Thu, 29 Sep 2016 09:54:38 +0800
8049252: VerifyStack logic in Deoptimization::unpack_frames does not expect to see invoke bc at the top frame during normal deoptimization
see: http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/rev/e0c6fadce66e
1 /*
2 * Copyright (c) 1997, 2014, 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 */
25 /*
26 * This file has been modified by Loongson Technology in 2015. These
27 * modifications are Copyright (c) 2015 Loongson Technology, and are made
28 * available on the same license terms set forth above.
29 */
31 #include "precompiled.hpp"
32 #include "classfile/systemDictionary.hpp"
33 #include "code/debugInfoRec.hpp"
34 #include "code/nmethod.hpp"
35 #include "code/pcDesc.hpp"
36 #include "code/scopeDesc.hpp"
37 #include "interpreter/bytecode.hpp"
38 #include "interpreter/interpreter.hpp"
39 #include "interpreter/oopMapCache.hpp"
40 #include "memory/allocation.inline.hpp"
41 #include "memory/oopFactory.hpp"
42 #include "memory/resourceArea.hpp"
43 #include "oops/method.hpp"
44 #include "oops/oop.inline.hpp"
45 #include "prims/jvmtiThreadState.hpp"
46 #include "runtime/biasedLocking.hpp"
47 #include "runtime/compilationPolicy.hpp"
48 #include "runtime/deoptimization.hpp"
49 #include "runtime/interfaceSupport.hpp"
50 #include "runtime/sharedRuntime.hpp"
51 #include "runtime/signature.hpp"
52 #include "runtime/stubRoutines.hpp"
53 #include "runtime/thread.hpp"
54 #include "runtime/vframe.hpp"
55 #include "runtime/vframeArray.hpp"
56 #include "runtime/vframe_hp.hpp"
57 #include "utilities/events.hpp"
58 #include "utilities/xmlstream.hpp"
59 #ifdef TARGET_ARCH_x86
60 # include "vmreg_x86.inline.hpp"
61 #endif
62 #ifdef TARGET_ARCH_sparc
63 # include "vmreg_sparc.inline.hpp"
64 #endif
65 #ifdef TARGET_ARCH_zero
66 # include "vmreg_zero.inline.hpp"
67 #endif
68 #ifdef TARGET_ARCH_arm
69 # include "vmreg_arm.inline.hpp"
70 #endif
71 #ifdef TARGET_ARCH_ppc
72 # include "vmreg_ppc.inline.hpp"
73 #endif
74 #ifdef TARGET_ARCH_mips
75 # include "vmreg_mips.inline.hpp"
76 #endif
77 #ifdef COMPILER2
78 #ifdef TARGET_ARCH_MODEL_x86_32
79 # include "adfiles/ad_x86_32.hpp"
80 #endif
81 #ifdef TARGET_ARCH_MODEL_x86_64
82 # include "adfiles/ad_x86_64.hpp"
83 #endif
84 #ifdef TARGET_ARCH_MODEL_sparc
85 # include "adfiles/ad_sparc.hpp"
86 #endif
87 #ifdef TARGET_ARCH_MODEL_zero
88 # include "adfiles/ad_zero.hpp"
89 #endif
90 #ifdef TARGET_ARCH_MODEL_arm
91 # include "adfiles/ad_arm.hpp"
92 #endif
93 #ifdef TARGET_ARCH_MODEL_ppc_32
94 # include "adfiles/ad_ppc_32.hpp"
95 #endif
96 #ifdef TARGET_ARCH_MODEL_ppc_64
97 # include "adfiles/ad_ppc_64.hpp"
98 #endif
99 #ifdef TARGET_ARCH_MODEL_mips_64
100 # include "adfiles/ad_mips_64.hpp"
101 #endif
102 #endif // COMPILER2
104 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
106 bool DeoptimizationMarker::_is_active = false;
108 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
109 int caller_adjustment,
110 int caller_actual_parameters,
111 int number_of_frames,
112 intptr_t* frame_sizes,
113 address* frame_pcs,
114 BasicType return_type) {
115 _size_of_deoptimized_frame = size_of_deoptimized_frame;
116 _caller_adjustment = caller_adjustment;
117 _caller_actual_parameters = caller_actual_parameters;
118 _number_of_frames = number_of_frames;
119 _frame_sizes = frame_sizes;
120 _frame_pcs = frame_pcs;
121 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
122 _return_type = return_type;
123 _initial_info = 0;
124 // PD (x86 only)
125 _counter_temp = 0;
126 _unpack_kind = 0;
127 _sender_sp_temp = 0;
129 _total_frame_sizes = size_of_frames();
130 }
133 Deoptimization::UnrollBlock::~UnrollBlock() {
134 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
135 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
136 FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
137 }
140 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
141 assert(register_number < RegisterMap::reg_count, "checking register number");
142 return &_register_block[register_number * 2];
143 }
147 int Deoptimization::UnrollBlock::size_of_frames() const {
148 // Acount first for the adjustment of the initial frame
149 int result = _caller_adjustment;
150 for (int index = 0; index < number_of_frames(); index++) {
151 result += frame_sizes()[index];
152 }
153 return result;
154 }
157 void Deoptimization::UnrollBlock::print() {
158 ttyLocker ttyl;
159 tty->print_cr("UnrollBlock");
160 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
161 tty->print( " frame_sizes: ");
162 for (int index = 0; index < number_of_frames(); index++) {
163 tty->print("%d ", frame_sizes()[index]);
164 }
165 tty->cr();
166 }
169 // In order to make fetch_unroll_info work properly with escape
170 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
171 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
172 // of previously eliminated objects occurs in realloc_objects, which is
173 // called from the method fetch_unroll_info_helper below.
174 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
175 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
176 // but makes the entry a little slower. There is however a little dance we have to
177 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
179 // fetch_unroll_info() is called at the beginning of the deoptimization
180 // handler. Note this fact before we start generating temporary frames
181 // that can confuse an asynchronous stack walker. This counter is
182 // decremented at the end of unpack_frames().
183 thread->inc_in_deopt_handler();
185 return fetch_unroll_info_helper(thread);
186 JRT_END
189 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
190 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
192 // Note: there is a safepoint safety issue here. No matter whether we enter
193 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
194 // the vframeArray is created.
195 //
197 // Allocate our special deoptimization ResourceMark
198 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
199 assert(thread->deopt_mark() == NULL, "Pending deopt!");
200 thread->set_deopt_mark(dmark);
202 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
203 RegisterMap map(thread, true);
204 RegisterMap dummy_map(thread, false);
205 // Now get the deoptee with a valid map
206 frame deoptee = stub_frame.sender(&map);
207 // Set the deoptee nmethod
208 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
209 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
211 if (VerifyStack) {
212 thread->validate_frame_layout();
213 }
215 // Create a growable array of VFrames where each VFrame represents an inlined
216 // Java frame. This storage is allocated with the usual system arena.
217 assert(deoptee.is_compiled_frame(), "Wrong frame type");
218 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
219 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
220 while (!vf->is_top()) {
221 assert(vf->is_compiled_frame(), "Wrong frame type");
222 chunk->push(compiledVFrame::cast(vf));
223 vf = vf->sender();
224 }
225 assert(vf->is_compiled_frame(), "Wrong frame type");
226 chunk->push(compiledVFrame::cast(vf));
228 #ifdef COMPILER2
229 // Reallocate the non-escaping objects and restore their fields. Then
230 // relock objects if synchronization on them was eliminated.
231 if (DoEscapeAnalysis || EliminateNestedLocks) {
232 if (EliminateAllocations) {
233 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
234 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
236 // The flag return_oop() indicates call sites which return oop
237 // in compiled code. Such sites include java method calls,
238 // runtime calls (for example, used to allocate new objects/arrays
239 // on slow code path) and any other calls generated in compiled code.
240 // It is not guaranteed that we can get such information here only
241 // by analyzing bytecode in deoptimized frames. This is why this flag
242 // is set during method compilation (see Compile::Process_OopMap_Node()).
243 bool save_oop_result = chunk->at(0)->scope()->return_oop();
244 Handle return_value;
245 if (save_oop_result) {
246 // Reallocation may trigger GC. If deoptimization happened on return from
247 // call which returns oop we need to save it since it is not in oopmap.
248 oop result = deoptee.saved_oop_result(&map);
249 assert(result == NULL || result->is_oop(), "must be oop");
250 return_value = Handle(thread, result);
251 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
252 if (TraceDeoptimization) {
253 ttyLocker ttyl;
254 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
255 }
256 }
257 bool reallocated = false;
258 if (objects != NULL) {
259 JRT_BLOCK
260 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
261 JRT_END
262 }
263 if (reallocated) {
264 reassign_fields(&deoptee, &map, objects);
265 #ifndef PRODUCT
266 if (TraceDeoptimization) {
267 ttyLocker ttyl;
268 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
269 print_objects(objects);
270 }
271 #endif
272 }
273 if (save_oop_result) {
274 // Restore result.
275 deoptee.set_saved_oop_result(&map, return_value());
276 }
277 }
278 if (EliminateLocks) {
279 #ifndef PRODUCT
280 bool first = true;
281 #endif
282 for (int i = 0; i < chunk->length(); i++) {
283 compiledVFrame* cvf = chunk->at(i);
284 assert (cvf->scope() != NULL,"expect only compiled java frames");
285 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
286 if (monitors->is_nonempty()) {
287 relock_objects(monitors, thread);
288 #ifndef PRODUCT
289 if (TraceDeoptimization) {
290 ttyLocker ttyl;
291 for (int j = 0; j < monitors->length(); j++) {
292 MonitorInfo* mi = monitors->at(j);
293 if (mi->eliminated()) {
294 if (first) {
295 first = false;
296 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
297 }
298 tty->print_cr(" object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
299 }
300 }
301 }
302 #endif
303 }
304 }
305 }
306 }
307 #endif // COMPILER2
308 // Ensure that no safepoint is taken after pointers have been stored
309 // in fields of rematerialized objects. If a safepoint occurs from here on
310 // out the java state residing in the vframeArray will be missed.
311 No_Safepoint_Verifier no_safepoint;
313 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
315 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
316 thread->set_vframe_array_head(array);
318 // Now that the vframeArray has been created if we have any deferred local writes
319 // added by jvmti then we can free up that structure as the data is now in the
320 // vframeArray
322 if (thread->deferred_locals() != NULL) {
323 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
324 int i = 0;
325 do {
326 // Because of inlining we could have multiple vframes for a single frame
327 // and several of the vframes could have deferred writes. Find them all.
328 if (list->at(i)->id() == array->original().id()) {
329 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
330 list->remove_at(i);
331 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
332 delete dlv;
333 } else {
334 i++;
335 }
336 } while ( i < list->length() );
337 if (list->length() == 0) {
338 thread->set_deferred_locals(NULL);
339 // free the list and elements back to C heap.
340 delete list;
341 }
343 }
345 #ifndef SHARK
346 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
347 CodeBlob* cb = stub_frame.cb();
348 // Verify we have the right vframeArray
349 assert(cb->frame_size() >= 0, "Unexpected frame size");
350 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
352 // If the deopt call site is a MethodHandle invoke call site we have
353 // to adjust the unpack_sp.
354 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
355 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
356 unpack_sp = deoptee.unextended_sp();
358 #ifdef ASSERT
359 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
360 #endif
361 #else
362 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
363 #endif // !SHARK
365 // This is a guarantee instead of an assert because if vframe doesn't match
366 // we will unpack the wrong deoptimized frame and wind up in strange places
367 // where it will be very difficult to figure out what went wrong. Better
368 // to die an early death here than some very obscure death later when the
369 // trail is cold.
370 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
371 // in that it will fail to detect a problem when there is one. This needs
372 // more work in tiger timeframe.
373 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
375 int number_of_frames = array->frames();
377 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
378 // virtual activation, which is the reverse of the elements in the vframes array.
379 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
380 // +1 because we always have an interpreter return address for the final slot.
381 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
382 int popframe_extra_args = 0;
383 // Create an interpreter return address for the stub to use as its return
384 // address so the skeletal frames are perfectly walkable
385 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
387 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
388 // activation be put back on the expression stack of the caller for reexecution
389 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
390 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
391 }
393 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
394 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
395 // than simply use array->sender.pc(). This requires us to walk the current set of frames
396 //
397 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
398 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
400 // It's possible that the number of paramters at the call site is
401 // different than number of arguments in the callee when method
402 // handles are used. If the caller is interpreted get the real
403 // value so that the proper amount of space can be added to it's
404 // frame.
405 bool caller_was_method_handle = false;
406 if (deopt_sender.is_interpreted_frame()) {
407 methodHandle method = deopt_sender.interpreter_frame_method();
408 Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
409 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
410 // Method handle invokes may involve fairly arbitrary chains of
411 // calls so it's impossible to know how much actual space the
412 // caller has for locals.
413 caller_was_method_handle = true;
414 }
415 }
417 //
418 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
419 // frame_sizes/frame_pcs[1] next oldest frame (int)
420 // frame_sizes/frame_pcs[n] youngest frame (int)
421 //
422 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
423 // owns the space for the return address to it's caller). Confusing ain't it.
424 //
425 // The vframe array can address vframes with indices running from
426 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
427 // When we create the skeletal frames we need the oldest frame to be in the zero slot
428 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
429 // so things look a little strange in this loop.
430 //
431 int callee_parameters = 0;
432 int callee_locals = 0;
433 for (int index = 0; index < array->frames(); index++ ) {
434 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
435 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
436 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
437 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
438 callee_locals,
439 index == 0,
440 popframe_extra_args);
441 // This pc doesn't have to be perfect just good enough to identify the frame
442 // as interpreted so the skeleton frame will be walkable
443 // The correct pc will be set when the skeleton frame is completely filled out
444 // The final pc we store in the loop is wrong and will be overwritten below
445 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
447 callee_parameters = array->element(index)->method()->size_of_parameters();
448 callee_locals = array->element(index)->method()->max_locals();
449 popframe_extra_args = 0;
450 }
452 // Compute whether the root vframe returns a float or double value.
453 BasicType return_type;
454 {
455 HandleMark hm;
456 methodHandle method(thread, array->element(0)->method());
457 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
458 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
459 }
461 // Compute information for handling adapters and adjusting the frame size of the caller.
462 int caller_adjustment = 0;
464 // Compute the amount the oldest interpreter frame will have to adjust
465 // its caller's stack by. If the caller is a compiled frame then
466 // we pretend that the callee has no parameters so that the
467 // extension counts for the full amount of locals and not just
468 // locals-parms. This is because without a c2i adapter the parm
469 // area as created by the compiled frame will not be usable by
470 // the interpreter. (Depending on the calling convention there
471 // may not even be enough space).
473 // QQQ I'd rather see this pushed down into last_frame_adjust
474 // and have it take the sender (aka caller).
476 if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
477 caller_adjustment = last_frame_adjust(0, callee_locals);
478 } else if (callee_locals > callee_parameters) {
479 // The caller frame may need extending to accommodate
480 // non-parameter locals of the first unpacked interpreted frame.
481 // Compute that adjustment.
482 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
483 }
485 // If the sender is deoptimized the we must retrieve the address of the handler
486 // since the frame will "magically" show the original pc before the deopt
487 // and we'd undo the deopt.
489 frame_pcs[0] = deopt_sender.raw_pc();
491 #ifndef SHARK
492 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
493 #endif // SHARK
495 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
496 caller_adjustment * BytesPerWord,
497 caller_was_method_handle ? 0 : callee_parameters,
498 number_of_frames,
499 frame_sizes,
500 frame_pcs,
501 return_type);
502 // On some platforms, we need a way to pass some platform dependent
503 // information to the unpacking code so the skeletal frames come out
504 // correct (initial fp value, unextended sp, ...)
505 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
507 if (array->frames() > 1) {
508 if (VerifyStack && TraceDeoptimization) {
509 ttyLocker ttyl;
510 tty->print_cr("Deoptimizing method containing inlining");
511 }
512 }
514 array->set_unroll_block(info);
515 return info;
516 }
518 // Called to cleanup deoptimization data structures in normal case
519 // after unpacking to stack and when stack overflow error occurs
520 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
521 vframeArray *array) {
523 // Get array if coming from exception
524 if (array == NULL) {
525 array = thread->vframe_array_head();
526 }
527 thread->set_vframe_array_head(NULL);
529 // Free the previous UnrollBlock
530 vframeArray* old_array = thread->vframe_array_last();
531 thread->set_vframe_array_last(array);
533 if (old_array != NULL) {
534 UnrollBlock* old_info = old_array->unroll_block();
535 old_array->set_unroll_block(NULL);
536 delete old_info;
537 delete old_array;
538 }
540 // Deallocate any resource creating in this routine and any ResourceObjs allocated
541 // inside the vframeArray (StackValueCollections)
543 delete thread->deopt_mark();
544 thread->set_deopt_mark(NULL);
545 thread->set_deopt_nmethod(NULL);
548 if (JvmtiExport::can_pop_frame()) {
549 #ifndef CC_INTERP
550 // Regardless of whether we entered this routine with the pending
551 // popframe condition bit set, we should always clear it now
552 thread->clear_popframe_condition();
553 #else
554 // C++ interpeter will clear has_pending_popframe when it enters
555 // with method_resume. For deopt_resume2 we clear it now.
556 if (thread->popframe_forcing_deopt_reexecution())
557 thread->clear_popframe_condition();
558 #endif /* CC_INTERP */
559 }
561 // unpack_frames() is called at the end of the deoptimization handler
562 // and (in C2) at the end of the uncommon trap handler. Note this fact
563 // so that an asynchronous stack walker can work again. This counter is
564 // incremented at the beginning of fetch_unroll_info() and (in C2) at
565 // the beginning of uncommon_trap().
566 thread->dec_in_deopt_handler();
567 }
570 // Return BasicType of value being returned
571 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
573 // We are already active int he special DeoptResourceMark any ResourceObj's we
574 // allocate will be freed at the end of the routine.
576 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
577 // but makes the entry a little slower. There is however a little dance we have to
578 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
579 ResetNoHandleMark rnhm; // No-op in release/product versions
580 HandleMark hm;
582 frame stub_frame = thread->last_frame();
584 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
585 // must point to the vframeArray for the unpack frame.
586 vframeArray* array = thread->vframe_array_head();
588 #ifndef PRODUCT
589 if (TraceDeoptimization) {
590 ttyLocker ttyl;
591 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
592 }
593 #endif
594 Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
595 stub_frame.pc(), stub_frame.sp(), exec_mode);
597 UnrollBlock* info = array->unroll_block();
599 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
600 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
602 BasicType bt = info->return_type();
604 // If we have an exception pending, claim that the return type is an oop
605 // so the deopt_blob does not overwrite the exception_oop.
607 if (exec_mode == Unpack_exception)
608 bt = T_OBJECT;
610 // Cleanup thread deopt data
611 cleanup_deopt_info(thread, array);
613 #ifndef PRODUCT
614 if (VerifyStack) {
615 ResourceMark res_mark;
617 thread->validate_frame_layout();
619 // Verify that the just-unpacked frames match the interpreter's
620 // notions of expression stack and locals
621 vframeArray* cur_array = thread->vframe_array_last();
622 RegisterMap rm(thread, false);
623 rm.set_include_argument_oops(false);
624 bool is_top_frame = true;
625 int callee_size_of_parameters = 0;
626 int callee_max_locals = 0;
627 for (int i = 0; i < cur_array->frames(); i++) {
628 vframeArrayElement* el = cur_array->element(i);
629 frame* iframe = el->iframe();
630 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
632 // Get the oop map for this bci
633 InterpreterOopMap mask;
634 int cur_invoke_parameter_size = 0;
635 bool try_next_mask = false;
636 int next_mask_expression_stack_size = -1;
637 int top_frame_expression_stack_adjustment = 0;
638 methodHandle mh(thread, iframe->interpreter_frame_method());
639 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
640 BytecodeStream str(mh);
641 str.set_start(iframe->interpreter_frame_bci());
642 int max_bci = mh->code_size();
643 // Get to the next bytecode if possible
644 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
645 // Check to see if we can grab the number of outgoing arguments
646 // at an uncommon trap for an invoke (where the compiler
647 // generates debug info before the invoke has executed)
648 Bytecodes::Code cur_code = str.next();
649 if (cur_code == Bytecodes::_invokevirtual ||
650 cur_code == Bytecodes::_invokespecial ||
651 cur_code == Bytecodes::_invokestatic ||
652 cur_code == Bytecodes::_invokeinterface ||
653 cur_code == Bytecodes::_invokedynamic) {
654 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
655 Symbol* signature = invoke.signature();
656 ArgumentSizeComputer asc(signature);
657 cur_invoke_parameter_size = asc.size();
658 if (invoke.has_receiver()) {
659 // Add in receiver
660 ++cur_invoke_parameter_size;
661 }
662 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
663 callee_size_of_parameters++;
664 }
665 }
666 if (str.bci() < max_bci) {
667 Bytecodes::Code bc = str.next();
668 if (bc >= 0) {
669 // The interpreter oop map generator reports results before
670 // the current bytecode has executed except in the case of
671 // calls. It seems to be hard to tell whether the compiler
672 // has emitted debug information matching the "state before"
673 // a given bytecode or the state after, so we try both
674 switch (cur_code) {
675 case Bytecodes::_invokevirtual:
676 case Bytecodes::_invokespecial:
677 case Bytecodes::_invokestatic:
678 case Bytecodes::_invokeinterface:
679 case Bytecodes::_invokedynamic:
680 case Bytecodes::_athrow:
681 break;
682 default: {
683 InterpreterOopMap next_mask;
684 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
685 next_mask_expression_stack_size = next_mask.expression_stack_size();
686 // Need to subtract off the size of the result type of
687 // the bytecode because this is not described in the
688 // debug info but returned to the interpreter in the TOS
689 // caching register
690 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
691 if (bytecode_result_type != T_ILLEGAL) {
692 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
693 }
694 assert(top_frame_expression_stack_adjustment >= 0, "");
695 try_next_mask = true;
696 break;
697 }
698 }
699 }
700 }
702 // Verify stack depth and oops in frame
703 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
704 if (!(
705 /* SPARC */
706 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
707 /* x86 */
708 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
709 (try_next_mask &&
710 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
711 top_frame_expression_stack_adjustment))) ||
712 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
713 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
714 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
715 )) {
716 ttyLocker ttyl;
718 // Print out some information that will help us debug the problem
719 tty->print_cr("Wrong number of expression stack elements during deoptimization");
720 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
721 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
722 iframe->interpreter_frame_expression_stack_size());
723 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
724 tty->print_cr(" try_next_mask = %d", try_next_mask);
725 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
726 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
727 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
728 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
729 tty->print_cr(" exec_mode = %d", exec_mode);
730 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
731 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
732 tty->print_cr(" Interpreted frames:");
733 for (int k = 0; k < cur_array->frames(); k++) {
734 vframeArrayElement* el = cur_array->element(k);
735 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
736 }
737 cur_array->print_on_2(tty);
738 guarantee(false, "wrong number of expression stack elements during deopt");
739 }
740 VerifyOopClosure verify;
741 iframe->oops_interpreted_do(&verify, NULL, &rm, false);
742 callee_size_of_parameters = mh->size_of_parameters();
743 callee_max_locals = mh->max_locals();
744 is_top_frame = false;
745 }
746 }
747 #endif /* !PRODUCT */
750 return bt;
751 JRT_END
754 int Deoptimization::deoptimize_dependents() {
755 Threads::deoptimized_wrt_marked_nmethods();
756 return 0;
757 }
760 #ifdef COMPILER2
761 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
762 Handle pending_exception(thread->pending_exception());
763 const char* exception_file = thread->exception_file();
764 int exception_line = thread->exception_line();
765 thread->clear_pending_exception();
767 for (int i = 0; i < objects->length(); i++) {
768 assert(objects->at(i)->is_object(), "invalid debug information");
769 ObjectValue* sv = (ObjectValue*) objects->at(i);
771 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
772 oop obj = NULL;
774 if (k->oop_is_instance()) {
775 InstanceKlass* ik = InstanceKlass::cast(k());
776 obj = ik->allocate_instance(CHECK_(false));
777 } else if (k->oop_is_typeArray()) {
778 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
779 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
780 int len = sv->field_size() / type2size[ak->element_type()];
781 obj = ak->allocate(len, CHECK_(false));
782 } else if (k->oop_is_objArray()) {
783 ObjArrayKlass* ak = ObjArrayKlass::cast(k());
784 obj = ak->allocate(sv->field_size(), CHECK_(false));
785 }
787 assert(obj != NULL, "allocation failed");
788 assert(sv->value().is_null(), "redundant reallocation");
789 sv->set_value(obj);
790 }
792 if (pending_exception.not_null()) {
793 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
794 }
796 return true;
797 }
799 // This assumes that the fields are stored in ObjectValue in the same order
800 // they are yielded by do_nonstatic_fields.
801 class FieldReassigner: public FieldClosure {
802 frame* _fr;
803 RegisterMap* _reg_map;
804 ObjectValue* _sv;
805 InstanceKlass* _ik;
806 oop _obj;
808 int _i;
809 public:
810 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
811 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
813 int i() const { return _i; }
816 void do_field(fieldDescriptor* fd) {
817 intptr_t val;
818 StackValue* value =
819 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
820 int offset = fd->offset();
821 switch (fd->field_type()) {
822 case T_OBJECT: case T_ARRAY:
823 assert(value->type() == T_OBJECT, "Agreement.");
824 _obj->obj_field_put(offset, value->get_obj()());
825 break;
827 case T_LONG: case T_DOUBLE: {
828 assert(value->type() == T_INT, "Agreement.");
829 StackValue* low =
830 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
831 #ifdef _LP64
832 jlong res = (jlong)low->get_int();
833 #else
834 #ifdef SPARC
835 // For SPARC we have to swap high and low words.
836 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
837 #else
838 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
839 #endif //SPARC
840 #endif
841 _obj->long_field_put(offset, res);
842 break;
843 }
844 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
845 case T_INT: case T_FLOAT: // 4 bytes.
846 assert(value->type() == T_INT, "Agreement.");
847 val = value->get_int();
848 _obj->int_field_put(offset, (jint)*((jint*)&val));
849 break;
851 case T_SHORT: case T_CHAR: // 2 bytes
852 assert(value->type() == T_INT, "Agreement.");
853 val = value->get_int();
854 _obj->short_field_put(offset, (jshort)*((jint*)&val));
855 break;
857 case T_BOOLEAN: case T_BYTE: // 1 byte
858 assert(value->type() == T_INT, "Agreement.");
859 val = value->get_int();
860 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
861 break;
863 default:
864 ShouldNotReachHere();
865 }
866 _i++;
867 }
868 };
870 // restore elements of an eliminated type array
871 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
872 int index = 0;
873 intptr_t val;
875 for (int i = 0; i < sv->field_size(); i++) {
876 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
877 switch(type) {
878 case T_LONG: case T_DOUBLE: {
879 assert(value->type() == T_INT, "Agreement.");
880 StackValue* low =
881 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
882 #ifdef _LP64
883 jlong res = (jlong)low->get_int();
884 #else
885 #ifdef SPARC
886 // For SPARC we have to swap high and low words.
887 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
888 #else
889 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
890 #endif //SPARC
891 #endif
892 obj->long_at_put(index, res);
893 break;
894 }
896 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
897 case T_INT: case T_FLOAT: // 4 bytes.
898 assert(value->type() == T_INT, "Agreement.");
899 val = value->get_int();
900 obj->int_at_put(index, (jint)*((jint*)&val));
901 break;
903 case T_SHORT: case T_CHAR: // 2 bytes
904 assert(value->type() == T_INT, "Agreement.");
905 val = value->get_int();
906 obj->short_at_put(index, (jshort)*((jint*)&val));
907 break;
909 case T_BOOLEAN: case T_BYTE: // 1 byte
910 assert(value->type() == T_INT, "Agreement.");
911 val = value->get_int();
912 obj->bool_at_put(index, (jboolean)*((jint*)&val));
913 break;
915 default:
916 ShouldNotReachHere();
917 }
918 index++;
919 }
920 }
923 // restore fields of an eliminated object array
924 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
925 for (int i = 0; i < sv->field_size(); i++) {
926 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
927 assert(value->type() == T_OBJECT, "object element expected");
928 obj->obj_at_put(i, value->get_obj()());
929 }
930 }
933 // restore fields of all eliminated objects and arrays
934 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
935 for (int i = 0; i < objects->length(); i++) {
936 ObjectValue* sv = (ObjectValue*) objects->at(i);
937 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
938 Handle obj = sv->value();
939 assert(obj.not_null(), "reallocation was missed");
941 if (k->oop_is_instance()) {
942 InstanceKlass* ik = InstanceKlass::cast(k());
943 FieldReassigner reassign(fr, reg_map, sv, obj());
944 ik->do_nonstatic_fields(&reassign);
945 } else if (k->oop_is_typeArray()) {
946 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
947 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
948 } else if (k->oop_is_objArray()) {
949 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
950 }
951 }
952 }
955 // relock objects for which synchronization was eliminated
956 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
957 for (int i = 0; i < monitors->length(); i++) {
958 MonitorInfo* mon_info = monitors->at(i);
959 if (mon_info->eliminated()) {
960 assert(mon_info->owner() != NULL, "reallocation was missed");
961 Handle obj = Handle(mon_info->owner());
962 markOop mark = obj->mark();
963 if (UseBiasedLocking && mark->has_bias_pattern()) {
964 // New allocated objects may have the mark set to anonymously biased.
965 // Also the deoptimized method may called methods with synchronization
966 // where the thread-local object is bias locked to the current thread.
967 assert(mark->is_biased_anonymously() ||
968 mark->biased_locker() == thread, "should be locked to current thread");
969 // Reset mark word to unbiased prototype.
970 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
971 obj->set_mark(unbiased_prototype);
972 }
973 BasicLock* lock = mon_info->lock();
974 ObjectSynchronizer::slow_enter(obj, lock, thread);
975 }
976 assert(mon_info->owner()->is_locked(), "object must be locked now");
977 }
978 }
981 #ifndef PRODUCT
982 // print information about reallocated objects
983 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
984 fieldDescriptor fd;
986 for (int i = 0; i < objects->length(); i++) {
987 ObjectValue* sv = (ObjectValue*) objects->at(i);
988 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
989 Handle obj = sv->value();
991 tty->print(" object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
992 k->print_value();
993 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
994 tty->cr();
996 if (Verbose) {
997 k->oop_print_on(obj(), tty);
998 }
999 }
1000 }
1001 #endif
1002 #endif // COMPILER2
1004 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
1005 Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
1007 #ifndef PRODUCT
1008 if (TraceDeoptimization) {
1009 ttyLocker ttyl;
1010 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
1011 fr.print_on(tty);
1012 tty->print_cr(" Virtual frames (innermost first):");
1013 for (int index = 0; index < chunk->length(); index++) {
1014 compiledVFrame* vf = chunk->at(index);
1015 tty->print(" %2d - ", index);
1016 vf->print_value();
1017 int bci = chunk->at(index)->raw_bci();
1018 const char* code_name;
1019 if (bci == SynchronizationEntryBCI) {
1020 code_name = "sync entry";
1021 } else {
1022 Bytecodes::Code code = vf->method()->code_at(bci);
1023 code_name = Bytecodes::name(code);
1024 }
1025 tty->print(" - %s", code_name);
1026 tty->print_cr(" @ bci %d ", bci);
1027 if (Verbose) {
1028 vf->print();
1029 tty->cr();
1030 }
1031 }
1032 }
1033 #endif
1035 // Register map for next frame (used for stack crawl). We capture
1036 // the state of the deopt'ing frame's caller. Thus if we need to
1037 // stuff a C2I adapter we can properly fill in the callee-save
1038 // register locations.
1039 frame caller = fr.sender(reg_map);
1040 int frame_size = caller.sp() - fr.sp();
1042 frame sender = caller;
1044 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1045 // the vframeArray containing the unpacking information is allocated in the C heap.
1046 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1047 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1049 // Compare the vframeArray to the collected vframes
1050 assert(array->structural_compare(thread, chunk), "just checking");
1052 #ifndef PRODUCT
1053 if (TraceDeoptimization) {
1054 ttyLocker ttyl;
1055 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1056 }
1057 #endif // PRODUCT
1059 return array;
1060 }
1063 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1064 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1065 for (int i = 0; i < monitors->length(); i++) {
1066 MonitorInfo* mon_info = monitors->at(i);
1067 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1068 objects_to_revoke->append(Handle(mon_info->owner()));
1069 }
1070 }
1071 }
1074 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1075 if (!UseBiasedLocking) {
1076 return;
1077 }
1079 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1081 // Unfortunately we don't have a RegisterMap available in most of
1082 // the places we want to call this routine so we need to walk the
1083 // stack again to update the register map.
1084 if (map == NULL || !map->update_map()) {
1085 StackFrameStream sfs(thread, true);
1086 bool found = false;
1087 while (!found && !sfs.is_done()) {
1088 frame* cur = sfs.current();
1089 sfs.next();
1090 found = cur->id() == fr.id();
1091 }
1092 assert(found, "frame to be deoptimized not found on target thread's stack");
1093 map = sfs.register_map();
1094 }
1096 vframe* vf = vframe::new_vframe(&fr, map, thread);
1097 compiledVFrame* cvf = compiledVFrame::cast(vf);
1098 // Revoke monitors' biases in all scopes
1099 while (!cvf->is_top()) {
1100 collect_monitors(cvf, objects_to_revoke);
1101 cvf = compiledVFrame::cast(cvf->sender());
1102 }
1103 collect_monitors(cvf, objects_to_revoke);
1105 if (SafepointSynchronize::is_at_safepoint()) {
1106 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1107 } else {
1108 BiasedLocking::revoke(objects_to_revoke);
1109 }
1110 }
1113 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1114 if (!UseBiasedLocking) {
1115 return;
1116 }
1118 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1119 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1120 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1121 if (jt->has_last_Java_frame()) {
1122 StackFrameStream sfs(jt, true);
1123 while (!sfs.is_done()) {
1124 frame* cur = sfs.current();
1125 if (cb->contains(cur->pc())) {
1126 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1127 compiledVFrame* cvf = compiledVFrame::cast(vf);
1128 // Revoke monitors' biases in all scopes
1129 while (!cvf->is_top()) {
1130 collect_monitors(cvf, objects_to_revoke);
1131 cvf = compiledVFrame::cast(cvf->sender());
1132 }
1133 collect_monitors(cvf, objects_to_revoke);
1134 }
1135 sfs.next();
1136 }
1137 }
1138 }
1139 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1140 }
1143 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1144 assert(fr.can_be_deoptimized(), "checking frame type");
1146 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1148 // Patch the nmethod so that when execution returns to it we will
1149 // deopt the execution state and return to the interpreter.
1150 fr.deoptimize(thread);
1151 }
1153 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1154 // Deoptimize only if the frame comes from compile code.
1155 // Do not deoptimize the frame which is already patched
1156 // during the execution of the loops below.
1157 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1158 return;
1159 }
1160 ResourceMark rm;
1161 DeoptimizationMarker dm;
1162 if (UseBiasedLocking) {
1163 revoke_biases_of_monitors(thread, fr, map);
1164 }
1165 deoptimize_single_frame(thread, fr);
1167 }
1170 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1171 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1172 "can only deoptimize other thread at a safepoint");
1173 // Compute frame and register map based on thread and sp.
1174 RegisterMap reg_map(thread, UseBiasedLocking);
1175 frame fr = thread->last_frame();
1176 while (fr.id() != id) {
1177 fr = fr.sender(®_map);
1178 }
1179 deoptimize(thread, fr, ®_map);
1180 }
1183 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1184 if (thread == Thread::current()) {
1185 Deoptimization::deoptimize_frame_internal(thread, id);
1186 } else {
1187 VM_DeoptimizeFrame deopt(thread, id);
1188 VMThread::execute(&deopt);
1189 }
1190 }
1193 // JVMTI PopFrame support
1194 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1195 {
1196 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1197 }
1198 JRT_END
1201 #if defined(COMPILER2) || defined(SHARK)
1202 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1203 // in case of an unresolved klass entry, load the class.
1204 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1205 Klass* tk = constant_pool->klass_at(index, CHECK);
1206 return;
1207 }
1209 if (!constant_pool->tag_at(index).is_symbol()) return;
1211 Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1212 Symbol* symbol = constant_pool->symbol_at(index);
1214 // class name?
1215 if (symbol->byte_at(0) != '(') {
1216 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1217 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1218 return;
1219 }
1221 // then it must be a signature!
1222 ResourceMark rm(THREAD);
1223 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1224 if (ss.is_object()) {
1225 Symbol* class_name = ss.as_symbol(CHECK);
1226 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1227 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1228 }
1229 }
1230 }
1233 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1234 EXCEPTION_MARK;
1235 load_class_by_index(constant_pool, index, THREAD);
1236 if (HAS_PENDING_EXCEPTION) {
1237 // Exception happened during classloading. We ignore the exception here, since it
1238 // is going to be rethrown since the current activation is going to be deoptimized and
1239 // the interpreter will re-execute the bytecode.
1240 CLEAR_PENDING_EXCEPTION;
1241 // Class loading called java code which may have caused a stack
1242 // overflow. If the exception was thrown right before the return
1243 // to the runtime the stack is no longer guarded. Reguard the
1244 // stack otherwise if we return to the uncommon trap blob and the
1245 // stack bang causes a stack overflow we crash.
1246 assert(THREAD->is_Java_thread(), "only a java thread can be here");
1247 JavaThread* thread = (JavaThread*)THREAD;
1248 bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1249 if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1250 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1251 }
1252 }
1254 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1255 HandleMark hm;
1257 // uncommon_trap() is called at the beginning of the uncommon trap
1258 // handler. Note this fact before we start generating temporary frames
1259 // that can confuse an asynchronous stack walker. This counter is
1260 // decremented at the end of unpack_frames().
1261 thread->inc_in_deopt_handler();
1263 // We need to update the map if we have biased locking.
1264 RegisterMap reg_map(thread, UseBiasedLocking);
1265 frame stub_frame = thread->last_frame();
1266 frame fr = stub_frame.sender(®_map);
1267 // Make sure the calling nmethod is not getting deoptimized and removed
1268 // before we are done with it.
1269 nmethodLocker nl(fr.pc());
1271 // Log a message
1272 Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1273 trap_request, fr.pc());
1275 {
1276 ResourceMark rm;
1278 // Revoke biases of any monitors in the frame to ensure we can migrate them
1279 revoke_biases_of_monitors(thread, fr, ®_map);
1281 DeoptReason reason = trap_request_reason(trap_request);
1282 DeoptAction action = trap_request_action(trap_request);
1283 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1285 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1286 compiledVFrame* cvf = compiledVFrame::cast(vf);
1288 nmethod* nm = cvf->code();
1290 ScopeDesc* trap_scope = cvf->scope();
1291 methodHandle trap_method = trap_scope->method();
1292 int trap_bci = trap_scope->bci();
1293 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1295 // Record this event in the histogram.
1296 gather_statistics(reason, action, trap_bc);
1298 // Ensure that we can record deopt. history:
1299 // Need MDO to record RTM code generation state.
1300 bool create_if_missing = ProfileTraps RTM_OPT_ONLY( || UseRTMLocking );
1302 MethodData* trap_mdo =
1303 get_method_data(thread, trap_method, create_if_missing);
1305 // Log a message
1306 Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1307 trap_reason_name(reason), trap_action_name(action), fr.pc(),
1308 trap_method->name_and_sig_as_C_string(), trap_bci);
1310 // Print a bunch of diagnostics, if requested.
1311 if (TraceDeoptimization || LogCompilation) {
1312 ResourceMark rm;
1313 ttyLocker ttyl;
1314 char buf[100];
1315 if (xtty != NULL) {
1316 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1317 os::current_thread_id(),
1318 format_trap_request(buf, sizeof(buf), trap_request));
1319 nm->log_identity(xtty);
1320 }
1321 Symbol* class_name = NULL;
1322 bool unresolved = false;
1323 if (unloaded_class_index >= 0) {
1324 constantPoolHandle constants (THREAD, trap_method->constants());
1325 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1326 class_name = constants->klass_name_at(unloaded_class_index);
1327 unresolved = true;
1328 if (xtty != NULL)
1329 xtty->print(" unresolved='1'");
1330 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1331 class_name = constants->symbol_at(unloaded_class_index);
1332 }
1333 if (xtty != NULL)
1334 xtty->name(class_name);
1335 }
1336 if (xtty != NULL && trap_mdo != NULL) {
1337 // Dump the relevant MDO state.
1338 // This is the deopt count for the current reason, any previous
1339 // reasons or recompiles seen at this point.
1340 int dcnt = trap_mdo->trap_count(reason);
1341 if (dcnt != 0)
1342 xtty->print(" count='%d'", dcnt);
1343 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1344 int dos = (pdata == NULL)? 0: pdata->trap_state();
1345 if (dos != 0) {
1346 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1347 if (trap_state_is_recompiled(dos)) {
1348 int recnt2 = trap_mdo->overflow_recompile_count();
1349 if (recnt2 != 0)
1350 xtty->print(" recompiles2='%d'", recnt2);
1351 }
1352 }
1353 }
1354 if (xtty != NULL) {
1355 xtty->stamp();
1356 xtty->end_head();
1357 }
1358 if (TraceDeoptimization) { // make noise on the tty
1359 tty->print("Uncommon trap occurred in");
1360 nm->method()->print_short_name(tty);
1361 tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1362 fr.pc(),
1363 os::current_thread_id(),
1364 trap_reason_name(reason),
1365 trap_action_name(action),
1366 unloaded_class_index);
1367 if (class_name != NULL) {
1368 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1369 class_name->print_symbol_on(tty);
1370 }
1371 tty->cr();
1372 }
1373 if (xtty != NULL) {
1374 // Log the precise location of the trap.
1375 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1376 xtty->begin_elem("jvms bci='%d'", sd->bci());
1377 xtty->method(sd->method());
1378 xtty->end_elem();
1379 if (sd->is_top()) break;
1380 }
1381 xtty->tail("uncommon_trap");
1382 }
1383 }
1384 // (End diagnostic printout.)
1386 // Load class if necessary
1387 if (unloaded_class_index >= 0) {
1388 constantPoolHandle constants(THREAD, trap_method->constants());
1389 load_class_by_index(constants, unloaded_class_index);
1390 }
1392 // Flush the nmethod if necessary and desirable.
1393 //
1394 // We need to avoid situations where we are re-flushing the nmethod
1395 // because of a hot deoptimization site. Repeated flushes at the same
1396 // point need to be detected by the compiler and avoided. If the compiler
1397 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1398 // module must take measures to avoid an infinite cycle of recompilation
1399 // and deoptimization. There are several such measures:
1400 //
1401 // 1. If a recompilation is ordered a second time at some site X
1402 // and for the same reason R, the action is adjusted to 'reinterpret',
1403 // to give the interpreter time to exercise the method more thoroughly.
1404 // If this happens, the method's overflow_recompile_count is incremented.
1405 //
1406 // 2. If the compiler fails to reduce the deoptimization rate, then
1407 // the method's overflow_recompile_count will begin to exceed the set
1408 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1409 // is adjusted to 'make_not_compilable', and the method is abandoned
1410 // to the interpreter. This is a performance hit for hot methods,
1411 // but is better than a disastrous infinite cycle of recompilations.
1412 // (Actually, only the method containing the site X is abandoned.)
1413 //
1414 // 3. In parallel with the previous measures, if the total number of
1415 // recompilations of a method exceeds the much larger set limit
1416 // PerMethodRecompilationCutoff, the method is abandoned.
1417 // This should only happen if the method is very large and has
1418 // many "lukewarm" deoptimizations. The code which enforces this
1419 // limit is elsewhere (class nmethod, class Method).
1420 //
1421 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1422 // to recompile at each bytecode independently of the per-BCI cutoff.
1423 //
1424 // The decision to update code is up to the compiler, and is encoded
1425 // in the Action_xxx code. If the compiler requests Action_none
1426 // no trap state is changed, no compiled code is changed, and the
1427 // computation suffers along in the interpreter.
1428 //
1429 // The other action codes specify various tactics for decompilation
1430 // and recompilation. Action_maybe_recompile is the loosest, and
1431 // allows the compiled code to stay around until enough traps are seen,
1432 // and until the compiler gets around to recompiling the trapping method.
1433 //
1434 // The other actions cause immediate removal of the present code.
1436 bool update_trap_state = true;
1437 bool make_not_entrant = false;
1438 bool make_not_compilable = false;
1439 bool reprofile = false;
1440 switch (action) {
1441 case Action_none:
1442 // Keep the old code.
1443 update_trap_state = false;
1444 break;
1445 case Action_maybe_recompile:
1446 // Do not need to invalidate the present code, but we can
1447 // initiate another
1448 // Start compiler without (necessarily) invalidating the nmethod.
1449 // The system will tolerate the old code, but new code should be
1450 // generated when possible.
1451 break;
1452 case Action_reinterpret:
1453 // Go back into the interpreter for a while, and then consider
1454 // recompiling form scratch.
1455 make_not_entrant = true;
1456 // Reset invocation counter for outer most method.
1457 // This will allow the interpreter to exercise the bytecodes
1458 // for a while before recompiling.
1459 // By contrast, Action_make_not_entrant is immediate.
1460 //
1461 // Note that the compiler will track null_check, null_assert,
1462 // range_check, and class_check events and log them as if they
1463 // had been traps taken from compiled code. This will update
1464 // the MDO trap history so that the next compilation will
1465 // properly detect hot trap sites.
1466 reprofile = true;
1467 break;
1468 case Action_make_not_entrant:
1469 // Request immediate recompilation, and get rid of the old code.
1470 // Make them not entrant, so next time they are called they get
1471 // recompiled. Unloaded classes are loaded now so recompile before next
1472 // time they are called. Same for uninitialized. The interpreter will
1473 // link the missing class, if any.
1474 make_not_entrant = true;
1475 break;
1476 case Action_make_not_compilable:
1477 // Give up on compiling this method at all.
1478 make_not_entrant = true;
1479 make_not_compilable = true;
1480 break;
1481 default:
1482 ShouldNotReachHere();
1483 }
1485 // Setting +ProfileTraps fixes the following, on all platforms:
1486 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1487 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1488 // recompile relies on a MethodData* to record heroic opt failures.
1490 // Whether the interpreter is producing MDO data or not, we also need
1491 // to use the MDO to detect hot deoptimization points and control
1492 // aggressive optimization.
1493 bool inc_recompile_count = false;
1494 ProfileData* pdata = NULL;
1495 if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1496 assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1497 uint this_trap_count = 0;
1498 bool maybe_prior_trap = false;
1499 bool maybe_prior_recompile = false;
1500 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1501 nm->method(),
1502 //outputs:
1503 this_trap_count,
1504 maybe_prior_trap,
1505 maybe_prior_recompile);
1506 // Because the interpreter also counts null, div0, range, and class
1507 // checks, these traps from compiled code are double-counted.
1508 // This is harmless; it just means that the PerXTrapLimit values
1509 // are in effect a little smaller than they look.
1511 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1512 if (per_bc_reason != Reason_none) {
1513 // Now take action based on the partially known per-BCI history.
1514 if (maybe_prior_trap
1515 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1516 // If there are too many traps at this BCI, force a recompile.
1517 // This will allow the compiler to see the limit overflow, and
1518 // take corrective action, if possible. The compiler generally
1519 // does not use the exact PerBytecodeTrapLimit value, but instead
1520 // changes its tactics if it sees any traps at all. This provides
1521 // a little hysteresis, delaying a recompile until a trap happens
1522 // several times.
1523 //
1524 // Actually, since there is only one bit of counter per BCI,
1525 // the possible per-BCI counts are {0,1,(per-method count)}.
1526 // This produces accurate results if in fact there is only
1527 // one hot trap site, but begins to get fuzzy if there are
1528 // many sites. For example, if there are ten sites each
1529 // trapping two or more times, they each get the blame for
1530 // all of their traps.
1531 make_not_entrant = true;
1532 }
1534 // Detect repeated recompilation at the same BCI, and enforce a limit.
1535 if (make_not_entrant && maybe_prior_recompile) {
1536 // More than one recompile at this point.
1537 inc_recompile_count = maybe_prior_trap;
1538 }
1539 } else {
1540 // For reasons which are not recorded per-bytecode, we simply
1541 // force recompiles unconditionally.
1542 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1543 make_not_entrant = true;
1544 }
1546 // Go back to the compiler if there are too many traps in this method.
1547 if (this_trap_count >= per_method_trap_limit(reason)) {
1548 // If there are too many traps in this method, force a recompile.
1549 // This will allow the compiler to see the limit overflow, and
1550 // take corrective action, if possible.
1551 // (This condition is an unlikely backstop only, because the
1552 // PerBytecodeTrapLimit is more likely to take effect first,
1553 // if it is applicable.)
1554 make_not_entrant = true;
1555 }
1557 // Here's more hysteresis: If there has been a recompile at
1558 // this trap point already, run the method in the interpreter
1559 // for a while to exercise it more thoroughly.
1560 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1561 reprofile = true;
1562 }
1564 }
1566 // Take requested actions on the method:
1568 // Recompile
1569 if (make_not_entrant) {
1570 if (!nm->make_not_entrant()) {
1571 return; // the call did not change nmethod's state
1572 }
1574 if (pdata != NULL) {
1575 // Record the recompilation event, if any.
1576 int tstate0 = pdata->trap_state();
1577 int tstate1 = trap_state_set_recompiled(tstate0, true);
1578 if (tstate1 != tstate0)
1579 pdata->set_trap_state(tstate1);
1580 }
1582 #if INCLUDE_RTM_OPT
1583 // Restart collecting RTM locking abort statistic if the method
1584 // is recompiled for a reason other than RTM state change.
1585 // Assume that in new recompiled code the statistic could be different,
1586 // for example, due to different inlining.
1587 if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1588 UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1589 trap_mdo->atomic_set_rtm_state(ProfileRTM);
1590 }
1591 #endif
1592 }
1594 if (inc_recompile_count) {
1595 trap_mdo->inc_overflow_recompile_count();
1596 if ((uint)trap_mdo->overflow_recompile_count() >
1597 (uint)PerBytecodeRecompilationCutoff) {
1598 // Give up on the method containing the bad BCI.
1599 if (trap_method() == nm->method()) {
1600 make_not_compilable = true;
1601 } else {
1602 trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1603 // But give grace to the enclosing nm->method().
1604 }
1605 }
1606 }
1608 // Reprofile
1609 if (reprofile) {
1610 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1611 }
1613 // Give up compiling
1614 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1615 assert(make_not_entrant, "consistent");
1616 nm->method()->set_not_compilable(CompLevel_full_optimization);
1617 }
1619 } // Free marked resources
1621 }
1622 JRT_END
1624 MethodData*
1625 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1626 bool create_if_missing) {
1627 Thread* THREAD = thread;
1628 MethodData* mdo = m()->method_data();
1629 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1630 // Build an MDO. Ignore errors like OutOfMemory;
1631 // that simply means we won't have an MDO to update.
1632 Method::build_interpreter_method_data(m, THREAD);
1633 if (HAS_PENDING_EXCEPTION) {
1634 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1635 CLEAR_PENDING_EXCEPTION;
1636 }
1637 mdo = m()->method_data();
1638 }
1639 return mdo;
1640 }
1642 ProfileData*
1643 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1644 int trap_bci,
1645 Deoptimization::DeoptReason reason,
1646 Method* compiled_method,
1647 //outputs:
1648 uint& ret_this_trap_count,
1649 bool& ret_maybe_prior_trap,
1650 bool& ret_maybe_prior_recompile) {
1651 uint prior_trap_count = trap_mdo->trap_count(reason);
1652 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1654 // If the runtime cannot find a place to store trap history,
1655 // it is estimated based on the general condition of the method.
1656 // If the method has ever been recompiled, or has ever incurred
1657 // a trap with the present reason , then this BCI is assumed
1658 // (pessimistically) to be the culprit.
1659 bool maybe_prior_trap = (prior_trap_count != 0);
1660 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1661 ProfileData* pdata = NULL;
1664 // For reasons which are recorded per bytecode, we check per-BCI data.
1665 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1666 if (per_bc_reason != Reason_none) {
1667 // Find the profile data for this BCI. If there isn't one,
1668 // try to allocate one from the MDO's set of spares.
1669 // This will let us detect a repeated trap at this point.
1670 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1672 if (pdata != NULL) {
1673 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1674 if (LogCompilation && xtty != NULL) {
1675 ttyLocker ttyl;
1676 // no more room for speculative traps in this MDO
1677 xtty->elem("speculative_traps_oom");
1678 }
1679 }
1680 // Query the trap state of this profile datum.
1681 int tstate0 = pdata->trap_state();
1682 if (!trap_state_has_reason(tstate0, per_bc_reason))
1683 maybe_prior_trap = false;
1684 if (!trap_state_is_recompiled(tstate0))
1685 maybe_prior_recompile = false;
1687 // Update the trap state of this profile datum.
1688 int tstate1 = tstate0;
1689 // Record the reason.
1690 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1691 // Store the updated state on the MDO, for next time.
1692 if (tstate1 != tstate0)
1693 pdata->set_trap_state(tstate1);
1694 } else {
1695 if (LogCompilation && xtty != NULL) {
1696 ttyLocker ttyl;
1697 // Missing MDP? Leave a small complaint in the log.
1698 xtty->elem("missing_mdp bci='%d'", trap_bci);
1699 }
1700 }
1701 }
1703 // Return results:
1704 ret_this_trap_count = this_trap_count;
1705 ret_maybe_prior_trap = maybe_prior_trap;
1706 ret_maybe_prior_recompile = maybe_prior_recompile;
1707 return pdata;
1708 }
1710 void
1711 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1712 ResourceMark rm;
1713 // Ignored outputs:
1714 uint ignore_this_trap_count;
1715 bool ignore_maybe_prior_trap;
1716 bool ignore_maybe_prior_recompile;
1717 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1718 query_update_method_data(trap_mdo, trap_bci,
1719 (DeoptReason)reason,
1720 NULL,
1721 ignore_this_trap_count,
1722 ignore_maybe_prior_trap,
1723 ignore_maybe_prior_recompile);
1724 }
1726 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1728 // Still in Java no safepoints
1729 {
1730 // This enters VM and may safepoint
1731 uncommon_trap_inner(thread, trap_request);
1732 }
1733 return fetch_unroll_info_helper(thread);
1734 }
1736 // Local derived constants.
1737 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1738 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1739 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1741 //---------------------------trap_state_reason---------------------------------
1742 Deoptimization::DeoptReason
1743 Deoptimization::trap_state_reason(int trap_state) {
1744 // This assert provides the link between the width of DataLayout::trap_bits
1745 // and the encoding of "recorded" reasons. It ensures there are enough
1746 // bits to store all needed reasons in the per-BCI MDO profile.
1747 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1748 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1749 trap_state -= recompile_bit;
1750 if (trap_state == DS_REASON_MASK) {
1751 return Reason_many;
1752 } else {
1753 assert((int)Reason_none == 0, "state=0 => Reason_none");
1754 return (DeoptReason)trap_state;
1755 }
1756 }
1757 //-------------------------trap_state_has_reason-------------------------------
1758 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1759 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1760 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1761 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1762 trap_state -= recompile_bit;
1763 if (trap_state == DS_REASON_MASK) {
1764 return -1; // true, unspecifically (bottom of state lattice)
1765 } else if (trap_state == reason) {
1766 return 1; // true, definitely
1767 } else if (trap_state == 0) {
1768 return 0; // false, definitely (top of state lattice)
1769 } else {
1770 return 0; // false, definitely
1771 }
1772 }
1773 //-------------------------trap_state_add_reason-------------------------------
1774 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1775 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1776 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1777 trap_state -= recompile_bit;
1778 if (trap_state == DS_REASON_MASK) {
1779 return trap_state + recompile_bit; // already at state lattice bottom
1780 } else if (trap_state == reason) {
1781 return trap_state + recompile_bit; // the condition is already true
1782 } else if (trap_state == 0) {
1783 return reason + recompile_bit; // no condition has yet been true
1784 } else {
1785 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1786 }
1787 }
1788 //-----------------------trap_state_is_recompiled------------------------------
1789 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1790 return (trap_state & DS_RECOMPILE_BIT) != 0;
1791 }
1792 //-----------------------trap_state_set_recompiled-----------------------------
1793 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1794 if (z) return trap_state | DS_RECOMPILE_BIT;
1795 else return trap_state & ~DS_RECOMPILE_BIT;
1796 }
1797 //---------------------------format_trap_state---------------------------------
1798 // This is used for debugging and diagnostics, including LogFile output.
1799 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1800 int trap_state) {
1801 DeoptReason reason = trap_state_reason(trap_state);
1802 bool recomp_flag = trap_state_is_recompiled(trap_state);
1803 // Re-encode the state from its decoded components.
1804 int decoded_state = 0;
1805 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1806 decoded_state = trap_state_add_reason(decoded_state, reason);
1807 if (recomp_flag)
1808 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1809 // If the state re-encodes properly, format it symbolically.
1810 // Because this routine is used for debugging and diagnostics,
1811 // be robust even if the state is a strange value.
1812 size_t len;
1813 if (decoded_state != trap_state) {
1814 // Random buggy state that doesn't decode??
1815 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1816 } else {
1817 len = jio_snprintf(buf, buflen, "%s%s",
1818 trap_reason_name(reason),
1819 recomp_flag ? " recompiled" : "");
1820 }
1821 if (len >= buflen)
1822 buf[buflen-1] = '\0';
1823 return buf;
1824 }
1827 //--------------------------------statics--------------------------------------
1828 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1829 = Deoptimization::Action_reinterpret;
1830 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1831 // Note: Keep this in sync. with enum DeoptReason.
1832 "none",
1833 "null_check",
1834 "null_assert",
1835 "range_check",
1836 "class_check",
1837 "array_check",
1838 "intrinsic",
1839 "bimorphic",
1840 "unloaded",
1841 "uninitialized",
1842 "unreached",
1843 "unhandled",
1844 "constraint",
1845 "div0_check",
1846 "age",
1847 "predicate",
1848 "loop_limit_check",
1849 "speculate_class_check",
1850 "rtm_state_change"
1851 };
1852 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1853 // Note: Keep this in sync. with enum DeoptAction.
1854 "none",
1855 "maybe_recompile",
1856 "reinterpret",
1857 "make_not_entrant",
1858 "make_not_compilable"
1859 };
1861 const char* Deoptimization::trap_reason_name(int reason) {
1862 if (reason == Reason_many) return "many";
1863 if ((uint)reason < Reason_LIMIT)
1864 return _trap_reason_name[reason];
1865 static char buf[20];
1866 sprintf(buf, "reason%d", reason);
1867 return buf;
1868 }
1869 const char* Deoptimization::trap_action_name(int action) {
1870 if ((uint)action < Action_LIMIT)
1871 return _trap_action_name[action];
1872 static char buf[20];
1873 sprintf(buf, "action%d", action);
1874 return buf;
1875 }
1877 // This is used for debugging and diagnostics, including LogFile output.
1878 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1879 int trap_request) {
1880 jint unloaded_class_index = trap_request_index(trap_request);
1881 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1882 const char* action = trap_action_name(trap_request_action(trap_request));
1883 size_t len;
1884 if (unloaded_class_index < 0) {
1885 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1886 reason, action);
1887 } else {
1888 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1889 reason, action, unloaded_class_index);
1890 }
1891 if (len >= buflen)
1892 buf[buflen-1] = '\0';
1893 return buf;
1894 }
1896 juint Deoptimization::_deoptimization_hist
1897 [Deoptimization::Reason_LIMIT]
1898 [1 + Deoptimization::Action_LIMIT]
1899 [Deoptimization::BC_CASE_LIMIT]
1900 = {0};
1902 enum {
1903 LSB_BITS = 8,
1904 LSB_MASK = right_n_bits(LSB_BITS)
1905 };
1907 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1908 Bytecodes::Code bc) {
1909 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1910 assert(action >= 0 && action < Action_LIMIT, "oob");
1911 _deoptimization_hist[Reason_none][0][0] += 1; // total
1912 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1913 juint* cases = _deoptimization_hist[reason][1+action];
1914 juint* bc_counter_addr = NULL;
1915 juint bc_counter = 0;
1916 // Look for an unused counter, or an exact match to this BC.
1917 if (bc != Bytecodes::_illegal) {
1918 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1919 juint* counter_addr = &cases[bc_case];
1920 juint counter = *counter_addr;
1921 if ((counter == 0 && bc_counter_addr == NULL)
1922 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1923 // this counter is either free or is already devoted to this BC
1924 bc_counter_addr = counter_addr;
1925 bc_counter = counter | bc;
1926 }
1927 }
1928 }
1929 if (bc_counter_addr == NULL) {
1930 // Overflow, or no given bytecode.
1931 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1932 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1933 }
1934 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1935 }
1937 jint Deoptimization::total_deoptimization_count() {
1938 return _deoptimization_hist[Reason_none][0][0];
1939 }
1941 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1942 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1943 return _deoptimization_hist[reason][0][0];
1944 }
1946 void Deoptimization::print_statistics() {
1947 juint total = total_deoptimization_count();
1948 juint account = total;
1949 if (total != 0) {
1950 ttyLocker ttyl;
1951 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1952 tty->print_cr("Deoptimization traps recorded:");
1953 #define PRINT_STAT_LINE(name, r) \
1954 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1955 PRINT_STAT_LINE("total", total);
1956 // For each non-zero entry in the histogram, print the reason,
1957 // the action, and (if specifically known) the type of bytecode.
1958 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1959 for (int action = 0; action < Action_LIMIT; action++) {
1960 juint* cases = _deoptimization_hist[reason][1+action];
1961 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1962 juint counter = cases[bc_case];
1963 if (counter != 0) {
1964 char name[1*K];
1965 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1966 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1967 bc = Bytecodes::_illegal;
1968 sprintf(name, "%s/%s/%s",
1969 trap_reason_name(reason),
1970 trap_action_name(action),
1971 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1972 juint r = counter >> LSB_BITS;
1973 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1974 account -= r;
1975 }
1976 }
1977 }
1978 }
1979 if (account != 0) {
1980 PRINT_STAT_LINE("unaccounted", account);
1981 }
1982 #undef PRINT_STAT_LINE
1983 if (xtty != NULL) xtty->tail("statistics");
1984 }
1985 }
1986 #else // COMPILER2 || SHARK
1989 // Stubs for C1 only system.
1990 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1991 return false;
1992 }
1994 const char* Deoptimization::trap_reason_name(int reason) {
1995 return "unknown";
1996 }
1998 void Deoptimization::print_statistics() {
1999 // no output
2000 }
2002 void
2003 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2004 // no udpate
2005 }
2007 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2008 return 0;
2009 }
2011 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2012 Bytecodes::Code bc) {
2013 // no update
2014 }
2016 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2017 int trap_state) {
2018 jio_snprintf(buf, buflen, "#%d", trap_state);
2019 return buf;
2020 }
2022 #endif // COMPILER2 || SHARK