1 /*
2 * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/codeCache.hpp"
28 #include "code/debugInfoRec.hpp"
29 #include "code/nmethod.hpp"
30 #include "code/pcDesc.hpp"
31 #include "code/scopeDesc.hpp"
32 #include "interpreter/bytecode.hpp"
33 #include "interpreter/interpreter.hpp"
34 #include "interpreter/oopMapCache.hpp"
35 #include "memory/allocation.inline.hpp"
36 #include "memory/oopFactory.hpp"
37 #include "memory/resourceArea.hpp"
38 #include "oops/method.hpp"
39 #include "oops/oop.inline.hpp"
40 #include "prims/jvmtiThreadState.hpp"
41 #include "runtime/biasedLocking.hpp"
42 #include "runtime/compilationPolicy.hpp"
43 #include "runtime/deoptimization.hpp"
44 #include "runtime/interfaceSupport.hpp"
45 #include "runtime/sharedRuntime.hpp"
46 #include "runtime/signature.hpp"
47 #include "runtime/stubRoutines.hpp"
48 #include "runtime/thread.hpp"
49 #include "runtime/vframe.hpp"
50 #include "runtime/vframeArray.hpp"
51 #include "runtime/vframe_hp.hpp"
52 #include "utilities/events.hpp"
53 #include "utilities/xmlstream.hpp"
54
55 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
56
57 bool DeoptimizationMarker::_is_active = false;
58
59 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
60 int caller_adjustment,
61 int caller_actual_parameters,
62 int number_of_frames,
63 intptr_t* frame_sizes,
64 address* frame_pcs,
65 BasicType return_type) {
66 _size_of_deoptimized_frame = size_of_deoptimized_frame;
67 _caller_adjustment = caller_adjustment;
68 _caller_actual_parameters = caller_actual_parameters;
69 _number_of_frames = number_of_frames;
70 _frame_sizes = frame_sizes;
71 _frame_pcs = frame_pcs;
72 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
73 _return_type = return_type;
74 _initial_info = 0;
75 // PD (x86 only)
76 _counter_temp = 0;
77 _unpack_kind = 0;
78 _sender_sp_temp = 0;
79
80 _total_frame_sizes = size_of_frames();
81 }
82
83
84 Deoptimization::UnrollBlock::~UnrollBlock() {
85 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
86 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
87 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
88 }
89
90
91 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
92 assert(register_number < RegisterMap::reg_count, "checking register number");
93 return &_register_block[register_number * 2];
94 }
95
96
97
98 int Deoptimization::UnrollBlock::size_of_frames() const {
99 // Acount first for the adjustment of the initial frame
100 int result = _caller_adjustment;
101 for (int index = 0; index < number_of_frames(); index++) {
102 result += frame_sizes()[index];
103 }
104 return result;
105 }
106
107
108 void Deoptimization::UnrollBlock::print() {
109 ttyLocker ttyl;
110 tty->print_cr("UnrollBlock");
111 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
112 tty->print( " frame_sizes: ");
113 for (int index = 0; index < number_of_frames(); index++) {
114 tty->print("%d ", frame_sizes()[index]);
115 }
116 tty->cr();
117 }
118
119
120 // In order to make fetch_unroll_info work properly with escape
121 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
122 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
123 // of previously eliminated objects occurs in realloc_objects, which is
124 // called from the method fetch_unroll_info_helper below.
125 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
126 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
127 // but makes the entry a little slower. There is however a little dance we have to
128 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
129
130 // fetch_unroll_info() is called at the beginning of the deoptimization
131 // handler. Note this fact before we start generating temporary frames
132 // that can confuse an asynchronous stack walker. This counter is
133 // decremented at the end of unpack_frames().
134 thread->inc_in_deopt_handler();
135
136 return fetch_unroll_info_helper(thread);
137 JRT_END
138
139
140 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
141 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
142
143 // Note: there is a safepoint safety issue here. No matter whether we enter
144 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
145 // the vframeArray is created.
146 //
147
148 // Allocate our special deoptimization ResourceMark
149 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
150 assert(thread->deopt_mark() == NULL, "Pending deopt!");
151 thread->set_deopt_mark(dmark);
152
153 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
154 RegisterMap map(thread, true);
155 RegisterMap dummy_map(thread, false);
156 // Now get the deoptee with a valid map
157 frame deoptee = stub_frame.sender(&map);
158 // Set the deoptee nmethod
159 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
160 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
161
162 if (VerifyStack) {
163 thread->validate_frame_layout();
164 }
165
166 // Create a growable array of VFrames where each VFrame represents an inlined
167 // Java frame. This storage is allocated with the usual system arena.
168 assert(deoptee.is_compiled_frame(), "Wrong frame type");
169 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
170 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
171 while (!vf->is_top()) {
172 assert(vf->is_compiled_frame(), "Wrong frame type");
173 chunk->push(compiledVFrame::cast(vf));
174 vf = vf->sender();
175 }
176 assert(vf->is_compiled_frame(), "Wrong frame type");
177 chunk->push(compiledVFrame::cast(vf));
178
179 bool realloc_failures = false;
180
181 #ifdef COMPILER2
182 // Reallocate the non-escaping objects and restore their fields. Then
183 // relock objects if synchronization on them was eliminated.
184 if (DoEscapeAnalysis || EliminateNestedLocks) {
185 if (EliminateAllocations) {
186 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
187 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
188
189 // The flag return_oop() indicates call sites which return oop
190 // in compiled code. Such sites include java method calls,
191 // runtime calls (for example, used to allocate new objects/arrays
192 // on slow code path) and any other calls generated in compiled code.
193 // It is not guaranteed that we can get such information here only
194 // by analyzing bytecode in deoptimized frames. This is why this flag
195 // is set during method compilation (see Compile::Process_OopMap_Node()).
196 // If the previous frame was popped, we don't have a result.
197 bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution();
198 Handle return_value;
199 if (save_oop_result) {
200 // Reallocation may trigger GC. If deoptimization happened on return from
201 // call which returns oop we need to save it since it is not in oopmap.
202 oop result = deoptee.saved_oop_result(&map);
203 assert(result == NULL || result->is_oop(), "must be oop");
204 return_value = Handle(thread, result);
205 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
206 if (TraceDeoptimization) {
207 ttyLocker ttyl;
208 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
209 }
210 }
211 if (objects != NULL) {
212 JRT_BLOCK
213 realloc_failures = realloc_objects(thread, &deoptee, objects, THREAD);
214 JRT_END
215 reassign_fields(&deoptee, &map, objects, realloc_failures);
216 #ifndef PRODUCT
217 if (TraceDeoptimization) {
218 ttyLocker ttyl;
219 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
220 print_objects(objects, realloc_failures);
221 }
222 #endif
223 }
224 if (save_oop_result) {
225 // Restore result.
226 deoptee.set_saved_oop_result(&map, return_value());
227 }
228 }
229 if (EliminateLocks) {
230 #ifndef PRODUCT
231 bool first = true;
232 #endif
233 for (int i = 0; i < chunk->length(); i++) {
234 compiledVFrame* cvf = chunk->at(i);
235 assert (cvf->scope() != NULL,"expect only compiled java frames");
236 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
237 if (monitors->is_nonempty()) {
238 relock_objects(monitors, thread, realloc_failures);
239 #ifndef PRODUCT
240 if (TraceDeoptimization) {
241 ttyLocker ttyl;
242 for (int j = 0; j < monitors->length(); j++) {
243 MonitorInfo* mi = monitors->at(j);
244 if (mi->eliminated()) {
245 if (first) {
246 first = false;
247 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
248 }
249 if (mi->owner_is_scalar_replaced()) {
250 Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
251 tty->print_cr(" failed reallocation for klass %s", k->external_name());
252 } else {
253 tty->print_cr(" object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
254 }
255 }
256 }
257 }
258 #endif
259 }
260 }
261 }
262 }
263 #endif // COMPILER2
264 // Ensure that no safepoint is taken after pointers have been stored
265 // in fields of rematerialized objects. If a safepoint occurs from here on
266 // out the java state residing in the vframeArray will be missed.
267 No_Safepoint_Verifier no_safepoint;
268
269 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk, realloc_failures);
270 #ifdef COMPILER2
271 if (realloc_failures) {
272 pop_frames_failed_reallocs(thread, array);
273 }
274 #endif
275
276 assert(thread->vframe_array_head() == NULL, "Pending deopt!");
277 thread->set_vframe_array_head(array);
278
279 // Now that the vframeArray has been created if we have any deferred local writes
280 // added by jvmti then we can free up that structure as the data is now in the
281 // vframeArray
282
283 if (thread->deferred_locals() != NULL) {
284 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
285 int i = 0;
286 do {
287 // Because of inlining we could have multiple vframes for a single frame
288 // and several of the vframes could have deferred writes. Find them all.
289 if (list->at(i)->id() == array->original().id()) {
290 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
291 list->remove_at(i);
292 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
293 delete dlv;
294 } else {
295 i++;
296 }
297 } while ( i < list->length() );
298 if (list->length() == 0) {
299 thread->set_deferred_locals(NULL);
300 // free the list and elements back to C heap.
301 delete list;
302 }
303
304 }
305
306 #ifndef SHARK
307 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
308 CodeBlob* cb = stub_frame.cb();
309 // Verify we have the right vframeArray
310 assert(cb->frame_size() >= 0, "Unexpected frame size");
311 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
312
313 // If the deopt call site is a MethodHandle invoke call site we have
314 // to adjust the unpack_sp.
315 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
316 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
317 unpack_sp = deoptee.unextended_sp();
318
319 #ifdef ASSERT
320 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
321 #endif
322 #else
323 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
324 #endif // !SHARK
325
326 // This is a guarantee instead of an assert because if vframe doesn't match
327 // we will unpack the wrong deoptimized frame and wind up in strange places
328 // where it will be very difficult to figure out what went wrong. Better
329 // to die an early death here than some very obscure death later when the
330 // trail is cold.
331 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
332 // in that it will fail to detect a problem when there is one. This needs
333 // more work in tiger timeframe.
334 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
335
336 int number_of_frames = array->frames();
337
338 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
339 // virtual activation, which is the reverse of the elements in the vframes array.
340 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
341 // +1 because we always have an interpreter return address for the final slot.
342 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
343 int popframe_extra_args = 0;
344 // Create an interpreter return address for the stub to use as its return
345 // address so the skeletal frames are perfectly walkable
346 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
347
348 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
349 // activation be put back on the expression stack of the caller for reexecution
350 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
351 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
352 }
353
354 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
355 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
356 // than simply use array->sender.pc(). This requires us to walk the current set of frames
357 //
358 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
359 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
360
361 // It's possible that the number of parameters at the call site is
362 // different than number of arguments in the callee when method
363 // handles are used. If the caller is interpreted get the real
364 // value so that the proper amount of space can be added to it's
365 // frame.
366 bool caller_was_method_handle = false;
367 if (deopt_sender.is_interpreted_frame()) {
368 methodHandle method = deopt_sender.interpreter_frame_method();
369 Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
370 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
371 // Method handle invokes may involve fairly arbitrary chains of
372 // calls so it's impossible to know how much actual space the
373 // caller has for locals.
374 caller_was_method_handle = true;
375 }
376 }
377
378 //
379 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
380 // frame_sizes/frame_pcs[1] next oldest frame (int)
381 // frame_sizes/frame_pcs[n] youngest frame (int)
382 //
383 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
384 // owns the space for the return address to it's caller). Confusing ain't it.
385 //
386 // The vframe array can address vframes with indices running from
387 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
388 // When we create the skeletal frames we need the oldest frame to be in the zero slot
389 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
390 // so things look a little strange in this loop.
391 //
392 int callee_parameters = 0;
393 int callee_locals = 0;
394 for (int index = 0; index < array->frames(); index++ ) {
395 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
396 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
397 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
398 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
399 callee_locals,
400 index == 0,
401 popframe_extra_args);
402 // This pc doesn't have to be perfect just good enough to identify the frame
403 // as interpreted so the skeleton frame will be walkable
404 // The correct pc will be set when the skeleton frame is completely filled out
405 // The final pc we store in the loop is wrong and will be overwritten below
406 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
407
408 callee_parameters = array->element(index)->method()->size_of_parameters();
409 callee_locals = array->element(index)->method()->max_locals();
410 popframe_extra_args = 0;
411 }
412
413 // Compute whether the root vframe returns a float or double value.
414 BasicType return_type;
415 {
416 HandleMark hm;
417 methodHandle method(thread, array->element(0)->method());
418 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
419 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
420 }
421
422 // Compute information for handling adapters and adjusting the frame size of the caller.
423 int caller_adjustment = 0;
424
425 // Compute the amount the oldest interpreter frame will have to adjust
426 // its caller's stack by. If the caller is a compiled frame then
427 // we pretend that the callee has no parameters so that the
428 // extension counts for the full amount of locals and not just
429 // locals-parms. This is because without a c2i adapter the parm
430 // area as created by the compiled frame will not be usable by
431 // the interpreter. (Depending on the calling convention there
432 // may not even be enough space).
433
434 // QQQ I'd rather see this pushed down into last_frame_adjust
435 // and have it take the sender (aka caller).
436
437 if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
438 caller_adjustment = last_frame_adjust(0, callee_locals);
439 } else if (callee_locals > callee_parameters) {
440 // The caller frame may need extending to accommodate
441 // non-parameter locals of the first unpacked interpreted frame.
442 // Compute that adjustment.
443 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
444 }
445
446 // If the sender is deoptimized the we must retrieve the address of the handler
447 // since the frame will "magically" show the original pc before the deopt
448 // and we'd undo the deopt.
449
450 frame_pcs[0] = deopt_sender.raw_pc();
451
452 #ifndef SHARK
453 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
454 #endif // SHARK
455
456 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
457 caller_adjustment * BytesPerWord,
458 caller_was_method_handle ? 0 : callee_parameters,
459 number_of_frames,
460 frame_sizes,
461 frame_pcs,
462 return_type);
463 // On some platforms, we need a way to pass some platform dependent
464 // information to the unpacking code so the skeletal frames come out
465 // correct (initial fp value, unextended sp, ...)
466 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
467
468 if (array->frames() > 1) {
469 if (VerifyStack && TraceDeoptimization) {
470 ttyLocker ttyl;
471 tty->print_cr("Deoptimizing method containing inlining");
472 }
473 }
474
475 array->set_unroll_block(info);
476 return info;
477 }
478
479 // Called to cleanup deoptimization data structures in normal case
480 // after unpacking to stack and when stack overflow error occurs
481 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
482 vframeArray *array) {
483
484 // Get array if coming from exception
485 if (array == NULL) {
486 array = thread->vframe_array_head();
487 }
488 thread->set_vframe_array_head(NULL);
489
490 // Free the previous UnrollBlock
491 vframeArray* old_array = thread->vframe_array_last();
492 thread->set_vframe_array_last(array);
493
494 if (old_array != NULL) {
495 UnrollBlock* old_info = old_array->unroll_block();
496 old_array->set_unroll_block(NULL);
497 delete old_info;
498 delete old_array;
499 }
500
501 // Deallocate any resource creating in this routine and any ResourceObjs allocated
502 // inside the vframeArray (StackValueCollections)
503
504 delete thread->deopt_mark();
505 thread->set_deopt_mark(NULL);
506 thread->set_deopt_nmethod(NULL);
507
508
509 if (JvmtiExport::can_pop_frame()) {
510 #ifndef CC_INTERP
511 // Regardless of whether we entered this routine with the pending
512 // popframe condition bit set, we should always clear it now
513 thread->clear_popframe_condition();
514 #else
515 // C++ interpreter will clear has_pending_popframe when it enters
516 // with method_resume. For deopt_resume2 we clear it now.
517 if (thread->popframe_forcing_deopt_reexecution())
518 thread->clear_popframe_condition();
519 #endif /* CC_INTERP */
520 }
521
522 // unpack_frames() is called at the end of the deoptimization handler
523 // and (in C2) at the end of the uncommon trap handler. Note this fact
524 // so that an asynchronous stack walker can work again. This counter is
525 // incremented at the beginning of fetch_unroll_info() and (in C2) at
526 // the beginning of uncommon_trap().
527 thread->dec_in_deopt_handler();
528 }
529
530
531 // Return BasicType of value being returned
532 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
533
534 // We are already active int he special DeoptResourceMark any ResourceObj's we
535 // allocate will be freed at the end of the routine.
536
537 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
538 // but makes the entry a little slower. There is however a little dance we have to
539 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
540 ResetNoHandleMark rnhm; // No-op in release/product versions
541 HandleMark hm;
542
543 frame stub_frame = thread->last_frame();
544
545 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
546 // must point to the vframeArray for the unpack frame.
547 vframeArray* array = thread->vframe_array_head();
548
549 #ifndef PRODUCT
550 if (TraceDeoptimization) {
551 ttyLocker ttyl;
552 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
553 }
554 #endif
555 Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
556 stub_frame.pc(), stub_frame.sp(), exec_mode);
557
558 UnrollBlock* info = array->unroll_block();
559
560 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
561 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
562
563 BasicType bt = info->return_type();
564
565 // If we have an exception pending, claim that the return type is an oop
566 // so the deopt_blob does not overwrite the exception_oop.
567
568 if (exec_mode == Unpack_exception)
569 bt = T_OBJECT;
570
571 // Cleanup thread deopt data
572 cleanup_deopt_info(thread, array);
573
574 #ifndef PRODUCT
575 if (VerifyStack) {
576 ResourceMark res_mark;
577
578 thread->validate_frame_layout();
579
580 // Verify that the just-unpacked frames match the interpreter's
581 // notions of expression stack and locals
582 vframeArray* cur_array = thread->vframe_array_last();
583 RegisterMap rm(thread, false);
584 rm.set_include_argument_oops(false);
585 bool is_top_frame = true;
586 int callee_size_of_parameters = 0;
587 int callee_max_locals = 0;
588 for (int i = 0; i < cur_array->frames(); i++) {
589 vframeArrayElement* el = cur_array->element(i);
590 frame* iframe = el->iframe();
591 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
592
593 // Get the oop map for this bci
594 InterpreterOopMap mask;
595 int cur_invoke_parameter_size = 0;
596 bool try_next_mask = false;
597 int next_mask_expression_stack_size = -1;
598 int top_frame_expression_stack_adjustment = 0;
599 methodHandle mh(thread, iframe->interpreter_frame_method());
600 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
601 BytecodeStream str(mh);
602 str.set_start(iframe->interpreter_frame_bci());
603 int max_bci = mh->code_size();
604 // Get to the next bytecode if possible
605 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
606 // Check to see if we can grab the number of outgoing arguments
607 // at an uncommon trap for an invoke (where the compiler
608 // generates debug info before the invoke has executed)
609 Bytecodes::Code cur_code = str.next();
610 if (cur_code == Bytecodes::_invokevirtual ||
611 cur_code == Bytecodes::_invokespecial ||
612 cur_code == Bytecodes::_invokestatic ||
613 cur_code == Bytecodes::_invokeinterface ||
614 cur_code == Bytecodes::_invokedynamic) {
615 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
616 Symbol* signature = invoke.signature();
617 ArgumentSizeComputer asc(signature);
618 cur_invoke_parameter_size = asc.size();
619 if (invoke.has_receiver()) {
620 // Add in receiver
621 ++cur_invoke_parameter_size;
622 }
623 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
624 callee_size_of_parameters++;
625 }
626 }
627 if (str.bci() < max_bci) {
628 Bytecodes::Code bc = str.next();
629 if (bc >= 0) {
630 // The interpreter oop map generator reports results before
631 // the current bytecode has executed except in the case of
632 // calls. It seems to be hard to tell whether the compiler
633 // has emitted debug information matching the "state before"
634 // a given bytecode or the state after, so we try both
635 switch (cur_code) {
636 case Bytecodes::_invokevirtual:
637 case Bytecodes::_invokespecial:
638 case Bytecodes::_invokestatic:
639 case Bytecodes::_invokeinterface:
640 case Bytecodes::_invokedynamic:
641 case Bytecodes::_athrow:
642 break;
643 default: {
644 InterpreterOopMap next_mask;
645 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
646 next_mask_expression_stack_size = next_mask.expression_stack_size();
647 // Need to subtract off the size of the result type of
648 // the bytecode because this is not described in the
649 // debug info but returned to the interpreter in the TOS
650 // caching register
651 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
652 if (bytecode_result_type != T_ILLEGAL) {
653 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
654 }
655 assert(top_frame_expression_stack_adjustment >= 0, "");
656 try_next_mask = true;
657 break;
658 }
659 }
660 }
661 }
662
663 // Verify stack depth and oops in frame
664 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
665 if (!(
666 /* SPARC */
667 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
668 /* x86 */
669 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
670 (try_next_mask &&
671 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
672 top_frame_expression_stack_adjustment))) ||
673 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
674 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
675 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
676 )) {
677 ttyLocker ttyl;
678
679 // Print out some information that will help us debug the problem
680 tty->print_cr("Wrong number of expression stack elements during deoptimization");
681 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
682 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
683 iframe->interpreter_frame_expression_stack_size());
684 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
685 tty->print_cr(" try_next_mask = %d", try_next_mask);
686 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
687 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
688 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
689 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
690 tty->print_cr(" exec_mode = %d", exec_mode);
691 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
692 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
693 tty->print_cr(" Interpreted frames:");
694 for (int k = 0; k < cur_array->frames(); k++) {
695 vframeArrayElement* el = cur_array->element(k);
696 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
697 }
698 cur_array->print_on_2(tty);
699 guarantee(false, "wrong number of expression stack elements during deopt");
700 }
701 VerifyOopClosure verify;
702 iframe->oops_interpreted_do(&verify, NULL, &rm, false);
703 callee_size_of_parameters = mh->size_of_parameters();
704 callee_max_locals = mh->max_locals();
705 is_top_frame = false;
706 }
707 }
708 #endif /* !PRODUCT */
709
710
711 return bt;
712 JRT_END
713
714
715 int Deoptimization::deoptimize_dependents() {
716 Threads::deoptimized_wrt_marked_nmethods();
717 return 0;
718 }
719
720 Deoptimization::DeoptAction Deoptimization::_unloaded_action
721 = Deoptimization::Action_reinterpret;
722
723 #ifdef COMPILER2
724 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
725 Handle pending_exception(thread->pending_exception());
726 const char* exception_file = thread->exception_file();
727 int exception_line = thread->exception_line();
728 thread->clear_pending_exception();
729
730 bool failures = false;
731
732 for (int i = 0; i < objects->length(); i++) {
733 assert(objects->at(i)->is_object(), "invalid debug information");
734 ObjectValue* sv = (ObjectValue*) objects->at(i);
735
736 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
737 oop obj = NULL;
738
739 if (k->oop_is_instance()) {
740 InstanceKlass* ik = InstanceKlass::cast(k());
741 obj = ik->allocate_instance(THREAD);
742 } else if (k->oop_is_typeArray()) {
743 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
744 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
745 int len = sv->field_size() / type2size[ak->element_type()];
746 obj = ak->allocate(len, THREAD);
747 } else if (k->oop_is_objArray()) {
748 ObjArrayKlass* ak = ObjArrayKlass::cast(k());
749 obj = ak->allocate(sv->field_size(), THREAD);
750 }
751
752 if (obj == NULL) {
753 failures = true;
754 }
755
756 assert(sv->value().is_null(), "redundant reallocation");
757 assert(obj != NULL || HAS_PENDING_EXCEPTION, "allocation should succeed or we should get an exception");
758 CLEAR_PENDING_EXCEPTION;
759 sv->set_value(obj);
760 }
761
762 if (failures) {
763 THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
764 } else if (pending_exception.not_null()) {
765 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
766 }
767
768 return failures;
769 }
770
771 // This assumes that the fields are stored in ObjectValue in the same order
772 // they are yielded by do_nonstatic_fields.
773 class FieldReassigner: public FieldClosure {
774 frame* _fr;
775 RegisterMap* _reg_map;
776 ObjectValue* _sv;
777 InstanceKlass* _ik;
778 oop _obj;
779
780 int _i;
781 public:
782 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
783 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
784
785 int i() const { return _i; }
786
787
788 void do_field(fieldDescriptor* fd) {
789 intptr_t val;
790 StackValue* value =
791 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
792 int offset = fd->offset();
793 switch (fd->field_type()) {
794 case T_OBJECT: case T_ARRAY:
795 assert(value->type() == T_OBJECT, "Agreement.");
796 _obj->obj_field_put(offset, value->get_obj()());
797 break;
798
799 case T_LONG: case T_DOUBLE: {
800 assert(value->type() == T_INT, "Agreement.");
801 StackValue* low =
802 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
803 #ifdef _LP64
804 jlong res = (jlong)low->get_int();
805 #else
806 #ifdef SPARC
807 // For SPARC we have to swap high and low words.
808 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
809 #else
810 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
811 #endif //SPARC
812 #endif
813 _obj->long_field_put(offset, res);
814 break;
815 }
816 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
817 case T_INT: case T_FLOAT: // 4 bytes.
818 assert(value->type() == T_INT, "Agreement.");
819 val = value->get_int();
820 _obj->int_field_put(offset, (jint)*((jint*)&val));
821 break;
822
823 case T_SHORT: case T_CHAR: // 2 bytes
824 assert(value->type() == T_INT, "Agreement.");
825 val = value->get_int();
826 _obj->short_field_put(offset, (jshort)*((jint*)&val));
827 break;
828
829 case T_BOOLEAN: case T_BYTE: // 1 byte
830 assert(value->type() == T_INT, "Agreement.");
831 val = value->get_int();
832 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
833 break;
834
835 default:
836 ShouldNotReachHere();
837 }
838 _i++;
839 }
840 };
841
842 // restore elements of an eliminated type array
843 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
844 int index = 0;
845 intptr_t val;
846
847 for (int i = 0; i < sv->field_size(); i++) {
848 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
849 switch(type) {
850 case T_LONG: case T_DOUBLE: {
851 assert(value->type() == T_INT, "Agreement.");
852 StackValue* low =
853 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
854 #ifdef _LP64
855 jlong res = (jlong)low->get_int();
856 #else
857 #ifdef SPARC
858 // For SPARC we have to swap high and low words.
859 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
860 #else
861 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
862 #endif //SPARC
863 #endif
864 obj->long_at_put(index, res);
865 break;
866 }
867
868 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
869 case T_INT: case T_FLOAT: // 4 bytes.
870 assert(value->type() == T_INT, "Agreement.");
871 val = value->get_int();
872 obj->int_at_put(index, (jint)*((jint*)&val));
873 break;
874
875 case T_SHORT: case T_CHAR: // 2 bytes
876 assert(value->type() == T_INT, "Agreement.");
877 val = value->get_int();
878 obj->short_at_put(index, (jshort)*((jint*)&val));
879 break;
880
881 case T_BOOLEAN: case T_BYTE: // 1 byte
882 assert(value->type() == T_INT, "Agreement.");
883 val = value->get_int();
884 obj->bool_at_put(index, (jboolean)*((jint*)&val));
885 break;
886
887 default:
888 ShouldNotReachHere();
889 }
890 index++;
891 }
892 }
893
894
895 // restore fields of an eliminated object array
896 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
897 for (int i = 0; i < sv->field_size(); i++) {
898 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
899 assert(value->type() == T_OBJECT, "object element expected");
900 obj->obj_at_put(i, value->get_obj()());
901 }
902 }
903
904
905 // restore fields of all eliminated objects and arrays
906 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
907 for (int i = 0; i < objects->length(); i++) {
908 ObjectValue* sv = (ObjectValue*) objects->at(i);
909 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
910 Handle obj = sv->value();
911 assert(obj.not_null() || realloc_failures, "reallocation was missed");
912 if (obj.is_null()) {
913 continue;
914 }
915
916 if (k->oop_is_instance()) {
917 InstanceKlass* ik = InstanceKlass::cast(k());
918 FieldReassigner reassign(fr, reg_map, sv, obj());
919 ik->do_nonstatic_fields(&reassign);
920 } else if (k->oop_is_typeArray()) {
921 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
922 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
923 } else if (k->oop_is_objArray()) {
924 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
925 }
926 }
927 }
928
929
930 // relock objects for which synchronization was eliminated
931 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures) {
932 for (int i = 0; i < monitors->length(); i++) {
933 MonitorInfo* mon_info = monitors->at(i);
934 if (mon_info->eliminated()) {
935 assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
936 if (!mon_info->owner_is_scalar_replaced()) {
937 Handle obj = Handle(mon_info->owner());
938 markOop mark = obj->mark();
939 if (UseBiasedLocking && mark->has_bias_pattern()) {
940 // New allocated objects may have the mark set to anonymously biased.
941 // Also the deoptimized method may called methods with synchronization
942 // where the thread-local object is bias locked to the current thread.
943 assert(mark->is_biased_anonymously() ||
944 mark->biased_locker() == thread, "should be locked to current thread");
945 // Reset mark word to unbiased prototype.
946 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
947 obj->set_mark(unbiased_prototype);
948 }
949 BasicLock* lock = mon_info->lock();
950 ObjectSynchronizer::slow_enter(obj, lock, thread);
951 assert(mon_info->owner()->is_locked(), "object must be locked now");
952 }
953 }
954 }
955 }
956
957
958 #ifndef PRODUCT
959 // print information about reallocated objects
960 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
961 fieldDescriptor fd;
962
963 for (int i = 0; i < objects->length(); i++) {
964 ObjectValue* sv = (ObjectValue*) objects->at(i);
965 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
966 Handle obj = sv->value();
967
968 tty->print(" object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
969 k->print_value();
970 assert(obj.not_null() || realloc_failures, "reallocation was missed");
971 if (obj.is_null()) {
972 tty->print(" allocation failed");
973 } else {
974 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
975 }
976 tty->cr();
977
978 if (Verbose && !obj.is_null()) {
979 k->oop_print_on(obj(), tty);
980 }
981 }
982 }
983 #endif
984 #endif // COMPILER2
985
986 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
987 Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
988
989 #ifndef PRODUCT
990 if (TraceDeoptimization) {
991 ttyLocker ttyl;
992 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
993 fr.print_on(tty);
994 tty->print_cr(" Virtual frames (innermost first):");
995 for (int index = 0; index < chunk->length(); index++) {
996 compiledVFrame* vf = chunk->at(index);
997 tty->print(" %2d - ", index);
998 vf->print_value();
999 int bci = chunk->at(index)->raw_bci();
1000 const char* code_name;
1001 if (bci == SynchronizationEntryBCI) {
1002 code_name = "sync entry";
1003 } else {
1004 Bytecodes::Code code = vf->method()->code_at(bci);
1005 code_name = Bytecodes::name(code);
1006 }
1007 tty->print(" - %s", code_name);
1008 tty->print_cr(" @ bci %d ", bci);
1009 if (Verbose) {
1010 vf->print();
1011 tty->cr();
1012 }
1013 }
1014 }
1015 #endif
1016
1017 // Register map for next frame (used for stack crawl). We capture
1018 // the state of the deopt'ing frame's caller. Thus if we need to
1019 // stuff a C2I adapter we can properly fill in the callee-save
1020 // register locations.
1021 frame caller = fr.sender(reg_map);
1022 int frame_size = caller.sp() - fr.sp();
1023
1024 frame sender = caller;
1025
1026 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1027 // the vframeArray containing the unpacking information is allocated in the C heap.
1028 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1029 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1030
1031 // Compare the vframeArray to the collected vframes
1032 assert(array->structural_compare(thread, chunk), "just checking");
1033
1034 #ifndef PRODUCT
1035 if (TraceDeoptimization) {
1036 ttyLocker ttyl;
1037 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1038 }
1039 #endif // PRODUCT
1040
1041 return array;
1042 }
1043
1044 #ifdef COMPILER2
1045 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1046 // Reallocation of some scalar replaced objects failed. Record
1047 // that we need to pop all the interpreter frames for the
1048 // deoptimized compiled frame.
1049 assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1050 thread->set_frames_to_pop_failed_realloc(array->frames());
1051 // Unlock all monitors here otherwise the interpreter will see a
1052 // mix of locked and unlocked monitors (because of failed
1053 // reallocations of synchronized objects) and be confused.
1054 for (int i = 0; i < array->frames(); i++) {
1055 MonitorChunk* monitors = array->element(i)->monitors();
1056 if (monitors != NULL) {
1057 for (int j = 0; j < monitors->number_of_monitors(); j++) {
1058 BasicObjectLock* src = monitors->at(j);
1059 if (src->obj() != NULL) {
1060 ObjectSynchronizer::fast_exit(src->obj(), src->lock(), thread);
1061 }
1062 }
1063 array->element(i)->free_monitors(thread);
1064 #ifdef ASSERT
1065 array->element(i)->set_removed_monitors();
1066 #endif
1067 }
1068 }
1069 }
1070 #endif
1071
1072 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1073 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1074 for (int i = 0; i < monitors->length(); i++) {
1075 MonitorInfo* mon_info = monitors->at(i);
1076 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1077 objects_to_revoke->append(Handle(mon_info->owner()));
1078 }
1079 }
1080 }
1081
1082
1083 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1084 if (!UseBiasedLocking) {
1085 return;
1086 }
1087
1088 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1089
1090 // Unfortunately we don't have a RegisterMap available in most of
1091 // the places we want to call this routine so we need to walk the
1092 // stack again to update the register map.
1093 if (map == NULL || !map->update_map()) {
1094 StackFrameStream sfs(thread, true);
1095 bool found = false;
1096 while (!found && !sfs.is_done()) {
1097 frame* cur = sfs.current();
1098 sfs.next();
1099 found = cur->id() == fr.id();
1100 }
1101 assert(found, "frame to be deoptimized not found on target thread's stack");
1102 map = sfs.register_map();
1103 }
1104
1105 vframe* vf = vframe::new_vframe(&fr, map, thread);
1106 compiledVFrame* cvf = compiledVFrame::cast(vf);
1107 // Revoke monitors' biases in all scopes
1108 while (!cvf->is_top()) {
1109 collect_monitors(cvf, objects_to_revoke);
1110 cvf = compiledVFrame::cast(cvf->sender());
1111 }
1112 collect_monitors(cvf, objects_to_revoke);
1113
1114 if (SafepointSynchronize::is_at_safepoint()) {
1115 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1116 } else {
1117 BiasedLocking::revoke(objects_to_revoke);
1118 }
1119 }
1120
1121
1122 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1123 if (!UseBiasedLocking) {
1124 return;
1125 }
1126
1127 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1128 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1129 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1130 if (jt->has_last_Java_frame()) {
1131 StackFrameStream sfs(jt, true);
1132 while (!sfs.is_done()) {
1133 frame* cur = sfs.current();
1134 if (cb->contains(cur->pc())) {
1135 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1136 compiledVFrame* cvf = compiledVFrame::cast(vf);
1137 // Revoke monitors' biases in all scopes
1138 while (!cvf->is_top()) {
1139 collect_monitors(cvf, objects_to_revoke);
1140 cvf = compiledVFrame::cast(cvf->sender());
1141 }
1142 collect_monitors(cvf, objects_to_revoke);
1143 }
1144 sfs.next();
1145 }
1146 }
1147 }
1148 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1149 }
1150
1151
1152 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1153 assert(fr.can_be_deoptimized(), "checking frame type");
1154
1155 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1156
1157 // Patch the nmethod so that when execution returns to it we will
1158 // deopt the execution state and return to the interpreter.
1159 fr.deoptimize(thread);
1160 }
1161
1162 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1163 // Deoptimize only if the frame comes from compile code.
1164 // Do not deoptimize the frame which is already patched
1165 // during the execution of the loops below.
1166 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1167 return;
1168 }
1169 ResourceMark rm;
1170 DeoptimizationMarker dm;
1171 if (UseBiasedLocking) {
1172 revoke_biases_of_monitors(thread, fr, map);
1173 }
1174 deoptimize_single_frame(thread, fr);
1175
1176 }
1177
1178
1179 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1180 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1181 "can only deoptimize other thread at a safepoint");
1182 // Compute frame and register map based on thread and sp.
1183 RegisterMap reg_map(thread, UseBiasedLocking);
1184 frame fr = thread->last_frame();
1185 while (fr.id() != id) {
1186 fr = fr.sender(®_map);
1187 }
1188 deoptimize(thread, fr, ®_map);
1189 }
1190
1191
1192 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1193 if (thread == Thread::current()) {
1194 Deoptimization::deoptimize_frame_internal(thread, id);
1195 } else {
1196 VM_DeoptimizeFrame deopt(thread, id);
1197 VMThread::execute(&deopt);
1198 }
1199 }
1200
1201
1202 // JVMTI PopFrame support
1203 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1204 {
1205 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1206 }
1207 JRT_END
1208
1209 MethodData*
1210 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1211 bool create_if_missing) {
1212 Thread* THREAD = thread;
1213 MethodData* mdo = m()->method_data();
1214 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1215 // Build an MDO. Ignore errors like OutOfMemory;
1216 // that simply means we won't have an MDO to update.
1217 Method::build_interpreter_method_data(m, THREAD);
1218 if (HAS_PENDING_EXCEPTION) {
1219 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1220 CLEAR_PENDING_EXCEPTION;
1221 }
1222 mdo = m()->method_data();
1223 }
1224 return mdo;
1225 }
1226
1227 #if defined(COMPILER2) || defined(SHARK)
1228 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1229 // in case of an unresolved klass entry, load the class.
1230 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1231 Klass* tk = constant_pool->klass_at_ignore_error(index, CHECK);
1232 return;
1233 }
1234
1235 if (!constant_pool->tag_at(index).is_symbol()) return;
1236
1237 Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1238 Symbol* symbol = constant_pool->symbol_at(index);
1239
1240 // class name?
1241 if (symbol->byte_at(0) != '(') {
1242 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1243 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1244 return;
1245 }
1246
1247 // then it must be a signature!
1248 ResourceMark rm(THREAD);
1249 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1250 if (ss.is_object()) {
1251 Symbol* class_name = ss.as_symbol(CHECK);
1252 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1253 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1254 }
1255 }
1256 }
1257
1258
1259 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1260 EXCEPTION_MARK;
1261 load_class_by_index(constant_pool, index, THREAD);
1262 if (HAS_PENDING_EXCEPTION) {
1263 // Exception happened during classloading. We ignore the exception here, since it
1264 // is going to be rethrown since the current activation is going to be deoptimized and
1265 // the interpreter will re-execute the bytecode.
1266 CLEAR_PENDING_EXCEPTION;
1267 // Class loading called java code which may have caused a stack
1268 // overflow. If the exception was thrown right before the return
1269 // to the runtime the stack is no longer guarded. Reguard the
1270 // stack otherwise if we return to the uncommon trap blob and the
1271 // stack bang causes a stack overflow we crash.
1272 assert(THREAD->is_Java_thread(), "only a java thread can be here");
1273 JavaThread* thread = (JavaThread*)THREAD;
1274 bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1275 if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1276 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1277 }
1278 }
1279
1280 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1281 HandleMark hm;
1282
1283 // uncommon_trap() is called at the beginning of the uncommon trap
1284 // handler. Note this fact before we start generating temporary frames
1285 // that can confuse an asynchronous stack walker. This counter is
1286 // decremented at the end of unpack_frames().
1287 thread->inc_in_deopt_handler();
1288
1289 // We need to update the map if we have biased locking.
1290 RegisterMap reg_map(thread, UseBiasedLocking);
1291 frame stub_frame = thread->last_frame();
1292 frame fr = stub_frame.sender(®_map);
1293 // Make sure the calling nmethod is not getting deoptimized and removed
1294 // before we are done with it.
1295 nmethodLocker nl(fr.pc());
1296
1297 // Log a message
1298 Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1299 trap_request, fr.pc());
1300
1301 {
1302 ResourceMark rm;
1303
1304 // Revoke biases of any monitors in the frame to ensure we can migrate them
1305 revoke_biases_of_monitors(thread, fr, ®_map);
1306
1307 DeoptReason reason = trap_request_reason(trap_request);
1308 DeoptAction action = trap_request_action(trap_request);
1309 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1310
1311 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1312 compiledVFrame* cvf = compiledVFrame::cast(vf);
1313
1314 nmethod* nm = cvf->code();
1315
1316 ScopeDesc* trap_scope = cvf->scope();
1317 methodHandle trap_method = trap_scope->method();
1318 int trap_bci = trap_scope->bci();
1319 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1320
1321 // Record this event in the histogram.
1322 gather_statistics(reason, action, trap_bc);
1323
1324 // Ensure that we can record deopt. history:
1325 // Need MDO to record RTM code generation state.
1326 bool create_if_missing = ProfileTraps || UseCodeAging RTM_OPT_ONLY( || UseRTMLocking );
1327
1328 MethodData* trap_mdo =
1329 get_method_data(thread, trap_method, create_if_missing);
1330
1331 // Log a message
1332 Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1333 trap_reason_name(reason), trap_action_name(action), fr.pc(),
1334 trap_method->name_and_sig_as_C_string(), trap_bci);
1335
1336 // Print a bunch of diagnostics, if requested.
1337 if (TraceDeoptimization || LogCompilation) {
1338 ResourceMark rm;
1339 ttyLocker ttyl;
1340 char buf[100];
1341 if (xtty != NULL) {
1342 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1343 os::current_thread_id(),
1344 format_trap_request(buf, sizeof(buf), trap_request));
1345 nm->log_identity(xtty);
1346 }
1347 Symbol* class_name = NULL;
1348 bool unresolved = false;
1349 if (unloaded_class_index >= 0) {
1350 constantPoolHandle constants (THREAD, trap_method->constants());
1351 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1352 class_name = constants->klass_name_at(unloaded_class_index);
1353 unresolved = true;
1354 if (xtty != NULL)
1355 xtty->print(" unresolved='1'");
1356 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1357 class_name = constants->symbol_at(unloaded_class_index);
1358 }
1359 if (xtty != NULL)
1360 xtty->name(class_name);
1361 }
1362 if (xtty != NULL && trap_mdo != NULL && (int)reason < (int)MethodData::_trap_hist_limit) {
1363 // Dump the relevant MDO state.
1364 // This is the deopt count for the current reason, any previous
1365 // reasons or recompiles seen at this point.
1366 int dcnt = trap_mdo->trap_count(reason);
1367 if (dcnt != 0)
1368 xtty->print(" count='%d'", dcnt);
1369 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1370 int dos = (pdata == NULL)? 0: pdata->trap_state();
1371 if (dos != 0) {
1372 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1373 if (trap_state_is_recompiled(dos)) {
1374 int recnt2 = trap_mdo->overflow_recompile_count();
1375 if (recnt2 != 0)
1376 xtty->print(" recompiles2='%d'", recnt2);
1377 }
1378 }
1379 }
1380 if (xtty != NULL) {
1381 xtty->stamp();
1382 xtty->end_head();
1383 }
1384 if (TraceDeoptimization) { // make noise on the tty
1385 tty->print("Uncommon trap occurred in");
1386 nm->method()->print_short_name(tty);
1387 tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1388 fr.pc(),
1389 os::current_thread_id(),
1390 trap_reason_name(reason),
1391 trap_action_name(action),
1392 unloaded_class_index);
1393 if (class_name != NULL) {
1394 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1395 class_name->print_symbol_on(tty);
1396 }
1397 tty->cr();
1398 }
1399 if (xtty != NULL) {
1400 // Log the precise location of the trap.
1401 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1402 xtty->begin_elem("jvms bci='%d'", sd->bci());
1403 xtty->method(sd->method());
1404 xtty->end_elem();
1405 if (sd->is_top()) break;
1406 }
1407 xtty->tail("uncommon_trap");
1408 }
1409 }
1410 // (End diagnostic printout.)
1411
1412 // Load class if necessary
1413 if (unloaded_class_index >= 0) {
1414 constantPoolHandle constants(THREAD, trap_method->constants());
1415 load_class_by_index(constants, unloaded_class_index);
1416 }
1417
1418 // Flush the nmethod if necessary and desirable.
1419 //
1420 // We need to avoid situations where we are re-flushing the nmethod
1421 // because of a hot deoptimization site. Repeated flushes at the same
1422 // point need to be detected by the compiler and avoided. If the compiler
1423 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1424 // module must take measures to avoid an infinite cycle of recompilation
1425 // and deoptimization. There are several such measures:
1426 //
1427 // 1. If a recompilation is ordered a second time at some site X
1428 // and for the same reason R, the action is adjusted to 'reinterpret',
1429 // to give the interpreter time to exercise the method more thoroughly.
1430 // If this happens, the method's overflow_recompile_count is incremented.
1431 //
1432 // 2. If the compiler fails to reduce the deoptimization rate, then
1433 // the method's overflow_recompile_count will begin to exceed the set
1434 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1435 // is adjusted to 'make_not_compilable', and the method is abandoned
1436 // to the interpreter. This is a performance hit for hot methods,
1437 // but is better than a disastrous infinite cycle of recompilations.
1438 // (Actually, only the method containing the site X is abandoned.)
1439 //
1440 // 3. In parallel with the previous measures, if the total number of
1441 // recompilations of a method exceeds the much larger set limit
1442 // PerMethodRecompilationCutoff, the method is abandoned.
1443 // This should only happen if the method is very large and has
1444 // many "lukewarm" deoptimizations. The code which enforces this
1445 // limit is elsewhere (class nmethod, class Method).
1446 //
1447 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1448 // to recompile at each bytecode independently of the per-BCI cutoff.
1449 //
1450 // The decision to update code is up to the compiler, and is encoded
1451 // in the Action_xxx code. If the compiler requests Action_none
1452 // no trap state is changed, no compiled code is changed, and the
1453 // computation suffers along in the interpreter.
1454 //
1455 // The other action codes specify various tactics for decompilation
1456 // and recompilation. Action_maybe_recompile is the loosest, and
1457 // allows the compiled code to stay around until enough traps are seen,
1458 // and until the compiler gets around to recompiling the trapping method.
1459 //
1460 // The other actions cause immediate removal of the present code.
1461
1462 bool update_trap_state = (reason != Reason_tenured);
1463 bool make_not_entrant = false;
1464 bool make_not_compilable = false;
1465 bool reprofile = false;
1466 switch (action) {
1467 case Action_none:
1468 // Keep the old code.
1469 update_trap_state = false;
1470 break;
1471 case Action_maybe_recompile:
1472 // Do not need to invalidate the present code, but we can
1473 // initiate another
1474 // Start compiler without (necessarily) invalidating the nmethod.
1475 // The system will tolerate the old code, but new code should be
1476 // generated when possible.
1477 break;
1478 case Action_reinterpret:
1479 // Go back into the interpreter for a while, and then consider
1480 // recompiling form scratch.
1481 make_not_entrant = true;
1482 // Reset invocation counter for outer most method.
1483 // This will allow the interpreter to exercise the bytecodes
1484 // for a while before recompiling.
1485 // By contrast, Action_make_not_entrant is immediate.
1486 //
1487 // Note that the compiler will track null_check, null_assert,
1488 // range_check, and class_check events and log them as if they
1489 // had been traps taken from compiled code. This will update
1490 // the MDO trap history so that the next compilation will
1491 // properly detect hot trap sites.
1492 reprofile = true;
1493 break;
1494 case Action_make_not_entrant:
1495 // Request immediate recompilation, and get rid of the old code.
1496 // Make them not entrant, so next time they are called they get
1497 // recompiled. Unloaded classes are loaded now so recompile before next
1498 // time they are called. Same for uninitialized. The interpreter will
1499 // link the missing class, if any.
1500 make_not_entrant = true;
1501 break;
1502 case Action_make_not_compilable:
1503 // Give up on compiling this method at all.
1504 make_not_entrant = true;
1505 make_not_compilable = true;
1506 break;
1507 default:
1508 ShouldNotReachHere();
1509 }
1510
1511 // Setting +ProfileTraps fixes the following, on all platforms:
1512 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1513 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1514 // recompile relies on a MethodData* to record heroic opt failures.
1515
1516 // Whether the interpreter is producing MDO data or not, we also need
1517 // to use the MDO to detect hot deoptimization points and control
1518 // aggressive optimization.
1519 bool inc_recompile_count = false;
1520 ProfileData* pdata = NULL;
1521 if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1522 assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1523 uint this_trap_count = 0;
1524 bool maybe_prior_trap = false;
1525 bool maybe_prior_recompile = false;
1526 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1527 nm->method(),
1528 //outputs:
1529 this_trap_count,
1530 maybe_prior_trap,
1531 maybe_prior_recompile);
1532 // Because the interpreter also counts null, div0, range, and class
1533 // checks, these traps from compiled code are double-counted.
1534 // This is harmless; it just means that the PerXTrapLimit values
1535 // are in effect a little smaller than they look.
1536
1537 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1538 if (per_bc_reason != Reason_none) {
1539 // Now take action based on the partially known per-BCI history.
1540 if (maybe_prior_trap
1541 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1542 // If there are too many traps at this BCI, force a recompile.
1543 // This will allow the compiler to see the limit overflow, and
1544 // take corrective action, if possible. The compiler generally
1545 // does not use the exact PerBytecodeTrapLimit value, but instead
1546 // changes its tactics if it sees any traps at all. This provides
1547 // a little hysteresis, delaying a recompile until a trap happens
1548 // several times.
1549 //
1550 // Actually, since there is only one bit of counter per BCI,
1551 // the possible per-BCI counts are {0,1,(per-method count)}.
1552 // This produces accurate results if in fact there is only
1553 // one hot trap site, but begins to get fuzzy if there are
1554 // many sites. For example, if there are ten sites each
1555 // trapping two or more times, they each get the blame for
1556 // all of their traps.
1557 make_not_entrant = true;
1558 }
1559
1560 // Detect repeated recompilation at the same BCI, and enforce a limit.
1561 if (make_not_entrant && maybe_prior_recompile) {
1562 // More than one recompile at this point.
1563 inc_recompile_count = maybe_prior_trap;
1564 }
1565 } else {
1566 // For reasons which are not recorded per-bytecode, we simply
1567 // force recompiles unconditionally.
1568 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1569 make_not_entrant = true;
1570 }
1571
1572 // Go back to the compiler if there are too many traps in this method.
1573 if (this_trap_count >= per_method_trap_limit(reason)) {
1574 // If there are too many traps in this method, force a recompile.
1575 // This will allow the compiler to see the limit overflow, and
1576 // take corrective action, if possible.
1577 // (This condition is an unlikely backstop only, because the
1578 // PerBytecodeTrapLimit is more likely to take effect first,
1579 // if it is applicable.)
1580 make_not_entrant = true;
1581 }
1582
1583 // Here's more hysteresis: If there has been a recompile at
1584 // this trap point already, run the method in the interpreter
1585 // for a while to exercise it more thoroughly.
1586 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1587 reprofile = true;
1588 }
1589 }
1590
1591 // Take requested actions on the method:
1592
1593 // Recompile
1594 if (make_not_entrant) {
1595 if (!nm->make_not_entrant()) {
1596 return; // the call did not change nmethod's state
1597 }
1598
1599 if (pdata != NULL) {
1600 // Record the recompilation event, if any.
1601 int tstate0 = pdata->trap_state();
1602 int tstate1 = trap_state_set_recompiled(tstate0, true);
1603 if (tstate1 != tstate0)
1604 pdata->set_trap_state(tstate1);
1605 }
1606
1607 #if INCLUDE_RTM_OPT
1608 // Restart collecting RTM locking abort statistic if the method
1609 // is recompiled for a reason other than RTM state change.
1610 // Assume that in new recompiled code the statistic could be different,
1611 // for example, due to different inlining.
1612 if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1613 UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1614 trap_mdo->atomic_set_rtm_state(ProfileRTM);
1615 }
1616 #endif
1617 // For code aging we count traps separately here, using make_not_entrant()
1618 // as a guard against simultaneous deopts in multiple threads.
1619 if (reason == Reason_tenured && trap_mdo != NULL) {
1620 trap_mdo->inc_tenure_traps();
1621 }
1622 }
1623
1624 if (inc_recompile_count) {
1625 trap_mdo->inc_overflow_recompile_count();
1626 if ((uint)trap_mdo->overflow_recompile_count() >
1627 (uint)PerBytecodeRecompilationCutoff) {
1628 // Give up on the method containing the bad BCI.
1629 if (trap_method() == nm->method()) {
1630 make_not_compilable = true;
1631 } else {
1632 trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1633 // But give grace to the enclosing nm->method().
1634 }
1635 }
1636 }
1637
1638 // Reprofile
1639 if (reprofile) {
1640 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1641 }
1642
1643 // Give up compiling
1644 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1645 assert(make_not_entrant, "consistent");
1646 nm->method()->set_not_compilable(CompLevel_full_optimization);
1647 }
1648
1649 } // Free marked resources
1650
1651 }
1652 JRT_END
1653
1654 ProfileData*
1655 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1656 int trap_bci,
1657 Deoptimization::DeoptReason reason,
1658 Method* compiled_method,
1659 //outputs:
1660 uint& ret_this_trap_count,
1661 bool& ret_maybe_prior_trap,
1662 bool& ret_maybe_prior_recompile) {
1663 uint prior_trap_count = trap_mdo->trap_count(reason);
1664 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1665
1666 // If the runtime cannot find a place to store trap history,
1667 // it is estimated based on the general condition of the method.
1668 // If the method has ever been recompiled, or has ever incurred
1669 // a trap with the present reason , then this BCI is assumed
1670 // (pessimistically) to be the culprit.
1671 bool maybe_prior_trap = (prior_trap_count != 0);
1672 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1673 ProfileData* pdata = NULL;
1674
1675
1676 // For reasons which are recorded per bytecode, we check per-BCI data.
1677 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1678 if (per_bc_reason != Reason_none) {
1679 // Find the profile data for this BCI. If there isn't one,
1680 // try to allocate one from the MDO's set of spares.
1681 // This will let us detect a repeated trap at this point.
1682 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1683
1684 if (pdata != NULL) {
1685 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1686 if (LogCompilation && xtty != NULL) {
1687 ttyLocker ttyl;
1688 // no more room for speculative traps in this MDO
1689 xtty->elem("speculative_traps_oom");
1690 }
1691 }
1692 // Query the trap state of this profile datum.
1693 int tstate0 = pdata->trap_state();
1694 if (!trap_state_has_reason(tstate0, per_bc_reason))
1695 maybe_prior_trap = false;
1696 if (!trap_state_is_recompiled(tstate0))
1697 maybe_prior_recompile = false;
1698
1699 // Update the trap state of this profile datum.
1700 int tstate1 = tstate0;
1701 // Record the reason.
1702 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1703 // Store the updated state on the MDO, for next time.
1704 if (tstate1 != tstate0)
1705 pdata->set_trap_state(tstate1);
1706 } else {
1707 if (LogCompilation && xtty != NULL) {
1708 ttyLocker ttyl;
1709 // Missing MDP? Leave a small complaint in the log.
1710 xtty->elem("missing_mdp bci='%d'", trap_bci);
1711 }
1712 }
1713 }
1714
1715 // Return results:
1716 ret_this_trap_count = this_trap_count;
1717 ret_maybe_prior_trap = maybe_prior_trap;
1718 ret_maybe_prior_recompile = maybe_prior_recompile;
1719 return pdata;
1720 }
1721
1722 void
1723 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1724 ResourceMark rm;
1725 // Ignored outputs:
1726 uint ignore_this_trap_count;
1727 bool ignore_maybe_prior_trap;
1728 bool ignore_maybe_prior_recompile;
1729 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1730 query_update_method_data(trap_mdo, trap_bci,
1731 (DeoptReason)reason,
1732 NULL,
1733 ignore_this_trap_count,
1734 ignore_maybe_prior_trap,
1735 ignore_maybe_prior_recompile);
1736 }
1737
1738 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1739
1740 // Still in Java no safepoints
1741 {
1742 // This enters VM and may safepoint
1743 uncommon_trap_inner(thread, trap_request);
1744 }
1745 return fetch_unroll_info_helper(thread);
1746 }
1747
1748 // Local derived constants.
1749 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1750 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1751 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1752
1753 //---------------------------trap_state_reason---------------------------------
1754 Deoptimization::DeoptReason
1755 Deoptimization::trap_state_reason(int trap_state) {
1756 // This assert provides the link between the width of DataLayout::trap_bits
1757 // and the encoding of "recorded" reasons. It ensures there are enough
1758 // bits to store all needed reasons in the per-BCI MDO profile.
1759 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1760 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1761 trap_state -= recompile_bit;
1762 if (trap_state == DS_REASON_MASK) {
1763 return Reason_many;
1764 } else {
1765 assert((int)Reason_none == 0, "state=0 => Reason_none");
1766 return (DeoptReason)trap_state;
1767 }
1768 }
1769 //-------------------------trap_state_has_reason-------------------------------
1770 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1771 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1772 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1773 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1774 trap_state -= recompile_bit;
1775 if (trap_state == DS_REASON_MASK) {
1776 return -1; // true, unspecifically (bottom of state lattice)
1777 } else if (trap_state == reason) {
1778 return 1; // true, definitely
1779 } else if (trap_state == 0) {
1780 return 0; // false, definitely (top of state lattice)
1781 } else {
1782 return 0; // false, definitely
1783 }
1784 }
1785 //-------------------------trap_state_add_reason-------------------------------
1786 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1787 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1788 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1789 trap_state -= recompile_bit;
1790 if (trap_state == DS_REASON_MASK) {
1791 return trap_state + recompile_bit; // already at state lattice bottom
1792 } else if (trap_state == reason) {
1793 return trap_state + recompile_bit; // the condition is already true
1794 } else if (trap_state == 0) {
1795 return reason + recompile_bit; // no condition has yet been true
1796 } else {
1797 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1798 }
1799 }
1800 //-----------------------trap_state_is_recompiled------------------------------
1801 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1802 return (trap_state & DS_RECOMPILE_BIT) != 0;
1803 }
1804 //-----------------------trap_state_set_recompiled-----------------------------
1805 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1806 if (z) return trap_state | DS_RECOMPILE_BIT;
1807 else return trap_state & ~DS_RECOMPILE_BIT;
1808 }
1809 //---------------------------format_trap_state---------------------------------
1810 // This is used for debugging and diagnostics, including LogFile output.
1811 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1812 int trap_state) {
1813 DeoptReason reason = trap_state_reason(trap_state);
1814 bool recomp_flag = trap_state_is_recompiled(trap_state);
1815 // Re-encode the state from its decoded components.
1816 int decoded_state = 0;
1817 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1818 decoded_state = trap_state_add_reason(decoded_state, reason);
1819 if (recomp_flag)
1820 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1821 // If the state re-encodes properly, format it symbolically.
1822 // Because this routine is used for debugging and diagnostics,
1823 // be robust even if the state is a strange value.
1824 size_t len;
1825 if (decoded_state != trap_state) {
1826 // Random buggy state that doesn't decode??
1827 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1828 } else {
1829 len = jio_snprintf(buf, buflen, "%s%s",
1830 trap_reason_name(reason),
1831 recomp_flag ? " recompiled" : "");
1832 }
1833 if (len >= buflen)
1834 buf[buflen-1] = '\0';
1835 return buf;
1836 }
1837
1838
1839 //--------------------------------statics--------------------------------------
1840 const char* Deoptimization::_trap_reason_name[] = {
1841 // Note: Keep this in sync. with enum DeoptReason.
1842 "none",
1843 "null_check",
1844 "null_assert",
1845 "range_check",
1846 "class_check",
1847 "array_check",
1848 "intrinsic",
1849 "bimorphic",
1850 "unloaded",
1851 "uninitialized",
1852 "unreached",
1853 "unhandled",
1854 "constraint",
1855 "div0_check",
1856 "age",
1857 "predicate",
1858 "loop_limit_check",
1859 "speculate_class_check",
1860 "speculate_null_check",
1861 "rtm_state_change",
1862 "unstable_if",
1863 "tenured"
1864 };
1865 const char* Deoptimization::_trap_action_name[] = {
1866 // Note: Keep this in sync. with enum DeoptAction.
1867 "none",
1868 "maybe_recompile",
1869 "reinterpret",
1870 "make_not_entrant",
1871 "make_not_compilable"
1872 };
1873
1874 const char* Deoptimization::trap_reason_name(int reason) {
1875 // Check that every reason has a name
1876 STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
1877
1878 if (reason == Reason_many) return "many";
1879 if ((uint)reason < Reason_LIMIT)
1880 return _trap_reason_name[reason];
1881 static char buf[20];
1882 sprintf(buf, "reason%d", reason);
1883 return buf;
1884 }
1885 const char* Deoptimization::trap_action_name(int action) {
1886 // Check that every action has a name
1887 STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
1888
1889 if ((uint)action < Action_LIMIT)
1890 return _trap_action_name[action];
1891 static char buf[20];
1892 sprintf(buf, "action%d", action);
1893 return buf;
1894 }
1895
1896 // This is used for debugging and diagnostics, including LogFile output.
1897 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1898 int trap_request) {
1899 jint unloaded_class_index = trap_request_index(trap_request);
1900 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1901 const char* action = trap_action_name(trap_request_action(trap_request));
1902 size_t len;
1903 if (unloaded_class_index < 0) {
1904 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1905 reason, action);
1906 } else {
1907 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1908 reason, action, unloaded_class_index);
1909 }
1910 if (len >= buflen)
1911 buf[buflen-1] = '\0';
1912 return buf;
1913 }
1914
1915 juint Deoptimization::_deoptimization_hist
1916 [Deoptimization::Reason_LIMIT]
1917 [1 + Deoptimization::Action_LIMIT]
1918 [Deoptimization::BC_CASE_LIMIT]
1919 = {0};
1920
1921 enum {
1922 LSB_BITS = 8,
1923 LSB_MASK = right_n_bits(LSB_BITS)
1924 };
1925
1926 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1927 Bytecodes::Code bc) {
1928 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1929 assert(action >= 0 && action < Action_LIMIT, "oob");
1930 _deoptimization_hist[Reason_none][0][0] += 1; // total
1931 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1932 juint* cases = _deoptimization_hist[reason][1+action];
1933 juint* bc_counter_addr = NULL;
1934 juint bc_counter = 0;
1935 // Look for an unused counter, or an exact match to this BC.
1936 if (bc != Bytecodes::_illegal) {
1937 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1938 juint* counter_addr = &cases[bc_case];
1939 juint counter = *counter_addr;
1940 if ((counter == 0 && bc_counter_addr == NULL)
1941 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1942 // this counter is either free or is already devoted to this BC
1943 bc_counter_addr = counter_addr;
1944 bc_counter = counter | bc;
1945 }
1946 }
1947 }
1948 if (bc_counter_addr == NULL) {
1949 // Overflow, or no given bytecode.
1950 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1951 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1952 }
1953 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1954 }
1955
1956 jint Deoptimization::total_deoptimization_count() {
1957 return _deoptimization_hist[Reason_none][0][0];
1958 }
1959
1960 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1961 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1962 return _deoptimization_hist[reason][0][0];
1963 }
1964
1965 void Deoptimization::print_statistics() {
1966 juint total = total_deoptimization_count();
1967 juint account = total;
1968 if (total != 0) {
1969 ttyLocker ttyl;
1970 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1971 tty->print_cr("Deoptimization traps recorded:");
1972 #define PRINT_STAT_LINE(name, r) \
1973 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1974 PRINT_STAT_LINE("total", total);
1975 // For each non-zero entry in the histogram, print the reason,
1976 // the action, and (if specifically known) the type of bytecode.
1977 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1978 for (int action = 0; action < Action_LIMIT; action++) {
1979 juint* cases = _deoptimization_hist[reason][1+action];
1980 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1981 juint counter = cases[bc_case];
1982 if (counter != 0) {
1983 char name[1*K];
1984 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1985 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1986 bc = Bytecodes::_illegal;
1987 sprintf(name, "%s/%s/%s",
1988 trap_reason_name(reason),
1989 trap_action_name(action),
1990 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1991 juint r = counter >> LSB_BITS;
1992 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1993 account -= r;
1994 }
1995 }
1996 }
1997 }
1998 if (account != 0) {
1999 PRINT_STAT_LINE("unaccounted", account);
2000 }
2001 #undef PRINT_STAT_LINE
2002 if (xtty != NULL) xtty->tail("statistics");
2003 }
2004 }
2005 #else // COMPILER2 || SHARK
2006
2007
2008 // Stubs for C1 only system.
2009 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2010 return false;
2011 }
2012
2013 const char* Deoptimization::trap_reason_name(int reason) {
2014 return "unknown";
2015 }
2016
2017 void Deoptimization::print_statistics() {
2018 // no output
2019 }
2020
2021 void
2022 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2023 // no udpate
2024 }
2025
2026 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2027 return 0;
2028 }
2029
2030 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2031 Bytecodes::Code bc) {
2032 // no update
2033 }
2034
2035 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2036 int trap_state) {
2037 jio_snprintf(buf, buflen, "#%d", trap_state);
2038 return buf;
2039 }
2040
2041 #endif // COMPILER2 || SHARK