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 // Set the deoptee nmethod
177 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
178 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
179
180 // Create a growable array of VFrames where each VFrame represents an inlined
181 // Java frame. This storage is allocated with the usual system arena.
182 assert(deoptee.is_compiled_frame(), "Wrong frame type");
183 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
184 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
185 while (!vf->is_top()) {
186 assert(vf->is_compiled_frame(), "Wrong frame type");
187 chunk->push(compiledVFrame::cast(vf));
188 vf = vf->sender();
189 }
190 assert(vf->is_compiled_frame(), "Wrong frame type");
191 chunk->push(compiledVFrame::cast(vf));
192
193 #ifdef COMPILER2
194 // Reallocate the non-escaping objects and restore their fields. Then
195 // relock objects if synchronization on them was eliminated.
196 if (DoEscapeAnalysis) {
197 if (EliminateAllocations) {
198 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
199 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
200
201 // The flag return_oop() indicates call sites which return oop
202 // in compiled code. Such sites include java method calls,
203 // runtime calls (for example, used to allocate new objects/arrays
204 // on slow code path) and any other calls generated in compiled code.
205 // It is not guaranteed that we can get such information here only
206 // by analyzing bytecode in deoptimized frames. This is why this flag
207 // is set during method compilation (see Compile::Process_OopMap_Node()).
208 bool save_oop_result = chunk->at(0)->scope()->return_oop();
209 Handle return_value;
210 if (save_oop_result) {
211 // Reallocation may trigger GC. If deoptimization happened on return from
212 // call which returns oop we need to save it since it is not in oopmap.
213 oop result = deoptee.saved_oop_result(&map);
214 assert(result == NULL || result->is_oop(), "must be oop");
215 return_value = Handle(thread, result);
216 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
217 if (TraceDeoptimization) {
218 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
219 }
220 }
221 bool reallocated = false;
222 if (objects != NULL) {
223 JRT_BLOCK
224 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
225 JRT_END
226 }
227 if (reallocated) {
228 reassign_fields(&deoptee, &map, objects);
229 #ifndef PRODUCT
230 if (TraceDeoptimization) {
231 ttyLocker ttyl;
232 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
233 print_objects(objects);
234 }
235 #endif
236 }
237 if (save_oop_result) {
238 // Restore result.
239 deoptee.set_saved_oop_result(&map, return_value());
240 }
241 }
242 if (EliminateLocks) {
243 #ifndef PRODUCT
244 bool first = true;
245 #endif
246 for (int i = 0; i < chunk->length(); i++) {
247 compiledVFrame* cvf = chunk->at(i);
248 assert (cvf->scope() != NULL,"expect only compiled java frames");
249 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
250 if (monitors->is_nonempty()) {
251 relock_objects(monitors, thread);
252 #ifndef PRODUCT
253 if (TraceDeoptimization) {
254 ttyLocker ttyl;
255 for (int j = 0; j < monitors->length(); j++) {
256 MonitorInfo* mi = monitors->at(j);
257 if (mi->eliminated()) {
258 if (first) {
259 first = false;
260 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
261 }
262 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
263 }
264 }
265 }
266 #endif
267 }
268 }
269 }
270 }
271 #endif // COMPILER2
272 // Ensure that no safepoint is taken after pointers have been stored
273 // in fields of rematerialized objects. If a safepoint occurs from here on
274 // out the java state residing in the vframeArray will be missed.
275 No_Safepoint_Verifier no_safepoint;
276
277 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
278
279 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
280 thread->set_vframe_array_head(array);
281
282 // Now that the vframeArray has been created if we have any deferred local writes
283 // added by jvmti then we can free up that structure as the data is now in the
284 // vframeArray
285
286 if (thread->deferred_locals() != NULL) {
287 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
288 int i = 0;
289 do {
290 // Because of inlining we could have multiple vframes for a single frame
291 // and several of the vframes could have deferred writes. Find them all.
292 if (list->at(i)->id() == array->original().id()) {
293 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
294 list->remove_at(i);
295 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
296 delete dlv;
297 } else {
298 i++;
299 }
300 } while ( i < list->length() );
301 if (list->length() == 0) {
302 thread->set_deferred_locals(NULL);
303 // free the list and elements back to C heap.
304 delete list;
305 }
306
307 }
308
309 #ifndef SHARK
310 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
311 CodeBlob* cb = stub_frame.cb();
312 // Verify we have the right vframeArray
313 assert(cb->frame_size() >= 0, "Unexpected frame size");
314 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
315
316 // If the deopt call site is a MethodHandle invoke call site we have
317 // to adjust the unpack_sp.
318 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
319 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
320 unpack_sp = deoptee.unextended_sp();
321
322 #ifdef ASSERT
323 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
324 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
325 #endif
326 #else
327 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
328 #endif // !SHARK
329
330 // This is a guarantee instead of an assert because if vframe doesn't match
331 // we will unpack the wrong deoptimized frame and wind up in strange places
332 // where it will be very difficult to figure out what went wrong. Better
333 // to die an early death here than some very obscure death later when the
334 // trail is cold.
335 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
336 // in that it will fail to detect a problem when there is one. This needs
337 // more work in tiger timeframe.
338 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
339
340 int number_of_frames = array->frames();
341
342 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
343 // virtual activation, which is the reverse of the elements in the vframes array.
344 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
345 // +1 because we always have an interpreter return address for the final slot.
346 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
347 int callee_parameters = 0;
348 int callee_locals = 0;
349 int popframe_extra_args = 0;
350 // Create an interpreter return address for the stub to use as its return
351 // address so the skeletal frames are perfectly walkable
352 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
353
354 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
355 // activation be put back on the expression stack of the caller for reexecution
356 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
357 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
358 }
359
360 //
361 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
362 // frame_sizes/frame_pcs[1] next oldest frame (int)
363 // frame_sizes/frame_pcs[n] youngest frame (int)
364 //
365 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
366 // owns the space for the return address to it's caller). Confusing ain't it.
367 //
368 // The vframe array can address vframes with indices running from
369 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
370 // When we create the skeletal frames we need the oldest frame to be in the zero slot
371 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
372 // so things look a little strange in this loop.
373 //
374 for (int index = 0; index < array->frames(); index++ ) {
375 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
376 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
377 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
378 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
379 callee_locals,
380 index == 0,
381 popframe_extra_args);
382 // This pc doesn't have to be perfect just good enough to identify the frame
383 // as interpreted so the skeleton frame will be walkable
384 // The correct pc will be set when the skeleton frame is completely filled out
385 // The final pc we store in the loop is wrong and will be overwritten below
386 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
387
388 callee_parameters = array->element(index)->method()->size_of_parameters();
389 callee_locals = array->element(index)->method()->max_locals();
390 popframe_extra_args = 0;
391 }
392
393 // Compute whether the root vframe returns a float or double value.
394 BasicType return_type;
395 {
396 HandleMark hm;
397 methodHandle method(thread, array->element(0)->method());
398 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci());
399 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL;
400 }
401
402 // Compute information for handling adapters and adjusting the frame size of the caller.
403 int caller_adjustment = 0;
404
405 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
406 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
407 // than simply use array->sender.pc(). This requires us to walk the current set of frames
408 //
409 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
410 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
411
412 // Compute the amount the oldest interpreter frame will have to adjust
413 // its caller's stack by. If the caller is a compiled frame then
414 // we pretend that the callee has no parameters so that the
415 // extension counts for the full amount of locals and not just
416 // locals-parms. This is because without a c2i adapter the parm
417 // area as created by the compiled frame will not be usable by
418 // the interpreter. (Depending on the calling convention there
419 // may not even be enough space).
420
421 // QQQ I'd rather see this pushed down into last_frame_adjust
422 // and have it take the sender (aka caller).
423
424 if (deopt_sender.is_compiled_frame()) {
425 caller_adjustment = last_frame_adjust(0, callee_locals);
426 } else if (callee_locals > callee_parameters) {
427 // The caller frame may need extending to accommodate
428 // non-parameter locals of the first unpacked interpreted frame.
429 // Compute that adjustment.
430 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
431 }
432
433
434 // If the sender is deoptimized the we must retrieve the address of the handler
435 // since the frame will "magically" show the original pc before the deopt
436 // and we'd undo the deopt.
437
438 frame_pcs[0] = deopt_sender.raw_pc();
439
440 #ifndef SHARK
441 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
442 #endif // SHARK
443
444 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
445 caller_adjustment * BytesPerWord,
446 number_of_frames,
447 frame_sizes,
448 frame_pcs,
449 return_type);
450 #if defined(IA32) || defined(AMD64)
451 // We need a way to pass fp to the unpacking code so the skeletal frames
452 // come out correct. This is only needed for x86 because of c2 using ebp
453 // as an allocatable register. So this update is useless (and harmless)
454 // on the other platforms. It would be nice to do this in a different
455 // way but even the old style deoptimization had a problem with deriving
456 // this value. NEEDS_CLEANUP
457 // Note: now that c1 is using c2's deopt blob we must do this on all
458 // x86 based platforms
459 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
460 *fp_addr = array->sender().fp(); // was adapter_caller
461 #endif /* IA32 || AMD64 */
462
463 if (array->frames() > 1) {
464 if (VerifyStack && TraceDeoptimization) {
465 tty->print_cr("Deoptimizing method containing inlining");
466 }
467 }
468
469 array->set_unroll_block(info);
470 return info;
471 }
472
473 // Called to cleanup deoptimization data structures in normal case
474 // after unpacking to stack and when stack overflow error occurs
475 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
476 vframeArray *array) {
477
478 // Get array if coming from exception
479 if (array == NULL) {
480 array = thread->vframe_array_head();
481 }
482 thread->set_vframe_array_head(NULL);
483
484 // Free the previous UnrollBlock
485 vframeArray* old_array = thread->vframe_array_last();
486 thread->set_vframe_array_last(array);
487
488 if (old_array != NULL) {
489 UnrollBlock* old_info = old_array->unroll_block();
490 old_array->set_unroll_block(NULL);
491 delete old_info;
492 delete old_array;
493 }
494
495 // Deallocate any resource creating in this routine and any ResourceObjs allocated
496 // inside the vframeArray (StackValueCollections)
497
498 delete thread->deopt_mark();
499 thread->set_deopt_mark(NULL);
500 thread->set_deopt_nmethod(NULL);
501
502
503 if (JvmtiExport::can_pop_frame()) {
504 #ifndef CC_INTERP
505 // Regardless of whether we entered this routine with the pending
506 // popframe condition bit set, we should always clear it now
507 thread->clear_popframe_condition();
508 #else
509 // C++ interpeter will clear has_pending_popframe when it enters
510 // with method_resume. For deopt_resume2 we clear it now.
511 if (thread->popframe_forcing_deopt_reexecution())
512 thread->clear_popframe_condition();
513 #endif /* CC_INTERP */
514 }
515
516 // unpack_frames() is called at the end of the deoptimization handler
517 // and (in C2) at the end of the uncommon trap handler. Note this fact
518 // so that an asynchronous stack walker can work again. This counter is
519 // incremented at the beginning of fetch_unroll_info() and (in C2) at
520 // the beginning of uncommon_trap().
521 thread->dec_in_deopt_handler();
522 }
523
524
525 // Return BasicType of value being returned
526 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
527
528 // We are already active int he special DeoptResourceMark any ResourceObj's we
529 // allocate will be freed at the end of the routine.
530
531 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
532 // but makes the entry a little slower. There is however a little dance we have to
533 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
534 ResetNoHandleMark rnhm; // No-op in release/product versions
535 HandleMark hm;
536
537 frame stub_frame = thread->last_frame();
538
539 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
540 // must point to the vframeArray for the unpack frame.
541 vframeArray* array = thread->vframe_array_head();
542
543 #ifndef PRODUCT
544 if (TraceDeoptimization) {
545 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
546 }
547 #endif
548
549 UnrollBlock* info = array->unroll_block();
550
551 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
552 array->unpack_to_stack(stub_frame, exec_mode);
553
554 BasicType bt = info->return_type();
555
556 // If we have an exception pending, claim that the return type is an oop
557 // so the deopt_blob does not overwrite the exception_oop.
558
559 if (exec_mode == Unpack_exception)
560 bt = T_OBJECT;
561
562 // Cleanup thread deopt data
563 cleanup_deopt_info(thread, array);
564
565 #ifndef PRODUCT
566 if (VerifyStack) {
567 ResourceMark res_mark;
568
569 // Verify that the just-unpacked frames match the interpreter's
570 // notions of expression stack and locals
571 vframeArray* cur_array = thread->vframe_array_last();
572 RegisterMap rm(thread, false);
573 rm.set_include_argument_oops(false);
574 bool is_top_frame = true;
575 int callee_size_of_parameters = 0;
576 int callee_max_locals = 0;
577 for (int i = 0; i < cur_array->frames(); i++) {
578 vframeArrayElement* el = cur_array->element(i);
579 frame* iframe = el->iframe();
580 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
581
582 // Get the oop map for this bci
583 InterpreterOopMap mask;
584 int cur_invoke_parameter_size = 0;
585 bool try_next_mask = false;
586 int next_mask_expression_stack_size = -1;
587 int top_frame_expression_stack_adjustment = 0;
588 methodHandle mh(thread, iframe->interpreter_frame_method());
589 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
590 BytecodeStream str(mh);
591 str.set_start(iframe->interpreter_frame_bci());
592 int max_bci = mh->code_size();
593 // Get to the next bytecode if possible
594 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
595 // Check to see if we can grab the number of outgoing arguments
596 // at an uncommon trap for an invoke (where the compiler
597 // generates debug info before the invoke has executed)
598 Bytecodes::Code cur_code = str.next();
599 if (cur_code == Bytecodes::_invokevirtual ||
600 cur_code == Bytecodes::_invokespecial ||
601 cur_code == Bytecodes::_invokestatic ||
602 cur_code == Bytecodes::_invokeinterface) {
603 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci());
604 symbolHandle signature(thread, invoke->signature());
605 ArgumentSizeComputer asc(signature);
606 cur_invoke_parameter_size = asc.size();
607 if (cur_code != Bytecodes::_invokestatic) {
608 // Add in receiver
609 ++cur_invoke_parameter_size;
610 }
611 }
612 if (str.bci() < max_bci) {
613 Bytecodes::Code bc = str.next();
614 if (bc >= 0) {
615 // The interpreter oop map generator reports results before
616 // the current bytecode has executed except in the case of
617 // calls. It seems to be hard to tell whether the compiler
618 // has emitted debug information matching the "state before"
619 // a given bytecode or the state after, so we try both
620 switch (cur_code) {
621 case Bytecodes::_invokevirtual:
622 case Bytecodes::_invokespecial:
623 case Bytecodes::_invokestatic:
624 case Bytecodes::_invokeinterface:
625 case Bytecodes::_athrow:
626 break;
627 default: {
628 InterpreterOopMap next_mask;
629 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
630 next_mask_expression_stack_size = next_mask.expression_stack_size();
631 // Need to subtract off the size of the result type of
632 // the bytecode because this is not described in the
633 // debug info but returned to the interpreter in the TOS
634 // caching register
635 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
636 if (bytecode_result_type != T_ILLEGAL) {
637 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
638 }
639 assert(top_frame_expression_stack_adjustment >= 0, "");
640 try_next_mask = true;
641 break;
642 }
643 }
644 }
645 }
646
647 // Verify stack depth and oops in frame
648 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
649 if (!(
650 /* SPARC */
651 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
652 /* x86 */
653 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
654 (try_next_mask &&
655 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
656 top_frame_expression_stack_adjustment))) ||
657 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
658 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
659 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
660 )) {
661 ttyLocker ttyl;
662
663 // Print out some information that will help us debug the problem
664 tty->print_cr("Wrong number of expression stack elements during deoptimization");
665 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
666 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
667 iframe->interpreter_frame_expression_stack_size());
668 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
669 tty->print_cr(" try_next_mask = %d", try_next_mask);
670 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
671 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
672 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
673 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
674 tty->print_cr(" exec_mode = %d", exec_mode);
675 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
676 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
677 tty->print_cr(" Interpreted frames:");
678 for (int k = 0; k < cur_array->frames(); k++) {
679 vframeArrayElement* el = cur_array->element(k);
680 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
681 }
682 cur_array->print_on_2(tty);
683 guarantee(false, "wrong number of expression stack elements during deopt");
684 }
685 VerifyOopClosure verify;
686 iframe->oops_interpreted_do(&verify, &rm, false);
687 callee_size_of_parameters = mh->size_of_parameters();
688 callee_max_locals = mh->max_locals();
689 is_top_frame = false;
690 }
691 }
692 #endif /* !PRODUCT */
693
694
695 return bt;
696 JRT_END
697
698
699 int Deoptimization::deoptimize_dependents() {
700 Threads::deoptimized_wrt_marked_nmethods();
701 return 0;
702 }
703
704
705 #ifdef COMPILER2
706 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
707 Handle pending_exception(thread->pending_exception());
708 const char* exception_file = thread->exception_file();
709 int exception_line = thread->exception_line();
710 thread->clear_pending_exception();
711
712 for (int i = 0; i < objects->length(); i++) {
713 assert(objects->at(i)->is_object(), "invalid debug information");
714 ObjectValue* sv = (ObjectValue*) objects->at(i);
715
716 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
717 oop obj = NULL;
718
719 if (k->oop_is_instance()) {
720 instanceKlass* ik = instanceKlass::cast(k());
721 obj = ik->allocate_instance(CHECK_(false));
722 } else if (k->oop_is_typeArray()) {
723 typeArrayKlass* ak = typeArrayKlass::cast(k());
724 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
725 int len = sv->field_size() / type2size[ak->element_type()];
726 obj = ak->allocate(len, CHECK_(false));
727 } else if (k->oop_is_objArray()) {
728 objArrayKlass* ak = objArrayKlass::cast(k());
729 obj = ak->allocate(sv->field_size(), CHECK_(false));
730 }
731
732 assert(obj != NULL, "allocation failed");
733 assert(sv->value().is_null(), "redundant reallocation");
734 sv->set_value(obj);
735 }
736
737 if (pending_exception.not_null()) {
738 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
739 }
740
741 return true;
742 }
743
744 // This assumes that the fields are stored in ObjectValue in the same order
745 // they are yielded by do_nonstatic_fields.
746 class FieldReassigner: public FieldClosure {
747 frame* _fr;
748 RegisterMap* _reg_map;
749 ObjectValue* _sv;
750 instanceKlass* _ik;
751 oop _obj;
752
753 int _i;
754 public:
755 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
756 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
757
758 int i() const { return _i; }
759
760
761 void do_field(fieldDescriptor* fd) {
762 intptr_t val;
763 StackValue* value =
764 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
765 int offset = fd->offset();
766 switch (fd->field_type()) {
767 case T_OBJECT: case T_ARRAY:
768 assert(value->type() == T_OBJECT, "Agreement.");
769 _obj->obj_field_put(offset, value->get_obj()());
770 break;
771
772 case T_LONG: case T_DOUBLE: {
773 assert(value->type() == T_INT, "Agreement.");
774 StackValue* low =
775 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
776 #ifdef _LP64
777 jlong res = (jlong)low->get_int();
778 #else
779 #ifdef SPARC
780 // For SPARC we have to swap high and low words.
781 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
782 #else
783 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
784 #endif //SPARC
785 #endif
786 _obj->long_field_put(offset, res);
787 break;
788 }
789 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
790 case T_INT: case T_FLOAT: // 4 bytes.
791 assert(value->type() == T_INT, "Agreement.");
792 val = value->get_int();
793 _obj->int_field_put(offset, (jint)*((jint*)&val));
794 break;
795
796 case T_SHORT: case T_CHAR: // 2 bytes
797 assert(value->type() == T_INT, "Agreement.");
798 val = value->get_int();
799 _obj->short_field_put(offset, (jshort)*((jint*)&val));
800 break;
801
802 case T_BOOLEAN: case T_BYTE: // 1 byte
803 assert(value->type() == T_INT, "Agreement.");
804 val = value->get_int();
805 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
806 break;
807
808 default:
809 ShouldNotReachHere();
810 }
811 _i++;
812 }
813 };
814
815 // restore elements of an eliminated type array
816 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
817 int index = 0;
818 intptr_t val;
819
820 for (int i = 0; i < sv->field_size(); i++) {
821 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
822 switch(type) {
823 case T_LONG: case T_DOUBLE: {
824 assert(value->type() == T_INT, "Agreement.");
825 StackValue* low =
826 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
827 #ifdef _LP64
828 jlong res = (jlong)low->get_int();
829 #else
830 #ifdef SPARC
831 // For SPARC we have to swap high and low words.
832 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
833 #else
834 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
835 #endif //SPARC
836 #endif
837 obj->long_at_put(index, res);
838 break;
839 }
840
841 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
842 case T_INT: case T_FLOAT: // 4 bytes.
843 assert(value->type() == T_INT, "Agreement.");
844 val = value->get_int();
845 obj->int_at_put(index, (jint)*((jint*)&val));
846 break;
847
848 case T_SHORT: case T_CHAR: // 2 bytes
849 assert(value->type() == T_INT, "Agreement.");
850 val = value->get_int();
851 obj->short_at_put(index, (jshort)*((jint*)&val));
852 break;
853
854 case T_BOOLEAN: case T_BYTE: // 1 byte
855 assert(value->type() == T_INT, "Agreement.");
856 val = value->get_int();
857 obj->bool_at_put(index, (jboolean)*((jint*)&val));
858 break;
859
860 default:
861 ShouldNotReachHere();
862 }
863 index++;
864 }
865 }
866
867
868 // restore fields of an eliminated object array
869 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
870 for (int i = 0; i < sv->field_size(); i++) {
871 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
872 assert(value->type() == T_OBJECT, "object element expected");
873 obj->obj_at_put(i, value->get_obj()());
874 }
875 }
876
877
878 // restore fields of all eliminated objects and arrays
879 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
880 for (int i = 0; i < objects->length(); i++) {
881 ObjectValue* sv = (ObjectValue*) objects->at(i);
882 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
883 Handle obj = sv->value();
884 assert(obj.not_null(), "reallocation was missed");
885
886 if (k->oop_is_instance()) {
887 instanceKlass* ik = instanceKlass::cast(k());
888 FieldReassigner reassign(fr, reg_map, sv, obj());
889 ik->do_nonstatic_fields(&reassign);
890 } else if (k->oop_is_typeArray()) {
891 typeArrayKlass* ak = typeArrayKlass::cast(k());
892 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
893 } else if (k->oop_is_objArray()) {
894 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
895 }
896 }
897 }
898
899
900 // relock objects for which synchronization was eliminated
901 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
902 for (int i = 0; i < monitors->length(); i++) {
903 MonitorInfo* mon_info = monitors->at(i);
904 if (mon_info->eliminated()) {
905 assert(mon_info->owner() != NULL, "reallocation was missed");
906 Handle obj = Handle(mon_info->owner());
907 markOop mark = obj->mark();
908 if (UseBiasedLocking && mark->has_bias_pattern()) {
909 // New allocated objects may have the mark set to anonymously biased.
910 // Also the deoptimized method may called methods with synchronization
911 // where the thread-local object is bias locked to the current thread.
912 assert(mark->is_biased_anonymously() ||
913 mark->biased_locker() == thread, "should be locked to current thread");
914 // Reset mark word to unbiased prototype.
915 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
916 obj->set_mark(unbiased_prototype);
917 }
918 BasicLock* lock = mon_info->lock();
919 ObjectSynchronizer::slow_enter(obj, lock, thread);
920 }
921 assert(mon_info->owner()->is_locked(), "object must be locked now");
922 }
923 }
924
925
926 #ifndef PRODUCT
927 // print information about reallocated objects
928 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
929 fieldDescriptor fd;
930
931 for (int i = 0; i < objects->length(); i++) {
932 ObjectValue* sv = (ObjectValue*) objects->at(i);
933 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
934 Handle obj = sv->value();
935
936 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
937 k->as_klassOop()->print_value();
938 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
939 tty->cr();
940
941 if (Verbose) {
942 k->oop_print_on(obj(), tty);
943 }
944 }
945 }
946 #endif
947 #endif // COMPILER2
948
949 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
950
951 #ifndef PRODUCT
952 if (TraceDeoptimization) {
953 ttyLocker ttyl;
954 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
955 fr.print_on(tty);
956 tty->print_cr(" Virtual frames (innermost first):");
957 for (int index = 0; index < chunk->length(); index++) {
958 compiledVFrame* vf = chunk->at(index);
959 tty->print(" %2d - ", index);
960 vf->print_value();
961 int bci = chunk->at(index)->raw_bci();
962 const char* code_name;
963 if (bci == SynchronizationEntryBCI) {
964 code_name = "sync entry";
965 } else {
966 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci);
967 code_name = Bytecodes::name(code);
968 }
969 tty->print(" - %s", code_name);
970 tty->print_cr(" @ bci %d ", bci);
971 if (Verbose) {
972 vf->print();
973 tty->cr();
974 }
975 }
976 }
977 #endif
978
979 // Register map for next frame (used for stack crawl). We capture
980 // the state of the deopt'ing frame's caller. Thus if we need to
981 // stuff a C2I adapter we can properly fill in the callee-save
982 // register locations.
983 frame caller = fr.sender(reg_map);
984 int frame_size = caller.sp() - fr.sp();
985
986 frame sender = caller;
987
988 // Since the Java thread being deoptimized will eventually adjust it's own stack,
989 // the vframeArray containing the unpacking information is allocated in the C heap.
990 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
991 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
992
993 // Compare the vframeArray to the collected vframes
994 assert(array->structural_compare(thread, chunk), "just checking");
995 Events::log("# vframes = %d", (intptr_t)chunk->length());
996
997 #ifndef PRODUCT
998 if (TraceDeoptimization) {
999 ttyLocker ttyl;
1000 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1001 }
1002 #endif // PRODUCT
1003
1004 return array;
1005 }
1006
1007
1008 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1009 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1010 for (int i = 0; i < monitors->length(); i++) {
1011 MonitorInfo* mon_info = monitors->at(i);
1012 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1013 objects_to_revoke->append(Handle(mon_info->owner()));
1014 }
1015 }
1016 }
1017
1018
1019 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1020 if (!UseBiasedLocking) {
1021 return;
1022 }
1023
1024 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1025
1026 // Unfortunately we don't have a RegisterMap available in most of
1027 // the places we want to call this routine so we need to walk the
1028 // stack again to update the register map.
1029 if (map == NULL || !map->update_map()) {
1030 StackFrameStream sfs(thread, true);
1031 bool found = false;
1032 while (!found && !sfs.is_done()) {
1033 frame* cur = sfs.current();
1034 sfs.next();
1035 found = cur->id() == fr.id();
1036 }
1037 assert(found, "frame to be deoptimized not found on target thread's stack");
1038 map = sfs.register_map();
1039 }
1040
1041 vframe* vf = vframe::new_vframe(&fr, map, thread);
1042 compiledVFrame* cvf = compiledVFrame::cast(vf);
1043 // Revoke monitors' biases in all scopes
1044 while (!cvf->is_top()) {
1045 collect_monitors(cvf, objects_to_revoke);
1046 cvf = compiledVFrame::cast(cvf->sender());
1047 }
1048 collect_monitors(cvf, objects_to_revoke);
1049
1050 if (SafepointSynchronize::is_at_safepoint()) {
1051 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1052 } else {
1053 BiasedLocking::revoke(objects_to_revoke);
1054 }
1055 }
1056
1057
1058 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1059 if (!UseBiasedLocking) {
1060 return;
1061 }
1062
1063 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1064 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1065 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1066 if (jt->has_last_Java_frame()) {
1067 StackFrameStream sfs(jt, true);
1068 while (!sfs.is_done()) {
1069 frame* cur = sfs.current();
1070 if (cb->contains(cur->pc())) {
1071 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1072 compiledVFrame* cvf = compiledVFrame::cast(vf);
1073 // Revoke monitors' biases in all scopes
1074 while (!cvf->is_top()) {
1075 collect_monitors(cvf, objects_to_revoke);
1076 cvf = compiledVFrame::cast(cvf->sender());
1077 }
1078 collect_monitors(cvf, objects_to_revoke);
1079 }
1080 sfs.next();
1081 }
1082 }
1083 }
1084 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1085 }
1086
1087
1088 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1089 assert(fr.can_be_deoptimized(), "checking frame type");
1090
1091 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1092
1093 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1094
1095 // Patch the nmethod so that when execution returns to it we will
1096 // deopt the execution state and return to the interpreter.
1097 fr.deoptimize(thread);
1098 }
1099
1100 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1101 // Deoptimize only if the frame comes from compile code.
1102 // Do not deoptimize the frame which is already patched
1103 // during the execution of the loops below.
1104 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1105 return;
1106 }
1107 ResourceMark rm;
1108 DeoptimizationMarker dm;
1109 if (UseBiasedLocking) {
1110 revoke_biases_of_monitors(thread, fr, map);
1111 }
1112 deoptimize_single_frame(thread, fr);
1113
1114 }
1115
1116
1117 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1118 // Compute frame and register map based on thread and sp.
1119 RegisterMap reg_map(thread, UseBiasedLocking);
1120 frame fr = thread->last_frame();
1121 while (fr.id() != id) {
1122 fr = fr.sender(®_map);
1123 }
1124 deoptimize(thread, fr, ®_map);
1125 }
1126
1127
1128 // JVMTI PopFrame support
1129 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1130 {
1131 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1132 }
1133 JRT_END
1134
1135
1136 #if defined(COMPILER2) || defined(SHARK)
1137 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1138 // in case of an unresolved klass entry, load the class.
1139 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1140 klassOop tk = constant_pool->klass_at(index, CHECK);
1141 return;
1142 }
1143
1144 if (!constant_pool->tag_at(index).is_symbol()) return;
1145
1146 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1147 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1148
1149 // class name?
1150 if (symbol->byte_at(0) != '(') {
1151 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1152 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1153 return;
1154 }
1155
1156 // then it must be a signature!
1157 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1158 if (ss.is_object()) {
1159 symbolOop s = ss.as_symbol(CHECK);
1160 symbolHandle class_name (THREAD, s);
1161 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1162 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1163 }
1164 }
1165 }
1166
1167
1168 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1169 EXCEPTION_MARK;
1170 load_class_by_index(constant_pool, index, THREAD);
1171 if (HAS_PENDING_EXCEPTION) {
1172 // Exception happened during classloading. We ignore the exception here, since it
1173 // is going to be rethrown since the current activation is going to be deoptimzied and
1174 // the interpreter will re-execute the bytecode.
1175 CLEAR_PENDING_EXCEPTION;
1176 }
1177 }
1178
1179 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1180 HandleMark hm;
1181
1182 // uncommon_trap() is called at the beginning of the uncommon trap
1183 // handler. Note this fact before we start generating temporary frames
1184 // that can confuse an asynchronous stack walker. This counter is
1185 // decremented at the end of unpack_frames().
1186 thread->inc_in_deopt_handler();
1187
1188 // We need to update the map if we have biased locking.
1189 RegisterMap reg_map(thread, UseBiasedLocking);
1190 frame stub_frame = thread->last_frame();
1191 frame fr = stub_frame.sender(®_map);
1192 // Make sure the calling nmethod is not getting deoptimized and removed
1193 // before we are done with it.
1194 nmethodLocker nl(fr.pc());
1195
1196 {
1197 ResourceMark rm;
1198
1199 // Revoke biases of any monitors in the frame to ensure we can migrate them
1200 revoke_biases_of_monitors(thread, fr, ®_map);
1201
1202 DeoptReason reason = trap_request_reason(trap_request);
1203 DeoptAction action = trap_request_action(trap_request);
1204 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1205
1206 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1207 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1208 compiledVFrame* cvf = compiledVFrame::cast(vf);
1209
1210 nmethod* nm = cvf->code();
1211
1212 ScopeDesc* trap_scope = cvf->scope();
1213 methodHandle trap_method = trap_scope->method();
1214 int trap_bci = trap_scope->bci();
1215 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code();
1216
1217 // Record this event in the histogram.
1218 gather_statistics(reason, action, trap_bc);
1219
1220 // Ensure that we can record deopt. history:
1221 bool create_if_missing = ProfileTraps;
1222
1223 methodDataHandle trap_mdo
1224 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1225
1226 // Print a bunch of diagnostics, if requested.
1227 if (TraceDeoptimization || LogCompilation) {
1228 ResourceMark rm;
1229 ttyLocker ttyl;
1230 char buf[100];
1231 if (xtty != NULL) {
1232 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1233 os::current_thread_id(),
1234 format_trap_request(buf, sizeof(buf), trap_request));
1235 nm->log_identity(xtty);
1236 }
1237 symbolHandle class_name;
1238 bool unresolved = false;
1239 if (unloaded_class_index >= 0) {
1240 constantPoolHandle constants (THREAD, trap_method->constants());
1241 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1242 class_name = symbolHandle(THREAD,
1243 constants->klass_name_at(unloaded_class_index));
1244 unresolved = true;
1245 if (xtty != NULL)
1246 xtty->print(" unresolved='1'");
1247 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1248 class_name = symbolHandle(THREAD,
1249 constants->symbol_at(unloaded_class_index));
1250 }
1251 if (xtty != NULL)
1252 xtty->name(class_name);
1253 }
1254 if (xtty != NULL && trap_mdo.not_null()) {
1255 // Dump the relevant MDO state.
1256 // This is the deopt count for the current reason, any previous
1257 // reasons or recompiles seen at this point.
1258 int dcnt = trap_mdo->trap_count(reason);
1259 if (dcnt != 0)
1260 xtty->print(" count='%d'", dcnt);
1261 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1262 int dos = (pdata == NULL)? 0: pdata->trap_state();
1263 if (dos != 0) {
1264 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1265 if (trap_state_is_recompiled(dos)) {
1266 int recnt2 = trap_mdo->overflow_recompile_count();
1267 if (recnt2 != 0)
1268 xtty->print(" recompiles2='%d'", recnt2);
1269 }
1270 }
1271 }
1272 if (xtty != NULL) {
1273 xtty->stamp();
1274 xtty->end_head();
1275 }
1276 if (TraceDeoptimization) { // make noise on the tty
1277 tty->print("Uncommon trap occurred in");
1278 nm->method()->print_short_name(tty);
1279 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1280 fr.pc(),
1281 (int) os::current_thread_id(),
1282 trap_reason_name(reason),
1283 trap_action_name(action),
1284 unloaded_class_index);
1285 if (class_name.not_null()) {
1286 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1287 class_name->print_symbol_on(tty);
1288 }
1289 tty->cr();
1290 }
1291 if (xtty != NULL) {
1292 // Log the precise location of the trap.
1293 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1294 xtty->begin_elem("jvms bci='%d'", sd->bci());
1295 xtty->method(sd->method());
1296 xtty->end_elem();
1297 if (sd->is_top()) break;
1298 }
1299 xtty->tail("uncommon_trap");
1300 }
1301 }
1302 // (End diagnostic printout.)
1303
1304 // Load class if necessary
1305 if (unloaded_class_index >= 0) {
1306 constantPoolHandle constants(THREAD, trap_method->constants());
1307 load_class_by_index(constants, unloaded_class_index);
1308 }
1309
1310 // Flush the nmethod if necessary and desirable.
1311 //
1312 // We need to avoid situations where we are re-flushing the nmethod
1313 // because of a hot deoptimization site. Repeated flushes at the same
1314 // point need to be detected by the compiler and avoided. If the compiler
1315 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1316 // module must take measures to avoid an infinite cycle of recompilation
1317 // and deoptimization. There are several such measures:
1318 //
1319 // 1. If a recompilation is ordered a second time at some site X
1320 // and for the same reason R, the action is adjusted to 'reinterpret',
1321 // to give the interpreter time to exercise the method more thoroughly.
1322 // If this happens, the method's overflow_recompile_count is incremented.
1323 //
1324 // 2. If the compiler fails to reduce the deoptimization rate, then
1325 // the method's overflow_recompile_count will begin to exceed the set
1326 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1327 // is adjusted to 'make_not_compilable', and the method is abandoned
1328 // to the interpreter. This is a performance hit for hot methods,
1329 // but is better than a disastrous infinite cycle of recompilations.
1330 // (Actually, only the method containing the site X is abandoned.)
1331 //
1332 // 3. In parallel with the previous measures, if the total number of
1333 // recompilations of a method exceeds the much larger set limit
1334 // PerMethodRecompilationCutoff, the method is abandoned.
1335 // This should only happen if the method is very large and has
1336 // many "lukewarm" deoptimizations. The code which enforces this
1337 // limit is elsewhere (class nmethod, class methodOopDesc).
1338 //
1339 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1340 // to recompile at each bytecode independently of the per-BCI cutoff.
1341 //
1342 // The decision to update code is up to the compiler, and is encoded
1343 // in the Action_xxx code. If the compiler requests Action_none
1344 // no trap state is changed, no compiled code is changed, and the
1345 // computation suffers along in the interpreter.
1346 //
1347 // The other action codes specify various tactics for decompilation
1348 // and recompilation. Action_maybe_recompile is the loosest, and
1349 // allows the compiled code to stay around until enough traps are seen,
1350 // and until the compiler gets around to recompiling the trapping method.
1351 //
1352 // The other actions cause immediate removal of the present code.
1353
1354 bool update_trap_state = true;
1355 bool make_not_entrant = false;
1356 bool make_not_compilable = false;
1357 bool reprofile = false;
1358 switch (action) {
1359 case Action_none:
1360 // Keep the old code.
1361 update_trap_state = false;
1362 break;
1363 case Action_maybe_recompile:
1364 // Do not need to invalidate the present code, but we can
1365 // initiate another
1366 // Start compiler without (necessarily) invalidating the nmethod.
1367 // The system will tolerate the old code, but new code should be
1368 // generated when possible.
1369 break;
1370 case Action_reinterpret:
1371 // Go back into the interpreter for a while, and then consider
1372 // recompiling form scratch.
1373 make_not_entrant = true;
1374 // Reset invocation counter for outer most method.
1375 // This will allow the interpreter to exercise the bytecodes
1376 // for a while before recompiling.
1377 // By contrast, Action_make_not_entrant is immediate.
1378 //
1379 // Note that the compiler will track null_check, null_assert,
1380 // range_check, and class_check events and log them as if they
1381 // had been traps taken from compiled code. This will update
1382 // the MDO trap history so that the next compilation will
1383 // properly detect hot trap sites.
1384 reprofile = true;
1385 break;
1386 case Action_make_not_entrant:
1387 // Request immediate recompilation, and get rid of the old code.
1388 // Make them not entrant, so next time they are called they get
1389 // recompiled. Unloaded classes are loaded now so recompile before next
1390 // time they are called. Same for uninitialized. The interpreter will
1391 // link the missing class, if any.
1392 make_not_entrant = true;
1393 break;
1394 case Action_make_not_compilable:
1395 // Give up on compiling this method at all.
1396 make_not_entrant = true;
1397 make_not_compilable = true;
1398 break;
1399 default:
1400 ShouldNotReachHere();
1401 }
1402
1403 // Setting +ProfileTraps fixes the following, on all platforms:
1404 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1405 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1406 // recompile relies on a methodDataOop to record heroic opt failures.
1407
1408 // Whether the interpreter is producing MDO data or not, we also need
1409 // to use the MDO to detect hot deoptimization points and control
1410 // aggressive optimization.
1411 bool inc_recompile_count = false;
1412 ProfileData* pdata = NULL;
1413 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1414 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1415 uint this_trap_count = 0;
1416 bool maybe_prior_trap = false;
1417 bool maybe_prior_recompile = false;
1418 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1419 //outputs:
1420 this_trap_count,
1421 maybe_prior_trap,
1422 maybe_prior_recompile);
1423 // Because the interpreter also counts null, div0, range, and class
1424 // checks, these traps from compiled code are double-counted.
1425 // This is harmless; it just means that the PerXTrapLimit values
1426 // are in effect a little smaller than they look.
1427
1428 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1429 if (per_bc_reason != Reason_none) {
1430 // Now take action based on the partially known per-BCI history.
1431 if (maybe_prior_trap
1432 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1433 // If there are too many traps at this BCI, force a recompile.
1434 // This will allow the compiler to see the limit overflow, and
1435 // take corrective action, if possible. The compiler generally
1436 // does not use the exact PerBytecodeTrapLimit value, but instead
1437 // changes its tactics if it sees any traps at all. This provides
1438 // a little hysteresis, delaying a recompile until a trap happens
1439 // several times.
1440 //
1441 // Actually, since there is only one bit of counter per BCI,
1442 // the possible per-BCI counts are {0,1,(per-method count)}.
1443 // This produces accurate results if in fact there is only
1444 // one hot trap site, but begins to get fuzzy if there are
1445 // many sites. For example, if there are ten sites each
1446 // trapping two or more times, they each get the blame for
1447 // all of their traps.
1448 make_not_entrant = true;
1449 }
1450
1451 // Detect repeated recompilation at the same BCI, and enforce a limit.
1452 if (make_not_entrant && maybe_prior_recompile) {
1453 // More than one recompile at this point.
1454 inc_recompile_count = maybe_prior_trap;
1455 }
1456 } else {
1457 // For reasons which are not recorded per-bytecode, we simply
1458 // force recompiles unconditionally.
1459 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1460 make_not_entrant = true;
1461 }
1462
1463 // Go back to the compiler if there are too many traps in this method.
1464 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1465 // If there are too many traps in this method, force a recompile.
1466 // This will allow the compiler to see the limit overflow, and
1467 // take corrective action, if possible.
1468 // (This condition is an unlikely backstop only, because the
1469 // PerBytecodeTrapLimit is more likely to take effect first,
1470 // if it is applicable.)
1471 make_not_entrant = true;
1472 }
1473
1474 // Here's more hysteresis: If there has been a recompile at
1475 // this trap point already, run the method in the interpreter
1476 // for a while to exercise it more thoroughly.
1477 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1478 reprofile = true;
1479 }
1480
1481 }
1482
1483 // Take requested actions on the method:
1484
1485 // Recompile
1486 if (make_not_entrant) {
1487 if (!nm->make_not_entrant()) {
1488 return; // the call did not change nmethod's state
1489 }
1490
1491 if (pdata != NULL) {
1492 // Record the recompilation event, if any.
1493 int tstate0 = pdata->trap_state();
1494 int tstate1 = trap_state_set_recompiled(tstate0, true);
1495 if (tstate1 != tstate0)
1496 pdata->set_trap_state(tstate1);
1497 }
1498 }
1499
1500 if (inc_recompile_count) {
1501 trap_mdo->inc_overflow_recompile_count();
1502 if ((uint)trap_mdo->overflow_recompile_count() >
1503 (uint)PerBytecodeRecompilationCutoff) {
1504 // Give up on the method containing the bad BCI.
1505 if (trap_method() == nm->method()) {
1506 make_not_compilable = true;
1507 } else {
1508 trap_method->set_not_compilable(CompLevel_full_optimization);
1509 // But give grace to the enclosing nm->method().
1510 }
1511 }
1512 }
1513
1514 // Reprofile
1515 if (reprofile) {
1516 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1517 }
1518
1519 // Give up compiling
1520 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1521 assert(make_not_entrant, "consistent");
1522 nm->method()->set_not_compilable(CompLevel_full_optimization);
1523 }
1524
1525 } // Free marked resources
1526
1527 }
1528 JRT_END
1529
1530 methodDataOop
1531 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1532 bool create_if_missing) {
1533 Thread* THREAD = thread;
1534 methodDataOop mdo = m()->method_data();
1535 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1536 // Build an MDO. Ignore errors like OutOfMemory;
1537 // that simply means we won't have an MDO to update.
1538 methodOopDesc::build_interpreter_method_data(m, THREAD);
1539 if (HAS_PENDING_EXCEPTION) {
1540 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1541 CLEAR_PENDING_EXCEPTION;
1542 }
1543 mdo = m()->method_data();
1544 }
1545 return mdo;
1546 }
1547
1548 ProfileData*
1549 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1550 int trap_bci,
1551 Deoptimization::DeoptReason reason,
1552 //outputs:
1553 uint& ret_this_trap_count,
1554 bool& ret_maybe_prior_trap,
1555 bool& ret_maybe_prior_recompile) {
1556 uint prior_trap_count = trap_mdo->trap_count(reason);
1557 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1558
1559 // If the runtime cannot find a place to store trap history,
1560 // it is estimated based on the general condition of the method.
1561 // If the method has ever been recompiled, or has ever incurred
1562 // a trap with the present reason , then this BCI is assumed
1563 // (pessimistically) to be the culprit.
1564 bool maybe_prior_trap = (prior_trap_count != 0);
1565 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1566 ProfileData* pdata = NULL;
1567
1568
1569 // For reasons which are recorded per bytecode, we check per-BCI data.
1570 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1571 if (per_bc_reason != Reason_none) {
1572 // Find the profile data for this BCI. If there isn't one,
1573 // try to allocate one from the MDO's set of spares.
1574 // This will let us detect a repeated trap at this point.
1575 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1576
1577 if (pdata != NULL) {
1578 // Query the trap state of this profile datum.
1579 int tstate0 = pdata->trap_state();
1580 if (!trap_state_has_reason(tstate0, per_bc_reason))
1581 maybe_prior_trap = false;
1582 if (!trap_state_is_recompiled(tstate0))
1583 maybe_prior_recompile = false;
1584
1585 // Update the trap state of this profile datum.
1586 int tstate1 = tstate0;
1587 // Record the reason.
1588 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1589 // Store the updated state on the MDO, for next time.
1590 if (tstate1 != tstate0)
1591 pdata->set_trap_state(tstate1);
1592 } else {
1593 if (LogCompilation && xtty != NULL) {
1594 ttyLocker ttyl;
1595 // Missing MDP? Leave a small complaint in the log.
1596 xtty->elem("missing_mdp bci='%d'", trap_bci);
1597 }
1598 }
1599 }
1600
1601 // Return results:
1602 ret_this_trap_count = this_trap_count;
1603 ret_maybe_prior_trap = maybe_prior_trap;
1604 ret_maybe_prior_recompile = maybe_prior_recompile;
1605 return pdata;
1606 }
1607
1608 void
1609 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1610 ResourceMark rm;
1611 // Ignored outputs:
1612 uint ignore_this_trap_count;
1613 bool ignore_maybe_prior_trap;
1614 bool ignore_maybe_prior_recompile;
1615 query_update_method_data(trap_mdo, trap_bci,
1616 (DeoptReason)reason,
1617 ignore_this_trap_count,
1618 ignore_maybe_prior_trap,
1619 ignore_maybe_prior_recompile);
1620 }
1621
1622 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1623
1624 // Still in Java no safepoints
1625 {
1626 // This enters VM and may safepoint
1627 uncommon_trap_inner(thread, trap_request);
1628 }
1629 return fetch_unroll_info_helper(thread);
1630 }
1631
1632 // Local derived constants.
1633 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1634 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1635 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1636
1637 //---------------------------trap_state_reason---------------------------------
1638 Deoptimization::DeoptReason
1639 Deoptimization::trap_state_reason(int trap_state) {
1640 // This assert provides the link between the width of DataLayout::trap_bits
1641 // and the encoding of "recorded" reasons. It ensures there are enough
1642 // bits to store all needed reasons in the per-BCI MDO profile.
1643 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1644 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1645 trap_state -= recompile_bit;
1646 if (trap_state == DS_REASON_MASK) {
1647 return Reason_many;
1648 } else {
1649 assert((int)Reason_none == 0, "state=0 => Reason_none");
1650 return (DeoptReason)trap_state;
1651 }
1652 }
1653 //-------------------------trap_state_has_reason-------------------------------
1654 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1655 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1656 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1657 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1658 trap_state -= recompile_bit;
1659 if (trap_state == DS_REASON_MASK) {
1660 return -1; // true, unspecifically (bottom of state lattice)
1661 } else if (trap_state == reason) {
1662 return 1; // true, definitely
1663 } else if (trap_state == 0) {
1664 return 0; // false, definitely (top of state lattice)
1665 } else {
1666 return 0; // false, definitely
1667 }
1668 }
1669 //-------------------------trap_state_add_reason-------------------------------
1670 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1671 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1672 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1673 trap_state -= recompile_bit;
1674 if (trap_state == DS_REASON_MASK) {
1675 return trap_state + recompile_bit; // already at state lattice bottom
1676 } else if (trap_state == reason) {
1677 return trap_state + recompile_bit; // the condition is already true
1678 } else if (trap_state == 0) {
1679 return reason + recompile_bit; // no condition has yet been true
1680 } else {
1681 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1682 }
1683 }
1684 //-----------------------trap_state_is_recompiled------------------------------
1685 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1686 return (trap_state & DS_RECOMPILE_BIT) != 0;
1687 }
1688 //-----------------------trap_state_set_recompiled-----------------------------
1689 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1690 if (z) return trap_state | DS_RECOMPILE_BIT;
1691 else return trap_state & ~DS_RECOMPILE_BIT;
1692 }
1693 //---------------------------format_trap_state---------------------------------
1694 // This is used for debugging and diagnostics, including hotspot.log output.
1695 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1696 int trap_state) {
1697 DeoptReason reason = trap_state_reason(trap_state);
1698 bool recomp_flag = trap_state_is_recompiled(trap_state);
1699 // Re-encode the state from its decoded components.
1700 int decoded_state = 0;
1701 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1702 decoded_state = trap_state_add_reason(decoded_state, reason);
1703 if (recomp_flag)
1704 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1705 // If the state re-encodes properly, format it symbolically.
1706 // Because this routine is used for debugging and diagnostics,
1707 // be robust even if the state is a strange value.
1708 size_t len;
1709 if (decoded_state != trap_state) {
1710 // Random buggy state that doesn't decode??
1711 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1712 } else {
1713 len = jio_snprintf(buf, buflen, "%s%s",
1714 trap_reason_name(reason),
1715 recomp_flag ? " recompiled" : "");
1716 }
1717 if (len >= buflen)
1718 buf[buflen-1] = '\0';
1719 return buf;
1720 }
1721
1722
1723 //--------------------------------statics--------------------------------------
1724 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1725 = Deoptimization::Action_reinterpret;
1726 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1727 // Note: Keep this in sync. with enum DeoptReason.
1728 "none",
1729 "null_check",
1730 "null_assert",
1731 "range_check",
1732 "class_check",
1733 "array_check",
1734 "intrinsic",
1735 "bimorphic",
1736 "unloaded",
1737 "uninitialized",
1738 "unreached",
1739 "unhandled",
1740 "constraint",
1741 "div0_check",
1742 "age",
1743 "predicate"
1744 };
1745 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1746 // Note: Keep this in sync. with enum DeoptAction.
1747 "none",
1748 "maybe_recompile",
1749 "reinterpret",
1750 "make_not_entrant",
1751 "make_not_compilable"
1752 };
1753
1754 const char* Deoptimization::trap_reason_name(int reason) {
1755 if (reason == Reason_many) return "many";
1756 if ((uint)reason < Reason_LIMIT)
1757 return _trap_reason_name[reason];
1758 static char buf[20];
1759 sprintf(buf, "reason%d", reason);
1760 return buf;
1761 }
1762 const char* Deoptimization::trap_action_name(int action) {
1763 if ((uint)action < Action_LIMIT)
1764 return _trap_action_name[action];
1765 static char buf[20];
1766 sprintf(buf, "action%d", action);
1767 return buf;
1768 }
1769
1770 // This is used for debugging and diagnostics, including hotspot.log output.
1771 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1772 int trap_request) {
1773 jint unloaded_class_index = trap_request_index(trap_request);
1774 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1775 const char* action = trap_action_name(trap_request_action(trap_request));
1776 size_t len;
1777 if (unloaded_class_index < 0) {
1778 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1779 reason, action);
1780 } else {
1781 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1782 reason, action, unloaded_class_index);
1783 }
1784 if (len >= buflen)
1785 buf[buflen-1] = '\0';
1786 return buf;
1787 }
1788
1789 juint Deoptimization::_deoptimization_hist
1790 [Deoptimization::Reason_LIMIT]
1791 [1 + Deoptimization::Action_LIMIT]
1792 [Deoptimization::BC_CASE_LIMIT]
1793 = {0};
1794
1795 enum {
1796 LSB_BITS = 8,
1797 LSB_MASK = right_n_bits(LSB_BITS)
1798 };
1799
1800 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1801 Bytecodes::Code bc) {
1802 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1803 assert(action >= 0 && action < Action_LIMIT, "oob");
1804 _deoptimization_hist[Reason_none][0][0] += 1; // total
1805 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1806 juint* cases = _deoptimization_hist[reason][1+action];
1807 juint* bc_counter_addr = NULL;
1808 juint bc_counter = 0;
1809 // Look for an unused counter, or an exact match to this BC.
1810 if (bc != Bytecodes::_illegal) {
1811 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1812 juint* counter_addr = &cases[bc_case];
1813 juint counter = *counter_addr;
1814 if ((counter == 0 && bc_counter_addr == NULL)
1815 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1816 // this counter is either free or is already devoted to this BC
1817 bc_counter_addr = counter_addr;
1818 bc_counter = counter | bc;
1819 }
1820 }
1821 }
1822 if (bc_counter_addr == NULL) {
1823 // Overflow, or no given bytecode.
1824 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1825 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1826 }
1827 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1828 }
1829
1830 jint Deoptimization::total_deoptimization_count() {
1831 return _deoptimization_hist[Reason_none][0][0];
1832 }
1833
1834 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1835 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1836 return _deoptimization_hist[reason][0][0];
1837 }
1838
1839 void Deoptimization::print_statistics() {
1840 juint total = total_deoptimization_count();
1841 juint account = total;
1842 if (total != 0) {
1843 ttyLocker ttyl;
1844 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1845 tty->print_cr("Deoptimization traps recorded:");
1846 #define PRINT_STAT_LINE(name, r) \
1847 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1848 PRINT_STAT_LINE("total", total);
1849 // For each non-zero entry in the histogram, print the reason,
1850 // the action, and (if specifically known) the type of bytecode.
1851 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1852 for (int action = 0; action < Action_LIMIT; action++) {
1853 juint* cases = _deoptimization_hist[reason][1+action];
1854 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1855 juint counter = cases[bc_case];
1856 if (counter != 0) {
1857 char name[1*K];
1858 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1859 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1860 bc = Bytecodes::_illegal;
1861 sprintf(name, "%s/%s/%s",
1862 trap_reason_name(reason),
1863 trap_action_name(action),
1864 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1865 juint r = counter >> LSB_BITS;
1866 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1867 account -= r;
1868 }
1869 }
1870 }
1871 }
1872 if (account != 0) {
1873 PRINT_STAT_LINE("unaccounted", account);
1874 }
1875 #undef PRINT_STAT_LINE
1876 if (xtty != NULL) xtty->tail("statistics");
1877 }
1878 }
1879 #else // COMPILER2 || SHARK
1880
1881
1882 // Stubs for C1 only system.
1883 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1884 return false;
1885 }
1886
1887 const char* Deoptimization::trap_reason_name(int reason) {
1888 return "unknown";
1889 }
1890
1891 void Deoptimization::print_statistics() {
1892 // no output
1893 }
1894
1895 void
1896 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1897 // no udpate
1898 }
1899
1900 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1901 return 0;
1902 }
1903
1904 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1905 Bytecodes::Code bc) {
1906 // no update
1907 }
1908
1909 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1910 int trap_state) {
1911 jio_snprintf(buf, buflen, "#%d", trap_state);
1912 return buf;
1913 }
1914
1915 #endif // COMPILER2 || SHARK