1 /*
2 * Copyright 1997-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
20 * CA 95054 USA or visit www.sun.com if you need additional information or
21 * have any questions.
22 *
23 */
24
25 #include "incls/_precompiled.incl"
26 #include "incls/_deoptimization.cpp.incl"
27
28 bool DeoptimizationMarker::_is_active = false;
29
30 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
31 int caller_adjustment,
32 int number_of_frames,
33 intptr_t* frame_sizes,
34 address* frame_pcs,
35 BasicType return_type) {
36 _size_of_deoptimized_frame = size_of_deoptimized_frame;
37 _caller_adjustment = caller_adjustment;
38 _number_of_frames = number_of_frames;
39 _frame_sizes = frame_sizes;
40 _frame_pcs = frame_pcs;
41 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
42 _return_type = return_type;
43 // PD (x86 only)
44 _counter_temp = 0;
45 _initial_fp = 0;
46 _unpack_kind = 0;
47 _sender_sp_temp = 0;
48
49 _total_frame_sizes = size_of_frames();
50 }
51
52
53 Deoptimization::UnrollBlock::~UnrollBlock() {
54 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
55 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
56 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
57 }
58
59
60 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
61 assert(register_number < RegisterMap::reg_count, "checking register number");
62 return &_register_block[register_number * 2];
63 }
64
65
66
67 int Deoptimization::UnrollBlock::size_of_frames() const {
68 // Acount first for the adjustment of the initial frame
69 int result = _caller_adjustment;
70 for (int index = 0; index < number_of_frames(); index++) {
71 result += frame_sizes()[index];
72 }
73 return result;
74 }
75
76
77 void Deoptimization::UnrollBlock::print() {
78 ttyLocker ttyl;
79 tty->print_cr("UnrollBlock");
80 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
81 tty->print( " frame_sizes: ");
82 for (int index = 0; index < number_of_frames(); index++) {
83 tty->print("%d ", frame_sizes()[index]);
84 }
85 tty->cr();
86 }
87
88
89 // In order to make fetch_unroll_info work properly with escape
90 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
91 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
92 // of previously eliminated objects occurs in realloc_objects, which is
93 // called from the method fetch_unroll_info_helper below.
94 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
95 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
96 // but makes the entry a little slower. There is however a little dance we have to
97 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
98
99 // fetch_unroll_info() is called at the beginning of the deoptimization
100 // handler. Note this fact before we start generating temporary frames
101 // that can confuse an asynchronous stack walker. This counter is
102 // decremented at the end of unpack_frames().
103 thread->inc_in_deopt_handler();
104
105 return fetch_unroll_info_helper(thread);
106 JRT_END
107
108
109 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
110 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
111
112 // Note: there is a safepoint safety issue here. No matter whether we enter
113 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
114 // the vframeArray is created.
115 //
116
117 // Allocate our special deoptimization ResourceMark
118 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
119 assert(thread->deopt_mark() == NULL, "Pending deopt!");
120 thread->set_deopt_mark(dmark);
121
122 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
123 RegisterMap map(thread, true);
124 RegisterMap dummy_map(thread, false);
125 // Now get the deoptee with a valid map
126 frame deoptee = stub_frame.sender(&map);
127
128 // Create a growable array of VFrames where each VFrame represents an inlined
129 // Java frame. This storage is allocated with the usual system arena.
130 assert(deoptee.is_compiled_frame(), "Wrong frame type");
131 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
132 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
133 while (!vf->is_top()) {
134 assert(vf->is_compiled_frame(), "Wrong frame type");
135 chunk->push(compiledVFrame::cast(vf));
136 vf = vf->sender();
137 }
138 assert(vf->is_compiled_frame(), "Wrong frame type");
139 chunk->push(compiledVFrame::cast(vf));
140
141 #ifdef COMPILER2
142 // Reallocate the non-escaping objects and restore their fields. Then
143 // relock objects if synchronization on them was eliminated.
144 if (DoEscapeAnalysis) {
145 if (EliminateAllocations) {
146 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
147 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
148 bool reallocated = false;
149 if (objects != NULL) {
150 JRT_BLOCK
151 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
152 JRT_END
153 }
154 if (reallocated) {
155 reassign_fields(&deoptee, &map, objects);
156 #ifndef PRODUCT
157 if (TraceDeoptimization) {
158 ttyLocker ttyl;
159 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
160 print_objects(objects);
161 }
162 #endif
163 }
164 }
165 if (EliminateLocks) {
166 #ifndef PRODUCT
167 bool first = true;
168 #endif
169 for (int i = 0; i < chunk->length(); i++) {
170 compiledVFrame* cvf = chunk->at(i);
171 assert (cvf->scope() != NULL,"expect only compiled java frames");
172 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
173 if (monitors->is_nonempty()) {
174 relock_objects(monitors, thread);
175 #ifndef PRODUCT
176 if (TraceDeoptimization) {
177 ttyLocker ttyl;
178 for (int j = 0; j < monitors->length(); j++) {
179 MonitorInfo* mi = monitors->at(j);
180 if (mi->eliminated()) {
181 if (first) {
182 first = false;
183 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
184 }
185 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
186 }
187 }
188 }
189 #endif
190 }
191 }
192 }
193 }
194 #endif // COMPILER2
195 // Ensure that no safepoint is taken after pointers have been stored
196 // in fields of rematerialized objects. If a safepoint occurs from here on
197 // out the java state residing in the vframeArray will be missed.
198 No_Safepoint_Verifier no_safepoint;
199
200 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
201
202 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
203 thread->set_vframe_array_head(array);
204
205 // Now that the vframeArray has been created if we have any deferred local writes
206 // added by jvmti then we can free up that structure as the data is now in the
207 // vframeArray
208
209 if (thread->deferred_locals() != NULL) {
210 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
211 int i = 0;
212 do {
213 // Because of inlining we could have multiple vframes for a single frame
214 // and several of the vframes could have deferred writes. Find them all.
215 if (list->at(i)->id() == array->original().id()) {
216 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
217 list->remove_at(i);
218 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
219 delete dlv;
220 } else {
221 i++;
222 }
223 } while ( i < list->length() );
224 if (list->length() == 0) {
225 thread->set_deferred_locals(NULL);
226 // free the list and elements back to C heap.
227 delete list;
228 }
229
230 }
231
232 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
233 CodeBlob* cb = stub_frame.cb();
234 // Verify we have the right vframeArray
235 assert(cb->frame_size() >= 0, "Unexpected frame size");
236 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
237
238 #ifdef ASSERT
239 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
240 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
241 #endif
242 // This is a guarantee instead of an assert because if vframe doesn't match
243 // we will unpack the wrong deoptimized frame and wind up in strange places
244 // where it will be very difficult to figure out what went wrong. Better
245 // to die an early death here than some very obscure death later when the
246 // trail is cold.
247 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
248 // in that it will fail to detect a problem when there is one. This needs
249 // more work in tiger timeframe.
250 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
251
252 int number_of_frames = array->frames();
253
254 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
255 // virtual activation, which is the reverse of the elements in the vframes array.
256 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
257 // +1 because we always have an interpreter return address for the final slot.
258 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
259 int callee_parameters = 0;
260 int callee_locals = 0;
261 int popframe_extra_args = 0;
262 // Create an interpreter return address for the stub to use as its return
263 // address so the skeletal frames are perfectly walkable
264 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
265
266 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
267 // activation be put back on the expression stack of the caller for reexecution
268 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
269 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
270 }
271
272 //
273 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
274 // frame_sizes/frame_pcs[1] next oldest frame (int)
275 // frame_sizes/frame_pcs[n] youngest frame (int)
276 //
277 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
278 // owns the space for the return address to it's caller). Confusing ain't it.
279 //
280 // The vframe array can address vframes with indices running from
281 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
282 // When we create the skeletal frames we need the oldest frame to be in the zero slot
283 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
284 // so things look a little strange in this loop.
285 //
286 for (int index = 0; index < array->frames(); index++ ) {
287 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
288 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
289 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
290 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
291 callee_locals,
292 index == 0,
293 popframe_extra_args);
294 // This pc doesn't have to be perfect just good enough to identify the frame
295 // as interpreted so the skeleton frame will be walkable
296 // The correct pc will be set when the skeleton frame is completely filled out
297 // The final pc we store in the loop is wrong and will be overwritten below
298 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
299
300 callee_parameters = array->element(index)->method()->size_of_parameters();
301 callee_locals = array->element(index)->method()->max_locals();
302 popframe_extra_args = 0;
303 }
304
305 // Compute whether the root vframe returns a float or double value.
306 BasicType return_type;
307 {
308 HandleMark hm;
309 methodHandle method(thread, array->element(0)->method());
310 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci());
311 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL;
312 }
313
314 // Compute information for handling adapters and adjusting the frame size of the caller.
315 int caller_adjustment = 0;
316
317 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
318 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
319 // than simply use array->sender.pc(). This requires us to walk the current set of frames
320 //
321 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
322 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
323
324 // Compute the amount the oldest interpreter frame will have to adjust
325 // its caller's stack by. If the caller is a compiled frame then
326 // we pretend that the callee has no parameters so that the
327 // extension counts for the full amount of locals and not just
328 // locals-parms. This is because without a c2i adapter the parm
329 // area as created by the compiled frame will not be usable by
330 // the interpreter. (Depending on the calling convention there
331 // may not even be enough space).
332
333 // QQQ I'd rather see this pushed down into last_frame_adjust
334 // and have it take the sender (aka caller).
335
336 if (deopt_sender.is_compiled_frame()) {
337 caller_adjustment = last_frame_adjust(0, callee_locals);
338 } else if (callee_locals > callee_parameters) {
339 // The caller frame may need extending to accommodate
340 // non-parameter locals of the first unpacked interpreted frame.
341 // Compute that adjustment.
342 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
343 }
344
345
346 // If the sender is deoptimized the we must retrieve the address of the handler
347 // since the frame will "magically" show the original pc before the deopt
348 // and we'd undo the deopt.
349
350 frame_pcs[0] = deopt_sender.raw_pc();
351
352 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
353
354 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
355 caller_adjustment * BytesPerWord,
356 number_of_frames,
357 frame_sizes,
358 frame_pcs,
359 return_type);
360 #if defined(IA32) || defined(AMD64)
361 // We need a way to pass fp to the unpacking code so the skeletal frames
362 // come out correct. This is only needed for x86 because of c2 using ebp
363 // as an allocatable register. So this update is useless (and harmless)
364 // on the other platforms. It would be nice to do this in a different
365 // way but even the old style deoptimization had a problem with deriving
366 // this value. NEEDS_CLEANUP
367 // Note: now that c1 is using c2's deopt blob we must do this on all
368 // x86 based platforms
369 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
370 *fp_addr = array->sender().fp(); // was adapter_caller
371 #endif /* IA32 || AMD64 */
372
373 if (array->frames() > 1) {
374 if (VerifyStack && TraceDeoptimization) {
375 tty->print_cr("Deoptimizing method containing inlining");
376 }
377 }
378
379 array->set_unroll_block(info);
380 return info;
381 }
382
383 // Called to cleanup deoptimization data structures in normal case
384 // after unpacking to stack and when stack overflow error occurs
385 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
386 vframeArray *array) {
387
388 // Get array if coming from exception
389 if (array == NULL) {
390 array = thread->vframe_array_head();
391 }
392 thread->set_vframe_array_head(NULL);
393
394 // Free the previous UnrollBlock
395 vframeArray* old_array = thread->vframe_array_last();
396 thread->set_vframe_array_last(array);
397
398 if (old_array != NULL) {
399 UnrollBlock* old_info = old_array->unroll_block();
400 old_array->set_unroll_block(NULL);
401 delete old_info;
402 delete old_array;
403 }
404
405 // Deallocate any resource creating in this routine and any ResourceObjs allocated
406 // inside the vframeArray (StackValueCollections)
407
408 delete thread->deopt_mark();
409 thread->set_deopt_mark(NULL);
410
411
412 if (JvmtiExport::can_pop_frame()) {
413 #ifndef CC_INTERP
414 // Regardless of whether we entered this routine with the pending
415 // popframe condition bit set, we should always clear it now
416 thread->clear_popframe_condition();
417 #else
418 // C++ interpeter will clear has_pending_popframe when it enters
419 // with method_resume. For deopt_resume2 we clear it now.
420 if (thread->popframe_forcing_deopt_reexecution())
421 thread->clear_popframe_condition();
422 #endif /* CC_INTERP */
423 }
424
425 // unpack_frames() is called at the end of the deoptimization handler
426 // and (in C2) at the end of the uncommon trap handler. Note this fact
427 // so that an asynchronous stack walker can work again. This counter is
428 // incremented at the beginning of fetch_unroll_info() and (in C2) at
429 // the beginning of uncommon_trap().
430 thread->dec_in_deopt_handler();
431 }
432
433
434 // Return BasicType of value being returned
435 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
436
437 // We are already active int he special DeoptResourceMark any ResourceObj's we
438 // allocate will be freed at the end of the routine.
439
440 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
441 // but makes the entry a little slower. There is however a little dance we have to
442 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
443 ResetNoHandleMark rnhm; // No-op in release/product versions
444 HandleMark hm;
445
446 frame stub_frame = thread->last_frame();
447
448 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
449 // must point to the vframeArray for the unpack frame.
450 vframeArray* array = thread->vframe_array_head();
451
452 #ifndef PRODUCT
453 if (TraceDeoptimization) {
454 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
455 }
456 #endif
457
458 UnrollBlock* info = array->unroll_block();
459
460 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
461 array->unpack_to_stack(stub_frame, exec_mode);
462
463 BasicType bt = info->return_type();
464
465 // If we have an exception pending, claim that the return type is an oop
466 // so the deopt_blob does not overwrite the exception_oop.
467
468 if (exec_mode == Unpack_exception)
469 bt = T_OBJECT;
470
471 // Cleanup thread deopt data
472 cleanup_deopt_info(thread, array);
473
474 #ifndef PRODUCT
475 if (VerifyStack) {
476 ResourceMark res_mark;
477
478 // Verify that the just-unpacked frames match the interpreter's
479 // notions of expression stack and locals
480 vframeArray* cur_array = thread->vframe_array_last();
481 RegisterMap rm(thread, false);
482 rm.set_include_argument_oops(false);
483 bool is_top_frame = true;
484 int callee_size_of_parameters = 0;
485 int callee_max_locals = 0;
486 for (int i = 0; i < cur_array->frames(); i++) {
487 vframeArrayElement* el = cur_array->element(i);
488 frame* iframe = el->iframe();
489 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
490
491 // Get the oop map for this bci
492 InterpreterOopMap mask;
493 int cur_invoke_parameter_size = 0;
494 bool try_next_mask = false;
495 int next_mask_expression_stack_size = -1;
496 int top_frame_expression_stack_adjustment = 0;
497 methodHandle mh(thread, iframe->interpreter_frame_method());
498 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
499 BytecodeStream str(mh);
500 str.set_start(iframe->interpreter_frame_bci());
501 int max_bci = mh->code_size();
502 // Get to the next bytecode if possible
503 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
504 // Check to see if we can grab the number of outgoing arguments
505 // at an uncommon trap for an invoke (where the compiler
506 // generates debug info before the invoke has executed)
507 Bytecodes::Code cur_code = str.next();
508 if (cur_code == Bytecodes::_invokevirtual ||
509 cur_code == Bytecodes::_invokespecial ||
510 cur_code == Bytecodes::_invokestatic ||
511 cur_code == Bytecodes::_invokeinterface) {
512 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci());
513 symbolHandle signature(thread, invoke->signature());
514 ArgumentSizeComputer asc(signature);
515 cur_invoke_parameter_size = asc.size();
516 if (cur_code != Bytecodes::_invokestatic) {
517 // Add in receiver
518 ++cur_invoke_parameter_size;
519 }
520 }
521 if (str.bci() < max_bci) {
522 Bytecodes::Code bc = str.next();
523 if (bc >= 0) {
524 // The interpreter oop map generator reports results before
525 // the current bytecode has executed except in the case of
526 // calls. It seems to be hard to tell whether the compiler
527 // has emitted debug information matching the "state before"
528 // a given bytecode or the state after, so we try both
529 switch (cur_code) {
530 case Bytecodes::_invokevirtual:
531 case Bytecodes::_invokespecial:
532 case Bytecodes::_invokestatic:
533 case Bytecodes::_invokeinterface:
534 case Bytecodes::_athrow:
535 break;
536 default: {
537 InterpreterOopMap next_mask;
538 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
539 next_mask_expression_stack_size = next_mask.expression_stack_size();
540 // Need to subtract off the size of the result type of
541 // the bytecode because this is not described in the
542 // debug info but returned to the interpreter in the TOS
543 // caching register
544 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
545 if (bytecode_result_type != T_ILLEGAL) {
546 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
547 }
548 assert(top_frame_expression_stack_adjustment >= 0, "");
549 try_next_mask = true;
550 break;
551 }
552 }
553 }
554 }
555
556 // Verify stack depth and oops in frame
557 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
558 if (!(
559 /* SPARC */
560 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
561 /* x86 */
562 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
563 (try_next_mask &&
564 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
565 top_frame_expression_stack_adjustment))) ||
566 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
567 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
568 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
569 )) {
570 ttyLocker ttyl;
571
572 // Print out some information that will help us debug the problem
573 tty->print_cr("Wrong number of expression stack elements during deoptimization");
574 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
575 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
576 iframe->interpreter_frame_expression_stack_size());
577 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
578 tty->print_cr(" try_next_mask = %d", try_next_mask);
579 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
580 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
581 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
582 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
583 tty->print_cr(" exec_mode = %d", exec_mode);
584 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
585 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
586 tty->print_cr(" Interpreted frames:");
587 for (int k = 0; k < cur_array->frames(); k++) {
588 vframeArrayElement* el = cur_array->element(k);
589 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
590 }
591 cur_array->print_on_2(tty);
592 guarantee(false, "wrong number of expression stack elements during deopt");
593 }
594 VerifyOopClosure verify;
595 iframe->oops_interpreted_do(&verify, &rm, false);
596 callee_size_of_parameters = mh->size_of_parameters();
597 callee_max_locals = mh->max_locals();
598 is_top_frame = false;
599 }
600 }
601 #endif /* !PRODUCT */
602
603
604 return bt;
605 JRT_END
606
607
608 int Deoptimization::deoptimize_dependents() {
609 Threads::deoptimized_wrt_marked_nmethods();
610 return 0;
611 }
612
613
614 #ifdef COMPILER2
615 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
616 Handle pending_exception(thread->pending_exception());
617 const char* exception_file = thread->exception_file();
618 int exception_line = thread->exception_line();
619 thread->clear_pending_exception();
620
621 for (int i = 0; i < objects->length(); i++) {
622 assert(objects->at(i)->is_object(), "invalid debug information");
623 ObjectValue* sv = (ObjectValue*) objects->at(i);
624
625 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
626 oop obj = NULL;
627
628 if (k->oop_is_instance()) {
629 instanceKlass* ik = instanceKlass::cast(k());
630 obj = ik->allocate_instance(CHECK_(false));
631 } else if (k->oop_is_typeArray()) {
632 typeArrayKlass* ak = typeArrayKlass::cast(k());
633 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
634 int len = sv->field_size() / type2size[ak->element_type()];
635 obj = ak->allocate(len, CHECK_(false));
636 } else if (k->oop_is_objArray()) {
637 objArrayKlass* ak = objArrayKlass::cast(k());
638 obj = ak->allocate(sv->field_size(), CHECK_(false));
639 }
640
641 assert(obj != NULL, "allocation failed");
642 assert(sv->value().is_null(), "redundant reallocation");
643 sv->set_value(obj);
644 }
645
646 if (pending_exception.not_null()) {
647 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
648 }
649
650 return true;
651 }
652
653 // This assumes that the fields are stored in ObjectValue in the same order
654 // they are yielded by do_nonstatic_fields.
655 class FieldReassigner: public FieldClosure {
656 frame* _fr;
657 RegisterMap* _reg_map;
658 ObjectValue* _sv;
659 instanceKlass* _ik;
660 oop _obj;
661
662 int _i;
663 public:
664 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
665 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
666
667 int i() const { return _i; }
668
669
670 void do_field(fieldDescriptor* fd) {
671 intptr_t val;
672 StackValue* value =
673 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
674 int offset = fd->offset();
675 switch (fd->field_type()) {
676 case T_OBJECT: case T_ARRAY:
677 assert(value->type() == T_OBJECT, "Agreement.");
678 _obj->obj_field_put(offset, value->get_obj()());
679 break;
680
681 case T_LONG: case T_DOUBLE: {
682 assert(value->type() == T_INT, "Agreement.");
683 StackValue* low =
684 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
685 #ifdef _LP64
686 jlong res = (jlong)low->get_int();
687 #else
688 #ifdef SPARC
689 // For SPARC we have to swap high and low words.
690 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
691 #else
692 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
693 #endif //SPARC
694 #endif
695 _obj->long_field_put(offset, res);
696 break;
697 }
698 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
699 case T_INT: case T_FLOAT: // 4 bytes.
700 assert(value->type() == T_INT, "Agreement.");
701 val = value->get_int();
702 _obj->int_field_put(offset, (jint)*((jint*)&val));
703 break;
704
705 case T_SHORT: case T_CHAR: // 2 bytes
706 assert(value->type() == T_INT, "Agreement.");
707 val = value->get_int();
708 _obj->short_field_put(offset, (jshort)*((jint*)&val));
709 break;
710
711 case T_BOOLEAN: case T_BYTE: // 1 byte
712 assert(value->type() == T_INT, "Agreement.");
713 val = value->get_int();
714 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
715 break;
716
717 default:
718 ShouldNotReachHere();
719 }
720 _i++;
721 }
722 };
723
724 // restore elements of an eliminated type array
725 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
726 int index = 0;
727 intptr_t val;
728
729 for (int i = 0; i < sv->field_size(); i++) {
730 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
731 switch(type) {
732 case T_LONG: case T_DOUBLE: {
733 assert(value->type() == T_INT, "Agreement.");
734 StackValue* low =
735 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
736 #ifdef _LP64
737 jlong res = (jlong)low->get_int();
738 #else
739 #ifdef SPARC
740 // For SPARC we have to swap high and low words.
741 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
742 #else
743 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
744 #endif //SPARC
745 #endif
746 obj->long_at_put(index, res);
747 break;
748 }
749
750 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
751 case T_INT: case T_FLOAT: // 4 bytes.
752 assert(value->type() == T_INT, "Agreement.");
753 val = value->get_int();
754 obj->int_at_put(index, (jint)*((jint*)&val));
755 break;
756
757 case T_SHORT: case T_CHAR: // 2 bytes
758 assert(value->type() == T_INT, "Agreement.");
759 val = value->get_int();
760 obj->short_at_put(index, (jshort)*((jint*)&val));
761 break;
762
763 case T_BOOLEAN: case T_BYTE: // 1 byte
764 assert(value->type() == T_INT, "Agreement.");
765 val = value->get_int();
766 obj->bool_at_put(index, (jboolean)*((jint*)&val));
767 break;
768
769 default:
770 ShouldNotReachHere();
771 }
772 index++;
773 }
774 }
775
776
777 // restore fields of an eliminated object array
778 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
779 for (int i = 0; i < sv->field_size(); i++) {
780 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
781 assert(value->type() == T_OBJECT, "object element expected");
782 obj->obj_at_put(i, value->get_obj()());
783 }
784 }
785
786
787 // restore fields of all eliminated objects and arrays
788 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
789 for (int i = 0; i < objects->length(); i++) {
790 ObjectValue* sv = (ObjectValue*) objects->at(i);
791 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
792 Handle obj = sv->value();
793 assert(obj.not_null(), "reallocation was missed");
794
795 if (k->oop_is_instance()) {
796 instanceKlass* ik = instanceKlass::cast(k());
797 FieldReassigner reassign(fr, reg_map, sv, obj());
798 ik->do_nonstatic_fields(&reassign);
799 } else if (k->oop_is_typeArray()) {
800 typeArrayKlass* ak = typeArrayKlass::cast(k());
801 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
802 } else if (k->oop_is_objArray()) {
803 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
804 }
805 }
806 }
807
808
809 // relock objects for which synchronization was eliminated
810 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
811 for (int i = 0; i < monitors->length(); i++) {
812 MonitorInfo* mon_info = monitors->at(i);
813 if (mon_info->eliminated()) {
814 assert(mon_info->owner() != NULL, "reallocation was missed");
815 Handle obj = Handle(mon_info->owner());
816 markOop mark = obj->mark();
817 if (UseBiasedLocking && mark->has_bias_pattern()) {
818 // New allocated objects may have the mark set to anonymously biased.
819 // Also the deoptimized method may called methods with synchronization
820 // where the thread-local object is bias locked to the current thread.
821 assert(mark->is_biased_anonymously() ||
822 mark->biased_locker() == thread, "should be locked to current thread");
823 // Reset mark word to unbiased prototype.
824 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
825 obj->set_mark(unbiased_prototype);
826 }
827 BasicLock* lock = mon_info->lock();
828 ObjectSynchronizer::slow_enter(obj, lock, thread);
829 }
830 assert(mon_info->owner()->is_locked(), "object must be locked now");
831 }
832 }
833
834
835 #ifndef PRODUCT
836 // print information about reallocated objects
837 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
838 fieldDescriptor fd;
839
840 for (int i = 0; i < objects->length(); i++) {
841 ObjectValue* sv = (ObjectValue*) objects->at(i);
842 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
843 Handle obj = sv->value();
844
845 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
846 k->as_klassOop()->print_value();
847 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
848 tty->cr();
849
850 if (Verbose) {
851 k->oop_print_on(obj(), tty);
852 }
853 }
854 }
855 #endif
856 #endif // COMPILER2
857
858 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
859
860 #ifndef PRODUCT
861 if (TraceDeoptimization) {
862 ttyLocker ttyl;
863 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
864 fr.print_on(tty);
865 tty->print_cr(" Virtual frames (innermost first):");
866 for (int index = 0; index < chunk->length(); index++) {
867 compiledVFrame* vf = chunk->at(index);
868 tty->print(" %2d - ", index);
869 vf->print_value();
870 int bci = chunk->at(index)->raw_bci();
871 const char* code_name;
872 if (bci == SynchronizationEntryBCI) {
873 code_name = "sync entry";
874 } else {
875 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci);
876 code_name = Bytecodes::name(code);
877 }
878 tty->print(" - %s", code_name);
879 tty->print_cr(" @ bci %d ", bci);
880 if (Verbose) {
881 vf->print();
882 tty->cr();
883 }
884 }
885 }
886 #endif
887
888 // Register map for next frame (used for stack crawl). We capture
889 // the state of the deopt'ing frame's caller. Thus if we need to
890 // stuff a C2I adapter we can properly fill in the callee-save
891 // register locations.
892 frame caller = fr.sender(reg_map);
893 int frame_size = caller.sp() - fr.sp();
894
895 frame sender = caller;
896
897 // Since the Java thread being deoptimized will eventually adjust it's own stack,
898 // the vframeArray containing the unpacking information is allocated in the C heap.
899 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
900 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
901
902 // Compare the vframeArray to the collected vframes
903 assert(array->structural_compare(thread, chunk), "just checking");
904 Events::log("# vframes = %d", (intptr_t)chunk->length());
905
906 #ifndef PRODUCT
907 if (TraceDeoptimization) {
908 ttyLocker ttyl;
909 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
910 if (Verbose) {
911 int count = 0;
912 // this used to leak deoptimizedVFrame like it was going out of style!!!
913 for (int index = 0; index < array->frames(); index++ ) {
914 vframeArrayElement* e = array->element(index);
915 e->print(tty);
916
917 /*
918 No printing yet.
919 array->vframe_at(index)->print_activation(count++);
920 // better as...
921 array->print_activation_for(index, count++);
922 */
923 }
924 }
925 }
926 #endif // PRODUCT
927
928 return array;
929 }
930
931
932 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
933 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
934 for (int i = 0; i < monitors->length(); i++) {
935 MonitorInfo* mon_info = monitors->at(i);
936 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
937 objects_to_revoke->append(Handle(mon_info->owner()));
938 }
939 }
940 }
941
942
943 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
944 if (!UseBiasedLocking) {
945 return;
946 }
947
948 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
949
950 // Unfortunately we don't have a RegisterMap available in most of
951 // the places we want to call this routine so we need to walk the
952 // stack again to update the register map.
953 if (map == NULL || !map->update_map()) {
954 StackFrameStream sfs(thread, true);
955 bool found = false;
956 while (!found && !sfs.is_done()) {
957 frame* cur = sfs.current();
958 sfs.next();
959 found = cur->id() == fr.id();
960 }
961 assert(found, "frame to be deoptimized not found on target thread's stack");
962 map = sfs.register_map();
963 }
964
965 vframe* vf = vframe::new_vframe(&fr, map, thread);
966 compiledVFrame* cvf = compiledVFrame::cast(vf);
967 // Revoke monitors' biases in all scopes
968 while (!cvf->is_top()) {
969 collect_monitors(cvf, objects_to_revoke);
970 cvf = compiledVFrame::cast(cvf->sender());
971 }
972 collect_monitors(cvf, objects_to_revoke);
973
974 if (SafepointSynchronize::is_at_safepoint()) {
975 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
976 } else {
977 BiasedLocking::revoke(objects_to_revoke);
978 }
979 }
980
981
982 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
983 if (!UseBiasedLocking) {
984 return;
985 }
986
987 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
988 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
989 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
990 if (jt->has_last_Java_frame()) {
991 StackFrameStream sfs(jt, true);
992 while (!sfs.is_done()) {
993 frame* cur = sfs.current();
994 if (cb->contains(cur->pc())) {
995 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
996 compiledVFrame* cvf = compiledVFrame::cast(vf);
997 // Revoke monitors' biases in all scopes
998 while (!cvf->is_top()) {
999 collect_monitors(cvf, objects_to_revoke);
1000 cvf = compiledVFrame::cast(cvf->sender());
1001 }
1002 collect_monitors(cvf, objects_to_revoke);
1003 }
1004 sfs.next();
1005 }
1006 }
1007 }
1008 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1009 }
1010
1011
1012 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1013 assert(fr.can_be_deoptimized(), "checking frame type");
1014
1015 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1016
1017 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1018
1019 // Patch the nmethod so that when execution returns to it we will
1020 // deopt the execution state and return to the interpreter.
1021 fr.deoptimize(thread);
1022 }
1023
1024 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1025 // Deoptimize only if the frame comes from compile code.
1026 // Do not deoptimize the frame which is already patched
1027 // during the execution of the loops below.
1028 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1029 return;
1030 }
1031 ResourceMark rm;
1032 DeoptimizationMarker dm;
1033 if (UseBiasedLocking) {
1034 revoke_biases_of_monitors(thread, fr, map);
1035 }
1036 deoptimize_single_frame(thread, fr);
1037
1038 }
1039
1040
1041 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1042 // Compute frame and register map based on thread and sp.
1043 RegisterMap reg_map(thread, UseBiasedLocking);
1044 frame fr = thread->last_frame();
1045 while (fr.id() != id) {
1046 fr = fr.sender(®_map);
1047 }
1048 deoptimize(thread, fr, ®_map);
1049 }
1050
1051
1052 // JVMTI PopFrame support
1053 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1054 {
1055 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1056 }
1057 JRT_END
1058
1059
1060 #ifdef COMPILER2
1061 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1062 // in case of an unresolved klass entry, load the class.
1063 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1064 klassOop tk = constant_pool->klass_at(index, CHECK);
1065 return;
1066 }
1067
1068 if (!constant_pool->tag_at(index).is_symbol()) return;
1069
1070 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1071 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1072
1073 // class name?
1074 if (symbol->byte_at(0) != '(') {
1075 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1076 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1077 return;
1078 }
1079
1080 // then it must be a signature!
1081 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1082 if (ss.is_object()) {
1083 symbolOop s = ss.as_symbol(CHECK);
1084 symbolHandle class_name (THREAD, s);
1085 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1086 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1087 }
1088 }
1089 }
1090
1091
1092 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1093 EXCEPTION_MARK;
1094 load_class_by_index(constant_pool, index, THREAD);
1095 if (HAS_PENDING_EXCEPTION) {
1096 // Exception happened during classloading. We ignore the exception here, since it
1097 // is going to be rethrown since the current activation is going to be deoptimzied and
1098 // the interpreter will re-execute the bytecode.
1099 CLEAR_PENDING_EXCEPTION;
1100 }
1101 }
1102
1103 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1104 HandleMark hm;
1105
1106 // uncommon_trap() is called at the beginning of the uncommon trap
1107 // handler. Note this fact before we start generating temporary frames
1108 // that can confuse an asynchronous stack walker. This counter is
1109 // decremented at the end of unpack_frames().
1110 thread->inc_in_deopt_handler();
1111
1112 // We need to update the map if we have biased locking.
1113 RegisterMap reg_map(thread, UseBiasedLocking);
1114 frame stub_frame = thread->last_frame();
1115 frame fr = stub_frame.sender(®_map);
1116 // Make sure the calling nmethod is not getting deoptimized and removed
1117 // before we are done with it.
1118 nmethodLocker nl(fr.pc());
1119
1120 {
1121 ResourceMark rm;
1122
1123 // Revoke biases of any monitors in the frame to ensure we can migrate them
1124 revoke_biases_of_monitors(thread, fr, ®_map);
1125
1126 DeoptReason reason = trap_request_reason(trap_request);
1127 DeoptAction action = trap_request_action(trap_request);
1128 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1129
1130 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1131 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1132 compiledVFrame* cvf = compiledVFrame::cast(vf);
1133
1134 nmethod* nm = cvf->code();
1135
1136 ScopeDesc* trap_scope = cvf->scope();
1137 methodHandle trap_method = trap_scope->method();
1138 int trap_bci = trap_scope->bci();
1139 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code();
1140
1141 // Record this event in the histogram.
1142 gather_statistics(reason, action, trap_bc);
1143
1144 // Ensure that we can record deopt. history:
1145 bool create_if_missing = ProfileTraps;
1146
1147 methodDataHandle trap_mdo
1148 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1149
1150 // Print a bunch of diagnostics, if requested.
1151 if (TraceDeoptimization || LogCompilation) {
1152 ResourceMark rm;
1153 ttyLocker ttyl;
1154 char buf[100];
1155 if (xtty != NULL) {
1156 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1157 os::current_thread_id(),
1158 format_trap_request(buf, sizeof(buf), trap_request));
1159 nm->log_identity(xtty);
1160 }
1161 symbolHandle class_name;
1162 bool unresolved = false;
1163 if (unloaded_class_index >= 0) {
1164 constantPoolHandle constants (THREAD, trap_method->constants());
1165 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1166 class_name = symbolHandle(THREAD,
1167 constants->klass_name_at(unloaded_class_index));
1168 unresolved = true;
1169 if (xtty != NULL)
1170 xtty->print(" unresolved='1'");
1171 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1172 class_name = symbolHandle(THREAD,
1173 constants->symbol_at(unloaded_class_index));
1174 }
1175 if (xtty != NULL)
1176 xtty->name(class_name);
1177 }
1178 if (xtty != NULL && trap_mdo.not_null()) {
1179 // Dump the relevant MDO state.
1180 // This is the deopt count for the current reason, any previous
1181 // reasons or recompiles seen at this point.
1182 int dcnt = trap_mdo->trap_count(reason);
1183 if (dcnt != 0)
1184 xtty->print(" count='%d'", dcnt);
1185 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1186 int dos = (pdata == NULL)? 0: pdata->trap_state();
1187 if (dos != 0) {
1188 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1189 if (trap_state_is_recompiled(dos)) {
1190 int recnt2 = trap_mdo->overflow_recompile_count();
1191 if (recnt2 != 0)
1192 xtty->print(" recompiles2='%d'", recnt2);
1193 }
1194 }
1195 }
1196 if (xtty != NULL) {
1197 xtty->stamp();
1198 xtty->end_head();
1199 }
1200 if (TraceDeoptimization) { // make noise on the tty
1201 tty->print("Uncommon trap occurred in");
1202 nm->method()->print_short_name(tty);
1203 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1204 fr.pc(),
1205 (int) os::current_thread_id(),
1206 trap_reason_name(reason),
1207 trap_action_name(action),
1208 unloaded_class_index);
1209 if (class_name.not_null()) {
1210 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1211 class_name->print_symbol_on(tty);
1212 }
1213 tty->cr();
1214 }
1215 if (xtty != NULL) {
1216 // Log the precise location of the trap.
1217 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1218 xtty->begin_elem("jvms bci='%d'", sd->bci());
1219 xtty->method(sd->method());
1220 xtty->end_elem();
1221 if (sd->is_top()) break;
1222 }
1223 xtty->tail("uncommon_trap");
1224 }
1225 }
1226 // (End diagnostic printout.)
1227
1228 // Load class if necessary
1229 if (unloaded_class_index >= 0) {
1230 constantPoolHandle constants(THREAD, trap_method->constants());
1231 load_class_by_index(constants, unloaded_class_index);
1232 }
1233
1234 // Flush the nmethod if necessary and desirable.
1235 //
1236 // We need to avoid situations where we are re-flushing the nmethod
1237 // because of a hot deoptimization site. Repeated flushes at the same
1238 // point need to be detected by the compiler and avoided. If the compiler
1239 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1240 // module must take measures to avoid an infinite cycle of recompilation
1241 // and deoptimization. There are several such measures:
1242 //
1243 // 1. If a recompilation is ordered a second time at some site X
1244 // and for the same reason R, the action is adjusted to 'reinterpret',
1245 // to give the interpreter time to exercise the method more thoroughly.
1246 // If this happens, the method's overflow_recompile_count is incremented.
1247 //
1248 // 2. If the compiler fails to reduce the deoptimization rate, then
1249 // the method's overflow_recompile_count will begin to exceed the set
1250 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1251 // is adjusted to 'make_not_compilable', and the method is abandoned
1252 // to the interpreter. This is a performance hit for hot methods,
1253 // but is better than a disastrous infinite cycle of recompilations.
1254 // (Actually, only the method containing the site X is abandoned.)
1255 //
1256 // 3. In parallel with the previous measures, if the total number of
1257 // recompilations of a method exceeds the much larger set limit
1258 // PerMethodRecompilationCutoff, the method is abandoned.
1259 // This should only happen if the method is very large and has
1260 // many "lukewarm" deoptimizations. The code which enforces this
1261 // limit is elsewhere (class nmethod, class methodOopDesc).
1262 //
1263 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1264 // to recompile at each bytecode independently of the per-BCI cutoff.
1265 //
1266 // The decision to update code is up to the compiler, and is encoded
1267 // in the Action_xxx code. If the compiler requests Action_none
1268 // no trap state is changed, no compiled code is changed, and the
1269 // computation suffers along in the interpreter.
1270 //
1271 // The other action codes specify various tactics for decompilation
1272 // and recompilation. Action_maybe_recompile is the loosest, and
1273 // allows the compiled code to stay around until enough traps are seen,
1274 // and until the compiler gets around to recompiling the trapping method.
1275 //
1276 // The other actions cause immediate removal of the present code.
1277
1278 bool update_trap_state = true;
1279 bool make_not_entrant = false;
1280 bool make_not_compilable = false;
1281 bool reset_counters = false;
1282 switch (action) {
1283 case Action_none:
1284 // Keep the old code.
1285 update_trap_state = false;
1286 break;
1287 case Action_maybe_recompile:
1288 // Do not need to invalidate the present code, but we can
1289 // initiate another
1290 // Start compiler without (necessarily) invalidating the nmethod.
1291 // The system will tolerate the old code, but new code should be
1292 // generated when possible.
1293 break;
1294 case Action_reinterpret:
1295 // Go back into the interpreter for a while, and then consider
1296 // recompiling form scratch.
1297 make_not_entrant = true;
1298 // Reset invocation counter for outer most method.
1299 // This will allow the interpreter to exercise the bytecodes
1300 // for a while before recompiling.
1301 // By contrast, Action_make_not_entrant is immediate.
1302 //
1303 // Note that the compiler will track null_check, null_assert,
1304 // range_check, and class_check events and log them as if they
1305 // had been traps taken from compiled code. This will update
1306 // the MDO trap history so that the next compilation will
1307 // properly detect hot trap sites.
1308 reset_counters = true;
1309 break;
1310 case Action_make_not_entrant:
1311 // Request immediate recompilation, and get rid of the old code.
1312 // Make them not entrant, so next time they are called they get
1313 // recompiled. Unloaded classes are loaded now so recompile before next
1314 // time they are called. Same for uninitialized. The interpreter will
1315 // link the missing class, if any.
1316 make_not_entrant = true;
1317 break;
1318 case Action_make_not_compilable:
1319 // Give up on compiling this method at all.
1320 make_not_entrant = true;
1321 make_not_compilable = true;
1322 break;
1323 default:
1324 ShouldNotReachHere();
1325 }
1326
1327 // Setting +ProfileTraps fixes the following, on all platforms:
1328 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1329 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1330 // recompile relies on a methodDataOop to record heroic opt failures.
1331
1332 // Whether the interpreter is producing MDO data or not, we also need
1333 // to use the MDO to detect hot deoptimization points and control
1334 // aggressive optimization.
1335 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1336 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1337 uint this_trap_count = 0;
1338 bool maybe_prior_trap = false;
1339 bool maybe_prior_recompile = false;
1340 ProfileData* pdata
1341 = query_update_method_data(trap_mdo, trap_bci, reason,
1342 //outputs:
1343 this_trap_count,
1344 maybe_prior_trap,
1345 maybe_prior_recompile);
1346 // Because the interpreter also counts null, div0, range, and class
1347 // checks, these traps from compiled code are double-counted.
1348 // This is harmless; it just means that the PerXTrapLimit values
1349 // are in effect a little smaller than they look.
1350
1351 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1352 if (per_bc_reason != Reason_none) {
1353 // Now take action based on the partially known per-BCI history.
1354 if (maybe_prior_trap
1355 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1356 // If there are too many traps at this BCI, force a recompile.
1357 // This will allow the compiler to see the limit overflow, and
1358 // take corrective action, if possible. The compiler generally
1359 // does not use the exact PerBytecodeTrapLimit value, but instead
1360 // changes its tactics if it sees any traps at all. This provides
1361 // a little hysteresis, delaying a recompile until a trap happens
1362 // several times.
1363 //
1364 // Actually, since there is only one bit of counter per BCI,
1365 // the possible per-BCI counts are {0,1,(per-method count)}.
1366 // This produces accurate results if in fact there is only
1367 // one hot trap site, but begins to get fuzzy if there are
1368 // many sites. For example, if there are ten sites each
1369 // trapping two or more times, they each get the blame for
1370 // all of their traps.
1371 make_not_entrant = true;
1372 }
1373
1374 // Detect repeated recompilation at the same BCI, and enforce a limit.
1375 if (make_not_entrant && maybe_prior_recompile) {
1376 // More than one recompile at this point.
1377 trap_mdo->inc_overflow_recompile_count();
1378 if (maybe_prior_trap
1379 && ((uint)trap_mdo->overflow_recompile_count()
1380 > (uint)PerBytecodeRecompilationCutoff)) {
1381 // Give up on the method containing the bad BCI.
1382 if (trap_method() == nm->method()) {
1383 make_not_compilable = true;
1384 } else {
1385 trap_method->set_not_compilable();
1386 // But give grace to the enclosing nm->method().
1387 }
1388 }
1389 }
1390 } else {
1391 // For reasons which are not recorded per-bytecode, we simply
1392 // force recompiles unconditionally.
1393 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1394 make_not_entrant = true;
1395 }
1396
1397 // Go back to the compiler if there are too many traps in this method.
1398 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1399 // If there are too many traps in this method, force a recompile.
1400 // This will allow the compiler to see the limit overflow, and
1401 // take corrective action, if possible.
1402 // (This condition is an unlikely backstop only, because the
1403 // PerBytecodeTrapLimit is more likely to take effect first,
1404 // if it is applicable.)
1405 make_not_entrant = true;
1406 }
1407
1408 // Here's more hysteresis: If there has been a recompile at
1409 // this trap point already, run the method in the interpreter
1410 // for a while to exercise it more thoroughly.
1411 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1412 reset_counters = true;
1413 }
1414
1415 if (make_not_entrant && pdata != NULL) {
1416 // Record the recompilation event, if any.
1417 int tstate0 = pdata->trap_state();
1418 int tstate1 = trap_state_set_recompiled(tstate0, true);
1419 if (tstate1 != tstate0)
1420 pdata->set_trap_state(tstate1);
1421 }
1422 }
1423
1424 // Take requested actions on the method:
1425
1426 // Reset invocation counters
1427 if (reset_counters) {
1428 if (nm->is_osr_method())
1429 reset_invocation_counter(trap_scope, CompileThreshold);
1430 else
1431 reset_invocation_counter(trap_scope);
1432 }
1433
1434 // Recompile
1435 if (make_not_entrant) {
1436 nm->make_not_entrant();
1437 }
1438
1439 // Give up compiling
1440 if (make_not_compilable) {
1441 assert(make_not_entrant, "consistent");
1442 nm->method()->set_not_compilable();
1443 }
1444
1445 } // Free marked resources
1446
1447 }
1448 JRT_END
1449
1450 methodDataOop
1451 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1452 bool create_if_missing) {
1453 Thread* THREAD = thread;
1454 methodDataOop mdo = m()->method_data();
1455 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1456 // Build an MDO. Ignore errors like OutOfMemory;
1457 // that simply means we won't have an MDO to update.
1458 methodOopDesc::build_interpreter_method_data(m, THREAD);
1459 if (HAS_PENDING_EXCEPTION) {
1460 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1461 CLEAR_PENDING_EXCEPTION;
1462 }
1463 mdo = m()->method_data();
1464 }
1465 return mdo;
1466 }
1467
1468 ProfileData*
1469 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1470 int trap_bci,
1471 Deoptimization::DeoptReason reason,
1472 //outputs:
1473 uint& ret_this_trap_count,
1474 bool& ret_maybe_prior_trap,
1475 bool& ret_maybe_prior_recompile) {
1476 uint prior_trap_count = trap_mdo->trap_count(reason);
1477 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1478
1479 // If the runtime cannot find a place to store trap history,
1480 // it is estimated based on the general condition of the method.
1481 // If the method has ever been recompiled, or has ever incurred
1482 // a trap with the present reason , then this BCI is assumed
1483 // (pessimistically) to be the culprit.
1484 bool maybe_prior_trap = (prior_trap_count != 0);
1485 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1486 ProfileData* pdata = NULL;
1487
1488
1489 // For reasons which are recorded per bytecode, we check per-BCI data.
1490 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1491 if (per_bc_reason != Reason_none) {
1492 // Find the profile data for this BCI. If there isn't one,
1493 // try to allocate one from the MDO's set of spares.
1494 // This will let us detect a repeated trap at this point.
1495 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1496
1497 if (pdata != NULL) {
1498 // Query the trap state of this profile datum.
1499 int tstate0 = pdata->trap_state();
1500 if (!trap_state_has_reason(tstate0, per_bc_reason))
1501 maybe_prior_trap = false;
1502 if (!trap_state_is_recompiled(tstate0))
1503 maybe_prior_recompile = false;
1504
1505 // Update the trap state of this profile datum.
1506 int tstate1 = tstate0;
1507 // Record the reason.
1508 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1509 // Store the updated state on the MDO, for next time.
1510 if (tstate1 != tstate0)
1511 pdata->set_trap_state(tstate1);
1512 } else {
1513 if (LogCompilation && xtty != NULL)
1514 // Missing MDP? Leave a small complaint in the log.
1515 xtty->elem("missing_mdp bci='%d'", trap_bci);
1516 }
1517 }
1518
1519 // Return results:
1520 ret_this_trap_count = this_trap_count;
1521 ret_maybe_prior_trap = maybe_prior_trap;
1522 ret_maybe_prior_recompile = maybe_prior_recompile;
1523 return pdata;
1524 }
1525
1526 void
1527 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1528 ResourceMark rm;
1529 // Ignored outputs:
1530 uint ignore_this_trap_count;
1531 bool ignore_maybe_prior_trap;
1532 bool ignore_maybe_prior_recompile;
1533 query_update_method_data(trap_mdo, trap_bci,
1534 (DeoptReason)reason,
1535 ignore_this_trap_count,
1536 ignore_maybe_prior_trap,
1537 ignore_maybe_prior_recompile);
1538 }
1539
1540 void Deoptimization::reset_invocation_counter(ScopeDesc* trap_scope, jint top_count) {
1541 ScopeDesc* sd = trap_scope;
1542 for (; !sd->is_top(); sd = sd->sender()) {
1543 // Reset ICs of inlined methods, since they can trigger compilations also.
1544 sd->method()->invocation_counter()->reset();
1545 }
1546 InvocationCounter* c = sd->method()->invocation_counter();
1547 if (top_count != _no_count) {
1548 // It was an OSR method, so bump the count higher.
1549 c->set(c->state(), top_count);
1550 } else {
1551 c->reset();
1552 }
1553 sd->method()->backedge_counter()->reset();
1554 }
1555
1556 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1557
1558 // Still in Java no safepoints
1559 {
1560 // This enters VM and may safepoint
1561 uncommon_trap_inner(thread, trap_request);
1562 }
1563 return fetch_unroll_info_helper(thread);
1564 }
1565
1566 // Local derived constants.
1567 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1568 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1569 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1570
1571 //---------------------------trap_state_reason---------------------------------
1572 Deoptimization::DeoptReason
1573 Deoptimization::trap_state_reason(int trap_state) {
1574 // This assert provides the link between the width of DataLayout::trap_bits
1575 // and the encoding of "recorded" reasons. It ensures there are enough
1576 // bits to store all needed reasons in the per-BCI MDO profile.
1577 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1578 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1579 trap_state -= recompile_bit;
1580 if (trap_state == DS_REASON_MASK) {
1581 return Reason_many;
1582 } else {
1583 assert((int)Reason_none == 0, "state=0 => Reason_none");
1584 return (DeoptReason)trap_state;
1585 }
1586 }
1587 //-------------------------trap_state_has_reason-------------------------------
1588 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1589 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1590 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1591 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1592 trap_state -= recompile_bit;
1593 if (trap_state == DS_REASON_MASK) {
1594 return -1; // true, unspecifically (bottom of state lattice)
1595 } else if (trap_state == reason) {
1596 return 1; // true, definitely
1597 } else if (trap_state == 0) {
1598 return 0; // false, definitely (top of state lattice)
1599 } else {
1600 return 0; // false, definitely
1601 }
1602 }
1603 //-------------------------trap_state_add_reason-------------------------------
1604 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1605 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1606 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1607 trap_state -= recompile_bit;
1608 if (trap_state == DS_REASON_MASK) {
1609 return trap_state + recompile_bit; // already at state lattice bottom
1610 } else if (trap_state == reason) {
1611 return trap_state + recompile_bit; // the condition is already true
1612 } else if (trap_state == 0) {
1613 return reason + recompile_bit; // no condition has yet been true
1614 } else {
1615 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1616 }
1617 }
1618 //-----------------------trap_state_is_recompiled------------------------------
1619 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1620 return (trap_state & DS_RECOMPILE_BIT) != 0;
1621 }
1622 //-----------------------trap_state_set_recompiled-----------------------------
1623 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1624 if (z) return trap_state | DS_RECOMPILE_BIT;
1625 else return trap_state & ~DS_RECOMPILE_BIT;
1626 }
1627 //---------------------------format_trap_state---------------------------------
1628 // This is used for debugging and diagnostics, including hotspot.log output.
1629 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1630 int trap_state) {
1631 DeoptReason reason = trap_state_reason(trap_state);
1632 bool recomp_flag = trap_state_is_recompiled(trap_state);
1633 // Re-encode the state from its decoded components.
1634 int decoded_state = 0;
1635 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1636 decoded_state = trap_state_add_reason(decoded_state, reason);
1637 if (recomp_flag)
1638 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1639 // If the state re-encodes properly, format it symbolically.
1640 // Because this routine is used for debugging and diagnostics,
1641 // be robust even if the state is a strange value.
1642 size_t len;
1643 if (decoded_state != trap_state) {
1644 // Random buggy state that doesn't decode??
1645 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1646 } else {
1647 len = jio_snprintf(buf, buflen, "%s%s",
1648 trap_reason_name(reason),
1649 recomp_flag ? " recompiled" : "");
1650 }
1651 if (len >= buflen)
1652 buf[buflen-1] = '\0';
1653 return buf;
1654 }
1655
1656
1657 //--------------------------------statics--------------------------------------
1658 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1659 = Deoptimization::Action_reinterpret;
1660 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1661 // Note: Keep this in sync. with enum DeoptReason.
1662 "none",
1663 "null_check",
1664 "null_assert",
1665 "range_check",
1666 "class_check",
1667 "array_check",
1668 "intrinsic",
1669 "unloaded",
1670 "uninitialized",
1671 "unreached",
1672 "unhandled",
1673 "constraint",
1674 "div0_check",
1675 "age",
1676 "predicate"
1677 };
1678 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1679 // Note: Keep this in sync. with enum DeoptAction.
1680 "none",
1681 "maybe_recompile",
1682 "reinterpret",
1683 "make_not_entrant",
1684 "make_not_compilable"
1685 };
1686
1687 const char* Deoptimization::trap_reason_name(int reason) {
1688 if (reason == Reason_many) return "many";
1689 if ((uint)reason < Reason_LIMIT)
1690 return _trap_reason_name[reason];
1691 static char buf[20];
1692 sprintf(buf, "reason%d", reason);
1693 return buf;
1694 }
1695 const char* Deoptimization::trap_action_name(int action) {
1696 if ((uint)action < Action_LIMIT)
1697 return _trap_action_name[action];
1698 static char buf[20];
1699 sprintf(buf, "action%d", action);
1700 return buf;
1701 }
1702
1703 // This is used for debugging and diagnostics, including hotspot.log output.
1704 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1705 int trap_request) {
1706 jint unloaded_class_index = trap_request_index(trap_request);
1707 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1708 const char* action = trap_action_name(trap_request_action(trap_request));
1709 size_t len;
1710 if (unloaded_class_index < 0) {
1711 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1712 reason, action);
1713 } else {
1714 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1715 reason, action, unloaded_class_index);
1716 }
1717 if (len >= buflen)
1718 buf[buflen-1] = '\0';
1719 return buf;
1720 }
1721
1722 juint Deoptimization::_deoptimization_hist
1723 [Deoptimization::Reason_LIMIT]
1724 [1 + Deoptimization::Action_LIMIT]
1725 [Deoptimization::BC_CASE_LIMIT]
1726 = {0};
1727
1728 enum {
1729 LSB_BITS = 8,
1730 LSB_MASK = right_n_bits(LSB_BITS)
1731 };
1732
1733 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1734 Bytecodes::Code bc) {
1735 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1736 assert(action >= 0 && action < Action_LIMIT, "oob");
1737 _deoptimization_hist[Reason_none][0][0] += 1; // total
1738 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1739 juint* cases = _deoptimization_hist[reason][1+action];
1740 juint* bc_counter_addr = NULL;
1741 juint bc_counter = 0;
1742 // Look for an unused counter, or an exact match to this BC.
1743 if (bc != Bytecodes::_illegal) {
1744 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1745 juint* counter_addr = &cases[bc_case];
1746 juint counter = *counter_addr;
1747 if ((counter == 0 && bc_counter_addr == NULL)
1748 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1749 // this counter is either free or is already devoted to this BC
1750 bc_counter_addr = counter_addr;
1751 bc_counter = counter | bc;
1752 }
1753 }
1754 }
1755 if (bc_counter_addr == NULL) {
1756 // Overflow, or no given bytecode.
1757 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1758 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1759 }
1760 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1761 }
1762
1763 jint Deoptimization::total_deoptimization_count() {
1764 return _deoptimization_hist[Reason_none][0][0];
1765 }
1766
1767 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1768 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1769 return _deoptimization_hist[reason][0][0];
1770 }
1771
1772 void Deoptimization::print_statistics() {
1773 juint total = total_deoptimization_count();
1774 juint account = total;
1775 if (total != 0) {
1776 ttyLocker ttyl;
1777 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1778 tty->print_cr("Deoptimization traps recorded:");
1779 #define PRINT_STAT_LINE(name, r) \
1780 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1781 PRINT_STAT_LINE("total", total);
1782 // For each non-zero entry in the histogram, print the reason,
1783 // the action, and (if specifically known) the type of bytecode.
1784 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1785 for (int action = 0; action < Action_LIMIT; action++) {
1786 juint* cases = _deoptimization_hist[reason][1+action];
1787 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1788 juint counter = cases[bc_case];
1789 if (counter != 0) {
1790 char name[1*K];
1791 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1792 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1793 bc = Bytecodes::_illegal;
1794 sprintf(name, "%s/%s/%s",
1795 trap_reason_name(reason),
1796 trap_action_name(action),
1797 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1798 juint r = counter >> LSB_BITS;
1799 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1800 account -= r;
1801 }
1802 }
1803 }
1804 }
1805 if (account != 0) {
1806 PRINT_STAT_LINE("unaccounted", account);
1807 }
1808 #undef PRINT_STAT_LINE
1809 if (xtty != NULL) xtty->tail("statistics");
1810 }
1811 }
1812 #else // COMPILER2
1813
1814
1815 // Stubs for C1 only system.
1816 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1817 return false;
1818 }
1819
1820 const char* Deoptimization::trap_reason_name(int reason) {
1821 return "unknown";
1822 }
1823
1824 void Deoptimization::print_statistics() {
1825 // no output
1826 }
1827
1828 void
1829 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1830 // no udpate
1831 }
1832
1833 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1834 return 0;
1835 }
1836
1837 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1838 Bytecodes::Code bc) {
1839 // no update
1840 }
1841
1842 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1843 int trap_state) {
1844 jio_snprintf(buf, buflen, "#%d", trap_state);
1845 return buf;
1846 }
1847
1848 #endif // COMPILER2