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