1 /*
2 * Copyright (c) 1997, 2014, 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/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/method.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef TARGET_ARCH_arm
63 # include "vmreg_arm.inline.hpp"
64 #endif
65 #ifdef TARGET_ARCH_ppc
66 # include "vmreg_ppc.inline.hpp"
67 #endif
68 #ifdef COMPILER2
69 #ifdef TARGET_ARCH_MODEL_x86_32
70 # include "adfiles/ad_x86_32.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_x86_64
73 # include "adfiles/ad_x86_64.hpp"
74 #endif
75 #ifdef TARGET_ARCH_MODEL_sparc
76 # include "adfiles/ad_sparc.hpp"
77 #endif
78 #ifdef TARGET_ARCH_MODEL_zero
79 # include "adfiles/ad_zero.hpp"
80 #endif
81 #ifdef TARGET_ARCH_MODEL_arm
82 # include "adfiles/ad_arm.hpp"
83 #endif
84 #ifdef TARGET_ARCH_MODEL_ppc_32
85 # include "adfiles/ad_ppc_32.hpp"
86 #endif
87 #ifdef TARGET_ARCH_MODEL_ppc_64
88 # include "adfiles/ad_ppc_64.hpp"
89 #endif
90 #endif // COMPILER2
91
92 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
93
94 bool DeoptimizationMarker::_is_active = false;
95
96 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
97 int caller_adjustment,
98 int caller_actual_parameters,
99 int number_of_frames,
100 intptr_t* frame_sizes,
101 address* frame_pcs,
102 BasicType return_type) {
103 _size_of_deoptimized_frame = size_of_deoptimized_frame;
104 _caller_adjustment = caller_adjustment;
105 _caller_actual_parameters = caller_actual_parameters;
106 _number_of_frames = number_of_frames;
107 _frame_sizes = frame_sizes;
108 _frame_pcs = frame_pcs;
109 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
110 _return_type = return_type;
111 _initial_info = 0;
112 // PD (x86 only)
113 _counter_temp = 0;
114 _unpack_kind = 0;
115 _sender_sp_temp = 0;
116
117 _total_frame_sizes = size_of_frames();
118 }
119
120
121 Deoptimization::UnrollBlock::~UnrollBlock() {
122 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
123 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
124 FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
125 }
126
127
128 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
129 assert(register_number < RegisterMap::reg_count, "checking register number");
130 return &_register_block[register_number * 2];
131 }
132
133
134
135 int Deoptimization::UnrollBlock::size_of_frames() const {
136 // Acount first for the adjustment of the initial frame
137 int result = _caller_adjustment;
138 for (int index = 0; index < number_of_frames(); index++) {
139 result += frame_sizes()[index];
140 }
141 return result;
142 }
143
144
145 void Deoptimization::UnrollBlock::print() {
146 ttyLocker ttyl;
147 tty->print_cr("UnrollBlock");
148 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
149 tty->print( " frame_sizes: ");
150 for (int index = 0; index < number_of_frames(); index++) {
151 tty->print("%d ", frame_sizes()[index]);
152 }
153 tty->cr();
154 }
155
156
157 // In order to make fetch_unroll_info work properly with escape
158 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
159 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
160 // of previously eliminated objects occurs in realloc_objects, which is
161 // called from the method fetch_unroll_info_helper below.
162 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
163 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
164 // but makes the entry a little slower. There is however a little dance we have to
165 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
166
167 // fetch_unroll_info() is called at the beginning of the deoptimization
168 // handler. Note this fact before we start generating temporary frames
169 // that can confuse an asynchronous stack walker. This counter is
170 // decremented at the end of unpack_frames().
171 thread->inc_in_deopt_handler();
172
173 return fetch_unroll_info_helper(thread);
174 JRT_END
175
176
177 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
178 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
179
180 // Note: there is a safepoint safety issue here. No matter whether we enter
181 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
182 // the vframeArray is created.
183 //
184
185 // Allocate our special deoptimization ResourceMark
186 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
187 assert(thread->deopt_mark() == NULL, "Pending deopt!");
188 thread->set_deopt_mark(dmark);
189
190 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
191 RegisterMap map(thread, true);
192 RegisterMap dummy_map(thread, false);
193 // Now get the deoptee with a valid map
194 frame deoptee = stub_frame.sender(&map);
195 // Set the deoptee nmethod
196 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
197 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
198
199 if (VerifyStack) {
200 thread->validate_frame_layout();
201 }
202
203 // Create a growable array of VFrames where each VFrame represents an inlined
204 // Java frame. This storage is allocated with the usual system arena.
205 assert(deoptee.is_compiled_frame(), "Wrong frame type");
206 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
207 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
208 while (!vf->is_top()) {
209 assert(vf->is_compiled_frame(), "Wrong frame type");
210 chunk->push(compiledVFrame::cast(vf));
211 vf = vf->sender();
212 }
213 assert(vf->is_compiled_frame(), "Wrong frame type");
214 chunk->push(compiledVFrame::cast(vf));
215
216 bool realloc_failures = false;
217
218 #ifdef COMPILER2
219 // Reallocate the non-escaping objects and restore their fields. Then
220 // relock objects if synchronization on them was eliminated.
221 if (DoEscapeAnalysis || EliminateNestedLocks) {
222 if (EliminateAllocations) {
223 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
224 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
225
226 // The flag return_oop() indicates call sites which return oop
227 // in compiled code. Such sites include java method calls,
228 // runtime calls (for example, used to allocate new objects/arrays
229 // on slow code path) and any other calls generated in compiled code.
230 // It is not guaranteed that we can get such information here only
231 // by analyzing bytecode in deoptimized frames. This is why this flag
232 // is set during method compilation (see Compile::Process_OopMap_Node()).
233 // If the previous frame was popped, we don't have a result.
234 bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution();
235 Handle return_value;
236 if (save_oop_result) {
237 // Reallocation may trigger GC. If deoptimization happened on return from
238 // call which returns oop we need to save it since it is not in oopmap.
239 oop result = deoptee.saved_oop_result(&map);
240 assert(result == NULL || result->is_oop(), "must be oop");
241 return_value = Handle(thread, result);
242 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
243 if (TraceDeoptimization) {
244 ttyLocker ttyl;
245 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
246 }
247 }
248 if (objects != NULL) {
249 JRT_BLOCK
250 realloc_failures = realloc_objects(thread, &deoptee, objects, THREAD);
251 JRT_END
252 reassign_fields(&deoptee, &map, objects, realloc_failures);
253 #ifndef PRODUCT
254 if (TraceDeoptimization) {
255 ttyLocker ttyl;
256 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
257 print_objects(objects, realloc_failures);
258 }
259 #endif
260 }
261 if (save_oop_result) {
262 // Restore result.
263 deoptee.set_saved_oop_result(&map, return_value());
264 }
265 }
266 if (EliminateLocks) {
267 #ifndef PRODUCT
268 bool first = true;
269 #endif
270 for (int i = 0; i < chunk->length(); i++) {
271 compiledVFrame* cvf = chunk->at(i);
272 assert (cvf->scope() != NULL,"expect only compiled java frames");
273 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
274 if (monitors->is_nonempty()) {
275 relock_objects(monitors, thread, realloc_failures);
276 #ifndef PRODUCT
277 if (TraceDeoptimization) {
278 ttyLocker ttyl;
279 for (int j = 0; j < monitors->length(); j++) {
280 MonitorInfo* mi = monitors->at(j);
281 if (mi->eliminated()) {
282 if (first) {
283 first = false;
284 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
285 }
286 if (mi->owner_is_scalar_replaced()) {
287 Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
288 tty->print_cr(" failed reallocation for klass %s", k->external_name());
289 } else {
290 tty->print_cr(" object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
291 }
292 }
293 }
294 }
295 #endif
296 }
297 }
298 }
299 }
300 #endif // COMPILER2
301 // Ensure that no safepoint is taken after pointers have been stored
302 // in fields of rematerialized objects. If a safepoint occurs from here on
303 // out the java state residing in the vframeArray will be missed.
304 No_Safepoint_Verifier no_safepoint;
305
306 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk, realloc_failures);
307 #ifdef COMPILER2
308 if (realloc_failures) {
309 pop_frames_failed_reallocs(thread, array);
310 }
311 #endif
312
313 assert(thread->vframe_array_head() == NULL, "Pending deopt!");
314 thread->set_vframe_array_head(array);
315
316 // Now that the vframeArray has been created if we have any deferred local writes
317 // added by jvmti then we can free up that structure as the data is now in the
318 // vframeArray
319
320 if (thread->deferred_locals() != NULL) {
321 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
322 int i = 0;
323 do {
324 // Because of inlining we could have multiple vframes for a single frame
325 // and several of the vframes could have deferred writes. Find them all.
326 if (list->at(i)->id() == array->original().id()) {
327 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
328 list->remove_at(i);
329 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
330 delete dlv;
331 } else {
332 i++;
333 }
334 } while ( i < list->length() );
335 if (list->length() == 0) {
336 thread->set_deferred_locals(NULL);
337 // free the list and elements back to C heap.
338 delete list;
339 }
340
341 }
342
343 #ifndef SHARK
344 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
345 CodeBlob* cb = stub_frame.cb();
346 // Verify we have the right vframeArray
347 assert(cb->frame_size() >= 0, "Unexpected frame size");
348 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
349
350 // If the deopt call site is a MethodHandle invoke call site we have
351 // to adjust the unpack_sp.
352 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
353 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
354 unpack_sp = deoptee.unextended_sp();
355
356 #ifdef ASSERT
357 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
358 #endif
359 #else
360 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
361 #endif // !SHARK
362
363 // This is a guarantee instead of an assert because if vframe doesn't match
364 // we will unpack the wrong deoptimized frame and wind up in strange places
365 // where it will be very difficult to figure out what went wrong. Better
366 // to die an early death here than some very obscure death later when the
367 // trail is cold.
368 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
369 // in that it will fail to detect a problem when there is one. This needs
370 // more work in tiger timeframe.
371 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
372
373 int number_of_frames = array->frames();
374
375 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
376 // virtual activation, which is the reverse of the elements in the vframes array.
377 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
378 // +1 because we always have an interpreter return address for the final slot.
379 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
380 int popframe_extra_args = 0;
381 // Create an interpreter return address for the stub to use as its return
382 // address so the skeletal frames are perfectly walkable
383 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
384
385 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
386 // activation be put back on the expression stack of the caller for reexecution
387 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
388 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
389 }
390
391 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
392 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
393 // than simply use array->sender.pc(). This requires us to walk the current set of frames
394 //
395 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
396 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
397
398 // It's possible that the number of paramters at the call site is
399 // different than number of arguments in the callee when method
400 // handles are used. If the caller is interpreted get the real
401 // value so that the proper amount of space can be added to it's
402 // frame.
403 bool caller_was_method_handle = false;
404 if (deopt_sender.is_interpreted_frame()) {
405 methodHandle method = deopt_sender.interpreter_frame_method();
406 Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
407 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
408 // Method handle invokes may involve fairly arbitrary chains of
409 // calls so it's impossible to know how much actual space the
410 // caller has for locals.
411 caller_was_method_handle = true;
412 }
413 }
414
415 //
416 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
417 // frame_sizes/frame_pcs[1] next oldest frame (int)
418 // frame_sizes/frame_pcs[n] youngest frame (int)
419 //
420 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
421 // owns the space for the return address to it's caller). Confusing ain't it.
422 //
423 // The vframe array can address vframes with indices running from
424 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
425 // When we create the skeletal frames we need the oldest frame to be in the zero slot
426 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
427 // so things look a little strange in this loop.
428 //
429 int callee_parameters = 0;
430 int callee_locals = 0;
431 for (int index = 0; index < array->frames(); index++ ) {
432 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
433 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
434 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
435 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
436 callee_locals,
437 index == 0,
438 popframe_extra_args);
439 // This pc doesn't have to be perfect just good enough to identify the frame
440 // as interpreted so the skeleton frame will be walkable
441 // The correct pc will be set when the skeleton frame is completely filled out
442 // The final pc we store in the loop is wrong and will be overwritten below
443 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
444
445 callee_parameters = array->element(index)->method()->size_of_parameters();
446 callee_locals = array->element(index)->method()->max_locals();
447 popframe_extra_args = 0;
448 }
449
450 // Compute whether the root vframe returns a float or double value.
451 BasicType return_type;
452 {
453 HandleMark hm;
454 methodHandle method(thread, array->element(0)->method());
455 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
456 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
457 }
458
459 // Compute information for handling adapters and adjusting the frame size of the caller.
460 int caller_adjustment = 0;
461
462 // Compute the amount the oldest interpreter frame will have to adjust
463 // its caller's stack by. If the caller is a compiled frame then
464 // we pretend that the callee has no parameters so that the
465 // extension counts for the full amount of locals and not just
466 // locals-parms. This is because without a c2i adapter the parm
467 // area as created by the compiled frame will not be usable by
468 // the interpreter. (Depending on the calling convention there
469 // may not even be enough space).
470
471 // QQQ I'd rather see this pushed down into last_frame_adjust
472 // and have it take the sender (aka caller).
473
474 if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
475 caller_adjustment = last_frame_adjust(0, callee_locals);
476 } else if (callee_locals > callee_parameters) {
477 // The caller frame may need extending to accommodate
478 // non-parameter locals of the first unpacked interpreted frame.
479 // Compute that adjustment.
480 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
481 }
482
483 // If the sender is deoptimized the we must retrieve the address of the handler
484 // since the frame will "magically" show the original pc before the deopt
485 // and we'd undo the deopt.
486
487 frame_pcs[0] = deopt_sender.raw_pc();
488
489 #ifndef SHARK
490 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
491 #endif // SHARK
492
493 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
494 caller_adjustment * BytesPerWord,
495 caller_was_method_handle ? 0 : callee_parameters,
496 number_of_frames,
497 frame_sizes,
498 frame_pcs,
499 return_type);
500 // On some platforms, we need a way to pass some platform dependent
501 // information to the unpacking code so the skeletal frames come out
502 // correct (initial fp value, unextended sp, ...)
503 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
504
505 if (array->frames() > 1) {
506 if (VerifyStack && TraceDeoptimization) {
507 ttyLocker ttyl;
508 tty->print_cr("Deoptimizing method containing inlining");
509 }
510 }
511
512 array->set_unroll_block(info);
513 return info;
514 }
515
516 // Called to cleanup deoptimization data structures in normal case
517 // after unpacking to stack and when stack overflow error occurs
518 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
519 vframeArray *array) {
520
521 // Get array if coming from exception
522 if (array == NULL) {
523 array = thread->vframe_array_head();
524 }
525 thread->set_vframe_array_head(NULL);
526
527 // Free the previous UnrollBlock
528 vframeArray* old_array = thread->vframe_array_last();
529 thread->set_vframe_array_last(array);
530
531 if (old_array != NULL) {
532 UnrollBlock* old_info = old_array->unroll_block();
533 old_array->set_unroll_block(NULL);
534 delete old_info;
535 delete old_array;
536 }
537
538 // Deallocate any resource creating in this routine and any ResourceObjs allocated
539 // inside the vframeArray (StackValueCollections)
540
541 delete thread->deopt_mark();
542 thread->set_deopt_mark(NULL);
543 thread->set_deopt_nmethod(NULL);
544
545
546 if (JvmtiExport::can_pop_frame()) {
547 #ifndef CC_INTERP
548 // Regardless of whether we entered this routine with the pending
549 // popframe condition bit set, we should always clear it now
550 thread->clear_popframe_condition();
551 #else
552 // C++ interpeter will clear has_pending_popframe when it enters
553 // with method_resume. For deopt_resume2 we clear it now.
554 if (thread->popframe_forcing_deopt_reexecution())
555 thread->clear_popframe_condition();
556 #endif /* CC_INTERP */
557 }
558
559 // unpack_frames() is called at the end of the deoptimization handler
560 // and (in C2) at the end of the uncommon trap handler. Note this fact
561 // so that an asynchronous stack walker can work again. This counter is
562 // incremented at the beginning of fetch_unroll_info() and (in C2) at
563 // the beginning of uncommon_trap().
564 thread->dec_in_deopt_handler();
565 }
566
567
568 // Return BasicType of value being returned
569 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
570
571 // We are already active int he special DeoptResourceMark any ResourceObj's we
572 // allocate will be freed at the end of the routine.
573
574 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
575 // but makes the entry a little slower. There is however a little dance we have to
576 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
577 ResetNoHandleMark rnhm; // No-op in release/product versions
578 HandleMark hm;
579
580 frame stub_frame = thread->last_frame();
581
582 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
583 // must point to the vframeArray for the unpack frame.
584 vframeArray* array = thread->vframe_array_head();
585
586 #ifndef PRODUCT
587 if (TraceDeoptimization) {
588 ttyLocker ttyl;
589 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
590 }
591 #endif
592 Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
593 stub_frame.pc(), stub_frame.sp(), exec_mode);
594
595 UnrollBlock* info = array->unroll_block();
596
597 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
598 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
599
600 BasicType bt = info->return_type();
601
602 // If we have an exception pending, claim that the return type is an oop
603 // so the deopt_blob does not overwrite the exception_oop.
604
605 if (exec_mode == Unpack_exception)
606 bt = T_OBJECT;
607
608 // Cleanup thread deopt data
609 cleanup_deopt_info(thread, array);
610
611 #ifndef PRODUCT
612 if (VerifyStack) {
613 ResourceMark res_mark;
614
615 thread->validate_frame_layout();
616
617 // Verify that the just-unpacked frames match the interpreter's
618 // notions of expression stack and locals
619 vframeArray* cur_array = thread->vframe_array_last();
620 RegisterMap rm(thread, false);
621 rm.set_include_argument_oops(false);
622 bool is_top_frame = true;
623 int callee_size_of_parameters = 0;
624 int callee_max_locals = 0;
625 for (int i = 0; i < cur_array->frames(); i++) {
626 vframeArrayElement* el = cur_array->element(i);
627 frame* iframe = el->iframe();
628 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
629
630 // Get the oop map for this bci
631 InterpreterOopMap mask;
632 int cur_invoke_parameter_size = 0;
633 bool try_next_mask = false;
634 int next_mask_expression_stack_size = -1;
635 int top_frame_expression_stack_adjustment = 0;
636 methodHandle mh(thread, iframe->interpreter_frame_method());
637 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
638 BytecodeStream str(mh);
639 str.set_start(iframe->interpreter_frame_bci());
640 int max_bci = mh->code_size();
641 // Get to the next bytecode if possible
642 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
643 // Check to see if we can grab the number of outgoing arguments
644 // at an uncommon trap for an invoke (where the compiler
645 // generates debug info before the invoke has executed)
646 Bytecodes::Code cur_code = str.next();
647 if (cur_code == Bytecodes::_invokevirtual ||
648 cur_code == Bytecodes::_invokespecial ||
649 cur_code == Bytecodes::_invokestatic ||
650 cur_code == Bytecodes::_invokeinterface ||
651 cur_code == Bytecodes::_invokedynamic) {
652 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
653 Symbol* signature = invoke.signature();
654 ArgumentSizeComputer asc(signature);
655 cur_invoke_parameter_size = asc.size();
656 if (invoke.has_receiver()) {
657 // Add in receiver
658 ++cur_invoke_parameter_size;
659 }
660 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
661 callee_size_of_parameters++;
662 }
663 }
664 if (str.bci() < max_bci) {
665 Bytecodes::Code bc = str.next();
666 if (bc >= 0) {
667 // The interpreter oop map generator reports results before
668 // the current bytecode has executed except in the case of
669 // calls. It seems to be hard to tell whether the compiler
670 // has emitted debug information matching the "state before"
671 // a given bytecode or the state after, so we try both
672 switch (cur_code) {
673 case Bytecodes::_invokevirtual:
674 case Bytecodes::_invokespecial:
675 case Bytecodes::_invokestatic:
676 case Bytecodes::_invokeinterface:
677 case Bytecodes::_invokedynamic:
678 case Bytecodes::_athrow:
679 break;
680 default: {
681 InterpreterOopMap next_mask;
682 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
683 next_mask_expression_stack_size = next_mask.expression_stack_size();
684 // Need to subtract off the size of the result type of
685 // the bytecode because this is not described in the
686 // debug info but returned to the interpreter in the TOS
687 // caching register
688 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
689 if (bytecode_result_type != T_ILLEGAL) {
690 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
691 }
692 assert(top_frame_expression_stack_adjustment >= 0, "");
693 try_next_mask = true;
694 break;
695 }
696 }
697 }
698 }
699
700 // Verify stack depth and oops in frame
701 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
702 if (!(
703 /* SPARC */
704 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
705 /* x86 */
706 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
707 (try_next_mask &&
708 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
709 top_frame_expression_stack_adjustment))) ||
710 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
711 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
712 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
713 )) {
714 ttyLocker ttyl;
715
716 // Print out some information that will help us debug the problem
717 tty->print_cr("Wrong number of expression stack elements during deoptimization");
718 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
719 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
720 iframe->interpreter_frame_expression_stack_size());
721 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
722 tty->print_cr(" try_next_mask = %d", try_next_mask);
723 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
724 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
725 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
726 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
727 tty->print_cr(" exec_mode = %d", exec_mode);
728 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
729 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
730 tty->print_cr(" Interpreted frames:");
731 for (int k = 0; k < cur_array->frames(); k++) {
732 vframeArrayElement* el = cur_array->element(k);
733 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
734 }
735 cur_array->print_on_2(tty);
736 guarantee(false, "wrong number of expression stack elements during deopt");
737 }
738 VerifyOopClosure verify;
739 iframe->oops_interpreted_do(&verify, NULL, &rm, false);
740 callee_size_of_parameters = mh->size_of_parameters();
741 callee_max_locals = mh->max_locals();
742 is_top_frame = false;
743 }
744 }
745 #endif /* !PRODUCT */
746
747
748 return bt;
749 JRT_END
750
751
752 int Deoptimization::deoptimize_dependents() {
753 Threads::deoptimized_wrt_marked_nmethods();
754 return 0;
755 }
756
757
758 #ifdef COMPILER2
759 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
760 Handle pending_exception(thread->pending_exception());
761 const char* exception_file = thread->exception_file();
762 int exception_line = thread->exception_line();
763 thread->clear_pending_exception();
764
765 bool failures = false;
766
767 for (int i = 0; i < objects->length(); i++) {
768 assert(objects->at(i)->is_object(), "invalid debug information");
769 ObjectValue* sv = (ObjectValue*) objects->at(i);
770
771 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
772 oop obj = NULL;
773
774 if (k->oop_is_instance()) {
775 InstanceKlass* ik = InstanceKlass::cast(k());
776 obj = ik->allocate_instance(THREAD);
777 } else if (k->oop_is_typeArray()) {
778 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
779 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
780 int len = sv->field_size() / type2size[ak->element_type()];
781 obj = ak->allocate(len, THREAD);
782 } else if (k->oop_is_objArray()) {
783 ObjArrayKlass* ak = ObjArrayKlass::cast(k());
784 obj = ak->allocate(sv->field_size(), THREAD);
785 }
786
787 if (obj == NULL) {
788 failures = true;
789 }
790
791 assert(sv->value().is_null(), "redundant reallocation");
792 assert(obj != NULL || HAS_PENDING_EXCEPTION, "allocation should succeed or we should get an exception");
793 CLEAR_PENDING_EXCEPTION;
794 sv->set_value(obj);
795 }
796
797 if (failures) {
798 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
799 } else if (pending_exception.not_null()) {
800 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
801 }
802
803 return failures;
804 }
805
806 // This assumes that the fields are stored in ObjectValue in the same order
807 // they are yielded by do_nonstatic_fields.
808 class FieldReassigner: public FieldClosure {
809 frame* _fr;
810 RegisterMap* _reg_map;
811 ObjectValue* _sv;
812 InstanceKlass* _ik;
813 oop _obj;
814
815 int _i;
816 public:
817 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
818 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
819
820 int i() const { return _i; }
821
822
823 void do_field(fieldDescriptor* fd) {
824 intptr_t val;
825 StackValue* value =
826 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
827 int offset = fd->offset();
828 switch (fd->field_type()) {
829 case T_OBJECT: case T_ARRAY:
830 assert(value->type() == T_OBJECT, "Agreement.");
831 _obj->obj_field_put(offset, value->get_obj()());
832 break;
833
834 case T_LONG: case T_DOUBLE: {
835 assert(value->type() == T_INT, "Agreement.");
836 StackValue* low =
837 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
838 #ifdef _LP64
839 jlong res = (jlong)low->get_int();
840 #else
841 #ifdef SPARC
842 // For SPARC we have to swap high and low words.
843 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
844 #else
845 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
846 #endif //SPARC
847 #endif
848 _obj->long_field_put(offset, res);
849 break;
850 }
851 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
852 case T_INT: case T_FLOAT: // 4 bytes.
853 assert(value->type() == T_INT, "Agreement.");
854 val = value->get_int();
855 _obj->int_field_put(offset, (jint)*((jint*)&val));
856 break;
857
858 case T_SHORT: case T_CHAR: // 2 bytes
859 assert(value->type() == T_INT, "Agreement.");
860 val = value->get_int();
861 _obj->short_field_put(offset, (jshort)*((jint*)&val));
862 break;
863
864 case T_BOOLEAN: case T_BYTE: // 1 byte
865 assert(value->type() == T_INT, "Agreement.");
866 val = value->get_int();
867 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
868 break;
869
870 default:
871 ShouldNotReachHere();
872 }
873 _i++;
874 }
875 };
876
877 // restore elements of an eliminated type array
878 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
879 int index = 0;
880 intptr_t val;
881
882 for (int i = 0; i < sv->field_size(); i++) {
883 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
884 switch(type) {
885 case T_LONG: case T_DOUBLE: {
886 assert(value->type() == T_INT, "Agreement.");
887 StackValue* low =
888 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
889 #ifdef _LP64
890 jlong res = (jlong)low->get_int();
891 #else
892 #ifdef SPARC
893 // For SPARC we have to swap high and low words.
894 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
895 #else
896 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
897 #endif //SPARC
898 #endif
899 obj->long_at_put(index, res);
900 break;
901 }
902
903 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
904 case T_INT: case T_FLOAT: // 4 bytes.
905 assert(value->type() == T_INT, "Agreement.");
906 val = value->get_int();
907 obj->int_at_put(index, (jint)*((jint*)&val));
908 break;
909
910 case T_SHORT: case T_CHAR: // 2 bytes
911 assert(value->type() == T_INT, "Agreement.");
912 val = value->get_int();
913 obj->short_at_put(index, (jshort)*((jint*)&val));
914 break;
915
916 case T_BOOLEAN: case T_BYTE: // 1 byte
917 assert(value->type() == T_INT, "Agreement.");
918 val = value->get_int();
919 obj->bool_at_put(index, (jboolean)*((jint*)&val));
920 break;
921
922 default:
923 ShouldNotReachHere();
924 }
925 index++;
926 }
927 }
928
929
930 // restore fields of an eliminated object array
931 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
932 for (int i = 0; i < sv->field_size(); i++) {
933 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
934 assert(value->type() == T_OBJECT, "object element expected");
935 obj->obj_at_put(i, value->get_obj()());
936 }
937 }
938
939
940 // restore fields of all eliminated objects and arrays
941 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
942 for (int i = 0; i < objects->length(); i++) {
943 ObjectValue* sv = (ObjectValue*) objects->at(i);
944 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
945 Handle obj = sv->value();
946 assert(obj.not_null() || realloc_failures, "reallocation was missed");
947 if (obj.is_null()) {
948 continue;
949 }
950
951 if (k->oop_is_instance()) {
952 InstanceKlass* ik = InstanceKlass::cast(k());
953 FieldReassigner reassign(fr, reg_map, sv, obj());
954 ik->do_nonstatic_fields(&reassign);
955 } else if (k->oop_is_typeArray()) {
956 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
957 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
958 } else if (k->oop_is_objArray()) {
959 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
960 }
961 }
962 }
963
964
965 // relock objects for which synchronization was eliminated
966 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures) {
967 for (int i = 0; i < monitors->length(); i++) {
968 MonitorInfo* mon_info = monitors->at(i);
969 if (mon_info->eliminated()) {
970 assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
971 if (!mon_info->owner_is_scalar_replaced()) {
972 Handle obj = Handle(mon_info->owner());
973 markOop mark = obj->mark();
974 if (UseBiasedLocking && mark->has_bias_pattern()) {
975 // New allocated objects may have the mark set to anonymously biased.
976 // Also the deoptimized method may called methods with synchronization
977 // where the thread-local object is bias locked to the current thread.
978 assert(mark->is_biased_anonymously() ||
979 mark->biased_locker() == thread, "should be locked to current thread");
980 // Reset mark word to unbiased prototype.
981 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
982 obj->set_mark(unbiased_prototype);
983 }
984 BasicLock* lock = mon_info->lock();
985 ObjectSynchronizer::slow_enter(obj, lock, thread);
986 assert(mon_info->owner()->is_locked(), "object must be locked now");
987 }
988 }
989 }
990 }
991
992
993 #ifndef PRODUCT
994 // print information about reallocated objects
995 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
996 fieldDescriptor fd;
997
998 for (int i = 0; i < objects->length(); i++) {
999 ObjectValue* sv = (ObjectValue*) objects->at(i);
1000 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
1001 Handle obj = sv->value();
1002
1003 tty->print(" object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
1004 k->print_value();
1005 assert(obj.not_null() || realloc_failures, "reallocation was missed");
1006 if (obj.is_null()) {
1007 tty->print(" allocation failed");
1008 } else {
1009 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
1010 }
1011 tty->cr();
1012
1013 if (Verbose && !obj.is_null()) {
1014 k->oop_print_on(obj(), tty);
1015 }
1016 }
1017 }
1018 #endif
1019 #endif // COMPILER2
1020
1021 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1022 Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
1023
1024 #ifndef PRODUCT
1025 if (TraceDeoptimization) {
1026 ttyLocker ttyl;
1027 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
1028 fr.print_on(tty);
1029 tty->print_cr(" Virtual frames (innermost first):");
1030 for (int index = 0; index < chunk->length(); index++) {
1031 compiledVFrame* vf = chunk->at(index);
1032 tty->print(" %2d - ", index);
1033 vf->print_value();
1034 int bci = chunk->at(index)->raw_bci();
1035 const char* code_name;
1036 if (bci == SynchronizationEntryBCI) {
1037 code_name = "sync entry";
1038 } else {
1039 Bytecodes::Code code = vf->method()->code_at(bci);
1040 code_name = Bytecodes::name(code);
1041 }
1042 tty->print(" - %s", code_name);
1043 tty->print_cr(" @ bci %d ", bci);
1044 if (Verbose) {
1045 vf->print();
1046 tty->cr();
1047 }
1048 }
1049 }
1050 #endif
1051
1052 // Register map for next frame (used for stack crawl). We capture
1053 // the state of the deopt'ing frame's caller. Thus if we need to
1054 // stuff a C2I adapter we can properly fill in the callee-save
1055 // register locations.
1056 frame caller = fr.sender(reg_map);
1057 int frame_size = caller.sp() - fr.sp();
1058
1059 frame sender = caller;
1060
1061 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1062 // the vframeArray containing the unpacking information is allocated in the C heap.
1063 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1064 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1065
1066 // Compare the vframeArray to the collected vframes
1067 assert(array->structural_compare(thread, chunk), "just checking");
1068
1069 #ifndef PRODUCT
1070 if (TraceDeoptimization) {
1071 ttyLocker ttyl;
1072 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1073 }
1074 #endif // PRODUCT
1075
1076 return array;
1077 }
1078
1079 #ifdef COMPILER2
1080 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1081 // Reallocation of some scalar replaced objects failed. Record
1082 // that we need to pop all the interpreter frames for the
1083 // deoptimized compiled frame.
1084 assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1085 thread->set_frames_to_pop_failed_realloc(array->frames());
1086 // Unlock all monitors here otherwise the interpreter will see a
1087 // mix of locked and unlocked monitors (because of failed
1088 // reallocations of synchronized objects) and be confused.
1089 for (int i = 0; i < array->frames(); i++) {
1090 MonitorChunk* monitors = array->element(i)->monitors();
1091 if (monitors != NULL) {
1092 for (int j = 0; j < monitors->number_of_monitors(); j++) {
1093 BasicObjectLock* src = monitors->at(j);
1094 if (src->obj() != NULL) {
1095 ObjectSynchronizer::fast_exit(src->obj(), src->lock(), thread);
1096 }
1097 }
1098 array->element(i)->free_monitors(thread);
1099 #ifdef ASSERT
1100 array->element(i)->set_removed_monitors();
1101 #endif
1102 }
1103 }
1104 }
1105 #endif
1106
1107 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1108 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1109 for (int i = 0; i < monitors->length(); i++) {
1110 MonitorInfo* mon_info = monitors->at(i);
1111 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1112 objects_to_revoke->append(Handle(mon_info->owner()));
1113 }
1114 }
1115 }
1116
1117
1118 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1119 if (!UseBiasedLocking) {
1120 return;
1121 }
1122
1123 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1124
1125 // Unfortunately we don't have a RegisterMap available in most of
1126 // the places we want to call this routine so we need to walk the
1127 // stack again to update the register map.
1128 if (map == NULL || !map->update_map()) {
1129 StackFrameStream sfs(thread, true);
1130 bool found = false;
1131 while (!found && !sfs.is_done()) {
1132 frame* cur = sfs.current();
1133 sfs.next();
1134 found = cur->id() == fr.id();
1135 }
1136 assert(found, "frame to be deoptimized not found on target thread's stack");
1137 map = sfs.register_map();
1138 }
1139
1140 vframe* vf = vframe::new_vframe(&fr, map, thread);
1141 compiledVFrame* cvf = compiledVFrame::cast(vf);
1142 // Revoke monitors' biases in all scopes
1143 while (!cvf->is_top()) {
1144 collect_monitors(cvf, objects_to_revoke);
1145 cvf = compiledVFrame::cast(cvf->sender());
1146 }
1147 collect_monitors(cvf, objects_to_revoke);
1148
1149 if (SafepointSynchronize::is_at_safepoint()) {
1150 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1151 } else {
1152 BiasedLocking::revoke(objects_to_revoke);
1153 }
1154 }
1155
1156
1157 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1158 if (!UseBiasedLocking) {
1159 return;
1160 }
1161
1162 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1163 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1164 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1165 if (jt->has_last_Java_frame()) {
1166 StackFrameStream sfs(jt, true);
1167 while (!sfs.is_done()) {
1168 frame* cur = sfs.current();
1169 if (cb->contains(cur->pc())) {
1170 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1171 compiledVFrame* cvf = compiledVFrame::cast(vf);
1172 // Revoke monitors' biases in all scopes
1173 while (!cvf->is_top()) {
1174 collect_monitors(cvf, objects_to_revoke);
1175 cvf = compiledVFrame::cast(cvf->sender());
1176 }
1177 collect_monitors(cvf, objects_to_revoke);
1178 }
1179 sfs.next();
1180 }
1181 }
1182 }
1183 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1184 }
1185
1186
1187 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1188 assert(fr.can_be_deoptimized(), "checking frame type");
1189
1190 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1191
1192 // Patch the nmethod so that when execution returns to it we will
1193 // deopt the execution state and return to the interpreter.
1194 fr.deoptimize(thread);
1195 }
1196
1197 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1198 // Deoptimize only if the frame comes from compile code.
1199 // Do not deoptimize the frame which is already patched
1200 // during the execution of the loops below.
1201 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1202 return;
1203 }
1204 ResourceMark rm;
1205 DeoptimizationMarker dm;
1206 if (UseBiasedLocking) {
1207 revoke_biases_of_monitors(thread, fr, map);
1208 }
1209 deoptimize_single_frame(thread, fr);
1210
1211 }
1212
1213
1214 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1215 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1216 "can only deoptimize other thread at a safepoint");
1217 // Compute frame and register map based on thread and sp.
1218 RegisterMap reg_map(thread, UseBiasedLocking);
1219 frame fr = thread->last_frame();
1220 while (fr.id() != id) {
1221 fr = fr.sender(®_map);
1222 }
1223 deoptimize(thread, fr, ®_map);
1224 }
1225
1226
1227 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1228 if (thread == Thread::current()) {
1229 Deoptimization::deoptimize_frame_internal(thread, id);
1230 } else {
1231 VM_DeoptimizeFrame deopt(thread, id);
1232 VMThread::execute(&deopt);
1233 }
1234 }
1235
1236
1237 // JVMTI PopFrame support
1238 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1239 {
1240 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1241 }
1242 JRT_END
1243
1244
1245 #if defined(COMPILER2) || defined(SHARK)
1246 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1247 // in case of an unresolved klass entry, load the class.
1248 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1249 Klass* tk = constant_pool->klass_at(index, CHECK);
1250 return;
1251 }
1252
1253 if (!constant_pool->tag_at(index).is_symbol()) return;
1254
1255 Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1256 Symbol* symbol = constant_pool->symbol_at(index);
1257
1258 // class name?
1259 if (symbol->byte_at(0) != '(') {
1260 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1261 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1262 return;
1263 }
1264
1265 // then it must be a signature!
1266 ResourceMark rm(THREAD);
1267 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1268 if (ss.is_object()) {
1269 Symbol* class_name = ss.as_symbol(CHECK);
1270 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1271 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1272 }
1273 }
1274 }
1275
1276
1277 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1278 EXCEPTION_MARK;
1279 load_class_by_index(constant_pool, index, THREAD);
1280 if (HAS_PENDING_EXCEPTION) {
1281 // Exception happened during classloading. We ignore the exception here, since it
1282 // is going to be rethrown since the current activation is going to be deoptimized and
1283 // the interpreter will re-execute the bytecode.
1284 CLEAR_PENDING_EXCEPTION;
1285 // Class loading called java code which may have caused a stack
1286 // overflow. If the exception was thrown right before the return
1287 // to the runtime the stack is no longer guarded. Reguard the
1288 // stack otherwise if we return to the uncommon trap blob and the
1289 // stack bang causes a stack overflow we crash.
1290 assert(THREAD->is_Java_thread(), "only a java thread can be here");
1291 JavaThread* thread = (JavaThread*)THREAD;
1292 bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1293 if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1294 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1295 }
1296 }
1297
1298 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1299 HandleMark hm;
1300
1301 // uncommon_trap() is called at the beginning of the uncommon trap
1302 // handler. Note this fact before we start generating temporary frames
1303 // that can confuse an asynchronous stack walker. This counter is
1304 // decremented at the end of unpack_frames().
1305 thread->inc_in_deopt_handler();
1306
1307 // We need to update the map if we have biased locking.
1308 RegisterMap reg_map(thread, UseBiasedLocking);
1309 frame stub_frame = thread->last_frame();
1310 frame fr = stub_frame.sender(®_map);
1311 // Make sure the calling nmethod is not getting deoptimized and removed
1312 // before we are done with it.
1313 nmethodLocker nl(fr.pc());
1314
1315 // Log a message
1316 Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1317 trap_request, fr.pc());
1318
1319 {
1320 ResourceMark rm;
1321
1322 // Revoke biases of any monitors in the frame to ensure we can migrate them
1323 revoke_biases_of_monitors(thread, fr, ®_map);
1324
1325 DeoptReason reason = trap_request_reason(trap_request);
1326 DeoptAction action = trap_request_action(trap_request);
1327 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1328
1329 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1330 compiledVFrame* cvf = compiledVFrame::cast(vf);
1331
1332 nmethod* nm = cvf->code();
1333
1334 ScopeDesc* trap_scope = cvf->scope();
1335 methodHandle trap_method = trap_scope->method();
1336 int trap_bci = trap_scope->bci();
1337 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1338
1339 // Record this event in the histogram.
1340 gather_statistics(reason, action, trap_bc);
1341
1342 // Ensure that we can record deopt. history:
1343 // Need MDO to record RTM code generation state.
1344 bool create_if_missing = ProfileTraps RTM_OPT_ONLY( || UseRTMLocking );
1345
1346 MethodData* trap_mdo =
1347 get_method_data(thread, trap_method, create_if_missing);
1348
1349 // Log a message
1350 Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1351 trap_reason_name(reason), trap_action_name(action), fr.pc(),
1352 trap_method->name_and_sig_as_C_string(), trap_bci);
1353
1354 // Print a bunch of diagnostics, if requested.
1355 if (TraceDeoptimization || LogCompilation) {
1356 ResourceMark rm;
1357 ttyLocker ttyl;
1358 char buf[100];
1359 if (xtty != NULL) {
1360 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1361 os::current_thread_id(),
1362 format_trap_request(buf, sizeof(buf), trap_request));
1363 nm->log_identity(xtty);
1364 }
1365 Symbol* class_name = NULL;
1366 bool unresolved = false;
1367 if (unloaded_class_index >= 0) {
1368 constantPoolHandle constants (THREAD, trap_method->constants());
1369 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1370 class_name = constants->klass_name_at(unloaded_class_index);
1371 unresolved = true;
1372 if (xtty != NULL)
1373 xtty->print(" unresolved='1'");
1374 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1375 class_name = constants->symbol_at(unloaded_class_index);
1376 }
1377 if (xtty != NULL)
1378 xtty->name(class_name);
1379 }
1380 if (xtty != NULL && trap_mdo != NULL) {
1381 // Dump the relevant MDO state.
1382 // This is the deopt count for the current reason, any previous
1383 // reasons or recompiles seen at this point.
1384 int dcnt = trap_mdo->trap_count(reason);
1385 if (dcnt != 0)
1386 xtty->print(" count='%d'", dcnt);
1387 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1388 int dos = (pdata == NULL)? 0: pdata->trap_state();
1389 if (dos != 0) {
1390 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1391 if (trap_state_is_recompiled(dos)) {
1392 int recnt2 = trap_mdo->overflow_recompile_count();
1393 if (recnt2 != 0)
1394 xtty->print(" recompiles2='%d'", recnt2);
1395 }
1396 }
1397 }
1398 if (xtty != NULL) {
1399 xtty->stamp();
1400 xtty->end_head();
1401 }
1402 if (TraceDeoptimization) { // make noise on the tty
1403 tty->print("Uncommon trap occurred in");
1404 nm->method()->print_short_name(tty);
1405 tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1406 fr.pc(),
1407 os::current_thread_id(),
1408 trap_reason_name(reason),
1409 trap_action_name(action),
1410 unloaded_class_index);
1411 if (class_name != NULL) {
1412 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1413 class_name->print_symbol_on(tty);
1414 }
1415 tty->cr();
1416 }
1417 if (xtty != NULL) {
1418 // Log the precise location of the trap.
1419 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1420 xtty->begin_elem("jvms bci='%d'", sd->bci());
1421 xtty->method(sd->method());
1422 xtty->end_elem();
1423 if (sd->is_top()) break;
1424 }
1425 xtty->tail("uncommon_trap");
1426 }
1427 }
1428 // (End diagnostic printout.)
1429
1430 // Load class if necessary
1431 if (unloaded_class_index >= 0) {
1432 constantPoolHandle constants(THREAD, trap_method->constants());
1433 load_class_by_index(constants, unloaded_class_index);
1434 }
1435
1436 // Flush the nmethod if necessary and desirable.
1437 //
1438 // We need to avoid situations where we are re-flushing the nmethod
1439 // because of a hot deoptimization site. Repeated flushes at the same
1440 // point need to be detected by the compiler and avoided. If the compiler
1441 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1442 // module must take measures to avoid an infinite cycle of recompilation
1443 // and deoptimization. There are several such measures:
1444 //
1445 // 1. If a recompilation is ordered a second time at some site X
1446 // and for the same reason R, the action is adjusted to 'reinterpret',
1447 // to give the interpreter time to exercise the method more thoroughly.
1448 // If this happens, the method's overflow_recompile_count is incremented.
1449 //
1450 // 2. If the compiler fails to reduce the deoptimization rate, then
1451 // the method's overflow_recompile_count will begin to exceed the set
1452 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1453 // is adjusted to 'make_not_compilable', and the method is abandoned
1454 // to the interpreter. This is a performance hit for hot methods,
1455 // but is better than a disastrous infinite cycle of recompilations.
1456 // (Actually, only the method containing the site X is abandoned.)
1457 //
1458 // 3. In parallel with the previous measures, if the total number of
1459 // recompilations of a method exceeds the much larger set limit
1460 // PerMethodRecompilationCutoff, the method is abandoned.
1461 // This should only happen if the method is very large and has
1462 // many "lukewarm" deoptimizations. The code which enforces this
1463 // limit is elsewhere (class nmethod, class Method).
1464 //
1465 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1466 // to recompile at each bytecode independently of the per-BCI cutoff.
1467 //
1468 // The decision to update code is up to the compiler, and is encoded
1469 // in the Action_xxx code. If the compiler requests Action_none
1470 // no trap state is changed, no compiled code is changed, and the
1471 // computation suffers along in the interpreter.
1472 //
1473 // The other action codes specify various tactics for decompilation
1474 // and recompilation. Action_maybe_recompile is the loosest, and
1475 // allows the compiled code to stay around until enough traps are seen,
1476 // and until the compiler gets around to recompiling the trapping method.
1477 //
1478 // The other actions cause immediate removal of the present code.
1479
1480 bool update_trap_state = true;
1481 bool make_not_entrant = false;
1482 bool make_not_compilable = false;
1483 bool reprofile = false;
1484 switch (action) {
1485 case Action_none:
1486 // Keep the old code.
1487 update_trap_state = false;
1488 break;
1489 case Action_maybe_recompile:
1490 // Do not need to invalidate the present code, but we can
1491 // initiate another
1492 // Start compiler without (necessarily) invalidating the nmethod.
1493 // The system will tolerate the old code, but new code should be
1494 // generated when possible.
1495 break;
1496 case Action_reinterpret:
1497 // Go back into the interpreter for a while, and then consider
1498 // recompiling form scratch.
1499 make_not_entrant = true;
1500 // Reset invocation counter for outer most method.
1501 // This will allow the interpreter to exercise the bytecodes
1502 // for a while before recompiling.
1503 // By contrast, Action_make_not_entrant is immediate.
1504 //
1505 // Note that the compiler will track null_check, null_assert,
1506 // range_check, and class_check events and log them as if they
1507 // had been traps taken from compiled code. This will update
1508 // the MDO trap history so that the next compilation will
1509 // properly detect hot trap sites.
1510 reprofile = true;
1511 break;
1512 case Action_make_not_entrant:
1513 // Request immediate recompilation, and get rid of the old code.
1514 // Make them not entrant, so next time they are called they get
1515 // recompiled. Unloaded classes are loaded now so recompile before next
1516 // time they are called. Same for uninitialized. The interpreter will
1517 // link the missing class, if any.
1518 make_not_entrant = true;
1519 break;
1520 case Action_make_not_compilable:
1521 // Give up on compiling this method at all.
1522 make_not_entrant = true;
1523 make_not_compilable = true;
1524 break;
1525 default:
1526 ShouldNotReachHere();
1527 }
1528
1529 // Setting +ProfileTraps fixes the following, on all platforms:
1530 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1531 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1532 // recompile relies on a MethodData* to record heroic opt failures.
1533
1534 // Whether the interpreter is producing MDO data or not, we also need
1535 // to use the MDO to detect hot deoptimization points and control
1536 // aggressive optimization.
1537 bool inc_recompile_count = false;
1538 ProfileData* pdata = NULL;
1539 if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1540 assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1541 uint this_trap_count = 0;
1542 bool maybe_prior_trap = false;
1543 bool maybe_prior_recompile = false;
1544 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1545 nm->method(),
1546 //outputs:
1547 this_trap_count,
1548 maybe_prior_trap,
1549 maybe_prior_recompile);
1550 // Because the interpreter also counts null, div0, range, and class
1551 // checks, these traps from compiled code are double-counted.
1552 // This is harmless; it just means that the PerXTrapLimit values
1553 // are in effect a little smaller than they look.
1554
1555 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1556 if (per_bc_reason != Reason_none) {
1557 // Now take action based on the partially known per-BCI history.
1558 if (maybe_prior_trap
1559 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1560 // If there are too many traps at this BCI, force a recompile.
1561 // This will allow the compiler to see the limit overflow, and
1562 // take corrective action, if possible. The compiler generally
1563 // does not use the exact PerBytecodeTrapLimit value, but instead
1564 // changes its tactics if it sees any traps at all. This provides
1565 // a little hysteresis, delaying a recompile until a trap happens
1566 // several times.
1567 //
1568 // Actually, since there is only one bit of counter per BCI,
1569 // the possible per-BCI counts are {0,1,(per-method count)}.
1570 // This produces accurate results if in fact there is only
1571 // one hot trap site, but begins to get fuzzy if there are
1572 // many sites. For example, if there are ten sites each
1573 // trapping two or more times, they each get the blame for
1574 // all of their traps.
1575 make_not_entrant = true;
1576 }
1577
1578 // Detect repeated recompilation at the same BCI, and enforce a limit.
1579 if (make_not_entrant && maybe_prior_recompile) {
1580 // More than one recompile at this point.
1581 inc_recompile_count = maybe_prior_trap;
1582 }
1583 } else {
1584 // For reasons which are not recorded per-bytecode, we simply
1585 // force recompiles unconditionally.
1586 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1587 make_not_entrant = true;
1588 }
1589
1590 // Go back to the compiler if there are too many traps in this method.
1591 if (this_trap_count >= per_method_trap_limit(reason)) {
1592 // If there are too many traps in this method, force a recompile.
1593 // This will allow the compiler to see the limit overflow, and
1594 // take corrective action, if possible.
1595 // (This condition is an unlikely backstop only, because the
1596 // PerBytecodeTrapLimit is more likely to take effect first,
1597 // if it is applicable.)
1598 make_not_entrant = true;
1599 }
1600
1601 // Here's more hysteresis: If there has been a recompile at
1602 // this trap point already, run the method in the interpreter
1603 // for a while to exercise it more thoroughly.
1604 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1605 reprofile = true;
1606 }
1607
1608 }
1609
1610 // Take requested actions on the method:
1611
1612 // Recompile
1613 if (make_not_entrant) {
1614 if (!nm->make_not_entrant()) {
1615 return; // the call did not change nmethod's state
1616 }
1617
1618 if (pdata != NULL) {
1619 // Record the recompilation event, if any.
1620 int tstate0 = pdata->trap_state();
1621 int tstate1 = trap_state_set_recompiled(tstate0, true);
1622 if (tstate1 != tstate0)
1623 pdata->set_trap_state(tstate1);
1624 }
1625
1626 #if INCLUDE_RTM_OPT
1627 // Restart collecting RTM locking abort statistic if the method
1628 // is recompiled for a reason other than RTM state change.
1629 // Assume that in new recompiled code the statistic could be different,
1630 // for example, due to different inlining.
1631 if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1632 UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1633 trap_mdo->atomic_set_rtm_state(ProfileRTM);
1634 }
1635 #endif
1636 }
1637
1638 if (inc_recompile_count) {
1639 trap_mdo->inc_overflow_recompile_count();
1640 if ((uint)trap_mdo->overflow_recompile_count() >
1641 (uint)PerBytecodeRecompilationCutoff) {
1642 // Give up on the method containing the bad BCI.
1643 if (trap_method() == nm->method()) {
1644 make_not_compilable = true;
1645 } else {
1646 trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1647 // But give grace to the enclosing nm->method().
1648 }
1649 }
1650 }
1651
1652 // Reprofile
1653 if (reprofile) {
1654 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1655 }
1656
1657 // Give up compiling
1658 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1659 assert(make_not_entrant, "consistent");
1660 nm->method()->set_not_compilable(CompLevel_full_optimization);
1661 }
1662
1663 } // Free marked resources
1664
1665 }
1666 JRT_END
1667
1668 MethodData*
1669 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1670 bool create_if_missing) {
1671 Thread* THREAD = thread;
1672 MethodData* mdo = m()->method_data();
1673 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1674 // Build an MDO. Ignore errors like OutOfMemory;
1675 // that simply means we won't have an MDO to update.
1676 Method::build_interpreter_method_data(m, THREAD);
1677 if (HAS_PENDING_EXCEPTION) {
1678 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1679 CLEAR_PENDING_EXCEPTION;
1680 }
1681 mdo = m()->method_data();
1682 }
1683 return mdo;
1684 }
1685
1686 ProfileData*
1687 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1688 int trap_bci,
1689 Deoptimization::DeoptReason reason,
1690 Method* compiled_method,
1691 //outputs:
1692 uint& ret_this_trap_count,
1693 bool& ret_maybe_prior_trap,
1694 bool& ret_maybe_prior_recompile) {
1695 uint prior_trap_count = trap_mdo->trap_count(reason);
1696 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1697
1698 // If the runtime cannot find a place to store trap history,
1699 // it is estimated based on the general condition of the method.
1700 // If the method has ever been recompiled, or has ever incurred
1701 // a trap with the present reason , then this BCI is assumed
1702 // (pessimistically) to be the culprit.
1703 bool maybe_prior_trap = (prior_trap_count != 0);
1704 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1705 ProfileData* pdata = NULL;
1706
1707
1708 // For reasons which are recorded per bytecode, we check per-BCI data.
1709 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1710 if (per_bc_reason != Reason_none) {
1711 // Find the profile data for this BCI. If there isn't one,
1712 // try to allocate one from the MDO's set of spares.
1713 // This will let us detect a repeated trap at this point.
1714 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1715
1716 if (pdata != NULL) {
1717 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1718 if (LogCompilation && xtty != NULL) {
1719 ttyLocker ttyl;
1720 // no more room for speculative traps in this MDO
1721 xtty->elem("speculative_traps_oom");
1722 }
1723 }
1724 // Query the trap state of this profile datum.
1725 int tstate0 = pdata->trap_state();
1726 if (!trap_state_has_reason(tstate0, per_bc_reason))
1727 maybe_prior_trap = false;
1728 if (!trap_state_is_recompiled(tstate0))
1729 maybe_prior_recompile = false;
1730
1731 // Update the trap state of this profile datum.
1732 int tstate1 = tstate0;
1733 // Record the reason.
1734 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1735 // Store the updated state on the MDO, for next time.
1736 if (tstate1 != tstate0)
1737 pdata->set_trap_state(tstate1);
1738 } else {
1739 if (LogCompilation && xtty != NULL) {
1740 ttyLocker ttyl;
1741 // Missing MDP? Leave a small complaint in the log.
1742 xtty->elem("missing_mdp bci='%d'", trap_bci);
1743 }
1744 }
1745 }
1746
1747 // Return results:
1748 ret_this_trap_count = this_trap_count;
1749 ret_maybe_prior_trap = maybe_prior_trap;
1750 ret_maybe_prior_recompile = maybe_prior_recompile;
1751 return pdata;
1752 }
1753
1754 void
1755 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1756 ResourceMark rm;
1757 // Ignored outputs:
1758 uint ignore_this_trap_count;
1759 bool ignore_maybe_prior_trap;
1760 bool ignore_maybe_prior_recompile;
1761 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1762 query_update_method_data(trap_mdo, trap_bci,
1763 (DeoptReason)reason,
1764 NULL,
1765 ignore_this_trap_count,
1766 ignore_maybe_prior_trap,
1767 ignore_maybe_prior_recompile);
1768 }
1769
1770 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1771
1772 // Still in Java no safepoints
1773 {
1774 // This enters VM and may safepoint
1775 uncommon_trap_inner(thread, trap_request);
1776 }
1777 return fetch_unroll_info_helper(thread);
1778 }
1779
1780 // Local derived constants.
1781 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1782 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1783 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1784
1785 //---------------------------trap_state_reason---------------------------------
1786 Deoptimization::DeoptReason
1787 Deoptimization::trap_state_reason(int trap_state) {
1788 // This assert provides the link between the width of DataLayout::trap_bits
1789 // and the encoding of "recorded" reasons. It ensures there are enough
1790 // bits to store all needed reasons in the per-BCI MDO profile.
1791 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1792 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1793 trap_state -= recompile_bit;
1794 if (trap_state == DS_REASON_MASK) {
1795 return Reason_many;
1796 } else {
1797 assert((int)Reason_none == 0, "state=0 => Reason_none");
1798 return (DeoptReason)trap_state;
1799 }
1800 }
1801 //-------------------------trap_state_has_reason-------------------------------
1802 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1803 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1804 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1805 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1806 trap_state -= recompile_bit;
1807 if (trap_state == DS_REASON_MASK) {
1808 return -1; // true, unspecifically (bottom of state lattice)
1809 } else if (trap_state == reason) {
1810 return 1; // true, definitely
1811 } else if (trap_state == 0) {
1812 return 0; // false, definitely (top of state lattice)
1813 } else {
1814 return 0; // false, definitely
1815 }
1816 }
1817 //-------------------------trap_state_add_reason-------------------------------
1818 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1819 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1820 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1821 trap_state -= recompile_bit;
1822 if (trap_state == DS_REASON_MASK) {
1823 return trap_state + recompile_bit; // already at state lattice bottom
1824 } else if (trap_state == reason) {
1825 return trap_state + recompile_bit; // the condition is already true
1826 } else if (trap_state == 0) {
1827 return reason + recompile_bit; // no condition has yet been true
1828 } else {
1829 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1830 }
1831 }
1832 //-----------------------trap_state_is_recompiled------------------------------
1833 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1834 return (trap_state & DS_RECOMPILE_BIT) != 0;
1835 }
1836 //-----------------------trap_state_set_recompiled-----------------------------
1837 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1838 if (z) return trap_state | DS_RECOMPILE_BIT;
1839 else return trap_state & ~DS_RECOMPILE_BIT;
1840 }
1841 //---------------------------format_trap_state---------------------------------
1842 // This is used for debugging and diagnostics, including LogFile output.
1843 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1844 int trap_state) {
1845 DeoptReason reason = trap_state_reason(trap_state);
1846 bool recomp_flag = trap_state_is_recompiled(trap_state);
1847 // Re-encode the state from its decoded components.
1848 int decoded_state = 0;
1849 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1850 decoded_state = trap_state_add_reason(decoded_state, reason);
1851 if (recomp_flag)
1852 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1853 // If the state re-encodes properly, format it symbolically.
1854 // Because this routine is used for debugging and diagnostics,
1855 // be robust even if the state is a strange value.
1856 size_t len;
1857 if (decoded_state != trap_state) {
1858 // Random buggy state that doesn't decode??
1859 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1860 } else {
1861 len = jio_snprintf(buf, buflen, "%s%s",
1862 trap_reason_name(reason),
1863 recomp_flag ? " recompiled" : "");
1864 }
1865 if (len >= buflen)
1866 buf[buflen-1] = '\0';
1867 return buf;
1868 }
1869
1870
1871 //--------------------------------statics--------------------------------------
1872 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1873 = Deoptimization::Action_reinterpret;
1874 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1875 // Note: Keep this in sync. with enum DeoptReason.
1876 "none",
1877 "null_check",
1878 "null_assert",
1879 "range_check",
1880 "class_check",
1881 "array_check",
1882 "intrinsic",
1883 "bimorphic",
1884 "unloaded",
1885 "uninitialized",
1886 "unreached",
1887 "unhandled",
1888 "constraint",
1889 "div0_check",
1890 "age",
1891 "predicate",
1892 "loop_limit_check",
1893 "speculate_class_check",
1894 "rtm_state_change",
1895 "unstable_if"
1896 };
1897 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1898 // Note: Keep this in sync. with enum DeoptAction.
1899 "none",
1900 "maybe_recompile",
1901 "reinterpret",
1902 "make_not_entrant",
1903 "make_not_compilable"
1904 };
1905
1906 const char* Deoptimization::trap_reason_name(int reason) {
1907 if (reason == Reason_many) return "many";
1908 if ((uint)reason < Reason_LIMIT)
1909 return _trap_reason_name[reason];
1910 static char buf[20];
1911 sprintf(buf, "reason%d", reason);
1912 return buf;
1913 }
1914 const char* Deoptimization::trap_action_name(int action) {
1915 if ((uint)action < Action_LIMIT)
1916 return _trap_action_name[action];
1917 static char buf[20];
1918 sprintf(buf, "action%d", action);
1919 return buf;
1920 }
1921
1922 // This is used for debugging and diagnostics, including LogFile output.
1923 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1924 int trap_request) {
1925 jint unloaded_class_index = trap_request_index(trap_request);
1926 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1927 const char* action = trap_action_name(trap_request_action(trap_request));
1928 size_t len;
1929 if (unloaded_class_index < 0) {
1930 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1931 reason, action);
1932 } else {
1933 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1934 reason, action, unloaded_class_index);
1935 }
1936 if (len >= buflen)
1937 buf[buflen-1] = '\0';
1938 return buf;
1939 }
1940
1941 juint Deoptimization::_deoptimization_hist
1942 [Deoptimization::Reason_LIMIT]
1943 [1 + Deoptimization::Action_LIMIT]
1944 [Deoptimization::BC_CASE_LIMIT]
1945 = {0};
1946
1947 enum {
1948 LSB_BITS = 8,
1949 LSB_MASK = right_n_bits(LSB_BITS)
1950 };
1951
1952 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1953 Bytecodes::Code bc) {
1954 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1955 assert(action >= 0 && action < Action_LIMIT, "oob");
1956 _deoptimization_hist[Reason_none][0][0] += 1; // total
1957 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1958 juint* cases = _deoptimization_hist[reason][1+action];
1959 juint* bc_counter_addr = NULL;
1960 juint bc_counter = 0;
1961 // Look for an unused counter, or an exact match to this BC.
1962 if (bc != Bytecodes::_illegal) {
1963 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1964 juint* counter_addr = &cases[bc_case];
1965 juint counter = *counter_addr;
1966 if ((counter == 0 && bc_counter_addr == NULL)
1967 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1968 // this counter is either free or is already devoted to this BC
1969 bc_counter_addr = counter_addr;
1970 bc_counter = counter | bc;
1971 }
1972 }
1973 }
1974 if (bc_counter_addr == NULL) {
1975 // Overflow, or no given bytecode.
1976 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1977 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1978 }
1979 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1980 }
1981
1982 jint Deoptimization::total_deoptimization_count() {
1983 return _deoptimization_hist[Reason_none][0][0];
1984 }
1985
1986 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1987 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1988 return _deoptimization_hist[reason][0][0];
1989 }
1990
1991 void Deoptimization::print_statistics() {
1992 juint total = total_deoptimization_count();
1993 juint account = total;
1994 if (total != 0) {
1995 ttyLocker ttyl;
1996 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1997 tty->print_cr("Deoptimization traps recorded:");
1998 #define PRINT_STAT_LINE(name, r) \
1999 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2000 PRINT_STAT_LINE("total", total);
2001 // For each non-zero entry in the histogram, print the reason,
2002 // the action, and (if specifically known) the type of bytecode.
2003 for (int reason = 0; reason < Reason_LIMIT; reason++) {
2004 for (int action = 0; action < Action_LIMIT; action++) {
2005 juint* cases = _deoptimization_hist[reason][1+action];
2006 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2007 juint counter = cases[bc_case];
2008 if (counter != 0) {
2009 char name[1*K];
2010 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2011 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2012 bc = Bytecodes::_illegal;
2013 sprintf(name, "%s/%s/%s",
2014 trap_reason_name(reason),
2015 trap_action_name(action),
2016 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2017 juint r = counter >> LSB_BITS;
2018 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2019 account -= r;
2020 }
2021 }
2022 }
2023 }
2024 if (account != 0) {
2025 PRINT_STAT_LINE("unaccounted", account);
2026 }
2027 #undef PRINT_STAT_LINE
2028 if (xtty != NULL) xtty->tail("statistics");
2029 }
2030 }
2031 #else // COMPILER2 || SHARK
2032
2033
2034 // Stubs for C1 only system.
2035 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2036 return false;
2037 }
2038
2039 const char* Deoptimization::trap_reason_name(int reason) {
2040 return "unknown";
2041 }
2042
2043 void Deoptimization::print_statistics() {
2044 // no output
2045 }
2046
2047 void
2048 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2049 // no udpate
2050 }
2051
2052 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2053 return 0;
2054 }
2055
2056 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2057 Bytecodes::Code bc) {
2058 // no update
2059 }
2060
2061 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2062 int trap_state) {
2063 jio_snprintf(buf, buflen, "#%d", trap_state);
2064 return buf;
2065 }
2066
2067 #endif // COMPILER2 || SHARK