Thu, 13 Jan 2011 22:15:41 -0800
4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed
1 /*
2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
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23 */
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/methodOop.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef COMPILER2
63 #ifdef TARGET_ARCH_MODEL_x86_32
64 # include "adfiles/ad_x86_32.hpp"
65 #endif
66 #ifdef TARGET_ARCH_MODEL_x86_64
67 # include "adfiles/ad_x86_64.hpp"
68 #endif
69 #ifdef TARGET_ARCH_MODEL_sparc
70 # include "adfiles/ad_sparc.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_zero
73 # include "adfiles/ad_zero.hpp"
74 #endif
75 #endif
77 bool DeoptimizationMarker::_is_active = false;
79 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
80 int caller_adjustment,
81 int number_of_frames,
82 intptr_t* frame_sizes,
83 address* frame_pcs,
84 BasicType return_type) {
85 _size_of_deoptimized_frame = size_of_deoptimized_frame;
86 _caller_adjustment = caller_adjustment;
87 _number_of_frames = number_of_frames;
88 _frame_sizes = frame_sizes;
89 _frame_pcs = frame_pcs;
90 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
91 _return_type = return_type;
92 // PD (x86 only)
93 _counter_temp = 0;
94 _initial_fp = 0;
95 _unpack_kind = 0;
96 _sender_sp_temp = 0;
98 _total_frame_sizes = size_of_frames();
99 }
102 Deoptimization::UnrollBlock::~UnrollBlock() {
103 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
104 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
105 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
106 }
109 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
110 assert(register_number < RegisterMap::reg_count, "checking register number");
111 return &_register_block[register_number * 2];
112 }
116 int Deoptimization::UnrollBlock::size_of_frames() const {
117 // Acount first for the adjustment of the initial frame
118 int result = _caller_adjustment;
119 for (int index = 0; index < number_of_frames(); index++) {
120 result += frame_sizes()[index];
121 }
122 return result;
123 }
126 void Deoptimization::UnrollBlock::print() {
127 ttyLocker ttyl;
128 tty->print_cr("UnrollBlock");
129 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
130 tty->print( " frame_sizes: ");
131 for (int index = 0; index < number_of_frames(); index++) {
132 tty->print("%d ", frame_sizes()[index]);
133 }
134 tty->cr();
135 }
138 // In order to make fetch_unroll_info work properly with escape
139 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
140 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
141 // of previously eliminated objects occurs in realloc_objects, which is
142 // called from the method fetch_unroll_info_helper below.
143 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
144 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
145 // but makes the entry a little slower. There is however a little dance we have to
146 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
148 // fetch_unroll_info() is called at the beginning of the deoptimization
149 // handler. Note this fact before we start generating temporary frames
150 // that can confuse an asynchronous stack walker. This counter is
151 // decremented at the end of unpack_frames().
152 thread->inc_in_deopt_handler();
154 return fetch_unroll_info_helper(thread);
155 JRT_END
158 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
159 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
161 // Note: there is a safepoint safety issue here. No matter whether we enter
162 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
163 // the vframeArray is created.
164 //
166 // Allocate our special deoptimization ResourceMark
167 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
168 assert(thread->deopt_mark() == NULL, "Pending deopt!");
169 thread->set_deopt_mark(dmark);
171 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
172 RegisterMap map(thread, true);
173 RegisterMap dummy_map(thread, false);
174 // Now get the deoptee with a valid map
175 frame deoptee = stub_frame.sender(&map);
176 // Set the deoptee nmethod
177 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
178 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
180 // Create a growable array of VFrames where each VFrame represents an inlined
181 // Java frame. This storage is allocated with the usual system arena.
182 assert(deoptee.is_compiled_frame(), "Wrong frame type");
183 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
184 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
185 while (!vf->is_top()) {
186 assert(vf->is_compiled_frame(), "Wrong frame type");
187 chunk->push(compiledVFrame::cast(vf));
188 vf = vf->sender();
189 }
190 assert(vf->is_compiled_frame(), "Wrong frame type");
191 chunk->push(compiledVFrame::cast(vf));
193 #ifdef COMPILER2
194 // Reallocate the non-escaping objects and restore their fields. Then
195 // relock objects if synchronization on them was eliminated.
196 if (DoEscapeAnalysis) {
197 if (EliminateAllocations) {
198 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
199 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
201 // The flag return_oop() indicates call sites which return oop
202 // in compiled code. Such sites include java method calls,
203 // runtime calls (for example, used to allocate new objects/arrays
204 // on slow code path) and any other calls generated in compiled code.
205 // It is not guaranteed that we can get such information here only
206 // by analyzing bytecode in deoptimized frames. This is why this flag
207 // is set during method compilation (see Compile::Process_OopMap_Node()).
208 bool save_oop_result = chunk->at(0)->scope()->return_oop();
209 Handle return_value;
210 if (save_oop_result) {
211 // Reallocation may trigger GC. If deoptimization happened on return from
212 // call which returns oop we need to save it since it is not in oopmap.
213 oop result = deoptee.saved_oop_result(&map);
214 assert(result == NULL || result->is_oop(), "must be oop");
215 return_value = Handle(thread, result);
216 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
217 if (TraceDeoptimization) {
218 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
219 }
220 }
221 bool reallocated = false;
222 if (objects != NULL) {
223 JRT_BLOCK
224 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
225 JRT_END
226 }
227 if (reallocated) {
228 reassign_fields(&deoptee, &map, objects);
229 #ifndef PRODUCT
230 if (TraceDeoptimization) {
231 ttyLocker ttyl;
232 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
233 print_objects(objects);
234 }
235 #endif
236 }
237 if (save_oop_result) {
238 // Restore result.
239 deoptee.set_saved_oop_result(&map, return_value());
240 }
241 }
242 if (EliminateLocks) {
243 #ifndef PRODUCT
244 bool first = true;
245 #endif
246 for (int i = 0; i < chunk->length(); i++) {
247 compiledVFrame* cvf = chunk->at(i);
248 assert (cvf->scope() != NULL,"expect only compiled java frames");
249 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
250 if (monitors->is_nonempty()) {
251 relock_objects(monitors, thread);
252 #ifndef PRODUCT
253 if (TraceDeoptimization) {
254 ttyLocker ttyl;
255 for (int j = 0; j < monitors->length(); j++) {
256 MonitorInfo* mi = monitors->at(j);
257 if (mi->eliminated()) {
258 if (first) {
259 first = false;
260 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
261 }
262 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
263 }
264 }
265 }
266 #endif
267 }
268 }
269 }
270 }
271 #endif // COMPILER2
272 // Ensure that no safepoint is taken after pointers have been stored
273 // in fields of rematerialized objects. If a safepoint occurs from here on
274 // out the java state residing in the vframeArray will be missed.
275 No_Safepoint_Verifier no_safepoint;
277 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
279 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
280 thread->set_vframe_array_head(array);
282 // Now that the vframeArray has been created if we have any deferred local writes
283 // added by jvmti then we can free up that structure as the data is now in the
284 // vframeArray
286 if (thread->deferred_locals() != NULL) {
287 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
288 int i = 0;
289 do {
290 // Because of inlining we could have multiple vframes for a single frame
291 // and several of the vframes could have deferred writes. Find them all.
292 if (list->at(i)->id() == array->original().id()) {
293 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
294 list->remove_at(i);
295 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
296 delete dlv;
297 } else {
298 i++;
299 }
300 } while ( i < list->length() );
301 if (list->length() == 0) {
302 thread->set_deferred_locals(NULL);
303 // free the list and elements back to C heap.
304 delete list;
305 }
307 }
309 #ifndef SHARK
310 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
311 CodeBlob* cb = stub_frame.cb();
312 // Verify we have the right vframeArray
313 assert(cb->frame_size() >= 0, "Unexpected frame size");
314 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
316 // If the deopt call site is a MethodHandle invoke call site we have
317 // to adjust the unpack_sp.
318 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
319 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
320 unpack_sp = deoptee.unextended_sp();
322 #ifdef ASSERT
323 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
324 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
325 #endif
326 #else
327 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
328 #endif // !SHARK
330 // This is a guarantee instead of an assert because if vframe doesn't match
331 // we will unpack the wrong deoptimized frame and wind up in strange places
332 // where it will be very difficult to figure out what went wrong. Better
333 // to die an early death here than some very obscure death later when the
334 // trail is cold.
335 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
336 // in that it will fail to detect a problem when there is one. This needs
337 // more work in tiger timeframe.
338 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
340 int number_of_frames = array->frames();
342 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
343 // virtual activation, which is the reverse of the elements in the vframes array.
344 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
345 // +1 because we always have an interpreter return address for the final slot.
346 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
347 int callee_parameters = 0;
348 int callee_locals = 0;
349 int popframe_extra_args = 0;
350 // Create an interpreter return address for the stub to use as its return
351 // address so the skeletal frames are perfectly walkable
352 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
354 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
355 // activation be put back on the expression stack of the caller for reexecution
356 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
357 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
358 }
360 //
361 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
362 // frame_sizes/frame_pcs[1] next oldest frame (int)
363 // frame_sizes/frame_pcs[n] youngest frame (int)
364 //
365 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
366 // owns the space for the return address to it's caller). Confusing ain't it.
367 //
368 // The vframe array can address vframes with indices running from
369 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
370 // When we create the skeletal frames we need the oldest frame to be in the zero slot
371 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
372 // so things look a little strange in this loop.
373 //
374 for (int index = 0; index < array->frames(); index++ ) {
375 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
376 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
377 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
378 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
379 callee_locals,
380 index == 0,
381 popframe_extra_args);
382 // This pc doesn't have to be perfect just good enough to identify the frame
383 // as interpreted so the skeleton frame will be walkable
384 // The correct pc will be set when the skeleton frame is completely filled out
385 // The final pc we store in the loop is wrong and will be overwritten below
386 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
388 callee_parameters = array->element(index)->method()->size_of_parameters();
389 callee_locals = array->element(index)->method()->max_locals();
390 popframe_extra_args = 0;
391 }
393 // Compute whether the root vframe returns a float or double value.
394 BasicType return_type;
395 {
396 HandleMark hm;
397 methodHandle method(thread, array->element(0)->method());
398 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
399 return_type = invoke.is_valid() ? invoke.result_type(thread) : T_ILLEGAL;
400 }
402 // Compute information for handling adapters and adjusting the frame size of the caller.
403 int caller_adjustment = 0;
405 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
406 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
407 // than simply use array->sender.pc(). This requires us to walk the current set of frames
408 //
409 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
410 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
412 // Compute the amount the oldest interpreter frame will have to adjust
413 // its caller's stack by. If the caller is a compiled frame then
414 // we pretend that the callee has no parameters so that the
415 // extension counts for the full amount of locals and not just
416 // locals-parms. This is because without a c2i adapter the parm
417 // area as created by the compiled frame will not be usable by
418 // the interpreter. (Depending on the calling convention there
419 // may not even be enough space).
421 // QQQ I'd rather see this pushed down into last_frame_adjust
422 // and have it take the sender (aka caller).
424 if (deopt_sender.is_compiled_frame()) {
425 caller_adjustment = last_frame_adjust(0, callee_locals);
426 } else if (callee_locals > callee_parameters) {
427 // The caller frame may need extending to accommodate
428 // non-parameter locals of the first unpacked interpreted frame.
429 // Compute that adjustment.
430 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
431 }
434 // If the sender is deoptimized the we must retrieve the address of the handler
435 // since the frame will "magically" show the original pc before the deopt
436 // and we'd undo the deopt.
438 frame_pcs[0] = deopt_sender.raw_pc();
440 #ifndef SHARK
441 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
442 #endif // SHARK
444 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
445 caller_adjustment * BytesPerWord,
446 number_of_frames,
447 frame_sizes,
448 frame_pcs,
449 return_type);
450 #if defined(IA32) || defined(AMD64)
451 // We need a way to pass fp to the unpacking code so the skeletal frames
452 // come out correct. This is only needed for x86 because of c2 using ebp
453 // as an allocatable register. So this update is useless (and harmless)
454 // on the other platforms. It would be nice to do this in a different
455 // way but even the old style deoptimization had a problem with deriving
456 // this value. NEEDS_CLEANUP
457 // Note: now that c1 is using c2's deopt blob we must do this on all
458 // x86 based platforms
459 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
460 *fp_addr = array->sender().fp(); // was adapter_caller
461 #endif /* IA32 || AMD64 */
463 if (array->frames() > 1) {
464 if (VerifyStack && TraceDeoptimization) {
465 tty->print_cr("Deoptimizing method containing inlining");
466 }
467 }
469 array->set_unroll_block(info);
470 return info;
471 }
473 // Called to cleanup deoptimization data structures in normal case
474 // after unpacking to stack and when stack overflow error occurs
475 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
476 vframeArray *array) {
478 // Get array if coming from exception
479 if (array == NULL) {
480 array = thread->vframe_array_head();
481 }
482 thread->set_vframe_array_head(NULL);
484 // Free the previous UnrollBlock
485 vframeArray* old_array = thread->vframe_array_last();
486 thread->set_vframe_array_last(array);
488 if (old_array != NULL) {
489 UnrollBlock* old_info = old_array->unroll_block();
490 old_array->set_unroll_block(NULL);
491 delete old_info;
492 delete old_array;
493 }
495 // Deallocate any resource creating in this routine and any ResourceObjs allocated
496 // inside the vframeArray (StackValueCollections)
498 delete thread->deopt_mark();
499 thread->set_deopt_mark(NULL);
500 thread->set_deopt_nmethod(NULL);
503 if (JvmtiExport::can_pop_frame()) {
504 #ifndef CC_INTERP
505 // Regardless of whether we entered this routine with the pending
506 // popframe condition bit set, we should always clear it now
507 thread->clear_popframe_condition();
508 #else
509 // C++ interpeter will clear has_pending_popframe when it enters
510 // with method_resume. For deopt_resume2 we clear it now.
511 if (thread->popframe_forcing_deopt_reexecution())
512 thread->clear_popframe_condition();
513 #endif /* CC_INTERP */
514 }
516 // unpack_frames() is called at the end of the deoptimization handler
517 // and (in C2) at the end of the uncommon trap handler. Note this fact
518 // so that an asynchronous stack walker can work again. This counter is
519 // incremented at the beginning of fetch_unroll_info() and (in C2) at
520 // the beginning of uncommon_trap().
521 thread->dec_in_deopt_handler();
522 }
525 // Return BasicType of value being returned
526 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
528 // We are already active int he special DeoptResourceMark any ResourceObj's we
529 // allocate will be freed at the end of the routine.
531 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
532 // but makes the entry a little slower. There is however a little dance we have to
533 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
534 ResetNoHandleMark rnhm; // No-op in release/product versions
535 HandleMark hm;
537 frame stub_frame = thread->last_frame();
539 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
540 // must point to the vframeArray for the unpack frame.
541 vframeArray* array = thread->vframe_array_head();
543 #ifndef PRODUCT
544 if (TraceDeoptimization) {
545 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
546 }
547 #endif
549 UnrollBlock* info = array->unroll_block();
551 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
552 array->unpack_to_stack(stub_frame, exec_mode);
554 BasicType bt = info->return_type();
556 // If we have an exception pending, claim that the return type is an oop
557 // so the deopt_blob does not overwrite the exception_oop.
559 if (exec_mode == Unpack_exception)
560 bt = T_OBJECT;
562 // Cleanup thread deopt data
563 cleanup_deopt_info(thread, array);
565 #ifndef PRODUCT
566 if (VerifyStack) {
567 ResourceMark res_mark;
569 // Verify that the just-unpacked frames match the interpreter's
570 // notions of expression stack and locals
571 vframeArray* cur_array = thread->vframe_array_last();
572 RegisterMap rm(thread, false);
573 rm.set_include_argument_oops(false);
574 bool is_top_frame = true;
575 int callee_size_of_parameters = 0;
576 int callee_max_locals = 0;
577 for (int i = 0; i < cur_array->frames(); i++) {
578 vframeArrayElement* el = cur_array->element(i);
579 frame* iframe = el->iframe();
580 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
582 // Get the oop map for this bci
583 InterpreterOopMap mask;
584 int cur_invoke_parameter_size = 0;
585 bool try_next_mask = false;
586 int next_mask_expression_stack_size = -1;
587 int top_frame_expression_stack_adjustment = 0;
588 methodHandle mh(thread, iframe->interpreter_frame_method());
589 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
590 BytecodeStream str(mh);
591 str.set_start(iframe->interpreter_frame_bci());
592 int max_bci = mh->code_size();
593 // Get to the next bytecode if possible
594 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
595 // Check to see if we can grab the number of outgoing arguments
596 // at an uncommon trap for an invoke (where the compiler
597 // generates debug info before the invoke has executed)
598 Bytecodes::Code cur_code = str.next();
599 if (cur_code == Bytecodes::_invokevirtual ||
600 cur_code == Bytecodes::_invokespecial ||
601 cur_code == Bytecodes::_invokestatic ||
602 cur_code == Bytecodes::_invokeinterface) {
603 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
604 symbolHandle signature(thread, invoke.signature());
605 ArgumentSizeComputer asc(signature);
606 cur_invoke_parameter_size = asc.size();
607 if (cur_code != Bytecodes::_invokestatic) {
608 // Add in receiver
609 ++cur_invoke_parameter_size;
610 }
611 }
612 if (str.bci() < max_bci) {
613 Bytecodes::Code bc = str.next();
614 if (bc >= 0) {
615 // The interpreter oop map generator reports results before
616 // the current bytecode has executed except in the case of
617 // calls. It seems to be hard to tell whether the compiler
618 // has emitted debug information matching the "state before"
619 // a given bytecode or the state after, so we try both
620 switch (cur_code) {
621 case Bytecodes::_invokevirtual:
622 case Bytecodes::_invokespecial:
623 case Bytecodes::_invokestatic:
624 case Bytecodes::_invokeinterface:
625 case Bytecodes::_athrow:
626 break;
627 default: {
628 InterpreterOopMap next_mask;
629 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
630 next_mask_expression_stack_size = next_mask.expression_stack_size();
631 // Need to subtract off the size of the result type of
632 // the bytecode because this is not described in the
633 // debug info but returned to the interpreter in the TOS
634 // caching register
635 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
636 if (bytecode_result_type != T_ILLEGAL) {
637 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
638 }
639 assert(top_frame_expression_stack_adjustment >= 0, "");
640 try_next_mask = true;
641 break;
642 }
643 }
644 }
645 }
647 // Verify stack depth and oops in frame
648 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
649 if (!(
650 /* SPARC */
651 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
652 /* x86 */
653 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
654 (try_next_mask &&
655 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
656 top_frame_expression_stack_adjustment))) ||
657 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
658 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
659 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
660 )) {
661 ttyLocker ttyl;
663 // Print out some information that will help us debug the problem
664 tty->print_cr("Wrong number of expression stack elements during deoptimization");
665 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
666 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
667 iframe->interpreter_frame_expression_stack_size());
668 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
669 tty->print_cr(" try_next_mask = %d", try_next_mask);
670 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
671 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
672 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
673 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
674 tty->print_cr(" exec_mode = %d", exec_mode);
675 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
676 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
677 tty->print_cr(" Interpreted frames:");
678 for (int k = 0; k < cur_array->frames(); k++) {
679 vframeArrayElement* el = cur_array->element(k);
680 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
681 }
682 cur_array->print_on_2(tty);
683 guarantee(false, "wrong number of expression stack elements during deopt");
684 }
685 VerifyOopClosure verify;
686 iframe->oops_interpreted_do(&verify, &rm, false);
687 callee_size_of_parameters = mh->size_of_parameters();
688 callee_max_locals = mh->max_locals();
689 is_top_frame = false;
690 }
691 }
692 #endif /* !PRODUCT */
695 return bt;
696 JRT_END
699 int Deoptimization::deoptimize_dependents() {
700 Threads::deoptimized_wrt_marked_nmethods();
701 return 0;
702 }
705 #ifdef COMPILER2
706 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
707 Handle pending_exception(thread->pending_exception());
708 const char* exception_file = thread->exception_file();
709 int exception_line = thread->exception_line();
710 thread->clear_pending_exception();
712 for (int i = 0; i < objects->length(); i++) {
713 assert(objects->at(i)->is_object(), "invalid debug information");
714 ObjectValue* sv = (ObjectValue*) objects->at(i);
716 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
717 oop obj = NULL;
719 if (k->oop_is_instance()) {
720 instanceKlass* ik = instanceKlass::cast(k());
721 obj = ik->allocate_instance(CHECK_(false));
722 } else if (k->oop_is_typeArray()) {
723 typeArrayKlass* ak = typeArrayKlass::cast(k());
724 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
725 int len = sv->field_size() / type2size[ak->element_type()];
726 obj = ak->allocate(len, CHECK_(false));
727 } else if (k->oop_is_objArray()) {
728 objArrayKlass* ak = objArrayKlass::cast(k());
729 obj = ak->allocate(sv->field_size(), CHECK_(false));
730 }
732 assert(obj != NULL, "allocation failed");
733 assert(sv->value().is_null(), "redundant reallocation");
734 sv->set_value(obj);
735 }
737 if (pending_exception.not_null()) {
738 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
739 }
741 return true;
742 }
744 // This assumes that the fields are stored in ObjectValue in the same order
745 // they are yielded by do_nonstatic_fields.
746 class FieldReassigner: public FieldClosure {
747 frame* _fr;
748 RegisterMap* _reg_map;
749 ObjectValue* _sv;
750 instanceKlass* _ik;
751 oop _obj;
753 int _i;
754 public:
755 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
756 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
758 int i() const { return _i; }
761 void do_field(fieldDescriptor* fd) {
762 intptr_t val;
763 StackValue* value =
764 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
765 int offset = fd->offset();
766 switch (fd->field_type()) {
767 case T_OBJECT: case T_ARRAY:
768 assert(value->type() == T_OBJECT, "Agreement.");
769 _obj->obj_field_put(offset, value->get_obj()());
770 break;
772 case T_LONG: case T_DOUBLE: {
773 assert(value->type() == T_INT, "Agreement.");
774 StackValue* low =
775 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
776 #ifdef _LP64
777 jlong res = (jlong)low->get_int();
778 #else
779 #ifdef SPARC
780 // For SPARC we have to swap high and low words.
781 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
782 #else
783 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
784 #endif //SPARC
785 #endif
786 _obj->long_field_put(offset, res);
787 break;
788 }
789 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
790 case T_INT: case T_FLOAT: // 4 bytes.
791 assert(value->type() == T_INT, "Agreement.");
792 val = value->get_int();
793 _obj->int_field_put(offset, (jint)*((jint*)&val));
794 break;
796 case T_SHORT: case T_CHAR: // 2 bytes
797 assert(value->type() == T_INT, "Agreement.");
798 val = value->get_int();
799 _obj->short_field_put(offset, (jshort)*((jint*)&val));
800 break;
802 case T_BOOLEAN: case T_BYTE: // 1 byte
803 assert(value->type() == T_INT, "Agreement.");
804 val = value->get_int();
805 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
806 break;
808 default:
809 ShouldNotReachHere();
810 }
811 _i++;
812 }
813 };
815 // restore elements of an eliminated type array
816 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
817 int index = 0;
818 intptr_t val;
820 for (int i = 0; i < sv->field_size(); i++) {
821 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
822 switch(type) {
823 case T_LONG: case T_DOUBLE: {
824 assert(value->type() == T_INT, "Agreement.");
825 StackValue* low =
826 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
827 #ifdef _LP64
828 jlong res = (jlong)low->get_int();
829 #else
830 #ifdef SPARC
831 // For SPARC we have to swap high and low words.
832 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
833 #else
834 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
835 #endif //SPARC
836 #endif
837 obj->long_at_put(index, res);
838 break;
839 }
841 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
842 case T_INT: case T_FLOAT: // 4 bytes.
843 assert(value->type() == T_INT, "Agreement.");
844 val = value->get_int();
845 obj->int_at_put(index, (jint)*((jint*)&val));
846 break;
848 case T_SHORT: case T_CHAR: // 2 bytes
849 assert(value->type() == T_INT, "Agreement.");
850 val = value->get_int();
851 obj->short_at_put(index, (jshort)*((jint*)&val));
852 break;
854 case T_BOOLEAN: case T_BYTE: // 1 byte
855 assert(value->type() == T_INT, "Agreement.");
856 val = value->get_int();
857 obj->bool_at_put(index, (jboolean)*((jint*)&val));
858 break;
860 default:
861 ShouldNotReachHere();
862 }
863 index++;
864 }
865 }
868 // restore fields of an eliminated object array
869 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
870 for (int i = 0; i < sv->field_size(); i++) {
871 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
872 assert(value->type() == T_OBJECT, "object element expected");
873 obj->obj_at_put(i, value->get_obj()());
874 }
875 }
878 // restore fields of all eliminated objects and arrays
879 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
880 for (int i = 0; i < objects->length(); i++) {
881 ObjectValue* sv = (ObjectValue*) objects->at(i);
882 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
883 Handle obj = sv->value();
884 assert(obj.not_null(), "reallocation was missed");
886 if (k->oop_is_instance()) {
887 instanceKlass* ik = instanceKlass::cast(k());
888 FieldReassigner reassign(fr, reg_map, sv, obj());
889 ik->do_nonstatic_fields(&reassign);
890 } else if (k->oop_is_typeArray()) {
891 typeArrayKlass* ak = typeArrayKlass::cast(k());
892 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
893 } else if (k->oop_is_objArray()) {
894 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
895 }
896 }
897 }
900 // relock objects for which synchronization was eliminated
901 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
902 for (int i = 0; i < monitors->length(); i++) {
903 MonitorInfo* mon_info = monitors->at(i);
904 if (mon_info->eliminated()) {
905 assert(mon_info->owner() != NULL, "reallocation was missed");
906 Handle obj = Handle(mon_info->owner());
907 markOop mark = obj->mark();
908 if (UseBiasedLocking && mark->has_bias_pattern()) {
909 // New allocated objects may have the mark set to anonymously biased.
910 // Also the deoptimized method may called methods with synchronization
911 // where the thread-local object is bias locked to the current thread.
912 assert(mark->is_biased_anonymously() ||
913 mark->biased_locker() == thread, "should be locked to current thread");
914 // Reset mark word to unbiased prototype.
915 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
916 obj->set_mark(unbiased_prototype);
917 }
918 BasicLock* lock = mon_info->lock();
919 ObjectSynchronizer::slow_enter(obj, lock, thread);
920 }
921 assert(mon_info->owner()->is_locked(), "object must be locked now");
922 }
923 }
926 #ifndef PRODUCT
927 // print information about reallocated objects
928 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
929 fieldDescriptor fd;
931 for (int i = 0; i < objects->length(); i++) {
932 ObjectValue* sv = (ObjectValue*) objects->at(i);
933 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
934 Handle obj = sv->value();
936 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
937 k->as_klassOop()->print_value();
938 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
939 tty->cr();
941 if (Verbose) {
942 k->oop_print_on(obj(), tty);
943 }
944 }
945 }
946 #endif
947 #endif // COMPILER2
949 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
951 #ifndef PRODUCT
952 if (TraceDeoptimization) {
953 ttyLocker ttyl;
954 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
955 fr.print_on(tty);
956 tty->print_cr(" Virtual frames (innermost first):");
957 for (int index = 0; index < chunk->length(); index++) {
958 compiledVFrame* vf = chunk->at(index);
959 tty->print(" %2d - ", index);
960 vf->print_value();
961 int bci = chunk->at(index)->raw_bci();
962 const char* code_name;
963 if (bci == SynchronizationEntryBCI) {
964 code_name = "sync entry";
965 } else {
966 Bytecodes::Code code = vf->method()->code_at(bci);
967 code_name = Bytecodes::name(code);
968 }
969 tty->print(" - %s", code_name);
970 tty->print_cr(" @ bci %d ", bci);
971 if (Verbose) {
972 vf->print();
973 tty->cr();
974 }
975 }
976 }
977 #endif
979 // Register map for next frame (used for stack crawl). We capture
980 // the state of the deopt'ing frame's caller. Thus if we need to
981 // stuff a C2I adapter we can properly fill in the callee-save
982 // register locations.
983 frame caller = fr.sender(reg_map);
984 int frame_size = caller.sp() - fr.sp();
986 frame sender = caller;
988 // Since the Java thread being deoptimized will eventually adjust it's own stack,
989 // the vframeArray containing the unpacking information is allocated in the C heap.
990 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
991 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
993 // Compare the vframeArray to the collected vframes
994 assert(array->structural_compare(thread, chunk), "just checking");
995 Events::log("# vframes = %d", (intptr_t)chunk->length());
997 #ifndef PRODUCT
998 if (TraceDeoptimization) {
999 ttyLocker ttyl;
1000 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1001 }
1002 #endif // PRODUCT
1004 return array;
1005 }
1008 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1009 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1010 for (int i = 0; i < monitors->length(); i++) {
1011 MonitorInfo* mon_info = monitors->at(i);
1012 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1013 objects_to_revoke->append(Handle(mon_info->owner()));
1014 }
1015 }
1016 }
1019 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1020 if (!UseBiasedLocking) {
1021 return;
1022 }
1024 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1026 // Unfortunately we don't have a RegisterMap available in most of
1027 // the places we want to call this routine so we need to walk the
1028 // stack again to update the register map.
1029 if (map == NULL || !map->update_map()) {
1030 StackFrameStream sfs(thread, true);
1031 bool found = false;
1032 while (!found && !sfs.is_done()) {
1033 frame* cur = sfs.current();
1034 sfs.next();
1035 found = cur->id() == fr.id();
1036 }
1037 assert(found, "frame to be deoptimized not found on target thread's stack");
1038 map = sfs.register_map();
1039 }
1041 vframe* vf = vframe::new_vframe(&fr, map, thread);
1042 compiledVFrame* cvf = compiledVFrame::cast(vf);
1043 // Revoke monitors' biases in all scopes
1044 while (!cvf->is_top()) {
1045 collect_monitors(cvf, objects_to_revoke);
1046 cvf = compiledVFrame::cast(cvf->sender());
1047 }
1048 collect_monitors(cvf, objects_to_revoke);
1050 if (SafepointSynchronize::is_at_safepoint()) {
1051 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1052 } else {
1053 BiasedLocking::revoke(objects_to_revoke);
1054 }
1055 }
1058 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1059 if (!UseBiasedLocking) {
1060 return;
1061 }
1063 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1064 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1065 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1066 if (jt->has_last_Java_frame()) {
1067 StackFrameStream sfs(jt, true);
1068 while (!sfs.is_done()) {
1069 frame* cur = sfs.current();
1070 if (cb->contains(cur->pc())) {
1071 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1072 compiledVFrame* cvf = compiledVFrame::cast(vf);
1073 // Revoke monitors' biases in all scopes
1074 while (!cvf->is_top()) {
1075 collect_monitors(cvf, objects_to_revoke);
1076 cvf = compiledVFrame::cast(cvf->sender());
1077 }
1078 collect_monitors(cvf, objects_to_revoke);
1079 }
1080 sfs.next();
1081 }
1082 }
1083 }
1084 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1085 }
1088 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1089 assert(fr.can_be_deoptimized(), "checking frame type");
1091 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1093 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1095 // Patch the nmethod so that when execution returns to it we will
1096 // deopt the execution state and return to the interpreter.
1097 fr.deoptimize(thread);
1098 }
1100 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1101 // Deoptimize only if the frame comes from compile code.
1102 // Do not deoptimize the frame which is already patched
1103 // during the execution of the loops below.
1104 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1105 return;
1106 }
1107 ResourceMark rm;
1108 DeoptimizationMarker dm;
1109 if (UseBiasedLocking) {
1110 revoke_biases_of_monitors(thread, fr, map);
1111 }
1112 deoptimize_single_frame(thread, fr);
1114 }
1117 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1118 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1119 "can only deoptimize other thread at a safepoint");
1120 // Compute frame and register map based on thread and sp.
1121 RegisterMap reg_map(thread, UseBiasedLocking);
1122 frame fr = thread->last_frame();
1123 while (fr.id() != id) {
1124 fr = fr.sender(®_map);
1125 }
1126 deoptimize(thread, fr, ®_map);
1127 }
1130 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1131 if (thread == Thread::current()) {
1132 Deoptimization::deoptimize_frame_internal(thread, id);
1133 } else {
1134 VM_DeoptimizeFrame deopt(thread, id);
1135 VMThread::execute(&deopt);
1136 }
1137 }
1140 // JVMTI PopFrame support
1141 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1142 {
1143 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1144 }
1145 JRT_END
1148 #if defined(COMPILER2) || defined(SHARK)
1149 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1150 // in case of an unresolved klass entry, load the class.
1151 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1152 klassOop tk = constant_pool->klass_at(index, CHECK);
1153 return;
1154 }
1156 if (!constant_pool->tag_at(index).is_symbol()) return;
1158 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1159 symbolHandle symbol (THREAD, constant_pool->symbol_at(index));
1161 // class name?
1162 if (symbol->byte_at(0) != '(') {
1163 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1164 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1165 return;
1166 }
1168 // then it must be a signature!
1169 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1170 if (ss.is_object()) {
1171 symbolOop s = ss.as_symbol(CHECK);
1172 symbolHandle class_name (THREAD, s);
1173 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1174 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1175 }
1176 }
1177 }
1180 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1181 EXCEPTION_MARK;
1182 load_class_by_index(constant_pool, index, THREAD);
1183 if (HAS_PENDING_EXCEPTION) {
1184 // Exception happened during classloading. We ignore the exception here, since it
1185 // is going to be rethrown since the current activation is going to be deoptimzied and
1186 // the interpreter will re-execute the bytecode.
1187 CLEAR_PENDING_EXCEPTION;
1188 }
1189 }
1191 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1192 HandleMark hm;
1194 // uncommon_trap() is called at the beginning of the uncommon trap
1195 // handler. Note this fact before we start generating temporary frames
1196 // that can confuse an asynchronous stack walker. This counter is
1197 // decremented at the end of unpack_frames().
1198 thread->inc_in_deopt_handler();
1200 // We need to update the map if we have biased locking.
1201 RegisterMap reg_map(thread, UseBiasedLocking);
1202 frame stub_frame = thread->last_frame();
1203 frame fr = stub_frame.sender(®_map);
1204 // Make sure the calling nmethod is not getting deoptimized and removed
1205 // before we are done with it.
1206 nmethodLocker nl(fr.pc());
1208 {
1209 ResourceMark rm;
1211 // Revoke biases of any monitors in the frame to ensure we can migrate them
1212 revoke_biases_of_monitors(thread, fr, ®_map);
1214 DeoptReason reason = trap_request_reason(trap_request);
1215 DeoptAction action = trap_request_action(trap_request);
1216 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1218 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1219 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1220 compiledVFrame* cvf = compiledVFrame::cast(vf);
1222 nmethod* nm = cvf->code();
1224 ScopeDesc* trap_scope = cvf->scope();
1225 methodHandle trap_method = trap_scope->method();
1226 int trap_bci = trap_scope->bci();
1227 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1229 // Record this event in the histogram.
1230 gather_statistics(reason, action, trap_bc);
1232 // Ensure that we can record deopt. history:
1233 bool create_if_missing = ProfileTraps;
1235 methodDataHandle trap_mdo
1236 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1238 // Print a bunch of diagnostics, if requested.
1239 if (TraceDeoptimization || LogCompilation) {
1240 ResourceMark rm;
1241 ttyLocker ttyl;
1242 char buf[100];
1243 if (xtty != NULL) {
1244 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1245 os::current_thread_id(),
1246 format_trap_request(buf, sizeof(buf), trap_request));
1247 nm->log_identity(xtty);
1248 }
1249 symbolHandle class_name;
1250 bool unresolved = false;
1251 if (unloaded_class_index >= 0) {
1252 constantPoolHandle constants (THREAD, trap_method->constants());
1253 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1254 class_name = symbolHandle(THREAD,
1255 constants->klass_name_at(unloaded_class_index));
1256 unresolved = true;
1257 if (xtty != NULL)
1258 xtty->print(" unresolved='1'");
1259 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1260 class_name = symbolHandle(THREAD,
1261 constants->symbol_at(unloaded_class_index));
1262 }
1263 if (xtty != NULL)
1264 xtty->name(class_name);
1265 }
1266 if (xtty != NULL && trap_mdo.not_null()) {
1267 // Dump the relevant MDO state.
1268 // This is the deopt count for the current reason, any previous
1269 // reasons or recompiles seen at this point.
1270 int dcnt = trap_mdo->trap_count(reason);
1271 if (dcnt != 0)
1272 xtty->print(" count='%d'", dcnt);
1273 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1274 int dos = (pdata == NULL)? 0: pdata->trap_state();
1275 if (dos != 0) {
1276 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1277 if (trap_state_is_recompiled(dos)) {
1278 int recnt2 = trap_mdo->overflow_recompile_count();
1279 if (recnt2 != 0)
1280 xtty->print(" recompiles2='%d'", recnt2);
1281 }
1282 }
1283 }
1284 if (xtty != NULL) {
1285 xtty->stamp();
1286 xtty->end_head();
1287 }
1288 if (TraceDeoptimization) { // make noise on the tty
1289 tty->print("Uncommon trap occurred in");
1290 nm->method()->print_short_name(tty);
1291 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1292 fr.pc(),
1293 (int) os::current_thread_id(),
1294 trap_reason_name(reason),
1295 trap_action_name(action),
1296 unloaded_class_index);
1297 if (class_name.not_null()) {
1298 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1299 class_name->print_symbol_on(tty);
1300 }
1301 tty->cr();
1302 }
1303 if (xtty != NULL) {
1304 // Log the precise location of the trap.
1305 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1306 xtty->begin_elem("jvms bci='%d'", sd->bci());
1307 xtty->method(sd->method());
1308 xtty->end_elem();
1309 if (sd->is_top()) break;
1310 }
1311 xtty->tail("uncommon_trap");
1312 }
1313 }
1314 // (End diagnostic printout.)
1316 // Load class if necessary
1317 if (unloaded_class_index >= 0) {
1318 constantPoolHandle constants(THREAD, trap_method->constants());
1319 load_class_by_index(constants, unloaded_class_index);
1320 }
1322 // Flush the nmethod if necessary and desirable.
1323 //
1324 // We need to avoid situations where we are re-flushing the nmethod
1325 // because of a hot deoptimization site. Repeated flushes at the same
1326 // point need to be detected by the compiler and avoided. If the compiler
1327 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1328 // module must take measures to avoid an infinite cycle of recompilation
1329 // and deoptimization. There are several such measures:
1330 //
1331 // 1. If a recompilation is ordered a second time at some site X
1332 // and for the same reason R, the action is adjusted to 'reinterpret',
1333 // to give the interpreter time to exercise the method more thoroughly.
1334 // If this happens, the method's overflow_recompile_count is incremented.
1335 //
1336 // 2. If the compiler fails to reduce the deoptimization rate, then
1337 // the method's overflow_recompile_count will begin to exceed the set
1338 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1339 // is adjusted to 'make_not_compilable', and the method is abandoned
1340 // to the interpreter. This is a performance hit for hot methods,
1341 // but is better than a disastrous infinite cycle of recompilations.
1342 // (Actually, only the method containing the site X is abandoned.)
1343 //
1344 // 3. In parallel with the previous measures, if the total number of
1345 // recompilations of a method exceeds the much larger set limit
1346 // PerMethodRecompilationCutoff, the method is abandoned.
1347 // This should only happen if the method is very large and has
1348 // many "lukewarm" deoptimizations. The code which enforces this
1349 // limit is elsewhere (class nmethod, class methodOopDesc).
1350 //
1351 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1352 // to recompile at each bytecode independently of the per-BCI cutoff.
1353 //
1354 // The decision to update code is up to the compiler, and is encoded
1355 // in the Action_xxx code. If the compiler requests Action_none
1356 // no trap state is changed, no compiled code is changed, and the
1357 // computation suffers along in the interpreter.
1358 //
1359 // The other action codes specify various tactics for decompilation
1360 // and recompilation. Action_maybe_recompile is the loosest, and
1361 // allows the compiled code to stay around until enough traps are seen,
1362 // and until the compiler gets around to recompiling the trapping method.
1363 //
1364 // The other actions cause immediate removal of the present code.
1366 bool update_trap_state = true;
1367 bool make_not_entrant = false;
1368 bool make_not_compilable = false;
1369 bool reprofile = false;
1370 switch (action) {
1371 case Action_none:
1372 // Keep the old code.
1373 update_trap_state = false;
1374 break;
1375 case Action_maybe_recompile:
1376 // Do not need to invalidate the present code, but we can
1377 // initiate another
1378 // Start compiler without (necessarily) invalidating the nmethod.
1379 // The system will tolerate the old code, but new code should be
1380 // generated when possible.
1381 break;
1382 case Action_reinterpret:
1383 // Go back into the interpreter for a while, and then consider
1384 // recompiling form scratch.
1385 make_not_entrant = true;
1386 // Reset invocation counter for outer most method.
1387 // This will allow the interpreter to exercise the bytecodes
1388 // for a while before recompiling.
1389 // By contrast, Action_make_not_entrant is immediate.
1390 //
1391 // Note that the compiler will track null_check, null_assert,
1392 // range_check, and class_check events and log them as if they
1393 // had been traps taken from compiled code. This will update
1394 // the MDO trap history so that the next compilation will
1395 // properly detect hot trap sites.
1396 reprofile = true;
1397 break;
1398 case Action_make_not_entrant:
1399 // Request immediate recompilation, and get rid of the old code.
1400 // Make them not entrant, so next time they are called they get
1401 // recompiled. Unloaded classes are loaded now so recompile before next
1402 // time they are called. Same for uninitialized. The interpreter will
1403 // link the missing class, if any.
1404 make_not_entrant = true;
1405 break;
1406 case Action_make_not_compilable:
1407 // Give up on compiling this method at all.
1408 make_not_entrant = true;
1409 make_not_compilable = true;
1410 break;
1411 default:
1412 ShouldNotReachHere();
1413 }
1415 // Setting +ProfileTraps fixes the following, on all platforms:
1416 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1417 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1418 // recompile relies on a methodDataOop to record heroic opt failures.
1420 // Whether the interpreter is producing MDO data or not, we also need
1421 // to use the MDO to detect hot deoptimization points and control
1422 // aggressive optimization.
1423 bool inc_recompile_count = false;
1424 ProfileData* pdata = NULL;
1425 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1426 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1427 uint this_trap_count = 0;
1428 bool maybe_prior_trap = false;
1429 bool maybe_prior_recompile = false;
1430 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1431 //outputs:
1432 this_trap_count,
1433 maybe_prior_trap,
1434 maybe_prior_recompile);
1435 // Because the interpreter also counts null, div0, range, and class
1436 // checks, these traps from compiled code are double-counted.
1437 // This is harmless; it just means that the PerXTrapLimit values
1438 // are in effect a little smaller than they look.
1440 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1441 if (per_bc_reason != Reason_none) {
1442 // Now take action based on the partially known per-BCI history.
1443 if (maybe_prior_trap
1444 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1445 // If there are too many traps at this BCI, force a recompile.
1446 // This will allow the compiler to see the limit overflow, and
1447 // take corrective action, if possible. The compiler generally
1448 // does not use the exact PerBytecodeTrapLimit value, but instead
1449 // changes its tactics if it sees any traps at all. This provides
1450 // a little hysteresis, delaying a recompile until a trap happens
1451 // several times.
1452 //
1453 // Actually, since there is only one bit of counter per BCI,
1454 // the possible per-BCI counts are {0,1,(per-method count)}.
1455 // This produces accurate results if in fact there is only
1456 // one hot trap site, but begins to get fuzzy if there are
1457 // many sites. For example, if there are ten sites each
1458 // trapping two or more times, they each get the blame for
1459 // all of their traps.
1460 make_not_entrant = true;
1461 }
1463 // Detect repeated recompilation at the same BCI, and enforce a limit.
1464 if (make_not_entrant && maybe_prior_recompile) {
1465 // More than one recompile at this point.
1466 inc_recompile_count = maybe_prior_trap;
1467 }
1468 } else {
1469 // For reasons which are not recorded per-bytecode, we simply
1470 // force recompiles unconditionally.
1471 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1472 make_not_entrant = true;
1473 }
1475 // Go back to the compiler if there are too many traps in this method.
1476 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1477 // If there are too many traps in this method, force a recompile.
1478 // This will allow the compiler to see the limit overflow, and
1479 // take corrective action, if possible.
1480 // (This condition is an unlikely backstop only, because the
1481 // PerBytecodeTrapLimit is more likely to take effect first,
1482 // if it is applicable.)
1483 make_not_entrant = true;
1484 }
1486 // Here's more hysteresis: If there has been a recompile at
1487 // this trap point already, run the method in the interpreter
1488 // for a while to exercise it more thoroughly.
1489 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1490 reprofile = true;
1491 }
1493 }
1495 // Take requested actions on the method:
1497 // Recompile
1498 if (make_not_entrant) {
1499 if (!nm->make_not_entrant()) {
1500 return; // the call did not change nmethod's state
1501 }
1503 if (pdata != NULL) {
1504 // Record the recompilation event, if any.
1505 int tstate0 = pdata->trap_state();
1506 int tstate1 = trap_state_set_recompiled(tstate0, true);
1507 if (tstate1 != tstate0)
1508 pdata->set_trap_state(tstate1);
1509 }
1510 }
1512 if (inc_recompile_count) {
1513 trap_mdo->inc_overflow_recompile_count();
1514 if ((uint)trap_mdo->overflow_recompile_count() >
1515 (uint)PerBytecodeRecompilationCutoff) {
1516 // Give up on the method containing the bad BCI.
1517 if (trap_method() == nm->method()) {
1518 make_not_compilable = true;
1519 } else {
1520 trap_method->set_not_compilable(CompLevel_full_optimization);
1521 // But give grace to the enclosing nm->method().
1522 }
1523 }
1524 }
1526 // Reprofile
1527 if (reprofile) {
1528 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1529 }
1531 // Give up compiling
1532 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1533 assert(make_not_entrant, "consistent");
1534 nm->method()->set_not_compilable(CompLevel_full_optimization);
1535 }
1537 } // Free marked resources
1539 }
1540 JRT_END
1542 methodDataOop
1543 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1544 bool create_if_missing) {
1545 Thread* THREAD = thread;
1546 methodDataOop mdo = m()->method_data();
1547 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1548 // Build an MDO. Ignore errors like OutOfMemory;
1549 // that simply means we won't have an MDO to update.
1550 methodOopDesc::build_interpreter_method_data(m, THREAD);
1551 if (HAS_PENDING_EXCEPTION) {
1552 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1553 CLEAR_PENDING_EXCEPTION;
1554 }
1555 mdo = m()->method_data();
1556 }
1557 return mdo;
1558 }
1560 ProfileData*
1561 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1562 int trap_bci,
1563 Deoptimization::DeoptReason reason,
1564 //outputs:
1565 uint& ret_this_trap_count,
1566 bool& ret_maybe_prior_trap,
1567 bool& ret_maybe_prior_recompile) {
1568 uint prior_trap_count = trap_mdo->trap_count(reason);
1569 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1571 // If the runtime cannot find a place to store trap history,
1572 // it is estimated based on the general condition of the method.
1573 // If the method has ever been recompiled, or has ever incurred
1574 // a trap with the present reason , then this BCI is assumed
1575 // (pessimistically) to be the culprit.
1576 bool maybe_prior_trap = (prior_trap_count != 0);
1577 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1578 ProfileData* pdata = NULL;
1581 // For reasons which are recorded per bytecode, we check per-BCI data.
1582 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1583 if (per_bc_reason != Reason_none) {
1584 // Find the profile data for this BCI. If there isn't one,
1585 // try to allocate one from the MDO's set of spares.
1586 // This will let us detect a repeated trap at this point.
1587 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1589 if (pdata != NULL) {
1590 // Query the trap state of this profile datum.
1591 int tstate0 = pdata->trap_state();
1592 if (!trap_state_has_reason(tstate0, per_bc_reason))
1593 maybe_prior_trap = false;
1594 if (!trap_state_is_recompiled(tstate0))
1595 maybe_prior_recompile = false;
1597 // Update the trap state of this profile datum.
1598 int tstate1 = tstate0;
1599 // Record the reason.
1600 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1601 // Store the updated state on the MDO, for next time.
1602 if (tstate1 != tstate0)
1603 pdata->set_trap_state(tstate1);
1604 } else {
1605 if (LogCompilation && xtty != NULL) {
1606 ttyLocker ttyl;
1607 // Missing MDP? Leave a small complaint in the log.
1608 xtty->elem("missing_mdp bci='%d'", trap_bci);
1609 }
1610 }
1611 }
1613 // Return results:
1614 ret_this_trap_count = this_trap_count;
1615 ret_maybe_prior_trap = maybe_prior_trap;
1616 ret_maybe_prior_recompile = maybe_prior_recompile;
1617 return pdata;
1618 }
1620 void
1621 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1622 ResourceMark rm;
1623 // Ignored outputs:
1624 uint ignore_this_trap_count;
1625 bool ignore_maybe_prior_trap;
1626 bool ignore_maybe_prior_recompile;
1627 query_update_method_data(trap_mdo, trap_bci,
1628 (DeoptReason)reason,
1629 ignore_this_trap_count,
1630 ignore_maybe_prior_trap,
1631 ignore_maybe_prior_recompile);
1632 }
1634 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1636 // Still in Java no safepoints
1637 {
1638 // This enters VM and may safepoint
1639 uncommon_trap_inner(thread, trap_request);
1640 }
1641 return fetch_unroll_info_helper(thread);
1642 }
1644 // Local derived constants.
1645 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1646 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1647 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1649 //---------------------------trap_state_reason---------------------------------
1650 Deoptimization::DeoptReason
1651 Deoptimization::trap_state_reason(int trap_state) {
1652 // This assert provides the link between the width of DataLayout::trap_bits
1653 // and the encoding of "recorded" reasons. It ensures there are enough
1654 // bits to store all needed reasons in the per-BCI MDO profile.
1655 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1656 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1657 trap_state -= recompile_bit;
1658 if (trap_state == DS_REASON_MASK) {
1659 return Reason_many;
1660 } else {
1661 assert((int)Reason_none == 0, "state=0 => Reason_none");
1662 return (DeoptReason)trap_state;
1663 }
1664 }
1665 //-------------------------trap_state_has_reason-------------------------------
1666 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1667 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1668 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1669 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1670 trap_state -= recompile_bit;
1671 if (trap_state == DS_REASON_MASK) {
1672 return -1; // true, unspecifically (bottom of state lattice)
1673 } else if (trap_state == reason) {
1674 return 1; // true, definitely
1675 } else if (trap_state == 0) {
1676 return 0; // false, definitely (top of state lattice)
1677 } else {
1678 return 0; // false, definitely
1679 }
1680 }
1681 //-------------------------trap_state_add_reason-------------------------------
1682 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1683 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1684 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1685 trap_state -= recompile_bit;
1686 if (trap_state == DS_REASON_MASK) {
1687 return trap_state + recompile_bit; // already at state lattice bottom
1688 } else if (trap_state == reason) {
1689 return trap_state + recompile_bit; // the condition is already true
1690 } else if (trap_state == 0) {
1691 return reason + recompile_bit; // no condition has yet been true
1692 } else {
1693 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1694 }
1695 }
1696 //-----------------------trap_state_is_recompiled------------------------------
1697 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1698 return (trap_state & DS_RECOMPILE_BIT) != 0;
1699 }
1700 //-----------------------trap_state_set_recompiled-----------------------------
1701 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1702 if (z) return trap_state | DS_RECOMPILE_BIT;
1703 else return trap_state & ~DS_RECOMPILE_BIT;
1704 }
1705 //---------------------------format_trap_state---------------------------------
1706 // This is used for debugging and diagnostics, including hotspot.log output.
1707 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1708 int trap_state) {
1709 DeoptReason reason = trap_state_reason(trap_state);
1710 bool recomp_flag = trap_state_is_recompiled(trap_state);
1711 // Re-encode the state from its decoded components.
1712 int decoded_state = 0;
1713 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1714 decoded_state = trap_state_add_reason(decoded_state, reason);
1715 if (recomp_flag)
1716 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1717 // If the state re-encodes properly, format it symbolically.
1718 // Because this routine is used for debugging and diagnostics,
1719 // be robust even if the state is a strange value.
1720 size_t len;
1721 if (decoded_state != trap_state) {
1722 // Random buggy state that doesn't decode??
1723 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1724 } else {
1725 len = jio_snprintf(buf, buflen, "%s%s",
1726 trap_reason_name(reason),
1727 recomp_flag ? " recompiled" : "");
1728 }
1729 if (len >= buflen)
1730 buf[buflen-1] = '\0';
1731 return buf;
1732 }
1735 //--------------------------------statics--------------------------------------
1736 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1737 = Deoptimization::Action_reinterpret;
1738 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1739 // Note: Keep this in sync. with enum DeoptReason.
1740 "none",
1741 "null_check",
1742 "null_assert",
1743 "range_check",
1744 "class_check",
1745 "array_check",
1746 "intrinsic",
1747 "bimorphic",
1748 "unloaded",
1749 "uninitialized",
1750 "unreached",
1751 "unhandled",
1752 "constraint",
1753 "div0_check",
1754 "age",
1755 "predicate"
1756 };
1757 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1758 // Note: Keep this in sync. with enum DeoptAction.
1759 "none",
1760 "maybe_recompile",
1761 "reinterpret",
1762 "make_not_entrant",
1763 "make_not_compilable"
1764 };
1766 const char* Deoptimization::trap_reason_name(int reason) {
1767 if (reason == Reason_many) return "many";
1768 if ((uint)reason < Reason_LIMIT)
1769 return _trap_reason_name[reason];
1770 static char buf[20];
1771 sprintf(buf, "reason%d", reason);
1772 return buf;
1773 }
1774 const char* Deoptimization::trap_action_name(int action) {
1775 if ((uint)action < Action_LIMIT)
1776 return _trap_action_name[action];
1777 static char buf[20];
1778 sprintf(buf, "action%d", action);
1779 return buf;
1780 }
1782 // This is used for debugging and diagnostics, including hotspot.log output.
1783 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1784 int trap_request) {
1785 jint unloaded_class_index = trap_request_index(trap_request);
1786 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1787 const char* action = trap_action_name(trap_request_action(trap_request));
1788 size_t len;
1789 if (unloaded_class_index < 0) {
1790 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1791 reason, action);
1792 } else {
1793 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1794 reason, action, unloaded_class_index);
1795 }
1796 if (len >= buflen)
1797 buf[buflen-1] = '\0';
1798 return buf;
1799 }
1801 juint Deoptimization::_deoptimization_hist
1802 [Deoptimization::Reason_LIMIT]
1803 [1 + Deoptimization::Action_LIMIT]
1804 [Deoptimization::BC_CASE_LIMIT]
1805 = {0};
1807 enum {
1808 LSB_BITS = 8,
1809 LSB_MASK = right_n_bits(LSB_BITS)
1810 };
1812 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1813 Bytecodes::Code bc) {
1814 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1815 assert(action >= 0 && action < Action_LIMIT, "oob");
1816 _deoptimization_hist[Reason_none][0][0] += 1; // total
1817 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1818 juint* cases = _deoptimization_hist[reason][1+action];
1819 juint* bc_counter_addr = NULL;
1820 juint bc_counter = 0;
1821 // Look for an unused counter, or an exact match to this BC.
1822 if (bc != Bytecodes::_illegal) {
1823 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1824 juint* counter_addr = &cases[bc_case];
1825 juint counter = *counter_addr;
1826 if ((counter == 0 && bc_counter_addr == NULL)
1827 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1828 // this counter is either free or is already devoted to this BC
1829 bc_counter_addr = counter_addr;
1830 bc_counter = counter | bc;
1831 }
1832 }
1833 }
1834 if (bc_counter_addr == NULL) {
1835 // Overflow, or no given bytecode.
1836 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1837 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1838 }
1839 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1840 }
1842 jint Deoptimization::total_deoptimization_count() {
1843 return _deoptimization_hist[Reason_none][0][0];
1844 }
1846 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1847 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1848 return _deoptimization_hist[reason][0][0];
1849 }
1851 void Deoptimization::print_statistics() {
1852 juint total = total_deoptimization_count();
1853 juint account = total;
1854 if (total != 0) {
1855 ttyLocker ttyl;
1856 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1857 tty->print_cr("Deoptimization traps recorded:");
1858 #define PRINT_STAT_LINE(name, r) \
1859 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1860 PRINT_STAT_LINE("total", total);
1861 // For each non-zero entry in the histogram, print the reason,
1862 // the action, and (if specifically known) the type of bytecode.
1863 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1864 for (int action = 0; action < Action_LIMIT; action++) {
1865 juint* cases = _deoptimization_hist[reason][1+action];
1866 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1867 juint counter = cases[bc_case];
1868 if (counter != 0) {
1869 char name[1*K];
1870 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1871 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1872 bc = Bytecodes::_illegal;
1873 sprintf(name, "%s/%s/%s",
1874 trap_reason_name(reason),
1875 trap_action_name(action),
1876 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1877 juint r = counter >> LSB_BITS;
1878 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1879 account -= r;
1880 }
1881 }
1882 }
1883 }
1884 if (account != 0) {
1885 PRINT_STAT_LINE("unaccounted", account);
1886 }
1887 #undef PRINT_STAT_LINE
1888 if (xtty != NULL) xtty->tail("statistics");
1889 }
1890 }
1891 #else // COMPILER2 || SHARK
1894 // Stubs for C1 only system.
1895 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1896 return false;
1897 }
1899 const char* Deoptimization::trap_reason_name(int reason) {
1900 return "unknown";
1901 }
1903 void Deoptimization::print_statistics() {
1904 // no output
1905 }
1907 void
1908 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1909 // no udpate
1910 }
1912 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1913 return 0;
1914 }
1916 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1917 Bytecodes::Code bc) {
1918 // no update
1919 }
1921 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1922 int trap_state) {
1923 jio_snprintf(buf, buflen, "#%d", trap_state);
1924 return buf;
1925 }
1927 #endif // COMPILER2 || SHARK