1 /*
2 * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "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 // Set the deoptee nmethod
128 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
129 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
130
131 // Create a growable array of VFrames where each VFrame represents an inlined
132 // Java frame. This storage is allocated with the usual system arena.
133 assert(deoptee.is_compiled_frame(), "Wrong frame type");
134 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
135 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
136 while (!vf->is_top()) {
137 assert(vf->is_compiled_frame(), "Wrong frame type");
138 chunk->push(compiledVFrame::cast(vf));
139 vf = vf->sender();
140 }
141 assert(vf->is_compiled_frame(), "Wrong frame type");
142 chunk->push(compiledVFrame::cast(vf));
143
144 #ifdef COMPILER2
145 // Reallocate the non-escaping objects and restore their fields. Then
146 // relock objects if synchronization on them was eliminated.
147 if (DoEscapeAnalysis) {
148 if (EliminateAllocations) {
149 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
150 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
151
152 // The flag return_oop() indicates call sites which return oop
153 // in compiled code. Such sites include java method calls,
154 // runtime calls (for example, used to allocate new objects/arrays
155 // on slow code path) and any other calls generated in compiled code.
156 // It is not guaranteed that we can get such information here only
157 // by analyzing bytecode in deoptimized frames. This is why this flag
158 // is set during method compilation (see Compile::Process_OopMap_Node()).
159 bool save_oop_result = chunk->at(0)->scope()->return_oop();
160 Handle return_value;
161 if (save_oop_result) {
162 // Reallocation may trigger GC. If deoptimization happened on return from
163 // call which returns oop we need to save it since it is not in oopmap.
164 oop result = deoptee.saved_oop_result(&map);
165 assert(result == NULL || result->is_oop(), "must be oop");
166 return_value = Handle(thread, result);
167 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
168 if (TraceDeoptimization) {
169 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
170 }
171 }
172 bool reallocated = false;
173 if (objects != NULL) {
174 JRT_BLOCK
175 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
176 JRT_END
177 }
178 if (reallocated) {
179 reassign_fields(&deoptee, &map, objects);
180 #ifndef PRODUCT
181 if (TraceDeoptimization) {
182 ttyLocker ttyl;
183 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
184 print_objects(objects);
185 }
186 #endif
187 }
188 if (save_oop_result) {
189 // Restore result.
190 deoptee.set_saved_oop_result(&map, return_value());
191 }
192 }
193 if (EliminateLocks) {
194 #ifndef PRODUCT
195 bool first = true;
196 #endif
197 for (int i = 0; i < chunk->length(); i++) {
198 compiledVFrame* cvf = chunk->at(i);
199 assert (cvf->scope() != NULL,"expect only compiled java frames");
200 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
201 if (monitors->is_nonempty()) {
202 relock_objects(monitors, thread);
203 #ifndef PRODUCT
204 if (TraceDeoptimization) {
205 ttyLocker ttyl;
206 for (int j = 0; j < monitors->length(); j++) {
207 MonitorInfo* mi = monitors->at(j);
208 if (mi->eliminated()) {
209 if (first) {
210 first = false;
211 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
212 }
213 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
214 }
215 }
216 }
217 #endif
218 }
219 }
220 }
221 }
222 #endif // COMPILER2
223 // Ensure that no safepoint is taken after pointers have been stored
224 // in fields of rematerialized objects. If a safepoint occurs from here on
225 // out the java state residing in the vframeArray will be missed.
226 No_Safepoint_Verifier no_safepoint;
227
228 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
229
230 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
231 thread->set_vframe_array_head(array);
232
233 // Now that the vframeArray has been created if we have any deferred local writes
234 // added by jvmti then we can free up that structure as the data is now in the
235 // vframeArray
236
237 if (thread->deferred_locals() != NULL) {
238 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
239 int i = 0;
240 do {
241 // Because of inlining we could have multiple vframes for a single frame
242 // and several of the vframes could have deferred writes. Find them all.
243 if (list->at(i)->id() == array->original().id()) {
244 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
245 list->remove_at(i);
246 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
247 delete dlv;
248 } else {
249 i++;
250 }
251 } while ( i < list->length() );
252 if (list->length() == 0) {
253 thread->set_deferred_locals(NULL);
254 // free the list and elements back to C heap.
255 delete list;
256 }
257
258 }
259
260 #ifndef SHARK
261 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
262 CodeBlob* cb = stub_frame.cb();
263 // Verify we have the right vframeArray
264 assert(cb->frame_size() >= 0, "Unexpected frame size");
265 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
266
267 // If the deopt call site is a MethodHandle invoke call site we have
268 // to adjust the unpack_sp.
269 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
270 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
271 unpack_sp = deoptee.unextended_sp();
272
273 #ifdef ASSERT
274 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
275 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
276 #endif
277 #else
278 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
279 #endif // !SHARK
280
281 // This is a guarantee instead of an assert because if vframe doesn't match
282 // we will unpack the wrong deoptimized frame and wind up in strange places
283 // where it will be very difficult to figure out what went wrong. Better
284 // to die an early death here than some very obscure death later when the
285 // trail is cold.
286 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
287 // in that it will fail to detect a problem when there is one. This needs
288 // more work in tiger timeframe.
289 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
290
291 int number_of_frames = array->frames();
292
293 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
294 // virtual activation, which is the reverse of the elements in the vframes array.
295 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
296 // +1 because we always have an interpreter return address for the final slot.
297 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
298 int callee_parameters = 0;
299 int callee_locals = 0;
300 int popframe_extra_args = 0;
301 // Create an interpreter return address for the stub to use as its return
302 // address so the skeletal frames are perfectly walkable
303 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
304
305 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
306 // activation be put back on the expression stack of the caller for reexecution
307 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
308 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
309 }
310
311 //
312 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
313 // frame_sizes/frame_pcs[1] next oldest frame (int)
314 // frame_sizes/frame_pcs[n] youngest frame (int)
315 //
316 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
317 // owns the space for the return address to it's caller). Confusing ain't it.
318 //
319 // The vframe array can address vframes with indices running from
320 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
321 // When we create the skeletal frames we need the oldest frame to be in the zero slot
322 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
323 // so things look a little strange in this loop.
324 //
325 for (int index = 0; index < array->frames(); index++ ) {
326 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
327 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
328 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
329 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
330 callee_locals,
331 index == 0,
332 popframe_extra_args);
333 // This pc doesn't have to be perfect just good enough to identify the frame
334 // as interpreted so the skeleton frame will be walkable
335 // The correct pc will be set when the skeleton frame is completely filled out
336 // The final pc we store in the loop is wrong and will be overwritten below
337 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
338
339 callee_parameters = array->element(index)->method()->size_of_parameters();
340 callee_locals = array->element(index)->method()->max_locals();
341 popframe_extra_args = 0;
342 }
343
344 // Compute whether the root vframe returns a float or double value.
345 BasicType return_type;
346 {
347 HandleMark hm;
348 methodHandle method(thread, array->element(0)->method());
349 Bytecode_invoke* invoke = Bytecode_invoke_at_check(method, array->element(0)->bci());
350 return_type = (invoke != NULL) ? invoke->result_type(thread) : T_ILLEGAL;
351 }
352
353 // Compute information for handling adapters and adjusting the frame size of the caller.
354 int caller_adjustment = 0;
355
356 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
357 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
358 // than simply use array->sender.pc(). This requires us to walk the current set of frames
359 //
360 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
361 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
362
363 // Compute the amount the oldest interpreter frame will have to adjust
364 // its caller's stack by. If the caller is a compiled frame then
365 // we pretend that the callee has no parameters so that the
366 // extension counts for the full amount of locals and not just
367 // locals-parms. This is because without a c2i adapter the parm
368 // area as created by the compiled frame will not be usable by
369 // the interpreter. (Depending on the calling convention there
370 // may not even be enough space).
371
372 // QQQ I'd rather see this pushed down into last_frame_adjust
373 // and have it take the sender (aka caller).
374
375 if (deopt_sender.is_compiled_frame()) {
376 caller_adjustment = last_frame_adjust(0, callee_locals);
377 } else if (callee_locals > callee_parameters) {
378 // The caller frame may need extending to accommodate
379 // non-parameter locals of the first unpacked interpreted frame.
380 // Compute that adjustment.
381 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
382 }
383
384
385 // If the sender is deoptimized the we must retrieve the address of the handler
386 // since the frame will "magically" show the original pc before the deopt
387 // and we'd undo the deopt.
388
389 frame_pcs[0] = deopt_sender.raw_pc();
390
391 #ifndef SHARK
392 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
393 #endif // SHARK
394
395 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
396 caller_adjustment * BytesPerWord,
397 number_of_frames,
398 frame_sizes,
399 frame_pcs,
400 return_type);
401 #if defined(IA32) || defined(AMD64)
402 // We need a way to pass fp to the unpacking code so the skeletal frames
403 // come out correct. This is only needed for x86 because of c2 using ebp
404 // as an allocatable register. So this update is useless (and harmless)
405 // on the other platforms. It would be nice to do this in a different
406 // way but even the old style deoptimization had a problem with deriving
407 // this value. NEEDS_CLEANUP
408 // Note: now that c1 is using c2's deopt blob we must do this on all
409 // x86 based platforms
410 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
411 *fp_addr = array->sender().fp(); // was adapter_caller
412 #endif /* IA32 || AMD64 */
413
414 if (array->frames() > 1) {
415 if (VerifyStack && TraceDeoptimization) {
416 tty->print_cr("Deoptimizing method containing inlining");
417 }
418 }
419
420 array->set_unroll_block(info);
421 return info;
422 }
423
424 // Called to cleanup deoptimization data structures in normal case
425 // after unpacking to stack and when stack overflow error occurs
426 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
427 vframeArray *array) {
428
429 // Get array if coming from exception
430 if (array == NULL) {
431 array = thread->vframe_array_head();
432 }
433 thread->set_vframe_array_head(NULL);
434
435 // Free the previous UnrollBlock
436 vframeArray* old_array = thread->vframe_array_last();
437 thread->set_vframe_array_last(array);
438
439 if (old_array != NULL) {
440 UnrollBlock* old_info = old_array->unroll_block();
441 old_array->set_unroll_block(NULL);
442 delete old_info;
443 delete old_array;
444 }
445
446 // Deallocate any resource creating in this routine and any ResourceObjs allocated
447 // inside the vframeArray (StackValueCollections)
448
449 delete thread->deopt_mark();
450 thread->set_deopt_mark(NULL);
451 thread->set_deopt_nmethod(NULL);
452
453
454 if (JvmtiExport::can_pop_frame()) {
455 #ifndef CC_INTERP
456 // Regardless of whether we entered this routine with the pending
457 // popframe condition bit set, we should always clear it now
458 thread->clear_popframe_condition();
459 #else
460 // C++ interpeter will clear has_pending_popframe when it enters
461 // with method_resume. For deopt_resume2 we clear it now.
462 if (thread->popframe_forcing_deopt_reexecution())
463 thread->clear_popframe_condition();
464 #endif /* CC_INTERP */
465 }
466
467 // unpack_frames() is called at the end of the deoptimization handler
468 // and (in C2) at the end of the uncommon trap handler. Note this fact
469 // so that an asynchronous stack walker can work again. This counter is
470 // incremented at the beginning of fetch_unroll_info() and (in C2) at
471 // the beginning of uncommon_trap().
472 thread->dec_in_deopt_handler();
473 }
474
475
476 // Return BasicType of value being returned
477 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
478
479 // We are already active int he special DeoptResourceMark any ResourceObj's we
480 // allocate will be freed at the end of the routine.
481
482 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
483 // but makes the entry a little slower. There is however a little dance we have to
484 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
485 ResetNoHandleMark rnhm; // No-op in release/product versions
486 HandleMark hm;
487
488 frame stub_frame = thread->last_frame();
489
490 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
491 // must point to the vframeArray for the unpack frame.
492 vframeArray* array = thread->vframe_array_head();
493
494 #ifndef PRODUCT
495 if (TraceDeoptimization) {
496 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
497 }
498 #endif
499
500 UnrollBlock* info = array->unroll_block();
501
502 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
503 array->unpack_to_stack(stub_frame, exec_mode);
504
505 BasicType bt = info->return_type();
506
507 // If we have an exception pending, claim that the return type is an oop
508 // so the deopt_blob does not overwrite the exception_oop.
509
510 if (exec_mode == Unpack_exception)
511 bt = T_OBJECT;
512
513 // Cleanup thread deopt data
514 cleanup_deopt_info(thread, array);
515
516 #ifndef PRODUCT
517 if (VerifyStack) {
518 ResourceMark res_mark;
519
520 // Verify that the just-unpacked frames match the interpreter's
521 // notions of expression stack and locals
522 vframeArray* cur_array = thread->vframe_array_last();
523 RegisterMap rm(thread, false);
524 rm.set_include_argument_oops(false);
525 bool is_top_frame = true;
526 int callee_size_of_parameters = 0;
527 int callee_max_locals = 0;
528 for (int i = 0; i < cur_array->frames(); i++) {
529 vframeArrayElement* el = cur_array->element(i);
530 frame* iframe = el->iframe();
531 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
532
533 // Get the oop map for this bci
534 InterpreterOopMap mask;
535 int cur_invoke_parameter_size = 0;
536 bool try_next_mask = false;
537 int next_mask_expression_stack_size = -1;
538 int top_frame_expression_stack_adjustment = 0;
539 methodHandle mh(thread, iframe->interpreter_frame_method());
540 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
541 BytecodeStream str(mh);
542 str.set_start(iframe->interpreter_frame_bci());
543 int max_bci = mh->code_size();
544 // Get to the next bytecode if possible
545 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
546 // Check to see if we can grab the number of outgoing arguments
547 // at an uncommon trap for an invoke (where the compiler
548 // generates debug info before the invoke has executed)
549 Bytecodes::Code cur_code = str.next();
550 if (cur_code == Bytecodes::_invokevirtual ||
551 cur_code == Bytecodes::_invokespecial ||
552 cur_code == Bytecodes::_invokestatic ||
553 cur_code == Bytecodes::_invokeinterface) {
554 Bytecode_invoke* invoke = Bytecode_invoke_at(mh, iframe->interpreter_frame_bci());
555 symbolHandle signature(thread, invoke->signature());
556 ArgumentSizeComputer asc(signature);
557 cur_invoke_parameter_size = asc.size();
558 if (cur_code != Bytecodes::_invokestatic) {
559 // Add in receiver
560 ++cur_invoke_parameter_size;
561 }
562 }
563 if (str.bci() < max_bci) {
564 Bytecodes::Code bc = str.next();
565 if (bc >= 0) {
566 // The interpreter oop map generator reports results before
567 // the current bytecode has executed except in the case of
568 // calls. It seems to be hard to tell whether the compiler
569 // has emitted debug information matching the "state before"
570 // a given bytecode or the state after, so we try both
571 switch (cur_code) {
572 case Bytecodes::_invokevirtual:
573 case Bytecodes::_invokespecial:
574 case Bytecodes::_invokestatic:
575 case Bytecodes::_invokeinterface:
576 case Bytecodes::_athrow:
577 break;
578 default: {
579 InterpreterOopMap next_mask;
580 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
581 next_mask_expression_stack_size = next_mask.expression_stack_size();
582 // Need to subtract off the size of the result type of
583 // the bytecode because this is not described in the
584 // debug info but returned to the interpreter in the TOS
585 // caching register
586 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
587 if (bytecode_result_type != T_ILLEGAL) {
588 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
589 }
590 assert(top_frame_expression_stack_adjustment >= 0, "");
591 try_next_mask = true;
592 break;
593 }
594 }
595 }
596 }
597
598 // Verify stack depth and oops in frame
599 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
600 if (!(
601 /* SPARC */
602 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
603 /* x86 */
604 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
605 (try_next_mask &&
606 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
607 top_frame_expression_stack_adjustment))) ||
608 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
609 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
610 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
611 )) {
612 ttyLocker ttyl;
613
614 // Print out some information that will help us debug the problem
615 tty->print_cr("Wrong number of expression stack elements during deoptimization");
616 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
617 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
618 iframe->interpreter_frame_expression_stack_size());
619 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
620 tty->print_cr(" try_next_mask = %d", try_next_mask);
621 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
622 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
623 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
624 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
625 tty->print_cr(" exec_mode = %d", exec_mode);
626 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
627 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
628 tty->print_cr(" Interpreted frames:");
629 for (int k = 0; k < cur_array->frames(); k++) {
630 vframeArrayElement* el = cur_array->element(k);
631 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
632 }
633 cur_array->print_on_2(tty);
634 guarantee(false, "wrong number of expression stack elements during deopt");
635 }
636 VerifyOopClosure verify;
637 iframe->oops_interpreted_do(&verify, &rm, false);
638 callee_size_of_parameters = mh->size_of_parameters();
639 callee_max_locals = mh->max_locals();
640 is_top_frame = false;
641 }
642 }
643 #endif /* !PRODUCT */
644
645
646 return bt;
647 JRT_END
648
649
650 int Deoptimization::deoptimize_dependents() {
651 Threads::deoptimized_wrt_marked_nmethods();
652 return 0;
653 }
654
655
656 #ifdef COMPILER2
657 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
658 Handle pending_exception(thread->pending_exception());
659 const char* exception_file = thread->exception_file();
660 int exception_line = thread->exception_line();
661 thread->clear_pending_exception();
662
663 for (int i = 0; i < objects->length(); i++) {
664 assert(objects->at(i)->is_object(), "invalid debug information");
665 ObjectValue* sv = (ObjectValue*) objects->at(i);
666
667 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
668 oop obj = NULL;
669
670 if (k->oop_is_instance()) {
671 instanceKlass* ik = instanceKlass::cast(k());
672 obj = ik->allocate_instance(CHECK_(false));
673 } else if (k->oop_is_typeArray()) {
674 typeArrayKlass* ak = typeArrayKlass::cast(k());
675 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
676 int len = sv->field_size() / type2size[ak->element_type()];
677 obj = ak->allocate(len, CHECK_(false));
678 } else if (k->oop_is_objArray()) {
679 objArrayKlass* ak = objArrayKlass::cast(k());
680 obj = ak->allocate(sv->field_size(), CHECK_(false));
681 }
682
683 assert(obj != NULL, "allocation failed");
684 assert(sv->value().is_null(), "redundant reallocation");
685 sv->set_value(obj);
686 }
687
688 if (pending_exception.not_null()) {
689 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
690 }
691
692 return true;
693 }
694
695 // This assumes that the fields are stored in ObjectValue in the same order
696 // they are yielded by do_nonstatic_fields.
697 class FieldReassigner: public FieldClosure {
698 frame* _fr;
699 RegisterMap* _reg_map;
700 ObjectValue* _sv;
701 instanceKlass* _ik;
702 oop _obj;
703
704 int _i;
705 public:
706 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
707 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
708
709 int i() const { return _i; }
710
711
712 void do_field(fieldDescriptor* fd) {
713 intptr_t val;
714 StackValue* value =
715 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
716 int offset = fd->offset();
717 switch (fd->field_type()) {
718 case T_OBJECT: case T_ARRAY:
719 assert(value->type() == T_OBJECT, "Agreement.");
720 _obj->obj_field_put(offset, value->get_obj()());
721 break;
722
723 case T_LONG: case T_DOUBLE: {
724 assert(value->type() == T_INT, "Agreement.");
725 StackValue* low =
726 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
727 #ifdef _LP64
728 jlong res = (jlong)low->get_int();
729 #else
730 #ifdef SPARC
731 // For SPARC we have to swap high and low words.
732 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
733 #else
734 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
735 #endif //SPARC
736 #endif
737 _obj->long_field_put(offset, res);
738 break;
739 }
740 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
741 case T_INT: case T_FLOAT: // 4 bytes.
742 assert(value->type() == T_INT, "Agreement.");
743 val = value->get_int();
744 _obj->int_field_put(offset, (jint)*((jint*)&val));
745 break;
746
747 case T_SHORT: case T_CHAR: // 2 bytes
748 assert(value->type() == T_INT, "Agreement.");
749 val = value->get_int();
750 _obj->short_field_put(offset, (jshort)*((jint*)&val));
751 break;
752
753 case T_BOOLEAN: case T_BYTE: // 1 byte
754 assert(value->type() == T_INT, "Agreement.");
755 val = value->get_int();
756 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
757 break;
758
759 default:
760 ShouldNotReachHere();
761 }
762 _i++;
763 }
764 };
765
766 // restore elements of an eliminated type array
767 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
768 int index = 0;
769 intptr_t val;
770
771 for (int i = 0; i < sv->field_size(); i++) {
772 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
773 switch(type) {
774 case T_LONG: case T_DOUBLE: {
775 assert(value->type() == T_INT, "Agreement.");
776 StackValue* low =
777 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
778 #ifdef _LP64
779 jlong res = (jlong)low->get_int();
780 #else
781 #ifdef SPARC
782 // For SPARC we have to swap high and low words.
783 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
784 #else
785 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
786 #endif //SPARC
787 #endif
788 obj->long_at_put(index, res);
789 break;
790 }
791
792 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
793 case T_INT: case T_FLOAT: // 4 bytes.
794 assert(value->type() == T_INT, "Agreement.");
795 val = value->get_int();
796 obj->int_at_put(index, (jint)*((jint*)&val));
797 break;
798
799 case T_SHORT: case T_CHAR: // 2 bytes
800 assert(value->type() == T_INT, "Agreement.");
801 val = value->get_int();
802 obj->short_at_put(index, (jshort)*((jint*)&val));
803 break;
804
805 case T_BOOLEAN: case T_BYTE: // 1 byte
806 assert(value->type() == T_INT, "Agreement.");
807 val = value->get_int();
808 obj->bool_at_put(index, (jboolean)*((jint*)&val));
809 break;
810
811 default:
812 ShouldNotReachHere();
813 }
814 index++;
815 }
816 }
817
818
819 // restore fields of an eliminated object array
820 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
821 for (int i = 0; i < sv->field_size(); i++) {
822 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
823 assert(value->type() == T_OBJECT, "object element expected");
824 obj->obj_at_put(i, value->get_obj()());
825 }
826 }
827
828
829 // restore fields of all eliminated objects and arrays
830 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
831 for (int i = 0; i < objects->length(); i++) {
832 ObjectValue* sv = (ObjectValue*) objects->at(i);
833 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
834 Handle obj = sv->value();
835 assert(obj.not_null(), "reallocation was missed");
836
837 if (k->oop_is_instance()) {
838 instanceKlass* ik = instanceKlass::cast(k());
839 FieldReassigner reassign(fr, reg_map, sv, obj());
840 ik->do_nonstatic_fields(&reassign);
841 } else if (k->oop_is_typeArray()) {
842 typeArrayKlass* ak = typeArrayKlass::cast(k());
843 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
844 } else if (k->oop_is_objArray()) {
845 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
846 }
847 }
848 }
849
850
851 // relock objects for which synchronization was eliminated
852 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
853 for (int i = 0; i < monitors->length(); i++) {
854 MonitorInfo* mon_info = monitors->at(i);
855 if (mon_info->eliminated()) {
856 assert(mon_info->owner() != NULL, "reallocation was missed");
857 Handle obj = Handle(mon_info->owner());
858 markOop mark = obj->mark();
859 if (UseBiasedLocking && mark->has_bias_pattern()) {
860 // New allocated objects may have the mark set to anonymously biased.
861 // Also the deoptimized method may called methods with synchronization
862 // where the thread-local object is bias locked to the current thread.
863 assert(mark->is_biased_anonymously() ||
864 mark->biased_locker() == thread, "should be locked to current thread");
865 // Reset mark word to unbiased prototype.
866 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
867 obj->set_mark(unbiased_prototype);
868 }
869 BasicLock* lock = mon_info->lock();
870 ObjectSynchronizer::slow_enter(obj, lock, thread);
871 }
872 assert(mon_info->owner()->is_locked(), "object must be locked now");
873 }
874 }
875
876
877 #ifndef PRODUCT
878 // print information about reallocated objects
879 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
880 fieldDescriptor fd;
881
882 for (int i = 0; i < objects->length(); i++) {
883 ObjectValue* sv = (ObjectValue*) objects->at(i);
884 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
885 Handle obj = sv->value();
886
887 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
888 k->as_klassOop()->print_value();
889 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
890 tty->cr();
891
892 if (Verbose) {
893 k->oop_print_on(obj(), tty);
894 }
895 }
896 }
897 #endif
898 #endif // COMPILER2
899
900 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
901
902 #ifndef PRODUCT
903 if (TraceDeoptimization) {
904 ttyLocker ttyl;
905 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
906 fr.print_on(tty);
907 tty->print_cr(" Virtual frames (innermost first):");
908 for (int index = 0; index < chunk->length(); index++) {
909 compiledVFrame* vf = chunk->at(index);
910 tty->print(" %2d - ", index);
911 vf->print_value();
912 int bci = chunk->at(index)->raw_bci();
913 const char* code_name;
914 if (bci == SynchronizationEntryBCI) {
915 code_name = "sync entry";
916 } else {
917 Bytecodes::Code code = Bytecodes::code_at(vf->method(), bci);
918 code_name = Bytecodes::name(code);
919 }
920 tty->print(" - %s", code_name);
921 tty->print_cr(" @ bci %d ", bci);
922 if (Verbose) {
923 vf->print();
924 tty->cr();
925 }
926 }
927 }
928 #endif
929
930 // Register map for next frame (used for stack crawl). We capture
931 // the state of the deopt'ing frame's caller. Thus if we need to
932 // stuff a C2I adapter we can properly fill in the callee-save
933 // register locations.
934 frame caller = fr.sender(reg_map);
935 int frame_size = caller.sp() - fr.sp();
936
937 frame sender = caller;
938
939 // Since the Java thread being deoptimized will eventually adjust it's own stack,
940 // the vframeArray containing the unpacking information is allocated in the C heap.
941 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
942 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
943
944 // Compare the vframeArray to the collected vframes
945 assert(array->structural_compare(thread, chunk), "just checking");
946 Events::log("# vframes = %d", (intptr_t)chunk->length());
947
948 #ifndef PRODUCT
949 if (TraceDeoptimization) {
950 ttyLocker ttyl;
951 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
952 }
953 #endif // PRODUCT
954
955 return array;
956 }
957
958
959 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
960 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
961 for (int i = 0; i < monitors->length(); i++) {
962 MonitorInfo* mon_info = monitors->at(i);
963 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
964 objects_to_revoke->append(Handle(mon_info->owner()));
965 }
966 }
967 }
968
969
970 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
971 if (!UseBiasedLocking) {
972 return;
973 }
974
975 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
976
977 // Unfortunately we don't have a RegisterMap available in most of
978 // the places we want to call this routine so we need to walk the
979 // stack again to update the register map.
980 if (map == NULL || !map->update_map()) {
981 StackFrameStream sfs(thread, true);
982 bool found = false;
983 while (!found && !sfs.is_done()) {
984 frame* cur = sfs.current();
985 sfs.next();
986 found = cur->id() == fr.id();
987 }
988 assert(found, "frame to be deoptimized not found on target thread's stack");
989 map = sfs.register_map();
990 }
991
992 vframe* vf = vframe::new_vframe(&fr, map, thread);
993 compiledVFrame* cvf = compiledVFrame::cast(vf);
994 // Revoke monitors' biases in all scopes
995 while (!cvf->is_top()) {
996 collect_monitors(cvf, objects_to_revoke);
997 cvf = compiledVFrame::cast(cvf->sender());
998 }
999 collect_monitors(cvf, objects_to_revoke);
1000
1001 if (SafepointSynchronize::is_at_safepoint()) {
1002 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1003 } else {
1004 BiasedLocking::revoke(objects_to_revoke);
1005 }
1006 }
1007
1008
1009 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1010 if (!UseBiasedLocking) {
1011 return;
1012 }
1013
1014 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1015 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1016 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1017 if (jt->has_last_Java_frame()) {
1018 StackFrameStream sfs(jt, true);
1019 while (!sfs.is_done()) {
1020 frame* cur = sfs.current();
1021 if (cb->contains(cur->pc())) {
1022 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1023 compiledVFrame* cvf = compiledVFrame::cast(vf);
1024 // Revoke monitors' biases in all scopes
1025 while (!cvf->is_top()) {
1026 collect_monitors(cvf, objects_to_revoke);
1027 cvf = compiledVFrame::cast(cvf->sender());
1028 }
1029 collect_monitors(cvf, objects_to_revoke);
1030 }
1031 sfs.next();
1032 }
1033 }
1034 }
1035 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1036 }
1037
1038
1039 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1040 assert(fr.can_be_deoptimized(), "checking frame type");
1041
1042 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1043
1044 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1045
1046 // Patch the nmethod so that when execution returns to it we will
1047 // deopt the execution state and return to the interpreter.
1048 fr.deoptimize(thread);
1049 }
1050
1051 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1052 // Deoptimize only if the frame comes from compile code.
1053 // Do not deoptimize the frame which is already patched
1054 // during the execution of the loops below.
1055 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1056 return;
1057 }
1058 ResourceMark rm;
1059 DeoptimizationMarker dm;
1060 if (UseBiasedLocking) {
1061 revoke_biases_of_monitors(thread, fr, map);
1062 }
1063 deoptimize_single_frame(thread, fr);
1064
1065 }
1066
1067
1068 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1069 // Compute frame and register map based on thread and sp.
1070 RegisterMap reg_map(thread, UseBiasedLocking);
1071 frame fr = thread->last_frame();
1072 while (fr.id() != id) {
1073 fr = fr.sender(®_map);
1074 }
1075 deoptimize(thread, fr, ®_map);
1076 }
1077
1078
1079 // JVMTI PopFrame support
1080 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1081 {
1082 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1083 }
1084 JRT_END
1085
1086
1087 #if defined(COMPILER2) || defined(SHARK)
1088 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1089 // in case of an unresolved klass entry, load the class.
1090 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1091 klassOop tk = constant_pool->klass_at(index, CHECK);
1092 return;
1093 }
1094
1095 if (!constant_pool->tag_at(index).is_symbol()) return;
1096
1097 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1098 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1099
1100 // class name?
1101 if (symbol->byte_at(0) != '(') {
1102 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1103 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1104 return;
1105 }
1106
1107 // then it must be a signature!
1108 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1109 if (ss.is_object()) {
1110 symbolOop s = ss.as_symbol(CHECK);
1111 symbolHandle class_name (THREAD, s);
1112 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1113 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1114 }
1115 }
1116 }
1117
1118
1119 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1120 EXCEPTION_MARK;
1121 load_class_by_index(constant_pool, index, THREAD);
1122 if (HAS_PENDING_EXCEPTION) {
1123 // Exception happened during classloading. We ignore the exception here, since it
1124 // is going to be rethrown since the current activation is going to be deoptimzied and
1125 // the interpreter will re-execute the bytecode.
1126 CLEAR_PENDING_EXCEPTION;
1127 }
1128 }
1129
1130 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1131 HandleMark hm;
1132
1133 // uncommon_trap() is called at the beginning of the uncommon trap
1134 // handler. Note this fact before we start generating temporary frames
1135 // that can confuse an asynchronous stack walker. This counter is
1136 // decremented at the end of unpack_frames().
1137 thread->inc_in_deopt_handler();
1138
1139 // We need to update the map if we have biased locking.
1140 RegisterMap reg_map(thread, UseBiasedLocking);
1141 frame stub_frame = thread->last_frame();
1142 frame fr = stub_frame.sender(®_map);
1143 // Make sure the calling nmethod is not getting deoptimized and removed
1144 // before we are done with it.
1145 nmethodLocker nl(fr.pc());
1146
1147 {
1148 ResourceMark rm;
1149
1150 // Revoke biases of any monitors in the frame to ensure we can migrate them
1151 revoke_biases_of_monitors(thread, fr, ®_map);
1152
1153 DeoptReason reason = trap_request_reason(trap_request);
1154 DeoptAction action = trap_request_action(trap_request);
1155 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1156
1157 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1158 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1159 compiledVFrame* cvf = compiledVFrame::cast(vf);
1160
1161 nmethod* nm = cvf->code();
1162
1163 ScopeDesc* trap_scope = cvf->scope();
1164 methodHandle trap_method = trap_scope->method();
1165 int trap_bci = trap_scope->bci();
1166 Bytecodes::Code trap_bc = Bytecode_at(trap_method->bcp_from(trap_bci))->java_code();
1167
1168 // Record this event in the histogram.
1169 gather_statistics(reason, action, trap_bc);
1170
1171 // Ensure that we can record deopt. history:
1172 bool create_if_missing = ProfileTraps;
1173
1174 methodDataHandle trap_mdo
1175 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1176
1177 // Print a bunch of diagnostics, if requested.
1178 if (TraceDeoptimization || LogCompilation) {
1179 ResourceMark rm;
1180 ttyLocker ttyl;
1181 char buf[100];
1182 if (xtty != NULL) {
1183 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1184 os::current_thread_id(),
1185 format_trap_request(buf, sizeof(buf), trap_request));
1186 nm->log_identity(xtty);
1187 }
1188 symbolHandle class_name;
1189 bool unresolved = false;
1190 if (unloaded_class_index >= 0) {
1191 constantPoolHandle constants (THREAD, trap_method->constants());
1192 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1193 class_name = symbolHandle(THREAD,
1194 constants->klass_name_at(unloaded_class_index));
1195 unresolved = true;
1196 if (xtty != NULL)
1197 xtty->print(" unresolved='1'");
1198 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1199 class_name = symbolHandle(THREAD,
1200 constants->symbol_at(unloaded_class_index));
1201 }
1202 if (xtty != NULL)
1203 xtty->name(class_name);
1204 }
1205 if (xtty != NULL && trap_mdo.not_null()) {
1206 // Dump the relevant MDO state.
1207 // This is the deopt count for the current reason, any previous
1208 // reasons or recompiles seen at this point.
1209 int dcnt = trap_mdo->trap_count(reason);
1210 if (dcnt != 0)
1211 xtty->print(" count='%d'", dcnt);
1212 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1213 int dos = (pdata == NULL)? 0: pdata->trap_state();
1214 if (dos != 0) {
1215 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1216 if (trap_state_is_recompiled(dos)) {
1217 int recnt2 = trap_mdo->overflow_recompile_count();
1218 if (recnt2 != 0)
1219 xtty->print(" recompiles2='%d'", recnt2);
1220 }
1221 }
1222 }
1223 if (xtty != NULL) {
1224 xtty->stamp();
1225 xtty->end_head();
1226 }
1227 if (TraceDeoptimization) { // make noise on the tty
1228 tty->print("Uncommon trap occurred in");
1229 nm->method()->print_short_name(tty);
1230 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1231 fr.pc(),
1232 (int) os::current_thread_id(),
1233 trap_reason_name(reason),
1234 trap_action_name(action),
1235 unloaded_class_index);
1236 if (class_name.not_null()) {
1237 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1238 class_name->print_symbol_on(tty);
1239 }
1240 tty->cr();
1241 }
1242 if (xtty != NULL) {
1243 // Log the precise location of the trap.
1244 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1245 xtty->begin_elem("jvms bci='%d'", sd->bci());
1246 xtty->method(sd->method());
1247 xtty->end_elem();
1248 if (sd->is_top()) break;
1249 }
1250 xtty->tail("uncommon_trap");
1251 }
1252 }
1253 // (End diagnostic printout.)
1254
1255 // Load class if necessary
1256 if (unloaded_class_index >= 0) {
1257 constantPoolHandle constants(THREAD, trap_method->constants());
1258 load_class_by_index(constants, unloaded_class_index);
1259 }
1260
1261 // Flush the nmethod if necessary and desirable.
1262 //
1263 // We need to avoid situations where we are re-flushing the nmethod
1264 // because of a hot deoptimization site. Repeated flushes at the same
1265 // point need to be detected by the compiler and avoided. If the compiler
1266 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1267 // module must take measures to avoid an infinite cycle of recompilation
1268 // and deoptimization. There are several such measures:
1269 //
1270 // 1. If a recompilation is ordered a second time at some site X
1271 // and for the same reason R, the action is adjusted to 'reinterpret',
1272 // to give the interpreter time to exercise the method more thoroughly.
1273 // If this happens, the method's overflow_recompile_count is incremented.
1274 //
1275 // 2. If the compiler fails to reduce the deoptimization rate, then
1276 // the method's overflow_recompile_count will begin to exceed the set
1277 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1278 // is adjusted to 'make_not_compilable', and the method is abandoned
1279 // to the interpreter. This is a performance hit for hot methods,
1280 // but is better than a disastrous infinite cycle of recompilations.
1281 // (Actually, only the method containing the site X is abandoned.)
1282 //
1283 // 3. In parallel with the previous measures, if the total number of
1284 // recompilations of a method exceeds the much larger set limit
1285 // PerMethodRecompilationCutoff, the method is abandoned.
1286 // This should only happen if the method is very large and has
1287 // many "lukewarm" deoptimizations. The code which enforces this
1288 // limit is elsewhere (class nmethod, class methodOopDesc).
1289 //
1290 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1291 // to recompile at each bytecode independently of the per-BCI cutoff.
1292 //
1293 // The decision to update code is up to the compiler, and is encoded
1294 // in the Action_xxx code. If the compiler requests Action_none
1295 // no trap state is changed, no compiled code is changed, and the
1296 // computation suffers along in the interpreter.
1297 //
1298 // The other action codes specify various tactics for decompilation
1299 // and recompilation. Action_maybe_recompile is the loosest, and
1300 // allows the compiled code to stay around until enough traps are seen,
1301 // and until the compiler gets around to recompiling the trapping method.
1302 //
1303 // The other actions cause immediate removal of the present code.
1304
1305 bool update_trap_state = true;
1306 bool make_not_entrant = false;
1307 bool make_not_compilable = false;
1308 bool reprofile = false;
1309 switch (action) {
1310 case Action_none:
1311 // Keep the old code.
1312 update_trap_state = false;
1313 break;
1314 case Action_maybe_recompile:
1315 // Do not need to invalidate the present code, but we can
1316 // initiate another
1317 // Start compiler without (necessarily) invalidating the nmethod.
1318 // The system will tolerate the old code, but new code should be
1319 // generated when possible.
1320 break;
1321 case Action_reinterpret:
1322 // Go back into the interpreter for a while, and then consider
1323 // recompiling form scratch.
1324 make_not_entrant = true;
1325 // Reset invocation counter for outer most method.
1326 // This will allow the interpreter to exercise the bytecodes
1327 // for a while before recompiling.
1328 // By contrast, Action_make_not_entrant is immediate.
1329 //
1330 // Note that the compiler will track null_check, null_assert,
1331 // range_check, and class_check events and log them as if they
1332 // had been traps taken from compiled code. This will update
1333 // the MDO trap history so that the next compilation will
1334 // properly detect hot trap sites.
1335 reprofile = true;
1336 break;
1337 case Action_make_not_entrant:
1338 // Request immediate recompilation, and get rid of the old code.
1339 // Make them not entrant, so next time they are called they get
1340 // recompiled. Unloaded classes are loaded now so recompile before next
1341 // time they are called. Same for uninitialized. The interpreter will
1342 // link the missing class, if any.
1343 make_not_entrant = true;
1344 break;
1345 case Action_make_not_compilable:
1346 // Give up on compiling this method at all.
1347 make_not_entrant = true;
1348 make_not_compilable = true;
1349 break;
1350 default:
1351 ShouldNotReachHere();
1352 }
1353
1354 // Setting +ProfileTraps fixes the following, on all platforms:
1355 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1356 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1357 // recompile relies on a methodDataOop to record heroic opt failures.
1358
1359 // Whether the interpreter is producing MDO data or not, we also need
1360 // to use the MDO to detect hot deoptimization points and control
1361 // aggressive optimization.
1362 bool inc_recompile_count = false;
1363 ProfileData* pdata = NULL;
1364 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1365 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1366 uint this_trap_count = 0;
1367 bool maybe_prior_trap = false;
1368 bool maybe_prior_recompile = false;
1369 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1370 //outputs:
1371 this_trap_count,
1372 maybe_prior_trap,
1373 maybe_prior_recompile);
1374 // Because the interpreter also counts null, div0, range, and class
1375 // checks, these traps from compiled code are double-counted.
1376 // This is harmless; it just means that the PerXTrapLimit values
1377 // are in effect a little smaller than they look.
1378
1379 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1380 if (per_bc_reason != Reason_none) {
1381 // Now take action based on the partially known per-BCI history.
1382 if (maybe_prior_trap
1383 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1384 // If there are too many traps at this BCI, force a recompile.
1385 // This will allow the compiler to see the limit overflow, and
1386 // take corrective action, if possible. The compiler generally
1387 // does not use the exact PerBytecodeTrapLimit value, but instead
1388 // changes its tactics if it sees any traps at all. This provides
1389 // a little hysteresis, delaying a recompile until a trap happens
1390 // several times.
1391 //
1392 // Actually, since there is only one bit of counter per BCI,
1393 // the possible per-BCI counts are {0,1,(per-method count)}.
1394 // This produces accurate results if in fact there is only
1395 // one hot trap site, but begins to get fuzzy if there are
1396 // many sites. For example, if there are ten sites each
1397 // trapping two or more times, they each get the blame for
1398 // all of their traps.
1399 make_not_entrant = true;
1400 }
1401
1402 // Detect repeated recompilation at the same BCI, and enforce a limit.
1403 if (make_not_entrant && maybe_prior_recompile) {
1404 // More than one recompile at this point.
1405 inc_recompile_count = maybe_prior_trap;
1406 }
1407 } else {
1408 // For reasons which are not recorded per-bytecode, we simply
1409 // force recompiles unconditionally.
1410 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1411 make_not_entrant = true;
1412 }
1413
1414 // Go back to the compiler if there are too many traps in this method.
1415 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1416 // If there are too many traps in this method, force a recompile.
1417 // This will allow the compiler to see the limit overflow, and
1418 // take corrective action, if possible.
1419 // (This condition is an unlikely backstop only, because the
1420 // PerBytecodeTrapLimit is more likely to take effect first,
1421 // if it is applicable.)
1422 make_not_entrant = true;
1423 }
1424
1425 // Here's more hysteresis: If there has been a recompile at
1426 // this trap point already, run the method in the interpreter
1427 // for a while to exercise it more thoroughly.
1428 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1429 reprofile = true;
1430 }
1431
1432 }
1433
1434 // Take requested actions on the method:
1435
1436 // Recompile
1437 if (make_not_entrant) {
1438 if (!nm->make_not_entrant()) {
1439 return; // the call did not change nmethod's state
1440 }
1441
1442 if (pdata != NULL) {
1443 // Record the recompilation event, if any.
1444 int tstate0 = pdata->trap_state();
1445 int tstate1 = trap_state_set_recompiled(tstate0, true);
1446 if (tstate1 != tstate0)
1447 pdata->set_trap_state(tstate1);
1448 }
1449 }
1450
1451 if (inc_recompile_count) {
1452 trap_mdo->inc_overflow_recompile_count();
1453 if ((uint)trap_mdo->overflow_recompile_count() >
1454 (uint)PerBytecodeRecompilationCutoff) {
1455 // Give up on the method containing the bad BCI.
1456 if (trap_method() == nm->method()) {
1457 make_not_compilable = true;
1458 } else {
1459 trap_method->set_not_compilable(CompLevel_full_optimization);
1460 // But give grace to the enclosing nm->method().
1461 }
1462 }
1463 }
1464
1465 // Reprofile
1466 if (reprofile) {
1467 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1468 }
1469
1470 // Give up compiling
1471 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1472 assert(make_not_entrant, "consistent");
1473 nm->method()->set_not_compilable(CompLevel_full_optimization);
1474 }
1475
1476 } // Free marked resources
1477
1478 }
1479 JRT_END
1480
1481 methodDataOop
1482 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1483 bool create_if_missing) {
1484 Thread* THREAD = thread;
1485 methodDataOop mdo = m()->method_data();
1486 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1487 // Build an MDO. Ignore errors like OutOfMemory;
1488 // that simply means we won't have an MDO to update.
1489 methodOopDesc::build_interpreter_method_data(m, THREAD);
1490 if (HAS_PENDING_EXCEPTION) {
1491 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1492 CLEAR_PENDING_EXCEPTION;
1493 }
1494 mdo = m()->method_data();
1495 }
1496 return mdo;
1497 }
1498
1499 ProfileData*
1500 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1501 int trap_bci,
1502 Deoptimization::DeoptReason reason,
1503 //outputs:
1504 uint& ret_this_trap_count,
1505 bool& ret_maybe_prior_trap,
1506 bool& ret_maybe_prior_recompile) {
1507 uint prior_trap_count = trap_mdo->trap_count(reason);
1508 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1509
1510 // If the runtime cannot find a place to store trap history,
1511 // it is estimated based on the general condition of the method.
1512 // If the method has ever been recompiled, or has ever incurred
1513 // a trap with the present reason , then this BCI is assumed
1514 // (pessimistically) to be the culprit.
1515 bool maybe_prior_trap = (prior_trap_count != 0);
1516 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1517 ProfileData* pdata = NULL;
1518
1519
1520 // For reasons which are recorded per bytecode, we check per-BCI data.
1521 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1522 if (per_bc_reason != Reason_none) {
1523 // Find the profile data for this BCI. If there isn't one,
1524 // try to allocate one from the MDO's set of spares.
1525 // This will let us detect a repeated trap at this point.
1526 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1527
1528 if (pdata != NULL) {
1529 // Query the trap state of this profile datum.
1530 int tstate0 = pdata->trap_state();
1531 if (!trap_state_has_reason(tstate0, per_bc_reason))
1532 maybe_prior_trap = false;
1533 if (!trap_state_is_recompiled(tstate0))
1534 maybe_prior_recompile = false;
1535
1536 // Update the trap state of this profile datum.
1537 int tstate1 = tstate0;
1538 // Record the reason.
1539 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1540 // Store the updated state on the MDO, for next time.
1541 if (tstate1 != tstate0)
1542 pdata->set_trap_state(tstate1);
1543 } else {
1544 if (LogCompilation && xtty != NULL) {
1545 ttyLocker ttyl;
1546 // Missing MDP? Leave a small complaint in the log.
1547 xtty->elem("missing_mdp bci='%d'", trap_bci);
1548 }
1549 }
1550 }
1551
1552 // Return results:
1553 ret_this_trap_count = this_trap_count;
1554 ret_maybe_prior_trap = maybe_prior_trap;
1555 ret_maybe_prior_recompile = maybe_prior_recompile;
1556 return pdata;
1557 }
1558
1559 void
1560 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1561 ResourceMark rm;
1562 // Ignored outputs:
1563 uint ignore_this_trap_count;
1564 bool ignore_maybe_prior_trap;
1565 bool ignore_maybe_prior_recompile;
1566 query_update_method_data(trap_mdo, trap_bci,
1567 (DeoptReason)reason,
1568 ignore_this_trap_count,
1569 ignore_maybe_prior_trap,
1570 ignore_maybe_prior_recompile);
1571 }
1572
1573 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1574
1575 // Still in Java no safepoints
1576 {
1577 // This enters VM and may safepoint
1578 uncommon_trap_inner(thread, trap_request);
1579 }
1580 return fetch_unroll_info_helper(thread);
1581 }
1582
1583 // Local derived constants.
1584 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1585 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1586 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1587
1588 //---------------------------trap_state_reason---------------------------------
1589 Deoptimization::DeoptReason
1590 Deoptimization::trap_state_reason(int trap_state) {
1591 // This assert provides the link between the width of DataLayout::trap_bits
1592 // and the encoding of "recorded" reasons. It ensures there are enough
1593 // bits to store all needed reasons in the per-BCI MDO profile.
1594 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1595 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1596 trap_state -= recompile_bit;
1597 if (trap_state == DS_REASON_MASK) {
1598 return Reason_many;
1599 } else {
1600 assert((int)Reason_none == 0, "state=0 => Reason_none");
1601 return (DeoptReason)trap_state;
1602 }
1603 }
1604 //-------------------------trap_state_has_reason-------------------------------
1605 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1606 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1607 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1608 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1609 trap_state -= recompile_bit;
1610 if (trap_state == DS_REASON_MASK) {
1611 return -1; // true, unspecifically (bottom of state lattice)
1612 } else if (trap_state == reason) {
1613 return 1; // true, definitely
1614 } else if (trap_state == 0) {
1615 return 0; // false, definitely (top of state lattice)
1616 } else {
1617 return 0; // false, definitely
1618 }
1619 }
1620 //-------------------------trap_state_add_reason-------------------------------
1621 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1622 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1623 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1624 trap_state -= recompile_bit;
1625 if (trap_state == DS_REASON_MASK) {
1626 return trap_state + recompile_bit; // already at state lattice bottom
1627 } else if (trap_state == reason) {
1628 return trap_state + recompile_bit; // the condition is already true
1629 } else if (trap_state == 0) {
1630 return reason + recompile_bit; // no condition has yet been true
1631 } else {
1632 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1633 }
1634 }
1635 //-----------------------trap_state_is_recompiled------------------------------
1636 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1637 return (trap_state & DS_RECOMPILE_BIT) != 0;
1638 }
1639 //-----------------------trap_state_set_recompiled-----------------------------
1640 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1641 if (z) return trap_state | DS_RECOMPILE_BIT;
1642 else return trap_state & ~DS_RECOMPILE_BIT;
1643 }
1644 //---------------------------format_trap_state---------------------------------
1645 // This is used for debugging and diagnostics, including hotspot.log output.
1646 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1647 int trap_state) {
1648 DeoptReason reason = trap_state_reason(trap_state);
1649 bool recomp_flag = trap_state_is_recompiled(trap_state);
1650 // Re-encode the state from its decoded components.
1651 int decoded_state = 0;
1652 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1653 decoded_state = trap_state_add_reason(decoded_state, reason);
1654 if (recomp_flag)
1655 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1656 // If the state re-encodes properly, format it symbolically.
1657 // Because this routine is used for debugging and diagnostics,
1658 // be robust even if the state is a strange value.
1659 size_t len;
1660 if (decoded_state != trap_state) {
1661 // Random buggy state that doesn't decode??
1662 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1663 } else {
1664 len = jio_snprintf(buf, buflen, "%s%s",
1665 trap_reason_name(reason),
1666 recomp_flag ? " recompiled" : "");
1667 }
1668 if (len >= buflen)
1669 buf[buflen-1] = '\0';
1670 return buf;
1671 }
1672
1673
1674 //--------------------------------statics--------------------------------------
1675 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1676 = Deoptimization::Action_reinterpret;
1677 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1678 // Note: Keep this in sync. with enum DeoptReason.
1679 "none",
1680 "null_check",
1681 "null_assert",
1682 "range_check",
1683 "class_check",
1684 "array_check",
1685 "intrinsic",
1686 "bimorphic",
1687 "unloaded",
1688 "uninitialized",
1689 "unreached",
1690 "unhandled",
1691 "constraint",
1692 "div0_check",
1693 "age",
1694 "predicate"
1695 };
1696 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1697 // Note: Keep this in sync. with enum DeoptAction.
1698 "none",
1699 "maybe_recompile",
1700 "reinterpret",
1701 "make_not_entrant",
1702 "make_not_compilable"
1703 };
1704
1705 const char* Deoptimization::trap_reason_name(int reason) {
1706 if (reason == Reason_many) return "many";
1707 if ((uint)reason < Reason_LIMIT)
1708 return _trap_reason_name[reason];
1709 static char buf[20];
1710 sprintf(buf, "reason%d", reason);
1711 return buf;
1712 }
1713 const char* Deoptimization::trap_action_name(int action) {
1714 if ((uint)action < Action_LIMIT)
1715 return _trap_action_name[action];
1716 static char buf[20];
1717 sprintf(buf, "action%d", action);
1718 return buf;
1719 }
1720
1721 // This is used for debugging and diagnostics, including hotspot.log output.
1722 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1723 int trap_request) {
1724 jint unloaded_class_index = trap_request_index(trap_request);
1725 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1726 const char* action = trap_action_name(trap_request_action(trap_request));
1727 size_t len;
1728 if (unloaded_class_index < 0) {
1729 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1730 reason, action);
1731 } else {
1732 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1733 reason, action, unloaded_class_index);
1734 }
1735 if (len >= buflen)
1736 buf[buflen-1] = '\0';
1737 return buf;
1738 }
1739
1740 juint Deoptimization::_deoptimization_hist
1741 [Deoptimization::Reason_LIMIT]
1742 [1 + Deoptimization::Action_LIMIT]
1743 [Deoptimization::BC_CASE_LIMIT]
1744 = {0};
1745
1746 enum {
1747 LSB_BITS = 8,
1748 LSB_MASK = right_n_bits(LSB_BITS)
1749 };
1750
1751 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1752 Bytecodes::Code bc) {
1753 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1754 assert(action >= 0 && action < Action_LIMIT, "oob");
1755 _deoptimization_hist[Reason_none][0][0] += 1; // total
1756 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1757 juint* cases = _deoptimization_hist[reason][1+action];
1758 juint* bc_counter_addr = NULL;
1759 juint bc_counter = 0;
1760 // Look for an unused counter, or an exact match to this BC.
1761 if (bc != Bytecodes::_illegal) {
1762 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1763 juint* counter_addr = &cases[bc_case];
1764 juint counter = *counter_addr;
1765 if ((counter == 0 && bc_counter_addr == NULL)
1766 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1767 // this counter is either free or is already devoted to this BC
1768 bc_counter_addr = counter_addr;
1769 bc_counter = counter | bc;
1770 }
1771 }
1772 }
1773 if (bc_counter_addr == NULL) {
1774 // Overflow, or no given bytecode.
1775 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1776 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1777 }
1778 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1779 }
1780
1781 jint Deoptimization::total_deoptimization_count() {
1782 return _deoptimization_hist[Reason_none][0][0];
1783 }
1784
1785 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1786 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1787 return _deoptimization_hist[reason][0][0];
1788 }
1789
1790 void Deoptimization::print_statistics() {
1791 juint total = total_deoptimization_count();
1792 juint account = total;
1793 if (total != 0) {
1794 ttyLocker ttyl;
1795 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1796 tty->print_cr("Deoptimization traps recorded:");
1797 #define PRINT_STAT_LINE(name, r) \
1798 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1799 PRINT_STAT_LINE("total", total);
1800 // For each non-zero entry in the histogram, print the reason,
1801 // the action, and (if specifically known) the type of bytecode.
1802 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1803 for (int action = 0; action < Action_LIMIT; action++) {
1804 juint* cases = _deoptimization_hist[reason][1+action];
1805 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1806 juint counter = cases[bc_case];
1807 if (counter != 0) {
1808 char name[1*K];
1809 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1810 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1811 bc = Bytecodes::_illegal;
1812 sprintf(name, "%s/%s/%s",
1813 trap_reason_name(reason),
1814 trap_action_name(action),
1815 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1816 juint r = counter >> LSB_BITS;
1817 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1818 account -= r;
1819 }
1820 }
1821 }
1822 }
1823 if (account != 0) {
1824 PRINT_STAT_LINE("unaccounted", account);
1825 }
1826 #undef PRINT_STAT_LINE
1827 if (xtty != NULL) xtty->tail("statistics");
1828 }
1829 }
1830 #else // COMPILER2 || SHARK
1831
1832
1833 // Stubs for C1 only system.
1834 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1835 return false;
1836 }
1837
1838 const char* Deoptimization::trap_reason_name(int reason) {
1839 return "unknown";
1840 }
1841
1842 void Deoptimization::print_statistics() {
1843 // no output
1844 }
1845
1846 void
1847 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1848 // no udpate
1849 }
1850
1851 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1852 return 0;
1853 }
1854
1855 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1856 Bytecodes::Code bc) {
1857 // no update
1858 }
1859
1860 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1861 int trap_state) {
1862 jio_snprintf(buf, buflen, "#%d", trap_state);
1863 return buf;
1864 }
1865
1866 #endif // COMPILER2 || SHARK