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