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