Fri, 31 Oct 2014 12:16:20 +0100
8062169: Multiple OSR compilations issued for same bci
Summary: Fixed 'SimpleThresholdPolicy::event' to always perform OSR if an OSR nmethod is available.
Reviewed-by: kvn, iveresov
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.
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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/method.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef TARGET_ARCH_arm
63 # include "vmreg_arm.inline.hpp"
64 #endif
65 #ifdef TARGET_ARCH_ppc
66 # include "vmreg_ppc.inline.hpp"
67 #endif
68 #ifdef COMPILER2
69 #ifdef TARGET_ARCH_MODEL_x86_32
70 # include "adfiles/ad_x86_32.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_x86_64
73 # include "adfiles/ad_x86_64.hpp"
74 #endif
75 #ifdef TARGET_ARCH_MODEL_sparc
76 # include "adfiles/ad_sparc.hpp"
77 #endif
78 #ifdef TARGET_ARCH_MODEL_zero
79 # include "adfiles/ad_zero.hpp"
80 #endif
81 #ifdef TARGET_ARCH_MODEL_arm
82 # include "adfiles/ad_arm.hpp"
83 #endif
84 #ifdef TARGET_ARCH_MODEL_ppc_32
85 # include "adfiles/ad_ppc_32.hpp"
86 #endif
87 #ifdef TARGET_ARCH_MODEL_ppc_64
88 # include "adfiles/ad_ppc_64.hpp"
89 #endif
90 #endif // COMPILER2
92 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
94 bool DeoptimizationMarker::_is_active = false;
96 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
97 int caller_adjustment,
98 int caller_actual_parameters,
99 int number_of_frames,
100 intptr_t* frame_sizes,
101 address* frame_pcs,
102 BasicType return_type) {
103 _size_of_deoptimized_frame = size_of_deoptimized_frame;
104 _caller_adjustment = caller_adjustment;
105 _caller_actual_parameters = caller_actual_parameters;
106 _number_of_frames = number_of_frames;
107 _frame_sizes = frame_sizes;
108 _frame_pcs = frame_pcs;
109 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
110 _return_type = return_type;
111 _initial_info = 0;
112 // PD (x86 only)
113 _counter_temp = 0;
114 _unpack_kind = 0;
115 _sender_sp_temp = 0;
117 _total_frame_sizes = size_of_frames();
118 }
121 Deoptimization::UnrollBlock::~UnrollBlock() {
122 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
123 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
124 FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
125 }
128 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
129 assert(register_number < RegisterMap::reg_count, "checking register number");
130 return &_register_block[register_number * 2];
131 }
135 int Deoptimization::UnrollBlock::size_of_frames() const {
136 // Acount first for the adjustment of the initial frame
137 int result = _caller_adjustment;
138 for (int index = 0; index < number_of_frames(); index++) {
139 result += frame_sizes()[index];
140 }
141 return result;
142 }
145 void Deoptimization::UnrollBlock::print() {
146 ttyLocker ttyl;
147 tty->print_cr("UnrollBlock");
148 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
149 tty->print( " frame_sizes: ");
150 for (int index = 0; index < number_of_frames(); index++) {
151 tty->print("%d ", frame_sizes()[index]);
152 }
153 tty->cr();
154 }
157 // In order to make fetch_unroll_info work properly with escape
158 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
159 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
160 // of previously eliminated objects occurs in realloc_objects, which is
161 // called from the method fetch_unroll_info_helper below.
162 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
163 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
164 // but makes the entry a little slower. There is however a little dance we have to
165 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
167 // fetch_unroll_info() is called at the beginning of the deoptimization
168 // handler. Note this fact before we start generating temporary frames
169 // that can confuse an asynchronous stack walker. This counter is
170 // decremented at the end of unpack_frames().
171 thread->inc_in_deopt_handler();
173 return fetch_unroll_info_helper(thread);
174 JRT_END
177 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
178 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
180 // Note: there is a safepoint safety issue here. No matter whether we enter
181 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
182 // the vframeArray is created.
183 //
185 // Allocate our special deoptimization ResourceMark
186 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
187 assert(thread->deopt_mark() == NULL, "Pending deopt!");
188 thread->set_deopt_mark(dmark);
190 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
191 RegisterMap map(thread, true);
192 RegisterMap dummy_map(thread, false);
193 // Now get the deoptee with a valid map
194 frame deoptee = stub_frame.sender(&map);
195 // Set the deoptee nmethod
196 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
197 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
199 if (VerifyStack) {
200 thread->validate_frame_layout();
201 }
203 // Create a growable array of VFrames where each VFrame represents an inlined
204 // Java frame. This storage is allocated with the usual system arena.
205 assert(deoptee.is_compiled_frame(), "Wrong frame type");
206 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
207 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
208 while (!vf->is_top()) {
209 assert(vf->is_compiled_frame(), "Wrong frame type");
210 chunk->push(compiledVFrame::cast(vf));
211 vf = vf->sender();
212 }
213 assert(vf->is_compiled_frame(), "Wrong frame type");
214 chunk->push(compiledVFrame::cast(vf));
216 #ifdef COMPILER2
217 // Reallocate the non-escaping objects and restore their fields. Then
218 // relock objects if synchronization on them was eliminated.
219 if (DoEscapeAnalysis || EliminateNestedLocks) {
220 if (EliminateAllocations) {
221 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
222 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
224 // The flag return_oop() indicates call sites which return oop
225 // in compiled code. Such sites include java method calls,
226 // runtime calls (for example, used to allocate new objects/arrays
227 // on slow code path) and any other calls generated in compiled code.
228 // It is not guaranteed that we can get such information here only
229 // by analyzing bytecode in deoptimized frames. This is why this flag
230 // is set during method compilation (see Compile::Process_OopMap_Node()).
231 // If the previous frame was popped, we don't have a result.
232 bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution();
233 Handle return_value;
234 if (save_oop_result) {
235 // Reallocation may trigger GC. If deoptimization happened on return from
236 // call which returns oop we need to save it since it is not in oopmap.
237 oop result = deoptee.saved_oop_result(&map);
238 assert(result == NULL || result->is_oop(), "must be oop");
239 return_value = Handle(thread, result);
240 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
241 if (TraceDeoptimization) {
242 ttyLocker ttyl;
243 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
244 }
245 }
246 bool reallocated = false;
247 if (objects != NULL) {
248 JRT_BLOCK
249 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
250 JRT_END
251 }
252 if (reallocated) {
253 reassign_fields(&deoptee, &map, objects);
254 #ifndef PRODUCT
255 if (TraceDeoptimization) {
256 ttyLocker ttyl;
257 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
258 print_objects(objects);
259 }
260 #endif
261 }
262 if (save_oop_result) {
263 // Restore result.
264 deoptee.set_saved_oop_result(&map, return_value());
265 }
266 }
267 if (EliminateLocks) {
268 #ifndef PRODUCT
269 bool first = true;
270 #endif
271 for (int i = 0; i < chunk->length(); i++) {
272 compiledVFrame* cvf = chunk->at(i);
273 assert (cvf->scope() != NULL,"expect only compiled java frames");
274 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
275 if (monitors->is_nonempty()) {
276 relock_objects(monitors, thread);
277 #ifndef PRODUCT
278 if (TraceDeoptimization) {
279 ttyLocker ttyl;
280 for (int j = 0; j < monitors->length(); j++) {
281 MonitorInfo* mi = monitors->at(j);
282 if (mi->eliminated()) {
283 if (first) {
284 first = false;
285 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
286 }
287 tty->print_cr(" object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
288 }
289 }
290 }
291 #endif
292 }
293 }
294 }
295 }
296 #endif // COMPILER2
297 // Ensure that no safepoint is taken after pointers have been stored
298 // in fields of rematerialized objects. If a safepoint occurs from here on
299 // out the java state residing in the vframeArray will be missed.
300 No_Safepoint_Verifier no_safepoint;
302 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
304 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
305 thread->set_vframe_array_head(array);
307 // Now that the vframeArray has been created if we have any deferred local writes
308 // added by jvmti then we can free up that structure as the data is now in the
309 // vframeArray
311 if (thread->deferred_locals() != NULL) {
312 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
313 int i = 0;
314 do {
315 // Because of inlining we could have multiple vframes for a single frame
316 // and several of the vframes could have deferred writes. Find them all.
317 if (list->at(i)->id() == array->original().id()) {
318 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
319 list->remove_at(i);
320 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
321 delete dlv;
322 } else {
323 i++;
324 }
325 } while ( i < list->length() );
326 if (list->length() == 0) {
327 thread->set_deferred_locals(NULL);
328 // free the list and elements back to C heap.
329 delete list;
330 }
332 }
334 #ifndef SHARK
335 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
336 CodeBlob* cb = stub_frame.cb();
337 // Verify we have the right vframeArray
338 assert(cb->frame_size() >= 0, "Unexpected frame size");
339 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
341 // If the deopt call site is a MethodHandle invoke call site we have
342 // to adjust the unpack_sp.
343 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
344 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
345 unpack_sp = deoptee.unextended_sp();
347 #ifdef ASSERT
348 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
349 #endif
350 #else
351 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
352 #endif // !SHARK
354 // This is a guarantee instead of an assert because if vframe doesn't match
355 // we will unpack the wrong deoptimized frame and wind up in strange places
356 // where it will be very difficult to figure out what went wrong. Better
357 // to die an early death here than some very obscure death later when the
358 // trail is cold.
359 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
360 // in that it will fail to detect a problem when there is one. This needs
361 // more work in tiger timeframe.
362 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
364 int number_of_frames = array->frames();
366 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
367 // virtual activation, which is the reverse of the elements in the vframes array.
368 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
369 // +1 because we always have an interpreter return address for the final slot.
370 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
371 int popframe_extra_args = 0;
372 // Create an interpreter return address for the stub to use as its return
373 // address so the skeletal frames are perfectly walkable
374 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
376 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
377 // activation be put back on the expression stack of the caller for reexecution
378 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
379 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
380 }
382 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
383 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
384 // than simply use array->sender.pc(). This requires us to walk the current set of frames
385 //
386 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
387 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
389 // It's possible that the number of paramters at the call site is
390 // different than number of arguments in the callee when method
391 // handles are used. If the caller is interpreted get the real
392 // value so that the proper amount of space can be added to it's
393 // frame.
394 bool caller_was_method_handle = false;
395 if (deopt_sender.is_interpreted_frame()) {
396 methodHandle method = deopt_sender.interpreter_frame_method();
397 Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
398 if (cur.is_invokedynamic() || cur.is_invokehandle()) {
399 // Method handle invokes may involve fairly arbitrary chains of
400 // calls so it's impossible to know how much actual space the
401 // caller has for locals.
402 caller_was_method_handle = true;
403 }
404 }
406 //
407 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
408 // frame_sizes/frame_pcs[1] next oldest frame (int)
409 // frame_sizes/frame_pcs[n] youngest frame (int)
410 //
411 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
412 // owns the space for the return address to it's caller). Confusing ain't it.
413 //
414 // The vframe array can address vframes with indices running from
415 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
416 // When we create the skeletal frames we need the oldest frame to be in the zero slot
417 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
418 // so things look a little strange in this loop.
419 //
420 int callee_parameters = 0;
421 int callee_locals = 0;
422 for (int index = 0; index < array->frames(); index++ ) {
423 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
424 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
425 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
426 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
427 callee_locals,
428 index == 0,
429 popframe_extra_args);
430 // This pc doesn't have to be perfect just good enough to identify the frame
431 // as interpreted so the skeleton frame will be walkable
432 // The correct pc will be set when the skeleton frame is completely filled out
433 // The final pc we store in the loop is wrong and will be overwritten below
434 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
436 callee_parameters = array->element(index)->method()->size_of_parameters();
437 callee_locals = array->element(index)->method()->max_locals();
438 popframe_extra_args = 0;
439 }
441 // Compute whether the root vframe returns a float or double value.
442 BasicType return_type;
443 {
444 HandleMark hm;
445 methodHandle method(thread, array->element(0)->method());
446 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
447 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
448 }
450 // Compute information for handling adapters and adjusting the frame size of the caller.
451 int caller_adjustment = 0;
453 // Compute the amount the oldest interpreter frame will have to adjust
454 // its caller's stack by. If the caller is a compiled frame then
455 // we pretend that the callee has no parameters so that the
456 // extension counts for the full amount of locals and not just
457 // locals-parms. This is because without a c2i adapter the parm
458 // area as created by the compiled frame will not be usable by
459 // the interpreter. (Depending on the calling convention there
460 // may not even be enough space).
462 // QQQ I'd rather see this pushed down into last_frame_adjust
463 // and have it take the sender (aka caller).
465 if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
466 caller_adjustment = last_frame_adjust(0, callee_locals);
467 } else if (callee_locals > callee_parameters) {
468 // The caller frame may need extending to accommodate
469 // non-parameter locals of the first unpacked interpreted frame.
470 // Compute that adjustment.
471 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
472 }
474 // If the sender is deoptimized the we must retrieve the address of the handler
475 // since the frame will "magically" show the original pc before the deopt
476 // and we'd undo the deopt.
478 frame_pcs[0] = deopt_sender.raw_pc();
480 #ifndef SHARK
481 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
482 #endif // SHARK
484 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
485 caller_adjustment * BytesPerWord,
486 caller_was_method_handle ? 0 : callee_parameters,
487 number_of_frames,
488 frame_sizes,
489 frame_pcs,
490 return_type);
491 // On some platforms, we need a way to pass some platform dependent
492 // information to the unpacking code so the skeletal frames come out
493 // correct (initial fp value, unextended sp, ...)
494 info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
496 if (array->frames() > 1) {
497 if (VerifyStack && TraceDeoptimization) {
498 ttyLocker ttyl;
499 tty->print_cr("Deoptimizing method containing inlining");
500 }
501 }
503 array->set_unroll_block(info);
504 return info;
505 }
507 // Called to cleanup deoptimization data structures in normal case
508 // after unpacking to stack and when stack overflow error occurs
509 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
510 vframeArray *array) {
512 // Get array if coming from exception
513 if (array == NULL) {
514 array = thread->vframe_array_head();
515 }
516 thread->set_vframe_array_head(NULL);
518 // Free the previous UnrollBlock
519 vframeArray* old_array = thread->vframe_array_last();
520 thread->set_vframe_array_last(array);
522 if (old_array != NULL) {
523 UnrollBlock* old_info = old_array->unroll_block();
524 old_array->set_unroll_block(NULL);
525 delete old_info;
526 delete old_array;
527 }
529 // Deallocate any resource creating in this routine and any ResourceObjs allocated
530 // inside the vframeArray (StackValueCollections)
532 delete thread->deopt_mark();
533 thread->set_deopt_mark(NULL);
534 thread->set_deopt_nmethod(NULL);
537 if (JvmtiExport::can_pop_frame()) {
538 #ifndef CC_INTERP
539 // Regardless of whether we entered this routine with the pending
540 // popframe condition bit set, we should always clear it now
541 thread->clear_popframe_condition();
542 #else
543 // C++ interpeter will clear has_pending_popframe when it enters
544 // with method_resume. For deopt_resume2 we clear it now.
545 if (thread->popframe_forcing_deopt_reexecution())
546 thread->clear_popframe_condition();
547 #endif /* CC_INTERP */
548 }
550 // unpack_frames() is called at the end of the deoptimization handler
551 // and (in C2) at the end of the uncommon trap handler. Note this fact
552 // so that an asynchronous stack walker can work again. This counter is
553 // incremented at the beginning of fetch_unroll_info() and (in C2) at
554 // the beginning of uncommon_trap().
555 thread->dec_in_deopt_handler();
556 }
559 // Return BasicType of value being returned
560 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
562 // We are already active int he special DeoptResourceMark any ResourceObj's we
563 // allocate will be freed at the end of the routine.
565 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
566 // but makes the entry a little slower. There is however a little dance we have to
567 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
568 ResetNoHandleMark rnhm; // No-op in release/product versions
569 HandleMark hm;
571 frame stub_frame = thread->last_frame();
573 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
574 // must point to the vframeArray for the unpack frame.
575 vframeArray* array = thread->vframe_array_head();
577 #ifndef PRODUCT
578 if (TraceDeoptimization) {
579 ttyLocker ttyl;
580 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
581 }
582 #endif
583 Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
584 stub_frame.pc(), stub_frame.sp(), exec_mode);
586 UnrollBlock* info = array->unroll_block();
588 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
589 array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
591 BasicType bt = info->return_type();
593 // If we have an exception pending, claim that the return type is an oop
594 // so the deopt_blob does not overwrite the exception_oop.
596 if (exec_mode == Unpack_exception)
597 bt = T_OBJECT;
599 // Cleanup thread deopt data
600 cleanup_deopt_info(thread, array);
602 #ifndef PRODUCT
603 if (VerifyStack) {
604 ResourceMark res_mark;
606 thread->validate_frame_layout();
608 // Verify that the just-unpacked frames match the interpreter's
609 // notions of expression stack and locals
610 vframeArray* cur_array = thread->vframe_array_last();
611 RegisterMap rm(thread, false);
612 rm.set_include_argument_oops(false);
613 bool is_top_frame = true;
614 int callee_size_of_parameters = 0;
615 int callee_max_locals = 0;
616 for (int i = 0; i < cur_array->frames(); i++) {
617 vframeArrayElement* el = cur_array->element(i);
618 frame* iframe = el->iframe();
619 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
621 // Get the oop map for this bci
622 InterpreterOopMap mask;
623 int cur_invoke_parameter_size = 0;
624 bool try_next_mask = false;
625 int next_mask_expression_stack_size = -1;
626 int top_frame_expression_stack_adjustment = 0;
627 methodHandle mh(thread, iframe->interpreter_frame_method());
628 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
629 BytecodeStream str(mh);
630 str.set_start(iframe->interpreter_frame_bci());
631 int max_bci = mh->code_size();
632 // Get to the next bytecode if possible
633 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
634 // Check to see if we can grab the number of outgoing arguments
635 // at an uncommon trap for an invoke (where the compiler
636 // generates debug info before the invoke has executed)
637 Bytecodes::Code cur_code = str.next();
638 if (cur_code == Bytecodes::_invokevirtual ||
639 cur_code == Bytecodes::_invokespecial ||
640 cur_code == Bytecodes::_invokestatic ||
641 cur_code == Bytecodes::_invokeinterface ||
642 cur_code == Bytecodes::_invokedynamic) {
643 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
644 Symbol* signature = invoke.signature();
645 ArgumentSizeComputer asc(signature);
646 cur_invoke_parameter_size = asc.size();
647 if (invoke.has_receiver()) {
648 // Add in receiver
649 ++cur_invoke_parameter_size;
650 }
651 if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
652 callee_size_of_parameters++;
653 }
654 }
655 if (str.bci() < max_bci) {
656 Bytecodes::Code bc = str.next();
657 if (bc >= 0) {
658 // The interpreter oop map generator reports results before
659 // the current bytecode has executed except in the case of
660 // calls. It seems to be hard to tell whether the compiler
661 // has emitted debug information matching the "state before"
662 // a given bytecode or the state after, so we try both
663 switch (cur_code) {
664 case Bytecodes::_invokevirtual:
665 case Bytecodes::_invokespecial:
666 case Bytecodes::_invokestatic:
667 case Bytecodes::_invokeinterface:
668 case Bytecodes::_invokedynamic:
669 case Bytecodes::_athrow:
670 break;
671 default: {
672 InterpreterOopMap next_mask;
673 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
674 next_mask_expression_stack_size = next_mask.expression_stack_size();
675 // Need to subtract off the size of the result type of
676 // the bytecode because this is not described in the
677 // debug info but returned to the interpreter in the TOS
678 // caching register
679 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
680 if (bytecode_result_type != T_ILLEGAL) {
681 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
682 }
683 assert(top_frame_expression_stack_adjustment >= 0, "");
684 try_next_mask = true;
685 break;
686 }
687 }
688 }
689 }
691 // Verify stack depth and oops in frame
692 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
693 if (!(
694 /* SPARC */
695 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
696 /* x86 */
697 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
698 (try_next_mask &&
699 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
700 top_frame_expression_stack_adjustment))) ||
701 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
702 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
703 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
704 )) {
705 ttyLocker ttyl;
707 // Print out some information that will help us debug the problem
708 tty->print_cr("Wrong number of expression stack elements during deoptimization");
709 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
710 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
711 iframe->interpreter_frame_expression_stack_size());
712 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
713 tty->print_cr(" try_next_mask = %d", try_next_mask);
714 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
715 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
716 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
717 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
718 tty->print_cr(" exec_mode = %d", exec_mode);
719 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
720 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
721 tty->print_cr(" Interpreted frames:");
722 for (int k = 0; k < cur_array->frames(); k++) {
723 vframeArrayElement* el = cur_array->element(k);
724 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
725 }
726 cur_array->print_on_2(tty);
727 guarantee(false, "wrong number of expression stack elements during deopt");
728 }
729 VerifyOopClosure verify;
730 iframe->oops_interpreted_do(&verify, NULL, &rm, false);
731 callee_size_of_parameters = mh->size_of_parameters();
732 callee_max_locals = mh->max_locals();
733 is_top_frame = false;
734 }
735 }
736 #endif /* !PRODUCT */
739 return bt;
740 JRT_END
743 int Deoptimization::deoptimize_dependents() {
744 Threads::deoptimized_wrt_marked_nmethods();
745 return 0;
746 }
749 #ifdef COMPILER2
750 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
751 Handle pending_exception(thread->pending_exception());
752 const char* exception_file = thread->exception_file();
753 int exception_line = thread->exception_line();
754 thread->clear_pending_exception();
756 for (int i = 0; i < objects->length(); i++) {
757 assert(objects->at(i)->is_object(), "invalid debug information");
758 ObjectValue* sv = (ObjectValue*) objects->at(i);
760 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
761 oop obj = NULL;
763 if (k->oop_is_instance()) {
764 InstanceKlass* ik = InstanceKlass::cast(k());
765 obj = ik->allocate_instance(CHECK_(false));
766 } else if (k->oop_is_typeArray()) {
767 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
768 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
769 int len = sv->field_size() / type2size[ak->element_type()];
770 obj = ak->allocate(len, CHECK_(false));
771 } else if (k->oop_is_objArray()) {
772 ObjArrayKlass* ak = ObjArrayKlass::cast(k());
773 obj = ak->allocate(sv->field_size(), CHECK_(false));
774 }
776 assert(obj != NULL, "allocation failed");
777 assert(sv->value().is_null(), "redundant reallocation");
778 sv->set_value(obj);
779 }
781 if (pending_exception.not_null()) {
782 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
783 }
785 return true;
786 }
788 // This assumes that the fields are stored in ObjectValue in the same order
789 // they are yielded by do_nonstatic_fields.
790 class FieldReassigner: public FieldClosure {
791 frame* _fr;
792 RegisterMap* _reg_map;
793 ObjectValue* _sv;
794 InstanceKlass* _ik;
795 oop _obj;
797 int _i;
798 public:
799 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
800 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
802 int i() const { return _i; }
805 void do_field(fieldDescriptor* fd) {
806 intptr_t val;
807 StackValue* value =
808 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
809 int offset = fd->offset();
810 switch (fd->field_type()) {
811 case T_OBJECT: case T_ARRAY:
812 assert(value->type() == T_OBJECT, "Agreement.");
813 _obj->obj_field_put(offset, value->get_obj()());
814 break;
816 case T_LONG: case T_DOUBLE: {
817 assert(value->type() == T_INT, "Agreement.");
818 StackValue* low =
819 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
820 #ifdef _LP64
821 jlong res = (jlong)low->get_int();
822 #else
823 #ifdef SPARC
824 // For SPARC we have to swap high and low words.
825 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
826 #else
827 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
828 #endif //SPARC
829 #endif
830 _obj->long_field_put(offset, res);
831 break;
832 }
833 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
834 case T_INT: case T_FLOAT: // 4 bytes.
835 assert(value->type() == T_INT, "Agreement.");
836 val = value->get_int();
837 _obj->int_field_put(offset, (jint)*((jint*)&val));
838 break;
840 case T_SHORT: case T_CHAR: // 2 bytes
841 assert(value->type() == T_INT, "Agreement.");
842 val = value->get_int();
843 _obj->short_field_put(offset, (jshort)*((jint*)&val));
844 break;
846 case T_BOOLEAN: case T_BYTE: // 1 byte
847 assert(value->type() == T_INT, "Agreement.");
848 val = value->get_int();
849 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
850 break;
852 default:
853 ShouldNotReachHere();
854 }
855 _i++;
856 }
857 };
859 // restore elements of an eliminated type array
860 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
861 int index = 0;
862 intptr_t val;
864 for (int i = 0; i < sv->field_size(); i++) {
865 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
866 switch(type) {
867 case T_LONG: case T_DOUBLE: {
868 assert(value->type() == T_INT, "Agreement.");
869 StackValue* low =
870 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
871 #ifdef _LP64
872 jlong res = (jlong)low->get_int();
873 #else
874 #ifdef SPARC
875 // For SPARC we have to swap high and low words.
876 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
877 #else
878 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
879 #endif //SPARC
880 #endif
881 obj->long_at_put(index, res);
882 break;
883 }
885 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
886 case T_INT: case T_FLOAT: // 4 bytes.
887 assert(value->type() == T_INT, "Agreement.");
888 val = value->get_int();
889 obj->int_at_put(index, (jint)*((jint*)&val));
890 break;
892 case T_SHORT: case T_CHAR: // 2 bytes
893 assert(value->type() == T_INT, "Agreement.");
894 val = value->get_int();
895 obj->short_at_put(index, (jshort)*((jint*)&val));
896 break;
898 case T_BOOLEAN: case T_BYTE: // 1 byte
899 assert(value->type() == T_INT, "Agreement.");
900 val = value->get_int();
901 obj->bool_at_put(index, (jboolean)*((jint*)&val));
902 break;
904 default:
905 ShouldNotReachHere();
906 }
907 index++;
908 }
909 }
912 // restore fields of an eliminated object array
913 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
914 for (int i = 0; i < sv->field_size(); i++) {
915 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
916 assert(value->type() == T_OBJECT, "object element expected");
917 obj->obj_at_put(i, value->get_obj()());
918 }
919 }
922 // restore fields of all eliminated objects and arrays
923 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
924 for (int i = 0; i < objects->length(); i++) {
925 ObjectValue* sv = (ObjectValue*) objects->at(i);
926 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
927 Handle obj = sv->value();
928 assert(obj.not_null(), "reallocation was missed");
930 if (k->oop_is_instance()) {
931 InstanceKlass* ik = InstanceKlass::cast(k());
932 FieldReassigner reassign(fr, reg_map, sv, obj());
933 ik->do_nonstatic_fields(&reassign);
934 } else if (k->oop_is_typeArray()) {
935 TypeArrayKlass* ak = TypeArrayKlass::cast(k());
936 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
937 } else if (k->oop_is_objArray()) {
938 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
939 }
940 }
941 }
944 // relock objects for which synchronization was eliminated
945 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
946 for (int i = 0; i < monitors->length(); i++) {
947 MonitorInfo* mon_info = monitors->at(i);
948 if (mon_info->eliminated()) {
949 assert(mon_info->owner() != NULL, "reallocation was missed");
950 Handle obj = Handle(mon_info->owner());
951 markOop mark = obj->mark();
952 if (UseBiasedLocking && mark->has_bias_pattern()) {
953 // New allocated objects may have the mark set to anonymously biased.
954 // Also the deoptimized method may called methods with synchronization
955 // where the thread-local object is bias locked to the current thread.
956 assert(mark->is_biased_anonymously() ||
957 mark->biased_locker() == thread, "should be locked to current thread");
958 // Reset mark word to unbiased prototype.
959 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
960 obj->set_mark(unbiased_prototype);
961 }
962 BasicLock* lock = mon_info->lock();
963 ObjectSynchronizer::slow_enter(obj, lock, thread);
964 }
965 assert(mon_info->owner()->is_locked(), "object must be locked now");
966 }
967 }
970 #ifndef PRODUCT
971 // print information about reallocated objects
972 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
973 fieldDescriptor fd;
975 for (int i = 0; i < objects->length(); i++) {
976 ObjectValue* sv = (ObjectValue*) objects->at(i);
977 KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
978 Handle obj = sv->value();
980 tty->print(" object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
981 k->print_value();
982 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
983 tty->cr();
985 if (Verbose) {
986 k->oop_print_on(obj(), tty);
987 }
988 }
989 }
990 #endif
991 #endif // COMPILER2
993 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
994 Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
996 #ifndef PRODUCT
997 if (TraceDeoptimization) {
998 ttyLocker ttyl;
999 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
1000 fr.print_on(tty);
1001 tty->print_cr(" Virtual frames (innermost first):");
1002 for (int index = 0; index < chunk->length(); index++) {
1003 compiledVFrame* vf = chunk->at(index);
1004 tty->print(" %2d - ", index);
1005 vf->print_value();
1006 int bci = chunk->at(index)->raw_bci();
1007 const char* code_name;
1008 if (bci == SynchronizationEntryBCI) {
1009 code_name = "sync entry";
1010 } else {
1011 Bytecodes::Code code = vf->method()->code_at(bci);
1012 code_name = Bytecodes::name(code);
1013 }
1014 tty->print(" - %s", code_name);
1015 tty->print_cr(" @ bci %d ", bci);
1016 if (Verbose) {
1017 vf->print();
1018 tty->cr();
1019 }
1020 }
1021 }
1022 #endif
1024 // Register map for next frame (used for stack crawl). We capture
1025 // the state of the deopt'ing frame's caller. Thus if we need to
1026 // stuff a C2I adapter we can properly fill in the callee-save
1027 // register locations.
1028 frame caller = fr.sender(reg_map);
1029 int frame_size = caller.sp() - fr.sp();
1031 frame sender = caller;
1033 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1034 // the vframeArray containing the unpacking information is allocated in the C heap.
1035 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1036 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1038 // Compare the vframeArray to the collected vframes
1039 assert(array->structural_compare(thread, chunk), "just checking");
1041 #ifndef PRODUCT
1042 if (TraceDeoptimization) {
1043 ttyLocker ttyl;
1044 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1045 }
1046 #endif // PRODUCT
1048 return array;
1049 }
1052 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1053 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1054 for (int i = 0; i < monitors->length(); i++) {
1055 MonitorInfo* mon_info = monitors->at(i);
1056 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1057 objects_to_revoke->append(Handle(mon_info->owner()));
1058 }
1059 }
1060 }
1063 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1064 if (!UseBiasedLocking) {
1065 return;
1066 }
1068 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1070 // Unfortunately we don't have a RegisterMap available in most of
1071 // the places we want to call this routine so we need to walk the
1072 // stack again to update the register map.
1073 if (map == NULL || !map->update_map()) {
1074 StackFrameStream sfs(thread, true);
1075 bool found = false;
1076 while (!found && !sfs.is_done()) {
1077 frame* cur = sfs.current();
1078 sfs.next();
1079 found = cur->id() == fr.id();
1080 }
1081 assert(found, "frame to be deoptimized not found on target thread's stack");
1082 map = sfs.register_map();
1083 }
1085 vframe* vf = vframe::new_vframe(&fr, map, thread);
1086 compiledVFrame* cvf = compiledVFrame::cast(vf);
1087 // Revoke monitors' biases in all scopes
1088 while (!cvf->is_top()) {
1089 collect_monitors(cvf, objects_to_revoke);
1090 cvf = compiledVFrame::cast(cvf->sender());
1091 }
1092 collect_monitors(cvf, objects_to_revoke);
1094 if (SafepointSynchronize::is_at_safepoint()) {
1095 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1096 } else {
1097 BiasedLocking::revoke(objects_to_revoke);
1098 }
1099 }
1102 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1103 if (!UseBiasedLocking) {
1104 return;
1105 }
1107 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1108 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1109 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1110 if (jt->has_last_Java_frame()) {
1111 StackFrameStream sfs(jt, true);
1112 while (!sfs.is_done()) {
1113 frame* cur = sfs.current();
1114 if (cb->contains(cur->pc())) {
1115 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1116 compiledVFrame* cvf = compiledVFrame::cast(vf);
1117 // Revoke monitors' biases in all scopes
1118 while (!cvf->is_top()) {
1119 collect_monitors(cvf, objects_to_revoke);
1120 cvf = compiledVFrame::cast(cvf->sender());
1121 }
1122 collect_monitors(cvf, objects_to_revoke);
1123 }
1124 sfs.next();
1125 }
1126 }
1127 }
1128 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1129 }
1132 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1133 assert(fr.can_be_deoptimized(), "checking frame type");
1135 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1137 // Patch the nmethod so that when execution returns to it we will
1138 // deopt the execution state and return to the interpreter.
1139 fr.deoptimize(thread);
1140 }
1142 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1143 // Deoptimize only if the frame comes from compile code.
1144 // Do not deoptimize the frame which is already patched
1145 // during the execution of the loops below.
1146 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1147 return;
1148 }
1149 ResourceMark rm;
1150 DeoptimizationMarker dm;
1151 if (UseBiasedLocking) {
1152 revoke_biases_of_monitors(thread, fr, map);
1153 }
1154 deoptimize_single_frame(thread, fr);
1156 }
1159 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1160 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1161 "can only deoptimize other thread at a safepoint");
1162 // Compute frame and register map based on thread and sp.
1163 RegisterMap reg_map(thread, UseBiasedLocking);
1164 frame fr = thread->last_frame();
1165 while (fr.id() != id) {
1166 fr = fr.sender(®_map);
1167 }
1168 deoptimize(thread, fr, ®_map);
1169 }
1172 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1173 if (thread == Thread::current()) {
1174 Deoptimization::deoptimize_frame_internal(thread, id);
1175 } else {
1176 VM_DeoptimizeFrame deopt(thread, id);
1177 VMThread::execute(&deopt);
1178 }
1179 }
1182 // JVMTI PopFrame support
1183 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1184 {
1185 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1186 }
1187 JRT_END
1190 #if defined(COMPILER2) || defined(SHARK)
1191 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1192 // in case of an unresolved klass entry, load the class.
1193 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1194 Klass* tk = constant_pool->klass_at(index, CHECK);
1195 return;
1196 }
1198 if (!constant_pool->tag_at(index).is_symbol()) return;
1200 Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1201 Symbol* symbol = constant_pool->symbol_at(index);
1203 // class name?
1204 if (symbol->byte_at(0) != '(') {
1205 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1206 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1207 return;
1208 }
1210 // then it must be a signature!
1211 ResourceMark rm(THREAD);
1212 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1213 if (ss.is_object()) {
1214 Symbol* class_name = ss.as_symbol(CHECK);
1215 Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1216 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1217 }
1218 }
1219 }
1222 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1223 EXCEPTION_MARK;
1224 load_class_by_index(constant_pool, index, THREAD);
1225 if (HAS_PENDING_EXCEPTION) {
1226 // Exception happened during classloading. We ignore the exception here, since it
1227 // is going to be rethrown since the current activation is going to be deoptimized and
1228 // the interpreter will re-execute the bytecode.
1229 CLEAR_PENDING_EXCEPTION;
1230 // Class loading called java code which may have caused a stack
1231 // overflow. If the exception was thrown right before the return
1232 // to the runtime the stack is no longer guarded. Reguard the
1233 // stack otherwise if we return to the uncommon trap blob and the
1234 // stack bang causes a stack overflow we crash.
1235 assert(THREAD->is_Java_thread(), "only a java thread can be here");
1236 JavaThread* thread = (JavaThread*)THREAD;
1237 bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1238 if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1239 assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1240 }
1241 }
1243 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1244 HandleMark hm;
1246 // uncommon_trap() is called at the beginning of the uncommon trap
1247 // handler. Note this fact before we start generating temporary frames
1248 // that can confuse an asynchronous stack walker. This counter is
1249 // decremented at the end of unpack_frames().
1250 thread->inc_in_deopt_handler();
1252 // We need to update the map if we have biased locking.
1253 RegisterMap reg_map(thread, UseBiasedLocking);
1254 frame stub_frame = thread->last_frame();
1255 frame fr = stub_frame.sender(®_map);
1256 // Make sure the calling nmethod is not getting deoptimized and removed
1257 // before we are done with it.
1258 nmethodLocker nl(fr.pc());
1260 // Log a message
1261 Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1262 trap_request, fr.pc());
1264 {
1265 ResourceMark rm;
1267 // Revoke biases of any monitors in the frame to ensure we can migrate them
1268 revoke_biases_of_monitors(thread, fr, ®_map);
1270 DeoptReason reason = trap_request_reason(trap_request);
1271 DeoptAction action = trap_request_action(trap_request);
1272 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1274 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1275 compiledVFrame* cvf = compiledVFrame::cast(vf);
1277 nmethod* nm = cvf->code();
1279 ScopeDesc* trap_scope = cvf->scope();
1280 methodHandle trap_method = trap_scope->method();
1281 int trap_bci = trap_scope->bci();
1282 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1284 // Record this event in the histogram.
1285 gather_statistics(reason, action, trap_bc);
1287 // Ensure that we can record deopt. history:
1288 // Need MDO to record RTM code generation state.
1289 bool create_if_missing = ProfileTraps RTM_OPT_ONLY( || UseRTMLocking );
1291 MethodData* trap_mdo =
1292 get_method_data(thread, trap_method, create_if_missing);
1294 // Log a message
1295 Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1296 trap_reason_name(reason), trap_action_name(action), fr.pc(),
1297 trap_method->name_and_sig_as_C_string(), trap_bci);
1299 // Print a bunch of diagnostics, if requested.
1300 if (TraceDeoptimization || LogCompilation) {
1301 ResourceMark rm;
1302 ttyLocker ttyl;
1303 char buf[100];
1304 if (xtty != NULL) {
1305 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1306 os::current_thread_id(),
1307 format_trap_request(buf, sizeof(buf), trap_request));
1308 nm->log_identity(xtty);
1309 }
1310 Symbol* class_name = NULL;
1311 bool unresolved = false;
1312 if (unloaded_class_index >= 0) {
1313 constantPoolHandle constants (THREAD, trap_method->constants());
1314 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1315 class_name = constants->klass_name_at(unloaded_class_index);
1316 unresolved = true;
1317 if (xtty != NULL)
1318 xtty->print(" unresolved='1'");
1319 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1320 class_name = constants->symbol_at(unloaded_class_index);
1321 }
1322 if (xtty != NULL)
1323 xtty->name(class_name);
1324 }
1325 if (xtty != NULL && trap_mdo != NULL) {
1326 // Dump the relevant MDO state.
1327 // This is the deopt count for the current reason, any previous
1328 // reasons or recompiles seen at this point.
1329 int dcnt = trap_mdo->trap_count(reason);
1330 if (dcnt != 0)
1331 xtty->print(" count='%d'", dcnt);
1332 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1333 int dos = (pdata == NULL)? 0: pdata->trap_state();
1334 if (dos != 0) {
1335 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1336 if (trap_state_is_recompiled(dos)) {
1337 int recnt2 = trap_mdo->overflow_recompile_count();
1338 if (recnt2 != 0)
1339 xtty->print(" recompiles2='%d'", recnt2);
1340 }
1341 }
1342 }
1343 if (xtty != NULL) {
1344 xtty->stamp();
1345 xtty->end_head();
1346 }
1347 if (TraceDeoptimization) { // make noise on the tty
1348 tty->print("Uncommon trap occurred in");
1349 nm->method()->print_short_name(tty);
1350 tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1351 fr.pc(),
1352 os::current_thread_id(),
1353 trap_reason_name(reason),
1354 trap_action_name(action),
1355 unloaded_class_index);
1356 if (class_name != NULL) {
1357 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1358 class_name->print_symbol_on(tty);
1359 }
1360 tty->cr();
1361 }
1362 if (xtty != NULL) {
1363 // Log the precise location of the trap.
1364 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1365 xtty->begin_elem("jvms bci='%d'", sd->bci());
1366 xtty->method(sd->method());
1367 xtty->end_elem();
1368 if (sd->is_top()) break;
1369 }
1370 xtty->tail("uncommon_trap");
1371 }
1372 }
1373 // (End diagnostic printout.)
1375 // Load class if necessary
1376 if (unloaded_class_index >= 0) {
1377 constantPoolHandle constants(THREAD, trap_method->constants());
1378 load_class_by_index(constants, unloaded_class_index);
1379 }
1381 // Flush the nmethod if necessary and desirable.
1382 //
1383 // We need to avoid situations where we are re-flushing the nmethod
1384 // because of a hot deoptimization site. Repeated flushes at the same
1385 // point need to be detected by the compiler and avoided. If the compiler
1386 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1387 // module must take measures to avoid an infinite cycle of recompilation
1388 // and deoptimization. There are several such measures:
1389 //
1390 // 1. If a recompilation is ordered a second time at some site X
1391 // and for the same reason R, the action is adjusted to 'reinterpret',
1392 // to give the interpreter time to exercise the method more thoroughly.
1393 // If this happens, the method's overflow_recompile_count is incremented.
1394 //
1395 // 2. If the compiler fails to reduce the deoptimization rate, then
1396 // the method's overflow_recompile_count will begin to exceed the set
1397 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1398 // is adjusted to 'make_not_compilable', and the method is abandoned
1399 // to the interpreter. This is a performance hit for hot methods,
1400 // but is better than a disastrous infinite cycle of recompilations.
1401 // (Actually, only the method containing the site X is abandoned.)
1402 //
1403 // 3. In parallel with the previous measures, if the total number of
1404 // recompilations of a method exceeds the much larger set limit
1405 // PerMethodRecompilationCutoff, the method is abandoned.
1406 // This should only happen if the method is very large and has
1407 // many "lukewarm" deoptimizations. The code which enforces this
1408 // limit is elsewhere (class nmethod, class Method).
1409 //
1410 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1411 // to recompile at each bytecode independently of the per-BCI cutoff.
1412 //
1413 // The decision to update code is up to the compiler, and is encoded
1414 // in the Action_xxx code. If the compiler requests Action_none
1415 // no trap state is changed, no compiled code is changed, and the
1416 // computation suffers along in the interpreter.
1417 //
1418 // The other action codes specify various tactics for decompilation
1419 // and recompilation. Action_maybe_recompile is the loosest, and
1420 // allows the compiled code to stay around until enough traps are seen,
1421 // and until the compiler gets around to recompiling the trapping method.
1422 //
1423 // The other actions cause immediate removal of the present code.
1425 bool update_trap_state = true;
1426 bool make_not_entrant = false;
1427 bool make_not_compilable = false;
1428 bool reprofile = false;
1429 switch (action) {
1430 case Action_none:
1431 // Keep the old code.
1432 update_trap_state = false;
1433 break;
1434 case Action_maybe_recompile:
1435 // Do not need to invalidate the present code, but we can
1436 // initiate another
1437 // Start compiler without (necessarily) invalidating the nmethod.
1438 // The system will tolerate the old code, but new code should be
1439 // generated when possible.
1440 break;
1441 case Action_reinterpret:
1442 // Go back into the interpreter for a while, and then consider
1443 // recompiling form scratch.
1444 make_not_entrant = true;
1445 // Reset invocation counter for outer most method.
1446 // This will allow the interpreter to exercise the bytecodes
1447 // for a while before recompiling.
1448 // By contrast, Action_make_not_entrant is immediate.
1449 //
1450 // Note that the compiler will track null_check, null_assert,
1451 // range_check, and class_check events and log them as if they
1452 // had been traps taken from compiled code. This will update
1453 // the MDO trap history so that the next compilation will
1454 // properly detect hot trap sites.
1455 reprofile = true;
1456 break;
1457 case Action_make_not_entrant:
1458 // Request immediate recompilation, and get rid of the old code.
1459 // Make them not entrant, so next time they are called they get
1460 // recompiled. Unloaded classes are loaded now so recompile before next
1461 // time they are called. Same for uninitialized. The interpreter will
1462 // link the missing class, if any.
1463 make_not_entrant = true;
1464 break;
1465 case Action_make_not_compilable:
1466 // Give up on compiling this method at all.
1467 make_not_entrant = true;
1468 make_not_compilable = true;
1469 break;
1470 default:
1471 ShouldNotReachHere();
1472 }
1474 // Setting +ProfileTraps fixes the following, on all platforms:
1475 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1476 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1477 // recompile relies on a MethodData* to record heroic opt failures.
1479 // Whether the interpreter is producing MDO data or not, we also need
1480 // to use the MDO to detect hot deoptimization points and control
1481 // aggressive optimization.
1482 bool inc_recompile_count = false;
1483 ProfileData* pdata = NULL;
1484 if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1485 assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1486 uint this_trap_count = 0;
1487 bool maybe_prior_trap = false;
1488 bool maybe_prior_recompile = false;
1489 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1490 nm->method(),
1491 //outputs:
1492 this_trap_count,
1493 maybe_prior_trap,
1494 maybe_prior_recompile);
1495 // Because the interpreter also counts null, div0, range, and class
1496 // checks, these traps from compiled code are double-counted.
1497 // This is harmless; it just means that the PerXTrapLimit values
1498 // are in effect a little smaller than they look.
1500 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1501 if (per_bc_reason != Reason_none) {
1502 // Now take action based on the partially known per-BCI history.
1503 if (maybe_prior_trap
1504 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1505 // If there are too many traps at this BCI, force a recompile.
1506 // This will allow the compiler to see the limit overflow, and
1507 // take corrective action, if possible. The compiler generally
1508 // does not use the exact PerBytecodeTrapLimit value, but instead
1509 // changes its tactics if it sees any traps at all. This provides
1510 // a little hysteresis, delaying a recompile until a trap happens
1511 // several times.
1512 //
1513 // Actually, since there is only one bit of counter per BCI,
1514 // the possible per-BCI counts are {0,1,(per-method count)}.
1515 // This produces accurate results if in fact there is only
1516 // one hot trap site, but begins to get fuzzy if there are
1517 // many sites. For example, if there are ten sites each
1518 // trapping two or more times, they each get the blame for
1519 // all of their traps.
1520 make_not_entrant = true;
1521 }
1523 // Detect repeated recompilation at the same BCI, and enforce a limit.
1524 if (make_not_entrant && maybe_prior_recompile) {
1525 // More than one recompile at this point.
1526 inc_recompile_count = maybe_prior_trap;
1527 }
1528 } else {
1529 // For reasons which are not recorded per-bytecode, we simply
1530 // force recompiles unconditionally.
1531 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1532 make_not_entrant = true;
1533 }
1535 // Go back to the compiler if there are too many traps in this method.
1536 if (this_trap_count >= per_method_trap_limit(reason)) {
1537 // If there are too many traps in this method, force a recompile.
1538 // This will allow the compiler to see the limit overflow, and
1539 // take corrective action, if possible.
1540 // (This condition is an unlikely backstop only, because the
1541 // PerBytecodeTrapLimit is more likely to take effect first,
1542 // if it is applicable.)
1543 make_not_entrant = true;
1544 }
1546 // Here's more hysteresis: If there has been a recompile at
1547 // this trap point already, run the method in the interpreter
1548 // for a while to exercise it more thoroughly.
1549 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1550 reprofile = true;
1551 }
1553 }
1555 // Take requested actions on the method:
1557 // Recompile
1558 if (make_not_entrant) {
1559 if (!nm->make_not_entrant()) {
1560 return; // the call did not change nmethod's state
1561 }
1563 if (pdata != NULL) {
1564 // Record the recompilation event, if any.
1565 int tstate0 = pdata->trap_state();
1566 int tstate1 = trap_state_set_recompiled(tstate0, true);
1567 if (tstate1 != tstate0)
1568 pdata->set_trap_state(tstate1);
1569 }
1571 #if INCLUDE_RTM_OPT
1572 // Restart collecting RTM locking abort statistic if the method
1573 // is recompiled for a reason other than RTM state change.
1574 // Assume that in new recompiled code the statistic could be different,
1575 // for example, due to different inlining.
1576 if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1577 UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1578 trap_mdo->atomic_set_rtm_state(ProfileRTM);
1579 }
1580 #endif
1581 }
1583 if (inc_recompile_count) {
1584 trap_mdo->inc_overflow_recompile_count();
1585 if ((uint)trap_mdo->overflow_recompile_count() >
1586 (uint)PerBytecodeRecompilationCutoff) {
1587 // Give up on the method containing the bad BCI.
1588 if (trap_method() == nm->method()) {
1589 make_not_compilable = true;
1590 } else {
1591 trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1592 // But give grace to the enclosing nm->method().
1593 }
1594 }
1595 }
1597 // Reprofile
1598 if (reprofile) {
1599 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1600 }
1602 // Give up compiling
1603 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1604 assert(make_not_entrant, "consistent");
1605 nm->method()->set_not_compilable(CompLevel_full_optimization);
1606 }
1608 } // Free marked resources
1610 }
1611 JRT_END
1613 MethodData*
1614 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1615 bool create_if_missing) {
1616 Thread* THREAD = thread;
1617 MethodData* mdo = m()->method_data();
1618 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1619 // Build an MDO. Ignore errors like OutOfMemory;
1620 // that simply means we won't have an MDO to update.
1621 Method::build_interpreter_method_data(m, THREAD);
1622 if (HAS_PENDING_EXCEPTION) {
1623 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1624 CLEAR_PENDING_EXCEPTION;
1625 }
1626 mdo = m()->method_data();
1627 }
1628 return mdo;
1629 }
1631 ProfileData*
1632 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1633 int trap_bci,
1634 Deoptimization::DeoptReason reason,
1635 Method* compiled_method,
1636 //outputs:
1637 uint& ret_this_trap_count,
1638 bool& ret_maybe_prior_trap,
1639 bool& ret_maybe_prior_recompile) {
1640 uint prior_trap_count = trap_mdo->trap_count(reason);
1641 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1643 // If the runtime cannot find a place to store trap history,
1644 // it is estimated based on the general condition of the method.
1645 // If the method has ever been recompiled, or has ever incurred
1646 // a trap with the present reason , then this BCI is assumed
1647 // (pessimistically) to be the culprit.
1648 bool maybe_prior_trap = (prior_trap_count != 0);
1649 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1650 ProfileData* pdata = NULL;
1653 // For reasons which are recorded per bytecode, we check per-BCI data.
1654 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1655 if (per_bc_reason != Reason_none) {
1656 // Find the profile data for this BCI. If there isn't one,
1657 // try to allocate one from the MDO's set of spares.
1658 // This will let us detect a repeated trap at this point.
1659 pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1661 if (pdata != NULL) {
1662 if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1663 if (LogCompilation && xtty != NULL) {
1664 ttyLocker ttyl;
1665 // no more room for speculative traps in this MDO
1666 xtty->elem("speculative_traps_oom");
1667 }
1668 }
1669 // Query the trap state of this profile datum.
1670 int tstate0 = pdata->trap_state();
1671 if (!trap_state_has_reason(tstate0, per_bc_reason))
1672 maybe_prior_trap = false;
1673 if (!trap_state_is_recompiled(tstate0))
1674 maybe_prior_recompile = false;
1676 // Update the trap state of this profile datum.
1677 int tstate1 = tstate0;
1678 // Record the reason.
1679 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1680 // Store the updated state on the MDO, for next time.
1681 if (tstate1 != tstate0)
1682 pdata->set_trap_state(tstate1);
1683 } else {
1684 if (LogCompilation && xtty != NULL) {
1685 ttyLocker ttyl;
1686 // Missing MDP? Leave a small complaint in the log.
1687 xtty->elem("missing_mdp bci='%d'", trap_bci);
1688 }
1689 }
1690 }
1692 // Return results:
1693 ret_this_trap_count = this_trap_count;
1694 ret_maybe_prior_trap = maybe_prior_trap;
1695 ret_maybe_prior_recompile = maybe_prior_recompile;
1696 return pdata;
1697 }
1699 void
1700 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1701 ResourceMark rm;
1702 // Ignored outputs:
1703 uint ignore_this_trap_count;
1704 bool ignore_maybe_prior_trap;
1705 bool ignore_maybe_prior_recompile;
1706 assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1707 query_update_method_data(trap_mdo, trap_bci,
1708 (DeoptReason)reason,
1709 NULL,
1710 ignore_this_trap_count,
1711 ignore_maybe_prior_trap,
1712 ignore_maybe_prior_recompile);
1713 }
1715 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1717 // Still in Java no safepoints
1718 {
1719 // This enters VM and may safepoint
1720 uncommon_trap_inner(thread, trap_request);
1721 }
1722 return fetch_unroll_info_helper(thread);
1723 }
1725 // Local derived constants.
1726 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1727 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1728 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1730 //---------------------------trap_state_reason---------------------------------
1731 Deoptimization::DeoptReason
1732 Deoptimization::trap_state_reason(int trap_state) {
1733 // This assert provides the link between the width of DataLayout::trap_bits
1734 // and the encoding of "recorded" reasons. It ensures there are enough
1735 // bits to store all needed reasons in the per-BCI MDO profile.
1736 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1737 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1738 trap_state -= recompile_bit;
1739 if (trap_state == DS_REASON_MASK) {
1740 return Reason_many;
1741 } else {
1742 assert((int)Reason_none == 0, "state=0 => Reason_none");
1743 return (DeoptReason)trap_state;
1744 }
1745 }
1746 //-------------------------trap_state_has_reason-------------------------------
1747 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1748 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1749 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1750 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1751 trap_state -= recompile_bit;
1752 if (trap_state == DS_REASON_MASK) {
1753 return -1; // true, unspecifically (bottom of state lattice)
1754 } else if (trap_state == reason) {
1755 return 1; // true, definitely
1756 } else if (trap_state == 0) {
1757 return 0; // false, definitely (top of state lattice)
1758 } else {
1759 return 0; // false, definitely
1760 }
1761 }
1762 //-------------------------trap_state_add_reason-------------------------------
1763 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1764 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1765 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1766 trap_state -= recompile_bit;
1767 if (trap_state == DS_REASON_MASK) {
1768 return trap_state + recompile_bit; // already at state lattice bottom
1769 } else if (trap_state == reason) {
1770 return trap_state + recompile_bit; // the condition is already true
1771 } else if (trap_state == 0) {
1772 return reason + recompile_bit; // no condition has yet been true
1773 } else {
1774 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1775 }
1776 }
1777 //-----------------------trap_state_is_recompiled------------------------------
1778 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1779 return (trap_state & DS_RECOMPILE_BIT) != 0;
1780 }
1781 //-----------------------trap_state_set_recompiled-----------------------------
1782 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1783 if (z) return trap_state | DS_RECOMPILE_BIT;
1784 else return trap_state & ~DS_RECOMPILE_BIT;
1785 }
1786 //---------------------------format_trap_state---------------------------------
1787 // This is used for debugging and diagnostics, including LogFile output.
1788 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1789 int trap_state) {
1790 DeoptReason reason = trap_state_reason(trap_state);
1791 bool recomp_flag = trap_state_is_recompiled(trap_state);
1792 // Re-encode the state from its decoded components.
1793 int decoded_state = 0;
1794 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1795 decoded_state = trap_state_add_reason(decoded_state, reason);
1796 if (recomp_flag)
1797 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1798 // If the state re-encodes properly, format it symbolically.
1799 // Because this routine is used for debugging and diagnostics,
1800 // be robust even if the state is a strange value.
1801 size_t len;
1802 if (decoded_state != trap_state) {
1803 // Random buggy state that doesn't decode??
1804 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1805 } else {
1806 len = jio_snprintf(buf, buflen, "%s%s",
1807 trap_reason_name(reason),
1808 recomp_flag ? " recompiled" : "");
1809 }
1810 if (len >= buflen)
1811 buf[buflen-1] = '\0';
1812 return buf;
1813 }
1816 //--------------------------------statics--------------------------------------
1817 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1818 = Deoptimization::Action_reinterpret;
1819 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1820 // Note: Keep this in sync. with enum DeoptReason.
1821 "none",
1822 "null_check",
1823 "null_assert",
1824 "range_check",
1825 "class_check",
1826 "array_check",
1827 "intrinsic",
1828 "bimorphic",
1829 "unloaded",
1830 "uninitialized",
1831 "unreached",
1832 "unhandled",
1833 "constraint",
1834 "div0_check",
1835 "age",
1836 "predicate",
1837 "loop_limit_check",
1838 "speculate_class_check",
1839 "rtm_state_change",
1840 "unstable_if"
1841 };
1842 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1843 // Note: Keep this in sync. with enum DeoptAction.
1844 "none",
1845 "maybe_recompile",
1846 "reinterpret",
1847 "make_not_entrant",
1848 "make_not_compilable"
1849 };
1851 const char* Deoptimization::trap_reason_name(int reason) {
1852 if (reason == Reason_many) return "many";
1853 if ((uint)reason < Reason_LIMIT)
1854 return _trap_reason_name[reason];
1855 static char buf[20];
1856 sprintf(buf, "reason%d", reason);
1857 return buf;
1858 }
1859 const char* Deoptimization::trap_action_name(int action) {
1860 if ((uint)action < Action_LIMIT)
1861 return _trap_action_name[action];
1862 static char buf[20];
1863 sprintf(buf, "action%d", action);
1864 return buf;
1865 }
1867 // This is used for debugging and diagnostics, including LogFile output.
1868 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1869 int trap_request) {
1870 jint unloaded_class_index = trap_request_index(trap_request);
1871 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1872 const char* action = trap_action_name(trap_request_action(trap_request));
1873 size_t len;
1874 if (unloaded_class_index < 0) {
1875 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1876 reason, action);
1877 } else {
1878 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1879 reason, action, unloaded_class_index);
1880 }
1881 if (len >= buflen)
1882 buf[buflen-1] = '\0';
1883 return buf;
1884 }
1886 juint Deoptimization::_deoptimization_hist
1887 [Deoptimization::Reason_LIMIT]
1888 [1 + Deoptimization::Action_LIMIT]
1889 [Deoptimization::BC_CASE_LIMIT]
1890 = {0};
1892 enum {
1893 LSB_BITS = 8,
1894 LSB_MASK = right_n_bits(LSB_BITS)
1895 };
1897 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1898 Bytecodes::Code bc) {
1899 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1900 assert(action >= 0 && action < Action_LIMIT, "oob");
1901 _deoptimization_hist[Reason_none][0][0] += 1; // total
1902 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1903 juint* cases = _deoptimization_hist[reason][1+action];
1904 juint* bc_counter_addr = NULL;
1905 juint bc_counter = 0;
1906 // Look for an unused counter, or an exact match to this BC.
1907 if (bc != Bytecodes::_illegal) {
1908 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1909 juint* counter_addr = &cases[bc_case];
1910 juint counter = *counter_addr;
1911 if ((counter == 0 && bc_counter_addr == NULL)
1912 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1913 // this counter is either free or is already devoted to this BC
1914 bc_counter_addr = counter_addr;
1915 bc_counter = counter | bc;
1916 }
1917 }
1918 }
1919 if (bc_counter_addr == NULL) {
1920 // Overflow, or no given bytecode.
1921 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1922 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1923 }
1924 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1925 }
1927 jint Deoptimization::total_deoptimization_count() {
1928 return _deoptimization_hist[Reason_none][0][0];
1929 }
1931 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1932 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1933 return _deoptimization_hist[reason][0][0];
1934 }
1936 void Deoptimization::print_statistics() {
1937 juint total = total_deoptimization_count();
1938 juint account = total;
1939 if (total != 0) {
1940 ttyLocker ttyl;
1941 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1942 tty->print_cr("Deoptimization traps recorded:");
1943 #define PRINT_STAT_LINE(name, r) \
1944 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1945 PRINT_STAT_LINE("total", total);
1946 // For each non-zero entry in the histogram, print the reason,
1947 // the action, and (if specifically known) the type of bytecode.
1948 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1949 for (int action = 0; action < Action_LIMIT; action++) {
1950 juint* cases = _deoptimization_hist[reason][1+action];
1951 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1952 juint counter = cases[bc_case];
1953 if (counter != 0) {
1954 char name[1*K];
1955 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1956 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1957 bc = Bytecodes::_illegal;
1958 sprintf(name, "%s/%s/%s",
1959 trap_reason_name(reason),
1960 trap_action_name(action),
1961 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1962 juint r = counter >> LSB_BITS;
1963 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1964 account -= r;
1965 }
1966 }
1967 }
1968 }
1969 if (account != 0) {
1970 PRINT_STAT_LINE("unaccounted", account);
1971 }
1972 #undef PRINT_STAT_LINE
1973 if (xtty != NULL) xtty->tail("statistics");
1974 }
1975 }
1976 #else // COMPILER2 || SHARK
1979 // Stubs for C1 only system.
1980 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1981 return false;
1982 }
1984 const char* Deoptimization::trap_reason_name(int reason) {
1985 return "unknown";
1986 }
1988 void Deoptimization::print_statistics() {
1989 // no output
1990 }
1992 void
1993 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1994 // no udpate
1995 }
1997 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1998 return 0;
1999 }
2001 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2002 Bytecodes::Code bc) {
2003 // no update
2004 }
2006 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2007 int trap_state) {
2008 jio_snprintf(buf, buflen, "#%d", trap_state);
2009 return buf;
2010 }
2012 #endif // COMPILER2 || SHARK