1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/methodOop.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef COMPILER2
63 #ifdef TARGET_ARCH_MODEL_x86_32
64 # include "adfiles/ad_x86_32.hpp"
65 #endif
66 #ifdef TARGET_ARCH_MODEL_x86_64
67 # include "adfiles/ad_x86_64.hpp"
68 #endif
69 #ifdef TARGET_ARCH_MODEL_sparc
70 # include "adfiles/ad_sparc.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_zero
73 # include "adfiles/ad_zero.hpp"
74 #endif
75 #endif
76
77 bool DeoptimizationMarker::_is_active = false;
78
79 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
80 int caller_adjustment,
81 int number_of_frames,
82 intptr_t* frame_sizes,
83 address* frame_pcs,
84 BasicType return_type) {
85 _size_of_deoptimized_frame = size_of_deoptimized_frame;
86 _caller_adjustment = caller_adjustment;
87 _number_of_frames = number_of_frames;
88 _frame_sizes = frame_sizes;
89 _frame_pcs = frame_pcs;
90 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
91 _return_type = return_type;
92 // PD (x86 only)
93 _counter_temp = 0;
94 _initial_fp = 0;
95 _unpack_kind = 0;
96 _sender_sp_temp = 0;
97
98 _total_frame_sizes = size_of_frames();
99 }
100
101
102 Deoptimization::UnrollBlock::~UnrollBlock() {
103 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
104 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
105 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
106 }
107
108
109 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
110 assert(register_number < RegisterMap::reg_count, "checking register number");
111 return &_register_block[register_number * 2];
112 }
113
114
115
116 int Deoptimization::UnrollBlock::size_of_frames() const {
117 // Acount first for the adjustment of the initial frame
118 int result = _caller_adjustment;
119 for (int index = 0; index < number_of_frames(); index++) {
120 result += frame_sizes()[index];
121 }
122 return result;
123 }
124
125
126 void Deoptimization::UnrollBlock::print() {
127 ttyLocker ttyl;
128 tty->print_cr("UnrollBlock");
129 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
130 tty->print( " frame_sizes: ");
131 for (int index = 0; index < number_of_frames(); index++) {
132 tty->print("%d ", frame_sizes()[index]);
133 }
134 tty->cr();
135 }
136
137
138 // In order to make fetch_unroll_info work properly with escape
139 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
140 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
141 // of previously eliminated objects occurs in realloc_objects, which is
142 // called from the method fetch_unroll_info_helper below.
143 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
144 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
145 // but makes the entry a little slower. There is however a little dance we have to
146 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
147
148 // fetch_unroll_info() is called at the beginning of the deoptimization
149 // handler. Note this fact before we start generating temporary frames
150 // that can confuse an asynchronous stack walker. This counter is
151 // decremented at the end of unpack_frames().
152 thread->inc_in_deopt_handler();
153
154 return fetch_unroll_info_helper(thread);
155 JRT_END
156
157
158 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
159 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
160
161 // Note: there is a safepoint safety issue here. No matter whether we enter
162 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
163 // the vframeArray is created.
164 //
165
166 // Allocate our special deoptimization ResourceMark
167 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
168 assert(thread->deopt_mark() == NULL, "Pending deopt!");
169 thread->set_deopt_mark(dmark);
170
171 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
172 RegisterMap map(thread, true);
173 RegisterMap dummy_map(thread, false);
174 // Now get the deoptee with a valid map
175 frame deoptee = stub_frame.sender(&map);
176
177 // Create a growable array of VFrames where each VFrame represents an inlined
178 // Java frame. This storage is allocated with the usual system arena.
179 assert(deoptee.is_compiled_frame(), "Wrong frame type");
180 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
181 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
182 while (!vf->is_top()) {
183 assert(vf->is_compiled_frame(), "Wrong frame type");
184 chunk->push(compiledVFrame::cast(vf));
185 vf = vf->sender();
186 }
187 assert(vf->is_compiled_frame(), "Wrong frame type");
188 chunk->push(compiledVFrame::cast(vf));
189
190 #ifdef COMPILER2
191 // Reallocate the non-escaping objects and restore their fields. Then
192 // relock objects if synchronization on them was eliminated.
193 if (DoEscapeAnalysis) {
194 if (EliminateAllocations) {
195 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
196 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
197
198 // The flag return_oop() indicates call sites which return oop
199 // in compiled code. Such sites include java method calls,
200 // runtime calls (for example, used to allocate new objects/arrays
201 // on slow code path) and any other calls generated in compiled code.
202 // It is not guaranteed that we can get such information here only
203 // by analyzing bytecode in deoptimized frames. This is why this flag
204 // is set during method compilation (see Compile::Process_OopMap_Node()).
205 bool save_oop_result = chunk->at(0)->scope()->return_oop();
206 Handle return_value;
207 if (save_oop_result) {
208 // Reallocation may trigger GC. If deoptimization happened on return from
209 // call which returns oop we need to save it since it is not in oopmap.
210 oop result = deoptee.saved_oop_result(&map);
211 assert(result == NULL || result->is_oop(), "must be oop");
212 return_value = Handle(thread, result);
213 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
214 if (TraceDeoptimization) {
215 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
216 }
217 }
218 bool reallocated = false;
219 if (objects != NULL) {
220 JRT_BLOCK
221 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
222 JRT_END
223 }
224 if (reallocated) {
225 reassign_fields(&deoptee, &map, objects);
226 #ifndef PRODUCT
227 if (TraceDeoptimization) {
228 ttyLocker ttyl;
229 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
230 print_objects(objects);
231 }
232 #endif
233 }
234 if (save_oop_result) {
235 // Restore result.
236 deoptee.set_saved_oop_result(&map, return_value());
237 }
238 }
239 if (EliminateLocks) {
240 #ifndef PRODUCT
241 bool first = true;
242 #endif
243 for (int i = 0; i < chunk->length(); i++) {
244 compiledVFrame* cvf = chunk->at(i);
245 assert (cvf->scope() != NULL,"expect only compiled java frames");
246 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
247 if (monitors->is_nonempty()) {
248 relock_objects(monitors, thread);
249 #ifndef PRODUCT
250 if (TraceDeoptimization) {
251 ttyLocker ttyl;
252 for (int j = 0; j < monitors->length(); j++) {
253 MonitorInfo* mi = monitors->at(j);
254 if (mi->eliminated()) {
255 if (first) {
256 first = false;
257 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
258 }
259 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
260 }
261 }
262 }
263 #endif
264 }
265 }
266 }
267 }
268 #endif // COMPILER2
269 // Ensure that no safepoint is taken after pointers have been stored
270 // in fields of rematerialized objects. If a safepoint occurs from here on
271 // out the java state residing in the vframeArray will be missed.
272 No_Safepoint_Verifier no_safepoint;
273
274 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
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 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
322 #endif
323 #else
324 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
325 #endif // !SHARK
326
327 // This is a guarantee instead of an assert because if vframe doesn't match
328 // we will unpack the wrong deoptimized frame and wind up in strange places
329 // where it will be very difficult to figure out what went wrong. Better
330 // to die an early death here than some very obscure death later when the
331 // trail is cold.
332 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
333 // in that it will fail to detect a problem when there is one. This needs
334 // more work in tiger timeframe.
335 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
336
337 int number_of_frames = array->frames();
338
339 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
340 // virtual activation, which is the reverse of the elements in the vframes array.
341 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
342 // +1 because we always have an interpreter return address for the final slot.
343 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
344 int callee_parameters = 0;
345 int callee_locals = 0;
346 int popframe_extra_args = 0;
347 // Create an interpreter return address for the stub to use as its return
348 // address so the skeletal frames are perfectly walkable
349 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
350
351 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
352 // activation be put back on the expression stack of the caller for reexecution
353 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
354 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
355 }
356
357 //
358 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
359 // frame_sizes/frame_pcs[1] next oldest frame (int)
360 // frame_sizes/frame_pcs[n] youngest frame (int)
361 //
362 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
363 // owns the space for the return address to it's caller). Confusing ain't it.
364 //
365 // The vframe array can address vframes with indices running from
366 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
367 // When we create the skeletal frames we need the oldest frame to be in the zero slot
368 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
369 // so things look a little strange in this loop.
370 //
371 for (int index = 0; index < array->frames(); index++ ) {
372 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
373 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
374 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
375 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
376 callee_locals,
377 index == 0,
378 popframe_extra_args);
379 // This pc doesn't have to be perfect just good enough to identify the frame
380 // as interpreted so the skeleton frame will be walkable
381 // The correct pc will be set when the skeleton frame is completely filled out
382 // The final pc we store in the loop is wrong and will be overwritten below
383 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
384
385 callee_parameters = array->element(index)->method()->size_of_parameters();
386 callee_locals = array->element(index)->method()->max_locals();
387 popframe_extra_args = 0;
388 }
389
390 // Compute whether the root vframe returns a float or double value.
391 BasicType return_type;
392 {
393 HandleMark hm;
394 methodHandle method(thread, array->element(0)->method());
395 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci());
396 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL;
397 }
398
399 // Compute information for handling adapters and adjusting the frame size of the caller.
400 int caller_adjustment = 0;
401
402 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
403 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
404 // than simply use array->sender.pc(). This requires us to walk the current set of frames
405 //
406 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
407 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
408
409 // Compute the amount the oldest interpreter frame will have to adjust
410 // its caller's stack by. If the caller is a compiled frame then
411 // we pretend that the callee has no parameters so that the
412 // extension counts for the full amount of locals and not just
413 // locals-parms. This is because without a c2i adapter the parm
414 // area as created by the compiled frame will not be usable by
415 // the interpreter. (Depending on the calling convention there
416 // may not even be enough space).
417
418 // QQQ I'd rather see this pushed down into last_frame_adjust
419 // and have it take the sender (aka caller).
420
421 if (deopt_sender.is_compiled_frame()) {
422 caller_adjustment = last_frame_adjust(0, callee_locals);
423 } else if (callee_locals > callee_parameters) {
424 // The caller frame may need extending to accommodate
425 // non-parameter locals of the first unpacked interpreted frame.
426 // Compute that adjustment.
427 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
428 }
429
430
431 // If the sender is deoptimized the we must retrieve the address of the handler
432 // since the frame will "magically" show the original pc before the deopt
433 // and we'd undo the deopt.
434
435 frame_pcs[0] = deopt_sender.raw_pc();
436
437 #ifndef SHARK
438 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
439 #endif // SHARK
440
441 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
442 caller_adjustment * BytesPerWord,
443 number_of_frames,
444 frame_sizes,
445 frame_pcs,
446 return_type);
447 #if defined(IA32) || defined(AMD64)
448 // We need a way to pass fp to the unpacking code so the skeletal frames
449 // come out correct. This is only needed for x86 because of c2 using ebp
450 // as an allocatable register. So this update is useless (and harmless)
451 // on the other platforms. It would be nice to do this in a different
452 // way but even the old style deoptimization had a problem with deriving
453 // this value. NEEDS_CLEANUP
454 // Note: now that c1 is using c2's deopt blob we must do this on all
455 // x86 based platforms
456 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
457 *fp_addr = array->sender().fp(); // was adapter_caller
458 #endif /* IA32 || AMD64 */
459
460 if (array->frames() > 1) {
461 if (VerifyStack && TraceDeoptimization) {
462 tty->print_cr("Deoptimizing method containing inlining");
463 }
464 }
465
466 array->set_unroll_block(info);
467 return info;
468 }
469
470 // Called to cleanup deoptimization data structures in normal case
471 // after unpacking to stack and when stack overflow error occurs
472 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
473 vframeArray *array) {
474
475 // Get array if coming from exception
476 if (array == NULL) {
477 array = thread->vframe_array_head();
478 }
479 thread->set_vframe_array_head(NULL);
480
481 // Free the previous UnrollBlock
482 vframeArray* old_array = thread->vframe_array_last();
483 thread->set_vframe_array_last(array);
484
485 if (old_array != NULL) {
486 UnrollBlock* old_info = old_array->unroll_block();
487 old_array->set_unroll_block(NULL);
488 delete old_info;
489 delete old_array;
490 }
491
492 // Deallocate any resource creating in this routine and any ResourceObjs allocated
493 // inside the vframeArray (StackValueCollections)
494
495 delete thread->deopt_mark();
496 thread->set_deopt_mark(NULL);
497
498
499 if (JvmtiExport::can_pop_frame()) {
500 #ifndef CC_INTERP
501 // Regardless of whether we entered this routine with the pending
502 // popframe condition bit set, we should always clear it now
503 thread->clear_popframe_condition();
504 #else
505 // C++ interpeter will clear has_pending_popframe when it enters
506 // with method_resume. For deopt_resume2 we clear it now.
507 if (thread->popframe_forcing_deopt_reexecution())
508 thread->clear_popframe_condition();
509 #endif /* CC_INTERP */
510 }
511
512 // unpack_frames() is called at the end of the deoptimization handler
513 // and (in C2) at the end of the uncommon trap handler. Note this fact
514 // so that an asynchronous stack walker can work again. This counter is
515 // incremented at the beginning of fetch_unroll_info() and (in C2) at
516 // the beginning of uncommon_trap().
517 thread->dec_in_deopt_handler();
518 }
519
520
521 // Return BasicType of value being returned
522 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
523
524 // We are already active int he special DeoptResourceMark any ResourceObj's we
525 // allocate will be freed at the end of the routine.
526
527 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
528 // but makes the entry a little slower. There is however a little dance we have to
529 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
530 ResetNoHandleMark rnhm; // No-op in release/product versions
531 HandleMark hm;
532
533 frame stub_frame = thread->last_frame();
534
535 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
536 // must point to the vframeArray for the unpack frame.
537 vframeArray* array = thread->vframe_array_head();
538
539 #ifndef PRODUCT
540 if (TraceDeoptimization) {
541 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
542 }
543 #endif
544
545 UnrollBlock* info = array->unroll_block();
546
547 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
548 array->unpack_to_stack(stub_frame, exec_mode);
549
550 BasicType bt = info->return_type();
551
552 // If we have an exception pending, claim that the return type is an oop
553 // so the deopt_blob does not overwrite the exception_oop.
554
555 if (exec_mode == Unpack_exception)
556 bt = T_OBJECT;
557
558 // Cleanup thread deopt data
559 cleanup_deopt_info(thread, array);
560
561 #ifndef PRODUCT
562 if (VerifyStack) {
563 ResourceMark res_mark;
564
565 // Verify that the just-unpacked frames match the interpreter's
566 // notions of expression stack and locals
567 vframeArray* cur_array = thread->vframe_array_last();
568 RegisterMap rm(thread, false);
569 rm.set_include_argument_oops(false);
570 bool is_top_frame = true;
571 int callee_size_of_parameters = 0;
572 int callee_max_locals = 0;
573 for (int i = 0; i < cur_array->frames(); i++) {
574 vframeArrayElement* el = cur_array->element(i);
575 frame* iframe = el->iframe();
576 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
577
578 // Get the oop map for this bci
579 InterpreterOopMap mask;
580 int cur_invoke_parameter_size = 0;
581 bool try_next_mask = false;
582 int next_mask_expression_stack_size = -1;
583 int top_frame_expression_stack_adjustment = 0;
584 methodHandle mh(thread, iframe->interpreter_frame_method());
585 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
586 BytecodeStream str(mh);
587 str.set_start(iframe->interpreter_frame_bci());
588 int max_bci = mh->code_size();
589 // Get to the next bytecode if possible
590 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
591 // Check to see if we can grab the number of outgoing arguments
592 // at an uncommon trap for an invoke (where the compiler
593 // generates debug info before the invoke has executed)
594 Bytecodes::Code cur_code = str.next();
595 if (cur_code == Bytecodes::_invokevirtual ||
596 cur_code == Bytecodes::_invokespecial ||
597 cur_code == Bytecodes::_invokestatic ||
598 cur_code == Bytecodes::_invokeinterface) {
599 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci());
600 symbolHandle signature(thread, invoke->signature());
601 ArgumentSizeComputer asc(signature);
602 cur_invoke_parameter_size = asc.size();
603 if (cur_code != Bytecodes::_invokestatic) {
604 // Add in receiver
605 ++cur_invoke_parameter_size;
606 }
607 }
608 if (str.bci() < max_bci) {
609 Bytecodes::Code bc = str.next();
610 if (bc >= 0) {
611 // The interpreter oop map generator reports results before
612 // the current bytecode has executed except in the case of
613 // calls. It seems to be hard to tell whether the compiler
614 // has emitted debug information matching the "state before"
615 // a given bytecode or the state after, so we try both
616 switch (cur_code) {
617 case Bytecodes::_invokevirtual:
618 case Bytecodes::_invokespecial:
619 case Bytecodes::_invokestatic:
620 case Bytecodes::_invokeinterface:
621 case Bytecodes::_athrow:
622 break;
623 default: {
624 InterpreterOopMap next_mask;
625 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
626 next_mask_expression_stack_size = next_mask.expression_stack_size();
627 // Need to subtract off the size of the result type of
628 // the bytecode because this is not described in the
629 // debug info but returned to the interpreter in the TOS
630 // caching register
631 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
632 if (bytecode_result_type != T_ILLEGAL) {
633 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
634 }
635 assert(top_frame_expression_stack_adjustment >= 0, "");
636 try_next_mask = true;
637 break;
638 }
639 }
640 }
641 }
642
643 // Verify stack depth and oops in frame
644 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
645 if (!(
646 /* SPARC */
647 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
648 /* x86 */
649 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
650 (try_next_mask &&
651 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
652 top_frame_expression_stack_adjustment))) ||
653 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
654 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
655 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
656 )) {
657 ttyLocker ttyl;
658
659 // Print out some information that will help us debug the problem
660 tty->print_cr("Wrong number of expression stack elements during deoptimization");
661 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
662 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
663 iframe->interpreter_frame_expression_stack_size());
664 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
665 tty->print_cr(" try_next_mask = %d", try_next_mask);
666 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
667 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
668 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
669 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
670 tty->print_cr(" exec_mode = %d", exec_mode);
671 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
672 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
673 tty->print_cr(" Interpreted frames:");
674 for (int k = 0; k < cur_array->frames(); k++) {
675 vframeArrayElement* el = cur_array->element(k);
676 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
677 }
678 cur_array->print_on_2(tty);
679 guarantee(false, "wrong number of expression stack elements during deopt");
680 }
681 VerifyOopClosure verify;
682 iframe->oops_interpreted_do(&verify, &rm, false);
683 callee_size_of_parameters = mh->size_of_parameters();
684 callee_max_locals = mh->max_locals();
685 is_top_frame = false;
686 }
687 }
688 #endif /* !PRODUCT */
689
690
691 return bt;
692 JRT_END
693
694
695 int Deoptimization::deoptimize_dependents() {
696 Threads::deoptimized_wrt_marked_nmethods();
697 return 0;
698 }
699
700
701 #ifdef COMPILER2
702 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
703 Handle pending_exception(thread->pending_exception());
704 const char* exception_file = thread->exception_file();
705 int exception_line = thread->exception_line();
706 thread->clear_pending_exception();
707
708 for (int i = 0; i < objects->length(); i++) {
709 assert(objects->at(i)->is_object(), "invalid debug information");
710 ObjectValue* sv = (ObjectValue*) objects->at(i);
711
712 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
713 oop obj = NULL;
714
715 if (k->oop_is_instance()) {
716 instanceKlass* ik = instanceKlass::cast(k());
717 obj = ik->allocate_instance(CHECK_(false));
718 } else if (k->oop_is_typeArray()) {
719 typeArrayKlass* ak = typeArrayKlass::cast(k());
720 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
721 int len = sv->field_size() / type2size[ak->element_type()];
722 obj = ak->allocate(len, CHECK_(false));
723 } else if (k->oop_is_objArray()) {
724 objArrayKlass* ak = objArrayKlass::cast(k());
725 obj = ak->allocate(sv->field_size(), CHECK_(false));
726 }
727
728 assert(obj != NULL, "allocation failed");
729 assert(sv->value().is_null(), "redundant reallocation");
730 sv->set_value(obj);
731 }
732
733 if (pending_exception.not_null()) {
734 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
735 }
736
737 return true;
738 }
739
740 // This assumes that the fields are stored in ObjectValue in the same order
741 // they are yielded by do_nonstatic_fields.
742 class FieldReassigner: public FieldClosure {
743 frame* _fr;
744 RegisterMap* _reg_map;
745 ObjectValue* _sv;
746 instanceKlass* _ik;
747 oop _obj;
748
749 int _i;
750 public:
751 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
752 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
753
754 int i() const { return _i; }
755
756
757 void do_field(fieldDescriptor* fd) {
758 intptr_t val;
759 StackValue* value =
760 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
761 int offset = fd->offset();
762 switch (fd->field_type()) {
763 case T_OBJECT: case T_ARRAY:
764 assert(value->type() == T_OBJECT, "Agreement.");
765 _obj->obj_field_put(offset, value->get_obj()());
766 break;
767
768 case T_LONG: case T_DOUBLE: {
769 assert(value->type() == T_INT, "Agreement.");
770 StackValue* low =
771 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
772 #ifdef _LP64
773 jlong res = (jlong)low->get_int();
774 #else
775 #ifdef SPARC
776 // For SPARC we have to swap high and low words.
777 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
778 #else
779 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
780 #endif //SPARC
781 #endif
782 _obj->long_field_put(offset, res);
783 break;
784 }
785 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
786 case T_INT: case T_FLOAT: // 4 bytes.
787 assert(value->type() == T_INT, "Agreement.");
788 val = value->get_int();
789 _obj->int_field_put(offset, (jint)*((jint*)&val));
790 break;
791
792 case T_SHORT: case T_CHAR: // 2 bytes
793 assert(value->type() == T_INT, "Agreement.");
794 val = value->get_int();
795 _obj->short_field_put(offset, (jshort)*((jint*)&val));
796 break;
797
798 case T_BOOLEAN: case T_BYTE: // 1 byte
799 assert(value->type() == T_INT, "Agreement.");
800 val = value->get_int();
801 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
802 break;
803
804 default:
805 ShouldNotReachHere();
806 }
807 _i++;
808 }
809 };
810
811 // restore elements of an eliminated type array
812 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
813 int index = 0;
814 intptr_t val;
815
816 for (int i = 0; i < sv->field_size(); i++) {
817 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
818 switch(type) {
819 case T_LONG: case T_DOUBLE: {
820 assert(value->type() == T_INT, "Agreement.");
821 StackValue* low =
822 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
823 #ifdef _LP64
824 jlong res = (jlong)low->get_int();
825 #else
826 #ifdef SPARC
827 // For SPARC we have to swap high and low words.
828 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
829 #else
830 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
831 #endif //SPARC
832 #endif
833 obj->long_at_put(index, res);
834 break;
835 }
836
837 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
838 case T_INT: case T_FLOAT: // 4 bytes.
839 assert(value->type() == T_INT, "Agreement.");
840 val = value->get_int();
841 obj->int_at_put(index, (jint)*((jint*)&val));
842 break;
843
844 case T_SHORT: case T_CHAR: // 2 bytes
845 assert(value->type() == T_INT, "Agreement.");
846 val = value->get_int();
847 obj->short_at_put(index, (jshort)*((jint*)&val));
848 break;
849
850 case T_BOOLEAN: case T_BYTE: // 1 byte
851 assert(value->type() == T_INT, "Agreement.");
852 val = value->get_int();
853 obj->bool_at_put(index, (jboolean)*((jint*)&val));
854 break;
855
856 default:
857 ShouldNotReachHere();
858 }
859 index++;
860 }
861 }
862
863
864 // restore fields of an eliminated object array
865 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
866 for (int i = 0; i < sv->field_size(); i++) {
867 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
868 assert(value->type() == T_OBJECT, "object element expected");
869 obj->obj_at_put(i, value->get_obj()());
870 }
871 }
872
873
874 // restore fields of all eliminated objects and arrays
875 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
876 for (int i = 0; i < objects->length(); i++) {
877 ObjectValue* sv = (ObjectValue*) objects->at(i);
878 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
879 Handle obj = sv->value();
880 assert(obj.not_null(), "reallocation was missed");
881
882 if (k->oop_is_instance()) {
883 instanceKlass* ik = instanceKlass::cast(k());
884 FieldReassigner reassign(fr, reg_map, sv, obj());
885 ik->do_nonstatic_fields(&reassign);
886 } else if (k->oop_is_typeArray()) {
887 typeArrayKlass* ak = typeArrayKlass::cast(k());
888 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
889 } else if (k->oop_is_objArray()) {
890 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
891 }
892 }
893 }
894
895
896 // relock objects for which synchronization was eliminated
897 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
898 for (int i = 0; i < monitors->length(); i++) {
899 MonitorInfo* mon_info = monitors->at(i);
900 if (mon_info->eliminated()) {
901 assert(mon_info->owner() != NULL, "reallocation was missed");
902 Handle obj = Handle(mon_info->owner());
903 markOop mark = obj->mark();
904 if (UseBiasedLocking && mark->has_bias_pattern()) {
905 // New allocated objects may have the mark set to anonymously biased.
906 // Also the deoptimized method may called methods with synchronization
907 // where the thread-local object is bias locked to the current thread.
908 assert(mark->is_biased_anonymously() ||
909 mark->biased_locker() == thread, "should be locked to current thread");
910 // Reset mark word to unbiased prototype.
911 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
912 obj->set_mark(unbiased_prototype);
913 }
914 BasicLock* lock = mon_info->lock();
915 ObjectSynchronizer::slow_enter(obj, lock, thread);
916 }
917 assert(mon_info->owner()->is_locked(), "object must be locked now");
918 }
919 }
920
921
922 #ifndef PRODUCT
923 // print information about reallocated objects
924 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
925 fieldDescriptor fd;
926
927 for (int i = 0; i < objects->length(); i++) {
928 ObjectValue* sv = (ObjectValue*) objects->at(i);
929 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
930 Handle obj = sv->value();
931
932 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
933 k->as_klassOop()->print_value();
934 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
935 tty->cr();
936
937 if (Verbose) {
938 k->oop_print_on(obj(), tty);
939 }
940 }
941 }
942 #endif
943 #endif // COMPILER2
944
945 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
946
947 #ifndef PRODUCT
948 if (TraceDeoptimization) {
949 ttyLocker ttyl;
950 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
951 fr.print_on(tty);
952 tty->print_cr(" Virtual frames (innermost first):");
953 for (int index = 0; index < chunk->length(); index++) {
954 compiledVFrame* vf = chunk->at(index);
955 tty->print(" %2d - ", index);
956 vf->print_value();
957 int bci = chunk->at(index)->raw_bci();
958 const char* code_name;
959 if (bci == SynchronizationEntryBCI) {
960 code_name = "sync entry";
961 } else {
962 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci);
963 code_name = Bytecodes::name(code);
964 }
965 tty->print(" - %s", code_name);
966 tty->print_cr(" @ bci %d ", bci);
967 if (Verbose) {
968 vf->print();
969 tty->cr();
970 }
971 }
972 }
973 #endif
974
975 // Register map for next frame (used for stack crawl). We capture
976 // the state of the deopt'ing frame's caller. Thus if we need to
977 // stuff a C2I adapter we can properly fill in the callee-save
978 // register locations.
979 frame caller = fr.sender(reg_map);
980 int frame_size = caller.sp() - fr.sp();
981
982 frame sender = caller;
983
984 // Since the Java thread being deoptimized will eventually adjust it's own stack,
985 // the vframeArray containing the unpacking information is allocated in the C heap.
986 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
987 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
988
989 // Compare the vframeArray to the collected vframes
990 assert(array->structural_compare(thread, chunk), "just checking");
991 Events::log("# vframes = %d", (intptr_t)chunk->length());
992
993 #ifndef PRODUCT
994 if (TraceDeoptimization) {
995 ttyLocker ttyl;
996 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
997 }
998 #endif // PRODUCT
999
1000 return array;
1001 }
1002
1003
1004 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1005 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1006 for (int i = 0; i < monitors->length(); i++) {
1007 MonitorInfo* mon_info = monitors->at(i);
1008 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1009 objects_to_revoke->append(Handle(mon_info->owner()));
1010 }
1011 }
1012 }
1013
1014
1015 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1016 if (!UseBiasedLocking) {
1017 return;
1018 }
1019
1020 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1021
1022 // Unfortunately we don't have a RegisterMap available in most of
1023 // the places we want to call this routine so we need to walk the
1024 // stack again to update the register map.
1025 if (map == NULL || !map->update_map()) {
1026 StackFrameStream sfs(thread, true);
1027 bool found = false;
1028 while (!found && !sfs.is_done()) {
1029 frame* cur = sfs.current();
1030 sfs.next();
1031 found = cur->id() == fr.id();
1032 }
1033 assert(found, "frame to be deoptimized not found on target thread's stack");
1034 map = sfs.register_map();
1035 }
1036
1037 vframe* vf = vframe::new_vframe(&fr, map, thread);
1038 compiledVFrame* cvf = compiledVFrame::cast(vf);
1039 // Revoke monitors' biases in all scopes
1040 while (!cvf->is_top()) {
1041 collect_monitors(cvf, objects_to_revoke);
1042 cvf = compiledVFrame::cast(cvf->sender());
1043 }
1044 collect_monitors(cvf, objects_to_revoke);
1045
1046 if (SafepointSynchronize::is_at_safepoint()) {
1047 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1048 } else {
1049 BiasedLocking::revoke(objects_to_revoke);
1050 }
1051 }
1052
1053
1054 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1055 if (!UseBiasedLocking) {
1056 return;
1057 }
1058
1059 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1060 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1061 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1062 if (jt->has_last_Java_frame()) {
1063 StackFrameStream sfs(jt, true);
1064 while (!sfs.is_done()) {
1065 frame* cur = sfs.current();
1066 if (cb->contains(cur->pc())) {
1067 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1068 compiledVFrame* cvf = compiledVFrame::cast(vf);
1069 // Revoke monitors' biases in all scopes
1070 while (!cvf->is_top()) {
1071 collect_monitors(cvf, objects_to_revoke);
1072 cvf = compiledVFrame::cast(cvf->sender());
1073 }
1074 collect_monitors(cvf, objects_to_revoke);
1075 }
1076 sfs.next();
1077 }
1078 }
1079 }
1080 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1081 }
1082
1083
1084 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1085 assert(fr.can_be_deoptimized(), "checking frame type");
1086
1087 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1088
1089 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1090
1091 // Patch the nmethod so that when execution returns to it we will
1092 // deopt the execution state and return to the interpreter.
1093 fr.deoptimize(thread);
1094 }
1095
1096 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1097 // Deoptimize only if the frame comes from compile code.
1098 // Do not deoptimize the frame which is already patched
1099 // during the execution of the loops below.
1100 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1101 return;
1102 }
1103 ResourceMark rm;
1104 DeoptimizationMarker dm;
1105 if (UseBiasedLocking) {
1106 revoke_biases_of_monitors(thread, fr, map);
1107 }
1108 deoptimize_single_frame(thread, fr);
1109
1110 }
1111
1112
1113 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1114 // Compute frame and register map based on thread and sp.
1115 RegisterMap reg_map(thread, UseBiasedLocking);
1116 frame fr = thread->last_frame();
1117 while (fr.id() != id) {
1118 fr = fr.sender(®_map);
1119 }
1120 deoptimize(thread, fr, ®_map);
1121 }
1122
1123
1124 // JVMTI PopFrame support
1125 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1126 {
1127 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1128 }
1129 JRT_END
1130
1131
1132 #if defined(COMPILER2) || defined(SHARK)
1133 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1134 // in case of an unresolved klass entry, load the class.
1135 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1136 klassOop tk = constant_pool->klass_at(index, CHECK);
1137 return;
1138 }
1139
1140 if (!constant_pool->tag_at(index).is_symbol()) return;
1141
1142 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1143 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1144
1145 // class name?
1146 if (symbol->byte_at(0) != '(') {
1147 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1148 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1149 return;
1150 }
1151
1152 // then it must be a signature!
1153 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1154 if (ss.is_object()) {
1155 symbolOop s = ss.as_symbol(CHECK);
1156 symbolHandle class_name (THREAD, s);
1157 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1158 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1159 }
1160 }
1161 }
1162
1163
1164 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1165 EXCEPTION_MARK;
1166 load_class_by_index(constant_pool, index, THREAD);
1167 if (HAS_PENDING_EXCEPTION) {
1168 // Exception happened during classloading. We ignore the exception here, since it
1169 // is going to be rethrown since the current activation is going to be deoptimzied and
1170 // the interpreter will re-execute the bytecode.
1171 CLEAR_PENDING_EXCEPTION;
1172 }
1173 }
1174
1175 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1176 HandleMark hm;
1177
1178 // uncommon_trap() is called at the beginning of the uncommon trap
1179 // handler. Note this fact before we start generating temporary frames
1180 // that can confuse an asynchronous stack walker. This counter is
1181 // decremented at the end of unpack_frames().
1182 thread->inc_in_deopt_handler();
1183
1184 // We need to update the map if we have biased locking.
1185 RegisterMap reg_map(thread, UseBiasedLocking);
1186 frame stub_frame = thread->last_frame();
1187 frame fr = stub_frame.sender(®_map);
1188 // Make sure the calling nmethod is not getting deoptimized and removed
1189 // before we are done with it.
1190 nmethodLocker nl(fr.pc());
1191
1192 {
1193 ResourceMark rm;
1194
1195 // Revoke biases of any monitors in the frame to ensure we can migrate them
1196 revoke_biases_of_monitors(thread, fr, ®_map);
1197
1198 DeoptReason reason = trap_request_reason(trap_request);
1199 DeoptAction action = trap_request_action(trap_request);
1200 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1201
1202 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1203 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1204 compiledVFrame* cvf = compiledVFrame::cast(vf);
1205
1206 nmethod* nm = cvf->code();
1207
1208 ScopeDesc* trap_scope = cvf->scope();
1209 methodHandle trap_method = trap_scope->method();
1210 int trap_bci = trap_scope->bci();
1211 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code();
1212
1213 // Record this event in the histogram.
1214 gather_statistics(reason, action, trap_bc);
1215
1216 // Ensure that we can record deopt. history:
1217 bool create_if_missing = ProfileTraps;
1218
1219 methodDataHandle trap_mdo
1220 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1221
1222 // Print a bunch of diagnostics, if requested.
1223 if (TraceDeoptimization || LogCompilation) {
1224 ResourceMark rm;
1225 ttyLocker ttyl;
1226 char buf[100];
1227 if (xtty != NULL) {
1228 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1229 os::current_thread_id(),
1230 format_trap_request(buf, sizeof(buf), trap_request));
1231 nm->log_identity(xtty);
1232 }
1233 symbolHandle class_name;
1234 bool unresolved = false;
1235 if (unloaded_class_index >= 0) {
1236 constantPoolHandle constants (THREAD, trap_method->constants());
1237 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1238 class_name = symbolHandle(THREAD,
1239 constants->klass_name_at(unloaded_class_index));
1240 unresolved = true;
1241 if (xtty != NULL)
1242 xtty->print(" unresolved='1'");
1243 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1244 class_name = symbolHandle(THREAD,
1245 constants->symbol_at(unloaded_class_index));
1246 }
1247 if (xtty != NULL)
1248 xtty->name(class_name);
1249 }
1250 if (xtty != NULL && trap_mdo.not_null()) {
1251 // Dump the relevant MDO state.
1252 // This is the deopt count for the current reason, any previous
1253 // reasons or recompiles seen at this point.
1254 int dcnt = trap_mdo->trap_count(reason);
1255 if (dcnt != 0)
1256 xtty->print(" count='%d'", dcnt);
1257 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1258 int dos = (pdata == NULL)? 0: pdata->trap_state();
1259 if (dos != 0) {
1260 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1261 if (trap_state_is_recompiled(dos)) {
1262 int recnt2 = trap_mdo->overflow_recompile_count();
1263 if (recnt2 != 0)
1264 xtty->print(" recompiles2='%d'", recnt2);
1265 }
1266 }
1267 }
1268 if (xtty != NULL) {
1269 xtty->stamp();
1270 xtty->end_head();
1271 }
1272 if (TraceDeoptimization) { // make noise on the tty
1273 tty->print("Uncommon trap occurred in");
1274 nm->method()->print_short_name(tty);
1275 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1276 fr.pc(),
1277 (int) os::current_thread_id(),
1278 trap_reason_name(reason),
1279 trap_action_name(action),
1280 unloaded_class_index);
1281 if (class_name.not_null()) {
1282 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1283 class_name->print_symbol_on(tty);
1284 }
1285 tty->cr();
1286 }
1287 if (xtty != NULL) {
1288 // Log the precise location of the trap.
1289 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1290 xtty->begin_elem("jvms bci='%d'", sd->bci());
1291 xtty->method(sd->method());
1292 xtty->end_elem();
1293 if (sd->is_top()) break;
1294 }
1295 xtty->tail("uncommon_trap");
1296 }
1297 }
1298 // (End diagnostic printout.)
1299
1300 // Load class if necessary
1301 if (unloaded_class_index >= 0) {
1302 constantPoolHandle constants(THREAD, trap_method->constants());
1303 load_class_by_index(constants, unloaded_class_index);
1304 }
1305
1306 // Flush the nmethod if necessary and desirable.
1307 //
1308 // We need to avoid situations where we are re-flushing the nmethod
1309 // because of a hot deoptimization site. Repeated flushes at the same
1310 // point need to be detected by the compiler and avoided. If the compiler
1311 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1312 // module must take measures to avoid an infinite cycle of recompilation
1313 // and deoptimization. There are several such measures:
1314 //
1315 // 1. If a recompilation is ordered a second time at some site X
1316 // and for the same reason R, the action is adjusted to 'reinterpret',
1317 // to give the interpreter time to exercise the method more thoroughly.
1318 // If this happens, the method's overflow_recompile_count is incremented.
1319 //
1320 // 2. If the compiler fails to reduce the deoptimization rate, then
1321 // the method's overflow_recompile_count will begin to exceed the set
1322 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1323 // is adjusted to 'make_not_compilable', and the method is abandoned
1324 // to the interpreter. This is a performance hit for hot methods,
1325 // but is better than a disastrous infinite cycle of recompilations.
1326 // (Actually, only the method containing the site X is abandoned.)
1327 //
1328 // 3. In parallel with the previous measures, if the total number of
1329 // recompilations of a method exceeds the much larger set limit
1330 // PerMethodRecompilationCutoff, the method is abandoned.
1331 // This should only happen if the method is very large and has
1332 // many "lukewarm" deoptimizations. The code which enforces this
1333 // limit is elsewhere (class nmethod, class methodOopDesc).
1334 //
1335 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1336 // to recompile at each bytecode independently of the per-BCI cutoff.
1337 //
1338 // The decision to update code is up to the compiler, and is encoded
1339 // in the Action_xxx code. If the compiler requests Action_none
1340 // no trap state is changed, no compiled code is changed, and the
1341 // computation suffers along in the interpreter.
1342 //
1343 // The other action codes specify various tactics for decompilation
1344 // and recompilation. Action_maybe_recompile is the loosest, and
1345 // allows the compiled code to stay around until enough traps are seen,
1346 // and until the compiler gets around to recompiling the trapping method.
1347 //
1348 // The other actions cause immediate removal of the present code.
1349
1350 bool update_trap_state = true;
1351 bool make_not_entrant = false;
1352 bool make_not_compilable = false;
1353 bool reprofile = false;
1354 switch (action) {
1355 case Action_none:
1356 // Keep the old code.
1357 update_trap_state = false;
1358 break;
1359 case Action_maybe_recompile:
1360 // Do not need to invalidate the present code, but we can
1361 // initiate another
1362 // Start compiler without (necessarily) invalidating the nmethod.
1363 // The system will tolerate the old code, but new code should be
1364 // generated when possible.
1365 break;
1366 case Action_reinterpret:
1367 // Go back into the interpreter for a while, and then consider
1368 // recompiling form scratch.
1369 make_not_entrant = true;
1370 // Reset invocation counter for outer most method.
1371 // This will allow the interpreter to exercise the bytecodes
1372 // for a while before recompiling.
1373 // By contrast, Action_make_not_entrant is immediate.
1374 //
1375 // Note that the compiler will track null_check, null_assert,
1376 // range_check, and class_check events and log them as if they
1377 // had been traps taken from compiled code. This will update
1378 // the MDO trap history so that the next compilation will
1379 // properly detect hot trap sites.
1380 reprofile = true;
1381 break;
1382 case Action_make_not_entrant:
1383 // Request immediate recompilation, and get rid of the old code.
1384 // Make them not entrant, so next time they are called they get
1385 // recompiled. Unloaded classes are loaded now so recompile before next
1386 // time they are called. Same for uninitialized. The interpreter will
1387 // link the missing class, if any.
1388 make_not_entrant = true;
1389 break;
1390 case Action_make_not_compilable:
1391 // Give up on compiling this method at all.
1392 make_not_entrant = true;
1393 make_not_compilable = true;
1394 break;
1395 default:
1396 ShouldNotReachHere();
1397 }
1398
1399 // Setting +ProfileTraps fixes the following, on all platforms:
1400 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1401 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1402 // recompile relies on a methodDataOop to record heroic opt failures.
1403
1404 // Whether the interpreter is producing MDO data or not, we also need
1405 // to use the MDO to detect hot deoptimization points and control
1406 // aggressive optimization.
1407 bool inc_recompile_count = false;
1408 ProfileData* pdata = NULL;
1409 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1410 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1411 uint this_trap_count = 0;
1412 bool maybe_prior_trap = false;
1413 bool maybe_prior_recompile = false;
1414 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1415 //outputs:
1416 this_trap_count,
1417 maybe_prior_trap,
1418 maybe_prior_recompile);
1419 // Because the interpreter also counts null, div0, range, and class
1420 // checks, these traps from compiled code are double-counted.
1421 // This is harmless; it just means that the PerXTrapLimit values
1422 // are in effect a little smaller than they look.
1423
1424 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1425 if (per_bc_reason != Reason_none) {
1426 // Now take action based on the partially known per-BCI history.
1427 if (maybe_prior_trap
1428 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1429 // If there are too many traps at this BCI, force a recompile.
1430 // This will allow the compiler to see the limit overflow, and
1431 // take corrective action, if possible. The compiler generally
1432 // does not use the exact PerBytecodeTrapLimit value, but instead
1433 // changes its tactics if it sees any traps at all. This provides
1434 // a little hysteresis, delaying a recompile until a trap happens
1435 // several times.
1436 //
1437 // Actually, since there is only one bit of counter per BCI,
1438 // the possible per-BCI counts are {0,1,(per-method count)}.
1439 // This produces accurate results if in fact there is only
1440 // one hot trap site, but begins to get fuzzy if there are
1441 // many sites. For example, if there are ten sites each
1442 // trapping two or more times, they each get the blame for
1443 // all of their traps.
1444 make_not_entrant = true;
1445 }
1446
1447 // Detect repeated recompilation at the same BCI, and enforce a limit.
1448 if (make_not_entrant && maybe_prior_recompile) {
1449 // More than one recompile at this point.
1450 inc_recompile_count = maybe_prior_trap;
1451 }
1452 } else {
1453 // For reasons which are not recorded per-bytecode, we simply
1454 // force recompiles unconditionally.
1455 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1456 make_not_entrant = true;
1457 }
1458
1459 // Go back to the compiler if there are too many traps in this method.
1460 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1461 // If there are too many traps in this method, force a recompile.
1462 // This will allow the compiler to see the limit overflow, and
1463 // take corrective action, if possible.
1464 // (This condition is an unlikely backstop only, because the
1465 // PerBytecodeTrapLimit is more likely to take effect first,
1466 // if it is applicable.)
1467 make_not_entrant = true;
1468 }
1469
1470 // Here's more hysteresis: If there has been a recompile at
1471 // this trap point already, run the method in the interpreter
1472 // for a while to exercise it more thoroughly.
1473 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1474 reprofile = true;
1475 }
1476
1477 }
1478
1479 // Take requested actions on the method:
1480
1481 // Recompile
1482 if (make_not_entrant) {
1483 if (!nm->make_not_entrant()) {
1484 return; // the call did not change nmethod's state
1485 }
1486
1487 if (pdata != NULL) {
1488 // Record the recompilation event, if any.
1489 int tstate0 = pdata->trap_state();
1490 int tstate1 = trap_state_set_recompiled(tstate0, true);
1491 if (tstate1 != tstate0)
1492 pdata->set_trap_state(tstate1);
1493 }
1494 }
1495
1496 if (inc_recompile_count) {
1497 trap_mdo->inc_overflow_recompile_count();
1498 if ((uint)trap_mdo->overflow_recompile_count() >
1499 (uint)PerBytecodeRecompilationCutoff) {
1500 // Give up on the method containing the bad BCI.
1501 if (trap_method() == nm->method()) {
1502 make_not_compilable = true;
1503 } else {
1504 trap_method->set_not_compilable(CompLevel_full_optimization);
1505 // But give grace to the enclosing nm->method().
1506 }
1507 }
1508 }
1509
1510 // Reprofile
1511 if (reprofile) {
1512 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1513 }
1514
1515 // Give up compiling
1516 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1517 assert(make_not_entrant, "consistent");
1518 nm->method()->set_not_compilable(CompLevel_full_optimization);
1519 }
1520
1521 } // Free marked resources
1522
1523 }
1524 JRT_END
1525
1526 methodDataOop
1527 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1528 bool create_if_missing) {
1529 Thread* THREAD = thread;
1530 methodDataOop mdo = m()->method_data();
1531 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1532 // Build an MDO. Ignore errors like OutOfMemory;
1533 // that simply means we won't have an MDO to update.
1534 methodOopDesc::build_interpreter_method_data(m, THREAD);
1535 if (HAS_PENDING_EXCEPTION) {
1536 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1537 CLEAR_PENDING_EXCEPTION;
1538 }
1539 mdo = m()->method_data();
1540 }
1541 return mdo;
1542 }
1543
1544 ProfileData*
1545 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1546 int trap_bci,
1547 Deoptimization::DeoptReason reason,
1548 //outputs:
1549 uint& ret_this_trap_count,
1550 bool& ret_maybe_prior_trap,
1551 bool& ret_maybe_prior_recompile) {
1552 uint prior_trap_count = trap_mdo->trap_count(reason);
1553 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1554
1555 // If the runtime cannot find a place to store trap history,
1556 // it is estimated based on the general condition of the method.
1557 // If the method has ever been recompiled, or has ever incurred
1558 // a trap with the present reason , then this BCI is assumed
1559 // (pessimistically) to be the culprit.
1560 bool maybe_prior_trap = (prior_trap_count != 0);
1561 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1562 ProfileData* pdata = NULL;
1563
1564
1565 // For reasons which are recorded per bytecode, we check per-BCI data.
1566 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1567 if (per_bc_reason != Reason_none) {
1568 // Find the profile data for this BCI. If there isn't one,
1569 // try to allocate one from the MDO's set of spares.
1570 // This will let us detect a repeated trap at this point.
1571 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1572
1573 if (pdata != NULL) {
1574 // Query the trap state of this profile datum.
1575 int tstate0 = pdata->trap_state();
1576 if (!trap_state_has_reason(tstate0, per_bc_reason))
1577 maybe_prior_trap = false;
1578 if (!trap_state_is_recompiled(tstate0))
1579 maybe_prior_recompile = false;
1580
1581 // Update the trap state of this profile datum.
1582 int tstate1 = tstate0;
1583 // Record the reason.
1584 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1585 // Store the updated state on the MDO, for next time.
1586 if (tstate1 != tstate0)
1587 pdata->set_trap_state(tstate1);
1588 } else {
1589 if (LogCompilation && xtty != NULL) {
1590 ttyLocker ttyl;
1591 // Missing MDP? Leave a small complaint in the log.
1592 xtty->elem("missing_mdp bci='%d'", trap_bci);
1593 }
1594 }
1595 }
1596
1597 // Return results:
1598 ret_this_trap_count = this_trap_count;
1599 ret_maybe_prior_trap = maybe_prior_trap;
1600 ret_maybe_prior_recompile = maybe_prior_recompile;
1601 return pdata;
1602 }
1603
1604 void
1605 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1606 ResourceMark rm;
1607 // Ignored outputs:
1608 uint ignore_this_trap_count;
1609 bool ignore_maybe_prior_trap;
1610 bool ignore_maybe_prior_recompile;
1611 query_update_method_data(trap_mdo, trap_bci,
1612 (DeoptReason)reason,
1613 ignore_this_trap_count,
1614 ignore_maybe_prior_trap,
1615 ignore_maybe_prior_recompile);
1616 }
1617
1618 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1619
1620 // Still in Java no safepoints
1621 {
1622 // This enters VM and may safepoint
1623 uncommon_trap_inner(thread, trap_request);
1624 }
1625 return fetch_unroll_info_helper(thread);
1626 }
1627
1628 // Local derived constants.
1629 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1630 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1631 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1632
1633 //---------------------------trap_state_reason---------------------------------
1634 Deoptimization::DeoptReason
1635 Deoptimization::trap_state_reason(int trap_state) {
1636 // This assert provides the link between the width of DataLayout::trap_bits
1637 // and the encoding of "recorded" reasons. It ensures there are enough
1638 // bits to store all needed reasons in the per-BCI MDO profile.
1639 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1640 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1641 trap_state -= recompile_bit;
1642 if (trap_state == DS_REASON_MASK) {
1643 return Reason_many;
1644 } else {
1645 assert((int)Reason_none == 0, "state=0 => Reason_none");
1646 return (DeoptReason)trap_state;
1647 }
1648 }
1649 //-------------------------trap_state_has_reason-------------------------------
1650 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1651 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1652 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1653 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1654 trap_state -= recompile_bit;
1655 if (trap_state == DS_REASON_MASK) {
1656 return -1; // true, unspecifically (bottom of state lattice)
1657 } else if (trap_state == reason) {
1658 return 1; // true, definitely
1659 } else if (trap_state == 0) {
1660 return 0; // false, definitely (top of state lattice)
1661 } else {
1662 return 0; // false, definitely
1663 }
1664 }
1665 //-------------------------trap_state_add_reason-------------------------------
1666 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1667 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1668 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1669 trap_state -= recompile_bit;
1670 if (trap_state == DS_REASON_MASK) {
1671 return trap_state + recompile_bit; // already at state lattice bottom
1672 } else if (trap_state == reason) {
1673 return trap_state + recompile_bit; // the condition is already true
1674 } else if (trap_state == 0) {
1675 return reason + recompile_bit; // no condition has yet been true
1676 } else {
1677 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1678 }
1679 }
1680 //-----------------------trap_state_is_recompiled------------------------------
1681 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1682 return (trap_state & DS_RECOMPILE_BIT) != 0;
1683 }
1684 //-----------------------trap_state_set_recompiled-----------------------------
1685 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1686 if (z) return trap_state | DS_RECOMPILE_BIT;
1687 else return trap_state & ~DS_RECOMPILE_BIT;
1688 }
1689 //---------------------------format_trap_state---------------------------------
1690 // This is used for debugging and diagnostics, including hotspot.log output.
1691 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1692 int trap_state) {
1693 DeoptReason reason = trap_state_reason(trap_state);
1694 bool recomp_flag = trap_state_is_recompiled(trap_state);
1695 // Re-encode the state from its decoded components.
1696 int decoded_state = 0;
1697 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1698 decoded_state = trap_state_add_reason(decoded_state, reason);
1699 if (recomp_flag)
1700 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1701 // If the state re-encodes properly, format it symbolically.
1702 // Because this routine is used for debugging and diagnostics,
1703 // be robust even if the state is a strange value.
1704 size_t len;
1705 if (decoded_state != trap_state) {
1706 // Random buggy state that doesn't decode??
1707 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1708 } else {
1709 len = jio_snprintf(buf, buflen, "%s%s",
1710 trap_reason_name(reason),
1711 recomp_flag ? " recompiled" : "");
1712 }
1713 if (len >= buflen)
1714 buf[buflen-1] = '\0';
1715 return buf;
1716 }
1717
1718
1719 //--------------------------------statics--------------------------------------
1720 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1721 = Deoptimization::Action_reinterpret;
1722 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1723 // Note: Keep this in sync. with enum DeoptReason.
1724 "none",
1725 "null_check",
1726 "null_assert",
1727 "range_check",
1728 "class_check",
1729 "array_check",
1730 "intrinsic",
1731 "bimorphic",
1732 "unloaded",
1733 "uninitialized",
1734 "unreached",
1735 "unhandled",
1736 "constraint",
1737 "div0_check",
1738 "age",
1739 "predicate"
1740 };
1741 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1742 // Note: Keep this in sync. with enum DeoptAction.
1743 "none",
1744 "maybe_recompile",
1745 "reinterpret",
1746 "make_not_entrant",
1747 "make_not_compilable"
1748 };
1749
1750 const char* Deoptimization::trap_reason_name(int reason) {
1751 if (reason == Reason_many) return "many";
1752 if ((uint)reason < Reason_LIMIT)
1753 return _trap_reason_name[reason];
1754 static char buf[20];
1755 sprintf(buf, "reason%d", reason);
1756 return buf;
1757 }
1758 const char* Deoptimization::trap_action_name(int action) {
1759 if ((uint)action < Action_LIMIT)
1760 return _trap_action_name[action];
1761 static char buf[20];
1762 sprintf(buf, "action%d", action);
1763 return buf;
1764 }
1765
1766 // This is used for debugging and diagnostics, including hotspot.log output.
1767 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1768 int trap_request) {
1769 jint unloaded_class_index = trap_request_index(trap_request);
1770 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1771 const char* action = trap_action_name(trap_request_action(trap_request));
1772 size_t len;
1773 if (unloaded_class_index < 0) {
1774 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1775 reason, action);
1776 } else {
1777 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1778 reason, action, unloaded_class_index);
1779 }
1780 if (len >= buflen)
1781 buf[buflen-1] = '\0';
1782 return buf;
1783 }
1784
1785 juint Deoptimization::_deoptimization_hist
1786 [Deoptimization::Reason_LIMIT]
1787 [1 + Deoptimization::Action_LIMIT]
1788 [Deoptimization::BC_CASE_LIMIT]
1789 = {0};
1790
1791 enum {
1792 LSB_BITS = 8,
1793 LSB_MASK = right_n_bits(LSB_BITS)
1794 };
1795
1796 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1797 Bytecodes::Code bc) {
1798 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1799 assert(action >= 0 && action < Action_LIMIT, "oob");
1800 _deoptimization_hist[Reason_none][0][0] += 1; // total
1801 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1802 juint* cases = _deoptimization_hist[reason][1+action];
1803 juint* bc_counter_addr = NULL;
1804 juint bc_counter = 0;
1805 // Look for an unused counter, or an exact match to this BC.
1806 if (bc != Bytecodes::_illegal) {
1807 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1808 juint* counter_addr = &cases[bc_case];
1809 juint counter = *counter_addr;
1810 if ((counter == 0 && bc_counter_addr == NULL)
1811 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1812 // this counter is either free or is already devoted to this BC
1813 bc_counter_addr = counter_addr;
1814 bc_counter = counter | bc;
1815 }
1816 }
1817 }
1818 if (bc_counter_addr == NULL) {
1819 // Overflow, or no given bytecode.
1820 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1821 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1822 }
1823 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1824 }
1825
1826 jint Deoptimization::total_deoptimization_count() {
1827 return _deoptimization_hist[Reason_none][0][0];
1828 }
1829
1830 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1831 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1832 return _deoptimization_hist[reason][0][0];
1833 }
1834
1835 void Deoptimization::print_statistics() {
1836 juint total = total_deoptimization_count();
1837 juint account = total;
1838 if (total != 0) {
1839 ttyLocker ttyl;
1840 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1841 tty->print_cr("Deoptimization traps recorded:");
1842 #define PRINT_STAT_LINE(name, r) \
1843 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1844 PRINT_STAT_LINE("total", total);
1845 // For each non-zero entry in the histogram, print the reason,
1846 // the action, and (if specifically known) the type of bytecode.
1847 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1848 for (int action = 0; action < Action_LIMIT; action++) {
1849 juint* cases = _deoptimization_hist[reason][1+action];
1850 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1851 juint counter = cases[bc_case];
1852 if (counter != 0) {
1853 char name[1*K];
1854 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1855 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1856 bc = Bytecodes::_illegal;
1857 sprintf(name, "%s/%s/%s",
1858 trap_reason_name(reason),
1859 trap_action_name(action),
1860 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1861 juint r = counter >> LSB_BITS;
1862 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1863 account -= r;
1864 }
1865 }
1866 }
1867 }
1868 if (account != 0) {
1869 PRINT_STAT_LINE("unaccounted", account);
1870 }
1871 #undef PRINT_STAT_LINE
1872 if (xtty != NULL) xtty->tail("statistics");
1873 }
1874 }
1875 #else // COMPILER2 || SHARK
1876
1877
1878 // Stubs for C1 only system.
1879 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1880 return false;
1881 }
1882
1883 const char* Deoptimization::trap_reason_name(int reason) {
1884 return "unknown";
1885 }
1886
1887 void Deoptimization::print_statistics() {
1888 // no output
1889 }
1890
1891 void
1892 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1893 // no udpate
1894 }
1895
1896 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1897 return 0;
1898 }
1899
1900 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1901 Bytecodes::Code bc) {
1902 // no update
1903 }
1904
1905 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1906 int trap_state) {
1907 jio_snprintf(buf, buflen, "#%d", trap_state);
1908 return buf;
1909 }
1910
1911 #endif // COMPILER2 || SHARK