope_field->is_location()) {
1514 Location::Type type = ((LocationValue*) scope_field)->location().type();
1515 if (type == Location::dbl || type == Location::lng) {
1516 big_value = true;
1517 }
1518 }
1519 if (scope_field->is_constant_int()) {
1520 ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1521 if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1522 big_value = true;
1523 }
1524 }
1525 }
1526
1527 if (big_value) {
1528 i++;
1529 assert(i < fields->length(), "second T_INT field needed");
1530 assert(fields->at(i)._type == T_INT, "T_INT field needed");
1531 } else {
1532 obj->int_field_put(offset, value->get_jint());
1533 break;
1534 }
1535 }
1536 /* no break */
1537
1538 case T_LONG: case T_DOUBLE: {
1539 assert(value->type() == T_INT, "Agreement.");
1540 StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1541 #ifdef _LP64
1542 jlong res = (jlong)low->get_intptr();
1543 #else
1544 jlong res = jlong_from(value->get_jint(), low->get_jint());
1545 #endif
1546 obj->long_field_put(offset, res);
1547 break;
1548 }
1549
1550 case T_SHORT:
1551 assert(value->type() == T_INT, "Agreement.");
1552 obj->short_field_put(offset, (jshort)value->get_jint());
1553 break;
1554
1555 case T_CHAR:
1556 assert(value->type() == T_INT, "Agreement.");
1557 obj->char_field_put(offset, (jchar)value->get_jint());
1558 break;
1559
1560 case T_BYTE:
1561 assert(value->type() == T_INT, "Agreement.");
1562 obj->byte_field_put(offset, (jbyte)value->get_jint());
1563 break;
1564
1565 case T_BOOLEAN:
1566 assert(value->type() == T_INT, "Agreement.");
1567 obj->bool_field_put(offset, (jboolean)value->get_jint());
1568 break;
1569
1570 default:
1571 ShouldNotReachHere();
1572 }
1573 svIndex++;
1574 }
1575 return svIndex;
1576 }
1577
1578 // restore fields of all eliminated objects and arrays
1579 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool is_jvmci) {
1580 for (int i = 0; i < objects->length(); i++) {
1581 assert(objects->at(i)->is_object(), "invalid debug information");
1582 ObjectValue* sv = (ObjectValue*) objects->at(i);
1583 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1584 Handle obj = sv->value();
1585 assert(obj.not_null() || realloc_failures, "reallocation was missed");
1586 #ifndef PRODUCT
1587 if (PrintDeoptimizationDetails) {
1588 tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1589 }
1590 #endif // !PRODUCT
1591
1592 if (obj.is_null()) {
1593 continue;
1594 }
1595
1596 #if INCLUDE_JVMCI
1597 // Don't reassign fields of boxes that came from a cache. Caches may be in CDS.
1598 if (sv->is_auto_box() && ((AutoBoxObjectValue*) sv)->is_cached()) {
1599 continue;
1600 }
1601 #endif // INCLUDE_JVMCI
1602 if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1603 assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1604 ScopeValue* payload = sv->field_at(0);
1605 if (payload->is_location() &&
1606 payload->as_LocationValue()->location().type() == Location::vector) {
1607 #ifndef PRODUCT
1608 if (PrintDeoptimizationDetails) {
1609 tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1610 if (Verbose) {
1611 Handle obj = sv->value();
1612 k->oop_print_on(obj(), tty);
1613 }
1614 }
1615 #endif // !PRODUCT
1616 continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1617 }
1618 // Else fall-through to do assignment for scalar-replaced boxed vector representation
1619 // which could be restored after vector object allocation.
1620 }
1621 if (k->is_instance_klass()) {
1622 InstanceKlass* ik = InstanceKlass::cast(k);
1623 reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), is_jvmci);
1624 } else if (k->is_typeArray_klass()) {
1625 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1626 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1627 } else if (k->is_objArray_klass()) {
1628 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1629 }
1630 }
1631 // These objects may escape when we return to Interpreter after deoptimization.
1632 // We need barrier so that stores that initialize these objects can't be reordered
1633 // with subsequent stores that make these objects accessible by other threads.
1634 OrderAccess::storestore();
1635 }
1636
1637
1638 // relock objects for which synchronization was eliminated
1639 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1640 JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1641 bool relocked_objects = false;
1642 for (int i = 0; i < monitors->length(); i++) {
1643 MonitorInfo* mon_info = monitors->at(i);
1644 if (mon_info->eliminated()) {
1645 assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1646 relocked_objects = true;
1647 if (!mon_info->owner_is_scalar_replaced()) {
1648 Handle obj(thread, mon_info->owner());
1649 markWord mark = obj->mark();
1650 if (exec_mode == Unpack_none) {
1651 if (mark.has_monitor()) {
1652 // defer relocking if the deoptee thread is currently waiting for obj
1653 ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1654 if (waiting_monitor != nullptr && waiting_monitor->object() == obj()) {
1655 assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1656 if (UseObjectMonitorTable) {
1657 mon_info->lock()->clear_object_monitor_cache();
1658 }
1659 #ifdef ASSERT
1660 else {
1661 assert(!UseObjectMonitorTable, "must be");
1662 mon_info->lock()->set_bad_monitor_deopt();
1663 }
1664 #endif
1665 JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1666 continue;
1667 }
1668 }
1669 }
1670 BasicLock* lock = mon_info->lock();
1671 // We have lost information about the correct state of the lock stack.
1672 // Entering may create an invalid lock stack. Inflate the lock if it
1673 // was fast_locked to restore the valid lock stack.
1674 if (UseObjectMonitorTable) {
1675 // UseObjectMonitorTable expects the BasicLock cache to be either a
1676 // valid ObjectMonitor* or nullptr. Right now it is garbage, set it
1677 // to nullptr.
1678 lock->clear_object_monitor_cache();
1679 }
1680 ObjectSynchronizer::enter_for(obj, lock, deoptee_thread);
1681 if (deoptee_thread->lock_stack().contains(obj())) {
1682 ObjectSynchronizer::inflate_fast_locked_object(obj(), ObjectSynchronizer::InflateCause::inflate_cause_vm_internal,
1683 deoptee_thread, thread);
1684 }
1685 assert(mon_info->owner()->is_locked(), "object must be locked now");
1686 assert(obj->mark().has_monitor(), "must be");
1687 assert(!deoptee_thread->lock_stack().contains(obj()), "must be");
1688 assert(ObjectSynchronizer::read_monitor(thread, obj(), obj->mark())->has_owner(deoptee_thread), "must be");
1689 }
1690 }
1691 }
1692 return relocked_objects;
1693 }
1694 #endif // COMPILER2_OR_JVMCI
1695
1696 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1697 Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1698
1699 // Register map for next frame (used for stack crawl). We capture
1700 // the state of the deopt'ing frame's caller. Thus if we need to
1701 // stuff a C2I adapter we can properly fill in the callee-save
1702 // register locations.
1703 frame caller = fr.sender(reg_map);
1704 int frame_size = pointer_delta_as_int(caller.sp(), fr.sp());
1705
1706 frame sender = caller;
1707
1708 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1709 // the vframeArray containing the unpacking information is allocated in the C heap.
1710 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1711 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1712
1713 // Compare the vframeArray to the collected vframes
1714 assert(array->structural_compare(thread, chunk), "just checking");
1715
1716 if (TraceDeoptimization) {
1717 ResourceMark rm;
1718 stringStream st;
1719 st.print_cr("DEOPT PACKING thread=" INTPTR_FORMAT " vframeArray=" INTPTR_FORMAT, p2i(thread), p2i(array));
1720 st.print(" ");
1721 fr.print_on(&st);
1722 st.print_cr(" Virtual frames (innermost/newest first):");
1723 for (int index = 0; index < chunk->length(); index++) {
1724 compiledVFrame* vf = chunk->at(index);
1725 int bci = vf->raw_bci();
1726 const char* code_name;
1727 if (bci == SynchronizationEntryBCI) {
1728 code_name = "sync entry";
1729 } else {
1730 Bytecodes::Code code = vf->method()->code_at(bci);
1731 code_name = Bytecodes::name(code);
1732 }
1733
1734 st.print(" VFrame %d (" INTPTR_FORMAT ")", index, p2i(vf));
1735 st.print(" - %s", vf->method()->name_and_sig_as_C_string());
1736 st.print(" - %s", code_name);
1737 st.print_cr(" @ bci=%d ", bci);
1738 }
1739 tty->print_raw(st.freeze());
1740 tty->cr();
1741 }
1742
1743 return array;
1744 }
1745
1746 #if COMPILER2_OR_JVMCI
1747 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1748 // Reallocation of some scalar replaced objects failed. Record
1749 // that we need to pop all the interpreter frames for the
1750 // deoptimized compiled frame.
1751 assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1752 thread->set_frames_to_pop_failed_realloc(array->frames());
1753 // Unlock all monitors here otherwise the interpreter will see a
1754 // mix of locked and unlocked monitors (because of failed
1755 // reallocations of synchronized objects) and be confused.
1756 for (int i = 0; i < array->frames(); i++) {
1757 MonitorChunk* monitors = array->element(i)->monitors();
1758 if (monitors != nullptr) {
1759 // Unlock in reverse order starting from most nested monitor.
1760 for (int j = (monitors->number_of_monitors() - 1); j >= 0; j--) {
1761 BasicObjectLock* src = monitors->at(j);
1762 if (src->obj() != nullptr) {
1763 ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1764 }
1765 }
1766 array->element(i)->free_monitors();
1767 #ifdef ASSERT
1768 array->element(i)->set_removed_monitors();
1769 #endif
1770 }
1771 }
1772 }
1773 #endif
1774
1775 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1776 assert(fr.can_be_deoptimized(), "checking frame type");
1777
1778 gather_statistics(reason, Action_none, Bytecodes::_illegal);
1779
1780 if (LogCompilation && xtty != nullptr) {
1781 nmethod* nm = fr.cb()->as_nmethod_or_null();
1782 assert(nm != nullptr, "only compiled methods can deopt");
1783
1784 ttyLocker ttyl;
1785 xtty->begin_head("deoptimized thread='%zu' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1786 nm->log_identity(xtty);
1787 xtty->end_head();
1788 for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1789 xtty->begin_elem("jvms bci='%d'", sd->bci());
1790 xtty->method(sd->method());
1791 xtty->end_elem();
1792 if (sd->is_top()) break;
1793 }
1794 xtty->tail("deoptimized");
1795 }
1796
1797 Continuation::notify_deopt(thread, fr.sp());
1798
1799 // Patch the compiled method so that when execution returns to it we will
1800 // deopt the execution state and return to the interpreter.
1801 fr.deoptimize(thread);
1802 }
1803
1804 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1805 // Deoptimize only if the frame comes from compile code.
1806 // Do not deoptimize the frame which is already patched
1807 // during the execution of the loops below.
1808 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1809 return;
1810 }
1811 ResourceMark rm;
1812 deoptimize_single_frame(thread, fr, reason);
1813 }
1814
1815 address Deoptimization::deoptimize_for_missing_exception_handler(nmethod* nm, bool make_not_entrant) {
1816 // there is no exception handler for this pc => deoptimize
1817 if (make_not_entrant) {
1818 nm->make_not_entrant(nmethod::InvalidationReason::MISSING_EXCEPTION_HANDLER);
1819 }
1820
1821 // Use Deoptimization::deoptimize for all of its side-effects:
1822 // gathering traps statistics, logging...
1823 // it also patches the return pc but we do not care about that
1824 // since we return a continuation to the deopt_blob below.
1825 JavaThread* thread = JavaThread::current();
1826 RegisterMap reg_map(thread,
1827 RegisterMap::UpdateMap::skip,
1828 RegisterMap::ProcessFrames::include,
1829 RegisterMap::WalkContinuation::skip);
1830 frame runtime_frame = thread->last_frame();
1831 frame caller_frame = runtime_frame.sender(®_map);
1832 assert(caller_frame.cb()->as_nmethod_or_null() == nm, "expect top frame compiled method");
1833
1834 Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1835
1836 if (!nm->is_compiled_by_jvmci()) {
1837 return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1838 }
1839
1840 #if INCLUDE_JVMCI
1841 // JVMCI support
1842 vframe* vf = vframe::new_vframe(&caller_frame, ®_map, thread);
1843 compiledVFrame* cvf = compiledVFrame::cast(vf);
1844 ScopeDesc* imm_scope = cvf->scope();
1845 MethodData* imm_mdo = get_method_data(thread, methodHandle(thread, imm_scope->method()), true);
1846 if (imm_mdo != nullptr) {
1847 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
1848 MutexLocker ml(imm_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
1849
1850 ProfileData* pdata = imm_mdo->allocate_bci_to_data(imm_scope->bci(), nullptr);
1851 if (pdata != nullptr && pdata->is_BitData()) {
1852 BitData* bit_data = (BitData*) pdata;
1853 bit_data->set_exception_seen();
1854 }
1855 }
1856
1857
1858 MethodData* trap_mdo = get_method_data(thread, methodHandle(thread, nm->method()), true);
1859 if (trap_mdo != nullptr) {
1860 trap_mdo->inc_trap_count(Deoptimization::Reason_not_compiled_exception_handler);
1861 }
1862 #endif
1863
1864 return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1865 }
1866
1867 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1868 assert(thread == Thread::current() ||
1869 thread->is_handshake_safe_for(Thread::current()) ||
1870 SafepointSynchronize::is_at_safepoint(),
1871 "can only deoptimize other thread at a safepoint/handshake");
1872 // Compute frame and register map based on thread and sp.
1873 RegisterMap reg_map(thread,
1874 RegisterMap::UpdateMap::skip,
1875 RegisterMap::ProcessFrames::include,
1876 RegisterMap::WalkContinuation::skip);
1877 frame fr = thread->last_frame();
1878 while (fr.id() != id) {
1879 fr = fr.sender(®_map);
1880 }
1881 deoptimize(thread, fr, reason);
1882 }
1883
1884
1885 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1886 Thread* current = Thread::current();
1887 if (thread == current || thread->is_handshake_safe_for(current)) {
1888 Deoptimization::deoptimize_frame_internal(thread, id, reason);
1889 } else {
1890 VM_DeoptimizeFrame deopt(thread, id, reason);
1891 VMThread::execute(&deopt);
1892 }
1893 }
1894
1895 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1896 deoptimize_frame(thread, id, Reason_constraint);
1897 }
1898
1899 // JVMTI PopFrame support
1900 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1901 {
1902 assert(thread == JavaThread::current(), "pre-condition");
1903 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1904 }
1905 JRT_END
1906
1907 MethodData*
1908 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1909 bool create_if_missing) {
1910 JavaThread* THREAD = thread; // For exception macros.
1911 MethodData* mdo = m()->method_data();
1912 if (mdo == nullptr && create_if_missing && !HAS_PENDING_EXCEPTION) {
1913 // Build an MDO. Ignore errors like OutOfMemory;
1914 // that simply means we won't have an MDO to update.
1915 Method::build_profiling_method_data(m, THREAD);
1916 if (HAS_PENDING_EXCEPTION) {
1917 // Only metaspace OOM is expected. No Java code executed.
1918 assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1919 CLEAR_PENDING_EXCEPTION;
1920 }
1921 mdo = m()->method_data();
1922 }
1923 return mdo;
1924 }
1925
1926 #if COMPILER2_OR_JVMCI
1927 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1928 // In case of an unresolved klass entry, load the class.
1929 // This path is exercised from case _ldc in Parse::do_one_bytecode,
1930 // and probably nowhere else.
1931 // Even that case would benefit from simply re-interpreting the
1932 // bytecode, without paying special attention to the class index.
1933 // So this whole "class index" feature should probably be removed.
1934
1935 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1936 Klass* tk = constant_pool->klass_at(index, THREAD);
1937 if (HAS_PENDING_EXCEPTION) {
1938 // Exception happened during classloading. We ignore the exception here, since it
1939 // is going to be rethrown since the current activation is going to be deoptimized and
1940 // the interpreter will re-execute the bytecode.
1941 // Do not clear probable Async Exceptions.
1942 CLEAR_PENDING_NONASYNC_EXCEPTION;
1943 // Class loading called java code which may have caused a stack
1944 // overflow. If the exception was thrown right before the return
1945 // to the runtime the stack is no longer guarded. Reguard the
1946 // stack otherwise if we return to the uncommon trap blob and the
1947 // stack bang causes a stack overflow we crash.
1948 JavaThread* jt = THREAD;
1949 bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1950 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1951 }
1952 return;
1953 }
1954
1955 assert(!constant_pool->tag_at(index).is_symbol(),
1956 "no symbolic names here, please");
1957 }
1958
1959 #if INCLUDE_JFR
1960
1961 class DeoptReasonSerializer : public JfrSerializer {
1962 public:
1963 void serialize(JfrCheckpointWriter& writer) {
1964 writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
1965 for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
1966 writer.write_key((u8)i);
1967 writer.write(Deoptimization::trap_reason_name(i));
1968 }
1969 }
1970 };
1971
1972 class DeoptActionSerializer : public JfrSerializer {
1973 public:
1974 void serialize(JfrCheckpointWriter& writer) {
1975 static const u4 nof_actions = Deoptimization::Action_LIMIT;
1976 writer.write_count(nof_actions);
1977 for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
1978 writer.write_key(i);
1979 writer.write(Deoptimization::trap_action_name((int)i));
1980 }
1981 }
1982 };
1983
1984 static void register_serializers() {
1985 static int critical_section = 0;
1986 if (1 == critical_section || AtomicAccess::cmpxchg(&critical_section, 0, 1) == 1) {
1987 return;
1988 }
1989 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
1990 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
1991 }
1992
1993 static void post_deoptimization_event(nmethod* nm,
1994 const Method* method,
1995 int trap_bci,
1996 int instruction,
1997 Deoptimization::DeoptReason reason,
1998 Deoptimization::DeoptAction action) {
1999 assert(nm != nullptr, "invariant");
2000 assert(method != nullptr, "invariant");
2001 if (EventDeoptimization::is_enabled()) {
2002 static bool serializers_registered = false;
2003 if (!serializers_registered) {
2004 register_serializers();
2005 serializers_registered = true;
2006 }
2007 EventDeoptimization event;
2008 event.set_compileId(nm->compile_id());
2009 event.set_compiler(nm->compiler_type());
2010 event.set_method(method);
2011 event.set_lineNumber(method->line_number_from_bci(trap_bci));
2012 event.set_bci(trap_bci);
2013 event.set_instruction(instruction);
2014 event.set_reason(reason);
2015 event.set_action(action);
2016 event.commit();
2017 }
2018 }
2019
2020 #endif // INCLUDE_JFR
2021
2022 static void log_deopt(nmethod* nm, Method* tm, intptr_t pc, frame& fr, int trap_bci,
2023 const char* reason_name, const char* reason_action) {
2024 LogTarget(Debug, deoptimization) lt;
2025 if (lt.is_enabled()) {
2026 LogStream ls(lt);
2027 bool is_osr = nm->is_osr_method();
2028 ls.print("cid=%4d %s level=%d",
2029 nm->compile_id(), (is_osr ? "osr" : " "), nm->comp_level());
2030 ls.print(" %s", tm->name_and_sig_as_C_string());
2031 ls.print(" trap_bci=%d ", trap_bci);
2032 if (is_osr) {
2033 ls.print("osr_bci=%d ", nm->osr_entry_bci());
2034 }
2035 ls.print("%s ", reason_name);
2036 ls.print("%s ", reason_action);
2037 ls.print_cr("pc=" INTPTR_FORMAT " relative_pc=" INTPTR_FORMAT,
2038 pc, fr.pc() - nm->code_begin());
2039 }
2040 }
2041
2042 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
2043 HandleMark hm(current);
2044
2045 // uncommon_trap() is called at the beginning of the uncommon trap
2046 // handler. Note this fact before we start generating temporary frames
2047 // that can confuse an asynchronous stack walker. This counter is
2048 // decremented at the end of unpack_frames().
2049
2050 current->inc_in_deopt_handler();
2051
2052 #if INCLUDE_JVMCI
2053 // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
2054 RegisterMap reg_map(current,
2055 RegisterMap::UpdateMap::include,
2056 RegisterMap::ProcessFrames::include,
2057 RegisterMap::WalkContinuation::skip);
2058 #else
2059 RegisterMap reg_map(current,
2060 RegisterMap::UpdateMap::skip,
2061 RegisterMap::ProcessFrames::include,
2062 RegisterMap::WalkContinuation::skip);
2063 #endif
2064 frame stub_frame = current->last_frame();
2065 frame fr = stub_frame.sender(®_map);
2066
2067 // Log a message
2068 Events::log_deopt_message(current, "Uncommon trap: trap_request=" INT32_FORMAT_X_0 " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
2069 trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
2070
2071 {
2072 ResourceMark rm;
2073
2074 DeoptReason reason = trap_request_reason(trap_request);
2075 DeoptAction action = trap_request_action(trap_request);
2076 #if INCLUDE_JVMCI
2077 int debug_id = trap_request_debug_id(trap_request);
2078 #endif
2079 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
2080
2081 vframe* vf = vframe::new_vframe(&fr, ®_map, current);
2082 compiledVFrame* cvf = compiledVFrame::cast(vf);
2083
2084 nmethod* nm = cvf->code();
2085
2086 ScopeDesc* trap_scope = cvf->scope();
2087
2088 bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
2089
2090 if (is_receiver_constraint_failure) {
2091 tty->print_cr(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"),
2092 trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
2093 JVMCI_ONLY(COMMA debug_id));
2094 }
2095
2096 methodHandle trap_method(current, trap_scope->method());
2097 int trap_bci = trap_scope->bci();
2098 #if INCLUDE_JVMCI
2099 jlong speculation = current->pending_failed_speculation();
2100 if (nm->is_compiled_by_jvmci()) {
2101 nm->update_speculation(current);
2102 } else {
2103 assert(speculation == 0, "There should not be a speculation for methods compiled by non-JVMCI compilers");
2104 }
2105
2106 if (trap_bci == SynchronizationEntryBCI) {
2107 trap_bci = 0;
2108 current->set_pending_monitorenter(true);
2109 }
2110
2111 if (reason == Deoptimization::Reason_transfer_to_interpreter) {
2112 current->set_pending_transfer_to_interpreter(true);
2113 }
2114 #endif
2115
2116 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
2117 // Record this event in the histogram.
2118 gather_statistics(reason, action, trap_bc);
2119
2120 // Ensure that we can record deopt. history:
2121 bool create_if_missing = ProfileTraps;
2122
2123 methodHandle profiled_method;
2124 #if INCLUDE_JVMCI
2125 if (nm->is_compiled_by_jvmci()) {
2126 profiled_method = methodHandle(current, nm->method());
2127 } else {
2128 profiled_method = trap_method;
2129 }
2130 #else
2131 profiled_method = trap_method;
2132 #endif
2133
2134 MethodData* trap_mdo =
2135 get_method_data(current, profiled_method, create_if_missing);
2136
2137 { // Log Deoptimization event for JFR, UL and event system
2138 Method* tm = trap_method();
2139 const char* reason_name = trap_reason_name(reason);
2140 const char* reason_action = trap_action_name(action);
2141 intptr_t pc = p2i(fr.pc());
2142
2143 JFR_ONLY(post_deoptimization_event(nm, tm, trap_bci, trap_bc, reason, action);)
2144 log_deopt(nm, tm, pc, fr, trap_bci, reason_name, reason_action);
2145 Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s",
2146 reason_name, reason_action, pc,
2147 tm->name_and_sig_as_C_string(), trap_bci, nm->compiler_name());
2148 }
2149
2150 // Print a bunch of diagnostics, if requested.
2151 if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
2152 ResourceMark rm;
2153
2154 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2155 // We must do this already now, since we cannot acquire this lock while
2156 // holding the tty lock (lock ordering by rank).
2157 MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2158
2159 ttyLocker ttyl;
2160
2161 char buf[100];
2162 if (xtty != nullptr) {
2163 xtty->begin_head("uncommon_trap thread='%zu' %s",
2164 os::current_thread_id(),
2165 format_trap_request(buf, sizeof(buf), trap_request));
2166 #if INCLUDE_JVMCI
2167 if (speculation != 0) {
2168 xtty->print(" speculation='" JLONG_FORMAT "'", speculation);
2169 }
2170 #endif
2171 nm->log_identity(xtty);
2172 }
2173 Symbol* class_name = nullptr;
2174 bool unresolved = false;
2175 if (unloaded_class_index >= 0) {
2176 constantPoolHandle constants (current, trap_method->constants());
2177 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
2178 class_name = constants->klass_name_at(unloaded_class_index);
2179 unresolved = true;
2180 if (xtty != nullptr)
2181 xtty->print(" unresolved='1'");
2182 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
2183 class_name = constants->symbol_at(unloaded_class_index);
2184 }
2185 if (xtty != nullptr)
2186 xtty->name(class_name);
2187 }
2188 if (xtty != nullptr && trap_mdo != nullptr && (int)reason < (int)MethodData::_trap_hist_limit) {
2189 // Dump the relevant MDO state.
2190 // This is the deopt count for the current reason, any previous
2191 // reasons or recompiles seen at this point.
2192 int dcnt = trap_mdo->trap_count(reason);
2193 if (dcnt != 0)
2194 xtty->print(" count='%d'", dcnt);
2195
2196 // We need to lock to read the ProfileData. But to keep the locks ordered, we need to
2197 // lock extra_data_lock before the tty lock.
2198 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
2199 int dos = (pdata == nullptr)? 0: pdata->trap_state();
2200 if (dos != 0) {
2201 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
2202 if (trap_state_is_recompiled(dos)) {
2203 int recnt2 = trap_mdo->overflow_recompile_count();
2204 if (recnt2 != 0)
2205 xtty->print(" recompiles2='%d'", recnt2);
2206 }
2207 }
2208 }
2209 if (xtty != nullptr) {
2210 xtty->stamp();
2211 xtty->end_head();
2212 }
2213 if (TraceDeoptimization) { // make noise on the tty
2214 stringStream st;
2215 st.print("UNCOMMON TRAP method=%s", trap_scope->method()->name_and_sig_as_C_string());
2216 st.print(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT JVMCI_ONLY(", debug_id=%d"),
2217 trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin() JVMCI_ONLY(COMMA debug_id));
2218 st.print(" compiler=%s compile_id=%d", nm->compiler_name(), nm->compile_id());
2219 #if INCLUDE_JVMCI
2220 if (nm->is_compiled_by_jvmci()) {
2221 const char* installed_code_name = nm->jvmci_name();
2222 if (installed_code_name != nullptr) {
2223 st.print(" (JVMCI: installed code name=%s) ", installed_code_name);
2224 }
2225 }
2226 #endif
2227 st.print(" (@" INTPTR_FORMAT ") thread=%zu reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
2228 p2i(fr.pc()),
2229 os::current_thread_id(),
2230 trap_reason_name(reason),
2231 trap_action_name(action),
2232 unloaded_class_index
2233 #if INCLUDE_JVMCI
2234 , debug_id
2235 #endif
2236 );
2237 if (class_name != nullptr) {
2238 st.print(unresolved ? " unresolved class: " : " symbol: ");
2239 class_name->print_symbol_on(&st);
2240 }
2241 st.cr();
2242 tty->print_raw(st.freeze());
2243 }
2244 if (xtty != nullptr) {
2245 // Log the precise location of the trap.
2246 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2247 xtty->begin_elem("jvms bci='%d'", sd->bci());
2248 xtty->method(sd->method());
2249 xtty->end_elem();
2250 if (sd->is_top()) break;
2251 }
2252 xtty->tail("uncommon_trap");
2253 }
2254 }
2255 // (End diagnostic printout.)
2256
2257 if (is_receiver_constraint_failure) {
2258 fatal("missing receiver type check");
2259 }
2260
2261 // Load class if necessary
2262 if (unloaded_class_index >= 0) {
2263 constantPoolHandle constants(current, trap_method->constants());
2264 load_class_by_index(constants, unloaded_class_index, THREAD);
2265 }
2266
2267 // Flush the nmethod if necessary and desirable.
2268 //
2269 // We need to avoid situations where we are re-flushing the nmethod
2270 // because of a hot deoptimization site. Repeated flushes at the same
2271 // point need to be detected by the compiler and avoided. If the compiler
2272 // cannot avoid them (or has a bug and "refuses" to avoid them), this
2273 // module must take measures to avoid an infinite cycle of recompilation
2274 // and deoptimization. There are several such measures:
2275 //
2276 // 1. If a recompilation is ordered a second time at some site X
2277 // and for the same reason R, the action is adjusted to 'reinterpret',
2278 // to give the interpreter time to exercise the method more thoroughly.
2279 // If this happens, the method's overflow_recompile_count is incremented.
2280 //
2281 // 2. If the compiler fails to reduce the deoptimization rate, then
2282 // the method's overflow_recompile_count will begin to exceed the set
2283 // limit PerBytecodeRecompilationCutoff. If this happens, the action
2284 // is adjusted to 'make_not_compilable', and the method is abandoned
2285 // to the interpreter. This is a performance hit for hot methods,
2286 // but is better than a disastrous infinite cycle of recompilations.
2287 // (Actually, only the method containing the site X is abandoned.)
2288 //
2289 // 3. In parallel with the previous measures, if the total number of
2290 // recompilations of a method exceeds the much larger set limit
2291 // PerMethodRecompilationCutoff, the method is abandoned.
2292 // This should only happen if the method is very large and has
2293 // many "lukewarm" deoptimizations. The code which enforces this
2294 // limit is elsewhere (class nmethod, class Method).
2295 //
2296 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2297 // to recompile at each bytecode independently of the per-BCI cutoff.
2298 //
2299 // The decision to update code is up to the compiler, and is encoded
2300 // in the Action_xxx code. If the compiler requests Action_none
2301 // no trap state is changed, no compiled code is changed, and the
2302 // computation suffers along in the interpreter.
2303 //
2304 // The other action codes specify various tactics for decompilation
2305 // and recompilation. Action_maybe_recompile is the loosest, and
2306 // allows the compiled code to stay around until enough traps are seen,
2307 // and until the compiler gets around to recompiling the trapping method.
2308 //
2309 // The other actions cause immediate removal of the present code.
2310
2311 // Traps caused by injected profile shouldn't pollute trap counts.
2312 bool injected_profile_trap = trap_method->has_injected_profile() &&
2313 (reason == Reason_intrinsic || reason == Reason_unreached);
2314
2315 bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2316 bool make_not_entrant = false;
2317 bool make_not_compilable = false;
2318 bool reprofile = false;
2319 switch (action) {
2320 case Action_none:
2321 // Keep the old code.
2322 update_trap_state = false;
2323 break;
2324 case Action_maybe_recompile:
2325 // Do not need to invalidate the present code, but we can
2326 // initiate another
2327 // Start compiler without (necessarily) invalidating the nmethod.
2328 // The system will tolerate the old code, but new code should be
2329 // generated when possible.
2330 break;
2331 case Action_reinterpret:
2332 // Go back into the interpreter for a while, and then consider
2333 // recompiling form scratch.
2334 make_not_entrant = true;
2335 // Reset invocation counter for outer most method.
2336 // This will allow the interpreter to exercise the bytecodes
2337 // for a while before recompiling.
2338 // By contrast, Action_make_not_entrant is immediate.
2339 //
2340 // Note that the compiler will track null_check, null_assert,
2341 // range_check, and class_check events and log them as if they
2342 // had been traps taken from compiled code. This will update
2343 // the MDO trap history so that the next compilation will
2344 // properly detect hot trap sites.
2345 reprofile = true;
2346 break;
2347 case Action_make_not_entrant:
2348 // Request immediate recompilation, and get rid of the old code.
2349 // Make them not entrant, so next time they are called they get
2350 // recompiled. Unloaded classes are loaded now so recompile before next
2351 // time they are called. Same for uninitialized. The interpreter will
2352 // link the missing class, if any.
2353 make_not_entrant = true;
2354 break;
2355 case Action_make_not_compilable:
2356 // Give up on compiling this method at all.
2357 make_not_entrant = true;
2358 make_not_compilable = true;
2359 break;
2360 default:
2361 ShouldNotReachHere();
2362 }
2363
2364 #if INCLUDE_JVMCI
2365 // Deoptimization count is used by the CompileBroker to reason about compilations
2366 // it requests so do not pollute the count for deoptimizations in non-default (i.e.
2367 // non-CompilerBroker) compilations.
2368 if (nm->jvmci_skip_profile_deopt()) {
2369 update_trap_state = false;
2370 }
2371 #endif
2372 // Setting +ProfileTraps fixes the following, on all platforms:
2373 // The result is infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2374 // recompile relies on a MethodData* to record heroic opt failures.
2375
2376 // Whether the interpreter is producing MDO data or not, we also need
2377 // to use the MDO to detect hot deoptimization points and control
2378 // aggressive optimization.
2379 bool inc_recompile_count = false;
2380
2381 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2382 ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
2383 (trap_mdo != nullptr),
2384 Mutex::_no_safepoint_check_flag);
2385 ProfileData* pdata = nullptr;
2386 if (ProfileTraps && CompilerConfig::is_c2_or_jvmci_compiler_enabled() && update_trap_state && trap_mdo != nullptr) {
2387 assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2388 uint this_trap_count = 0;
2389 bool maybe_prior_trap = false;
2390 bool maybe_prior_recompile = false;
2391
2392 pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
2393 #if INCLUDE_JVMCI
2394 nm->is_compiled_by_jvmci() && nm->is_osr_method(),
2395 #endif
2396 nm->method(),
2397 //outputs:
2398 this_trap_count,
2399 maybe_prior_trap,
2400 maybe_prior_recompile);
2401 // Because the interpreter also counts null, div0, range, and class
2402 // checks, these traps from compiled code are double-counted.
2403 // This is harmless; it just means that the PerXTrapLimit values
2404 // are in effect a little smaller than they look.
2405
2406 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2407 if (per_bc_reason != Reason_none) {
2408 // Now take action based on the partially known per-BCI history.
2409 if (maybe_prior_trap
2410 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2411 // If there are too many traps at this BCI, force a recompile.
2412 // This will allow the compiler to see the limit overflow, and
2413 // take corrective action, if possible. The compiler generally
2414 // does not use the exact PerBytecodeTrapLimit value, but instead
2415 // changes its tactics if it sees any traps at all. This provides
2416 // a little hysteresis, delaying a recompile until a trap happens
2417 // several times.
2418 //
2419 // Actually, since there is only one bit of counter per BCI,
2420 // the possible per-BCI counts are {0,1,(per-method count)}.
2421 // This produces accurate results if in fact there is only
2422 // one hot trap site, but begins to get fuzzy if there are
2423 // many sites. For example, if there are ten sites each
2424 // trapping two or more times, they each get the blame for
2425 // all of their traps.
2426 make_not_entrant = true;
2427 }
2428
2429 // Detect repeated recompilation at the same BCI, and enforce a limit.
2430 if (make_not_entrant && maybe_prior_recompile) {
2431 // More than one recompile at this point.
2432 inc_recompile_count = maybe_prior_trap;
2433 }
2434 } else {
2435 // For reasons which are not recorded per-bytecode, we simply
2436 // force recompiles unconditionally.
2437 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2438 make_not_entrant = true;
2439 }
2440
2441 // Go back to the compiler if there are too many traps in this method.
2442 if (this_trap_count >= per_method_trap_limit(reason)) {
2443 // If there are too many traps in this method, force a recompile.
2444 // This will allow the compiler to see the limit overflow, and
2445 // take corrective action, if possible.
2446 // (This condition is an unlikely backstop only, because the
2447 // PerBytecodeTrapLimit is more likely to take effect first,
2448 // if it is applicable.)
2449 make_not_entrant = true;
2450 }
2451
2452 // Here's more hysteresis: If there has been a recompile at
2453 // this trap point already, run the method in the interpreter
2454 // for a while to exercise it more thoroughly.
2455 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2456 reprofile = true;
2457 }
2458 }
2459
2460 // Take requested actions on the method:
2461
2462 // Recompile
2463 if (make_not_entrant) {
2464 if (!nm->make_not_entrant(nmethod::InvalidationReason::UNCOMMON_TRAP)) {
2465 return; // the call did not change nmethod's state
2466 }
2467
2468 if (pdata != nullptr) {
2469 // Record the recompilation event, if any.
2470 int tstate0 = pdata->trap_state();
2471 int tstate1 = trap_state_set_recompiled(tstate0, true);
2472 if (tstate1 != tstate0)
2473 pdata->set_trap_state(tstate1);
2474 }
2475
2476 // For code aging we count traps separately here, using make_not_entrant()
2477 // as a guard against simultaneous deopts in multiple threads.
2478 if (reason == Reason_tenured && trap_mdo != nullptr) {
2479 trap_mdo->inc_tenure_traps();
2480 }
2481 }
2482 if (inc_recompile_count) {
2483 trap_mdo->inc_overflow_recompile_count();
2484 if ((uint)trap_mdo->overflow_recompile_count() >
2485 (uint)PerBytecodeRecompilationCutoff) {
2486 // Give up on the method containing the bad BCI.
2487 if (trap_method() == nm->method()) {
2488 make_not_compilable = true;
2489 } else {
2490 trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2491 // But give grace to the enclosing nm->method().
2492 }
2493 }
2494 }
2495
2496 // Reprofile
2497 if (reprofile) {
2498 CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2499 }
2500
2501 // Give up compiling
2502 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2503 assert(make_not_entrant, "consistent");
2504 nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2505 }
2506
2507 if (ProfileExceptionHandlers && trap_mdo != nullptr) {
2508 BitData* exception_handler_data = trap_mdo->exception_handler_bci_to_data_or_null(trap_bci);
2509 if (exception_handler_data != nullptr) {
2510 // uncommon trap at the start of an exception handler.
2511 // C2 generates these for un-entered exception handlers.
2512 // mark the handler as entered to avoid generating
2513 // another uncommon trap the next time the handler is compiled
2514 exception_handler_data->set_exception_handler_entered();
2515 }
2516 }
2517
2518 } // Free marked resources
2519
2520 }
2521 JRT_END
2522
2523 ProfileData*
2524 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2525 int trap_bci,
2526 Deoptimization::DeoptReason reason,
2527 bool update_total_trap_count,
2528 #if INCLUDE_JVMCI
2529 bool is_osr,
2530 #endif
2531 Method* compiled_method,
2532 //outputs:
2533 uint& ret_this_trap_count,
2534 bool& ret_maybe_prior_trap,
2535 bool& ret_maybe_prior_recompile) {
2536 trap_mdo->check_extra_data_locked();
2537
2538 bool maybe_prior_trap = false;
2539 bool maybe_prior_recompile = false;
2540 uint this_trap_count = 0;
2541 if (update_total_trap_count) {
2542 uint idx = reason;
2543 #if INCLUDE_JVMCI
2544 if (is_osr) {
2545 // Upper half of history array used for traps in OSR compilations
2546 idx += Reason_TRAP_HISTORY_LENGTH;
2547 }
2548 #endif
2549 uint prior_trap_count = trap_mdo->trap_count(idx);
2550 this_trap_count = trap_mdo->inc_trap_count(idx);
2551
2552 // If the runtime cannot find a place to store trap history,
2553 // it is estimated based on the general condition of the method.
2554 // If the method has ever been recompiled, or has ever incurred
2555 // a trap with the present reason , then this BCI is assumed
2556 // (pessimistically) to be the culprit.
2557 maybe_prior_trap = (prior_trap_count != 0);
2558 maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2559 }
2560 ProfileData* pdata = nullptr;
2561
2562
2563 // For reasons which are recorded per bytecode, we check per-BCI data.
2564 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2565 assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
2566 if (per_bc_reason != Reason_none) {
2567 // Find the profile data for this BCI. If there isn't one,
2568 // try to allocate one from the MDO's set of spares.
2569 // This will let us detect a repeated trap at this point.
2570 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : nullptr);
2571
2572 if (pdata != nullptr) {
2573 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2574 if (LogCompilation && xtty != nullptr) {
2575 ttyLocker ttyl;
2576 // no more room for speculative traps in this MDO
2577 xtty->elem("speculative_traps_oom");
2578 }
2579 }
2580 // Query the trap state of this profile datum.
2581 int tstate0 = pdata->trap_state();
2582 if (!trap_state_has_reason(tstate0, per_bc_reason))
2583 maybe_prior_trap = false;
2584 if (!trap_state_is_recompiled(tstate0))
2585 maybe_prior_recompile = false;
2586
2587 // Update the trap state of this profile datum.
2588 int tstate1 = tstate0;
2589 // Record the reason.
2590 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2591 // Store the updated state on the MDO, for next time.
2592 if (tstate1 != tstate0)
2593 pdata->set_trap_state(tstate1);
2594 } else {
2595 if (LogCompilation && xtty != nullptr) {
2596 ttyLocker ttyl;
2597 // Missing MDP? Leave a small complaint in the log.
2598 xtty->elem("missing_mdp bci='%d'", trap_bci);
2599 }
2600 }
2601 }
2602
2603 // Return results:
2604 ret_this_trap_count = this_trap_count;
2605 ret_maybe_prior_trap = maybe_prior_trap;
2606 ret_maybe_prior_recompile = maybe_prior_recompile;
2607 return pdata;
2608 }
2609
2610 void
2611 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2612 ResourceMark rm;
2613 // Ignored outputs:
2614 uint ignore_this_trap_count;
2615 bool ignore_maybe_prior_trap;
2616 bool ignore_maybe_prior_recompile;
2617 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2618 // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2619 bool update_total_counts = true JVMCI_ONLY( && !UseJVMCICompiler);
2620
2621 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2622 MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2623
2624 query_update_method_data(trap_mdo, trap_bci,
2625 (DeoptReason)reason,
2626 update_total_counts,
2627 #if INCLUDE_JVMCI
2628 false,
2629 #endif
2630 nullptr,
2631 ignore_this_trap_count,
2632 ignore_maybe_prior_trap,
2633 ignore_maybe_prior_recompile);
2634 }
2635
2636 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode) {
2637 // Enable WXWrite: current function is called from methods compiled by C2 directly
2638 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2639
2640 // Still in Java no safepoints
2641 {
2642 // This enters VM and may safepoint
2643 uncommon_trap_inner(current, trap_request);
2644 }
2645 HandleMark hm(current);
2646 return fetch_unroll_info_helper(current, exec_mode);
2647 }
2648
2649 // Local derived constants.
2650 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2651 const int DS_REASON_MASK = ((uint)DataLayout::trap_mask) >> 1;
2652 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2653
2654 //---------------------------trap_state_reason---------------------------------
2655 Deoptimization::DeoptReason
2656 Deoptimization::trap_state_reason(int trap_state) {
2657 // This assert provides the link between the width of DataLayout::trap_bits
2658 // and the encoding of "recorded" reasons. It ensures there are enough
2659 // bits to store all needed reasons in the per-BCI MDO profile.
2660 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2661 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2662 trap_state -= recompile_bit;
2663 if (trap_state == DS_REASON_MASK) {
2664 return Reason_many;
2665 } else {
2666 assert((int)Reason_none == 0, "state=0 => Reason_none");
2667 return (DeoptReason)trap_state;
2668 }
2669 }
2670 //-------------------------trap_state_has_reason-------------------------------
2671 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2672 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2673 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2674 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2675 trap_state -= recompile_bit;
2676 if (trap_state == DS_REASON_MASK) {
2677 return -1; // true, unspecifically (bottom of state lattice)
2678 } else if (trap_state == reason) {
2679 return 1; // true, definitely
2680 } else if (trap_state == 0) {
2681 return 0; // false, definitely (top of state lattice)
2682 } else {
2683 return 0; // false, definitely
2684 }
2685 }
2686 //-------------------------trap_state_add_reason-------------------------------
2687 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2688 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2689 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2690 trap_state -= recompile_bit;
2691 if (trap_state == DS_REASON_MASK) {
2692 return trap_state + recompile_bit; // already at state lattice bottom
2693 } else if (trap_state == reason) {
2694 return trap_state + recompile_bit; // the condition is already true
2695 } else if (trap_state == 0) {
2696 return reason + recompile_bit; // no condition has yet been true
2697 } else {
2698 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
2699 }
2700 }
2701 //-----------------------trap_state_is_recompiled------------------------------
2702 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2703 return (trap_state & DS_RECOMPILE_BIT) != 0;
2704 }
2705 //-----------------------trap_state_set_recompiled-----------------------------
2706 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2707 if (z) return trap_state | DS_RECOMPILE_BIT;
2708 else return trap_state & ~DS_RECOMPILE_BIT;
2709 }
2710 //---------------------------format_trap_state---------------------------------
2711 // This is used for debugging and diagnostics, including LogFile output.
2712 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2713 int trap_state) {
2714 assert(buflen > 0, "sanity");
2715 DeoptReason reason = trap_state_reason(trap_state);
2716 bool recomp_flag = trap_state_is_recompiled(trap_state);
2717 // Re-encode the state from its decoded components.
2718 int decoded_state = 0;
2719 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2720 decoded_state = trap_state_add_reason(decoded_state, reason);
2721 if (recomp_flag)
2722 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2723 // If the state re-encodes properly, format it symbolically.
2724 // Because this routine is used for debugging and diagnostics,
2725 // be robust even if the state is a strange value.
2726 size_t len;
2727 if (decoded_state != trap_state) {
2728 // Random buggy state that doesn't decode??
2729 len = jio_snprintf(buf, buflen, "#%d", trap_state);
2730 } else {
2731 len = jio_snprintf(buf, buflen, "%s%s",
2732 trap_reason_name(reason),
2733 recomp_flag ? " recompiled" : "");
2734 }
2735 return buf;
2736 }
2737
2738
2739 //--------------------------------statics--------------------------------------
2740 const char* Deoptimization::_trap_reason_name[] = {
2741 // Note: Keep this in sync. with enum DeoptReason.
2742 "none",
2743 "null_check",
2744 "null_assert" JVMCI_ONLY("_or_unreached0"),
2745 "range_check",
2746 "class_check",
2747 "array_check",
2748 "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2749 "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2750 "profile_predicate",
2751 "auto_vectorization_check",
2752 "unloaded",
2753 "uninitialized",
2754 "initialized",
2755 "unreached",
2756 "unhandled",
2757 "constraint",
2758 "div0_check",
2759 "age",
2760 "predicate",
2761 "loop_limit_check",
2762 "speculate_class_check",
2763 "speculate_null_check",
2764 "speculate_null_assert",
2765 "unstable_if",
2766 "unstable_fused_if",
2767 "receiver_constraint",
2768 "not_compiled_exception_handler",
2769 "short_running_loop" JVMCI_ONLY("_or_aliasing"),
2770 #if INCLUDE_JVMCI
2771 "transfer_to_interpreter",
2772 "unresolved",
2773 "jsr_mismatch",
2774 #endif
2775 "tenured"
2776 };
2777 const char* Deoptimization::_trap_action_name[] = {
2778 // Note: Keep this in sync. with enum DeoptAction.
2779 "none",
2780 "maybe_recompile",
2781 "reinterpret",
2782 "make_not_entrant",
2783 "make_not_compilable"
2784 };
2785
2786 const char* Deoptimization::trap_reason_name(int reason) {
2787 // Check that every reason has a name
2788 STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2789
2790 if (reason == Reason_many) return "many";
2791 if ((uint)reason < Reason_LIMIT)
2792 return _trap_reason_name[reason];
2793 static char buf[20];
2794 os::snprintf_checked(buf, sizeof(buf), "reason%d", reason);
2795 return buf;
2796 }
2797 const char* Deoptimization::trap_action_name(int action) {
2798 // Check that every action has a name
2799 STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2800
2801 if ((uint)action < Action_LIMIT)
2802 return _trap_action_name[action];
2803 static char buf[20];
2804 os::snprintf_checked(buf, sizeof(buf), "action%d", action);
2805 return buf;
2806 }
2807
2808 // This is used for debugging and diagnostics, including LogFile output.
2809 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2810 int trap_request) {
2811 jint unloaded_class_index = trap_request_index(trap_request);
2812 const char* reason = trap_reason_name(trap_request_reason(trap_request));
2813 const char* action = trap_action_name(trap_request_action(trap_request));
2814 #if INCLUDE_JVMCI
2815 int debug_id = trap_request_debug_id(trap_request);
2816 #endif
2817 size_t len;
2818 if (unloaded_class_index < 0) {
2819 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2820 reason, action
2821 #if INCLUDE_JVMCI
2822 ,debug_id
2823 #endif
2824 );
2825 } else {
2826 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2827 reason, action, unloaded_class_index
2828 #if INCLUDE_JVMCI
2829 ,debug_id
2830 #endif
2831 );
2832 }
2833 return buf;
2834 }
2835
2836 juint Deoptimization::_deoptimization_hist
2837 [Deoptimization::Reason_LIMIT]
2838 [1 + Deoptimization::Action_LIMIT]
2839 [Deoptimization::BC_CASE_LIMIT]
2840 = {0};
2841
2842 enum {
2843 LSB_BITS = 8,
2844 LSB_MASK = right_n_bits(LSB_BITS)
2845 };
2846
2847 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2848 Bytecodes::Code bc) {
2849 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2850 assert(action >= 0 && action < Action_LIMIT, "oob");
2851 _deoptimization_hist[Reason_none][0][0] += 1; // total
2852 _deoptimization_hist[reason][0][0] += 1; // per-reason total
2853 juint* cases = _deoptimization_hist[reason][1+action];
2854 juint* bc_counter_addr = nullptr;
2855 juint bc_counter = 0;
2856 // Look for an unused counter, or an exact match to this BC.
2857 if (bc != Bytecodes::_illegal) {
2858 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2859 juint* counter_addr = &cases[bc_case];
2860 juint counter = *counter_addr;
2861 if ((counter == 0 && bc_counter_addr == nullptr)
2862 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2863 // this counter is either free or is already devoted to this BC
2864 bc_counter_addr = counter_addr;
2865 bc_counter = counter | bc;
2866 }
2867 }
2868 }
2869 if (bc_counter_addr == nullptr) {
2870 // Overflow, or no given bytecode.
2871 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2872 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
2873 }
2874 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2875 }
2876
2877 jint Deoptimization::total_deoptimization_count() {
2878 return _deoptimization_hist[Reason_none][0][0];
2879 }
2880
2881 // Get the deopt count for a specific reason and a specific action. If either
2882 // one of 'reason' or 'action' is null, the method returns the sum of all
2883 // deoptimizations with the specific 'action' or 'reason' respectively.
2884 // If both arguments are null, the method returns the total deopt count.
2885 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2886 if (reason_str == nullptr && action_str == nullptr) {
2887 return total_deoptimization_count();
2888 }
2889 juint counter = 0;
2890 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2891 if (reason_str == nullptr || !strcmp(reason_str, trap_reason_name(reason))) {
2892 for (int action = 0; action < Action_LIMIT; action++) {
2893 if (action_str == nullptr || !strcmp(action_str, trap_action_name(action))) {
2894 juint* cases = _deoptimization_hist[reason][1+action];
2895 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2896 counter += cases[bc_case] >> LSB_BITS;
2897 }
2898 }
2899 }
2900 }
2901 }
2902 return counter;
2903 }
2904
2905 void Deoptimization::print_statistics() {
2906 juint total = total_deoptimization_count();
2907 juint account = total;
2908 if (total != 0) {
2909 ttyLocker ttyl;
2910 if (xtty != nullptr) xtty->head("statistics type='deoptimization'");
2911 tty->print_cr("Deoptimization traps recorded:");
2912 #define PRINT_STAT_LINE(name, r) \
2913 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2914 PRINT_STAT_LINE("total", total);
2915 // For each non-zero entry in the histogram, print the reason,
2916 // the action, and (if specifically known) the type of bytecode.
2917 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2918 for (int action = 0; action < Action_LIMIT; action++) {
2919 juint* cases = _deoptimization_hist[reason][1+action];
2920 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2921 juint counter = cases[bc_case];
2922 if (counter != 0) {
2923 char name[1*K];
2924 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2925 os::snprintf_checked(name, sizeof(name), "%s/%s/%s",
2926 trap_reason_name(reason),
2927 trap_action_name(action),
2928 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2929 juint r = counter >> LSB_BITS;
2930 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2931 account -= r;
2932 }
2933 }
2934 }
2935 }
2936 if (account != 0) {
2937 PRINT_STAT_LINE("unaccounted", account);
2938 }
2939 #undef PRINT_STAT_LINE
2940 if (xtty != nullptr) xtty->tail("statistics");
2941 }
2942 }
2943
2944 #else // COMPILER2_OR_JVMCI
2945
2946
2947 // Stubs for C1 only system.
2948 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2949 return false;
2950 }
2951
2952 const char* Deoptimization::trap_reason_name(int reason) {
2953 return "unknown";
2954 }
2955
2956 jint Deoptimization::total_deoptimization_count() {
2957 return 0;
2958 }
2959
2960 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2961 return 0;
2962 }
2963
2964 void Deoptimization::print_statistics() {
2965 // no output
2966 }
2967
2968 void
2969 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2970 // no update
2971 }
2972
2973 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2974 return 0;
2975 }
2976
2977 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2978 Bytecodes::Code bc) {
2979 // no update
2980 }
2981
2982 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2983 int trap_state) {
2984 jio_snprintf(buf, buflen, "#%d", trap_state);
2985 return buf;
2986 }
2987
2988 #endif // COMPILER2_OR_JVMCI
--- EOF ---