1 /*
2 * Copyright 1997-2010 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 // If the deopt call site is a MethodHandle invoke call site we have
239 // to adjust the unpack_sp.
240 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
241 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
242 unpack_sp = deoptee.unextended_sp();
243
244 #ifdef ASSERT
245 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
246 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
247 #endif
248 // This is a guarantee instead of an assert because if vframe doesn't match
249 // we will unpack the wrong deoptimized frame and wind up in strange places
250 // where it will be very difficult to figure out what went wrong. Better
251 // to die an early death here than some very obscure death later when the
252 // trail is cold.
253 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
254 // in that it will fail to detect a problem when there is one. This needs
255 // more work in tiger timeframe.
256 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
257
258 int number_of_frames = array->frames();
259
260 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
261 // virtual activation, which is the reverse of the elements in the vframes array.
262 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
263 // +1 because we always have an interpreter return address for the final slot.
264 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
265 int callee_parameters = 0;
266 int callee_locals = 0;
267 int popframe_extra_args = 0;
268 // Create an interpreter return address for the stub to use as its return
269 // address so the skeletal frames are perfectly walkable
270 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
271
272 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
273 // activation be put back on the expression stack of the caller for reexecution
274 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
275 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
276 }
277
278 //
279 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
280 // frame_sizes/frame_pcs[1] next oldest frame (int)
281 // frame_sizes/frame_pcs[n] youngest frame (int)
282 //
283 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
284 // owns the space for the return address to it's caller). Confusing ain't it.
285 //
286 // The vframe array can address vframes with indices running from
287 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
288 // When we create the skeletal frames we need the oldest frame to be in the zero slot
289 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
290 // so things look a little strange in this loop.
291 //
292 for (int index = 0; index < array->frames(); index++ ) {
293 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
294 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
295 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
296 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
297 callee_locals,
298 index == 0,
299 popframe_extra_args);
300 // This pc doesn't have to be perfect just good enough to identify the frame
301 // as interpreted so the skeleton frame will be walkable
302 // The correct pc will be set when the skeleton frame is completely filled out
303 // The final pc we store in the loop is wrong and will be overwritten below
304 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
305
306 callee_parameters = array->element(index)->method()->size_of_parameters();
307 callee_locals = array->element(index)->method()->max_locals();
308 popframe_extra_args = 0;
309 }
310
311 // Compute whether the root vframe returns a float or double value.
312 BasicType return_type;
313 {
314 HandleMark hm;
315 methodHandle method(thread, array->element(0)->method());
316 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci());
317 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL;
318 }
319
320 // Compute information for handling adapters and adjusting the frame size of the caller.
321 int caller_adjustment = 0;
322
323 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
324 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
325 // than simply use array->sender.pc(). This requires us to walk the current set of frames
326 //
327 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
328 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
329
330 // Compute the amount the oldest interpreter frame will have to adjust
331 // its caller's stack by. If the caller is a compiled frame then
332 // we pretend that the callee has no parameters so that the
333 // extension counts for the full amount of locals and not just
334 // locals-parms. This is because without a c2i adapter the parm
335 // area as created by the compiled frame will not be usable by
336 // the interpreter. (Depending on the calling convention there
337 // may not even be enough space).
338
339 // QQQ I'd rather see this pushed down into last_frame_adjust
340 // and have it take the sender (aka caller).
341
342 if (deopt_sender.is_compiled_frame()) {
343 caller_adjustment = last_frame_adjust(0, callee_locals);
344 } else if (callee_locals > callee_parameters) {
345 // The caller frame may need extending to accommodate
346 // non-parameter locals of the first unpacked interpreted frame.
347 // Compute that adjustment.
348 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
349 }
350
351
352 // If the sender is deoptimized the we must retrieve the address of the handler
353 // since the frame will "magically" show the original pc before the deopt
354 // and we'd undo the deopt.
355
356 frame_pcs[0] = deopt_sender.raw_pc();
357
358 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
359
360 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
361 caller_adjustment * BytesPerWord,
362 number_of_frames,
363 frame_sizes,
364 frame_pcs,
365 return_type);
366 #if defined(IA32) || defined(AMD64)
367 // We need a way to pass fp to the unpacking code so the skeletal frames
368 // come out correct. This is only needed for x86 because of c2 using ebp
369 // as an allocatable register. So this update is useless (and harmless)
370 // on the other platforms. It would be nice to do this in a different
371 // way but even the old style deoptimization had a problem with deriving
372 // this value. NEEDS_CLEANUP
373 // Note: now that c1 is using c2's deopt blob we must do this on all
374 // x86 based platforms
375 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
376 *fp_addr = array->sender().fp(); // was adapter_caller
377 #endif /* IA32 || AMD64 */
378
379 if (array->frames() > 1) {
380 if (VerifyStack && TraceDeoptimization) {
381 tty->print_cr("Deoptimizing method containing inlining");
382 }
383 }
384
385 array->set_unroll_block(info);
386 return info;
387 }
388
389 // Called to cleanup deoptimization data structures in normal case
390 // after unpacking to stack and when stack overflow error occurs
391 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
392 vframeArray *array) {
393
394 // Get array if coming from exception
395 if (array == NULL) {
396 array = thread->vframe_array_head();
397 }
398 thread->set_vframe_array_head(NULL);
399
400 // Free the previous UnrollBlock
401 vframeArray* old_array = thread->vframe_array_last();
402 thread->set_vframe_array_last(array);
403
404 if (old_array != NULL) {
405 UnrollBlock* old_info = old_array->unroll_block();
406 old_array->set_unroll_block(NULL);
407 delete old_info;
408 delete old_array;
409 }
410
411 // Deallocate any resource creating in this routine and any ResourceObjs allocated
412 // inside the vframeArray (StackValueCollections)
413
414 delete thread->deopt_mark();
415 thread->set_deopt_mark(NULL);
416
417
418 if (JvmtiExport::can_pop_frame()) {
419 #ifndef CC_INTERP
420 // Regardless of whether we entered this routine with the pending
421 // popframe condition bit set, we should always clear it now
422 thread->clear_popframe_condition();
423 #else
424 // C++ interpeter will clear has_pending_popframe when it enters
425 // with method_resume. For deopt_resume2 we clear it now.
426 if (thread->popframe_forcing_deopt_reexecution())
427 thread->clear_popframe_condition();
428 #endif /* CC_INTERP */
429 }
430
431 // unpack_frames() is called at the end of the deoptimization handler
432 // and (in C2) at the end of the uncommon trap handler. Note this fact
433 // so that an asynchronous stack walker can work again. This counter is
434 // incremented at the beginning of fetch_unroll_info() and (in C2) at
435 // the beginning of uncommon_trap().
436 thread->dec_in_deopt_handler();
437 }
438
439
440 // Return BasicType of value being returned
441 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
442
443 // We are already active int he special DeoptResourceMark any ResourceObj's we
444 // allocate will be freed at the end of the routine.
445
446 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
447 // but makes the entry a little slower. There is however a little dance we have to
448 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
449 ResetNoHandleMark rnhm; // No-op in release/product versions
450 HandleMark hm;
451
452 frame stub_frame = thread->last_frame();
453
454 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
455 // must point to the vframeArray for the unpack frame.
456 vframeArray* array = thread->vframe_array_head();
457
458 #ifndef PRODUCT
459 if (TraceDeoptimization) {
460 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
461 }
462 #endif
463
464 UnrollBlock* info = array->unroll_block();
465
466 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
467 array->unpack_to_stack(stub_frame, exec_mode);
468
469 BasicType bt = info->return_type();
470
471 // If we have an exception pending, claim that the return type is an oop
472 // so the deopt_blob does not overwrite the exception_oop.
473
474 if (exec_mode == Unpack_exception)
475 bt = T_OBJECT;
476
477 // Cleanup thread deopt data
478 cleanup_deopt_info(thread, array);
479
480 #ifndef PRODUCT
481 if (VerifyStack) {
482 ResourceMark res_mark;
483
484 // Verify that the just-unpacked frames match the interpreter's
485 // notions of expression stack and locals
486 vframeArray* cur_array = thread->vframe_array_last();
487 RegisterMap rm(thread, false);
488 rm.set_include_argument_oops(false);
489 bool is_top_frame = true;
490 int callee_size_of_parameters = 0;
491 int callee_max_locals = 0;
492 for (int i = 0; i < cur_array->frames(); i++) {
493 vframeArrayElement* el = cur_array->element(i);
494 frame* iframe = el->iframe();
495 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
496
497 // Get the oop map for this bci
498 InterpreterOopMap mask;
499 int cur_invoke_parameter_size = 0;
500 bool try_next_mask = false;
501 int next_mask_expression_stack_size = -1;
502 int top_frame_expression_stack_adjustment = 0;
503 methodHandle mh(thread, iframe->interpreter_frame_method());
504 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
505 BytecodeStream str(mh);
506 str.set_start(iframe->interpreter_frame_bci());
507 int max_bci = mh->code_size();
508 // Get to the next bytecode if possible
509 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
510 // Check to see if we can grab the number of outgoing arguments
511 // at an uncommon trap for an invoke (where the compiler
512 // generates debug info before the invoke has executed)
513 Bytecodes::Code cur_code = str.next();
514 if (cur_code == Bytecodes::_invokevirtual ||
515 cur_code == Bytecodes::_invokespecial ||
516 cur_code == Bytecodes::_invokestatic ||
517 cur_code == Bytecodes::_invokeinterface) {
518 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci());
519 symbolHandle signature(thread, invoke->signature());
520 ArgumentSizeComputer asc(signature);
521 cur_invoke_parameter_size = asc.size();
522 if (cur_code != Bytecodes::_invokestatic) {
523 // Add in receiver
524 ++cur_invoke_parameter_size;
525 }
526 }
527 if (str.bci() < max_bci) {
528 Bytecodes::Code bc = str.next();
529 if (bc >= 0) {
530 // The interpreter oop map generator reports results before
531 // the current bytecode has executed except in the case of
532 // calls. It seems to be hard to tell whether the compiler
533 // has emitted debug information matching the "state before"
534 // a given bytecode or the state after, so we try both
535 switch (cur_code) {
536 case Bytecodes::_invokevirtual:
537 case Bytecodes::_invokespecial:
538 case Bytecodes::_invokestatic:
539 case Bytecodes::_invokeinterface:
540 case Bytecodes::_athrow:
541 break;
542 default: {
543 InterpreterOopMap next_mask;
544 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
545 next_mask_expression_stack_size = next_mask.expression_stack_size();
546 // Need to subtract off the size of the result type of
547 // the bytecode because this is not described in the
548 // debug info but returned to the interpreter in the TOS
549 // caching register
550 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
551 if (bytecode_result_type != T_ILLEGAL) {
552 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
553 }
554 assert(top_frame_expression_stack_adjustment >= 0, "");
555 try_next_mask = true;
556 break;
557 }
558 }
559 }
560 }
561
562 // Verify stack depth and oops in frame
563 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
564 if (!(
565 /* SPARC */
566 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
567 /* x86 */
568 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
569 (try_next_mask &&
570 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
571 top_frame_expression_stack_adjustment))) ||
572 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
573 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
574 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
575 )) {
576 ttyLocker ttyl;
577
578 // Print out some information that will help us debug the problem
579 tty->print_cr("Wrong number of expression stack elements during deoptimization");
580 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
581 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
582 iframe->interpreter_frame_expression_stack_size());
583 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
584 tty->print_cr(" try_next_mask = %d", try_next_mask);
585 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
586 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
587 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
588 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
589 tty->print_cr(" exec_mode = %d", exec_mode);
590 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
591 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
592 tty->print_cr(" Interpreted frames:");
593 for (int k = 0; k < cur_array->frames(); k++) {
594 vframeArrayElement* el = cur_array->element(k);
595 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
596 }
597 cur_array->print_on_2(tty);
598 guarantee(false, "wrong number of expression stack elements during deopt");
599 }
600 VerifyOopClosure verify;
601 iframe->oops_interpreted_do(&verify, &rm, false);
602 callee_size_of_parameters = mh->size_of_parameters();
603 callee_max_locals = mh->max_locals();
604 is_top_frame = false;
605 }
606 }
607 #endif /* !PRODUCT */
608
609
610 return bt;
611 JRT_END
612
613
614 int Deoptimization::deoptimize_dependents() {
615 Threads::deoptimized_wrt_marked_nmethods();
616 return 0;
617 }
618
619
620 #ifdef COMPILER2
621 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
622 Handle pending_exception(thread->pending_exception());
623 const char* exception_file = thread->exception_file();
624 int exception_line = thread->exception_line();
625 thread->clear_pending_exception();
626
627 for (int i = 0; i < objects->length(); i++) {
628 assert(objects->at(i)->is_object(), "invalid debug information");
629 ObjectValue* sv = (ObjectValue*) objects->at(i);
630
631 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
632 oop obj = NULL;
633
634 if (k->oop_is_instance()) {
635 instanceKlass* ik = instanceKlass::cast(k());
636 obj = ik->allocate_instance(CHECK_(false));
637 } else if (k->oop_is_typeArray()) {
638 typeArrayKlass* ak = typeArrayKlass::cast(k());
639 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
640 int len = sv->field_size() / type2size[ak->element_type()];
641 obj = ak->allocate(len, CHECK_(false));
642 } else if (k->oop_is_objArray()) {
643 objArrayKlass* ak = objArrayKlass::cast(k());
644 obj = ak->allocate(sv->field_size(), CHECK_(false));
645 }
646
647 assert(obj != NULL, "allocation failed");
648 assert(sv->value().is_null(), "redundant reallocation");
649 sv->set_value(obj);
650 }
651
652 if (pending_exception.not_null()) {
653 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
654 }
655
656 return true;
657 }
658
659 // This assumes that the fields are stored in ObjectValue in the same order
660 // they are yielded by do_nonstatic_fields.
661 class FieldReassigner: public FieldClosure {
662 frame* _fr;
663 RegisterMap* _reg_map;
664 ObjectValue* _sv;
665 instanceKlass* _ik;
666 oop _obj;
667
668 int _i;
669 public:
670 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
671 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
672
673 int i() const { return _i; }
674
675
676 void do_field(fieldDescriptor* fd) {
677 intptr_t val;
678 StackValue* value =
679 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
680 int offset = fd->offset();
681 switch (fd->field_type()) {
682 case T_OBJECT: case T_ARRAY:
683 assert(value->type() == T_OBJECT, "Agreement.");
684 _obj->obj_field_put(offset, value->get_obj()());
685 break;
686
687 case T_LONG: case T_DOUBLE: {
688 assert(value->type() == T_INT, "Agreement.");
689 StackValue* low =
690 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
691 #ifdef _LP64
692 jlong res = (jlong)low->get_int();
693 #else
694 #ifdef SPARC
695 // For SPARC we have to swap high and low words.
696 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
697 #else
698 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
699 #endif //SPARC
700 #endif
701 _obj->long_field_put(offset, res);
702 break;
703 }
704 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
705 case T_INT: case T_FLOAT: // 4 bytes.
706 assert(value->type() == T_INT, "Agreement.");
707 val = value->get_int();
708 _obj->int_field_put(offset, (jint)*((jint*)&val));
709 break;
710
711 case T_SHORT: case T_CHAR: // 2 bytes
712 assert(value->type() == T_INT, "Agreement.");
713 val = value->get_int();
714 _obj->short_field_put(offset, (jshort)*((jint*)&val));
715 break;
716
717 case T_BOOLEAN: case T_BYTE: // 1 byte
718 assert(value->type() == T_INT, "Agreement.");
719 val = value->get_int();
720 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
721 break;
722
723 default:
724 ShouldNotReachHere();
725 }
726 _i++;
727 }
728 };
729
730 // restore elements of an eliminated type array
731 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
732 int index = 0;
733 intptr_t val;
734
735 for (int i = 0; i < sv->field_size(); i++) {
736 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
737 switch(type) {
738 case T_LONG: case T_DOUBLE: {
739 assert(value->type() == T_INT, "Agreement.");
740 StackValue* low =
741 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
742 #ifdef _LP64
743 jlong res = (jlong)low->get_int();
744 #else
745 #ifdef SPARC
746 // For SPARC we have to swap high and low words.
747 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
748 #else
749 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
750 #endif //SPARC
751 #endif
752 obj->long_at_put(index, res);
753 break;
754 }
755
756 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
757 case T_INT: case T_FLOAT: // 4 bytes.
758 assert(value->type() == T_INT, "Agreement.");
759 val = value->get_int();
760 obj->int_at_put(index, (jint)*((jint*)&val));
761 break;
762
763 case T_SHORT: case T_CHAR: // 2 bytes
764 assert(value->type() == T_INT, "Agreement.");
765 val = value->get_int();
766 obj->short_at_put(index, (jshort)*((jint*)&val));
767 break;
768
769 case T_BOOLEAN: case T_BYTE: // 1 byte
770 assert(value->type() == T_INT, "Agreement.");
771 val = value->get_int();
772 obj->bool_at_put(index, (jboolean)*((jint*)&val));
773 break;
774
775 default:
776 ShouldNotReachHere();
777 }
778 index++;
779 }
780 }
781
782
783 // restore fields of an eliminated object array
784 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
785 for (int i = 0; i < sv->field_size(); i++) {
786 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
787 assert(value->type() == T_OBJECT, "object element expected");
788 obj->obj_at_put(i, value->get_obj()());
789 }
790 }
791
792
793 // restore fields of all eliminated objects and arrays
794 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
795 for (int i = 0; i < objects->length(); i++) {
796 ObjectValue* sv = (ObjectValue*) objects->at(i);
797 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
798 Handle obj = sv->value();
799 assert(obj.not_null(), "reallocation was missed");
800
801 if (k->oop_is_instance()) {
802 instanceKlass* ik = instanceKlass::cast(k());
803 FieldReassigner reassign(fr, reg_map, sv, obj());
804 ik->do_nonstatic_fields(&reassign);
805 } else if (k->oop_is_typeArray()) {
806 typeArrayKlass* ak = typeArrayKlass::cast(k());
807 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
808 } else if (k->oop_is_objArray()) {
809 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
810 }
811 }
812 }
813
814
815 // relock objects for which synchronization was eliminated
816 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
817 for (int i = 0; i < monitors->length(); i++) {
818 MonitorInfo* mon_info = monitors->at(i);
819 if (mon_info->eliminated()) {
820 assert(mon_info->owner() != NULL, "reallocation was missed");
821 Handle obj = Handle(mon_info->owner());
822 markOop mark = obj->mark();
823 if (UseBiasedLocking && mark->has_bias_pattern()) {
824 // New allocated objects may have the mark set to anonymously biased.
825 // Also the deoptimized method may called methods with synchronization
826 // where the thread-local object is bias locked to the current thread.
827 assert(mark->is_biased_anonymously() ||
828 mark->biased_locker() == thread, "should be locked to current thread");
829 // Reset mark word to unbiased prototype.
830 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
831 obj->set_mark(unbiased_prototype);
832 }
833 BasicLock* lock = mon_info->lock();
834 ObjectSynchronizer::slow_enter(obj, lock, thread);
835 }
836 assert(mon_info->owner()->is_locked(), "object must be locked now");
837 }
838 }
839
840
841 #ifndef PRODUCT
842 // print information about reallocated objects
843 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
844 fieldDescriptor fd;
845
846 for (int i = 0; i < objects->length(); i++) {
847 ObjectValue* sv = (ObjectValue*) objects->at(i);
848 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
849 Handle obj = sv->value();
850
851 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
852 k->as_klassOop()->print_value();
853 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
854 tty->cr();
855
856 if (Verbose) {
857 k->oop_print_on(obj(), tty);
858 }
859 }
860 }
861 #endif
862 #endif // COMPILER2
863
864 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
865
866 #ifndef PRODUCT
867 if (TraceDeoptimization) {
868 ttyLocker ttyl;
869 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
870 fr.print_on(tty);
871 tty->print_cr(" Virtual frames (innermost first):");
872 for (int index = 0; index < chunk->length(); index++) {
873 compiledVFrame* vf = chunk->at(index);
874 tty->print(" %2d - ", index);
875 vf->print_value();
876 int bci = chunk->at(index)->raw_bci();
877 const char* code_name;
878 if (bci == SynchronizationEntryBCI) {
879 code_name = "sync entry";
880 } else {
881 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci);
882 code_name = Bytecodes::name(code);
883 }
884 tty->print(" - %s", code_name);
885 tty->print_cr(" @ bci %d ", bci);
886 if (Verbose) {
887 vf->print();
888 tty->cr();
889 }
890 }
891 }
892 #endif
893
894 // Register map for next frame (used for stack crawl). We capture
895 // the state of the deopt'ing frame's caller. Thus if we need to
896 // stuff a C2I adapter we can properly fill in the callee-save
897 // register locations.
898 frame caller = fr.sender(reg_map);
899 int frame_size = caller.sp() - fr.sp();
900
901 frame sender = caller;
902
903 // Since the Java thread being deoptimized will eventually adjust it's own stack,
904 // the vframeArray containing the unpacking information is allocated in the C heap.
905 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
906 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
907
908 // Compare the vframeArray to the collected vframes
909 assert(array->structural_compare(thread, chunk), "just checking");
910 Events::log("# vframes = %d", (intptr_t)chunk->length());
911
912 #ifndef PRODUCT
913 if (TraceDeoptimization) {
914 ttyLocker ttyl;
915 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
916 if (Verbose) {
917 int count = 0;
918 // this used to leak deoptimizedVFrame like it was going out of style!!!
919 for (int index = 0; index < array->frames(); index++ ) {
920 vframeArrayElement* e = array->element(index);
921 e->print(tty);
922
923 /*
924 No printing yet.
925 array->vframe_at(index)->print_activation(count++);
926 // better as...
927 array->print_activation_for(index, count++);
928 */
929 }
930 }
931 }
932 #endif // PRODUCT
933
934 return array;
935 }
936
937
938 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
939 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
940 for (int i = 0; i < monitors->length(); i++) {
941 MonitorInfo* mon_info = monitors->at(i);
942 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
943 objects_to_revoke->append(Handle(mon_info->owner()));
944 }
945 }
946 }
947
948
949 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
950 if (!UseBiasedLocking) {
951 return;
952 }
953
954 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
955
956 // Unfortunately we don't have a RegisterMap available in most of
957 // the places we want to call this routine so we need to walk the
958 // stack again to update the register map.
959 if (map == NULL || !map->update_map()) {
960 StackFrameStream sfs(thread, true);
961 bool found = false;
962 while (!found && !sfs.is_done()) {
963 frame* cur = sfs.current();
964 sfs.next();
965 found = cur->id() == fr.id();
966 }
967 assert(found, "frame to be deoptimized not found on target thread's stack");
968 map = sfs.register_map();
969 }
970
971 vframe* vf = vframe::new_vframe(&fr, map, thread);
972 compiledVFrame* cvf = compiledVFrame::cast(vf);
973 // Revoke monitors' biases in all scopes
974 while (!cvf->is_top()) {
975 collect_monitors(cvf, objects_to_revoke);
976 cvf = compiledVFrame::cast(cvf->sender());
977 }
978 collect_monitors(cvf, objects_to_revoke);
979
980 if (SafepointSynchronize::is_at_safepoint()) {
981 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
982 } else {
983 BiasedLocking::revoke(objects_to_revoke);
984 }
985 }
986
987
988 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
989 if (!UseBiasedLocking) {
990 return;
991 }
992
993 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
994 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
995 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
996 if (jt->has_last_Java_frame()) {
997 StackFrameStream sfs(jt, true);
998 while (!sfs.is_done()) {
999 frame* cur = sfs.current();
1000 if (cb->contains(cur->pc())) {
1001 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1002 compiledVFrame* cvf = compiledVFrame::cast(vf);
1003 // Revoke monitors' biases in all scopes
1004 while (!cvf->is_top()) {
1005 collect_monitors(cvf, objects_to_revoke);
1006 cvf = compiledVFrame::cast(cvf->sender());
1007 }
1008 collect_monitors(cvf, objects_to_revoke);
1009 }
1010 sfs.next();
1011 }
1012 }
1013 }
1014 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1015 }
1016
1017
1018 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1019 assert(fr.can_be_deoptimized(), "checking frame type");
1020
1021 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1022
1023 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1024
1025 // Patch the nmethod so that when execution returns to it we will
1026 // deopt the execution state and return to the interpreter.
1027 fr.deoptimize(thread);
1028 }
1029
1030 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1031 // Deoptimize only if the frame comes from compile code.
1032 // Do not deoptimize the frame which is already patched
1033 // during the execution of the loops below.
1034 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1035 return;
1036 }
1037 ResourceMark rm;
1038 DeoptimizationMarker dm;
1039 if (UseBiasedLocking) {
1040 revoke_biases_of_monitors(thread, fr, map);
1041 }
1042 deoptimize_single_frame(thread, fr);
1043
1044 }
1045
1046
1047 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1048 // Compute frame and register map based on thread and sp.
1049 RegisterMap reg_map(thread, UseBiasedLocking);
1050 frame fr = thread->last_frame();
1051 while (fr.id() != id) {
1052 fr = fr.sender(®_map);
1053 }
1054 deoptimize(thread, fr, ®_map);
1055 }
1056
1057
1058 // JVMTI PopFrame support
1059 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1060 {
1061 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1062 }
1063 JRT_END
1064
1065
1066 #ifdef COMPILER2
1067 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1068 // in case of an unresolved klass entry, load the class.
1069 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1070 klassOop tk = constant_pool->klass_at(index, CHECK);
1071 return;
1072 }
1073
1074 if (!constant_pool->tag_at(index).is_symbol()) return;
1075
1076 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1077 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1078
1079 // class name?
1080 if (symbol->byte_at(0) != '(') {
1081 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1082 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1083 return;
1084 }
1085
1086 // then it must be a signature!
1087 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1088 if (ss.is_object()) {
1089 symbolOop s = ss.as_symbol(CHECK);
1090 symbolHandle class_name (THREAD, s);
1091 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1092 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1093 }
1094 }
1095 }
1096
1097
1098 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1099 EXCEPTION_MARK;
1100 load_class_by_index(constant_pool, index, THREAD);
1101 if (HAS_PENDING_EXCEPTION) {
1102 // Exception happened during classloading. We ignore the exception here, since it
1103 // is going to be rethrown since the current activation is going to be deoptimzied and
1104 // the interpreter will re-execute the bytecode.
1105 CLEAR_PENDING_EXCEPTION;
1106 }
1107 }
1108
1109 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1110 HandleMark hm;
1111
1112 // uncommon_trap() is called at the beginning of the uncommon trap
1113 // handler. Note this fact before we start generating temporary frames
1114 // that can confuse an asynchronous stack walker. This counter is
1115 // decremented at the end of unpack_frames().
1116 thread->inc_in_deopt_handler();
1117
1118 // We need to update the map if we have biased locking.
1119 RegisterMap reg_map(thread, UseBiasedLocking);
1120 frame stub_frame = thread->last_frame();
1121 frame fr = stub_frame.sender(®_map);
1122 // Make sure the calling nmethod is not getting deoptimized and removed
1123 // before we are done with it.
1124 nmethodLocker nl(fr.pc());
1125
1126 {
1127 ResourceMark rm;
1128
1129 // Revoke biases of any monitors in the frame to ensure we can migrate them
1130 revoke_biases_of_monitors(thread, fr, ®_map);
1131
1132 DeoptReason reason = trap_request_reason(trap_request);
1133 DeoptAction action = trap_request_action(trap_request);
1134 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1135
1136 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1137 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1138 compiledVFrame* cvf = compiledVFrame::cast(vf);
1139
1140 nmethod* nm = cvf->code();
1141
1142 ScopeDesc* trap_scope = cvf->scope();
1143 methodHandle trap_method = trap_scope->method();
1144 int trap_bci = trap_scope->bci();
1145 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code();
1146
1147 // Record this event in the histogram.
1148 gather_statistics(reason, action, trap_bc);
1149
1150 // Ensure that we can record deopt. history:
1151 bool create_if_missing = ProfileTraps;
1152
1153 methodDataHandle trap_mdo
1154 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1155
1156 // Print a bunch of diagnostics, if requested.
1157 if (TraceDeoptimization || LogCompilation) {
1158 ResourceMark rm;
1159 ttyLocker ttyl;
1160 char buf[100];
1161 if (xtty != NULL) {
1162 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1163 os::current_thread_id(),
1164 format_trap_request(buf, sizeof(buf), trap_request));
1165 nm->log_identity(xtty);
1166 }
1167 symbolHandle class_name;
1168 bool unresolved = false;
1169 if (unloaded_class_index >= 0) {
1170 constantPoolHandle constants (THREAD, trap_method->constants());
1171 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1172 class_name = symbolHandle(THREAD,
1173 constants->klass_name_at(unloaded_class_index));
1174 unresolved = true;
1175 if (xtty != NULL)
1176 xtty->print(" unresolved='1'");
1177 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1178 class_name = symbolHandle(THREAD,
1179 constants->symbol_at(unloaded_class_index));
1180 }
1181 if (xtty != NULL)
1182 xtty->name(class_name);
1183 }
1184 if (xtty != NULL && trap_mdo.not_null()) {
1185 // Dump the relevant MDO state.
1186 // This is the deopt count for the current reason, any previous
1187 // reasons or recompiles seen at this point.
1188 int dcnt = trap_mdo->trap_count(reason);
1189 if (dcnt != 0)
1190 xtty->print(" count='%d'", dcnt);
1191 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1192 int dos = (pdata == NULL)? 0: pdata->trap_state();
1193 if (dos != 0) {
1194 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1195 if (trap_state_is_recompiled(dos)) {
1196 int recnt2 = trap_mdo->overflow_recompile_count();
1197 if (recnt2 != 0)
1198 xtty->print(" recompiles2='%d'", recnt2);
1199 }
1200 }
1201 }
1202 if (xtty != NULL) {
1203 xtty->stamp();
1204 xtty->end_head();
1205 }
1206 if (TraceDeoptimization) { // make noise on the tty
1207 tty->print("Uncommon trap occurred in");
1208 nm->method()->print_short_name(tty);
1209 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1210 fr.pc(),
1211 (int) os::current_thread_id(),
1212 trap_reason_name(reason),
1213 trap_action_name(action),
1214 unloaded_class_index);
1215 if (class_name.not_null()) {
1216 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1217 class_name->print_symbol_on(tty);
1218 }
1219 tty->cr();
1220 }
1221 if (xtty != NULL) {
1222 // Log the precise location of the trap.
1223 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1224 xtty->begin_elem("jvms bci='%d'", sd->bci());
1225 xtty->method(sd->method());
1226 xtty->end_elem();
1227 if (sd->is_top()) break;
1228 }
1229 xtty->tail("uncommon_trap");
1230 }
1231 }
1232 // (End diagnostic printout.)
1233
1234 // Load class if necessary
1235 if (unloaded_class_index >= 0) {
1236 constantPoolHandle constants(THREAD, trap_method->constants());
1237 load_class_by_index(constants, unloaded_class_index);
1238 }
1239
1240 // Flush the nmethod if necessary and desirable.
1241 //
1242 // We need to avoid situations where we are re-flushing the nmethod
1243 // because of a hot deoptimization site. Repeated flushes at the same
1244 // point need to be detected by the compiler and avoided. If the compiler
1245 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1246 // module must take measures to avoid an infinite cycle of recompilation
1247 // and deoptimization. There are several such measures:
1248 //
1249 // 1. If a recompilation is ordered a second time at some site X
1250 // and for the same reason R, the action is adjusted to 'reinterpret',
1251 // to give the interpreter time to exercise the method more thoroughly.
1252 // If this happens, the method's overflow_recompile_count is incremented.
1253 //
1254 // 2. If the compiler fails to reduce the deoptimization rate, then
1255 // the method's overflow_recompile_count will begin to exceed the set
1256 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1257 // is adjusted to 'make_not_compilable', and the method is abandoned
1258 // to the interpreter. This is a performance hit for hot methods,
1259 // but is better than a disastrous infinite cycle of recompilations.
1260 // (Actually, only the method containing the site X is abandoned.)
1261 //
1262 // 3. In parallel with the previous measures, if the total number of
1263 // recompilations of a method exceeds the much larger set limit
1264 // PerMethodRecompilationCutoff, the method is abandoned.
1265 // This should only happen if the method is very large and has
1266 // many "lukewarm" deoptimizations. The code which enforces this
1267 // limit is elsewhere (class nmethod, class methodOopDesc).
1268 //
1269 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1270 // to recompile at each bytecode independently of the per-BCI cutoff.
1271 //
1272 // The decision to update code is up to the compiler, and is encoded
1273 // in the Action_xxx code. If the compiler requests Action_none
1274 // no trap state is changed, no compiled code is changed, and the
1275 // computation suffers along in the interpreter.
1276 //
1277 // The other action codes specify various tactics for decompilation
1278 // and recompilation. Action_maybe_recompile is the loosest, and
1279 // allows the compiled code to stay around until enough traps are seen,
1280 // and until the compiler gets around to recompiling the trapping method.
1281 //
1282 // The other actions cause immediate removal of the present code.
1283
1284 bool update_trap_state = true;
1285 bool make_not_entrant = false;
1286 bool make_not_compilable = false;
1287 bool reset_counters = false;
1288 switch (action) {
1289 case Action_none:
1290 // Keep the old code.
1291 update_trap_state = false;
1292 break;
1293 case Action_maybe_recompile:
1294 // Do not need to invalidate the present code, but we can
1295 // initiate another
1296 // Start compiler without (necessarily) invalidating the nmethod.
1297 // The system will tolerate the old code, but new code should be
1298 // generated when possible.
1299 break;
1300 case Action_reinterpret:
1301 // Go back into the interpreter for a while, and then consider
1302 // recompiling form scratch.
1303 make_not_entrant = true;
1304 // Reset invocation counter for outer most method.
1305 // This will allow the interpreter to exercise the bytecodes
1306 // for a while before recompiling.
1307 // By contrast, Action_make_not_entrant is immediate.
1308 //
1309 // Note that the compiler will track null_check, null_assert,
1310 // range_check, and class_check events and log them as if they
1311 // had been traps taken from compiled code. This will update
1312 // the MDO trap history so that the next compilation will
1313 // properly detect hot trap sites.
1314 reset_counters = true;
1315 break;
1316 case Action_make_not_entrant:
1317 // Request immediate recompilation, and get rid of the old code.
1318 // Make them not entrant, so next time they are called they get
1319 // recompiled. Unloaded classes are loaded now so recompile before next
1320 // time they are called. Same for uninitialized. The interpreter will
1321 // link the missing class, if any.
1322 make_not_entrant = true;
1323 break;
1324 case Action_make_not_compilable:
1325 // Give up on compiling this method at all.
1326 make_not_entrant = true;
1327 make_not_compilable = true;
1328 break;
1329 default:
1330 ShouldNotReachHere();
1331 }
1332
1333 // Setting +ProfileTraps fixes the following, on all platforms:
1334 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1335 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1336 // recompile relies on a methodDataOop to record heroic opt failures.
1337
1338 // Whether the interpreter is producing MDO data or not, we also need
1339 // to use the MDO to detect hot deoptimization points and control
1340 // aggressive optimization.
1341 bool inc_recompile_count = false;
1342 ProfileData* pdata = NULL;
1343 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1344 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1345 uint this_trap_count = 0;
1346 bool maybe_prior_trap = false;
1347 bool maybe_prior_recompile = false;
1348 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1349 //outputs:
1350 this_trap_count,
1351 maybe_prior_trap,
1352 maybe_prior_recompile);
1353 // Because the interpreter also counts null, div0, range, and class
1354 // checks, these traps from compiled code are double-counted.
1355 // This is harmless; it just means that the PerXTrapLimit values
1356 // are in effect a little smaller than they look.
1357
1358 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1359 if (per_bc_reason != Reason_none) {
1360 // Now take action based on the partially known per-BCI history.
1361 if (maybe_prior_trap
1362 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1363 // If there are too many traps at this BCI, force a recompile.
1364 // This will allow the compiler to see the limit overflow, and
1365 // take corrective action, if possible. The compiler generally
1366 // does not use the exact PerBytecodeTrapLimit value, but instead
1367 // changes its tactics if it sees any traps at all. This provides
1368 // a little hysteresis, delaying a recompile until a trap happens
1369 // several times.
1370 //
1371 // Actually, since there is only one bit of counter per BCI,
1372 // the possible per-BCI counts are {0,1,(per-method count)}.
1373 // This produces accurate results if in fact there is only
1374 // one hot trap site, but begins to get fuzzy if there are
1375 // many sites. For example, if there are ten sites each
1376 // trapping two or more times, they each get the blame for
1377 // all of their traps.
1378 make_not_entrant = true;
1379 }
1380
1381 // Detect repeated recompilation at the same BCI, and enforce a limit.
1382 if (make_not_entrant && maybe_prior_recompile) {
1383 // More than one recompile at this point.
1384 inc_recompile_count = maybe_prior_trap;
1385 }
1386 } else {
1387 // For reasons which are not recorded per-bytecode, we simply
1388 // force recompiles unconditionally.
1389 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1390 make_not_entrant = true;
1391 }
1392
1393 // Go back to the compiler if there are too many traps in this method.
1394 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1395 // If there are too many traps in this method, force a recompile.
1396 // This will allow the compiler to see the limit overflow, and
1397 // take corrective action, if possible.
1398 // (This condition is an unlikely backstop only, because the
1399 // PerBytecodeTrapLimit is more likely to take effect first,
1400 // if it is applicable.)
1401 make_not_entrant = true;
1402 }
1403
1404 // Here's more hysteresis: If there has been a recompile at
1405 // this trap point already, run the method in the interpreter
1406 // for a while to exercise it more thoroughly.
1407 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1408 reset_counters = true;
1409 }
1410
1411 }
1412
1413 // Take requested actions on the method:
1414
1415 // Recompile
1416 if (make_not_entrant) {
1417 if (!nm->make_not_entrant()) {
1418 return; // the call did not change nmethod's state
1419 }
1420
1421 if (pdata != NULL) {
1422 // Record the recompilation event, if any.
1423 int tstate0 = pdata->trap_state();
1424 int tstate1 = trap_state_set_recompiled(tstate0, true);
1425 if (tstate1 != tstate0)
1426 pdata->set_trap_state(tstate1);
1427 }
1428 }
1429
1430 if (inc_recompile_count) {
1431 trap_mdo->inc_overflow_recompile_count();
1432 if ((uint)trap_mdo->overflow_recompile_count() >
1433 (uint)PerBytecodeRecompilationCutoff) {
1434 // Give up on the method containing the bad BCI.
1435 if (trap_method() == nm->method()) {
1436 make_not_compilable = true;
1437 } else {
1438 trap_method->set_not_compilable();
1439 // But give grace to the enclosing nm->method().
1440 }
1441 }
1442 }
1443
1444 // Reset invocation counters
1445 if (reset_counters) {
1446 if (nm->is_osr_method())
1447 reset_invocation_counter(trap_scope, CompileThreshold);
1448 else
1449 reset_invocation_counter(trap_scope);
1450 }
1451
1452 // Give up compiling
1453 if (make_not_compilable && !nm->method()->is_not_compilable()) {
1454 assert(make_not_entrant, "consistent");
1455 nm->method()->set_not_compilable();
1456 }
1457
1458 } // Free marked resources
1459
1460 }
1461 JRT_END
1462
1463 methodDataOop
1464 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1465 bool create_if_missing) {
1466 Thread* THREAD = thread;
1467 methodDataOop mdo = m()->method_data();
1468 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1469 // Build an MDO. Ignore errors like OutOfMemory;
1470 // that simply means we won't have an MDO to update.
1471 methodOopDesc::build_interpreter_method_data(m, THREAD);
1472 if (HAS_PENDING_EXCEPTION) {
1473 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1474 CLEAR_PENDING_EXCEPTION;
1475 }
1476 mdo = m()->method_data();
1477 }
1478 return mdo;
1479 }
1480
1481 ProfileData*
1482 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1483 int trap_bci,
1484 Deoptimization::DeoptReason reason,
1485 //outputs:
1486 uint& ret_this_trap_count,
1487 bool& ret_maybe_prior_trap,
1488 bool& ret_maybe_prior_recompile) {
1489 uint prior_trap_count = trap_mdo->trap_count(reason);
1490 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1491
1492 // If the runtime cannot find a place to store trap history,
1493 // it is estimated based on the general condition of the method.
1494 // If the method has ever been recompiled, or has ever incurred
1495 // a trap with the present reason , then this BCI is assumed
1496 // (pessimistically) to be the culprit.
1497 bool maybe_prior_trap = (prior_trap_count != 0);
1498 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1499 ProfileData* pdata = NULL;
1500
1501
1502 // For reasons which are recorded per bytecode, we check per-BCI data.
1503 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1504 if (per_bc_reason != Reason_none) {
1505 // Find the profile data for this BCI. If there isn't one,
1506 // try to allocate one from the MDO's set of spares.
1507 // This will let us detect a repeated trap at this point.
1508 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1509
1510 if (pdata != NULL) {
1511 // Query the trap state of this profile datum.
1512 int tstate0 = pdata->trap_state();
1513 if (!trap_state_has_reason(tstate0, per_bc_reason))
1514 maybe_prior_trap = false;
1515 if (!trap_state_is_recompiled(tstate0))
1516 maybe_prior_recompile = false;
1517
1518 // Update the trap state of this profile datum.
1519 int tstate1 = tstate0;
1520 // Record the reason.
1521 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1522 // Store the updated state on the MDO, for next time.
1523 if (tstate1 != tstate0)
1524 pdata->set_trap_state(tstate1);
1525 } else {
1526 if (LogCompilation && xtty != NULL) {
1527 ttyLocker ttyl;
1528 // Missing MDP? Leave a small complaint in the log.
1529 xtty->elem("missing_mdp bci='%d'", trap_bci);
1530 }
1531 }
1532 }
1533
1534 // Return results:
1535 ret_this_trap_count = this_trap_count;
1536 ret_maybe_prior_trap = maybe_prior_trap;
1537 ret_maybe_prior_recompile = maybe_prior_recompile;
1538 return pdata;
1539 }
1540
1541 void
1542 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1543 ResourceMark rm;
1544 // Ignored outputs:
1545 uint ignore_this_trap_count;
1546 bool ignore_maybe_prior_trap;
1547 bool ignore_maybe_prior_recompile;
1548 query_update_method_data(trap_mdo, trap_bci,
1549 (DeoptReason)reason,
1550 ignore_this_trap_count,
1551 ignore_maybe_prior_trap,
1552 ignore_maybe_prior_recompile);
1553 }
1554
1555 void Deoptimization::reset_invocation_counter(ScopeDesc* trap_scope, jint top_count) {
1556 ScopeDesc* sd = trap_scope;
1557 for (; !sd->is_top(); sd = sd->sender()) {
1558 // Reset ICs of inlined methods, since they can trigger compilations also.
1559 sd->method()->invocation_counter()->reset();
1560 }
1561 InvocationCounter* c = sd->method()->invocation_counter();
1562 if (top_count != _no_count) {
1563 // It was an OSR method, so bump the count higher.
1564 c->set(c->state(), top_count);
1565 } else {
1566 c->reset();
1567 }
1568 sd->method()->backedge_counter()->reset();
1569 }
1570
1571 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1572
1573 // Still in Java no safepoints
1574 {
1575 // This enters VM and may safepoint
1576 uncommon_trap_inner(thread, trap_request);
1577 }
1578 return fetch_unroll_info_helper(thread);
1579 }
1580
1581 // Local derived constants.
1582 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1583 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1584 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1585
1586 //---------------------------trap_state_reason---------------------------------
1587 Deoptimization::DeoptReason
1588 Deoptimization::trap_state_reason(int trap_state) {
1589 // This assert provides the link between the width of DataLayout::trap_bits
1590 // and the encoding of "recorded" reasons. It ensures there are enough
1591 // bits to store all needed reasons in the per-BCI MDO profile.
1592 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1593 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1594 trap_state -= recompile_bit;
1595 if (trap_state == DS_REASON_MASK) {
1596 return Reason_many;
1597 } else {
1598 assert((int)Reason_none == 0, "state=0 => Reason_none");
1599 return (DeoptReason)trap_state;
1600 }
1601 }
1602 //-------------------------trap_state_has_reason-------------------------------
1603 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1604 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1605 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1606 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1607 trap_state -= recompile_bit;
1608 if (trap_state == DS_REASON_MASK) {
1609 return -1; // true, unspecifically (bottom of state lattice)
1610 } else if (trap_state == reason) {
1611 return 1; // true, definitely
1612 } else if (trap_state == 0) {
1613 return 0; // false, definitely (top of state lattice)
1614 } else {
1615 return 0; // false, definitely
1616 }
1617 }
1618 //-------------------------trap_state_add_reason-------------------------------
1619 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1620 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1621 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1622 trap_state -= recompile_bit;
1623 if (trap_state == DS_REASON_MASK) {
1624 return trap_state + recompile_bit; // already at state lattice bottom
1625 } else if (trap_state == reason) {
1626 return trap_state + recompile_bit; // the condition is already true
1627 } else if (trap_state == 0) {
1628 return reason + recompile_bit; // no condition has yet been true
1629 } else {
1630 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1631 }
1632 }
1633 //-----------------------trap_state_is_recompiled------------------------------
1634 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1635 return (trap_state & DS_RECOMPILE_BIT) != 0;
1636 }
1637 //-----------------------trap_state_set_recompiled-----------------------------
1638 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1639 if (z) return trap_state | DS_RECOMPILE_BIT;
1640 else return trap_state & ~DS_RECOMPILE_BIT;
1641 }
1642 //---------------------------format_trap_state---------------------------------
1643 // This is used for debugging and diagnostics, including hotspot.log output.
1644 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1645 int trap_state) {
1646 DeoptReason reason = trap_state_reason(trap_state);
1647 bool recomp_flag = trap_state_is_recompiled(trap_state);
1648 // Re-encode the state from its decoded components.
1649 int decoded_state = 0;
1650 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1651 decoded_state = trap_state_add_reason(decoded_state, reason);
1652 if (recomp_flag)
1653 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1654 // If the state re-encodes properly, format it symbolically.
1655 // Because this routine is used for debugging and diagnostics,
1656 // be robust even if the state is a strange value.
1657 size_t len;
1658 if (decoded_state != trap_state) {
1659 // Random buggy state that doesn't decode??
1660 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1661 } else {
1662 len = jio_snprintf(buf, buflen, "%s%s",
1663 trap_reason_name(reason),
1664 recomp_flag ? " recompiled" : "");
1665 }
1666 if (len >= buflen)
1667 buf[buflen-1] = '\0';
1668 return buf;
1669 }
1670
1671
1672 //--------------------------------statics--------------------------------------
1673 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1674 = Deoptimization::Action_reinterpret;
1675 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1676 // Note: Keep this in sync. with enum DeoptReason.
1677 "none",
1678 "null_check",
1679 "null_assert",
1680 "range_check",
1681 "class_check",
1682 "array_check",
1683 "intrinsic",
1684 "bimorphic",
1685 "unloaded",
1686 "uninitialized",
1687 "unreached",
1688 "unhandled",
1689 "constraint",
1690 "div0_check",
1691 "age",
1692 "predicate"
1693 };
1694 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1695 // Note: Keep this in sync. with enum DeoptAction.
1696 "none",
1697 "maybe_recompile",
1698 "reinterpret",
1699 "make_not_entrant",
1700 "make_not_compilable"
1701 };
1702
1703 const char* Deoptimization::trap_reason_name(int reason) {
1704 if (reason == Reason_many) return "many";
1705 if ((uint)reason < Reason_LIMIT)
1706 return _trap_reason_name[reason];
1707 static char buf[20];
1708 sprintf(buf, "reason%d", reason);
1709 return buf;
1710 }
1711 const char* Deoptimization::trap_action_name(int action) {
1712 if ((uint)action < Action_LIMIT)
1713 return _trap_action_name[action];
1714 static char buf[20];
1715 sprintf(buf, "action%d", action);
1716 return buf;
1717 }
1718
1719 // This is used for debugging and diagnostics, including hotspot.log output.
1720 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1721 int trap_request) {
1722 jint unloaded_class_index = trap_request_index(trap_request);
1723 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1724 const char* action = trap_action_name(trap_request_action(trap_request));
1725 size_t len;
1726 if (unloaded_class_index < 0) {
1727 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1728 reason, action);
1729 } else {
1730 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1731 reason, action, unloaded_class_index);
1732 }
1733 if (len >= buflen)
1734 buf[buflen-1] = '\0';
1735 return buf;
1736 }
1737
1738 juint Deoptimization::_deoptimization_hist
1739 [Deoptimization::Reason_LIMIT]
1740 [1 + Deoptimization::Action_LIMIT]
1741 [Deoptimization::BC_CASE_LIMIT]
1742 = {0};
1743
1744 enum {
1745 LSB_BITS = 8,
1746 LSB_MASK = right_n_bits(LSB_BITS)
1747 };
1748
1749 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1750 Bytecodes::Code bc) {
1751 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1752 assert(action >= 0 && action < Action_LIMIT, "oob");
1753 _deoptimization_hist[Reason_none][0][0] += 1; // total
1754 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1755 juint* cases = _deoptimization_hist[reason][1+action];
1756 juint* bc_counter_addr = NULL;
1757 juint bc_counter = 0;
1758 // Look for an unused counter, or an exact match to this BC.
1759 if (bc != Bytecodes::_illegal) {
1760 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1761 juint* counter_addr = &cases[bc_case];
1762 juint counter = *counter_addr;
1763 if ((counter == 0 && bc_counter_addr == NULL)
1764 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1765 // this counter is either free or is already devoted to this BC
1766 bc_counter_addr = counter_addr;
1767 bc_counter = counter | bc;
1768 }
1769 }
1770 }
1771 if (bc_counter_addr == NULL) {
1772 // Overflow, or no given bytecode.
1773 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1774 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1775 }
1776 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1777 }
1778
1779 jint Deoptimization::total_deoptimization_count() {
1780 return _deoptimization_hist[Reason_none][0][0];
1781 }
1782
1783 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1784 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1785 return _deoptimization_hist[reason][0][0];
1786 }
1787
1788 void Deoptimization::print_statistics() {
1789 juint total = total_deoptimization_count();
1790 juint account = total;
1791 if (total != 0) {
1792 ttyLocker ttyl;
1793 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1794 tty->print_cr("Deoptimization traps recorded:");
1795 #define PRINT_STAT_LINE(name, r) \
1796 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1797 PRINT_STAT_LINE("total", total);
1798 // For each non-zero entry in the histogram, print the reason,
1799 // the action, and (if specifically known) the type of bytecode.
1800 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1801 for (int action = 0; action < Action_LIMIT; action++) {
1802 juint* cases = _deoptimization_hist[reason][1+action];
1803 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1804 juint counter = cases[bc_case];
1805 if (counter != 0) {
1806 char name[1*K];
1807 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1808 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1809 bc = Bytecodes::_illegal;
1810 sprintf(name, "%s/%s/%s",
1811 trap_reason_name(reason),
1812 trap_action_name(action),
1813 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1814 juint r = counter >> LSB_BITS;
1815 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1816 account -= r;
1817 }
1818 }
1819 }
1820 }
1821 if (account != 0) {
1822 PRINT_STAT_LINE("unaccounted", account);
1823 }
1824 #undef PRINT_STAT_LINE
1825 if (xtty != NULL) xtty->tail("statistics");
1826 }
1827 }
1828 #else // COMPILER2
1829
1830
1831 // Stubs for C1 only system.
1832 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1833 return false;
1834 }
1835
1836 const char* Deoptimization::trap_reason_name(int reason) {
1837 return "unknown";
1838 }
1839
1840 void Deoptimization::print_statistics() {
1841 // no output
1842 }
1843
1844 void
1845 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1846 // no udpate
1847 }
1848
1849 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1850 return 0;
1851 }
1852
1853 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1854 Bytecodes::Code bc) {
1855 // no update
1856 }
1857
1858 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1859 int trap_state) {
1860 jio_snprintf(buf, buflen, "#%d", trap_state);
1861 return buf;
1862 }
1863
1864 #endif // COMPILER2