1 /*
2 * Copyright (c) 1997, 2024, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/javaClasses.inline.hpp"
27 #include "classfile/symbolTable.hpp"
28 #include "classfile/systemDictionary.hpp"
29 #include "classfile/vmClasses.hpp"
30 #include "code/codeCache.hpp"
31 #include "code/debugInfoRec.hpp"
32 #include "code/nmethod.hpp"
33 #include "code/pcDesc.hpp"
34 #include "code/scopeDesc.hpp"
35 #include "compiler/compilationPolicy.hpp"
36 #include "compiler/compilerDefinitions.inline.hpp"
37 #include "gc/shared/collectedHeap.hpp"
38 #include "gc/shared/memAllocator.hpp"
39 #include "interpreter/bytecode.hpp"
40 #include "interpreter/bytecodeStream.hpp"
41 #include "interpreter/interpreter.hpp"
42 #include "interpreter/oopMapCache.hpp"
43 #include "jvm.h"
44 #include "logging/log.hpp"
45 #include "logging/logLevel.hpp"
46 #include "logging/logMessage.hpp"
47 #include "logging/logStream.hpp"
48 #include "memory/allocation.inline.hpp"
49 #include "memory/oopFactory.hpp"
50 #include "memory/resourceArea.hpp"
51 #include "memory/universe.hpp"
52 #include "oops/constantPool.hpp"
53 #include "oops/fieldStreams.inline.hpp"
54 #include "oops/method.hpp"
55 #include "oops/objArrayKlass.hpp"
56 #include "oops/objArrayOop.inline.hpp"
57 #include "oops/oop.inline.hpp"
58 #include "oops/typeArrayOop.inline.hpp"
59 #include "oops/verifyOopClosure.hpp"
60 #include "prims/jvmtiDeferredUpdates.hpp"
61 #include "prims/jvmtiExport.hpp"
62 #include "prims/jvmtiThreadState.hpp"
63 #include "prims/methodHandles.hpp"
64 #include "prims/vectorSupport.hpp"
65 #include "runtime/atomic.hpp"
66 #include "runtime/basicLock.inline.hpp"
67 #include "runtime/continuation.hpp"
68 #include "runtime/continuationEntry.inline.hpp"
69 #include "runtime/deoptimization.hpp"
70 #include "runtime/escapeBarrier.hpp"
71 #include "runtime/fieldDescriptor.hpp"
72 #include "runtime/fieldDescriptor.inline.hpp"
73 #include "runtime/frame.inline.hpp"
74 #include "runtime/handles.inline.hpp"
75 #include "runtime/interfaceSupport.inline.hpp"
76 #include "runtime/javaThread.hpp"
77 #include "runtime/jniHandles.inline.hpp"
78 #include "runtime/keepStackGCProcessed.hpp"
79 #include "runtime/lightweightSynchronizer.hpp"
80 #include "runtime/lockStack.inline.hpp"
81 #include "runtime/objectMonitor.inline.hpp"
82 #include "runtime/osThread.hpp"
83 #include "runtime/safepointVerifiers.hpp"
84 #include "runtime/sharedRuntime.hpp"
85 #include "runtime/signature.hpp"
86 #include "runtime/stackFrameStream.inline.hpp"
87 #include "runtime/stackValue.hpp"
88 #include "runtime/stackWatermarkSet.hpp"
89 #include "runtime/stubRoutines.hpp"
90 #include "runtime/synchronizer.inline.hpp"
91 #include "runtime/threadSMR.hpp"
92 #include "runtime/threadWXSetters.inline.hpp"
93 #include "runtime/vframe.hpp"
94 #include "runtime/vframeArray.hpp"
95 #include "runtime/vframe_hp.hpp"
96 #include "runtime/vmOperations.hpp"
97 #include "utilities/checkedCast.hpp"
98 #include "utilities/events.hpp"
99 #include "utilities/growableArray.hpp"
100 #include "utilities/macros.hpp"
101 #include "utilities/preserveException.hpp"
102 #include "utilities/xmlstream.hpp"
103 #if INCLUDE_JFR
104 #include "jfr/jfrEvents.hpp"
105 #include "jfr/metadata/jfrSerializer.hpp"
106 #endif
107
108 uint64_t DeoptimizationScope::_committed_deopt_gen = 0;
109 uint64_t DeoptimizationScope::_active_deopt_gen = 1;
110 bool DeoptimizationScope::_committing_in_progress = false;
111
112 DeoptimizationScope::DeoptimizationScope() : _required_gen(0) {
113 DEBUG_ONLY(_deopted = false;)
114
115 MutexLocker ml(NMethodState_lock, Mutex::_no_safepoint_check_flag);
116 // If there is nothing to deopt _required_gen is the same as comitted.
117 _required_gen = DeoptimizationScope::_committed_deopt_gen;
118 }
119
120 DeoptimizationScope::~DeoptimizationScope() {
121 assert(_deopted, "Deopt not executed");
122 }
123
124 void DeoptimizationScope::mark(nmethod* nm, bool inc_recompile_counts) {
125 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
126
127 // If it's already marked but we still need it to be deopted.
128 if (nm->is_marked_for_deoptimization()) {
129 dependent(nm);
130 return;
131 }
132
133 nmethod::DeoptimizationStatus status =
134 inc_recompile_counts ? nmethod::deoptimize : nmethod::deoptimize_noupdate;
135 Atomic::store(&nm->_deoptimization_status, status);
136
137 // Make sure active is not committed
138 assert(DeoptimizationScope::_committed_deopt_gen < DeoptimizationScope::_active_deopt_gen, "Must be");
139 assert(nm->_deoptimization_generation == 0, "Is already marked");
140
141 nm->_deoptimization_generation = DeoptimizationScope::_active_deopt_gen;
142 _required_gen = DeoptimizationScope::_active_deopt_gen;
143 }
144
145 void DeoptimizationScope::dependent(nmethod* nm) {
146 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
147
148 // A method marked by someone else may have a _required_gen lower than what we marked with.
149 // Therefore only store it if it's higher than _required_gen.
150 if (_required_gen < nm->_deoptimization_generation) {
151 _required_gen = nm->_deoptimization_generation;
152 }
153 }
154
155 void DeoptimizationScope::deoptimize_marked() {
156 assert(!_deopted, "Already deopted");
157
158 // We are not alive yet.
159 if (!Universe::is_fully_initialized()) {
160 DEBUG_ONLY(_deopted = true;)
161 return;
162 }
163
164 // Safepoints are a special case, handled here.
165 if (SafepointSynchronize::is_at_safepoint()) {
166 DeoptimizationScope::_committed_deopt_gen = DeoptimizationScope::_active_deopt_gen;
167 DeoptimizationScope::_active_deopt_gen++;
168 Deoptimization::deoptimize_all_marked();
169 DEBUG_ONLY(_deopted = true;)
170 return;
171 }
172
173 uint64_t comitting = 0;
174 bool wait = false;
175 while (true) {
176 {
177 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
178
179 // First we check if we or someone else already deopted the gen we want.
180 if (DeoptimizationScope::_committed_deopt_gen >= _required_gen) {
181 DEBUG_ONLY(_deopted = true;)
182 return;
183 }
184 if (!_committing_in_progress) {
185 // The version we are about to commit.
186 comitting = DeoptimizationScope::_active_deopt_gen;
187 // Make sure new marks use a higher gen.
188 DeoptimizationScope::_active_deopt_gen++;
189 _committing_in_progress = true;
190 wait = false;
191 } else {
192 // Another thread is handshaking and committing a gen.
193 wait = true;
194 }
195 }
196 if (wait) {
197 // Wait and let the concurrent handshake be performed.
198 ThreadBlockInVM tbivm(JavaThread::current());
199 os::naked_yield();
200 } else {
201 // Performs the handshake.
202 Deoptimization::deoptimize_all_marked(); // May safepoint and an additional deopt may have occurred.
203 DEBUG_ONLY(_deopted = true;)
204 {
205 ConditionalMutexLocker ml(NMethodState_lock, !NMethodState_lock->owned_by_self(), Mutex::_no_safepoint_check_flag);
206
207 // Make sure that committed doesn't go backwards.
208 // Should only happen if we did a deopt during a safepoint above.
209 if (DeoptimizationScope::_committed_deopt_gen < comitting) {
210 DeoptimizationScope::_committed_deopt_gen = comitting;
211 }
212 _committing_in_progress = false;
213
214 assert(DeoptimizationScope::_committed_deopt_gen >= _required_gen, "Must be");
215
216 return;
217 }
218 }
219 }
220 }
221
222 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
223 int caller_adjustment,
224 int caller_actual_parameters,
225 int number_of_frames,
226 intptr_t* frame_sizes,
227 address* frame_pcs,
228 BasicType return_type,
229 int exec_mode) {
230 _size_of_deoptimized_frame = size_of_deoptimized_frame;
231 _caller_adjustment = caller_adjustment;
232 _caller_actual_parameters = caller_actual_parameters;
233 _number_of_frames = number_of_frames;
234 _frame_sizes = frame_sizes;
235 _frame_pcs = frame_pcs;
236 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
237 _return_type = return_type;
238 _initial_info = 0;
239 // PD (x86 only)
240 _counter_temp = 0;
241 _unpack_kind = exec_mode;
242 _sender_sp_temp = 0;
243
244 _total_frame_sizes = size_of_frames();
245 assert(exec_mode >= 0 && exec_mode < Unpack_LIMIT, "Unexpected exec_mode");
246 }
247
248 Deoptimization::UnrollBlock::~UnrollBlock() {
249 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
250 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
251 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
252 }
253
254 int Deoptimization::UnrollBlock::size_of_frames() const {
255 // Account first for the adjustment of the initial frame
256 intptr_t result = _caller_adjustment;
257 for (int index = 0; index < number_of_frames(); index++) {
258 result += frame_sizes()[index];
259 }
260 return checked_cast<int>(result);
261 }
262
263 void Deoptimization::UnrollBlock::print() {
264 ResourceMark rm;
265 stringStream st;
266 st.print_cr("UnrollBlock");
267 st.print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
268 st.print( " frame_sizes: ");
269 for (int index = 0; index < number_of_frames(); index++) {
270 st.print(INTX_FORMAT " ", frame_sizes()[index]);
271 }
272 st.cr();
273 tty->print_raw(st.freeze());
274 }
275
276 // In order to make fetch_unroll_info work properly with escape
277 // analysis, the method was changed from JRT_LEAF to JRT_BLOCK_ENTRY.
278 // The actual reallocation of previously eliminated objects occurs in realloc_objects,
279 // which is called from the method fetch_unroll_info_helper below.
280 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* current, int exec_mode))
281 // fetch_unroll_info() is called at the beginning of the deoptimization
282 // handler. Note this fact before we start generating temporary frames
283 // that can confuse an asynchronous stack walker. This counter is
284 // decremented at the end of unpack_frames().
285 current->inc_in_deopt_handler();
286
287 if (exec_mode == Unpack_exception) {
288 // When we get here, a callee has thrown an exception into a deoptimized
289 // frame. That throw might have deferred stack watermark checking until
290 // after unwinding. So we deal with such deferred requests here.
291 StackWatermarkSet::after_unwind(current);
292 }
293
294 return fetch_unroll_info_helper(current, exec_mode);
295 JRT_END
296
297 #if COMPILER2_OR_JVMCI
298 // print information about reallocated objects
299 static void print_objects(JavaThread* deoptee_thread,
300 GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
301 ResourceMark rm;
302 stringStream st; // change to logStream with logging
303 st.print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(deoptee_thread));
304 fieldDescriptor fd;
305
306 for (int i = 0; i < objects->length(); i++) {
307 ObjectValue* sv = (ObjectValue*) objects->at(i);
308 Handle obj = sv->value();
309
310 if (obj.is_null()) {
311 st.print_cr(" nullptr");
312 continue;
313 }
314
315 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
316
317 st.print(" object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
318 k->print_value_on(&st);
319 st.print_cr(" allocated (" SIZE_FORMAT " bytes)", obj->size() * HeapWordSize);
320
321 if (Verbose && k != nullptr) {
322 k->oop_print_on(obj(), &st);
323 }
324 }
325 tty->print_raw(st.freeze());
326 }
327
328 static bool rematerialize_objects(JavaThread* thread, int exec_mode, nmethod* compiled_method,
329 frame& deoptee, RegisterMap& map, GrowableArray<compiledVFrame*>* chunk,
330 bool& deoptimized_objects) {
331 bool realloc_failures = false;
332 assert (chunk->at(0)->scope() != nullptr,"expect only compiled java frames");
333
334 JavaThread* deoptee_thread = chunk->at(0)->thread();
335 assert(exec_mode == Deoptimization::Unpack_none || (deoptee_thread == thread),
336 "a frame can only be deoptimized by the owner thread");
337
338 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects_to_rematerialize(deoptee, map);
339
340 // The flag return_oop() indicates call sites which return oop
341 // in compiled code. Such sites include java method calls,
342 // runtime calls (for example, used to allocate new objects/arrays
343 // on slow code path) and any other calls generated in compiled code.
344 // It is not guaranteed that we can get such information here only
345 // by analyzing bytecode in deoptimized frames. This is why this flag
346 // is set during method compilation (see Compile::Process_OopMap_Node()).
347 // If the previous frame was popped or if we are dispatching an exception,
348 // we don't have an oop result.
349 bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution() && (exec_mode == Deoptimization::Unpack_deopt);
350 Handle return_value;
351 if (save_oop_result) {
352 // Reallocation may trigger GC. If deoptimization happened on return from
353 // call which returns oop we need to save it since it is not in oopmap.
354 oop result = deoptee.saved_oop_result(&map);
355 assert(oopDesc::is_oop_or_null(result), "must be oop");
356 return_value = Handle(thread, result);
357 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
358 if (TraceDeoptimization) {
359 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
360 tty->cr();
361 }
362 }
363 if (objects != nullptr) {
364 if (exec_mode == Deoptimization::Unpack_none) {
365 assert(thread->thread_state() == _thread_in_vm, "assumption");
366 JavaThread* THREAD = thread; // For exception macros.
367 // Clear pending OOM if reallocation fails and return true indicating allocation failure
368 realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, CHECK_AND_CLEAR_(true));
369 deoptimized_objects = true;
370 } else {
371 JavaThread* current = thread; // For JRT_BLOCK
372 JRT_BLOCK
373 realloc_failures = Deoptimization::realloc_objects(thread, &deoptee, &map, objects, THREAD);
374 JRT_END
375 }
376 bool skip_internal = (compiled_method != nullptr) && !compiled_method->is_compiled_by_jvmci();
377 Deoptimization::reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal);
378 if (TraceDeoptimization) {
379 print_objects(deoptee_thread, objects, realloc_failures);
380 }
381 }
382 if (save_oop_result) {
383 // Restore result.
384 deoptee.set_saved_oop_result(&map, return_value());
385 }
386 return realloc_failures;
387 }
388
389 static void restore_eliminated_locks(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures,
390 frame& deoptee, int exec_mode, bool& deoptimized_objects) {
391 JavaThread* deoptee_thread = chunk->at(0)->thread();
392 assert(!EscapeBarrier::objs_are_deoptimized(deoptee_thread, deoptee.id()), "must relock just once");
393 assert(thread == Thread::current(), "should be");
394 HandleMark hm(thread);
395 #ifndef PRODUCT
396 bool first = true;
397 #endif // !PRODUCT
398 // Start locking from outermost/oldest frame
399 for (int i = (chunk->length() - 1); i >= 0; i--) {
400 compiledVFrame* cvf = chunk->at(i);
401 assert (cvf->scope() != nullptr,"expect only compiled java frames");
402 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
403 if (monitors->is_nonempty()) {
404 bool relocked = Deoptimization::relock_objects(thread, monitors, deoptee_thread, deoptee,
405 exec_mode, realloc_failures);
406 deoptimized_objects = deoptimized_objects || relocked;
407 #ifndef PRODUCT
408 if (PrintDeoptimizationDetails) {
409 ResourceMark rm;
410 stringStream st;
411 for (int j = 0; j < monitors->length(); j++) {
412 MonitorInfo* mi = monitors->at(j);
413 if (mi->eliminated()) {
414 if (first) {
415 first = false;
416 st.print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
417 }
418 if (exec_mode == Deoptimization::Unpack_none) {
419 ObjectMonitor* monitor = deoptee_thread->current_waiting_monitor();
420 if (monitor != nullptr && monitor->object() == mi->owner()) {
421 st.print_cr(" object <" INTPTR_FORMAT "> DEFERRED relocking after wait", p2i(mi->owner()));
422 continue;
423 }
424 }
425 if (mi->owner_is_scalar_replaced()) {
426 Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
427 st.print_cr(" failed reallocation for klass %s", k->external_name());
428 } else {
429 st.print_cr(" object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
430 }
431 }
432 }
433 tty->print_raw(st.freeze());
434 }
435 #endif // !PRODUCT
436 }
437 }
438 }
439
440 // Deoptimize objects, that is reallocate and relock them, just before they escape through JVMTI.
441 // The given vframes cover one physical frame.
442 bool Deoptimization::deoptimize_objects_internal(JavaThread* thread, GrowableArray<compiledVFrame*>* chunk,
443 bool& realloc_failures) {
444 frame deoptee = chunk->at(0)->fr();
445 JavaThread* deoptee_thread = chunk->at(0)->thread();
446 nmethod* nm = deoptee.cb()->as_nmethod_or_null();
447 RegisterMap map(chunk->at(0)->register_map());
448 bool deoptimized_objects = false;
449
450 bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
451
452 // Reallocate the non-escaping objects and restore their fields.
453 if (jvmci_enabled COMPILER2_PRESENT(|| (DoEscapeAnalysis && EliminateAllocations)
454 || EliminateAutoBox || EnableVectorAggressiveReboxing)) {
455 realloc_failures = rematerialize_objects(thread, Unpack_none, nm, deoptee, map, chunk, deoptimized_objects);
456 }
457
458 // MonitorInfo structures used in eliminate_locks are not GC safe.
459 NoSafepointVerifier no_safepoint;
460
461 // Now relock objects if synchronization on them was eliminated.
462 if (jvmci_enabled COMPILER2_PRESENT(|| ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks))) {
463 restore_eliminated_locks(thread, chunk, realloc_failures, deoptee, Unpack_none, deoptimized_objects);
464 }
465 return deoptimized_objects;
466 }
467 #endif // COMPILER2_OR_JVMCI
468
469 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
470 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* current, int exec_mode) {
471 // When we get here we are about to unwind the deoptee frame. In order to
472 // catch not yet safe to use frames, the following stack watermark barrier
473 // poll will make such frames safe to use.
474 StackWatermarkSet::before_unwind(current);
475
476 // Note: there is a safepoint safety issue here. No matter whether we enter
477 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
478 // the vframeArray is created.
479 //
480
481 // Allocate our special deoptimization ResourceMark
482 DeoptResourceMark* dmark = new DeoptResourceMark(current);
483 assert(current->deopt_mark() == nullptr, "Pending deopt!");
484 current->set_deopt_mark(dmark);
485
486 frame stub_frame = current->last_frame(); // Makes stack walkable as side effect
487 RegisterMap map(current,
488 RegisterMap::UpdateMap::include,
489 RegisterMap::ProcessFrames::include,
490 RegisterMap::WalkContinuation::skip);
491 RegisterMap dummy_map(current,
492 RegisterMap::UpdateMap::skip,
493 RegisterMap::ProcessFrames::include,
494 RegisterMap::WalkContinuation::skip);
495 // Now get the deoptee with a valid map
496 frame deoptee = stub_frame.sender(&map);
497 // Set the deoptee nmethod
498 assert(current->deopt_compiled_method() == nullptr, "Pending deopt!");
499 nmethod* nm = deoptee.cb()->as_nmethod_or_null();
500 current->set_deopt_compiled_method(nm);
501
502 if (VerifyStack) {
503 current->validate_frame_layout();
504 }
505
506 // Create a growable array of VFrames where each VFrame represents an inlined
507 // Java frame. This storage is allocated with the usual system arena.
508 assert(deoptee.is_compiled_frame(), "Wrong frame type");
509 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
510 vframe* vf = vframe::new_vframe(&deoptee, &map, current);
511 while (!vf->is_top()) {
512 assert(vf->is_compiled_frame(), "Wrong frame type");
513 chunk->push(compiledVFrame::cast(vf));
514 vf = vf->sender();
515 }
516 assert(vf->is_compiled_frame(), "Wrong frame type");
517 chunk->push(compiledVFrame::cast(vf));
518
519 bool realloc_failures = false;
520
521 #if COMPILER2_OR_JVMCI
522 bool const jvmci_enabled = JVMCI_ONLY(EnableJVMCI) NOT_JVMCI(false);
523
524 // Reallocate the non-escaping objects and restore their fields. Then
525 // relock objects if synchronization on them was eliminated.
526 if (jvmci_enabled COMPILER2_PRESENT( || (DoEscapeAnalysis && EliminateAllocations)
527 || EliminateAutoBox || EnableVectorAggressiveReboxing )) {
528 bool unused;
529 realloc_failures = rematerialize_objects(current, exec_mode, nm, deoptee, map, chunk, unused);
530 }
531 #endif // COMPILER2_OR_JVMCI
532
533 // Ensure that no safepoint is taken after pointers have been stored
534 // in fields of rematerialized objects. If a safepoint occurs from here on
535 // out the java state residing in the vframeArray will be missed.
536 // Locks may be rebaised in a safepoint.
537 NoSafepointVerifier no_safepoint;
538
539 #if COMPILER2_OR_JVMCI
540 if ((jvmci_enabled COMPILER2_PRESENT( || ((DoEscapeAnalysis || EliminateNestedLocks) && EliminateLocks) ))
541 && !EscapeBarrier::objs_are_deoptimized(current, deoptee.id())) {
542 bool unused = false;
543 restore_eliminated_locks(current, chunk, realloc_failures, deoptee, exec_mode, unused);
544 }
545 #endif // COMPILER2_OR_JVMCI
546
547 ScopeDesc* trap_scope = chunk->at(0)->scope();
548 Handle exceptionObject;
549 if (trap_scope->rethrow_exception()) {
550 #ifndef PRODUCT
551 if (PrintDeoptimizationDetails) {
552 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());
553 }
554 #endif // !PRODUCT
555
556 GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
557 guarantee(expressions != nullptr && expressions->length() > 0, "must have exception to throw");
558 ScopeValue* topOfStack = expressions->top();
559 exceptionObject = StackValue::create_stack_value(&deoptee, &map, topOfStack)->get_obj();
560 guarantee(exceptionObject() != nullptr, "exception oop can not be null");
561 }
562
563 vframeArray* array = create_vframeArray(current, deoptee, &map, chunk, realloc_failures);
564 #if COMPILER2_OR_JVMCI
565 if (realloc_failures) {
566 // This destroys all ScopedValue bindings.
567 current->clear_scopedValueBindings();
568 pop_frames_failed_reallocs(current, array);
569 }
570 #endif
571
572 assert(current->vframe_array_head() == nullptr, "Pending deopt!");
573 current->set_vframe_array_head(array);
574
575 // Now that the vframeArray has been created if we have any deferred local writes
576 // added by jvmti then we can free up that structure as the data is now in the
577 // vframeArray
578
579 JvmtiDeferredUpdates::delete_updates_for_frame(current, array->original().id());
580
581 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
582 CodeBlob* cb = stub_frame.cb();
583 // Verify we have the right vframeArray
584 assert(cb->frame_size() >= 0, "Unexpected frame size");
585 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
586
587 // If the deopt call site is a MethodHandle invoke call site we have
588 // to adjust the unpack_sp.
589 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
590 if (deoptee_nm != nullptr && deoptee_nm->is_method_handle_return(deoptee.pc()))
591 unpack_sp = deoptee.unextended_sp();
592
593 #ifdef ASSERT
594 assert(cb->is_deoptimization_stub() ||
595 cb->is_uncommon_trap_stub() ||
596 strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
597 strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
598 "unexpected code blob: %s", cb->name());
599 #endif
600
601 // This is a guarantee instead of an assert because if vframe doesn't match
602 // we will unpack the wrong deoptimized frame and wind up in strange places
603 // where it will be very difficult to figure out what went wrong. Better
604 // to die an early death here than some very obscure death later when the
605 // trail is cold.
606 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
607 // in that it will fail to detect a problem when there is one. This needs
608 // more work in tiger timeframe.
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 = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
645 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
646 // Method handle invokes may involve fairly arbitrary chains of
647 // calls so it's impossible to know how much actual space the
648 // caller has for locals.
649 caller_was_method_handle = true;
650 }
651 }
652
653 //
654 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
655 // frame_sizes/frame_pcs[1] next oldest frame (int)
656 // frame_sizes/frame_pcs[n] youngest frame (int)
657 //
658 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
659 // owns the space for the return address to it's caller). Confusing ain't it.
660 //
661 // The vframe array can address vframes with indices running from
662 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
663 // When we create the skeletal frames we need the oldest frame to be in the zero slot
664 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
665 // so things look a little strange in this loop.
666 //
667 int callee_parameters = 0;
668 int callee_locals = 0;
669 for (int index = 0; index < array->frames(); index++ ) {
670 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
671 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
672 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
673 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
674 callee_locals,
675 index == 0,
676 popframe_extra_args);
677 // This pc doesn't have to be perfect just good enough to identify the frame
678 // as interpreted so the skeleton frame will be walkable
679 // The correct pc will be set when the skeleton frame is completely filled out
680 // The final pc we store in the loop is wrong and will be overwritten below
681 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
682
683 callee_parameters = array->element(index)->method()->size_of_parameters();
684 callee_locals = array->element(index)->method()->max_locals();
685 popframe_extra_args = 0;
686 }
687
688 // Compute whether the root vframe returns a float or double value.
689 BasicType return_type;
690 {
691 methodHandle method(current, array->element(0)->method());
692 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
693 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
694 }
695
696 // Compute information for handling adapters and adjusting the frame size of the caller.
697 int caller_adjustment = 0;
698
699 // Compute the amount the oldest interpreter frame will have to adjust
700 // its caller's stack by. If the caller is a compiled frame then
701 // we pretend that the callee has no parameters so that the
702 // extension counts for the full amount of locals and not just
703 // locals-parms. This is because without a c2i adapter the parm
704 // area as created by the compiled frame will not be usable by
705 // the interpreter. (Depending on the calling convention there
706 // may not even be enough space).
707
708 // QQQ I'd rather see this pushed down into last_frame_adjust
709 // and have it take the sender (aka caller).
710
711 if (!deopt_sender.is_interpreted_frame() || caller_was_method_handle) {
712 caller_adjustment = last_frame_adjust(0, callee_locals);
713 } else if (callee_locals > callee_parameters) {
714 // The caller frame may need extending to accommodate
715 // non-parameter locals of the first unpacked interpreted frame.
716 // Compute that adjustment.
717 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
718 }
719
720 // If the sender is deoptimized the we must retrieve the address of the handler
721 // since the frame will "magically" show the original pc before the deopt
722 // and we'd undo the deopt.
723
724 frame_pcs[0] = Continuation::is_cont_barrier_frame(deoptee) ? StubRoutines::cont_returnBarrier() : deopt_sender.raw_pc();
725 if (Continuation::is_continuation_enterSpecial(deopt_sender)) {
726 ContinuationEntry::from_frame(deopt_sender)->set_argsize(0);
727 }
728
729 assert(CodeCache::find_blob(frame_pcs[0]) != nullptr, "bad pc");
730
731 #if INCLUDE_JVMCI
732 if (exceptionObject() != nullptr) {
733 current->set_exception_oop(exceptionObject());
734 exec_mode = Unpack_exception;
735 }
736 #endif
737
738 if (current->frames_to_pop_failed_realloc() > 0 && exec_mode != Unpack_uncommon_trap) {
739 assert(current->has_pending_exception(), "should have thrown OOME");
740 current->set_exception_oop(current->pending_exception());
741 current->clear_pending_exception();
742 exec_mode = Unpack_exception;
743 }
744
745 #if INCLUDE_JVMCI
746 if (current->frames_to_pop_failed_realloc() > 0) {
747 current->set_pending_monitorenter(false);
748 }
749 #endif
750
751 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
752 caller_adjustment * BytesPerWord,
753 caller_was_method_handle ? 0 : callee_parameters,
754 number_of_frames,
755 frame_sizes,
756 frame_pcs,
757 return_type,
758 exec_mode);
759 // On some platforms, we need a way to pass some platform dependent
760 // information to the unpacking code so the skeletal frames come out
761 // correct (initial fp value, unextended sp, ...)
762 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
763
764 if (array->frames() > 1) {
765 if (VerifyStack && TraceDeoptimization) {
766 tty->print_cr("Deoptimizing method containing inlining");
767 }
768 }
769
770 array->set_unroll_block(info);
771 return info;
772 }
773
774 // Called to cleanup deoptimization data structures in normal case
775 // after unpacking to stack and when stack overflow error occurs
776 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
777 vframeArray *array) {
778
779 // Get array if coming from exception
780 if (array == nullptr) {
781 array = thread->vframe_array_head();
782 }
783 thread->set_vframe_array_head(nullptr);
784
785 // Free the previous UnrollBlock
786 vframeArray* old_array = thread->vframe_array_last();
787 thread->set_vframe_array_last(array);
788
789 if (old_array != nullptr) {
790 UnrollBlock* old_info = old_array->unroll_block();
791 old_array->set_unroll_block(nullptr);
792 delete old_info;
793 delete old_array;
794 }
795
796 // Deallocate any resource creating in this routine and any ResourceObjs allocated
797 // inside the vframeArray (StackValueCollections)
798
799 delete thread->deopt_mark();
800 thread->set_deopt_mark(nullptr);
801 thread->set_deopt_compiled_method(nullptr);
802
803
804 if (JvmtiExport::can_pop_frame()) {
805 // Regardless of whether we entered this routine with the pending
806 // popframe condition bit set, we should always clear it now
807 thread->clear_popframe_condition();
808 }
809
810 // unpack_frames() is called at the end of the deoptimization handler
811 // and (in C2) at the end of the uncommon trap handler. Note this fact
812 // so that an asynchronous stack walker can work again. This counter is
813 // incremented at the beginning of fetch_unroll_info() and (in C2) at
814 // the beginning of uncommon_trap().
815 thread->dec_in_deopt_handler();
816 }
817
818 // Moved from cpu directories because none of the cpus has callee save values.
819 // If a cpu implements callee save values, move this to deoptimization_<cpu>.cpp.
820 void Deoptimization::unwind_callee_save_values(frame* f, vframeArray* vframe_array) {
821
822 // This code is sort of the equivalent of C2IAdapter::setup_stack_frame back in
823 // the days we had adapter frames. When we deoptimize a situation where a
824 // compiled caller calls a compiled caller will have registers it expects
825 // to survive the call to the callee. If we deoptimize the callee the only
826 // way we can restore these registers is to have the oldest interpreter
827 // frame that we create restore these values. That is what this routine
828 // will accomplish.
829
830 // At the moment we have modified c2 to not have any callee save registers
831 // so this problem does not exist and this routine is just a place holder.
832
833 assert(f->is_interpreted_frame(), "must be interpreted");
834 }
835
836 #ifndef PRODUCT
837 static bool falls_through(Bytecodes::Code bc) {
838 switch (bc) {
839 // List may be incomplete. Here we really only care about bytecodes where compiled code
840 // can deoptimize.
841 case Bytecodes::_goto:
842 case Bytecodes::_goto_w:
843 case Bytecodes::_athrow:
844 return false;
845 default:
846 return true;
847 }
848 }
849 #endif
850
851 // Return BasicType of value being returned
852 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
853 assert(thread == JavaThread::current(), "pre-condition");
854
855 // We are already active in the special DeoptResourceMark any ResourceObj's we
856 // allocate will be freed at the end of the routine.
857
858 // JRT_LEAF methods don't normally allocate handles and there is a
859 // NoHandleMark to enforce that. It is actually safe to use Handles
860 // in a JRT_LEAF method, and sometimes desirable, but to do so we
861 // must use ResetNoHandleMark to bypass the NoHandleMark, and
862 // then use a HandleMark to ensure any Handles we do create are
863 // cleaned up in this scope.
864 ResetNoHandleMark rnhm;
865 HandleMark hm(thread);
866
867 frame stub_frame = thread->last_frame();
868
869 Continuation::notify_deopt(thread, stub_frame.sp());
870
871 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
872 // must point to the vframeArray for the unpack frame.
873 vframeArray* array = thread->vframe_array_head();
874 UnrollBlock* info = array->unroll_block();
875
876 // We set the last_Java frame. But the stack isn't really parsable here. So we
877 // clear it to make sure JFR understands not to try and walk stacks from events
878 // in here.
879 intptr_t* sp = thread->frame_anchor()->last_Java_sp();
880 thread->frame_anchor()->set_last_Java_sp(nullptr);
881
882 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
883 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
884
885 thread->frame_anchor()->set_last_Java_sp(sp);
886
887 BasicType bt = info->return_type();
888
889 // If we have an exception pending, claim that the return type is an oop
890 // so the deopt_blob does not overwrite the exception_oop.
891
892 if (exec_mode == Unpack_exception)
893 bt = T_OBJECT;
894
895 // Cleanup thread deopt data
896 cleanup_deopt_info(thread, array);
897
898 #ifndef PRODUCT
899 if (VerifyStack) {
900 ResourceMark res_mark;
901 // Clear pending exception to not break verification code (restored afterwards)
902 PreserveExceptionMark pm(thread);
903
904 thread->validate_frame_layout();
905
906 // Verify that the just-unpacked frames match the interpreter's
907 // notions of expression stack and locals
908 vframeArray* cur_array = thread->vframe_array_last();
909 RegisterMap rm(thread,
910 RegisterMap::UpdateMap::skip,
911 RegisterMap::ProcessFrames::include,
912 RegisterMap::WalkContinuation::skip);
913 rm.set_include_argument_oops(false);
914 bool is_top_frame = true;
915 int callee_size_of_parameters = 0;
916 int callee_max_locals = 0;
917 for (int i = 0; i < cur_array->frames(); i++) {
918 vframeArrayElement* el = cur_array->element(i);
919 frame* iframe = el->iframe();
920 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
921
922 // Get the oop map for this bci
923 InterpreterOopMap mask;
924 int cur_invoke_parameter_size = 0;
925 bool try_next_mask = false;
926 int next_mask_expression_stack_size = -1;
927 int top_frame_expression_stack_adjustment = 0;
928 methodHandle mh(thread, iframe->interpreter_frame_method());
929 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
930 BytecodeStream str(mh, iframe->interpreter_frame_bci());
931 int max_bci = mh->code_size();
932 // Get to the next bytecode if possible
933 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
934 // Check to see if we can grab the number of outgoing arguments
935 // at an uncommon trap for an invoke (where the compiler
936 // generates debug info before the invoke has executed)
937 Bytecodes::Code cur_code = str.next();
938 Bytecodes::Code next_code = Bytecodes::_shouldnotreachhere;
939 if (Bytecodes::is_invoke(cur_code)) {
940 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
941 cur_invoke_parameter_size = invoke.size_of_parameters();
942 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
943 callee_size_of_parameters++;
944 }
945 }
946 if (str.bci() < max_bci) {
947 next_code = str.next();
948 if (next_code >= 0) {
949 // The interpreter oop map generator reports results before
950 // the current bytecode has executed except in the case of
951 // calls. It seems to be hard to tell whether the compiler
952 // has emitted debug information matching the "state before"
953 // a given bytecode or the state after, so we try both
954 if (!Bytecodes::is_invoke(cur_code) && falls_through(cur_code)) {
955 // Get expression stack size for the next bytecode
956 InterpreterOopMap next_mask;
957 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
958 next_mask_expression_stack_size = next_mask.expression_stack_size();
959 if (Bytecodes::is_invoke(next_code)) {
960 Bytecode_invoke invoke(mh, str.bci());
961 next_mask_expression_stack_size += invoke.size_of_parameters();
962 }
963 // Need to subtract off the size of the result type of
964 // the bytecode because this is not described in the
965 // debug info but returned to the interpreter in the TOS
966 // caching register
967 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
968 if (bytecode_result_type != T_ILLEGAL) {
969 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
970 }
971 assert(top_frame_expression_stack_adjustment >= 0, "stack adjustment must be positive");
972 try_next_mask = true;
973 }
974 }
975 }
976
977 // Verify stack depth and oops in frame
978 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
979 if (!(
980 /* SPARC */
981 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
982 /* x86 */
983 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
984 (try_next_mask &&
985 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
986 top_frame_expression_stack_adjustment))) ||
987 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
988 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
989 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
990 )) {
991 {
992 // Print out some information that will help us debug the problem
993 tty->print_cr("Wrong number of expression stack elements during deoptimization");
994 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
995 tty->print_cr(" Current code %s", Bytecodes::name(cur_code));
996 if (try_next_mask) {
997 tty->print_cr(" Next code %s", Bytecodes::name(next_code));
998 }
999 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
1000 iframe->interpreter_frame_expression_stack_size());
1001 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
1002 tty->print_cr(" try_next_mask = %d", try_next_mask);
1003 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
1004 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
1005 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
1006 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
1007 tty->print_cr(" exec_mode = %d", exec_mode);
1008 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
1009 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
1010 tty->print_cr(" Interpreted frames:");
1011 for (int k = 0; k < cur_array->frames(); k++) {
1012 vframeArrayElement* el = cur_array->element(k);
1013 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
1014 }
1015 cur_array->print_on_2(tty);
1016 }
1017 guarantee(false, "wrong number of expression stack elements during deopt");
1018 }
1019 VerifyOopClosure verify;
1020 iframe->oops_interpreted_do(&verify, &rm, false);
1021 callee_size_of_parameters = mh->size_of_parameters();
1022 callee_max_locals = mh->max_locals();
1023 is_top_frame = false;
1024 }
1025 }
1026 #endif // !PRODUCT
1027
1028 return bt;
1029 JRT_END
1030
1031 class DeoptimizeMarkedClosure : public HandshakeClosure {
1032 public:
1033 DeoptimizeMarkedClosure() : HandshakeClosure("Deoptimize") {}
1034 void do_thread(Thread* thread) {
1035 JavaThread* jt = JavaThread::cast(thread);
1036 jt->deoptimize_marked_methods();
1037 }
1038 };
1039
1040 void Deoptimization::deoptimize_all_marked() {
1041 ResourceMark rm;
1042
1043 // Make the dependent methods not entrant
1044 CodeCache::make_marked_nmethods_deoptimized();
1045
1046 DeoptimizeMarkedClosure deopt;
1047 if (SafepointSynchronize::is_at_safepoint()) {
1048 Threads::java_threads_do(&deopt);
1049 } else {
1050 Handshake::execute(&deopt);
1051 }
1052 }
1053
1054 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1055 = Deoptimization::Action_reinterpret;
1056
1057 #if INCLUDE_JVMCI
1058 template<typename CacheType>
1059 class BoxCacheBase : public CHeapObj<mtCompiler> {
1060 protected:
1061 static InstanceKlass* find_cache_klass(Thread* thread, Symbol* klass_name) {
1062 ResourceMark rm(thread);
1063 char* klass_name_str = klass_name->as_C_string();
1064 InstanceKlass* ik = SystemDictionary::find_instance_klass(thread, klass_name, Handle(), Handle());
1065 guarantee(ik != nullptr, "%s must be loaded", klass_name_str);
1066 if (!ik->is_in_error_state()) {
1067 guarantee(ik->is_initialized(), "%s must be initialized", klass_name_str);
1068 CacheType::compute_offsets(ik);
1069 }
1070 return ik;
1071 }
1072 };
1073
1074 template<typename PrimitiveType, typename CacheType, typename BoxType> class BoxCache : public BoxCacheBase<CacheType> {
1075 PrimitiveType _low;
1076 PrimitiveType _high;
1077 jobject _cache;
1078 protected:
1079 static BoxCache<PrimitiveType, CacheType, BoxType> *_singleton;
1080 BoxCache(Thread* thread) {
1081 InstanceKlass* ik = BoxCacheBase<CacheType>::find_cache_klass(thread, CacheType::symbol());
1082 if (ik->is_in_error_state()) {
1083 _low = 1;
1084 _high = 0;
1085 _cache = nullptr;
1086 } else {
1087 objArrayOop cache = CacheType::cache(ik);
1088 assert(cache->length() > 0, "Empty cache");
1089 _low = BoxType::value(cache->obj_at(0));
1090 _high = checked_cast<PrimitiveType>(_low + cache->length() - 1);
1091 _cache = JNIHandles::make_global(Handle(thread, cache));
1092 }
1093 }
1094 ~BoxCache() {
1095 JNIHandles::destroy_global(_cache);
1096 }
1097 public:
1098 static BoxCache<PrimitiveType, CacheType, BoxType>* singleton(Thread* thread) {
1099 if (_singleton == nullptr) {
1100 BoxCache<PrimitiveType, CacheType, BoxType>* s = new BoxCache<PrimitiveType, CacheType, BoxType>(thread);
1101 if (!Atomic::replace_if_null(&_singleton, s)) {
1102 delete s;
1103 }
1104 }
1105 return _singleton;
1106 }
1107 oop lookup(PrimitiveType value) {
1108 if (_low <= value && value <= _high) {
1109 int offset = checked_cast<int>(value - _low);
1110 return objArrayOop(JNIHandles::resolve_non_null(_cache))->obj_at(offset);
1111 }
1112 return nullptr;
1113 }
1114 oop lookup_raw(intptr_t raw_value, bool& cache_init_error) {
1115 if (_cache == nullptr) {
1116 cache_init_error = true;
1117 return nullptr;
1118 }
1119 // Have to cast to avoid little/big-endian problems.
1120 if (sizeof(PrimitiveType) > sizeof(jint)) {
1121 jlong value = (jlong)raw_value;
1122 return lookup(value);
1123 }
1124 PrimitiveType value = (PrimitiveType)*((jint*)&raw_value);
1125 return lookup(value);
1126 }
1127 };
1128
1129 typedef BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer> IntegerBoxCache;
1130 typedef BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long> LongBoxCache;
1131 typedef BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character> CharacterBoxCache;
1132 typedef BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short> ShortBoxCache;
1133 typedef BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte> ByteBoxCache;
1134
1135 template<> BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>* BoxCache<jint, java_lang_Integer_IntegerCache, java_lang_Integer>::_singleton = nullptr;
1136 template<> BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>* BoxCache<jlong, java_lang_Long_LongCache, java_lang_Long>::_singleton = nullptr;
1137 template<> BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>* BoxCache<jchar, java_lang_Character_CharacterCache, java_lang_Character>::_singleton = nullptr;
1138 template<> BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>* BoxCache<jshort, java_lang_Short_ShortCache, java_lang_Short>::_singleton = nullptr;
1139 template<> BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>* BoxCache<jbyte, java_lang_Byte_ByteCache, java_lang_Byte>::_singleton = nullptr;
1140
1141 class BooleanBoxCache : public BoxCacheBase<java_lang_Boolean> {
1142 jobject _true_cache;
1143 jobject _false_cache;
1144 protected:
1145 static BooleanBoxCache *_singleton;
1146 BooleanBoxCache(Thread *thread) {
1147 InstanceKlass* ik = find_cache_klass(thread, java_lang_Boolean::symbol());
1148 if (ik->is_in_error_state()) {
1149 _true_cache = nullptr;
1150 _false_cache = nullptr;
1151 } else {
1152 _true_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_TRUE(ik)));
1153 _false_cache = JNIHandles::make_global(Handle(thread, java_lang_Boolean::get_FALSE(ik)));
1154 }
1155 }
1156 ~BooleanBoxCache() {
1157 JNIHandles::destroy_global(_true_cache);
1158 JNIHandles::destroy_global(_false_cache);
1159 }
1160 public:
1161 static BooleanBoxCache* singleton(Thread* thread) {
1162 if (_singleton == nullptr) {
1163 BooleanBoxCache* s = new BooleanBoxCache(thread);
1164 if (!Atomic::replace_if_null(&_singleton, s)) {
1165 delete s;
1166 }
1167 }
1168 return _singleton;
1169 }
1170 oop lookup_raw(intptr_t raw_value, bool& cache_in_error) {
1171 if (_true_cache == nullptr) {
1172 cache_in_error = true;
1173 return nullptr;
1174 }
1175 // Have to cast to avoid little/big-endian problems.
1176 jboolean value = (jboolean)*((jint*)&raw_value);
1177 return lookup(value);
1178 }
1179 oop lookup(jboolean value) {
1180 if (value != 0) {
1181 return JNIHandles::resolve_non_null(_true_cache);
1182 }
1183 return JNIHandles::resolve_non_null(_false_cache);
1184 }
1185 };
1186
1187 BooleanBoxCache* BooleanBoxCache::_singleton = nullptr;
1188
1189 oop Deoptimization::get_cached_box(AutoBoxObjectValue* bv, frame* fr, RegisterMap* reg_map, bool& cache_init_error, TRAPS) {
1190 Klass* k = java_lang_Class::as_Klass(bv->klass()->as_ConstantOopReadValue()->value()());
1191 BasicType box_type = vmClasses::box_klass_type(k);
1192 if (box_type != T_OBJECT) {
1193 StackValue* value = StackValue::create_stack_value(fr, reg_map, bv->field_at(box_type == T_LONG ? 1 : 0));
1194 switch(box_type) {
1195 case T_INT: return IntegerBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1196 case T_CHAR: return CharacterBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1197 case T_SHORT: return ShortBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1198 case T_BYTE: return ByteBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1199 case T_BOOLEAN: return BooleanBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1200 case T_LONG: return LongBoxCache::singleton(THREAD)->lookup_raw(value->get_intptr(), cache_init_error);
1201 default:;
1202 }
1203 }
1204 return nullptr;
1205 }
1206 #endif // INCLUDE_JVMCI
1207
1208 #if COMPILER2_OR_JVMCI
1209 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, TRAPS) {
1210 Handle pending_exception(THREAD, thread->pending_exception());
1211 const char* exception_file = thread->exception_file();
1212 int exception_line = thread->exception_line();
1213 thread->clear_pending_exception();
1214
1215 bool failures = false;
1216
1217 for (int i = 0; i < objects->length(); i++) {
1218 assert(objects->at(i)->is_object(), "invalid debug information");
1219 ObjectValue* sv = (ObjectValue*) objects->at(i);
1220
1221 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1222 oop obj = nullptr;
1223
1224 bool cache_init_error = false;
1225 if (k->is_instance_klass()) {
1226 #if INCLUDE_JVMCI
1227 nmethod* nm = fr->cb()->as_nmethod_or_null();
1228 if (nm->is_compiled_by_jvmci() && sv->is_auto_box()) {
1229 AutoBoxObjectValue* abv = (AutoBoxObjectValue*) sv;
1230 obj = get_cached_box(abv, fr, reg_map, cache_init_error, THREAD);
1231 if (obj != nullptr) {
1232 // Set the flag to indicate the box came from a cache, so that we can skip the field reassignment for it.
1233 abv->set_cached(true);
1234 } else if (cache_init_error) {
1235 // Results in an OOME which is valid (as opposed to a class initialization error)
1236 // and is fine for the rare case a cache initialization failing.
1237 failures = true;
1238 }
1239 }
1240 #endif // INCLUDE_JVMCI
1241
1242 InstanceKlass* ik = InstanceKlass::cast(k);
1243 if (obj == nullptr && !cache_init_error) {
1244 InternalOOMEMark iom(THREAD);
1245 if (EnableVectorSupport && VectorSupport::is_vector(ik)) {
1246 obj = VectorSupport::allocate_vector(ik, fr, reg_map, sv, THREAD);
1247 } else {
1248 obj = ik->allocate_instance(THREAD);
1249 }
1250 }
1251 } else if (k->is_typeArray_klass()) {
1252 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1253 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
1254 int len = sv->field_size() / type2size[ak->element_type()];
1255 InternalOOMEMark iom(THREAD);
1256 obj = ak->allocate(len, THREAD);
1257 } else if (k->is_objArray_klass()) {
1258 ObjArrayKlass* ak = ObjArrayKlass::cast(k);
1259 InternalOOMEMark iom(THREAD);
1260 obj = ak->allocate(sv->field_size(), THREAD);
1261 }
1262
1263 if (obj == nullptr) {
1264 failures = true;
1265 }
1266
1267 assert(sv->value().is_null(), "redundant reallocation");
1268 assert(obj != nullptr || HAS_PENDING_EXCEPTION || cache_init_error, "allocation should succeed or we should get an exception");
1269 CLEAR_PENDING_EXCEPTION;
1270 sv->set_value(obj);
1271 }
1272
1273 if (failures) {
1274 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
1275 } else if (pending_exception.not_null()) {
1276 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
1277 }
1278
1279 return failures;
1280 }
1281
1282 #if INCLUDE_JVMCI
1283 /**
1284 * For primitive types whose kind gets "erased" at runtime (shorts become stack ints),
1285 * we need to somehow be able to recover the actual kind to be able to write the correct
1286 * amount of bytes.
1287 * For that purpose, this method assumes that, for an entry spanning n bytes at index i,
1288 * the entries at index n + 1 to n + i are 'markers'.
1289 * For example, if we were writing a short at index 4 of a byte array of size 8, the
1290 * expected form of the array would be:
1291 *
1292 * {b0, b1, b2, b3, INT, marker, b6, b7}
1293 *
1294 * Thus, in order to get back the size of the entry, we simply need to count the number
1295 * of marked entries
1296 *
1297 * @param virtualArray the virtualized byte array
1298 * @param i index of the virtual entry we are recovering
1299 * @return The number of bytes the entry spans
1300 */
1301 static int count_number_of_bytes_for_entry(ObjectValue *virtualArray, int i) {
1302 int index = i;
1303 while (++index < virtualArray->field_size() &&
1304 virtualArray->field_at(index)->is_marker()) {}
1305 return index - i;
1306 }
1307
1308 /**
1309 * If there was a guarantee for byte array to always start aligned to a long, we could
1310 * do a simple check on the parity of the index. Unfortunately, that is not always the
1311 * case. Thus, we check alignment of the actual address we are writing to.
1312 * In the unlikely case index 0 is 5-aligned for example, it would then be possible to
1313 * write a long to index 3.
1314 */
1315 static jbyte* check_alignment_get_addr(typeArrayOop obj, int index, int expected_alignment) {
1316 jbyte* res = obj->byte_at_addr(index);
1317 assert((((intptr_t) res) % expected_alignment) == 0, "Non-aligned write");
1318 return res;
1319 }
1320
1321 static void byte_array_put(typeArrayOop obj, StackValue* value, int index, int byte_count) {
1322 switch (byte_count) {
1323 case 1:
1324 obj->byte_at_put(index, (jbyte) value->get_jint());
1325 break;
1326 case 2:
1327 *((jshort *) check_alignment_get_addr(obj, index, 2)) = (jshort) value->get_jint();
1328 break;
1329 case 4:
1330 *((jint *) check_alignment_get_addr(obj, index, 4)) = value->get_jint();
1331 break;
1332 case 8:
1333 *((jlong *) check_alignment_get_addr(obj, index, 8)) = (jlong) value->get_intptr();
1334 break;
1335 default:
1336 ShouldNotReachHere();
1337 }
1338 }
1339 #endif // INCLUDE_JVMCI
1340
1341
1342 // restore elements of an eliminated type array
1343 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
1344 int index = 0;
1345
1346 for (int i = 0; i < sv->field_size(); i++) {
1347 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1348 switch(type) {
1349 case T_LONG: case T_DOUBLE: {
1350 assert(value->type() == T_INT, "Agreement.");
1351 StackValue* low =
1352 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1353 #ifdef _LP64
1354 jlong res = (jlong)low->get_intptr();
1355 #else
1356 jlong res = jlong_from(value->get_jint(), low->get_jint());
1357 #endif
1358 obj->long_at_put(index, res);
1359 break;
1360 }
1361
1362 case T_INT: case T_FLOAT: { // 4 bytes.
1363 assert(value->type() == T_INT, "Agreement.");
1364 bool big_value = false;
1365 if (i + 1 < sv->field_size() && type == T_INT) {
1366 if (sv->field_at(i)->is_location()) {
1367 Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
1368 if (type == Location::dbl || type == Location::lng) {
1369 big_value = true;
1370 }
1371 } else if (sv->field_at(i)->is_constant_int()) {
1372 ScopeValue* next_scope_field = sv->field_at(i + 1);
1373 if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1374 big_value = true;
1375 }
1376 }
1377 }
1378
1379 if (big_value) {
1380 StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
1381 #ifdef _LP64
1382 jlong res = (jlong)low->get_intptr();
1383 #else
1384 jlong res = jlong_from(value->get_jint(), low->get_jint());
1385 #endif
1386 obj->int_at_put(index, *(jint*)&res);
1387 obj->int_at_put(++index, *((jint*)&res + 1));
1388 } else {
1389 obj->int_at_put(index, value->get_jint());
1390 }
1391 break;
1392 }
1393
1394 case T_SHORT:
1395 assert(value->type() == T_INT, "Agreement.");
1396 obj->short_at_put(index, (jshort)value->get_jint());
1397 break;
1398
1399 case T_CHAR:
1400 assert(value->type() == T_INT, "Agreement.");
1401 obj->char_at_put(index, (jchar)value->get_jint());
1402 break;
1403
1404 case T_BYTE: {
1405 assert(value->type() == T_INT, "Agreement.");
1406 #if INCLUDE_JVMCI
1407 // The value we get is erased as a regular int. We will need to find its actual byte count 'by hand'.
1408 int byte_count = count_number_of_bytes_for_entry(sv, i);
1409 byte_array_put(obj, value, index, byte_count);
1410 // According to byte_count contract, the values from i + 1 to i + byte_count are illegal values. Skip.
1411 i += byte_count - 1; // Balance the loop counter.
1412 index += byte_count;
1413 // index has been updated so continue at top of loop
1414 continue;
1415 #else
1416 obj->byte_at_put(index, (jbyte)value->get_jint());
1417 break;
1418 #endif // INCLUDE_JVMCI
1419 }
1420
1421 case T_BOOLEAN: {
1422 assert(value->type() == T_INT, "Agreement.");
1423 obj->bool_at_put(index, (jboolean)value->get_jint());
1424 break;
1425 }
1426
1427 default:
1428 ShouldNotReachHere();
1429 }
1430 index++;
1431 }
1432 }
1433
1434 // restore fields of an eliminated object array
1435 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
1436 for (int i = 0; i < sv->field_size(); i++) {
1437 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
1438 assert(value->type() == T_OBJECT, "object element expected");
1439 obj->obj_at_put(i, value->get_obj()());
1440 }
1441 }
1442
1443 class ReassignedField {
1444 public:
1445 int _offset;
1446 BasicType _type;
1447 public:
1448 ReassignedField() {
1449 _offset = 0;
1450 _type = T_ILLEGAL;
1451 }
1452 };
1453
1454 static int compare(ReassignedField* left, ReassignedField* right) {
1455 return left->_offset - right->_offset;
1456 }
1457
1458 // Restore fields of an eliminated instance object using the same field order
1459 // returned by HotSpotResolvedObjectTypeImpl.getInstanceFields(true)
1460 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool skip_internal) {
1461 GrowableArray<ReassignedField>* fields = new GrowableArray<ReassignedField>();
1462 InstanceKlass* ik = klass;
1463 while (ik != nullptr) {
1464 for (AllFieldStream fs(ik); !fs.done(); fs.next()) {
1465 if (!fs.access_flags().is_static() && (!skip_internal || !fs.field_flags().is_injected())) {
1466 ReassignedField field;
1467 field._offset = fs.offset();
1468 field._type = Signature::basic_type(fs.signature());
1469 fields->append(field);
1470 }
1471 }
1472 ik = ik->superklass();
1473 }
1474 fields->sort(compare);
1475 for (int i = 0; i < fields->length(); i++) {
1476 ScopeValue* scope_field = sv->field_at(svIndex);
1477 StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
1478 int offset = fields->at(i)._offset;
1479 BasicType type = fields->at(i)._type;
1480 switch (type) {
1481 case T_OBJECT: case T_ARRAY:
1482 assert(value->type() == T_OBJECT, "Agreement.");
1483 obj->obj_field_put(offset, value->get_obj()());
1484 break;
1485
1486 case T_INT: case T_FLOAT: { // 4 bytes.
1487 assert(value->type() == T_INT, "Agreement.");
1488 bool big_value = false;
1489 if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
1490 if (scope_field->is_location()) {
1491 Location::Type type = ((LocationValue*) scope_field)->location().type();
1492 if (type == Location::dbl || type == Location::lng) {
1493 big_value = true;
1494 }
1495 }
1496 if (scope_field->is_constant_int()) {
1497 ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
1498 if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
1499 big_value = true;
1500 }
1501 }
1502 }
1503
1504 if (big_value) {
1505 i++;
1506 assert(i < fields->length(), "second T_INT field needed");
1507 assert(fields->at(i)._type == T_INT, "T_INT field needed");
1508 } else {
1509 obj->int_field_put(offset, value->get_jint());
1510 break;
1511 }
1512 }
1513 /* no break */
1514
1515 case T_LONG: case T_DOUBLE: {
1516 assert(value->type() == T_INT, "Agreement.");
1517 StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
1518 #ifdef _LP64
1519 jlong res = (jlong)low->get_intptr();
1520 #else
1521 jlong res = jlong_from(value->get_jint(), low->get_jint());
1522 #endif
1523 obj->long_field_put(offset, res);
1524 break;
1525 }
1526
1527 case T_SHORT:
1528 assert(value->type() == T_INT, "Agreement.");
1529 obj->short_field_put(offset, (jshort)value->get_jint());
1530 break;
1531
1532 case T_CHAR:
1533 assert(value->type() == T_INT, "Agreement.");
1534 obj->char_field_put(offset, (jchar)value->get_jint());
1535 break;
1536
1537 case T_BYTE:
1538 assert(value->type() == T_INT, "Agreement.");
1539 obj->byte_field_put(offset, (jbyte)value->get_jint());
1540 break;
1541
1542 case T_BOOLEAN:
1543 assert(value->type() == T_INT, "Agreement.");
1544 obj->bool_field_put(offset, (jboolean)value->get_jint());
1545 break;
1546
1547 default:
1548 ShouldNotReachHere();
1549 }
1550 svIndex++;
1551 }
1552 return svIndex;
1553 }
1554
1555 // restore fields of all eliminated objects and arrays
1556 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal) {
1557 for (int i = 0; i < objects->length(); i++) {
1558 assert(objects->at(i)->is_object(), "invalid debug information");
1559 ObjectValue* sv = (ObjectValue*) objects->at(i);
1560 Klass* k = java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()());
1561 Handle obj = sv->value();
1562 assert(obj.not_null() || realloc_failures, "reallocation was missed");
1563 #ifndef PRODUCT
1564 if (PrintDeoptimizationDetails) {
1565 tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1566 }
1567 #endif // !PRODUCT
1568
1569 if (obj.is_null()) {
1570 continue;
1571 }
1572
1573 #if INCLUDE_JVMCI
1574 // Don't reassign fields of boxes that came from a cache. Caches may be in CDS.
1575 if (sv->is_auto_box() && ((AutoBoxObjectValue*) sv)->is_cached()) {
1576 continue;
1577 }
1578 #endif // INCLUDE_JVMCI
1579 if (EnableVectorSupport && VectorSupport::is_vector(k)) {
1580 assert(sv->field_size() == 1, "%s not a vector", k->name()->as_C_string());
1581 ScopeValue* payload = sv->field_at(0);
1582 if (payload->is_location() &&
1583 payload->as_LocationValue()->location().type() == Location::vector) {
1584 #ifndef PRODUCT
1585 if (PrintDeoptimizationDetails) {
1586 tty->print_cr("skip field reassignment for this vector - it should be assigned already");
1587 if (Verbose) {
1588 Handle obj = sv->value();
1589 k->oop_print_on(obj(), tty);
1590 }
1591 }
1592 #endif // !PRODUCT
1593 continue; // Such vector's value was already restored in VectorSupport::allocate_vector().
1594 }
1595 // Else fall-through to do assignment for scalar-replaced boxed vector representation
1596 // which could be restored after vector object allocation.
1597 }
1598 if (k->is_instance_klass()) {
1599 InstanceKlass* ik = InstanceKlass::cast(k);
1600 reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), skip_internal);
1601 } else if (k->is_typeArray_klass()) {
1602 TypeArrayKlass* ak = TypeArrayKlass::cast(k);
1603 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1604 } else if (k->is_objArray_klass()) {
1605 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1606 }
1607 }
1608 // These objects may escape when we return to Interpreter after deoptimization.
1609 // We need barrier so that stores that initialize these objects can't be reordered
1610 // with subsequent stores that make these objects accessible by other threads.
1611 OrderAccess::storestore();
1612 }
1613
1614
1615 // relock objects for which synchronization was eliminated
1616 bool Deoptimization::relock_objects(JavaThread* thread, GrowableArray<MonitorInfo*>* monitors,
1617 JavaThread* deoptee_thread, frame& fr, int exec_mode, bool realloc_failures) {
1618 bool relocked_objects = false;
1619 for (int i = 0; i < monitors->length(); i++) {
1620 MonitorInfo* mon_info = monitors->at(i);
1621 if (mon_info->eliminated()) {
1622 assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1623 relocked_objects = true;
1624 if (!mon_info->owner_is_scalar_replaced()) {
1625 Handle obj(thread, mon_info->owner());
1626 markWord mark = obj->mark();
1627 if (exec_mode == Unpack_none) {
1628 if (LockingMode == LM_LEGACY && mark.has_locker() && fr.sp() > (intptr_t*)mark.locker()) {
1629 // With exec_mode == Unpack_none obj may be thread local and locked in
1630 // a callee frame. Make the lock in the callee a recursive lock and restore the displaced header.
1631 markWord dmw = mark.displaced_mark_helper();
1632 mark.locker()->set_displaced_header(markWord::encode((BasicLock*) nullptr));
1633 obj->set_mark(dmw);
1634 }
1635 if (mark.has_monitor()) {
1636 // defer relocking if the deoptee thread is currently waiting for obj
1637 ObjectMonitor* waiting_monitor = deoptee_thread->current_waiting_monitor();
1638 if (waiting_monitor != nullptr && waiting_monitor->object() == obj()) {
1639 assert(fr.is_deoptimized_frame(), "frame must be scheduled for deoptimization");
1640 if (LockingMode == LM_LEGACY) {
1641 mon_info->lock()->set_displaced_header(markWord::unused_mark());
1642 } else if (UseObjectMonitorTable) {
1643 mon_info->lock()->clear_object_monitor_cache();
1644 }
1645 #ifdef ASSERT
1646 else {
1647 assert(LockingMode == LM_MONITOR || !UseObjectMonitorTable, "must be");
1648 mon_info->lock()->set_bad_metadata_deopt();
1649 }
1650 #endif
1651 JvmtiDeferredUpdates::inc_relock_count_after_wait(deoptee_thread);
1652 continue;
1653 }
1654 }
1655 }
1656 BasicLock* lock = mon_info->lock();
1657 if (LockingMode == LM_LIGHTWEIGHT) {
1658 // We have lost information about the correct state of the lock stack.
1659 // Entering may create an invalid lock stack. Inflate the lock if it
1660 // was fast_locked to restore the valid lock stack.
1661 ObjectSynchronizer::enter_for(obj, lock, deoptee_thread);
1662 if (deoptee_thread->lock_stack().contains(obj())) {
1663 LightweightSynchronizer::inflate_fast_locked_object(obj(), ObjectSynchronizer::InflateCause::inflate_cause_vm_internal,
1664 deoptee_thread, thread);
1665 }
1666 assert(mon_info->owner()->is_locked(), "object must be locked now");
1667 assert(obj->mark().has_monitor(), "must be");
1668 assert(!deoptee_thread->lock_stack().contains(obj()), "must be");
1669 assert(ObjectSynchronizer::read_monitor(thread, obj(), obj->mark())->owner() == deoptee_thread, "must be");
1670 } else {
1671 ObjectSynchronizer::enter_for(obj, lock, deoptee_thread);
1672 assert(mon_info->owner()->is_locked(), "object must be locked now");
1673 }
1674 }
1675 }
1676 }
1677 return relocked_objects;
1678 }
1679 #endif // COMPILER2_OR_JVMCI
1680
1681 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1682 Events::log_deopt_message(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1683
1684 // Register map for next frame (used for stack crawl). We capture
1685 // the state of the deopt'ing frame's caller. Thus if we need to
1686 // stuff a C2I adapter we can properly fill in the callee-save
1687 // register locations.
1688 frame caller = fr.sender(reg_map);
1689 int frame_size = pointer_delta_as_int(caller.sp(), fr.sp());
1690
1691 frame sender = caller;
1692
1693 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1694 // the vframeArray containing the unpacking information is allocated in the C heap.
1695 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1696 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1697
1698 // Compare the vframeArray to the collected vframes
1699 assert(array->structural_compare(thread, chunk), "just checking");
1700
1701 if (TraceDeoptimization) {
1702 ResourceMark rm;
1703 stringStream st;
1704 st.print_cr("DEOPT PACKING thread=" INTPTR_FORMAT " vframeArray=" INTPTR_FORMAT, p2i(thread), p2i(array));
1705 st.print(" ");
1706 fr.print_on(&st);
1707 st.print_cr(" Virtual frames (innermost/newest first):");
1708 for (int index = 0; index < chunk->length(); index++) {
1709 compiledVFrame* vf = chunk->at(index);
1710 int bci = vf->raw_bci();
1711 const char* code_name;
1712 if (bci == SynchronizationEntryBCI) {
1713 code_name = "sync entry";
1714 } else {
1715 Bytecodes::Code code = vf->method()->code_at(bci);
1716 code_name = Bytecodes::name(code);
1717 }
1718
1719 st.print(" VFrame %d (" INTPTR_FORMAT ")", index, p2i(vf));
1720 st.print(" - %s", vf->method()->name_and_sig_as_C_string());
1721 st.print(" - %s", code_name);
1722 st.print_cr(" @ bci=%d ", bci);
1723 }
1724 tty->print_raw(st.freeze());
1725 tty->cr();
1726 }
1727
1728 return array;
1729 }
1730
1731 #if COMPILER2_OR_JVMCI
1732 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1733 // Reallocation of some scalar replaced objects failed. Record
1734 // that we need to pop all the interpreter frames for the
1735 // deoptimized compiled frame.
1736 assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1737 thread->set_frames_to_pop_failed_realloc(array->frames());
1738 // Unlock all monitors here otherwise the interpreter will see a
1739 // mix of locked and unlocked monitors (because of failed
1740 // reallocations of synchronized objects) and be confused.
1741 for (int i = 0; i < array->frames(); i++) {
1742 MonitorChunk* monitors = array->element(i)->monitors();
1743 if (monitors != nullptr) {
1744 // Unlock in reverse order starting from most nested monitor.
1745 for (int j = (monitors->number_of_monitors() - 1); j >= 0; j--) {
1746 BasicObjectLock* src = monitors->at(j);
1747 if (src->obj() != nullptr) {
1748 ObjectSynchronizer::exit(src->obj(), src->lock(), thread);
1749 }
1750 }
1751 array->element(i)->free_monitors();
1752 #ifdef ASSERT
1753 array->element(i)->set_removed_monitors();
1754 #endif
1755 }
1756 }
1757 }
1758 #endif
1759
1760 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1761 assert(fr.can_be_deoptimized(), "checking frame type");
1762
1763 gather_statistics(reason, Action_none, Bytecodes::_illegal);
1764
1765 if (LogCompilation && xtty != nullptr) {
1766 nmethod* nm = fr.cb()->as_nmethod_or_null();
1767 assert(nm != nullptr, "only compiled methods can deopt");
1768
1769 ttyLocker ttyl;
1770 xtty->begin_head("deoptimized thread='" UINTX_FORMAT "' reason='%s' pc='" INTPTR_FORMAT "'",(uintx)thread->osthread()->thread_id(), trap_reason_name(reason), p2i(fr.pc()));
1771 nm->log_identity(xtty);
1772 xtty->end_head();
1773 for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1774 xtty->begin_elem("jvms bci='%d'", sd->bci());
1775 xtty->method(sd->method());
1776 xtty->end_elem();
1777 if (sd->is_top()) break;
1778 }
1779 xtty->tail("deoptimized");
1780 }
1781
1782 Continuation::notify_deopt(thread, fr.sp());
1783
1784 // Patch the compiled method so that when execution returns to it we will
1785 // deopt the execution state and return to the interpreter.
1786 fr.deoptimize(thread);
1787 }
1788
1789 void Deoptimization::deoptimize(JavaThread* thread, frame fr, DeoptReason reason) {
1790 // Deoptimize only if the frame comes from compile code.
1791 // Do not deoptimize the frame which is already patched
1792 // during the execution of the loops below.
1793 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1794 return;
1795 }
1796 ResourceMark rm;
1797 deoptimize_single_frame(thread, fr, reason);
1798 }
1799
1800 #if INCLUDE_JVMCI
1801 address Deoptimization::deoptimize_for_missing_exception_handler(nmethod* nm) {
1802 // there is no exception handler for this pc => deoptimize
1803 nm->make_not_entrant();
1804
1805 // Use Deoptimization::deoptimize for all of its side-effects:
1806 // gathering traps statistics, logging...
1807 // it also patches the return pc but we do not care about that
1808 // since we return a continuation to the deopt_blob below.
1809 JavaThread* thread = JavaThread::current();
1810 RegisterMap reg_map(thread,
1811 RegisterMap::UpdateMap::skip,
1812 RegisterMap::ProcessFrames::include,
1813 RegisterMap::WalkContinuation::skip);
1814 frame runtime_frame = thread->last_frame();
1815 frame caller_frame = runtime_frame.sender(®_map);
1816 assert(caller_frame.cb()->as_nmethod_or_null() == nm, "expect top frame compiled method");
1817 vframe* vf = vframe::new_vframe(&caller_frame, ®_map, thread);
1818 compiledVFrame* cvf = compiledVFrame::cast(vf);
1819 ScopeDesc* imm_scope = cvf->scope();
1820 MethodData* imm_mdo = get_method_data(thread, methodHandle(thread, imm_scope->method()), true);
1821 if (imm_mdo != nullptr) {
1822 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
1823 MutexLocker ml(imm_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
1824
1825 ProfileData* pdata = imm_mdo->allocate_bci_to_data(imm_scope->bci(), nullptr);
1826 if (pdata != nullptr && pdata->is_BitData()) {
1827 BitData* bit_data = (BitData*) pdata;
1828 bit_data->set_exception_seen();
1829 }
1830 }
1831
1832 Deoptimization::deoptimize(thread, caller_frame, Deoptimization::Reason_not_compiled_exception_handler);
1833
1834 MethodData* trap_mdo = get_method_data(thread, methodHandle(thread, nm->method()), true);
1835 if (trap_mdo != nullptr) {
1836 trap_mdo->inc_trap_count(Deoptimization::Reason_not_compiled_exception_handler);
1837 }
1838
1839 return SharedRuntime::deopt_blob()->unpack_with_exception_in_tls();
1840 }
1841 #endif
1842
1843 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1844 assert(thread == Thread::current() ||
1845 thread->is_handshake_safe_for(Thread::current()) ||
1846 SafepointSynchronize::is_at_safepoint(),
1847 "can only deoptimize other thread at a safepoint/handshake");
1848 // Compute frame and register map based on thread and sp.
1849 RegisterMap reg_map(thread,
1850 RegisterMap::UpdateMap::skip,
1851 RegisterMap::ProcessFrames::include,
1852 RegisterMap::WalkContinuation::skip);
1853 frame fr = thread->last_frame();
1854 while (fr.id() != id) {
1855 fr = fr.sender(®_map);
1856 }
1857 deoptimize(thread, fr, reason);
1858 }
1859
1860
1861 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1862 Thread* current = Thread::current();
1863 if (thread == current || thread->is_handshake_safe_for(current)) {
1864 Deoptimization::deoptimize_frame_internal(thread, id, reason);
1865 } else {
1866 VM_DeoptimizeFrame deopt(thread, id, reason);
1867 VMThread::execute(&deopt);
1868 }
1869 }
1870
1871 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1872 deoptimize_frame(thread, id, Reason_constraint);
1873 }
1874
1875 // JVMTI PopFrame support
1876 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1877 {
1878 assert(thread == JavaThread::current(), "pre-condition");
1879 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1880 }
1881 JRT_END
1882
1883 MethodData*
1884 Deoptimization::get_method_data(JavaThread* thread, const methodHandle& m,
1885 bool create_if_missing) {
1886 JavaThread* THREAD = thread; // For exception macros.
1887 MethodData* mdo = m()->method_data();
1888 if (mdo == nullptr && create_if_missing && !HAS_PENDING_EXCEPTION) {
1889 // Build an MDO. Ignore errors like OutOfMemory;
1890 // that simply means we won't have an MDO to update.
1891 Method::build_profiling_method_data(m, THREAD);
1892 if (HAS_PENDING_EXCEPTION) {
1893 // Only metaspace OOM is expected. No Java code executed.
1894 assert((PENDING_EXCEPTION->is_a(vmClasses::OutOfMemoryError_klass())), "we expect only an OOM error here");
1895 CLEAR_PENDING_EXCEPTION;
1896 }
1897 mdo = m()->method_data();
1898 }
1899 return mdo;
1900 }
1901
1902 #if COMPILER2_OR_JVMCI
1903 void Deoptimization::load_class_by_index(const constantPoolHandle& constant_pool, int index, TRAPS) {
1904 // In case of an unresolved klass entry, load the class.
1905 // This path is exercised from case _ldc in Parse::do_one_bytecode,
1906 // and probably nowhere else.
1907 // Even that case would benefit from simply re-interpreting the
1908 // bytecode, without paying special attention to the class index.
1909 // So this whole "class index" feature should probably be removed.
1910
1911 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1912 Klass* tk = constant_pool->klass_at(index, THREAD);
1913 if (HAS_PENDING_EXCEPTION) {
1914 // Exception happened during classloading. We ignore the exception here, since it
1915 // is going to be rethrown since the current activation is going to be deoptimized and
1916 // the interpreter will re-execute the bytecode.
1917 // Do not clear probable Async Exceptions.
1918 CLEAR_PENDING_NONASYNC_EXCEPTION;
1919 // Class loading called java code which may have caused a stack
1920 // overflow. If the exception was thrown right before the return
1921 // to the runtime the stack is no longer guarded. Reguard the
1922 // stack otherwise if we return to the uncommon trap blob and the
1923 // stack bang causes a stack overflow we crash.
1924 JavaThread* jt = THREAD;
1925 bool guard_pages_enabled = jt->stack_overflow_state()->reguard_stack_if_needed();
1926 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1927 }
1928 return;
1929 }
1930
1931 assert(!constant_pool->tag_at(index).is_symbol(),
1932 "no symbolic names here, please");
1933 }
1934
1935 #if INCLUDE_JFR
1936
1937 class DeoptReasonSerializer : public JfrSerializer {
1938 public:
1939 void serialize(JfrCheckpointWriter& writer) {
1940 writer.write_count((u4)(Deoptimization::Reason_LIMIT + 1)); // + Reason::many (-1)
1941 for (int i = -1; i < Deoptimization::Reason_LIMIT; ++i) {
1942 writer.write_key((u8)i);
1943 writer.write(Deoptimization::trap_reason_name(i));
1944 }
1945 }
1946 };
1947
1948 class DeoptActionSerializer : public JfrSerializer {
1949 public:
1950 void serialize(JfrCheckpointWriter& writer) {
1951 static const u4 nof_actions = Deoptimization::Action_LIMIT;
1952 writer.write_count(nof_actions);
1953 for (u4 i = 0; i < Deoptimization::Action_LIMIT; ++i) {
1954 writer.write_key(i);
1955 writer.write(Deoptimization::trap_action_name((int)i));
1956 }
1957 }
1958 };
1959
1960 static void register_serializers() {
1961 static int critical_section = 0;
1962 if (1 == critical_section || Atomic::cmpxchg(&critical_section, 0, 1) == 1) {
1963 return;
1964 }
1965 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONREASON, true, new DeoptReasonSerializer());
1966 JfrSerializer::register_serializer(TYPE_DEOPTIMIZATIONACTION, true, new DeoptActionSerializer());
1967 }
1968
1969 static void post_deoptimization_event(nmethod* nm,
1970 const Method* method,
1971 int trap_bci,
1972 int instruction,
1973 Deoptimization::DeoptReason reason,
1974 Deoptimization::DeoptAction action) {
1975 assert(nm != nullptr, "invariant");
1976 assert(method != nullptr, "invariant");
1977 if (EventDeoptimization::is_enabled()) {
1978 static bool serializers_registered = false;
1979 if (!serializers_registered) {
1980 register_serializers();
1981 serializers_registered = true;
1982 }
1983 EventDeoptimization event;
1984 event.set_compileId(nm->compile_id());
1985 event.set_compiler(nm->compiler_type());
1986 event.set_method(method);
1987 event.set_lineNumber(method->line_number_from_bci(trap_bci));
1988 event.set_bci(trap_bci);
1989 event.set_instruction(instruction);
1990 event.set_reason(reason);
1991 event.set_action(action);
1992 event.commit();
1993 }
1994 }
1995
1996 #endif // INCLUDE_JFR
1997
1998 static void log_deopt(nmethod* nm, Method* tm, intptr_t pc, frame& fr, int trap_bci,
1999 const char* reason_name, const char* reason_action) {
2000 LogTarget(Debug, deoptimization) lt;
2001 if (lt.is_enabled()) {
2002 LogStream ls(lt);
2003 bool is_osr = nm->is_osr_method();
2004 ls.print("cid=%4d %s level=%d",
2005 nm->compile_id(), (is_osr ? "osr" : " "), nm->comp_level());
2006 ls.print(" %s", tm->name_and_sig_as_C_string());
2007 ls.print(" trap_bci=%d ", trap_bci);
2008 if (is_osr) {
2009 ls.print("osr_bci=%d ", nm->osr_entry_bci());
2010 }
2011 ls.print("%s ", reason_name);
2012 ls.print("%s ", reason_action);
2013 ls.print_cr("pc=" INTPTR_FORMAT " relative_pc=" INTPTR_FORMAT,
2014 pc, fr.pc() - nm->code_begin());
2015 }
2016 }
2017
2018 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* current, jint trap_request)) {
2019 HandleMark hm(current);
2020
2021 // uncommon_trap() is called at the beginning of the uncommon trap
2022 // handler. Note this fact before we start generating temporary frames
2023 // that can confuse an asynchronous stack walker. This counter is
2024 // decremented at the end of unpack_frames().
2025
2026 current->inc_in_deopt_handler();
2027
2028 #if INCLUDE_JVMCI
2029 // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
2030 RegisterMap reg_map(current,
2031 RegisterMap::UpdateMap::include,
2032 RegisterMap::ProcessFrames::include,
2033 RegisterMap::WalkContinuation::skip);
2034 #else
2035 RegisterMap reg_map(current,
2036 RegisterMap::UpdateMap::skip,
2037 RegisterMap::ProcessFrames::include,
2038 RegisterMap::WalkContinuation::skip);
2039 #endif
2040 frame stub_frame = current->last_frame();
2041 frame fr = stub_frame.sender(®_map);
2042
2043 // Log a message
2044 Events::log_deopt_message(current, "Uncommon trap: trap_request=" INT32_FORMAT_X_0 " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
2045 trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
2046
2047 {
2048 ResourceMark rm;
2049
2050 DeoptReason reason = trap_request_reason(trap_request);
2051 DeoptAction action = trap_request_action(trap_request);
2052 #if INCLUDE_JVMCI
2053 int debug_id = trap_request_debug_id(trap_request);
2054 #endif
2055 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
2056
2057 vframe* vf = vframe::new_vframe(&fr, ®_map, current);
2058 compiledVFrame* cvf = compiledVFrame::cast(vf);
2059
2060 nmethod* nm = cvf->code();
2061
2062 ScopeDesc* trap_scope = cvf->scope();
2063
2064 bool is_receiver_constraint_failure = COMPILER2_PRESENT(VerifyReceiverTypes &&) (reason == Deoptimization::Reason_receiver_constraint);
2065
2066 if (is_receiver_constraint_failure) {
2067 tty->print_cr(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"),
2068 trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
2069 JVMCI_ONLY(COMMA debug_id));
2070 }
2071
2072 methodHandle trap_method(current, trap_scope->method());
2073 int trap_bci = trap_scope->bci();
2074 #if INCLUDE_JVMCI
2075 jlong speculation = current->pending_failed_speculation();
2076 if (nm->is_compiled_by_jvmci()) {
2077 nm->update_speculation(current);
2078 } else {
2079 assert(speculation == 0, "There should not be a speculation for methods compiled by non-JVMCI compilers");
2080 }
2081
2082 if (trap_bci == SynchronizationEntryBCI) {
2083 trap_bci = 0;
2084 current->set_pending_monitorenter(true);
2085 }
2086
2087 if (reason == Deoptimization::Reason_transfer_to_interpreter) {
2088 current->set_pending_transfer_to_interpreter(true);
2089 }
2090 #endif
2091
2092 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
2093 // Record this event in the histogram.
2094 gather_statistics(reason, action, trap_bc);
2095
2096 // Ensure that we can record deopt. history:
2097 bool create_if_missing = ProfileTraps;
2098
2099 methodHandle profiled_method;
2100 #if INCLUDE_JVMCI
2101 if (nm->is_compiled_by_jvmci()) {
2102 profiled_method = methodHandle(current, nm->method());
2103 } else {
2104 profiled_method = trap_method;
2105 }
2106 #else
2107 profiled_method = trap_method;
2108 #endif
2109
2110 MethodData* trap_mdo =
2111 get_method_data(current, profiled_method, create_if_missing);
2112
2113 { // Log Deoptimization event for JFR, UL and event system
2114 Method* tm = trap_method();
2115 const char* reason_name = trap_reason_name(reason);
2116 const char* reason_action = trap_action_name(action);
2117 intptr_t pc = p2i(fr.pc());
2118
2119 JFR_ONLY(post_deoptimization_event(nm, tm, trap_bci, trap_bc, reason, action);)
2120 log_deopt(nm, tm, pc, fr, trap_bci, reason_name, reason_action);
2121 Events::log_deopt_message(current, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d %s",
2122 reason_name, reason_action, pc,
2123 tm->name_and_sig_as_C_string(), trap_bci, nm->compiler_name());
2124 }
2125
2126 // Print a bunch of diagnostics, if requested.
2127 if (TraceDeoptimization || LogCompilation || is_receiver_constraint_failure) {
2128 ResourceMark rm;
2129
2130 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2131 // We must do this already now, since we cannot acquire this lock while
2132 // holding the tty lock (lock ordering by rank).
2133 MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2134
2135 ttyLocker ttyl;
2136
2137 char buf[100];
2138 if (xtty != nullptr) {
2139 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT "' %s",
2140 os::current_thread_id(),
2141 format_trap_request(buf, sizeof(buf), trap_request));
2142 #if INCLUDE_JVMCI
2143 if (speculation != 0) {
2144 xtty->print(" speculation='" JLONG_FORMAT "'", speculation);
2145 }
2146 #endif
2147 nm->log_identity(xtty);
2148 }
2149 Symbol* class_name = nullptr;
2150 bool unresolved = false;
2151 if (unloaded_class_index >= 0) {
2152 constantPoolHandle constants (current, trap_method->constants());
2153 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
2154 class_name = constants->klass_name_at(unloaded_class_index);
2155 unresolved = true;
2156 if (xtty != nullptr)
2157 xtty->print(" unresolved='1'");
2158 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
2159 class_name = constants->symbol_at(unloaded_class_index);
2160 }
2161 if (xtty != nullptr)
2162 xtty->name(class_name);
2163 }
2164 if (xtty != nullptr && trap_mdo != nullptr && (int)reason < (int)MethodData::_trap_hist_limit) {
2165 // Dump the relevant MDO state.
2166 // This is the deopt count for the current reason, any previous
2167 // reasons or recompiles seen at this point.
2168 int dcnt = trap_mdo->trap_count(reason);
2169 if (dcnt != 0)
2170 xtty->print(" count='%d'", dcnt);
2171
2172 // We need to lock to read the ProfileData. But to keep the locks ordered, we need to
2173 // lock extra_data_lock before the tty lock.
2174 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
2175 int dos = (pdata == nullptr)? 0: pdata->trap_state();
2176 if (dos != 0) {
2177 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
2178 if (trap_state_is_recompiled(dos)) {
2179 int recnt2 = trap_mdo->overflow_recompile_count();
2180 if (recnt2 != 0)
2181 xtty->print(" recompiles2='%d'", recnt2);
2182 }
2183 }
2184 }
2185 if (xtty != nullptr) {
2186 xtty->stamp();
2187 xtty->end_head();
2188 }
2189 if (TraceDeoptimization) { // make noise on the tty
2190 stringStream st;
2191 st.print("UNCOMMON TRAP method=%s", trap_scope->method()->name_and_sig_as_C_string());
2192 st.print(" bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT JVMCI_ONLY(", debug_id=%d"),
2193 trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin() JVMCI_ONLY(COMMA debug_id));
2194 st.print(" compiler=%s compile_id=%d", nm->compiler_name(), nm->compile_id());
2195 #if INCLUDE_JVMCI
2196 if (nm->is_compiled_by_jvmci()) {
2197 const char* installed_code_name = nm->jvmci_name();
2198 if (installed_code_name != nullptr) {
2199 st.print(" (JVMCI: installed code name=%s) ", installed_code_name);
2200 }
2201 }
2202 #endif
2203 st.print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
2204 p2i(fr.pc()),
2205 os::current_thread_id(),
2206 trap_reason_name(reason),
2207 trap_action_name(action),
2208 unloaded_class_index
2209 #if INCLUDE_JVMCI
2210 , debug_id
2211 #endif
2212 );
2213 if (class_name != nullptr) {
2214 st.print(unresolved ? " unresolved class: " : " symbol: ");
2215 class_name->print_symbol_on(&st);
2216 }
2217 st.cr();
2218 tty->print_raw(st.freeze());
2219 }
2220 if (xtty != nullptr) {
2221 // Log the precise location of the trap.
2222 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
2223 xtty->begin_elem("jvms bci='%d'", sd->bci());
2224 xtty->method(sd->method());
2225 xtty->end_elem();
2226 if (sd->is_top()) break;
2227 }
2228 xtty->tail("uncommon_trap");
2229 }
2230 }
2231 // (End diagnostic printout.)
2232
2233 if (is_receiver_constraint_failure) {
2234 fatal("missing receiver type check");
2235 }
2236
2237 // Load class if necessary
2238 if (unloaded_class_index >= 0) {
2239 constantPoolHandle constants(current, trap_method->constants());
2240 load_class_by_index(constants, unloaded_class_index, THREAD);
2241 }
2242
2243 // Flush the nmethod if necessary and desirable.
2244 //
2245 // We need to avoid situations where we are re-flushing the nmethod
2246 // because of a hot deoptimization site. Repeated flushes at the same
2247 // point need to be detected by the compiler and avoided. If the compiler
2248 // cannot avoid them (or has a bug and "refuses" to avoid them), this
2249 // module must take measures to avoid an infinite cycle of recompilation
2250 // and deoptimization. There are several such measures:
2251 //
2252 // 1. If a recompilation is ordered a second time at some site X
2253 // and for the same reason R, the action is adjusted to 'reinterpret',
2254 // to give the interpreter time to exercise the method more thoroughly.
2255 // If this happens, the method's overflow_recompile_count is incremented.
2256 //
2257 // 2. If the compiler fails to reduce the deoptimization rate, then
2258 // the method's overflow_recompile_count will begin to exceed the set
2259 // limit PerBytecodeRecompilationCutoff. If this happens, the action
2260 // is adjusted to 'make_not_compilable', and the method is abandoned
2261 // to the interpreter. This is a performance hit for hot methods,
2262 // but is better than a disastrous infinite cycle of recompilations.
2263 // (Actually, only the method containing the site X is abandoned.)
2264 //
2265 // 3. In parallel with the previous measures, if the total number of
2266 // recompilations of a method exceeds the much larger set limit
2267 // PerMethodRecompilationCutoff, the method is abandoned.
2268 // This should only happen if the method is very large and has
2269 // many "lukewarm" deoptimizations. The code which enforces this
2270 // limit is elsewhere (class nmethod, class Method).
2271 //
2272 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
2273 // to recompile at each bytecode independently of the per-BCI cutoff.
2274 //
2275 // The decision to update code is up to the compiler, and is encoded
2276 // in the Action_xxx code. If the compiler requests Action_none
2277 // no trap state is changed, no compiled code is changed, and the
2278 // computation suffers along in the interpreter.
2279 //
2280 // The other action codes specify various tactics for decompilation
2281 // and recompilation. Action_maybe_recompile is the loosest, and
2282 // allows the compiled code to stay around until enough traps are seen,
2283 // and until the compiler gets around to recompiling the trapping method.
2284 //
2285 // The other actions cause immediate removal of the present code.
2286
2287 // Traps caused by injected profile shouldn't pollute trap counts.
2288 bool injected_profile_trap = trap_method->has_injected_profile() &&
2289 (reason == Reason_intrinsic || reason == Reason_unreached);
2290
2291 bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
2292 bool make_not_entrant = false;
2293 bool make_not_compilable = false;
2294 bool reprofile = false;
2295 switch (action) {
2296 case Action_none:
2297 // Keep the old code.
2298 update_trap_state = false;
2299 break;
2300 case Action_maybe_recompile:
2301 // Do not need to invalidate the present code, but we can
2302 // initiate another
2303 // Start compiler without (necessarily) invalidating the nmethod.
2304 // The system will tolerate the old code, but new code should be
2305 // generated when possible.
2306 break;
2307 case Action_reinterpret:
2308 // Go back into the interpreter for a while, and then consider
2309 // recompiling form scratch.
2310 make_not_entrant = true;
2311 // Reset invocation counter for outer most method.
2312 // This will allow the interpreter to exercise the bytecodes
2313 // for a while before recompiling.
2314 // By contrast, Action_make_not_entrant is immediate.
2315 //
2316 // Note that the compiler will track null_check, null_assert,
2317 // range_check, and class_check events and log them as if they
2318 // had been traps taken from compiled code. This will update
2319 // the MDO trap history so that the next compilation will
2320 // properly detect hot trap sites.
2321 reprofile = true;
2322 break;
2323 case Action_make_not_entrant:
2324 // Request immediate recompilation, and get rid of the old code.
2325 // Make them not entrant, so next time they are called they get
2326 // recompiled. Unloaded classes are loaded now so recompile before next
2327 // time they are called. Same for uninitialized. The interpreter will
2328 // link the missing class, if any.
2329 make_not_entrant = true;
2330 break;
2331 case Action_make_not_compilable:
2332 // Give up on compiling this method at all.
2333 make_not_entrant = true;
2334 make_not_compilable = true;
2335 break;
2336 default:
2337 ShouldNotReachHere();
2338 }
2339
2340 // Setting +ProfileTraps fixes the following, on all platforms:
2341 // 4852688: ProfileInterpreter is off by default for ia64. The result is
2342 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
2343 // recompile relies on a MethodData* to record heroic opt failures.
2344
2345 // Whether the interpreter is producing MDO data or not, we also need
2346 // to use the MDO to detect hot deoptimization points and control
2347 // aggressive optimization.
2348 bool inc_recompile_count = false;
2349
2350 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2351 ConditionalMutexLocker ml((trap_mdo != nullptr) ? trap_mdo->extra_data_lock() : nullptr,
2352 (trap_mdo != nullptr),
2353 Mutex::_no_safepoint_check_flag);
2354 ProfileData* pdata = nullptr;
2355 if (ProfileTraps && CompilerConfig::is_c2_or_jvmci_compiler_enabled() && update_trap_state && trap_mdo != nullptr) {
2356 assert(trap_mdo == get_method_data(current, profiled_method, false), "sanity");
2357 uint this_trap_count = 0;
2358 bool maybe_prior_trap = false;
2359 bool maybe_prior_recompile = false;
2360
2361 pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
2362 #if INCLUDE_JVMCI
2363 nm->is_compiled_by_jvmci() && nm->is_osr_method(),
2364 #endif
2365 nm->method(),
2366 //outputs:
2367 this_trap_count,
2368 maybe_prior_trap,
2369 maybe_prior_recompile);
2370 // Because the interpreter also counts null, div0, range, and class
2371 // checks, these traps from compiled code are double-counted.
2372 // This is harmless; it just means that the PerXTrapLimit values
2373 // are in effect a little smaller than they look.
2374
2375 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2376 if (per_bc_reason != Reason_none) {
2377 // Now take action based on the partially known per-BCI history.
2378 if (maybe_prior_trap
2379 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
2380 // If there are too many traps at this BCI, force a recompile.
2381 // This will allow the compiler to see the limit overflow, and
2382 // take corrective action, if possible. The compiler generally
2383 // does not use the exact PerBytecodeTrapLimit value, but instead
2384 // changes its tactics if it sees any traps at all. This provides
2385 // a little hysteresis, delaying a recompile until a trap happens
2386 // several times.
2387 //
2388 // Actually, since there is only one bit of counter per BCI,
2389 // the possible per-BCI counts are {0,1,(per-method count)}.
2390 // This produces accurate results if in fact there is only
2391 // one hot trap site, but begins to get fuzzy if there are
2392 // many sites. For example, if there are ten sites each
2393 // trapping two or more times, they each get the blame for
2394 // all of their traps.
2395 make_not_entrant = true;
2396 }
2397
2398 // Detect repeated recompilation at the same BCI, and enforce a limit.
2399 if (make_not_entrant && maybe_prior_recompile) {
2400 // More than one recompile at this point.
2401 inc_recompile_count = maybe_prior_trap;
2402 }
2403 } else {
2404 // For reasons which are not recorded per-bytecode, we simply
2405 // force recompiles unconditionally.
2406 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
2407 make_not_entrant = true;
2408 }
2409
2410 // Go back to the compiler if there are too many traps in this method.
2411 if (this_trap_count >= per_method_trap_limit(reason)) {
2412 // If there are too many traps in this method, force a recompile.
2413 // This will allow the compiler to see the limit overflow, and
2414 // take corrective action, if possible.
2415 // (This condition is an unlikely backstop only, because the
2416 // PerBytecodeTrapLimit is more likely to take effect first,
2417 // if it is applicable.)
2418 make_not_entrant = true;
2419 }
2420
2421 // Here's more hysteresis: If there has been a recompile at
2422 // this trap point already, run the method in the interpreter
2423 // for a while to exercise it more thoroughly.
2424 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
2425 reprofile = true;
2426 }
2427 }
2428
2429 // Take requested actions on the method:
2430
2431 // Recompile
2432 if (make_not_entrant) {
2433 if (!nm->make_not_entrant()) {
2434 return; // the call did not change nmethod's state
2435 }
2436
2437 if (pdata != nullptr) {
2438 // Record the recompilation event, if any.
2439 int tstate0 = pdata->trap_state();
2440 int tstate1 = trap_state_set_recompiled(tstate0, true);
2441 if (tstate1 != tstate0)
2442 pdata->set_trap_state(tstate1);
2443 }
2444
2445 // For code aging we count traps separately here, using make_not_entrant()
2446 // as a guard against simultaneous deopts in multiple threads.
2447 if (reason == Reason_tenured && trap_mdo != nullptr) {
2448 trap_mdo->inc_tenure_traps();
2449 }
2450 }
2451
2452 if (inc_recompile_count) {
2453 trap_mdo->inc_overflow_recompile_count();
2454 if ((uint)trap_mdo->overflow_recompile_count() >
2455 (uint)PerBytecodeRecompilationCutoff) {
2456 // Give up on the method containing the bad BCI.
2457 if (trap_method() == nm->method()) {
2458 make_not_compilable = true;
2459 } else {
2460 trap_method->set_not_compilable("overflow_recompile_count > PerBytecodeRecompilationCutoff", CompLevel_full_optimization);
2461 // But give grace to the enclosing nm->method().
2462 }
2463 }
2464 }
2465
2466 // Reprofile
2467 if (reprofile) {
2468 CompilationPolicy::reprofile(trap_scope, nm->is_osr_method());
2469 }
2470
2471 // Give up compiling
2472 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
2473 assert(make_not_entrant, "consistent");
2474 nm->method()->set_not_compilable("give up compiling", CompLevel_full_optimization);
2475 }
2476
2477 if (ProfileExceptionHandlers && trap_mdo != nullptr) {
2478 BitData* exception_handler_data = trap_mdo->exception_handler_bci_to_data_or_null(trap_bci);
2479 if (exception_handler_data != nullptr) {
2480 // uncommon trap at the start of an exception handler.
2481 // C2 generates these for un-entered exception handlers.
2482 // mark the handler as entered to avoid generating
2483 // another uncommon trap the next time the handler is compiled
2484 exception_handler_data->set_exception_handler_entered();
2485 }
2486 }
2487
2488 } // Free marked resources
2489
2490 }
2491 JRT_END
2492
2493 ProfileData*
2494 Deoptimization::query_update_method_data(MethodData* trap_mdo,
2495 int trap_bci,
2496 Deoptimization::DeoptReason reason,
2497 bool update_total_trap_count,
2498 #if INCLUDE_JVMCI
2499 bool is_osr,
2500 #endif
2501 Method* compiled_method,
2502 //outputs:
2503 uint& ret_this_trap_count,
2504 bool& ret_maybe_prior_trap,
2505 bool& ret_maybe_prior_recompile) {
2506 trap_mdo->check_extra_data_locked();
2507
2508 bool maybe_prior_trap = false;
2509 bool maybe_prior_recompile = false;
2510 uint this_trap_count = 0;
2511 if (update_total_trap_count) {
2512 uint idx = reason;
2513 #if INCLUDE_JVMCI
2514 if (is_osr) {
2515 // Upper half of history array used for traps in OSR compilations
2516 idx += Reason_TRAP_HISTORY_LENGTH;
2517 }
2518 #endif
2519 uint prior_trap_count = trap_mdo->trap_count(idx);
2520 this_trap_count = trap_mdo->inc_trap_count(idx);
2521
2522 // If the runtime cannot find a place to store trap history,
2523 // it is estimated based on the general condition of the method.
2524 // If the method has ever been recompiled, or has ever incurred
2525 // a trap with the present reason , then this BCI is assumed
2526 // (pessimistically) to be the culprit.
2527 maybe_prior_trap = (prior_trap_count != 0);
2528 maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
2529 }
2530 ProfileData* pdata = nullptr;
2531
2532
2533 // For reasons which are recorded per bytecode, we check per-BCI data.
2534 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
2535 assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
2536 if (per_bc_reason != Reason_none) {
2537 // Find the profile data for this BCI. If there isn't one,
2538 // try to allocate one from the MDO's set of spares.
2539 // This will let us detect a repeated trap at this point.
2540 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : nullptr);
2541
2542 if (pdata != nullptr) {
2543 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
2544 if (LogCompilation && xtty != nullptr) {
2545 ttyLocker ttyl;
2546 // no more room for speculative traps in this MDO
2547 xtty->elem("speculative_traps_oom");
2548 }
2549 }
2550 // Query the trap state of this profile datum.
2551 int tstate0 = pdata->trap_state();
2552 if (!trap_state_has_reason(tstate0, per_bc_reason))
2553 maybe_prior_trap = false;
2554 if (!trap_state_is_recompiled(tstate0))
2555 maybe_prior_recompile = false;
2556
2557 // Update the trap state of this profile datum.
2558 int tstate1 = tstate0;
2559 // Record the reason.
2560 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
2561 // Store the updated state on the MDO, for next time.
2562 if (tstate1 != tstate0)
2563 pdata->set_trap_state(tstate1);
2564 } else {
2565 if (LogCompilation && xtty != nullptr) {
2566 ttyLocker ttyl;
2567 // Missing MDP? Leave a small complaint in the log.
2568 xtty->elem("missing_mdp bci='%d'", trap_bci);
2569 }
2570 }
2571 }
2572
2573 // Return results:
2574 ret_this_trap_count = this_trap_count;
2575 ret_maybe_prior_trap = maybe_prior_trap;
2576 ret_maybe_prior_recompile = maybe_prior_recompile;
2577 return pdata;
2578 }
2579
2580 void
2581 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2582 ResourceMark rm;
2583 // Ignored outputs:
2584 uint ignore_this_trap_count;
2585 bool ignore_maybe_prior_trap;
2586 bool ignore_maybe_prior_recompile;
2587 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
2588 // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
2589 bool update_total_counts = true JVMCI_ONLY( && !UseJVMCICompiler);
2590
2591 // Lock to read ProfileData, and ensure lock is not broken by a safepoint
2592 MutexLocker ml(trap_mdo->extra_data_lock(), Mutex::_no_safepoint_check_flag);
2593
2594 query_update_method_data(trap_mdo, trap_bci,
2595 (DeoptReason)reason,
2596 update_total_counts,
2597 #if INCLUDE_JVMCI
2598 false,
2599 #endif
2600 nullptr,
2601 ignore_this_trap_count,
2602 ignore_maybe_prior_trap,
2603 ignore_maybe_prior_recompile);
2604 }
2605
2606 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* current, jint trap_request, jint exec_mode) {
2607 // Enable WXWrite: current function is called from methods compiled by C2 directly
2608 MACOS_AARCH64_ONLY(ThreadWXEnable wx(WXWrite, current));
2609
2610 // Still in Java no safepoints
2611 {
2612 // This enters VM and may safepoint
2613 uncommon_trap_inner(current, trap_request);
2614 }
2615 HandleMark hm(current);
2616 return fetch_unroll_info_helper(current, exec_mode);
2617 }
2618
2619 // Local derived constants.
2620 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2621 const int DS_REASON_MASK = ((uint)DataLayout::trap_mask) >> 1;
2622 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2623
2624 //---------------------------trap_state_reason---------------------------------
2625 Deoptimization::DeoptReason
2626 Deoptimization::trap_state_reason(int trap_state) {
2627 // This assert provides the link between the width of DataLayout::trap_bits
2628 // and the encoding of "recorded" reasons. It ensures there are enough
2629 // bits to store all needed reasons in the per-BCI MDO profile.
2630 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2631 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2632 trap_state -= recompile_bit;
2633 if (trap_state == DS_REASON_MASK) {
2634 return Reason_many;
2635 } else {
2636 assert((int)Reason_none == 0, "state=0 => Reason_none");
2637 return (DeoptReason)trap_state;
2638 }
2639 }
2640 //-------------------------trap_state_has_reason-------------------------------
2641 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2642 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2643 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2644 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2645 trap_state -= recompile_bit;
2646 if (trap_state == DS_REASON_MASK) {
2647 return -1; // true, unspecifically (bottom of state lattice)
2648 } else if (trap_state == reason) {
2649 return 1; // true, definitely
2650 } else if (trap_state == 0) {
2651 return 0; // false, definitely (top of state lattice)
2652 } else {
2653 return 0; // false, definitely
2654 }
2655 }
2656 //-------------------------trap_state_add_reason-------------------------------
2657 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2658 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2659 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2660 trap_state -= recompile_bit;
2661 if (trap_state == DS_REASON_MASK) {
2662 return trap_state + recompile_bit; // already at state lattice bottom
2663 } else if (trap_state == reason) {
2664 return trap_state + recompile_bit; // the condition is already true
2665 } else if (trap_state == 0) {
2666 return reason + recompile_bit; // no condition has yet been true
2667 } else {
2668 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
2669 }
2670 }
2671 //-----------------------trap_state_is_recompiled------------------------------
2672 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2673 return (trap_state & DS_RECOMPILE_BIT) != 0;
2674 }
2675 //-----------------------trap_state_set_recompiled-----------------------------
2676 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2677 if (z) return trap_state | DS_RECOMPILE_BIT;
2678 else return trap_state & ~DS_RECOMPILE_BIT;
2679 }
2680 //---------------------------format_trap_state---------------------------------
2681 // This is used for debugging and diagnostics, including LogFile output.
2682 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2683 int trap_state) {
2684 assert(buflen > 0, "sanity");
2685 DeoptReason reason = trap_state_reason(trap_state);
2686 bool recomp_flag = trap_state_is_recompiled(trap_state);
2687 // Re-encode the state from its decoded components.
2688 int decoded_state = 0;
2689 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2690 decoded_state = trap_state_add_reason(decoded_state, reason);
2691 if (recomp_flag)
2692 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2693 // If the state re-encodes properly, format it symbolically.
2694 // Because this routine is used for debugging and diagnostics,
2695 // be robust even if the state is a strange value.
2696 size_t len;
2697 if (decoded_state != trap_state) {
2698 // Random buggy state that doesn't decode??
2699 len = jio_snprintf(buf, buflen, "#%d", trap_state);
2700 } else {
2701 len = jio_snprintf(buf, buflen, "%s%s",
2702 trap_reason_name(reason),
2703 recomp_flag ? " recompiled" : "");
2704 }
2705 return buf;
2706 }
2707
2708
2709 //--------------------------------statics--------------------------------------
2710 const char* Deoptimization::_trap_reason_name[] = {
2711 // Note: Keep this in sync. with enum DeoptReason.
2712 "none",
2713 "null_check",
2714 "null_assert" JVMCI_ONLY("_or_unreached0"),
2715 "range_check",
2716 "class_check",
2717 "array_check",
2718 "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2719 "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2720 "profile_predicate",
2721 "unloaded",
2722 "uninitialized",
2723 "initialized",
2724 "unreached",
2725 "unhandled",
2726 "constraint",
2727 "div0_check",
2728 "age",
2729 "predicate",
2730 "loop_limit_check",
2731 "speculate_class_check",
2732 "speculate_null_check",
2733 "speculate_null_assert",
2734 "unstable_if",
2735 "unstable_fused_if",
2736 "receiver_constraint",
2737 #if INCLUDE_JVMCI
2738 "aliasing",
2739 "transfer_to_interpreter",
2740 "not_compiled_exception_handler",
2741 "unresolved",
2742 "jsr_mismatch",
2743 #endif
2744 "tenured"
2745 };
2746 const char* Deoptimization::_trap_action_name[] = {
2747 // Note: Keep this in sync. with enum DeoptAction.
2748 "none",
2749 "maybe_recompile",
2750 "reinterpret",
2751 "make_not_entrant",
2752 "make_not_compilable"
2753 };
2754
2755 const char* Deoptimization::trap_reason_name(int reason) {
2756 // Check that every reason has a name
2757 STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2758
2759 if (reason == Reason_many) return "many";
2760 if ((uint)reason < Reason_LIMIT)
2761 return _trap_reason_name[reason];
2762 static char buf[20];
2763 os::snprintf_checked(buf, sizeof(buf), "reason%d", reason);
2764 return buf;
2765 }
2766 const char* Deoptimization::trap_action_name(int action) {
2767 // Check that every action has a name
2768 STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2769
2770 if ((uint)action < Action_LIMIT)
2771 return _trap_action_name[action];
2772 static char buf[20];
2773 os::snprintf_checked(buf, sizeof(buf), "action%d", action);
2774 return buf;
2775 }
2776
2777 // This is used for debugging and diagnostics, including LogFile output.
2778 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2779 int trap_request) {
2780 jint unloaded_class_index = trap_request_index(trap_request);
2781 const char* reason = trap_reason_name(trap_request_reason(trap_request));
2782 const char* action = trap_action_name(trap_request_action(trap_request));
2783 #if INCLUDE_JVMCI
2784 int debug_id = trap_request_debug_id(trap_request);
2785 #endif
2786 size_t len;
2787 if (unloaded_class_index < 0) {
2788 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2789 reason, action
2790 #if INCLUDE_JVMCI
2791 ,debug_id
2792 #endif
2793 );
2794 } else {
2795 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2796 reason, action, unloaded_class_index
2797 #if INCLUDE_JVMCI
2798 ,debug_id
2799 #endif
2800 );
2801 }
2802 return buf;
2803 }
2804
2805 juint Deoptimization::_deoptimization_hist
2806 [Deoptimization::Reason_LIMIT]
2807 [1 + Deoptimization::Action_LIMIT]
2808 [Deoptimization::BC_CASE_LIMIT]
2809 = {0};
2810
2811 enum {
2812 LSB_BITS = 8,
2813 LSB_MASK = right_n_bits(LSB_BITS)
2814 };
2815
2816 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2817 Bytecodes::Code bc) {
2818 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2819 assert(action >= 0 && action < Action_LIMIT, "oob");
2820 _deoptimization_hist[Reason_none][0][0] += 1; // total
2821 _deoptimization_hist[reason][0][0] += 1; // per-reason total
2822 juint* cases = _deoptimization_hist[reason][1+action];
2823 juint* bc_counter_addr = nullptr;
2824 juint bc_counter = 0;
2825 // Look for an unused counter, or an exact match to this BC.
2826 if (bc != Bytecodes::_illegal) {
2827 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2828 juint* counter_addr = &cases[bc_case];
2829 juint counter = *counter_addr;
2830 if ((counter == 0 && bc_counter_addr == nullptr)
2831 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2832 // this counter is either free or is already devoted to this BC
2833 bc_counter_addr = counter_addr;
2834 bc_counter = counter | bc;
2835 }
2836 }
2837 }
2838 if (bc_counter_addr == nullptr) {
2839 // Overflow, or no given bytecode.
2840 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2841 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
2842 }
2843 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2844 }
2845
2846 jint Deoptimization::total_deoptimization_count() {
2847 return _deoptimization_hist[Reason_none][0][0];
2848 }
2849
2850 // Get the deopt count for a specific reason and a specific action. If either
2851 // one of 'reason' or 'action' is null, the method returns the sum of all
2852 // deoptimizations with the specific 'action' or 'reason' respectively.
2853 // If both arguments are null, the method returns the total deopt count.
2854 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2855 if (reason_str == nullptr && action_str == nullptr) {
2856 return total_deoptimization_count();
2857 }
2858 juint counter = 0;
2859 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2860 if (reason_str == nullptr || !strcmp(reason_str, trap_reason_name(reason))) {
2861 for (int action = 0; action < Action_LIMIT; action++) {
2862 if (action_str == nullptr || !strcmp(action_str, trap_action_name(action))) {
2863 juint* cases = _deoptimization_hist[reason][1+action];
2864 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2865 counter += cases[bc_case] >> LSB_BITS;
2866 }
2867 }
2868 }
2869 }
2870 }
2871 return counter;
2872 }
2873
2874 void Deoptimization::print_statistics() {
2875 juint total = total_deoptimization_count();
2876 juint account = total;
2877 if (total != 0) {
2878 ttyLocker ttyl;
2879 if (xtty != nullptr) xtty->head("statistics type='deoptimization'");
2880 tty->print_cr("Deoptimization traps recorded:");
2881 #define PRINT_STAT_LINE(name, r) \
2882 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2883 PRINT_STAT_LINE("total", total);
2884 // For each non-zero entry in the histogram, print the reason,
2885 // the action, and (if specifically known) the type of bytecode.
2886 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2887 for (int action = 0; action < Action_LIMIT; action++) {
2888 juint* cases = _deoptimization_hist[reason][1+action];
2889 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2890 juint counter = cases[bc_case];
2891 if (counter != 0) {
2892 char name[1*K];
2893 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2894 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2895 bc = Bytecodes::_illegal;
2896 os::snprintf_checked(name, sizeof(name), "%s/%s/%s",
2897 trap_reason_name(reason),
2898 trap_action_name(action),
2899 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2900 juint r = counter >> LSB_BITS;
2901 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2902 account -= r;
2903 }
2904 }
2905 }
2906 }
2907 if (account != 0) {
2908 PRINT_STAT_LINE("unaccounted", account);
2909 }
2910 #undef PRINT_STAT_LINE
2911 if (xtty != nullptr) xtty->tail("statistics");
2912 }
2913 }
2914
2915 #else // COMPILER2_OR_JVMCI
2916
2917
2918 // Stubs for C1 only system.
2919 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2920 return false;
2921 }
2922
2923 const char* Deoptimization::trap_reason_name(int reason) {
2924 return "unknown";
2925 }
2926
2927 jint Deoptimization::total_deoptimization_count() {
2928 return 0;
2929 }
2930
2931 jint Deoptimization::deoptimization_count(const char *reason_str, const char *action_str) {
2932 return 0;
2933 }
2934
2935 void Deoptimization::print_statistics() {
2936 // no output
2937 }
2938
2939 void
2940 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2941 // no update
2942 }
2943
2944 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2945 return 0;
2946 }
2947
2948 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2949 Bytecodes::Code bc) {
2950 // no update
2951 }
2952
2953 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2954 int trap_state) {
2955 jio_snprintf(buf, buflen, "#%d", trap_state);
2956 return buf;
2957 }
2958
2959 #endif // COMPILER2_OR_JVMCI