Wed, 04 May 2011 22:31:18 -0700
7042052: Xcomp crash with PopSynchronousTest
Reviewed-by: kvn, iveresov
1 /*
2 * Copyright (c) 1997, 2011, 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.
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23 */
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/methodOop.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef 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
85 # include "adfiles/ad_ppc.hpp"
86 #endif
87 #endif
89 bool DeoptimizationMarker::_is_active = false;
91 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
92 int caller_adjustment,
93 int number_of_frames,
94 intptr_t* frame_sizes,
95 address* frame_pcs,
96 BasicType return_type) {
97 _size_of_deoptimized_frame = size_of_deoptimized_frame;
98 _caller_adjustment = caller_adjustment;
99 _number_of_frames = number_of_frames;
100 _frame_sizes = frame_sizes;
101 _frame_pcs = frame_pcs;
102 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
103 _return_type = return_type;
104 _initial_fp = 0;
105 // PD (x86 only)
106 _counter_temp = 0;
107 _unpack_kind = 0;
108 _sender_sp_temp = 0;
110 _total_frame_sizes = size_of_frames();
111 }
114 Deoptimization::UnrollBlock::~UnrollBlock() {
115 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
116 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
117 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
118 }
121 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
122 assert(register_number < RegisterMap::reg_count, "checking register number");
123 return &_register_block[register_number * 2];
124 }
128 int Deoptimization::UnrollBlock::size_of_frames() const {
129 // Acount first for the adjustment of the initial frame
130 int result = _caller_adjustment;
131 for (int index = 0; index < number_of_frames(); index++) {
132 result += frame_sizes()[index];
133 }
134 return result;
135 }
138 void Deoptimization::UnrollBlock::print() {
139 ttyLocker ttyl;
140 tty->print_cr("UnrollBlock");
141 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
142 tty->print( " frame_sizes: ");
143 for (int index = 0; index < number_of_frames(); index++) {
144 tty->print("%d ", frame_sizes()[index]);
145 }
146 tty->cr();
147 }
150 // In order to make fetch_unroll_info work properly with escape
151 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
152 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
153 // of previously eliminated objects occurs in realloc_objects, which is
154 // called from the method fetch_unroll_info_helper below.
155 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
156 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
157 // but makes the entry a little slower. There is however a little dance we have to
158 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
160 // fetch_unroll_info() is called at the beginning of the deoptimization
161 // handler. Note this fact before we start generating temporary frames
162 // that can confuse an asynchronous stack walker. This counter is
163 // decremented at the end of unpack_frames().
164 thread->inc_in_deopt_handler();
166 return fetch_unroll_info_helper(thread);
167 JRT_END
170 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
171 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
173 // Note: there is a safepoint safety issue here. No matter whether we enter
174 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
175 // the vframeArray is created.
176 //
178 // Allocate our special deoptimization ResourceMark
179 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
180 assert(thread->deopt_mark() == NULL, "Pending deopt!");
181 thread->set_deopt_mark(dmark);
183 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
184 RegisterMap map(thread, true);
185 RegisterMap dummy_map(thread, false);
186 // Now get the deoptee with a valid map
187 frame deoptee = stub_frame.sender(&map);
188 // Set the deoptee nmethod
189 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
190 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
192 if (VerifyStack) {
193 thread->validate_frame_layout();
194 }
196 // Create a growable array of VFrames where each VFrame represents an inlined
197 // Java frame. This storage is allocated with the usual system arena.
198 assert(deoptee.is_compiled_frame(), "Wrong frame type");
199 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
200 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
201 while (!vf->is_top()) {
202 assert(vf->is_compiled_frame(), "Wrong frame type");
203 chunk->push(compiledVFrame::cast(vf));
204 vf = vf->sender();
205 }
206 assert(vf->is_compiled_frame(), "Wrong frame type");
207 chunk->push(compiledVFrame::cast(vf));
209 #ifdef COMPILER2
210 // Reallocate the non-escaping objects and restore their fields. Then
211 // relock objects if synchronization on them was eliminated.
212 if (DoEscapeAnalysis) {
213 if (EliminateAllocations) {
214 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
215 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
217 // The flag return_oop() indicates call sites which return oop
218 // in compiled code. Such sites include java method calls,
219 // runtime calls (for example, used to allocate new objects/arrays
220 // on slow code path) and any other calls generated in compiled code.
221 // It is not guaranteed that we can get such information here only
222 // by analyzing bytecode in deoptimized frames. This is why this flag
223 // is set during method compilation (see Compile::Process_OopMap_Node()).
224 bool save_oop_result = chunk->at(0)->scope()->return_oop();
225 Handle return_value;
226 if (save_oop_result) {
227 // Reallocation may trigger GC. If deoptimization happened on return from
228 // call which returns oop we need to save it since it is not in oopmap.
229 oop result = deoptee.saved_oop_result(&map);
230 assert(result == NULL || result->is_oop(), "must be oop");
231 return_value = Handle(thread, result);
232 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
233 if (TraceDeoptimization) {
234 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
235 }
236 }
237 bool reallocated = false;
238 if (objects != NULL) {
239 JRT_BLOCK
240 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
241 JRT_END
242 }
243 if (reallocated) {
244 reassign_fields(&deoptee, &map, objects);
245 #ifndef PRODUCT
246 if (TraceDeoptimization) {
247 ttyLocker ttyl;
248 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
249 print_objects(objects);
250 }
251 #endif
252 }
253 if (save_oop_result) {
254 // Restore result.
255 deoptee.set_saved_oop_result(&map, return_value());
256 }
257 }
258 if (EliminateLocks) {
259 #ifndef PRODUCT
260 bool first = true;
261 #endif
262 for (int i = 0; i < chunk->length(); i++) {
263 compiledVFrame* cvf = chunk->at(i);
264 assert (cvf->scope() != NULL,"expect only compiled java frames");
265 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
266 if (monitors->is_nonempty()) {
267 relock_objects(monitors, thread);
268 #ifndef PRODUCT
269 if (TraceDeoptimization) {
270 ttyLocker ttyl;
271 for (int j = 0; j < monitors->length(); j++) {
272 MonitorInfo* mi = monitors->at(j);
273 if (mi->eliminated()) {
274 if (first) {
275 first = false;
276 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
277 }
278 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
279 }
280 }
281 }
282 #endif
283 }
284 }
285 }
286 }
287 #endif // COMPILER2
288 // Ensure that no safepoint is taken after pointers have been stored
289 // in fields of rematerialized objects. If a safepoint occurs from here on
290 // out the java state residing in the vframeArray will be missed.
291 No_Safepoint_Verifier no_safepoint;
293 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
295 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
296 thread->set_vframe_array_head(array);
298 // Now that the vframeArray has been created if we have any deferred local writes
299 // added by jvmti then we can free up that structure as the data is now in the
300 // vframeArray
302 if (thread->deferred_locals() != NULL) {
303 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
304 int i = 0;
305 do {
306 // Because of inlining we could have multiple vframes for a single frame
307 // and several of the vframes could have deferred writes. Find them all.
308 if (list->at(i)->id() == array->original().id()) {
309 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
310 list->remove_at(i);
311 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
312 delete dlv;
313 } else {
314 i++;
315 }
316 } while ( i < list->length() );
317 if (list->length() == 0) {
318 thread->set_deferred_locals(NULL);
319 // free the list and elements back to C heap.
320 delete list;
321 }
323 }
325 #ifndef SHARK
326 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
327 CodeBlob* cb = stub_frame.cb();
328 // Verify we have the right vframeArray
329 assert(cb->frame_size() >= 0, "Unexpected frame size");
330 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
332 // If the deopt call site is a MethodHandle invoke call site we have
333 // to adjust the unpack_sp.
334 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
335 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
336 unpack_sp = deoptee.unextended_sp();
338 #ifdef ASSERT
339 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
340 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
341 #endif
342 #else
343 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
344 #endif // !SHARK
346 // This is a guarantee instead of an assert because if vframe doesn't match
347 // we will unpack the wrong deoptimized frame and wind up in strange places
348 // where it will be very difficult to figure out what went wrong. Better
349 // to die an early death here than some very obscure death later when the
350 // trail is cold.
351 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
352 // in that it will fail to detect a problem when there is one. This needs
353 // more work in tiger timeframe.
354 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
356 int number_of_frames = array->frames();
358 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
359 // virtual activation, which is the reverse of the elements in the vframes array.
360 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
361 // +1 because we always have an interpreter return address for the final slot.
362 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
363 int callee_parameters = 0;
364 int callee_locals = 0;
365 int popframe_extra_args = 0;
366 // Create an interpreter return address for the stub to use as its return
367 // address so the skeletal frames are perfectly walkable
368 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
370 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
371 // activation be put back on the expression stack of the caller for reexecution
372 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
373 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
374 }
376 //
377 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
378 // frame_sizes/frame_pcs[1] next oldest frame (int)
379 // frame_sizes/frame_pcs[n] youngest frame (int)
380 //
381 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
382 // owns the space for the return address to it's caller). Confusing ain't it.
383 //
384 // The vframe array can address vframes with indices running from
385 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
386 // When we create the skeletal frames we need the oldest frame to be in the zero slot
387 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
388 // so things look a little strange in this loop.
389 //
390 for (int index = 0; index < array->frames(); index++ ) {
391 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
392 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
393 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
394 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
395 callee_locals,
396 index == 0,
397 popframe_extra_args);
398 // This pc doesn't have to be perfect just good enough to identify the frame
399 // as interpreted so the skeleton frame will be walkable
400 // The correct pc will be set when the skeleton frame is completely filled out
401 // The final pc we store in the loop is wrong and will be overwritten below
402 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
404 callee_parameters = array->element(index)->method()->size_of_parameters();
405 callee_locals = array->element(index)->method()->max_locals();
406 popframe_extra_args = 0;
407 }
409 // Compute whether the root vframe returns a float or double value.
410 BasicType return_type;
411 {
412 HandleMark hm;
413 methodHandle method(thread, array->element(0)->method());
414 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
415 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
416 }
418 // Compute information for handling adapters and adjusting the frame size of the caller.
419 int caller_adjustment = 0;
421 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
422 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
423 // than simply use array->sender.pc(). This requires us to walk the current set of frames
424 //
425 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
426 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
428 // It's possible that the number of paramters at the call site is
429 // different than number of arguments in the callee when method
430 // handles are used. If the caller is interpreted get the real
431 // value so that the proper amount of space can be added to it's
432 // frame.
433 int sender_callee_parameters = callee_parameters;
434 if (deopt_sender.is_interpreted_frame()) {
435 methodHandle method = deopt_sender.interpreter_frame_method();
436 Bytecode_invoke cur = Bytecode_invoke_check(method,
437 deopt_sender.interpreter_frame_bci());
438 Symbol* signature = method->constants()->signature_ref_at(cur.index());
439 ArgumentSizeComputer asc(signature);
440 sender_callee_parameters = asc.size() + (cur.has_receiver() ? 1 : 0);
441 }
443 // Compute the amount the oldest interpreter frame will have to adjust
444 // its caller's stack by. If the caller is a compiled frame then
445 // we pretend that the callee has no parameters so that the
446 // extension counts for the full amount of locals and not just
447 // locals-parms. This is because without a c2i adapter the parm
448 // area as created by the compiled frame will not be usable by
449 // the interpreter. (Depending on the calling convention there
450 // may not even be enough space).
452 // QQQ I'd rather see this pushed down into last_frame_adjust
453 // and have it take the sender (aka caller).
455 if (deopt_sender.is_compiled_frame()) {
456 caller_adjustment = last_frame_adjust(0, callee_locals);
457 } else if (callee_locals > sender_callee_parameters) {
458 // The caller frame may need extending to accommodate
459 // non-parameter locals of the first unpacked interpreted frame.
460 // Compute that adjustment.
461 caller_adjustment = last_frame_adjust(sender_callee_parameters, callee_locals);
462 }
464 // If the sender is deoptimized the we must retrieve the address of the handler
465 // since the frame will "magically" show the original pc before the deopt
466 // and we'd undo the deopt.
468 frame_pcs[0] = deopt_sender.raw_pc();
470 #ifndef SHARK
471 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
472 #endif // SHARK
474 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
475 caller_adjustment * BytesPerWord,
476 number_of_frames,
477 frame_sizes,
478 frame_pcs,
479 return_type);
480 // On some platforms, we need a way to pass fp to the unpacking code
481 // so the skeletal frames come out correct.
482 info->set_initial_fp((intptr_t) array->sender().fp());
484 if (array->frames() > 1) {
485 if (VerifyStack && TraceDeoptimization) {
486 tty->print_cr("Deoptimizing method containing inlining");
487 }
488 }
490 array->set_unroll_block(info);
491 return info;
492 }
494 // Called to cleanup deoptimization data structures in normal case
495 // after unpacking to stack and when stack overflow error occurs
496 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
497 vframeArray *array) {
499 // Get array if coming from exception
500 if (array == NULL) {
501 array = thread->vframe_array_head();
502 }
503 thread->set_vframe_array_head(NULL);
505 // Free the previous UnrollBlock
506 vframeArray* old_array = thread->vframe_array_last();
507 thread->set_vframe_array_last(array);
509 if (old_array != NULL) {
510 UnrollBlock* old_info = old_array->unroll_block();
511 old_array->set_unroll_block(NULL);
512 delete old_info;
513 delete old_array;
514 }
516 // Deallocate any resource creating in this routine and any ResourceObjs allocated
517 // inside the vframeArray (StackValueCollections)
519 delete thread->deopt_mark();
520 thread->set_deopt_mark(NULL);
521 thread->set_deopt_nmethod(NULL);
524 if (JvmtiExport::can_pop_frame()) {
525 #ifndef CC_INTERP
526 // Regardless of whether we entered this routine with the pending
527 // popframe condition bit set, we should always clear it now
528 thread->clear_popframe_condition();
529 #else
530 // C++ interpeter will clear has_pending_popframe when it enters
531 // with method_resume. For deopt_resume2 we clear it now.
532 if (thread->popframe_forcing_deopt_reexecution())
533 thread->clear_popframe_condition();
534 #endif /* CC_INTERP */
535 }
537 // unpack_frames() is called at the end of the deoptimization handler
538 // and (in C2) at the end of the uncommon trap handler. Note this fact
539 // so that an asynchronous stack walker can work again. This counter is
540 // incremented at the beginning of fetch_unroll_info() and (in C2) at
541 // the beginning of uncommon_trap().
542 thread->dec_in_deopt_handler();
543 }
546 // Return BasicType of value being returned
547 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
549 // We are already active int he special DeoptResourceMark any ResourceObj's we
550 // allocate will be freed at the end of the routine.
552 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
553 // but makes the entry a little slower. There is however a little dance we have to
554 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
555 ResetNoHandleMark rnhm; // No-op in release/product versions
556 HandleMark hm;
558 frame stub_frame = thread->last_frame();
560 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
561 // must point to the vframeArray for the unpack frame.
562 vframeArray* array = thread->vframe_array_head();
564 #ifndef PRODUCT
565 if (TraceDeoptimization) {
566 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
567 }
568 #endif
570 UnrollBlock* info = array->unroll_block();
572 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
573 array->unpack_to_stack(stub_frame, exec_mode);
575 BasicType bt = info->return_type();
577 // If we have an exception pending, claim that the return type is an oop
578 // so the deopt_blob does not overwrite the exception_oop.
580 if (exec_mode == Unpack_exception)
581 bt = T_OBJECT;
583 // Cleanup thread deopt data
584 cleanup_deopt_info(thread, array);
586 #ifndef PRODUCT
587 if (VerifyStack) {
588 ResourceMark res_mark;
590 thread->validate_frame_layout();
592 // Verify that the just-unpacked frames match the interpreter's
593 // notions of expression stack and locals
594 vframeArray* cur_array = thread->vframe_array_last();
595 RegisterMap rm(thread, false);
596 rm.set_include_argument_oops(false);
597 bool is_top_frame = true;
598 int callee_size_of_parameters = 0;
599 int callee_max_locals = 0;
600 for (int i = 0; i < cur_array->frames(); i++) {
601 vframeArrayElement* el = cur_array->element(i);
602 frame* iframe = el->iframe();
603 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
605 // Get the oop map for this bci
606 InterpreterOopMap mask;
607 int cur_invoke_parameter_size = 0;
608 bool try_next_mask = false;
609 int next_mask_expression_stack_size = -1;
610 int top_frame_expression_stack_adjustment = 0;
611 methodHandle mh(thread, iframe->interpreter_frame_method());
612 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
613 BytecodeStream str(mh);
614 str.set_start(iframe->interpreter_frame_bci());
615 int max_bci = mh->code_size();
616 // Get to the next bytecode if possible
617 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
618 // Check to see if we can grab the number of outgoing arguments
619 // at an uncommon trap for an invoke (where the compiler
620 // generates debug info before the invoke has executed)
621 Bytecodes::Code cur_code = str.next();
622 if (cur_code == Bytecodes::_invokevirtual ||
623 cur_code == Bytecodes::_invokespecial ||
624 cur_code == Bytecodes::_invokestatic ||
625 cur_code == Bytecodes::_invokeinterface) {
626 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
627 Symbol* signature = invoke.signature();
628 ArgumentSizeComputer asc(signature);
629 cur_invoke_parameter_size = asc.size();
630 if (cur_code != Bytecodes::_invokestatic) {
631 // Add in receiver
632 ++cur_invoke_parameter_size;
633 }
634 }
635 if (str.bci() < max_bci) {
636 Bytecodes::Code bc = str.next();
637 if (bc >= 0) {
638 // The interpreter oop map generator reports results before
639 // the current bytecode has executed except in the case of
640 // calls. It seems to be hard to tell whether the compiler
641 // has emitted debug information matching the "state before"
642 // a given bytecode or the state after, so we try both
643 switch (cur_code) {
644 case Bytecodes::_invokevirtual:
645 case Bytecodes::_invokespecial:
646 case Bytecodes::_invokestatic:
647 case Bytecodes::_invokeinterface:
648 case Bytecodes::_athrow:
649 break;
650 default: {
651 InterpreterOopMap next_mask;
652 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
653 next_mask_expression_stack_size = next_mask.expression_stack_size();
654 // Need to subtract off the size of the result type of
655 // the bytecode because this is not described in the
656 // debug info but returned to the interpreter in the TOS
657 // caching register
658 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
659 if (bytecode_result_type != T_ILLEGAL) {
660 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
661 }
662 assert(top_frame_expression_stack_adjustment >= 0, "");
663 try_next_mask = true;
664 break;
665 }
666 }
667 }
668 }
670 // Verify stack depth and oops in frame
671 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
672 if (!(
673 /* SPARC */
674 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
675 /* x86 */
676 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
677 (try_next_mask &&
678 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
679 top_frame_expression_stack_adjustment))) ||
680 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
681 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
682 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
683 )) {
684 ttyLocker ttyl;
686 // Print out some information that will help us debug the problem
687 tty->print_cr("Wrong number of expression stack elements during deoptimization");
688 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
689 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
690 iframe->interpreter_frame_expression_stack_size());
691 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
692 tty->print_cr(" try_next_mask = %d", try_next_mask);
693 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
694 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
695 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
696 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
697 tty->print_cr(" exec_mode = %d", exec_mode);
698 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
699 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
700 tty->print_cr(" Interpreted frames:");
701 for (int k = 0; k < cur_array->frames(); k++) {
702 vframeArrayElement* el = cur_array->element(k);
703 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
704 }
705 cur_array->print_on_2(tty);
706 guarantee(false, "wrong number of expression stack elements during deopt");
707 }
708 VerifyOopClosure verify;
709 iframe->oops_interpreted_do(&verify, &rm, false);
710 callee_size_of_parameters = mh->size_of_parameters();
711 callee_max_locals = mh->max_locals();
712 is_top_frame = false;
713 }
714 }
715 #endif /* !PRODUCT */
718 return bt;
719 JRT_END
722 int Deoptimization::deoptimize_dependents() {
723 Threads::deoptimized_wrt_marked_nmethods();
724 return 0;
725 }
728 #ifdef COMPILER2
729 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
730 Handle pending_exception(thread->pending_exception());
731 const char* exception_file = thread->exception_file();
732 int exception_line = thread->exception_line();
733 thread->clear_pending_exception();
735 for (int i = 0; i < objects->length(); i++) {
736 assert(objects->at(i)->is_object(), "invalid debug information");
737 ObjectValue* sv = (ObjectValue*) objects->at(i);
739 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
740 oop obj = NULL;
742 if (k->oop_is_instance()) {
743 instanceKlass* ik = instanceKlass::cast(k());
744 obj = ik->allocate_instance(CHECK_(false));
745 } else if (k->oop_is_typeArray()) {
746 typeArrayKlass* ak = typeArrayKlass::cast(k());
747 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
748 int len = sv->field_size() / type2size[ak->element_type()];
749 obj = ak->allocate(len, CHECK_(false));
750 } else if (k->oop_is_objArray()) {
751 objArrayKlass* ak = objArrayKlass::cast(k());
752 obj = ak->allocate(sv->field_size(), CHECK_(false));
753 }
755 assert(obj != NULL, "allocation failed");
756 assert(sv->value().is_null(), "redundant reallocation");
757 sv->set_value(obj);
758 }
760 if (pending_exception.not_null()) {
761 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
762 }
764 return true;
765 }
767 // This assumes that the fields are stored in ObjectValue in the same order
768 // they are yielded by do_nonstatic_fields.
769 class FieldReassigner: public FieldClosure {
770 frame* _fr;
771 RegisterMap* _reg_map;
772 ObjectValue* _sv;
773 instanceKlass* _ik;
774 oop _obj;
776 int _i;
777 public:
778 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
779 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
781 int i() const { return _i; }
784 void do_field(fieldDescriptor* fd) {
785 intptr_t val;
786 StackValue* value =
787 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
788 int offset = fd->offset();
789 switch (fd->field_type()) {
790 case T_OBJECT: case T_ARRAY:
791 assert(value->type() == T_OBJECT, "Agreement.");
792 _obj->obj_field_put(offset, value->get_obj()());
793 break;
795 case T_LONG: case T_DOUBLE: {
796 assert(value->type() == T_INT, "Agreement.");
797 StackValue* low =
798 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
799 #ifdef _LP64
800 jlong res = (jlong)low->get_int();
801 #else
802 #ifdef SPARC
803 // For SPARC we have to swap high and low words.
804 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
805 #else
806 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
807 #endif //SPARC
808 #endif
809 _obj->long_field_put(offset, res);
810 break;
811 }
812 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
813 case T_INT: case T_FLOAT: // 4 bytes.
814 assert(value->type() == T_INT, "Agreement.");
815 val = value->get_int();
816 _obj->int_field_put(offset, (jint)*((jint*)&val));
817 break;
819 case T_SHORT: case T_CHAR: // 2 bytes
820 assert(value->type() == T_INT, "Agreement.");
821 val = value->get_int();
822 _obj->short_field_put(offset, (jshort)*((jint*)&val));
823 break;
825 case T_BOOLEAN: case T_BYTE: // 1 byte
826 assert(value->type() == T_INT, "Agreement.");
827 val = value->get_int();
828 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
829 break;
831 default:
832 ShouldNotReachHere();
833 }
834 _i++;
835 }
836 };
838 // restore elements of an eliminated type array
839 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
840 int index = 0;
841 intptr_t val;
843 for (int i = 0; i < sv->field_size(); i++) {
844 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
845 switch(type) {
846 case T_LONG: case T_DOUBLE: {
847 assert(value->type() == T_INT, "Agreement.");
848 StackValue* low =
849 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
850 #ifdef _LP64
851 jlong res = (jlong)low->get_int();
852 #else
853 #ifdef SPARC
854 // For SPARC we have to swap high and low words.
855 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
856 #else
857 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
858 #endif //SPARC
859 #endif
860 obj->long_at_put(index, res);
861 break;
862 }
864 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
865 case T_INT: case T_FLOAT: // 4 bytes.
866 assert(value->type() == T_INT, "Agreement.");
867 val = value->get_int();
868 obj->int_at_put(index, (jint)*((jint*)&val));
869 break;
871 case T_SHORT: case T_CHAR: // 2 bytes
872 assert(value->type() == T_INT, "Agreement.");
873 val = value->get_int();
874 obj->short_at_put(index, (jshort)*((jint*)&val));
875 break;
877 case T_BOOLEAN: case T_BYTE: // 1 byte
878 assert(value->type() == T_INT, "Agreement.");
879 val = value->get_int();
880 obj->bool_at_put(index, (jboolean)*((jint*)&val));
881 break;
883 default:
884 ShouldNotReachHere();
885 }
886 index++;
887 }
888 }
891 // restore fields of an eliminated object array
892 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
893 for (int i = 0; i < sv->field_size(); i++) {
894 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
895 assert(value->type() == T_OBJECT, "object element expected");
896 obj->obj_at_put(i, value->get_obj()());
897 }
898 }
901 // restore fields of all eliminated objects and arrays
902 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
903 for (int i = 0; i < objects->length(); i++) {
904 ObjectValue* sv = (ObjectValue*) objects->at(i);
905 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
906 Handle obj = sv->value();
907 assert(obj.not_null(), "reallocation was missed");
909 if (k->oop_is_instance()) {
910 instanceKlass* ik = instanceKlass::cast(k());
911 FieldReassigner reassign(fr, reg_map, sv, obj());
912 ik->do_nonstatic_fields(&reassign);
913 } else if (k->oop_is_typeArray()) {
914 typeArrayKlass* ak = typeArrayKlass::cast(k());
915 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
916 } else if (k->oop_is_objArray()) {
917 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
918 }
919 }
920 }
923 // relock objects for which synchronization was eliminated
924 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
925 for (int i = 0; i < monitors->length(); i++) {
926 MonitorInfo* mon_info = monitors->at(i);
927 if (mon_info->eliminated()) {
928 assert(mon_info->owner() != NULL, "reallocation was missed");
929 Handle obj = Handle(mon_info->owner());
930 markOop mark = obj->mark();
931 if (UseBiasedLocking && mark->has_bias_pattern()) {
932 // New allocated objects may have the mark set to anonymously biased.
933 // Also the deoptimized method may called methods with synchronization
934 // where the thread-local object is bias locked to the current thread.
935 assert(mark->is_biased_anonymously() ||
936 mark->biased_locker() == thread, "should be locked to current thread");
937 // Reset mark word to unbiased prototype.
938 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
939 obj->set_mark(unbiased_prototype);
940 }
941 BasicLock* lock = mon_info->lock();
942 ObjectSynchronizer::slow_enter(obj, lock, thread);
943 }
944 assert(mon_info->owner()->is_locked(), "object must be locked now");
945 }
946 }
949 #ifndef PRODUCT
950 // print information about reallocated objects
951 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
952 fieldDescriptor fd;
954 for (int i = 0; i < objects->length(); i++) {
955 ObjectValue* sv = (ObjectValue*) objects->at(i);
956 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
957 Handle obj = sv->value();
959 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
960 k->as_klassOop()->print_value();
961 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
962 tty->cr();
964 if (Verbose) {
965 k->oop_print_on(obj(), tty);
966 }
967 }
968 }
969 #endif
970 #endif // COMPILER2
972 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
974 #ifndef PRODUCT
975 if (TraceDeoptimization) {
976 ttyLocker ttyl;
977 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
978 fr.print_on(tty);
979 tty->print_cr(" Virtual frames (innermost first):");
980 for (int index = 0; index < chunk->length(); index++) {
981 compiledVFrame* vf = chunk->at(index);
982 tty->print(" %2d - ", index);
983 vf->print_value();
984 int bci = chunk->at(index)->raw_bci();
985 const char* code_name;
986 if (bci == SynchronizationEntryBCI) {
987 code_name = "sync entry";
988 } else {
989 Bytecodes::Code code = vf->method()->code_at(bci);
990 code_name = Bytecodes::name(code);
991 }
992 tty->print(" - %s", code_name);
993 tty->print_cr(" @ bci %d ", bci);
994 if (Verbose) {
995 vf->print();
996 tty->cr();
997 }
998 }
999 }
1000 #endif
1002 // Register map for next frame (used for stack crawl). We capture
1003 // the state of the deopt'ing frame's caller. Thus if we need to
1004 // stuff a C2I adapter we can properly fill in the callee-save
1005 // register locations.
1006 frame caller = fr.sender(reg_map);
1007 int frame_size = caller.sp() - fr.sp();
1009 frame sender = caller;
1011 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1012 // the vframeArray containing the unpacking information is allocated in the C heap.
1013 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1014 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1016 // Compare the vframeArray to the collected vframes
1017 assert(array->structural_compare(thread, chunk), "just checking");
1018 Events::log("# vframes = %d", (intptr_t)chunk->length());
1020 #ifndef PRODUCT
1021 if (TraceDeoptimization) {
1022 ttyLocker ttyl;
1023 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1024 }
1025 #endif // PRODUCT
1027 return array;
1028 }
1031 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1032 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1033 for (int i = 0; i < monitors->length(); i++) {
1034 MonitorInfo* mon_info = monitors->at(i);
1035 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1036 objects_to_revoke->append(Handle(mon_info->owner()));
1037 }
1038 }
1039 }
1042 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1043 if (!UseBiasedLocking) {
1044 return;
1045 }
1047 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1049 // Unfortunately we don't have a RegisterMap available in most of
1050 // the places we want to call this routine so we need to walk the
1051 // stack again to update the register map.
1052 if (map == NULL || !map->update_map()) {
1053 StackFrameStream sfs(thread, true);
1054 bool found = false;
1055 while (!found && !sfs.is_done()) {
1056 frame* cur = sfs.current();
1057 sfs.next();
1058 found = cur->id() == fr.id();
1059 }
1060 assert(found, "frame to be deoptimized not found on target thread's stack");
1061 map = sfs.register_map();
1062 }
1064 vframe* vf = vframe::new_vframe(&fr, map, thread);
1065 compiledVFrame* cvf = compiledVFrame::cast(vf);
1066 // Revoke monitors' biases in all scopes
1067 while (!cvf->is_top()) {
1068 collect_monitors(cvf, objects_to_revoke);
1069 cvf = compiledVFrame::cast(cvf->sender());
1070 }
1071 collect_monitors(cvf, objects_to_revoke);
1073 if (SafepointSynchronize::is_at_safepoint()) {
1074 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1075 } else {
1076 BiasedLocking::revoke(objects_to_revoke);
1077 }
1078 }
1081 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1082 if (!UseBiasedLocking) {
1083 return;
1084 }
1086 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1087 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1088 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1089 if (jt->has_last_Java_frame()) {
1090 StackFrameStream sfs(jt, true);
1091 while (!sfs.is_done()) {
1092 frame* cur = sfs.current();
1093 if (cb->contains(cur->pc())) {
1094 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1095 compiledVFrame* cvf = compiledVFrame::cast(vf);
1096 // Revoke monitors' biases in all scopes
1097 while (!cvf->is_top()) {
1098 collect_monitors(cvf, objects_to_revoke);
1099 cvf = compiledVFrame::cast(cvf->sender());
1100 }
1101 collect_monitors(cvf, objects_to_revoke);
1102 }
1103 sfs.next();
1104 }
1105 }
1106 }
1107 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1108 }
1111 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1112 assert(fr.can_be_deoptimized(), "checking frame type");
1114 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1116 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1118 // Patch the nmethod so that when execution returns to it we will
1119 // deopt the execution state and return to the interpreter.
1120 fr.deoptimize(thread);
1121 }
1123 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1124 // Deoptimize only if the frame comes from compile code.
1125 // Do not deoptimize the frame which is already patched
1126 // during the execution of the loops below.
1127 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1128 return;
1129 }
1130 ResourceMark rm;
1131 DeoptimizationMarker dm;
1132 if (UseBiasedLocking) {
1133 revoke_biases_of_monitors(thread, fr, map);
1134 }
1135 deoptimize_single_frame(thread, fr);
1137 }
1140 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1141 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1142 "can only deoptimize other thread at a safepoint");
1143 // Compute frame and register map based on thread and sp.
1144 RegisterMap reg_map(thread, UseBiasedLocking);
1145 frame fr = thread->last_frame();
1146 while (fr.id() != id) {
1147 fr = fr.sender(®_map);
1148 }
1149 deoptimize(thread, fr, ®_map);
1150 }
1153 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1154 if (thread == Thread::current()) {
1155 Deoptimization::deoptimize_frame_internal(thread, id);
1156 } else {
1157 VM_DeoptimizeFrame deopt(thread, id);
1158 VMThread::execute(&deopt);
1159 }
1160 }
1163 // JVMTI PopFrame support
1164 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1165 {
1166 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1167 }
1168 JRT_END
1171 #if defined(COMPILER2) || defined(SHARK)
1172 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1173 // in case of an unresolved klass entry, load the class.
1174 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1175 klassOop tk = constant_pool->klass_at(index, CHECK);
1176 return;
1177 }
1179 if (!constant_pool->tag_at(index).is_symbol()) return;
1181 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1182 Symbol* symbol = constant_pool->symbol_at(index);
1184 // class name?
1185 if (symbol->byte_at(0) != '(') {
1186 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1187 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1188 return;
1189 }
1191 // then it must be a signature!
1192 ResourceMark rm(THREAD);
1193 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1194 if (ss.is_object()) {
1195 Symbol* class_name = ss.as_symbol(CHECK);
1196 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1197 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1198 }
1199 }
1200 }
1203 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1204 EXCEPTION_MARK;
1205 load_class_by_index(constant_pool, index, THREAD);
1206 if (HAS_PENDING_EXCEPTION) {
1207 // Exception happened during classloading. We ignore the exception here, since it
1208 // is going to be rethrown since the current activation is going to be deoptimzied and
1209 // the interpreter will re-execute the bytecode.
1210 CLEAR_PENDING_EXCEPTION;
1211 }
1212 }
1214 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1215 HandleMark hm;
1217 // uncommon_trap() is called at the beginning of the uncommon trap
1218 // handler. Note this fact before we start generating temporary frames
1219 // that can confuse an asynchronous stack walker. This counter is
1220 // decremented at the end of unpack_frames().
1221 thread->inc_in_deopt_handler();
1223 // We need to update the map if we have biased locking.
1224 RegisterMap reg_map(thread, UseBiasedLocking);
1225 frame stub_frame = thread->last_frame();
1226 frame fr = stub_frame.sender(®_map);
1227 // Make sure the calling nmethod is not getting deoptimized and removed
1228 // before we are done with it.
1229 nmethodLocker nl(fr.pc());
1231 {
1232 ResourceMark rm;
1234 // Revoke biases of any monitors in the frame to ensure we can migrate them
1235 revoke_biases_of_monitors(thread, fr, ®_map);
1237 DeoptReason reason = trap_request_reason(trap_request);
1238 DeoptAction action = trap_request_action(trap_request);
1239 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1241 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1242 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1243 compiledVFrame* cvf = compiledVFrame::cast(vf);
1245 nmethod* nm = cvf->code();
1247 ScopeDesc* trap_scope = cvf->scope();
1248 methodHandle trap_method = trap_scope->method();
1249 int trap_bci = trap_scope->bci();
1250 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1252 // Record this event in the histogram.
1253 gather_statistics(reason, action, trap_bc);
1255 // Ensure that we can record deopt. history:
1256 bool create_if_missing = ProfileTraps;
1258 methodDataHandle trap_mdo
1259 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1261 // Print a bunch of diagnostics, if requested.
1262 if (TraceDeoptimization || LogCompilation) {
1263 ResourceMark rm;
1264 ttyLocker ttyl;
1265 char buf[100];
1266 if (xtty != NULL) {
1267 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1268 os::current_thread_id(),
1269 format_trap_request(buf, sizeof(buf), trap_request));
1270 nm->log_identity(xtty);
1271 }
1272 Symbol* class_name = NULL;
1273 bool unresolved = false;
1274 if (unloaded_class_index >= 0) {
1275 constantPoolHandle constants (THREAD, trap_method->constants());
1276 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1277 class_name = constants->klass_name_at(unloaded_class_index);
1278 unresolved = true;
1279 if (xtty != NULL)
1280 xtty->print(" unresolved='1'");
1281 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1282 class_name = constants->symbol_at(unloaded_class_index);
1283 }
1284 if (xtty != NULL)
1285 xtty->name(class_name);
1286 }
1287 if (xtty != NULL && trap_mdo.not_null()) {
1288 // Dump the relevant MDO state.
1289 // This is the deopt count for the current reason, any previous
1290 // reasons or recompiles seen at this point.
1291 int dcnt = trap_mdo->trap_count(reason);
1292 if (dcnt != 0)
1293 xtty->print(" count='%d'", dcnt);
1294 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1295 int dos = (pdata == NULL)? 0: pdata->trap_state();
1296 if (dos != 0) {
1297 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1298 if (trap_state_is_recompiled(dos)) {
1299 int recnt2 = trap_mdo->overflow_recompile_count();
1300 if (recnt2 != 0)
1301 xtty->print(" recompiles2='%d'", recnt2);
1302 }
1303 }
1304 }
1305 if (xtty != NULL) {
1306 xtty->stamp();
1307 xtty->end_head();
1308 }
1309 if (TraceDeoptimization) { // make noise on the tty
1310 tty->print("Uncommon trap occurred in");
1311 nm->method()->print_short_name(tty);
1312 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1313 fr.pc(),
1314 (int) os::current_thread_id(),
1315 trap_reason_name(reason),
1316 trap_action_name(action),
1317 unloaded_class_index);
1318 if (class_name != NULL) {
1319 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1320 class_name->print_symbol_on(tty);
1321 }
1322 tty->cr();
1323 }
1324 if (xtty != NULL) {
1325 // Log the precise location of the trap.
1326 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1327 xtty->begin_elem("jvms bci='%d'", sd->bci());
1328 xtty->method(sd->method());
1329 xtty->end_elem();
1330 if (sd->is_top()) break;
1331 }
1332 xtty->tail("uncommon_trap");
1333 }
1334 }
1335 // (End diagnostic printout.)
1337 // Load class if necessary
1338 if (unloaded_class_index >= 0) {
1339 constantPoolHandle constants(THREAD, trap_method->constants());
1340 load_class_by_index(constants, unloaded_class_index);
1341 }
1343 // Flush the nmethod if necessary and desirable.
1344 //
1345 // We need to avoid situations where we are re-flushing the nmethod
1346 // because of a hot deoptimization site. Repeated flushes at the same
1347 // point need to be detected by the compiler and avoided. If the compiler
1348 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1349 // module must take measures to avoid an infinite cycle of recompilation
1350 // and deoptimization. There are several such measures:
1351 //
1352 // 1. If a recompilation is ordered a second time at some site X
1353 // and for the same reason R, the action is adjusted to 'reinterpret',
1354 // to give the interpreter time to exercise the method more thoroughly.
1355 // If this happens, the method's overflow_recompile_count is incremented.
1356 //
1357 // 2. If the compiler fails to reduce the deoptimization rate, then
1358 // the method's overflow_recompile_count will begin to exceed the set
1359 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1360 // is adjusted to 'make_not_compilable', and the method is abandoned
1361 // to the interpreter. This is a performance hit for hot methods,
1362 // but is better than a disastrous infinite cycle of recompilations.
1363 // (Actually, only the method containing the site X is abandoned.)
1364 //
1365 // 3. In parallel with the previous measures, if the total number of
1366 // recompilations of a method exceeds the much larger set limit
1367 // PerMethodRecompilationCutoff, the method is abandoned.
1368 // This should only happen if the method is very large and has
1369 // many "lukewarm" deoptimizations. The code which enforces this
1370 // limit is elsewhere (class nmethod, class methodOopDesc).
1371 //
1372 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1373 // to recompile at each bytecode independently of the per-BCI cutoff.
1374 //
1375 // The decision to update code is up to the compiler, and is encoded
1376 // in the Action_xxx code. If the compiler requests Action_none
1377 // no trap state is changed, no compiled code is changed, and the
1378 // computation suffers along in the interpreter.
1379 //
1380 // The other action codes specify various tactics for decompilation
1381 // and recompilation. Action_maybe_recompile is the loosest, and
1382 // allows the compiled code to stay around until enough traps are seen,
1383 // and until the compiler gets around to recompiling the trapping method.
1384 //
1385 // The other actions cause immediate removal of the present code.
1387 bool update_trap_state = true;
1388 bool make_not_entrant = false;
1389 bool make_not_compilable = false;
1390 bool reprofile = false;
1391 switch (action) {
1392 case Action_none:
1393 // Keep the old code.
1394 update_trap_state = false;
1395 break;
1396 case Action_maybe_recompile:
1397 // Do not need to invalidate the present code, but we can
1398 // initiate another
1399 // Start compiler without (necessarily) invalidating the nmethod.
1400 // The system will tolerate the old code, but new code should be
1401 // generated when possible.
1402 break;
1403 case Action_reinterpret:
1404 // Go back into the interpreter for a while, and then consider
1405 // recompiling form scratch.
1406 make_not_entrant = true;
1407 // Reset invocation counter for outer most method.
1408 // This will allow the interpreter to exercise the bytecodes
1409 // for a while before recompiling.
1410 // By contrast, Action_make_not_entrant is immediate.
1411 //
1412 // Note that the compiler will track null_check, null_assert,
1413 // range_check, and class_check events and log them as if they
1414 // had been traps taken from compiled code. This will update
1415 // the MDO trap history so that the next compilation will
1416 // properly detect hot trap sites.
1417 reprofile = true;
1418 break;
1419 case Action_make_not_entrant:
1420 // Request immediate recompilation, and get rid of the old code.
1421 // Make them not entrant, so next time they are called they get
1422 // recompiled. Unloaded classes are loaded now so recompile before next
1423 // time they are called. Same for uninitialized. The interpreter will
1424 // link the missing class, if any.
1425 make_not_entrant = true;
1426 break;
1427 case Action_make_not_compilable:
1428 // Give up on compiling this method at all.
1429 make_not_entrant = true;
1430 make_not_compilable = true;
1431 break;
1432 default:
1433 ShouldNotReachHere();
1434 }
1436 // Setting +ProfileTraps fixes the following, on all platforms:
1437 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1438 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1439 // recompile relies on a methodDataOop to record heroic opt failures.
1441 // Whether the interpreter is producing MDO data or not, we also need
1442 // to use the MDO to detect hot deoptimization points and control
1443 // aggressive optimization.
1444 bool inc_recompile_count = false;
1445 ProfileData* pdata = NULL;
1446 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1447 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1448 uint this_trap_count = 0;
1449 bool maybe_prior_trap = false;
1450 bool maybe_prior_recompile = false;
1451 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1452 //outputs:
1453 this_trap_count,
1454 maybe_prior_trap,
1455 maybe_prior_recompile);
1456 // Because the interpreter also counts null, div0, range, and class
1457 // checks, these traps from compiled code are double-counted.
1458 // This is harmless; it just means that the PerXTrapLimit values
1459 // are in effect a little smaller than they look.
1461 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1462 if (per_bc_reason != Reason_none) {
1463 // Now take action based on the partially known per-BCI history.
1464 if (maybe_prior_trap
1465 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1466 // If there are too many traps at this BCI, force a recompile.
1467 // This will allow the compiler to see the limit overflow, and
1468 // take corrective action, if possible. The compiler generally
1469 // does not use the exact PerBytecodeTrapLimit value, but instead
1470 // changes its tactics if it sees any traps at all. This provides
1471 // a little hysteresis, delaying a recompile until a trap happens
1472 // several times.
1473 //
1474 // Actually, since there is only one bit of counter per BCI,
1475 // the possible per-BCI counts are {0,1,(per-method count)}.
1476 // This produces accurate results if in fact there is only
1477 // one hot trap site, but begins to get fuzzy if there are
1478 // many sites. For example, if there are ten sites each
1479 // trapping two or more times, they each get the blame for
1480 // all of their traps.
1481 make_not_entrant = true;
1482 }
1484 // Detect repeated recompilation at the same BCI, and enforce a limit.
1485 if (make_not_entrant && maybe_prior_recompile) {
1486 // More than one recompile at this point.
1487 inc_recompile_count = maybe_prior_trap;
1488 }
1489 } else {
1490 // For reasons which are not recorded per-bytecode, we simply
1491 // force recompiles unconditionally.
1492 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1493 make_not_entrant = true;
1494 }
1496 // Go back to the compiler if there are too many traps in this method.
1497 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1498 // If there are too many traps in this method, force a recompile.
1499 // This will allow the compiler to see the limit overflow, and
1500 // take corrective action, if possible.
1501 // (This condition is an unlikely backstop only, because the
1502 // PerBytecodeTrapLimit is more likely to take effect first,
1503 // if it is applicable.)
1504 make_not_entrant = true;
1505 }
1507 // Here's more hysteresis: If there has been a recompile at
1508 // this trap point already, run the method in the interpreter
1509 // for a while to exercise it more thoroughly.
1510 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1511 reprofile = true;
1512 }
1514 }
1516 // Take requested actions on the method:
1518 // Recompile
1519 if (make_not_entrant) {
1520 if (!nm->make_not_entrant()) {
1521 return; // the call did not change nmethod's state
1522 }
1524 if (pdata != NULL) {
1525 // Record the recompilation event, if any.
1526 int tstate0 = pdata->trap_state();
1527 int tstate1 = trap_state_set_recompiled(tstate0, true);
1528 if (tstate1 != tstate0)
1529 pdata->set_trap_state(tstate1);
1530 }
1531 }
1533 if (inc_recompile_count) {
1534 trap_mdo->inc_overflow_recompile_count();
1535 if ((uint)trap_mdo->overflow_recompile_count() >
1536 (uint)PerBytecodeRecompilationCutoff) {
1537 // Give up on the method containing the bad BCI.
1538 if (trap_method() == nm->method()) {
1539 make_not_compilable = true;
1540 } else {
1541 trap_method->set_not_compilable(CompLevel_full_optimization);
1542 // But give grace to the enclosing nm->method().
1543 }
1544 }
1545 }
1547 // Reprofile
1548 if (reprofile) {
1549 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1550 }
1552 // Give up compiling
1553 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1554 assert(make_not_entrant, "consistent");
1555 nm->method()->set_not_compilable(CompLevel_full_optimization);
1556 }
1558 } // Free marked resources
1560 }
1561 JRT_END
1563 methodDataOop
1564 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1565 bool create_if_missing) {
1566 Thread* THREAD = thread;
1567 methodDataOop mdo = m()->method_data();
1568 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1569 // Build an MDO. Ignore errors like OutOfMemory;
1570 // that simply means we won't have an MDO to update.
1571 methodOopDesc::build_interpreter_method_data(m, THREAD);
1572 if (HAS_PENDING_EXCEPTION) {
1573 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1574 CLEAR_PENDING_EXCEPTION;
1575 }
1576 mdo = m()->method_data();
1577 }
1578 return mdo;
1579 }
1581 ProfileData*
1582 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1583 int trap_bci,
1584 Deoptimization::DeoptReason reason,
1585 //outputs:
1586 uint& ret_this_trap_count,
1587 bool& ret_maybe_prior_trap,
1588 bool& ret_maybe_prior_recompile) {
1589 uint prior_trap_count = trap_mdo->trap_count(reason);
1590 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1592 // If the runtime cannot find a place to store trap history,
1593 // it is estimated based on the general condition of the method.
1594 // If the method has ever been recompiled, or has ever incurred
1595 // a trap with the present reason , then this BCI is assumed
1596 // (pessimistically) to be the culprit.
1597 bool maybe_prior_trap = (prior_trap_count != 0);
1598 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1599 ProfileData* pdata = NULL;
1602 // For reasons which are recorded per bytecode, we check per-BCI data.
1603 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1604 if (per_bc_reason != Reason_none) {
1605 // Find the profile data for this BCI. If there isn't one,
1606 // try to allocate one from the MDO's set of spares.
1607 // This will let us detect a repeated trap at this point.
1608 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1610 if (pdata != NULL) {
1611 // Query the trap state of this profile datum.
1612 int tstate0 = pdata->trap_state();
1613 if (!trap_state_has_reason(tstate0, per_bc_reason))
1614 maybe_prior_trap = false;
1615 if (!trap_state_is_recompiled(tstate0))
1616 maybe_prior_recompile = false;
1618 // Update the trap state of this profile datum.
1619 int tstate1 = tstate0;
1620 // Record the reason.
1621 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1622 // Store the updated state on the MDO, for next time.
1623 if (tstate1 != tstate0)
1624 pdata->set_trap_state(tstate1);
1625 } else {
1626 if (LogCompilation && xtty != NULL) {
1627 ttyLocker ttyl;
1628 // Missing MDP? Leave a small complaint in the log.
1629 xtty->elem("missing_mdp bci='%d'", trap_bci);
1630 }
1631 }
1632 }
1634 // Return results:
1635 ret_this_trap_count = this_trap_count;
1636 ret_maybe_prior_trap = maybe_prior_trap;
1637 ret_maybe_prior_recompile = maybe_prior_recompile;
1638 return pdata;
1639 }
1641 void
1642 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1643 ResourceMark rm;
1644 // Ignored outputs:
1645 uint ignore_this_trap_count;
1646 bool ignore_maybe_prior_trap;
1647 bool ignore_maybe_prior_recompile;
1648 query_update_method_data(trap_mdo, trap_bci,
1649 (DeoptReason)reason,
1650 ignore_this_trap_count,
1651 ignore_maybe_prior_trap,
1652 ignore_maybe_prior_recompile);
1653 }
1655 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1657 // Still in Java no safepoints
1658 {
1659 // This enters VM and may safepoint
1660 uncommon_trap_inner(thread, trap_request);
1661 }
1662 return fetch_unroll_info_helper(thread);
1663 }
1665 // Local derived constants.
1666 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1667 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1668 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1670 //---------------------------trap_state_reason---------------------------------
1671 Deoptimization::DeoptReason
1672 Deoptimization::trap_state_reason(int trap_state) {
1673 // This assert provides the link between the width of DataLayout::trap_bits
1674 // and the encoding of "recorded" reasons. It ensures there are enough
1675 // bits to store all needed reasons in the per-BCI MDO profile.
1676 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1677 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1678 trap_state -= recompile_bit;
1679 if (trap_state == DS_REASON_MASK) {
1680 return Reason_many;
1681 } else {
1682 assert((int)Reason_none == 0, "state=0 => Reason_none");
1683 return (DeoptReason)trap_state;
1684 }
1685 }
1686 //-------------------------trap_state_has_reason-------------------------------
1687 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1688 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1689 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1690 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1691 trap_state -= recompile_bit;
1692 if (trap_state == DS_REASON_MASK) {
1693 return -1; // true, unspecifically (bottom of state lattice)
1694 } else if (trap_state == reason) {
1695 return 1; // true, definitely
1696 } else if (trap_state == 0) {
1697 return 0; // false, definitely (top of state lattice)
1698 } else {
1699 return 0; // false, definitely
1700 }
1701 }
1702 //-------------------------trap_state_add_reason-------------------------------
1703 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1704 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1705 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1706 trap_state -= recompile_bit;
1707 if (trap_state == DS_REASON_MASK) {
1708 return trap_state + recompile_bit; // already at state lattice bottom
1709 } else if (trap_state == reason) {
1710 return trap_state + recompile_bit; // the condition is already true
1711 } else if (trap_state == 0) {
1712 return reason + recompile_bit; // no condition has yet been true
1713 } else {
1714 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1715 }
1716 }
1717 //-----------------------trap_state_is_recompiled------------------------------
1718 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1719 return (trap_state & DS_RECOMPILE_BIT) != 0;
1720 }
1721 //-----------------------trap_state_set_recompiled-----------------------------
1722 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1723 if (z) return trap_state | DS_RECOMPILE_BIT;
1724 else return trap_state & ~DS_RECOMPILE_BIT;
1725 }
1726 //---------------------------format_trap_state---------------------------------
1727 // This is used for debugging and diagnostics, including hotspot.log output.
1728 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1729 int trap_state) {
1730 DeoptReason reason = trap_state_reason(trap_state);
1731 bool recomp_flag = trap_state_is_recompiled(trap_state);
1732 // Re-encode the state from its decoded components.
1733 int decoded_state = 0;
1734 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1735 decoded_state = trap_state_add_reason(decoded_state, reason);
1736 if (recomp_flag)
1737 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1738 // If the state re-encodes properly, format it symbolically.
1739 // Because this routine is used for debugging and diagnostics,
1740 // be robust even if the state is a strange value.
1741 size_t len;
1742 if (decoded_state != trap_state) {
1743 // Random buggy state that doesn't decode??
1744 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1745 } else {
1746 len = jio_snprintf(buf, buflen, "%s%s",
1747 trap_reason_name(reason),
1748 recomp_flag ? " recompiled" : "");
1749 }
1750 if (len >= buflen)
1751 buf[buflen-1] = '\0';
1752 return buf;
1753 }
1756 //--------------------------------statics--------------------------------------
1757 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1758 = Deoptimization::Action_reinterpret;
1759 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1760 // Note: Keep this in sync. with enum DeoptReason.
1761 "none",
1762 "null_check",
1763 "null_assert",
1764 "range_check",
1765 "class_check",
1766 "array_check",
1767 "intrinsic",
1768 "bimorphic",
1769 "unloaded",
1770 "uninitialized",
1771 "unreached",
1772 "unhandled",
1773 "constraint",
1774 "div0_check",
1775 "age",
1776 "predicate",
1777 "loop_limit_check"
1778 };
1779 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1780 // Note: Keep this in sync. with enum DeoptAction.
1781 "none",
1782 "maybe_recompile",
1783 "reinterpret",
1784 "make_not_entrant",
1785 "make_not_compilable"
1786 };
1788 const char* Deoptimization::trap_reason_name(int reason) {
1789 if (reason == Reason_many) return "many";
1790 if ((uint)reason < Reason_LIMIT)
1791 return _trap_reason_name[reason];
1792 static char buf[20];
1793 sprintf(buf, "reason%d", reason);
1794 return buf;
1795 }
1796 const char* Deoptimization::trap_action_name(int action) {
1797 if ((uint)action < Action_LIMIT)
1798 return _trap_action_name[action];
1799 static char buf[20];
1800 sprintf(buf, "action%d", action);
1801 return buf;
1802 }
1804 // This is used for debugging and diagnostics, including hotspot.log output.
1805 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1806 int trap_request) {
1807 jint unloaded_class_index = trap_request_index(trap_request);
1808 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1809 const char* action = trap_action_name(trap_request_action(trap_request));
1810 size_t len;
1811 if (unloaded_class_index < 0) {
1812 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1813 reason, action);
1814 } else {
1815 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1816 reason, action, unloaded_class_index);
1817 }
1818 if (len >= buflen)
1819 buf[buflen-1] = '\0';
1820 return buf;
1821 }
1823 juint Deoptimization::_deoptimization_hist
1824 [Deoptimization::Reason_LIMIT]
1825 [1 + Deoptimization::Action_LIMIT]
1826 [Deoptimization::BC_CASE_LIMIT]
1827 = {0};
1829 enum {
1830 LSB_BITS = 8,
1831 LSB_MASK = right_n_bits(LSB_BITS)
1832 };
1834 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1835 Bytecodes::Code bc) {
1836 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1837 assert(action >= 0 && action < Action_LIMIT, "oob");
1838 _deoptimization_hist[Reason_none][0][0] += 1; // total
1839 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1840 juint* cases = _deoptimization_hist[reason][1+action];
1841 juint* bc_counter_addr = NULL;
1842 juint bc_counter = 0;
1843 // Look for an unused counter, or an exact match to this BC.
1844 if (bc != Bytecodes::_illegal) {
1845 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1846 juint* counter_addr = &cases[bc_case];
1847 juint counter = *counter_addr;
1848 if ((counter == 0 && bc_counter_addr == NULL)
1849 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1850 // this counter is either free or is already devoted to this BC
1851 bc_counter_addr = counter_addr;
1852 bc_counter = counter | bc;
1853 }
1854 }
1855 }
1856 if (bc_counter_addr == NULL) {
1857 // Overflow, or no given bytecode.
1858 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1859 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1860 }
1861 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1862 }
1864 jint Deoptimization::total_deoptimization_count() {
1865 return _deoptimization_hist[Reason_none][0][0];
1866 }
1868 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1869 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1870 return _deoptimization_hist[reason][0][0];
1871 }
1873 void Deoptimization::print_statistics() {
1874 juint total = total_deoptimization_count();
1875 juint account = total;
1876 if (total != 0) {
1877 ttyLocker ttyl;
1878 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1879 tty->print_cr("Deoptimization traps recorded:");
1880 #define PRINT_STAT_LINE(name, r) \
1881 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1882 PRINT_STAT_LINE("total", total);
1883 // For each non-zero entry in the histogram, print the reason,
1884 // the action, and (if specifically known) the type of bytecode.
1885 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1886 for (int action = 0; action < Action_LIMIT; action++) {
1887 juint* cases = _deoptimization_hist[reason][1+action];
1888 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1889 juint counter = cases[bc_case];
1890 if (counter != 0) {
1891 char name[1*K];
1892 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1893 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1894 bc = Bytecodes::_illegal;
1895 sprintf(name, "%s/%s/%s",
1896 trap_reason_name(reason),
1897 trap_action_name(action),
1898 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1899 juint r = counter >> LSB_BITS;
1900 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1901 account -= r;
1902 }
1903 }
1904 }
1905 }
1906 if (account != 0) {
1907 PRINT_STAT_LINE("unaccounted", account);
1908 }
1909 #undef PRINT_STAT_LINE
1910 if (xtty != NULL) xtty->tail("statistics");
1911 }
1912 }
1913 #else // COMPILER2 || SHARK
1916 // Stubs for C1 only system.
1917 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1918 return false;
1919 }
1921 const char* Deoptimization::trap_reason_name(int reason) {
1922 return "unknown";
1923 }
1925 void Deoptimization::print_statistics() {
1926 // no output
1927 }
1929 void
1930 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1931 // no udpate
1932 }
1934 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1935 return 0;
1936 }
1938 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1939 Bytecodes::Code bc) {
1940 // no update
1941 }
1943 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1944 int trap_state) {
1945 jio_snprintf(buf, buflen, "#%d", trap_state);
1946 return buf;
1947 }
1949 #endif // COMPILER2 || SHARK