1 /*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/method.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef TARGET_ARCH_arm
63 # include "vmreg_arm.inline.hpp"
64 #endif
65 #ifdef TARGET_ARCH_ppc
66 # include "vmreg_ppc.inline.hpp"
67 #endif
68 #ifdef COMPILER2
69 #ifdef TARGET_ARCH_MODEL_x86_32
70 # include "adfiles/ad_x86_32.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_x86_64
73 # include "adfiles/ad_x86_64.hpp"
74 #endif
75 #ifdef TARGET_ARCH_MODEL_sparc
76 # include "adfiles/ad_sparc.hpp"
77 #endif
78 #ifdef TARGET_ARCH_MODEL_zero
79 # include "adfiles/ad_zero.hpp"
80 #endif
81 #ifdef TARGET_ARCH_MODEL_arm
82 # include "adfiles/ad_arm.hpp"
83 #endif
84 #ifdef TARGET_ARCH_MODEL_ppc_32
85 # include "adfiles/ad_ppc_32.hpp"
86 #endif
87 #ifdef TARGET_ARCH_MODEL_ppc_64
88 # include "adfiles/ad_ppc_64.hpp"
89 #endif
90 #endif // COMPILER2
91
92 bool DeoptimizationMarker::_is_active = false;
93
94 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
95 int caller_adjustment,
96 int caller_actual_parameters,
97 int number_of_frames,
98 intptr_t* frame_sizes,
99 address* frame_pcs,
100 BasicType return_type) {
101 _size_of_deoptimized_frame = size_of_deoptimized_frame;
102 _caller_adjustment = caller_adjustment;
103 _caller_actual_parameters = caller_actual_parameters;
104 _number_of_frames = number_of_frames;
105 _frame_sizes = frame_sizes;
106 _frame_pcs = frame_pcs;
107 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
108 _return_type = return_type;
109 _initial_info = 0;
110 // PD (x86 only)
111 _counter_temp = 0;
112 _unpack_kind = 0;
113 _sender_sp_temp = 0;
114
115 _total_frame_sizes = size_of_frames();
116 }
117
118
119 Deoptimization::UnrollBlock::~UnrollBlock() {
120 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
121 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
122 FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
123 }
124
125
126 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
127 assert(register_number < RegisterMap::reg_count, "checking register number");
128 return &_register_block[register_number * 2];
129 }
130
131
132
133 int Deoptimization::UnrollBlock::size_of_frames() const {
134 // Acount first for the adjustment of the initial frame
135 int result = _caller_adjustment;
136 for (int index = 0; index < number_of_frames(); index++) {
137 result += frame_sizes()[index];
138 }
139 return result;
140 }
141
142
143 void Deoptimization::UnrollBlock::print() {
144 ttyLocker ttyl;
145 tty->print_cr("UnrollBlock");
146 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
147 tty->print( " frame_sizes: ");
148 for (int index = 0; index < number_of_frames(); index++) {
149 tty->print("%d ", frame_sizes()[index]);
150 }
151 tty->cr();
152 }
153
154
155 // In order to make fetch_unroll_info work properly with escape
156 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
157 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
158 // of previously eliminated objects occurs in realloc_objects, which is
159 // called from the method fetch_unroll_info_helper below.
160 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
161 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
162 // but makes the entry a little slower. There is however a little dance we have to
163 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
164
165 // fetch_unroll_info() is called at the beginning of the deoptimization
166 // handler. Note this fact before we start generating temporary frames
167 // that can confuse an asynchronous stack walker. This counter is
168 // decremented at the end of unpack_frames().
169 thread->inc_in_deopt_handler();
170
171 return fetch_unroll_info_helper(thread);
172 JRT_END
173
174
175 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
176 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
177
178 // Note: there is a safepoint safety issue here. No matter whether we enter
179 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
180 // the vframeArray is created.
181 //
182
183 // Allocate our special deoptimization ResourceMark
184 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
185 assert(thread->deopt_mark() == NULL, "Pending deopt!");
186 thread->set_deopt_mark(dmark);
187
188 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
189 RegisterMap map(thread, true);
190 RegisterMap dummy_map(thread, false);
191 // Now get the deoptee with a valid map
192 frame deoptee = stub_frame.sender(&map);
193 // Set the deoptee nmethod
194 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
195 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
196
197 if (VerifyStack) {
198 thread->validate_frame_layout();
199 }
200
201 // Create a growable array of VFrames where each VFrame represents an inlined
202 // Java frame. This storage is allocated with the usual system arena.
203 assert(deoptee.is_compiled_frame(), "Wrong frame type");
204 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
205 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
206 while (!vf->is_top()) {
207 assert(vf->is_compiled_frame(), "Wrong frame type");
208 chunk->push(compiledVFrame::cast(vf));
209 vf = vf->sender();
210 }
211 assert(vf->is_compiled_frame(), "Wrong frame type");
212 chunk->push(compiledVFrame::cast(vf));
213
214 #ifdef COMPILER2
215 // Reallocate the non-escaping objects and restore their fields. Then
216 // relock objects if synchronization on them was eliminated.
217 if (DoEscapeAnalysis || EliminateNestedLocks) {
218 if (EliminateAllocations) {
219 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
220 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
221
222 // The flag return_oop() indicates call sites which return oop
223 // in compiled code. Such sites include java method calls,
224 // runtime calls (for example, used to allocate new objects/arrays
225 // on slow code path) and any other calls generated in compiled code.
226 // It is not guaranteed that we can get such information here only
227 // by analyzing bytecode in deoptimized frames. This is why this flag
228 // is set during method compilation (see Compile::Process_OopMap_Node()).
229 bool save_oop_result = chunk->at(0)->scope()->return_oop();
230 Handle return_value;
231 if (save_oop_result) {
232 // Reallocation may trigger GC. If deoptimization happened on return from
233 // call which returns oop we need to save it since it is not in oopmap.
234 oop result = deoptee.saved_oop_result(&map);
235 assert(result == NULL || result->is_oop(), "must be oop");
236 return_value = Handle(thread, result);
237 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
238 if (TraceDeoptimization) {
239 ttyLocker ttyl;
240 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
241 }
242 }
243 bool reallocated = false;
244 if (objects != NULL) {
245 JRT_BLOCK
246 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
247 JRT_END
248 }
249 if (reallocated) {
250 reassign_fields(&deoptee, &map, objects);
251 #ifndef PRODUCT
252 if (TraceDeoptimization) {
253 ttyLocker ttyl;
254 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
255 print_objects(objects);
256 }
257 #endif
258 }
259 if (save_oop_result) {
260 // Restore result.
261 deoptee.set_saved_oop_result(&map, return_value());
262 }
263 }
264 if (EliminateLocks) {
265 #ifndef PRODUCT
266 bool first = true;
267 #endif
268 for (int i = 0; i < chunk->length(); i++) {
269 compiledVFrame* cvf = chunk->at(i);
270 assert (cvf->scope() != NULL,"expect only compiled java frames");
271 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
272 if (monitors->is_nonempty()) {
273 relock_objects(monitors, thread);
274 #ifndef PRODUCT
275 if (TraceDeoptimization) {
276 ttyLocker ttyl;
277 for (int j = 0; j < monitors->length(); j++) {
278 MonitorInfo* mi = monitors->at(j);
279 if (mi->eliminated()) {
280 if (first) {
281 first = false;
282 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
283 }
284 tty->print_cr(" object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
285 }
286 }
287 }
288 #endif
289 }
290 }
291 }
292 }
293 #endif // COMPILER2
294 // Ensure that no safepoint is taken after pointers have been stored
295 // in fields of rematerialized objects. If a safepoint occurs from here on
296 // out the java state residing in the vframeArray will be missed.
297 No_Safepoint_Verifier no_safepoint;
298
299 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
300
301 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
302 thread->set_vframe_array_head(array);
303
304 // Now that the vframeArray has been created if we have any deferred local writes
305 // added by jvmti then we can free up that structure as the data is now in the
306 // vframeArray
307
308 if (thread->deferred_locals() != NULL) {
309 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
310 int i = 0;
311 do {
312 // Because of inlining we could have multiple vframes for a single frame
313 // and several of the vframes could have deferred writes. Find them all.
314 if (list->at(i)->id() == array->original().id()) {
315 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
316 list->remove_at(i);
317 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
318 delete dlv;
319 } else {
320 i++;
321 }
322 } while ( i < list->length() );
323 if (list->length() == 0) {
324 thread->set_deferred_locals(NULL);
325 // free the list and elements back to C heap.
326 delete list;
327 }
328
329 }
330
331 #ifndef SHARK
332 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
333 CodeBlob* cb = stub_frame.cb();
334 // Verify we have the right vframeArray
335 assert(cb->frame_size() >= 0, "Unexpected frame size");
336 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
337
338 // If the deopt call site is a MethodHandle invoke call site we have
339 // to adjust the unpack_sp.
340 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
341 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
342 unpack_sp = deoptee.unextended_sp();
343
344 #ifdef ASSERT
345 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
346 #endif
347 #else
348 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
349 #endif // !SHARK
350
351 // This is a guarantee instead of an assert because if vframe doesn't match
352 // we will unpack the wrong deoptimized frame and wind up in strange places
353 // where it will be very difficult to figure out what went wrong. Better
354 // to die an early death here than some very obscure death later when the
355 // trail is cold.
356 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
357 // in that it will fail to detect a problem when there is one. This needs
358 // more work in tiger timeframe.
359 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
360
361 int number_of_frames = array->frames();
362
363 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
364 // virtual activation, which is the reverse of the elements in the vframes array.
365 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
366 // +1 because we always have an interpreter return address for the final slot.
367 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
368 int popframe_extra_args = 0;
369 // Create an interpreter return address for the stub to use as its return
370 // address so the skeletal frames are perfectly walkable
371 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
372
373 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
374 // activation be put back on the expression stack of the caller for reexecution
375 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
376 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
377 }
378
379 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
380 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
381 // than simply use array->sender.pc(). This requires us to walk the current set of frames
382 //
383 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
384 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
385
386 // It's possible that the number of paramters at the call site is
387 // different than number of arguments in the callee when method
388 // handles are used. If the caller is interpreted get the real
389 // value so that the proper amount of space can be added to it's
390 // frame.
391 bool caller_was_method_handle = false;
392 if (deopt_sender.is_interpreted_frame()) {
393 methodHandle method = deopt_sender.interpreter_frame_method();
394 Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
395 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
396 // Method handle invokes may involve fairly arbitrary chains of
397 // calls so it's impossible to know how much actual space the
398 // caller has for locals.
399 caller_was_method_handle = true;
400 }
401 }
402
403 //
404 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
405 // frame_sizes/frame_pcs[1] next oldest frame (int)
406 // frame_sizes/frame_pcs[n] youngest frame (int)
407 //
408 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
409 // owns the space for the return address to it's caller). Confusing ain't it.
410 //
411 // The vframe array can address vframes with indices running from
412 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
413 // When we create the skeletal frames we need the oldest frame to be in the zero slot
414 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
415 // so things look a little strange in this loop.
416 //
417 int callee_parameters = 0;
418 int callee_locals = 0;
419 for (int index = 0; index < array->frames(); index++ ) {
420 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
421 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
422 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
423 int caller_parms = callee_parameters;
424 if ((index == array->frames() - 1) && caller_was_method_handle) {
425 caller_parms = 0;
426 }
427 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(caller_parms,
428 callee_parameters,
429 callee_locals,
430 index == 0,
431 index == array->frames() - 1,
432 popframe_extra_args);
433 // This pc doesn't have to be perfect just good enough to identify the frame
434 // as interpreted so the skeleton frame will be walkable
435 // The correct pc will be set when the skeleton frame is completely filled out
436 // The final pc we store in the loop is wrong and will be overwritten below
437 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
438
439 callee_parameters = array->element(index)->method()->size_of_parameters();
440 callee_locals = array->element(index)->method()->max_locals();
441 popframe_extra_args = 0;
442 }
443
444 // Compute whether the root vframe returns a float or double value.
445 BasicType return_type;
446 {
447 HandleMark hm;
448 methodHandle method(thread, array->element(0)->method());
449 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
450 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
451 }
452
453 // Compute information for handling adapters and adjusting the frame size of the caller.
454 int caller_adjustment = 0;
455
456 // Compute the amount the oldest interpreter frame will have to adjust
457 // its caller's stack by. If the caller is a compiled frame then
458 // we pretend that the callee has no parameters so that the
459 // extension counts for the full amount of locals and not just
460 // locals-parms. This is because without a c2i adapter the parm
461 // area as created by the compiled frame will not be usable by
462 // the interpreter. (Depending on the calling convention there
463 // may not even be enough space).
464
465 // QQQ I'd rather see this pushed down into last_frame_adjust
466 // and have it take the sender (aka caller).
467
468 if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
469 caller_adjustment = last_frame_adjust(0, callee_locals);
470 } else if (callee_locals > callee_parameters) {
471 // The caller frame may need extending to accommodate
472 // non-parameter locals of the first unpacked interpreted frame.
473 // Compute that adjustment.
474 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
475 }
476
477 // If the sender is deoptimized the we must retrieve the address of the handler
478 // since the frame will "magically" show the original pc before the deopt
479 // and we'd undo the deopt.
480
481 frame_pcs[0] = deopt_sender.raw_pc();
482
483 #ifndef SHARK
484 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
485 #endif // SHARK
486
487 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
488 caller_adjustment * BytesPerWord,
489 caller_was_method_handle ? 0 : callee_parameters,
490 number_of_frames,
491 frame_sizes,
492 frame_pcs,
493 return_type);
494 // On some platforms, we need a way to pass some platform dependent
495 // information to the unpacking code so the skeletal frames come out
496 // correct (initial fp value, unextended sp, ...)
497 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
498
499 if (array->frames() > 1) {
500 if (VerifyStack && TraceDeoptimization) {
501 ttyLocker ttyl;
502 tty->print_cr("Deoptimizing method containing inlining");
503 }
504 }
505
506 array->set_unroll_block(info);
507 return info;
508 }
509
510 // Called to cleanup deoptimization data structures in normal case
511 // after unpacking to stack and when stack overflow error occurs
512 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
513 vframeArray *array) {
514
515 // Get array if coming from exception
516 if (array == NULL) {
517 array = thread->vframe_array_head();
518 }
519 thread->set_vframe_array_head(NULL);
520
521 // Free the previous UnrollBlock
522 vframeArray* old_array = thread->vframe_array_last();
523 thread->set_vframe_array_last(array);
524
525 if (old_array != NULL) {
526 UnrollBlock* old_info = old_array->unroll_block();
527 old_array->set_unroll_block(NULL);
528 delete old_info;
529 delete old_array;
530 }
531
532 // Deallocate any resource creating in this routine and any ResourceObjs allocated
533 // inside the vframeArray (StackValueCollections)
534
535 delete thread->deopt_mark();
536 thread->set_deopt_mark(NULL);
537 thread->set_deopt_nmethod(NULL);
538
539
540 if (JvmtiExport::can_pop_frame()) {
541 #ifndef CC_INTERP
542 // Regardless of whether we entered this routine with the pending
543 // popframe condition bit set, we should always clear it now
544 thread->clear_popframe_condition();
545 #else
546 // C++ interpeter will clear has_pending_popframe when it enters
547 // with method_resume. For deopt_resume2 we clear it now.
548 if (thread->popframe_forcing_deopt_reexecution())
549 thread->clear_popframe_condition();
550 #endif /* CC_INTERP */
551 }
552
553 // unpack_frames() is called at the end of the deoptimization handler
554 // and (in C2) at the end of the uncommon trap handler. Note this fact
555 // so that an asynchronous stack walker can work again. This counter is
556 // incremented at the beginning of fetch_unroll_info() and (in C2) at
557 // the beginning of uncommon_trap().
558 thread->dec_in_deopt_handler();
559 }
560
561
562 // Return BasicType of value being returned
563 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
564
565 // We are already active int he special DeoptResourceMark any ResourceObj's we
566 // allocate will be freed at the end of the routine.
567
568 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
569 // but makes the entry a little slower. There is however a little dance we have to
570 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
571 ResetNoHandleMark rnhm; // No-op in release/product versions
572 HandleMark hm;
573
574 frame stub_frame = thread->last_frame();
575
576 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
577 // must point to the vframeArray for the unpack frame.
578 vframeArray* array = thread->vframe_array_head();
579
580 #ifndef PRODUCT
581 if (TraceDeoptimization) {
582 ttyLocker ttyl;
583 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
584 }
585 #endif
586 Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
587 stub_frame.pc(), stub_frame.sp(), exec_mode);
588
589 UnrollBlock* info = array->unroll_block();
590
591 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
592 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
593
594 BasicType bt = info->return_type();
595
596 // If we have an exception pending, claim that the return type is an oop
597 // so the deopt_blob does not overwrite the exception_oop.
598
599 if (exec_mode == Unpack_exception)
600 bt = T_OBJECT;
601
602 // Cleanup thread deopt data
603 cleanup_deopt_info(thread, array);
604
605 #ifndef PRODUCT
606 if (VerifyStack) {
607 ResourceMark res_mark;
608
609 thread->validate_frame_layout();
610
611 // Verify that the just-unpacked frames match the interpreter's
612 // notions of expression stack and locals
613 vframeArray* cur_array = thread->vframe_array_last();
614 RegisterMap rm(thread, false);
615 rm.set_include_argument_oops(false);
616 bool is_top_frame = true;
617 int callee_size_of_parameters = 0;
618 int callee_max_locals = 0;
619 for (int i = 0; i < cur_array->frames(); i++) {
620 vframeArrayElement* el = cur_array->element(i);
621 frame* iframe = el->iframe();
622 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
623
624 // Get the oop map for this bci
625 InterpreterOopMap mask;
626 int cur_invoke_parameter_size = 0;
627 bool try_next_mask = false;
628 int next_mask_expression_stack_size = -1;
629 int top_frame_expression_stack_adjustment = 0;
630 methodHandle mh(thread, iframe->interpreter_frame_method());
631 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
632 BytecodeStream str(mh);
633 str.set_start(iframe->interpreter_frame_bci());
634 int max_bci = mh->code_size();
635 // Get to the next bytecode if possible
636 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
637 // Check to see if we can grab the number of outgoing arguments
638 // at an uncommon trap for an invoke (where the compiler
639 // generates debug info before the invoke has executed)
640 Bytecodes::Code cur_code = str.next();
641 if (cur_code == Bytecodes::_invokevirtual ||
642 cur_code == Bytecodes::_invokespecial ||
643 cur_code == Bytecodes::_invokestatic ||
644 cur_code == Bytecodes::_invokeinterface ||
645 cur_code == Bytecodes::_invokedynamic) {
646 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
647 Symbol* signature = invoke.signature();
648 ArgumentSizeComputer asc(signature);
649 cur_invoke_parameter_size = asc.size();
650 if (invoke.has_receiver()) {
651 // Add in receiver
652 ++cur_invoke_parameter_size;
653 }
654 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
655 callee_size_of_parameters++;
656 }
657 }
658 if (str.bci() < max_bci) {
659 Bytecodes::Code bc = str.next();
660 if (bc >= 0) {
661 // The interpreter oop map generator reports results before
662 // the current bytecode has executed except in the case of
663 // calls. It seems to be hard to tell whether the compiler
664 // has emitted debug information matching the "state before"
665 // a given bytecode or the state after, so we try both
666 switch (cur_code) {
667 case Bytecodes::_invokevirtual:
668 case Bytecodes::_invokespecial:
669 case Bytecodes::_invokestatic:
670 case Bytecodes::_invokeinterface:
671 case Bytecodes::_invokedynamic:
672 case Bytecodes::_athrow:
673 break;
674 default: {
675 InterpreterOopMap next_mask;
676 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
677 next_mask_expression_stack_size = next_mask.expression_stack_size();
678 // Need to subtract off the size of the result type of
679 // the bytecode because this is not described in the
680 // debug info but returned to the interpreter in the TOS
681 // caching register
682 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
683 if (bytecode_result_type != T_ILLEGAL) {
684 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
685 }
686 assert(top_frame_expression_stack_adjustment >= 0, "");
687 try_next_mask = true;
688 break;
689 }
690 }
691 }
692 }
693
694 // Verify stack depth and oops in frame
695 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
696 if (!(
697 /* SPARC */
698 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
699 /* x86 */
700 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
701 (try_next_mask &&
702 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
703 top_frame_expression_stack_adjustment))) ||
704 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
705 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
706 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
707 )) {
708 ttyLocker ttyl;
709
710 // Print out some information that will help us debug the problem
711 tty->print_cr("Wrong number of expression stack elements during deoptimization");
712 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
713 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
714 iframe->interpreter_frame_expression_stack_size());
715 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
716 tty->print_cr(" try_next_mask = %d", try_next_mask);
717 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
718 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
719 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
720 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
721 tty->print_cr(" exec_mode = %d", exec_mode);
722 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
723 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
724 tty->print_cr(" Interpreted frames:");
725 for (int k = 0; k < cur_array->frames(); k++) {
726 vframeArrayElement* el = cur_array->element(k);
727 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
728 }
729 cur_array->print_on_2(tty);
730 guarantee(false, "wrong number of expression stack elements during deopt");
731 }
732 VerifyOopClosure verify;
733 iframe->oops_interpreted_do(&verify, NULL, &rm, false);
734 callee_size_of_parameters = mh->size_of_parameters();
735 callee_max_locals = mh->max_locals();
736 is_top_frame = false;
737 }
738 }
739 #endif /* !PRODUCT */
740
741
742 return bt;
743 JRT_END
744
745
746 int Deoptimization::deoptimize_dependents() {
747 Threads::deoptimized_wrt_marked_nmethods();
748 return 0;
749 }
750
751
752 #ifdef COMPILER2
753 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
754 Handle pending_exception(thread->pending_exception());
755 const char* exception_file = thread->exception_file();
756 int exception_line = thread->exception_line();
757 thread->clear_pending_exception();
758
759 for (int i = 0; i < objects->length(); i++) {
760 assert(objects->at(i)->is_object(), "invalid debug information");
761 ObjectValue* sv = (ObjectValue*) objects->at(i);
762
763 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
764 oop obj = NULL;
765
766 if (k->oop_is_instance()) {
767 InstanceKlass* ik = InstanceKlass::cast(k());
768 obj = ik->allocate_instance(CHECK_(false));
769 } else if (k->oop_is_typeArray()) {
770 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
771 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
772 int len = sv->field_size() / type2size[ak->element_type()];
773 obj = ak->allocate(len, CHECK_(false));
774 } else if (k->oop_is_objArray()) {
775 ObjArrayKlass* ak = ObjArrayKlass::cast(k());
776 obj = ak->allocate(sv->field_size(), CHECK_(false));
777 }
778
779 assert(obj != NULL, "allocation failed");
780 assert(sv->value().is_null(), "redundant reallocation");
781 sv->set_value(obj);
782 }
783
784 if (pending_exception.not_null()) {
785 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
786 }
787
788 return true;
789 }
790
791 // This assumes that the fields are stored in ObjectValue in the same order
792 // they are yielded by do_nonstatic_fields.
793 class FieldReassigner: public FieldClosure {
794 frame* _fr;
795 RegisterMap* _reg_map;
796 ObjectValue* _sv;
797 InstanceKlass* _ik;
798 oop _obj;
799
800 int _i;
801 public:
802 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
803 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
804
805 int i() const { return _i; }
806
807
808 void do_field(fieldDescriptor* fd) {
809 intptr_t val;
810 StackValue* value =
811 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
812 int offset = fd->offset();
813 switch (fd->field_type()) {
814 case T_OBJECT: case T_ARRAY:
815 assert(value->type() == T_OBJECT, "Agreement.");
816 _obj->obj_field_put(offset, value->get_obj()());
817 break;
818
819 case T_LONG: case T_DOUBLE: {
820 assert(value->type() == T_INT, "Agreement.");
821 StackValue* low =
822 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
823 #ifdef _LP64
824 jlong res = (jlong)low->get_int();
825 #else
826 #ifdef SPARC
827 // For SPARC we have to swap high and low words.
828 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
829 #else
830 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
831 #endif //SPARC
832 #endif
833 _obj->long_field_put(offset, res);
834 break;
835 }
836 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
837 case T_INT: case T_FLOAT: // 4 bytes.
838 assert(value->type() == T_INT, "Agreement.");
839 val = value->get_int();
840 _obj->int_field_put(offset, (jint)*((jint*)&val));
841 break;
842
843 case T_SHORT: case T_CHAR: // 2 bytes
844 assert(value->type() == T_INT, "Agreement.");
845 val = value->get_int();
846 _obj->short_field_put(offset, (jshort)*((jint*)&val));
847 break;
848
849 case T_BOOLEAN: case T_BYTE: // 1 byte
850 assert(value->type() == T_INT, "Agreement.");
851 val = value->get_int();
852 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
853 break;
854
855 default:
856 ShouldNotReachHere();
857 }
858 _i++;
859 }
860 };
861
862 // restore elements of an eliminated type array
863 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
864 int index = 0;
865 intptr_t val;
866
867 for (int i = 0; i < sv->field_size(); i++) {
868 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
869 switch(type) {
870 case T_LONG: case T_DOUBLE: {
871 assert(value->type() == T_INT, "Agreement.");
872 StackValue* low =
873 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
874 #ifdef _LP64
875 jlong res = (jlong)low->get_int();
876 #else
877 #ifdef SPARC
878 // For SPARC we have to swap high and low words.
879 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
880 #else
881 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
882 #endif //SPARC
883 #endif
884 obj->long_at_put(index, res);
885 break;
886 }
887
888 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
889 case T_INT: case T_FLOAT: // 4 bytes.
890 assert(value->type() == T_INT, "Agreement.");
891 val = value->get_int();
892 obj->int_at_put(index, (jint)*((jint*)&val));
893 break;
894
895 case T_SHORT: case T_CHAR: // 2 bytes
896 assert(value->type() == T_INT, "Agreement.");
897 val = value->get_int();
898 obj->short_at_put(index, (jshort)*((jint*)&val));
899 break;
900
901 case T_BOOLEAN: case T_BYTE: // 1 byte
902 assert(value->type() == T_INT, "Agreement.");
903 val = value->get_int();
904 obj->bool_at_put(index, (jboolean)*((jint*)&val));
905 break;
906
907 default:
908 ShouldNotReachHere();
909 }
910 index++;
911 }
912 }
913
914
915 // restore fields of an eliminated object array
916 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
917 for (int i = 0; i < sv->field_size(); i++) {
918 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
919 assert(value->type() == T_OBJECT, "object element expected");
920 obj->obj_at_put(i, value->get_obj()());
921 }
922 }
923
924
925 // restore fields of all eliminated objects and arrays
926 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
927 for (int i = 0; i < objects->length(); i++) {
928 ObjectValue* sv = (ObjectValue*) objects->at(i);
929 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
930 Handle obj = sv->value();
931 assert(obj.not_null(), "reallocation was missed");
932
933 if (k->oop_is_instance()) {
934 InstanceKlass* ik = InstanceKlass::cast(k());
935 FieldReassigner reassign(fr, reg_map, sv, obj());
936 ik->do_nonstatic_fields(&reassign);
937 } else if (k->oop_is_typeArray()) {
938 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
939 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
940 } else if (k->oop_is_objArray()) {
941 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
942 }
943 }
944 }
945
946
947 // relock objects for which synchronization was eliminated
948 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
949 for (int i = 0; i < monitors->length(); i++) {
950 MonitorInfo* mon_info = monitors->at(i);
951 if (mon_info->eliminated()) {
952 assert(mon_info->owner() != NULL, "reallocation was missed");
953 Handle obj = Handle(mon_info->owner());
954 markOop mark = obj->mark();
955 if (UseBiasedLocking && mark->has_bias_pattern()) {
956 // New allocated objects may have the mark set to anonymously biased.
957 // Also the deoptimized method may called methods with synchronization
958 // where the thread-local object is bias locked to the current thread.
959 assert(mark->is_biased_anonymously() ||
960 mark->biased_locker() == thread, "should be locked to current thread");
961 // Reset mark word to unbiased prototype.
962 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
963 obj->set_mark(unbiased_prototype);
964 }
965 BasicLock* lock = mon_info->lock();
966 ObjectSynchronizer::slow_enter(obj, lock, thread);
967 }
968 assert(mon_info->owner()->is_locked(), "object must be locked now");
969 }
970 }
971
972
973 #ifndef PRODUCT
974 // print information about reallocated objects
975 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
976 fieldDescriptor fd;
977
978 for (int i = 0; i < objects->length(); i++) {
979 ObjectValue* sv = (ObjectValue*) objects->at(i);
980 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
981 Handle obj = sv->value();
982
983 tty->print(" object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
984 k->print_value();
985 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
986 tty->cr();
987
988 if (Verbose) {
989 k->oop_print_on(obj(), tty);
990 }
991 }
992 }
993 #endif
994 #endif // COMPILER2
995
996 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
997 Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
998
999 #ifndef PRODUCT
1000 if (TraceDeoptimization) {
1001 ttyLocker ttyl;
1002 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
1003 fr.print_on(tty);
1004 tty->print_cr(" Virtual frames (innermost first):");
1005 for (int index = 0; index < chunk->length(); index++) {
1006 compiledVFrame* vf = chunk->at(index);
1007 tty->print(" %2d - ", index);
1008 vf->print_value();
1009 int bci = chunk->at(index)->raw_bci();
1010 const char* code_name;
1011 if (bci == SynchronizationEntryBCI) {
1012 code_name = "sync entry";
1013 } else {
1014 Bytecodes::Code code = vf->method()->code_at(bci);
1015 code_name = Bytecodes::name(code);
1016 }
1017 tty->print(" - %s", code_name);
1018 tty->print_cr(" @ bci %d ", bci);
1019 if (Verbose) {
1020 vf->print();
1021 tty->cr();
1022 }
1023 }
1024 }
1025 #endif
1026
1027 // Register map for next frame (used for stack crawl). We capture
1028 // the state of the deopt'ing frame's caller. Thus if we need to
1029 // stuff a C2I adapter we can properly fill in the callee-save
1030 // register locations.
1031 frame caller = fr.sender(reg_map);
1032 int frame_size = caller.sp() - fr.sp();
1033
1034 frame sender = caller;
1035
1036 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1037 // the vframeArray containing the unpacking information is allocated in the C heap.
1038 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1039 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1040
1041 // Compare the vframeArray to the collected vframes
1042 assert(array->structural_compare(thread, chunk), "just checking");
1043
1044 #ifndef PRODUCT
1045 if (TraceDeoptimization) {
1046 ttyLocker ttyl;
1047 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1048 }
1049 #endif // PRODUCT
1050
1051 return array;
1052 }
1053
1054
1055 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1056 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1057 for (int i = 0; i < monitors->length(); i++) {
1058 MonitorInfo* mon_info = monitors->at(i);
1059 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1060 objects_to_revoke->append(Handle(mon_info->owner()));
1061 }
1062 }
1063 }
1064
1065
1066 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1067 if (!UseBiasedLocking) {
1068 return;
1069 }
1070
1071 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1072
1073 // Unfortunately we don't have a RegisterMap available in most of
1074 // the places we want to call this routine so we need to walk the
1075 // stack again to update the register map.
1076 if (map == NULL || !map->update_map()) {
1077 StackFrameStream sfs(thread, true);
1078 bool found = false;
1079 while (!found && !sfs.is_done()) {
1080 frame* cur = sfs.current();
1081 sfs.next();
1082 found = cur->id() == fr.id();
1083 }
1084 assert(found, "frame to be deoptimized not found on target thread's stack");
1085 map = sfs.register_map();
1086 }
1087
1088 vframe* vf = vframe::new_vframe(&fr, map, thread);
1089 compiledVFrame* cvf = compiledVFrame::cast(vf);
1090 // Revoke monitors' biases in all scopes
1091 while (!cvf->is_top()) {
1092 collect_monitors(cvf, objects_to_revoke);
1093 cvf = compiledVFrame::cast(cvf->sender());
1094 }
1095 collect_monitors(cvf, objects_to_revoke);
1096
1097 if (SafepointSynchronize::is_at_safepoint()) {
1098 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1099 } else {
1100 BiasedLocking::revoke(objects_to_revoke);
1101 }
1102 }
1103
1104
1105 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1106 if (!UseBiasedLocking) {
1107 return;
1108 }
1109
1110 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1111 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1112 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1113 if (jt->has_last_Java_frame()) {
1114 StackFrameStream sfs(jt, true);
1115 while (!sfs.is_done()) {
1116 frame* cur = sfs.current();
1117 if (cb->contains(cur->pc())) {
1118 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1119 compiledVFrame* cvf = compiledVFrame::cast(vf);
1120 // Revoke monitors' biases in all scopes
1121 while (!cvf->is_top()) {
1122 collect_monitors(cvf, objects_to_revoke);
1123 cvf = compiledVFrame::cast(cvf->sender());
1124 }
1125 collect_monitors(cvf, objects_to_revoke);
1126 }
1127 sfs.next();
1128 }
1129 }
1130 }
1131 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1132 }
1133
1134
1135 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1136 assert(fr.can_be_deoptimized(), "checking frame type");
1137
1138 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1139
1140 // Patch the nmethod so that when execution returns to it we will
1141 // deopt the execution state and return to the interpreter.
1142 fr.deoptimize(thread);
1143 }
1144
1145 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1146 // Deoptimize only if the frame comes from compile code.
1147 // Do not deoptimize the frame which is already patched
1148 // during the execution of the loops below.
1149 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1150 return;
1151 }
1152 ResourceMark rm;
1153 DeoptimizationMarker dm;
1154 if (UseBiasedLocking) {
1155 revoke_biases_of_monitors(thread, fr, map);
1156 }
1157 deoptimize_single_frame(thread, fr);
1158
1159 }
1160
1161
1162 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1163 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1164 "can only deoptimize other thread at a safepoint");
1165 // Compute frame and register map based on thread and sp.
1166 RegisterMap reg_map(thread, UseBiasedLocking);
1167 frame fr = thread->last_frame();
1168 while (fr.id() != id) {
1169 fr = fr.sender(®_map);
1170 }
1171 deoptimize(thread, fr, ®_map);
1172 }
1173
1174
1175 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1176 if (thread == Thread::current()) {
1177 Deoptimization::deoptimize_frame_internal(thread, id);
1178 } else {
1179 VM_DeoptimizeFrame deopt(thread, id);
1180 VMThread::execute(&deopt);
1181 }
1182 }
1183
1184
1185 // JVMTI PopFrame support
1186 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1187 {
1188 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1189 }
1190 JRT_END
1191
1192
1193 #if defined(COMPILER2) || defined(SHARK)
1194 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1195 // in case of an unresolved klass entry, load the class.
1196 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1197 Klass* tk = constant_pool->klass_at(index, CHECK);
1198 return;
1199 }
1200
1201 if (!constant_pool->tag_at(index).is_symbol()) return;
1202
1203 Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1204 Symbol* symbol = constant_pool->symbol_at(index);
1205
1206 // class name?
1207 if (symbol->byte_at(0) != '(') {
1208 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1209 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1210 return;
1211 }
1212
1213 // then it must be a signature!
1214 ResourceMark rm(THREAD);
1215 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1216 if (ss.is_object()) {
1217 Symbol* class_name = ss.as_symbol(CHECK);
1218 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1219 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1220 }
1221 }
1222 }
1223
1224
1225 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1226 EXCEPTION_MARK;
1227 load_class_by_index(constant_pool, index, THREAD);
1228 if (HAS_PENDING_EXCEPTION) {
1229 // Exception happened during classloading. We ignore the exception here, since it
1230 // is going to be rethrown since the current activation is going to be deoptimized and
1231 // the interpreter will re-execute the bytecode.
1232 CLEAR_PENDING_EXCEPTION;
1233 // Class loading called java code which may have caused a stack
1234 // overflow. If the exception was thrown right before the return
1235 // to the runtime the stack is no longer guarded. Reguard the
1236 // stack otherwise if we return to the uncommon trap blob and the
1237 // stack bang causes a stack overflow we crash.
1238 assert(THREAD->is_Java_thread(), "only a java thread can be here");
1239 JavaThread* thread = (JavaThread*)THREAD;
1240 bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1241 if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1242 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1243 }
1244 }
1245
1246 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1247 HandleMark hm;
1248
1249 // uncommon_trap() is called at the beginning of the uncommon trap
1250 // handler. Note this fact before we start generating temporary frames
1251 // that can confuse an asynchronous stack walker. This counter is
1252 // decremented at the end of unpack_frames().
1253 thread->inc_in_deopt_handler();
1254
1255 // We need to update the map if we have biased locking.
1256 RegisterMap reg_map(thread, UseBiasedLocking);
1257 frame stub_frame = thread->last_frame();
1258 frame fr = stub_frame.sender(®_map);
1259 // Make sure the calling nmethod is not getting deoptimized and removed
1260 // before we are done with it.
1261 nmethodLocker nl(fr.pc());
1262
1263 // Log a message
1264 Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1265 trap_request, fr.pc());
1266
1267 {
1268 ResourceMark rm;
1269
1270 // Revoke biases of any monitors in the frame to ensure we can migrate them
1271 revoke_biases_of_monitors(thread, fr, ®_map);
1272
1273 DeoptReason reason = trap_request_reason(trap_request);
1274 DeoptAction action = trap_request_action(trap_request);
1275 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1276
1277 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1278 compiledVFrame* cvf = compiledVFrame::cast(vf);
1279
1280 nmethod* nm = cvf->code();
1281
1282 ScopeDesc* trap_scope = cvf->scope();
1283 methodHandle trap_method = trap_scope->method();
1284 int trap_bci = trap_scope->bci();
1285 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1286
1287 // Record this event in the histogram.
1288 gather_statistics(reason, action, trap_bc);
1289
1290 // Ensure that we can record deopt. history:
1291 bool create_if_missing = ProfileTraps;
1292
1293 MethodData* trap_mdo =
1294 get_method_data(thread, trap_method, create_if_missing);
1295
1296 // Log a message
1297 Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1298 trap_reason_name(reason), trap_action_name(action), fr.pc(),
1299 trap_method->name_and_sig_as_C_string(), trap_bci);
1300
1301 // Print a bunch of diagnostics, if requested.
1302 if (TraceDeoptimization || LogCompilation) {
1303 ResourceMark rm;
1304 ttyLocker ttyl;
1305 char buf[100];
1306 if (xtty != NULL) {
1307 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1308 os::current_thread_id(),
1309 format_trap_request(buf, sizeof(buf), trap_request));
1310 nm->log_identity(xtty);
1311 }
1312 Symbol* class_name = NULL;
1313 bool unresolved = false;
1314 if (unloaded_class_index >= 0) {
1315 constantPoolHandle constants (THREAD, trap_method->constants());
1316 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1317 class_name = constants->klass_name_at(unloaded_class_index);
1318 unresolved = true;
1319 if (xtty != NULL)
1320 xtty->print(" unresolved='1'");
1321 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1322 class_name = constants->symbol_at(unloaded_class_index);
1323 }
1324 if (xtty != NULL)
1325 xtty->name(class_name);
1326 }
1327 if (xtty != NULL && trap_mdo != NULL) {
1328 // Dump the relevant MDO state.
1329 // This is the deopt count for the current reason, any previous
1330 // reasons or recompiles seen at this point.
1331 int dcnt = trap_mdo->trap_count(reason);
1332 if (dcnt != 0)
1333 xtty->print(" count='%d'", dcnt);
1334 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1335 int dos = (pdata == NULL)? 0: pdata->trap_state();
1336 if (dos != 0) {
1337 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1338 if (trap_state_is_recompiled(dos)) {
1339 int recnt2 = trap_mdo->overflow_recompile_count();
1340 if (recnt2 != 0)
1341 xtty->print(" recompiles2='%d'", recnt2);
1342 }
1343 }
1344 }
1345 if (xtty != NULL) {
1346 xtty->stamp();
1347 xtty->end_head();
1348 }
1349 if (TraceDeoptimization) { // make noise on the tty
1350 tty->print("Uncommon trap occurred in");
1351 nm->method()->print_short_name(tty);
1352 tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1353 fr.pc(),
1354 os::current_thread_id(),
1355 trap_reason_name(reason),
1356 trap_action_name(action),
1357 unloaded_class_index);
1358 if (class_name != NULL) {
1359 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1360 class_name->print_symbol_on(tty);
1361 }
1362 tty->cr();
1363 }
1364 if (xtty != NULL) {
1365 // Log the precise location of the trap.
1366 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1367 xtty->begin_elem("jvms bci='%d'", sd->bci());
1368 xtty->method(sd->method());
1369 xtty->end_elem();
1370 if (sd->is_top()) break;
1371 }
1372 xtty->tail("uncommon_trap");
1373 }
1374 }
1375 // (End diagnostic printout.)
1376
1377 // Load class if necessary
1378 if (unloaded_class_index >= 0) {
1379 constantPoolHandle constants(THREAD, trap_method->constants());
1380 load_class_by_index(constants, unloaded_class_index);
1381 }
1382
1383 // Flush the nmethod if necessary and desirable.
1384 //
1385 // We need to avoid situations where we are re-flushing the nmethod
1386 // because of a hot deoptimization site. Repeated flushes at the same
1387 // point need to be detected by the compiler and avoided. If the compiler
1388 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1389 // module must take measures to avoid an infinite cycle of recompilation
1390 // and deoptimization. There are several such measures:
1391 //
1392 // 1. If a recompilation is ordered a second time at some site X
1393 // and for the same reason R, the action is adjusted to 'reinterpret',
1394 // to give the interpreter time to exercise the method more thoroughly.
1395 // If this happens, the method's overflow_recompile_count is incremented.
1396 //
1397 // 2. If the compiler fails to reduce the deoptimization rate, then
1398 // the method's overflow_recompile_count will begin to exceed the set
1399 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1400 // is adjusted to 'make_not_compilable', and the method is abandoned
1401 // to the interpreter. This is a performance hit for hot methods,
1402 // but is better than a disastrous infinite cycle of recompilations.
1403 // (Actually, only the method containing the site X is abandoned.)
1404 //
1405 // 3. In parallel with the previous measures, if the total number of
1406 // recompilations of a method exceeds the much larger set limit
1407 // PerMethodRecompilationCutoff, the method is abandoned.
1408 // This should only happen if the method is very large and has
1409 // many "lukewarm" deoptimizations. The code which enforces this
1410 // limit is elsewhere (class nmethod, class Method).
1411 //
1412 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1413 // to recompile at each bytecode independently of the per-BCI cutoff.
1414 //
1415 // The decision to update code is up to the compiler, and is encoded
1416 // in the Action_xxx code. If the compiler requests Action_none
1417 // no trap state is changed, no compiled code is changed, and the
1418 // computation suffers along in the interpreter.
1419 //
1420 // The other action codes specify various tactics for decompilation
1421 // and recompilation. Action_maybe_recompile is the loosest, and
1422 // allows the compiled code to stay around until enough traps are seen,
1423 // and until the compiler gets around to recompiling the trapping method.
1424 //
1425 // The other actions cause immediate removal of the present code.
1426
1427 bool update_trap_state = true;
1428 bool make_not_entrant = false;
1429 bool make_not_compilable = false;
1430 bool reprofile = false;
1431 switch (action) {
1432 case Action_none:
1433 // Keep the old code.
1434 update_trap_state = false;
1435 break;
1436 case Action_maybe_recompile:
1437 // Do not need to invalidate the present code, but we can
1438 // initiate another
1439 // Start compiler without (necessarily) invalidating the nmethod.
1440 // The system will tolerate the old code, but new code should be
1441 // generated when possible.
1442 break;
1443 case Action_reinterpret:
1444 // Go back into the interpreter for a while, and then consider
1445 // recompiling form scratch.
1446 make_not_entrant = true;
1447 // Reset invocation counter for outer most method.
1448 // This will allow the interpreter to exercise the bytecodes
1449 // for a while before recompiling.
1450 // By contrast, Action_make_not_entrant is immediate.
1451 //
1452 // Note that the compiler will track null_check, null_assert,
1453 // range_check, and class_check events and log them as if they
1454 // had been traps taken from compiled code. This will update
1455 // the MDO trap history so that the next compilation will
1456 // properly detect hot trap sites.
1457 reprofile = true;
1458 break;
1459 case Action_make_not_entrant:
1460 // Request immediate recompilation, and get rid of the old code.
1461 // Make them not entrant, so next time they are called they get
1462 // recompiled. Unloaded classes are loaded now so recompile before next
1463 // time they are called. Same for uninitialized. The interpreter will
1464 // link the missing class, if any.
1465 make_not_entrant = true;
1466 break;
1467 case Action_make_not_compilable:
1468 // Give up on compiling this method at all.
1469 make_not_entrant = true;
1470 make_not_compilable = true;
1471 break;
1472 default:
1473 ShouldNotReachHere();
1474 }
1475
1476 // Setting +ProfileTraps fixes the following, on all platforms:
1477 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1478 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1479 // recompile relies on a MethodData* to record heroic opt failures.
1480
1481 // Whether the interpreter is producing MDO data or not, we also need
1482 // to use the MDO to detect hot deoptimization points and control
1483 // aggressive optimization.
1484 bool inc_recompile_count = false;
1485 ProfileData* pdata = NULL;
1486 if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1487 assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1488 uint this_trap_count = 0;
1489 bool maybe_prior_trap = false;
1490 bool maybe_prior_recompile = false;
1491 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1492 //outputs:
1493 this_trap_count,
1494 maybe_prior_trap,
1495 maybe_prior_recompile);
1496 // Because the interpreter also counts null, div0, range, and class
1497 // checks, these traps from compiled code are double-counted.
1498 // This is harmless; it just means that the PerXTrapLimit values
1499 // are in effect a little smaller than they look.
1500
1501 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1502 if (per_bc_reason != Reason_none) {
1503 // Now take action based on the partially known per-BCI history.
1504 if (maybe_prior_trap
1505 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1506 // If there are too many traps at this BCI, force a recompile.
1507 // This will allow the compiler to see the limit overflow, and
1508 // take corrective action, if possible. The compiler generally
1509 // does not use the exact PerBytecodeTrapLimit value, but instead
1510 // changes its tactics if it sees any traps at all. This provides
1511 // a little hysteresis, delaying a recompile until a trap happens
1512 // several times.
1513 //
1514 // Actually, since there is only one bit of counter per BCI,
1515 // the possible per-BCI counts are {0,1,(per-method count)}.
1516 // This produces accurate results if in fact there is only
1517 // one hot trap site, but begins to get fuzzy if there are
1518 // many sites. For example, if there are ten sites each
1519 // trapping two or more times, they each get the blame for
1520 // all of their traps.
1521 make_not_entrant = true;
1522 }
1523
1524 // Detect repeated recompilation at the same BCI, and enforce a limit.
1525 if (make_not_entrant && maybe_prior_recompile) {
1526 // More than one recompile at this point.
1527 inc_recompile_count = maybe_prior_trap;
1528 }
1529 } else {
1530 // For reasons which are not recorded per-bytecode, we simply
1531 // force recompiles unconditionally.
1532 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1533 make_not_entrant = true;
1534 }
1535
1536 // Go back to the compiler if there are too many traps in this method.
1537 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1538 // If there are too many traps in this method, force a recompile.
1539 // This will allow the compiler to see the limit overflow, and
1540 // take corrective action, if possible.
1541 // (This condition is an unlikely backstop only, because the
1542 // PerBytecodeTrapLimit is more likely to take effect first,
1543 // if it is applicable.)
1544 make_not_entrant = true;
1545 }
1546
1547 // Here's more hysteresis: If there has been a recompile at
1548 // this trap point already, run the method in the interpreter
1549 // for a while to exercise it more thoroughly.
1550 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1551 reprofile = true;
1552 }
1553
1554 }
1555
1556 // Take requested actions on the method:
1557
1558 // Recompile
1559 if (make_not_entrant) {
1560 if (!nm->make_not_entrant()) {
1561 return; // the call did not change nmethod's state
1562 }
1563
1564 if (pdata != NULL) {
1565 // Record the recompilation event, if any.
1566 int tstate0 = pdata->trap_state();
1567 int tstate1 = trap_state_set_recompiled(tstate0, true);
1568 if (tstate1 != tstate0)
1569 pdata->set_trap_state(tstate1);
1570 }
1571 }
1572
1573 if (inc_recompile_count) {
1574 trap_mdo->inc_overflow_recompile_count();
1575 if ((uint)trap_mdo->overflow_recompile_count() >
1576 (uint)PerBytecodeRecompilationCutoff) {
1577 // Give up on the method containing the bad BCI.
1578 if (trap_method() == nm->method()) {
1579 make_not_compilable = true;
1580 } else {
1581 trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1582 // But give grace to the enclosing nm->method().
1583 }
1584 }
1585 }
1586
1587 // Reprofile
1588 if (reprofile) {
1589 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1590 }
1591
1592 // Give up compiling
1593 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1594 assert(make_not_entrant, "consistent");
1595 nm->method()->set_not_compilable(CompLevel_full_optimization);
1596 }
1597
1598 } // Free marked resources
1599
1600 }
1601 JRT_END
1602
1603 MethodData*
1604 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1605 bool create_if_missing) {
1606 Thread* THREAD = thread;
1607 MethodData* mdo = m()->method_data();
1608 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1609 // Build an MDO. Ignore errors like OutOfMemory;
1610 // that simply means we won't have an MDO to update.
1611 Method::build_interpreter_method_data(m, THREAD);
1612 if (HAS_PENDING_EXCEPTION) {
1613 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1614 CLEAR_PENDING_EXCEPTION;
1615 }
1616 mdo = m()->method_data();
1617 }
1618 return mdo;
1619 }
1620
1621 ProfileData*
1622 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1623 int trap_bci,
1624 Deoptimization::DeoptReason reason,
1625 //outputs:
1626 uint& ret_this_trap_count,
1627 bool& ret_maybe_prior_trap,
1628 bool& ret_maybe_prior_recompile) {
1629 uint prior_trap_count = trap_mdo->trap_count(reason);
1630 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1631
1632 // If the runtime cannot find a place to store trap history,
1633 // it is estimated based on the general condition of the method.
1634 // If the method has ever been recompiled, or has ever incurred
1635 // a trap with the present reason , then this BCI is assumed
1636 // (pessimistically) to be the culprit.
1637 bool maybe_prior_trap = (prior_trap_count != 0);
1638 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1639 ProfileData* pdata = NULL;
1640
1641
1642 // For reasons which are recorded per bytecode, we check per-BCI data.
1643 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1644 if (per_bc_reason != Reason_none) {
1645 // Find the profile data for this BCI. If there isn't one,
1646 // try to allocate one from the MDO's set of spares.
1647 // This will let us detect a repeated trap at this point.
1648 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1649
1650 if (pdata != NULL) {
1651 // Query the trap state of this profile datum.
1652 int tstate0 = pdata->trap_state();
1653 if (!trap_state_has_reason(tstate0, per_bc_reason))
1654 maybe_prior_trap = false;
1655 if (!trap_state_is_recompiled(tstate0))
1656 maybe_prior_recompile = false;
1657
1658 // Update the trap state of this profile datum.
1659 int tstate1 = tstate0;
1660 // Record the reason.
1661 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1662 // Store the updated state on the MDO, for next time.
1663 if (tstate1 != tstate0)
1664 pdata->set_trap_state(tstate1);
1665 } else {
1666 if (LogCompilation && xtty != NULL) {
1667 ttyLocker ttyl;
1668 // Missing MDP? Leave a small complaint in the log.
1669 xtty->elem("missing_mdp bci='%d'", trap_bci);
1670 }
1671 }
1672 }
1673
1674 // Return results:
1675 ret_this_trap_count = this_trap_count;
1676 ret_maybe_prior_trap = maybe_prior_trap;
1677 ret_maybe_prior_recompile = maybe_prior_recompile;
1678 return pdata;
1679 }
1680
1681 void
1682 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1683 ResourceMark rm;
1684 // Ignored outputs:
1685 uint ignore_this_trap_count;
1686 bool ignore_maybe_prior_trap;
1687 bool ignore_maybe_prior_recompile;
1688 query_update_method_data(trap_mdo, trap_bci,
1689 (DeoptReason)reason,
1690 ignore_this_trap_count,
1691 ignore_maybe_prior_trap,
1692 ignore_maybe_prior_recompile);
1693 }
1694
1695 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1696
1697 // Still in Java no safepoints
1698 {
1699 // This enters VM and may safepoint
1700 uncommon_trap_inner(thread, trap_request);
1701 }
1702 return fetch_unroll_info_helper(thread);
1703 }
1704
1705 // Local derived constants.
1706 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1707 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1708 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1709
1710 //---------------------------trap_state_reason---------------------------------
1711 Deoptimization::DeoptReason
1712 Deoptimization::trap_state_reason(int trap_state) {
1713 // This assert provides the link between the width of DataLayout::trap_bits
1714 // and the encoding of "recorded" reasons. It ensures there are enough
1715 // bits to store all needed reasons in the per-BCI MDO profile.
1716 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1717 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1718 trap_state -= recompile_bit;
1719 if (trap_state == DS_REASON_MASK) {
1720 return Reason_many;
1721 } else {
1722 assert((int)Reason_none == 0, "state=0 => Reason_none");
1723 return (DeoptReason)trap_state;
1724 }
1725 }
1726 //-------------------------trap_state_has_reason-------------------------------
1727 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1728 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1729 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1730 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1731 trap_state -= recompile_bit;
1732 if (trap_state == DS_REASON_MASK) {
1733 return -1; // true, unspecifically (bottom of state lattice)
1734 } else if (trap_state == reason) {
1735 return 1; // true, definitely
1736 } else if (trap_state == 0) {
1737 return 0; // false, definitely (top of state lattice)
1738 } else {
1739 return 0; // false, definitely
1740 }
1741 }
1742 //-------------------------trap_state_add_reason-------------------------------
1743 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1744 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1745 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1746 trap_state -= recompile_bit;
1747 if (trap_state == DS_REASON_MASK) {
1748 return trap_state + recompile_bit; // already at state lattice bottom
1749 } else if (trap_state == reason) {
1750 return trap_state + recompile_bit; // the condition is already true
1751 } else if (trap_state == 0) {
1752 return reason + recompile_bit; // no condition has yet been true
1753 } else {
1754 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1755 }
1756 }
1757 //-----------------------trap_state_is_recompiled------------------------------
1758 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1759 return (trap_state & DS_RECOMPILE_BIT) != 0;
1760 }
1761 //-----------------------trap_state_set_recompiled-----------------------------
1762 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1763 if (z) return trap_state | DS_RECOMPILE_BIT;
1764 else return trap_state & ~DS_RECOMPILE_BIT;
1765 }
1766 //---------------------------format_trap_state---------------------------------
1767 // This is used for debugging and diagnostics, including LogFile output.
1768 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1769 int trap_state) {
1770 DeoptReason reason = trap_state_reason(trap_state);
1771 bool recomp_flag = trap_state_is_recompiled(trap_state);
1772 // Re-encode the state from its decoded components.
1773 int decoded_state = 0;
1774 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1775 decoded_state = trap_state_add_reason(decoded_state, reason);
1776 if (recomp_flag)
1777 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1778 // If the state re-encodes properly, format it symbolically.
1779 // Because this routine is used for debugging and diagnostics,
1780 // be robust even if the state is a strange value.
1781 size_t len;
1782 if (decoded_state != trap_state) {
1783 // Random buggy state that doesn't decode??
1784 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1785 } else {
1786 len = jio_snprintf(buf, buflen, "%s%s",
1787 trap_reason_name(reason),
1788 recomp_flag ? " recompiled" : "");
1789 }
1790 if (len >= buflen)
1791 buf[buflen-1] = '\0';
1792 return buf;
1793 }
1794
1795
1796 //--------------------------------statics--------------------------------------
1797 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1798 = Deoptimization::Action_reinterpret;
1799 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1800 // Note: Keep this in sync. with enum DeoptReason.
1801 "none",
1802 "null_check",
1803 "null_assert",
1804 "range_check",
1805 "class_check",
1806 "array_check",
1807 "intrinsic",
1808 "bimorphic",
1809 "unloaded",
1810 "uninitialized",
1811 "unreached",
1812 "unhandled",
1813 "constraint",
1814 "div0_check",
1815 "age",
1816 "predicate",
1817 "loop_limit_check"
1818 };
1819 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1820 // Note: Keep this in sync. with enum DeoptAction.
1821 "none",
1822 "maybe_recompile",
1823 "reinterpret",
1824 "make_not_entrant",
1825 "make_not_compilable"
1826 };
1827
1828 const char* Deoptimization::trap_reason_name(int reason) {
1829 if (reason == Reason_many) return "many";
1830 if ((uint)reason < Reason_LIMIT)
1831 return _trap_reason_name[reason];
1832 static char buf[20];
1833 sprintf(buf, "reason%d", reason);
1834 return buf;
1835 }
1836 const char* Deoptimization::trap_action_name(int action) {
1837 if ((uint)action < Action_LIMIT)
1838 return _trap_action_name[action];
1839 static char buf[20];
1840 sprintf(buf, "action%d", action);
1841 return buf;
1842 }
1843
1844 // This is used for debugging and diagnostics, including LogFile output.
1845 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1846 int trap_request) {
1847 jint unloaded_class_index = trap_request_index(trap_request);
1848 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1849 const char* action = trap_action_name(trap_request_action(trap_request));
1850 size_t len;
1851 if (unloaded_class_index < 0) {
1852 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1853 reason, action);
1854 } else {
1855 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1856 reason, action, unloaded_class_index);
1857 }
1858 if (len >= buflen)
1859 buf[buflen-1] = '\0';
1860 return buf;
1861 }
1862
1863 juint Deoptimization::_deoptimization_hist
1864 [Deoptimization::Reason_LIMIT]
1865 [1 + Deoptimization::Action_LIMIT]
1866 [Deoptimization::BC_CASE_LIMIT]
1867 = {0};
1868
1869 enum {
1870 LSB_BITS = 8,
1871 LSB_MASK = right_n_bits(LSB_BITS)
1872 };
1873
1874 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1875 Bytecodes::Code bc) {
1876 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1877 assert(action >= 0 && action < Action_LIMIT, "oob");
1878 _deoptimization_hist[Reason_none][0][0] += 1; // total
1879 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1880 juint* cases = _deoptimization_hist[reason][1+action];
1881 juint* bc_counter_addr = NULL;
1882 juint bc_counter = 0;
1883 // Look for an unused counter, or an exact match to this BC.
1884 if (bc != Bytecodes::_illegal) {
1885 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1886 juint* counter_addr = &cases[bc_case];
1887 juint counter = *counter_addr;
1888 if ((counter == 0 && bc_counter_addr == NULL)
1889 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1890 // this counter is either free or is already devoted to this BC
1891 bc_counter_addr = counter_addr;
1892 bc_counter = counter | bc;
1893 }
1894 }
1895 }
1896 if (bc_counter_addr == NULL) {
1897 // Overflow, or no given bytecode.
1898 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1899 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1900 }
1901 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1902 }
1903
1904 jint Deoptimization::total_deoptimization_count() {
1905 return _deoptimization_hist[Reason_none][0][0];
1906 }
1907
1908 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1909 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1910 return _deoptimization_hist[reason][0][0];
1911 }
1912
1913 void Deoptimization::print_statistics() {
1914 juint total = total_deoptimization_count();
1915 juint account = total;
1916 if (total != 0) {
1917 ttyLocker ttyl;
1918 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1919 tty->print_cr("Deoptimization traps recorded:");
1920 #define PRINT_STAT_LINE(name, r) \
1921 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1922 PRINT_STAT_LINE("total", total);
1923 // For each non-zero entry in the histogram, print the reason,
1924 // the action, and (if specifically known) the type of bytecode.
1925 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1926 for (int action = 0; action < Action_LIMIT; action++) {
1927 juint* cases = _deoptimization_hist[reason][1+action];
1928 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1929 juint counter = cases[bc_case];
1930 if (counter != 0) {
1931 char name[1*K];
1932 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1933 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1934 bc = Bytecodes::_illegal;
1935 sprintf(name, "%s/%s/%s",
1936 trap_reason_name(reason),
1937 trap_action_name(action),
1938 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1939 juint r = counter >> LSB_BITS;
1940 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1941 account -= r;
1942 }
1943 }
1944 }
1945 }
1946 if (account != 0) {
1947 PRINT_STAT_LINE("unaccounted", account);
1948 }
1949 #undef PRINT_STAT_LINE
1950 if (xtty != NULL) xtty->tail("statistics");
1951 }
1952 }
1953 #else // COMPILER2 || SHARK
1954
1955
1956 // Stubs for C1 only system.
1957 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1958 return false;
1959 }
1960
1961 const char* Deoptimization::trap_reason_name(int reason) {
1962 return "unknown";
1963 }
1964
1965 void Deoptimization::print_statistics() {
1966 // no output
1967 }
1968
1969 void
1970 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1971 // no udpate
1972 }
1973
1974 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1975 return 0;
1976 }
1977
1978 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1979 Bytecodes::Code bc) {
1980 // no update
1981 }
1982
1983 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1984 int trap_state) {
1985 jio_snprintf(buf, buflen, "#%d", trap_state);
1986 return buf;
1987 }
1988
1989 #endif // COMPILER2 || SHARK