Tue, 08 Feb 2011 09:11:37 -0800
7017673: Remove setting of the sun.jkernel.DownloadManager as a boot classloader hook
Reviewed-by: alanb, dcubed, coleenp
1 /*
2 * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
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23 */
25 #include "precompiled.hpp"
26 #include "classfile/systemDictionary.hpp"
27 #include "code/debugInfoRec.hpp"
28 #include "code/nmethod.hpp"
29 #include "code/pcDesc.hpp"
30 #include "code/scopeDesc.hpp"
31 #include "interpreter/bytecode.hpp"
32 #include "interpreter/interpreter.hpp"
33 #include "interpreter/oopMapCache.hpp"
34 #include "memory/allocation.inline.hpp"
35 #include "memory/oopFactory.hpp"
36 #include "memory/resourceArea.hpp"
37 #include "oops/methodOop.hpp"
38 #include "oops/oop.inline.hpp"
39 #include "prims/jvmtiThreadState.hpp"
40 #include "runtime/biasedLocking.hpp"
41 #include "runtime/compilationPolicy.hpp"
42 #include "runtime/deoptimization.hpp"
43 #include "runtime/interfaceSupport.hpp"
44 #include "runtime/sharedRuntime.hpp"
45 #include "runtime/signature.hpp"
46 #include "runtime/stubRoutines.hpp"
47 #include "runtime/thread.hpp"
48 #include "runtime/vframe.hpp"
49 #include "runtime/vframeArray.hpp"
50 #include "runtime/vframe_hp.hpp"
51 #include "utilities/events.hpp"
52 #include "utilities/xmlstream.hpp"
53 #ifdef TARGET_ARCH_x86
54 # include "vmreg_x86.inline.hpp"
55 #endif
56 #ifdef TARGET_ARCH_sparc
57 # include "vmreg_sparc.inline.hpp"
58 #endif
59 #ifdef TARGET_ARCH_zero
60 # include "vmreg_zero.inline.hpp"
61 #endif
62 #ifdef TARGET_ARCH_arm
63 # include "vmreg_arm.inline.hpp"
64 #endif
65 #ifdef TARGET_ARCH_ppc
66 # include "vmreg_ppc.inline.hpp"
67 #endif
68 #ifdef COMPILER2
69 #ifdef TARGET_ARCH_MODEL_x86_32
70 # include "adfiles/ad_x86_32.hpp"
71 #endif
72 #ifdef TARGET_ARCH_MODEL_x86_64
73 # include "adfiles/ad_x86_64.hpp"
74 #endif
75 #ifdef TARGET_ARCH_MODEL_sparc
76 # include "adfiles/ad_sparc.hpp"
77 #endif
78 #ifdef TARGET_ARCH_MODEL_zero
79 # include "adfiles/ad_zero.hpp"
80 #endif
81 #ifdef TARGET_ARCH_MODEL_arm
82 # include "adfiles/ad_arm.hpp"
83 #endif
84 #ifdef TARGET_ARCH_MODEL_ppc
85 # include "adfiles/ad_ppc.hpp"
86 #endif
87 #endif
89 bool DeoptimizationMarker::_is_active = false;
91 Deoptimization::UnrollBlock::UnrollBlock(int size_of_deoptimized_frame,
92 int caller_adjustment,
93 int number_of_frames,
94 intptr_t* frame_sizes,
95 address* frame_pcs,
96 BasicType return_type) {
97 _size_of_deoptimized_frame = size_of_deoptimized_frame;
98 _caller_adjustment = caller_adjustment;
99 _number_of_frames = number_of_frames;
100 _frame_sizes = frame_sizes;
101 _frame_pcs = frame_pcs;
102 _register_block = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
103 _return_type = return_type;
104 // PD (x86 only)
105 _counter_temp = 0;
106 _initial_fp = 0;
107 _unpack_kind = 0;
108 _sender_sp_temp = 0;
110 _total_frame_sizes = size_of_frames();
111 }
114 Deoptimization::UnrollBlock::~UnrollBlock() {
115 FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
116 FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
117 FREE_C_HEAP_ARRAY(intptr_t, _register_block);
118 }
121 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
122 assert(register_number < RegisterMap::reg_count, "checking register number");
123 return &_register_block[register_number * 2];
124 }
128 int Deoptimization::UnrollBlock::size_of_frames() const {
129 // Acount first for the adjustment of the initial frame
130 int result = _caller_adjustment;
131 for (int index = 0; index < number_of_frames(); index++) {
132 result += frame_sizes()[index];
133 }
134 return result;
135 }
138 void Deoptimization::UnrollBlock::print() {
139 ttyLocker ttyl;
140 tty->print_cr("UnrollBlock");
141 tty->print_cr(" size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
142 tty->print( " frame_sizes: ");
143 for (int index = 0; index < number_of_frames(); index++) {
144 tty->print("%d ", frame_sizes()[index]);
145 }
146 tty->cr();
147 }
150 // In order to make fetch_unroll_info work properly with escape
151 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
152 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
153 // of previously eliminated objects occurs in realloc_objects, which is
154 // called from the method fetch_unroll_info_helper below.
155 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
156 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
157 // but makes the entry a little slower. There is however a little dance we have to
158 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
160 // fetch_unroll_info() is called at the beginning of the deoptimization
161 // handler. Note this fact before we start generating temporary frames
162 // that can confuse an asynchronous stack walker. This counter is
163 // decremented at the end of unpack_frames().
164 thread->inc_in_deopt_handler();
166 return fetch_unroll_info_helper(thread);
167 JRT_END
170 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
171 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
173 // Note: there is a safepoint safety issue here. No matter whether we enter
174 // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
175 // the vframeArray is created.
176 //
178 // Allocate our special deoptimization ResourceMark
179 DeoptResourceMark* dmark = new DeoptResourceMark(thread);
180 assert(thread->deopt_mark() == NULL, "Pending deopt!");
181 thread->set_deopt_mark(dmark);
183 frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
184 RegisterMap map(thread, true);
185 RegisterMap dummy_map(thread, false);
186 // Now get the deoptee with a valid map
187 frame deoptee = stub_frame.sender(&map);
188 // Set the deoptee nmethod
189 assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
190 thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
192 // Create a growable array of VFrames where each VFrame represents an inlined
193 // Java frame. This storage is allocated with the usual system arena.
194 assert(deoptee.is_compiled_frame(), "Wrong frame type");
195 GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
196 vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
197 while (!vf->is_top()) {
198 assert(vf->is_compiled_frame(), "Wrong frame type");
199 chunk->push(compiledVFrame::cast(vf));
200 vf = vf->sender();
201 }
202 assert(vf->is_compiled_frame(), "Wrong frame type");
203 chunk->push(compiledVFrame::cast(vf));
205 #ifdef COMPILER2
206 // Reallocate the non-escaping objects and restore their fields. Then
207 // relock objects if synchronization on them was eliminated.
208 if (DoEscapeAnalysis) {
209 if (EliminateAllocations) {
210 assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
211 GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
213 // The flag return_oop() indicates call sites which return oop
214 // in compiled code. Such sites include java method calls,
215 // runtime calls (for example, used to allocate new objects/arrays
216 // on slow code path) and any other calls generated in compiled code.
217 // It is not guaranteed that we can get such information here only
218 // by analyzing bytecode in deoptimized frames. This is why this flag
219 // is set during method compilation (see Compile::Process_OopMap_Node()).
220 bool save_oop_result = chunk->at(0)->scope()->return_oop();
221 Handle return_value;
222 if (save_oop_result) {
223 // Reallocation may trigger GC. If deoptimization happened on return from
224 // call which returns oop we need to save it since it is not in oopmap.
225 oop result = deoptee.saved_oop_result(&map);
226 assert(result == NULL || result->is_oop(), "must be oop");
227 return_value = Handle(thread, result);
228 assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
229 if (TraceDeoptimization) {
230 tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
231 }
232 }
233 bool reallocated = false;
234 if (objects != NULL) {
235 JRT_BLOCK
236 reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
237 JRT_END
238 }
239 if (reallocated) {
240 reassign_fields(&deoptee, &map, objects);
241 #ifndef PRODUCT
242 if (TraceDeoptimization) {
243 ttyLocker ttyl;
244 tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
245 print_objects(objects);
246 }
247 #endif
248 }
249 if (save_oop_result) {
250 // Restore result.
251 deoptee.set_saved_oop_result(&map, return_value());
252 }
253 }
254 if (EliminateLocks) {
255 #ifndef PRODUCT
256 bool first = true;
257 #endif
258 for (int i = 0; i < chunk->length(); i++) {
259 compiledVFrame* cvf = chunk->at(i);
260 assert (cvf->scope() != NULL,"expect only compiled java frames");
261 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
262 if (monitors->is_nonempty()) {
263 relock_objects(monitors, thread);
264 #ifndef PRODUCT
265 if (TraceDeoptimization) {
266 ttyLocker ttyl;
267 for (int j = 0; j < monitors->length(); j++) {
268 MonitorInfo* mi = monitors->at(j);
269 if (mi->eliminated()) {
270 if (first) {
271 first = false;
272 tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
273 }
274 tty->print_cr(" object <" INTPTR_FORMAT "> locked", mi->owner());
275 }
276 }
277 }
278 #endif
279 }
280 }
281 }
282 }
283 #endif // COMPILER2
284 // Ensure that no safepoint is taken after pointers have been stored
285 // in fields of rematerialized objects. If a safepoint occurs from here on
286 // out the java state residing in the vframeArray will be missed.
287 No_Safepoint_Verifier no_safepoint;
289 vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
291 assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
292 thread->set_vframe_array_head(array);
294 // Now that the vframeArray has been created if we have any deferred local writes
295 // added by jvmti then we can free up that structure as the data is now in the
296 // vframeArray
298 if (thread->deferred_locals() != NULL) {
299 GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
300 int i = 0;
301 do {
302 // Because of inlining we could have multiple vframes for a single frame
303 // and several of the vframes could have deferred writes. Find them all.
304 if (list->at(i)->id() == array->original().id()) {
305 jvmtiDeferredLocalVariableSet* dlv = list->at(i);
306 list->remove_at(i);
307 // individual jvmtiDeferredLocalVariableSet are CHeapObj's
308 delete dlv;
309 } else {
310 i++;
311 }
312 } while ( i < list->length() );
313 if (list->length() == 0) {
314 thread->set_deferred_locals(NULL);
315 // free the list and elements back to C heap.
316 delete list;
317 }
319 }
321 #ifndef SHARK
322 // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
323 CodeBlob* cb = stub_frame.cb();
324 // Verify we have the right vframeArray
325 assert(cb->frame_size() >= 0, "Unexpected frame size");
326 intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
328 // If the deopt call site is a MethodHandle invoke call site we have
329 // to adjust the unpack_sp.
330 nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
331 if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
332 unpack_sp = deoptee.unextended_sp();
334 #ifdef ASSERT
335 assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
336 Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
337 #endif
338 #else
339 intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
340 #endif // !SHARK
342 // This is a guarantee instead of an assert because if vframe doesn't match
343 // we will unpack the wrong deoptimized frame and wind up in strange places
344 // where it will be very difficult to figure out what went wrong. Better
345 // to die an early death here than some very obscure death later when the
346 // trail is cold.
347 // Note: on ia64 this guarantee can be fooled by frames with no memory stack
348 // in that it will fail to detect a problem when there is one. This needs
349 // more work in tiger timeframe.
350 guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
352 int number_of_frames = array->frames();
354 // Compute the vframes' sizes. Note that frame_sizes[] entries are ordered from outermost to innermost
355 // virtual activation, which is the reverse of the elements in the vframes array.
356 intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
357 // +1 because we always have an interpreter return address for the final slot.
358 address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
359 int callee_parameters = 0;
360 int callee_locals = 0;
361 int popframe_extra_args = 0;
362 // Create an interpreter return address for the stub to use as its return
363 // address so the skeletal frames are perfectly walkable
364 frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
366 // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
367 // activation be put back on the expression stack of the caller for reexecution
368 if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
369 popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
370 }
372 //
373 // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
374 // frame_sizes/frame_pcs[1] next oldest frame (int)
375 // frame_sizes/frame_pcs[n] youngest frame (int)
376 //
377 // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
378 // owns the space for the return address to it's caller). Confusing ain't it.
379 //
380 // The vframe array can address vframes with indices running from
381 // 0.._frames-1. Index 0 is the youngest frame and _frame - 1 is the oldest (root) frame.
382 // When we create the skeletal frames we need the oldest frame to be in the zero slot
383 // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
384 // so things look a little strange in this loop.
385 //
386 for (int index = 0; index < array->frames(); index++ ) {
387 // frame[number_of_frames - 1 ] = on_stack_size(youngest)
388 // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
389 // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
390 frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
391 callee_locals,
392 index == 0,
393 popframe_extra_args);
394 // This pc doesn't have to be perfect just good enough to identify the frame
395 // as interpreted so the skeleton frame will be walkable
396 // The correct pc will be set when the skeleton frame is completely filled out
397 // The final pc we store in the loop is wrong and will be overwritten below
398 frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
400 callee_parameters = array->element(index)->method()->size_of_parameters();
401 callee_locals = array->element(index)->method()->max_locals();
402 popframe_extra_args = 0;
403 }
405 // Compute whether the root vframe returns a float or double value.
406 BasicType return_type;
407 {
408 HandleMark hm;
409 methodHandle method(thread, array->element(0)->method());
410 Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
411 return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
412 }
414 // Compute information for handling adapters and adjusting the frame size of the caller.
415 int caller_adjustment = 0;
417 // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
418 // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
419 // than simply use array->sender.pc(). This requires us to walk the current set of frames
420 //
421 frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
422 deopt_sender = deopt_sender.sender(&dummy_map); // Now deoptee caller
424 // Compute the amount the oldest interpreter frame will have to adjust
425 // its caller's stack by. If the caller is a compiled frame then
426 // we pretend that the callee has no parameters so that the
427 // extension counts for the full amount of locals and not just
428 // locals-parms. This is because without a c2i adapter the parm
429 // area as created by the compiled frame will not be usable by
430 // the interpreter. (Depending on the calling convention there
431 // may not even be enough space).
433 // QQQ I'd rather see this pushed down into last_frame_adjust
434 // and have it take the sender (aka caller).
436 if (deopt_sender.is_compiled_frame()) {
437 caller_adjustment = last_frame_adjust(0, callee_locals);
438 } else if (callee_locals > callee_parameters) {
439 // The caller frame may need extending to accommodate
440 // non-parameter locals of the first unpacked interpreted frame.
441 // Compute that adjustment.
442 caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
443 }
446 // If the sender is deoptimized the we must retrieve the address of the handler
447 // since the frame will "magically" show the original pc before the deopt
448 // and we'd undo the deopt.
450 frame_pcs[0] = deopt_sender.raw_pc();
452 #ifndef SHARK
453 assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
454 #endif // SHARK
456 UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
457 caller_adjustment * BytesPerWord,
458 number_of_frames,
459 frame_sizes,
460 frame_pcs,
461 return_type);
462 #if defined(IA32) || defined(AMD64)
463 // We need a way to pass fp to the unpacking code so the skeletal frames
464 // come out correct. This is only needed for x86 because of c2 using ebp
465 // as an allocatable register. So this update is useless (and harmless)
466 // on the other platforms. It would be nice to do this in a different
467 // way but even the old style deoptimization had a problem with deriving
468 // this value. NEEDS_CLEANUP
469 // Note: now that c1 is using c2's deopt blob we must do this on all
470 // x86 based platforms
471 intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
472 *fp_addr = array->sender().fp(); // was adapter_caller
473 #endif /* IA32 || AMD64 */
475 if (array->frames() > 1) {
476 if (VerifyStack && TraceDeoptimization) {
477 tty->print_cr("Deoptimizing method containing inlining");
478 }
479 }
481 array->set_unroll_block(info);
482 return info;
483 }
485 // Called to cleanup deoptimization data structures in normal case
486 // after unpacking to stack and when stack overflow error occurs
487 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
488 vframeArray *array) {
490 // Get array if coming from exception
491 if (array == NULL) {
492 array = thread->vframe_array_head();
493 }
494 thread->set_vframe_array_head(NULL);
496 // Free the previous UnrollBlock
497 vframeArray* old_array = thread->vframe_array_last();
498 thread->set_vframe_array_last(array);
500 if (old_array != NULL) {
501 UnrollBlock* old_info = old_array->unroll_block();
502 old_array->set_unroll_block(NULL);
503 delete old_info;
504 delete old_array;
505 }
507 // Deallocate any resource creating in this routine and any ResourceObjs allocated
508 // inside the vframeArray (StackValueCollections)
510 delete thread->deopt_mark();
511 thread->set_deopt_mark(NULL);
512 thread->set_deopt_nmethod(NULL);
515 if (JvmtiExport::can_pop_frame()) {
516 #ifndef CC_INTERP
517 // Regardless of whether we entered this routine with the pending
518 // popframe condition bit set, we should always clear it now
519 thread->clear_popframe_condition();
520 #else
521 // C++ interpeter will clear has_pending_popframe when it enters
522 // with method_resume. For deopt_resume2 we clear it now.
523 if (thread->popframe_forcing_deopt_reexecution())
524 thread->clear_popframe_condition();
525 #endif /* CC_INTERP */
526 }
528 // unpack_frames() is called at the end of the deoptimization handler
529 // and (in C2) at the end of the uncommon trap handler. Note this fact
530 // so that an asynchronous stack walker can work again. This counter is
531 // incremented at the beginning of fetch_unroll_info() and (in C2) at
532 // the beginning of uncommon_trap().
533 thread->dec_in_deopt_handler();
534 }
537 // Return BasicType of value being returned
538 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
540 // We are already active int he special DeoptResourceMark any ResourceObj's we
541 // allocate will be freed at the end of the routine.
543 // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
544 // but makes the entry a little slower. There is however a little dance we have to
545 // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
546 ResetNoHandleMark rnhm; // No-op in release/product versions
547 HandleMark hm;
549 frame stub_frame = thread->last_frame();
551 // Since the frame to unpack is the top frame of this thread, the vframe_array_head
552 // must point to the vframeArray for the unpack frame.
553 vframeArray* array = thread->vframe_array_head();
555 #ifndef PRODUCT
556 if (TraceDeoptimization) {
557 tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
558 }
559 #endif
561 UnrollBlock* info = array->unroll_block();
563 // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
564 array->unpack_to_stack(stub_frame, exec_mode);
566 BasicType bt = info->return_type();
568 // If we have an exception pending, claim that the return type is an oop
569 // so the deopt_blob does not overwrite the exception_oop.
571 if (exec_mode == Unpack_exception)
572 bt = T_OBJECT;
574 // Cleanup thread deopt data
575 cleanup_deopt_info(thread, array);
577 #ifndef PRODUCT
578 if (VerifyStack) {
579 ResourceMark res_mark;
581 // Verify that the just-unpacked frames match the interpreter's
582 // notions of expression stack and locals
583 vframeArray* cur_array = thread->vframe_array_last();
584 RegisterMap rm(thread, false);
585 rm.set_include_argument_oops(false);
586 bool is_top_frame = true;
587 int callee_size_of_parameters = 0;
588 int callee_max_locals = 0;
589 for (int i = 0; i < cur_array->frames(); i++) {
590 vframeArrayElement* el = cur_array->element(i);
591 frame* iframe = el->iframe();
592 guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
594 // Get the oop map for this bci
595 InterpreterOopMap mask;
596 int cur_invoke_parameter_size = 0;
597 bool try_next_mask = false;
598 int next_mask_expression_stack_size = -1;
599 int top_frame_expression_stack_adjustment = 0;
600 methodHandle mh(thread, iframe->interpreter_frame_method());
601 OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
602 BytecodeStream str(mh);
603 str.set_start(iframe->interpreter_frame_bci());
604 int max_bci = mh->code_size();
605 // Get to the next bytecode if possible
606 assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
607 // Check to see if we can grab the number of outgoing arguments
608 // at an uncommon trap for an invoke (where the compiler
609 // generates debug info before the invoke has executed)
610 Bytecodes::Code cur_code = str.next();
611 if (cur_code == Bytecodes::_invokevirtual ||
612 cur_code == Bytecodes::_invokespecial ||
613 cur_code == Bytecodes::_invokestatic ||
614 cur_code == Bytecodes::_invokeinterface) {
615 Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
616 Symbol* signature = invoke.signature();
617 ArgumentSizeComputer asc(signature);
618 cur_invoke_parameter_size = asc.size();
619 if (cur_code != Bytecodes::_invokestatic) {
620 // Add in receiver
621 ++cur_invoke_parameter_size;
622 }
623 }
624 if (str.bci() < max_bci) {
625 Bytecodes::Code bc = str.next();
626 if (bc >= 0) {
627 // The interpreter oop map generator reports results before
628 // the current bytecode has executed except in the case of
629 // calls. It seems to be hard to tell whether the compiler
630 // has emitted debug information matching the "state before"
631 // a given bytecode or the state after, so we try both
632 switch (cur_code) {
633 case Bytecodes::_invokevirtual:
634 case Bytecodes::_invokespecial:
635 case Bytecodes::_invokestatic:
636 case Bytecodes::_invokeinterface:
637 case Bytecodes::_athrow:
638 break;
639 default: {
640 InterpreterOopMap next_mask;
641 OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
642 next_mask_expression_stack_size = next_mask.expression_stack_size();
643 // Need to subtract off the size of the result type of
644 // the bytecode because this is not described in the
645 // debug info but returned to the interpreter in the TOS
646 // caching register
647 BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
648 if (bytecode_result_type != T_ILLEGAL) {
649 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
650 }
651 assert(top_frame_expression_stack_adjustment >= 0, "");
652 try_next_mask = true;
653 break;
654 }
655 }
656 }
657 }
659 // Verify stack depth and oops in frame
660 // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
661 if (!(
662 /* SPARC */
663 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
664 /* x86 */
665 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
666 (try_next_mask &&
667 (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
668 top_frame_expression_stack_adjustment))) ||
669 (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
670 (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
671 (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
672 )) {
673 ttyLocker ttyl;
675 // Print out some information that will help us debug the problem
676 tty->print_cr("Wrong number of expression stack elements during deoptimization");
677 tty->print_cr(" Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
678 tty->print_cr(" Fabricated interpreter frame had %d expression stack elements",
679 iframe->interpreter_frame_expression_stack_size());
680 tty->print_cr(" Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
681 tty->print_cr(" try_next_mask = %d", try_next_mask);
682 tty->print_cr(" next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
683 tty->print_cr(" callee_size_of_parameters = %d", callee_size_of_parameters);
684 tty->print_cr(" callee_max_locals = %d", callee_max_locals);
685 tty->print_cr(" top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
686 tty->print_cr(" exec_mode = %d", exec_mode);
687 tty->print_cr(" cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
688 tty->print_cr(" Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
689 tty->print_cr(" Interpreted frames:");
690 for (int k = 0; k < cur_array->frames(); k++) {
691 vframeArrayElement* el = cur_array->element(k);
692 tty->print_cr(" %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
693 }
694 cur_array->print_on_2(tty);
695 guarantee(false, "wrong number of expression stack elements during deopt");
696 }
697 VerifyOopClosure verify;
698 iframe->oops_interpreted_do(&verify, &rm, false);
699 callee_size_of_parameters = mh->size_of_parameters();
700 callee_max_locals = mh->max_locals();
701 is_top_frame = false;
702 }
703 }
704 #endif /* !PRODUCT */
707 return bt;
708 JRT_END
711 int Deoptimization::deoptimize_dependents() {
712 Threads::deoptimized_wrt_marked_nmethods();
713 return 0;
714 }
717 #ifdef COMPILER2
718 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
719 Handle pending_exception(thread->pending_exception());
720 const char* exception_file = thread->exception_file();
721 int exception_line = thread->exception_line();
722 thread->clear_pending_exception();
724 for (int i = 0; i < objects->length(); i++) {
725 assert(objects->at(i)->is_object(), "invalid debug information");
726 ObjectValue* sv = (ObjectValue*) objects->at(i);
728 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
729 oop obj = NULL;
731 if (k->oop_is_instance()) {
732 instanceKlass* ik = instanceKlass::cast(k());
733 obj = ik->allocate_instance(CHECK_(false));
734 } else if (k->oop_is_typeArray()) {
735 typeArrayKlass* ak = typeArrayKlass::cast(k());
736 assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
737 int len = sv->field_size() / type2size[ak->element_type()];
738 obj = ak->allocate(len, CHECK_(false));
739 } else if (k->oop_is_objArray()) {
740 objArrayKlass* ak = objArrayKlass::cast(k());
741 obj = ak->allocate(sv->field_size(), CHECK_(false));
742 }
744 assert(obj != NULL, "allocation failed");
745 assert(sv->value().is_null(), "redundant reallocation");
746 sv->set_value(obj);
747 }
749 if (pending_exception.not_null()) {
750 thread->set_pending_exception(pending_exception(), exception_file, exception_line);
751 }
753 return true;
754 }
756 // This assumes that the fields are stored in ObjectValue in the same order
757 // they are yielded by do_nonstatic_fields.
758 class FieldReassigner: public FieldClosure {
759 frame* _fr;
760 RegisterMap* _reg_map;
761 ObjectValue* _sv;
762 instanceKlass* _ik;
763 oop _obj;
765 int _i;
766 public:
767 FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
768 _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
770 int i() const { return _i; }
773 void do_field(fieldDescriptor* fd) {
774 intptr_t val;
775 StackValue* value =
776 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
777 int offset = fd->offset();
778 switch (fd->field_type()) {
779 case T_OBJECT: case T_ARRAY:
780 assert(value->type() == T_OBJECT, "Agreement.");
781 _obj->obj_field_put(offset, value->get_obj()());
782 break;
784 case T_LONG: case T_DOUBLE: {
785 assert(value->type() == T_INT, "Agreement.");
786 StackValue* low =
787 StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
788 #ifdef _LP64
789 jlong res = (jlong)low->get_int();
790 #else
791 #ifdef SPARC
792 // For SPARC we have to swap high and low words.
793 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
794 #else
795 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
796 #endif //SPARC
797 #endif
798 _obj->long_field_put(offset, res);
799 break;
800 }
801 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
802 case T_INT: case T_FLOAT: // 4 bytes.
803 assert(value->type() == T_INT, "Agreement.");
804 val = value->get_int();
805 _obj->int_field_put(offset, (jint)*((jint*)&val));
806 break;
808 case T_SHORT: case T_CHAR: // 2 bytes
809 assert(value->type() == T_INT, "Agreement.");
810 val = value->get_int();
811 _obj->short_field_put(offset, (jshort)*((jint*)&val));
812 break;
814 case T_BOOLEAN: case T_BYTE: // 1 byte
815 assert(value->type() == T_INT, "Agreement.");
816 val = value->get_int();
817 _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
818 break;
820 default:
821 ShouldNotReachHere();
822 }
823 _i++;
824 }
825 };
827 // restore elements of an eliminated type array
828 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
829 int index = 0;
830 intptr_t val;
832 for (int i = 0; i < sv->field_size(); i++) {
833 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
834 switch(type) {
835 case T_LONG: case T_DOUBLE: {
836 assert(value->type() == T_INT, "Agreement.");
837 StackValue* low =
838 StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
839 #ifdef _LP64
840 jlong res = (jlong)low->get_int();
841 #else
842 #ifdef SPARC
843 // For SPARC we have to swap high and low words.
844 jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
845 #else
846 jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
847 #endif //SPARC
848 #endif
849 obj->long_at_put(index, res);
850 break;
851 }
853 // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
854 case T_INT: case T_FLOAT: // 4 bytes.
855 assert(value->type() == T_INT, "Agreement.");
856 val = value->get_int();
857 obj->int_at_put(index, (jint)*((jint*)&val));
858 break;
860 case T_SHORT: case T_CHAR: // 2 bytes
861 assert(value->type() == T_INT, "Agreement.");
862 val = value->get_int();
863 obj->short_at_put(index, (jshort)*((jint*)&val));
864 break;
866 case T_BOOLEAN: case T_BYTE: // 1 byte
867 assert(value->type() == T_INT, "Agreement.");
868 val = value->get_int();
869 obj->bool_at_put(index, (jboolean)*((jint*)&val));
870 break;
872 default:
873 ShouldNotReachHere();
874 }
875 index++;
876 }
877 }
880 // restore fields of an eliminated object array
881 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
882 for (int i = 0; i < sv->field_size(); i++) {
883 StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
884 assert(value->type() == T_OBJECT, "object element expected");
885 obj->obj_at_put(i, value->get_obj()());
886 }
887 }
890 // restore fields of all eliminated objects and arrays
891 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
892 for (int i = 0; i < objects->length(); i++) {
893 ObjectValue* sv = (ObjectValue*) objects->at(i);
894 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
895 Handle obj = sv->value();
896 assert(obj.not_null(), "reallocation was missed");
898 if (k->oop_is_instance()) {
899 instanceKlass* ik = instanceKlass::cast(k());
900 FieldReassigner reassign(fr, reg_map, sv, obj());
901 ik->do_nonstatic_fields(&reassign);
902 } else if (k->oop_is_typeArray()) {
903 typeArrayKlass* ak = typeArrayKlass::cast(k());
904 reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
905 } else if (k->oop_is_objArray()) {
906 reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
907 }
908 }
909 }
912 // relock objects for which synchronization was eliminated
913 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
914 for (int i = 0; i < monitors->length(); i++) {
915 MonitorInfo* mon_info = monitors->at(i);
916 if (mon_info->eliminated()) {
917 assert(mon_info->owner() != NULL, "reallocation was missed");
918 Handle obj = Handle(mon_info->owner());
919 markOop mark = obj->mark();
920 if (UseBiasedLocking && mark->has_bias_pattern()) {
921 // New allocated objects may have the mark set to anonymously biased.
922 // Also the deoptimized method may called methods with synchronization
923 // where the thread-local object is bias locked to the current thread.
924 assert(mark->is_biased_anonymously() ||
925 mark->biased_locker() == thread, "should be locked to current thread");
926 // Reset mark word to unbiased prototype.
927 markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
928 obj->set_mark(unbiased_prototype);
929 }
930 BasicLock* lock = mon_info->lock();
931 ObjectSynchronizer::slow_enter(obj, lock, thread);
932 }
933 assert(mon_info->owner()->is_locked(), "object must be locked now");
934 }
935 }
938 #ifndef PRODUCT
939 // print information about reallocated objects
940 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
941 fieldDescriptor fd;
943 for (int i = 0; i < objects->length(); i++) {
944 ObjectValue* sv = (ObjectValue*) objects->at(i);
945 KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
946 Handle obj = sv->value();
948 tty->print(" object <" INTPTR_FORMAT "> of type ", sv->value()());
949 k->as_klassOop()->print_value();
950 tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
951 tty->cr();
953 if (Verbose) {
954 k->oop_print_on(obj(), tty);
955 }
956 }
957 }
958 #endif
959 #endif // COMPILER2
961 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
963 #ifndef PRODUCT
964 if (TraceDeoptimization) {
965 ttyLocker ttyl;
966 tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
967 fr.print_on(tty);
968 tty->print_cr(" Virtual frames (innermost first):");
969 for (int index = 0; index < chunk->length(); index++) {
970 compiledVFrame* vf = chunk->at(index);
971 tty->print(" %2d - ", index);
972 vf->print_value();
973 int bci = chunk->at(index)->raw_bci();
974 const char* code_name;
975 if (bci == SynchronizationEntryBCI) {
976 code_name = "sync entry";
977 } else {
978 Bytecodes::Code code = vf->method()->code_at(bci);
979 code_name = Bytecodes::name(code);
980 }
981 tty->print(" - %s", code_name);
982 tty->print_cr(" @ bci %d ", bci);
983 if (Verbose) {
984 vf->print();
985 tty->cr();
986 }
987 }
988 }
989 #endif
991 // Register map for next frame (used for stack crawl). We capture
992 // the state of the deopt'ing frame's caller. Thus if we need to
993 // stuff a C2I adapter we can properly fill in the callee-save
994 // register locations.
995 frame caller = fr.sender(reg_map);
996 int frame_size = caller.sp() - fr.sp();
998 frame sender = caller;
1000 // Since the Java thread being deoptimized will eventually adjust it's own stack,
1001 // the vframeArray containing the unpacking information is allocated in the C heap.
1002 // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1003 vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1005 // Compare the vframeArray to the collected vframes
1006 assert(array->structural_compare(thread, chunk), "just checking");
1007 Events::log("# vframes = %d", (intptr_t)chunk->length());
1009 #ifndef PRODUCT
1010 if (TraceDeoptimization) {
1011 ttyLocker ttyl;
1012 tty->print_cr(" Created vframeArray " INTPTR_FORMAT, array);
1013 }
1014 #endif // PRODUCT
1016 return array;
1017 }
1020 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1021 GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1022 for (int i = 0; i < monitors->length(); i++) {
1023 MonitorInfo* mon_info = monitors->at(i);
1024 if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1025 objects_to_revoke->append(Handle(mon_info->owner()));
1026 }
1027 }
1028 }
1031 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1032 if (!UseBiasedLocking) {
1033 return;
1034 }
1036 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1038 // Unfortunately we don't have a RegisterMap available in most of
1039 // the places we want to call this routine so we need to walk the
1040 // stack again to update the register map.
1041 if (map == NULL || !map->update_map()) {
1042 StackFrameStream sfs(thread, true);
1043 bool found = false;
1044 while (!found && !sfs.is_done()) {
1045 frame* cur = sfs.current();
1046 sfs.next();
1047 found = cur->id() == fr.id();
1048 }
1049 assert(found, "frame to be deoptimized not found on target thread's stack");
1050 map = sfs.register_map();
1051 }
1053 vframe* vf = vframe::new_vframe(&fr, map, thread);
1054 compiledVFrame* cvf = compiledVFrame::cast(vf);
1055 // Revoke monitors' biases in all scopes
1056 while (!cvf->is_top()) {
1057 collect_monitors(cvf, objects_to_revoke);
1058 cvf = compiledVFrame::cast(cvf->sender());
1059 }
1060 collect_monitors(cvf, objects_to_revoke);
1062 if (SafepointSynchronize::is_at_safepoint()) {
1063 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1064 } else {
1065 BiasedLocking::revoke(objects_to_revoke);
1066 }
1067 }
1070 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1071 if (!UseBiasedLocking) {
1072 return;
1073 }
1075 assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1076 GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1077 for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1078 if (jt->has_last_Java_frame()) {
1079 StackFrameStream sfs(jt, true);
1080 while (!sfs.is_done()) {
1081 frame* cur = sfs.current();
1082 if (cb->contains(cur->pc())) {
1083 vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1084 compiledVFrame* cvf = compiledVFrame::cast(vf);
1085 // Revoke monitors' biases in all scopes
1086 while (!cvf->is_top()) {
1087 collect_monitors(cvf, objects_to_revoke);
1088 cvf = compiledVFrame::cast(cvf->sender());
1089 }
1090 collect_monitors(cvf, objects_to_revoke);
1091 }
1092 sfs.next();
1093 }
1094 }
1095 }
1096 BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1097 }
1100 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1101 assert(fr.can_be_deoptimized(), "checking frame type");
1103 gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1105 EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1107 // Patch the nmethod so that when execution returns to it we will
1108 // deopt the execution state and return to the interpreter.
1109 fr.deoptimize(thread);
1110 }
1112 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1113 // Deoptimize only if the frame comes from compile code.
1114 // Do not deoptimize the frame which is already patched
1115 // during the execution of the loops below.
1116 if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1117 return;
1118 }
1119 ResourceMark rm;
1120 DeoptimizationMarker dm;
1121 if (UseBiasedLocking) {
1122 revoke_biases_of_monitors(thread, fr, map);
1123 }
1124 deoptimize_single_frame(thread, fr);
1126 }
1129 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1130 assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1131 "can only deoptimize other thread at a safepoint");
1132 // Compute frame and register map based on thread and sp.
1133 RegisterMap reg_map(thread, UseBiasedLocking);
1134 frame fr = thread->last_frame();
1135 while (fr.id() != id) {
1136 fr = fr.sender(®_map);
1137 }
1138 deoptimize(thread, fr, ®_map);
1139 }
1142 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1143 if (thread == Thread::current()) {
1144 Deoptimization::deoptimize_frame_internal(thread, id);
1145 } else {
1146 VM_DeoptimizeFrame deopt(thread, id);
1147 VMThread::execute(&deopt);
1148 }
1149 }
1152 // JVMTI PopFrame support
1153 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1154 {
1155 thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1156 }
1157 JRT_END
1160 #if defined(COMPILER2) || defined(SHARK)
1161 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1162 // in case of an unresolved klass entry, load the class.
1163 if (constant_pool->tag_at(index).is_unresolved_klass()) {
1164 klassOop tk = constant_pool->klass_at(index, CHECK);
1165 return;
1166 }
1168 if (!constant_pool->tag_at(index).is_symbol()) return;
1170 Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1171 Symbol* symbol = constant_pool->symbol_at(index);
1173 // class name?
1174 if (symbol->byte_at(0) != '(') {
1175 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1176 SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1177 return;
1178 }
1180 // then it must be a signature!
1181 ResourceMark rm(THREAD);
1182 for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1183 if (ss.is_object()) {
1184 Symbol* class_name = ss.as_symbol(CHECK);
1185 Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1186 SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1187 }
1188 }
1189 }
1192 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1193 EXCEPTION_MARK;
1194 load_class_by_index(constant_pool, index, THREAD);
1195 if (HAS_PENDING_EXCEPTION) {
1196 // Exception happened during classloading. We ignore the exception here, since it
1197 // is going to be rethrown since the current activation is going to be deoptimzied and
1198 // the interpreter will re-execute the bytecode.
1199 CLEAR_PENDING_EXCEPTION;
1200 }
1201 }
1203 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1204 HandleMark hm;
1206 // uncommon_trap() is called at the beginning of the uncommon trap
1207 // handler. Note this fact before we start generating temporary frames
1208 // that can confuse an asynchronous stack walker. This counter is
1209 // decremented at the end of unpack_frames().
1210 thread->inc_in_deopt_handler();
1212 // We need to update the map if we have biased locking.
1213 RegisterMap reg_map(thread, UseBiasedLocking);
1214 frame stub_frame = thread->last_frame();
1215 frame fr = stub_frame.sender(®_map);
1216 // Make sure the calling nmethod is not getting deoptimized and removed
1217 // before we are done with it.
1218 nmethodLocker nl(fr.pc());
1220 {
1221 ResourceMark rm;
1223 // Revoke biases of any monitors in the frame to ensure we can migrate them
1224 revoke_biases_of_monitors(thread, fr, ®_map);
1226 DeoptReason reason = trap_request_reason(trap_request);
1227 DeoptAction action = trap_request_action(trap_request);
1228 jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1230 Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1231 vframe* vf = vframe::new_vframe(&fr, ®_map, thread);
1232 compiledVFrame* cvf = compiledVFrame::cast(vf);
1234 nmethod* nm = cvf->code();
1236 ScopeDesc* trap_scope = cvf->scope();
1237 methodHandle trap_method = trap_scope->method();
1238 int trap_bci = trap_scope->bci();
1239 Bytecodes::Code trap_bc = trap_method->java_code_at(trap_bci);
1241 // Record this event in the histogram.
1242 gather_statistics(reason, action, trap_bc);
1244 // Ensure that we can record deopt. history:
1245 bool create_if_missing = ProfileTraps;
1247 methodDataHandle trap_mdo
1248 (THREAD, get_method_data(thread, trap_method, create_if_missing));
1250 // Print a bunch of diagnostics, if requested.
1251 if (TraceDeoptimization || LogCompilation) {
1252 ResourceMark rm;
1253 ttyLocker ttyl;
1254 char buf[100];
1255 if (xtty != NULL) {
1256 xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1257 os::current_thread_id(),
1258 format_trap_request(buf, sizeof(buf), trap_request));
1259 nm->log_identity(xtty);
1260 }
1261 Symbol* class_name = NULL;
1262 bool unresolved = false;
1263 if (unloaded_class_index >= 0) {
1264 constantPoolHandle constants (THREAD, trap_method->constants());
1265 if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1266 class_name = constants->klass_name_at(unloaded_class_index);
1267 unresolved = true;
1268 if (xtty != NULL)
1269 xtty->print(" unresolved='1'");
1270 } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1271 class_name = constants->symbol_at(unloaded_class_index);
1272 }
1273 if (xtty != NULL)
1274 xtty->name(class_name);
1275 }
1276 if (xtty != NULL && trap_mdo.not_null()) {
1277 // Dump the relevant MDO state.
1278 // This is the deopt count for the current reason, any previous
1279 // reasons or recompiles seen at this point.
1280 int dcnt = trap_mdo->trap_count(reason);
1281 if (dcnt != 0)
1282 xtty->print(" count='%d'", dcnt);
1283 ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1284 int dos = (pdata == NULL)? 0: pdata->trap_state();
1285 if (dos != 0) {
1286 xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1287 if (trap_state_is_recompiled(dos)) {
1288 int recnt2 = trap_mdo->overflow_recompile_count();
1289 if (recnt2 != 0)
1290 xtty->print(" recompiles2='%d'", recnt2);
1291 }
1292 }
1293 }
1294 if (xtty != NULL) {
1295 xtty->stamp();
1296 xtty->end_head();
1297 }
1298 if (TraceDeoptimization) { // make noise on the tty
1299 tty->print("Uncommon trap occurred in");
1300 nm->method()->print_short_name(tty);
1301 tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1302 fr.pc(),
1303 (int) os::current_thread_id(),
1304 trap_reason_name(reason),
1305 trap_action_name(action),
1306 unloaded_class_index);
1307 if (class_name != NULL) {
1308 tty->print(unresolved ? " unresolved class: " : " symbol: ");
1309 class_name->print_symbol_on(tty);
1310 }
1311 tty->cr();
1312 }
1313 if (xtty != NULL) {
1314 // Log the precise location of the trap.
1315 for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1316 xtty->begin_elem("jvms bci='%d'", sd->bci());
1317 xtty->method(sd->method());
1318 xtty->end_elem();
1319 if (sd->is_top()) break;
1320 }
1321 xtty->tail("uncommon_trap");
1322 }
1323 }
1324 // (End diagnostic printout.)
1326 // Load class if necessary
1327 if (unloaded_class_index >= 0) {
1328 constantPoolHandle constants(THREAD, trap_method->constants());
1329 load_class_by_index(constants, unloaded_class_index);
1330 }
1332 // Flush the nmethod if necessary and desirable.
1333 //
1334 // We need to avoid situations where we are re-flushing the nmethod
1335 // because of a hot deoptimization site. Repeated flushes at the same
1336 // point need to be detected by the compiler and avoided. If the compiler
1337 // cannot avoid them (or has a bug and "refuses" to avoid them), this
1338 // module must take measures to avoid an infinite cycle of recompilation
1339 // and deoptimization. There are several such measures:
1340 //
1341 // 1. If a recompilation is ordered a second time at some site X
1342 // and for the same reason R, the action is adjusted to 'reinterpret',
1343 // to give the interpreter time to exercise the method more thoroughly.
1344 // If this happens, the method's overflow_recompile_count is incremented.
1345 //
1346 // 2. If the compiler fails to reduce the deoptimization rate, then
1347 // the method's overflow_recompile_count will begin to exceed the set
1348 // limit PerBytecodeRecompilationCutoff. If this happens, the action
1349 // is adjusted to 'make_not_compilable', and the method is abandoned
1350 // to the interpreter. This is a performance hit for hot methods,
1351 // but is better than a disastrous infinite cycle of recompilations.
1352 // (Actually, only the method containing the site X is abandoned.)
1353 //
1354 // 3. In parallel with the previous measures, if the total number of
1355 // recompilations of a method exceeds the much larger set limit
1356 // PerMethodRecompilationCutoff, the method is abandoned.
1357 // This should only happen if the method is very large and has
1358 // many "lukewarm" deoptimizations. The code which enforces this
1359 // limit is elsewhere (class nmethod, class methodOopDesc).
1360 //
1361 // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1362 // to recompile at each bytecode independently of the per-BCI cutoff.
1363 //
1364 // The decision to update code is up to the compiler, and is encoded
1365 // in the Action_xxx code. If the compiler requests Action_none
1366 // no trap state is changed, no compiled code is changed, and the
1367 // computation suffers along in the interpreter.
1368 //
1369 // The other action codes specify various tactics for decompilation
1370 // and recompilation. Action_maybe_recompile is the loosest, and
1371 // allows the compiled code to stay around until enough traps are seen,
1372 // and until the compiler gets around to recompiling the trapping method.
1373 //
1374 // The other actions cause immediate removal of the present code.
1376 bool update_trap_state = true;
1377 bool make_not_entrant = false;
1378 bool make_not_compilable = false;
1379 bool reprofile = false;
1380 switch (action) {
1381 case Action_none:
1382 // Keep the old code.
1383 update_trap_state = false;
1384 break;
1385 case Action_maybe_recompile:
1386 // Do not need to invalidate the present code, but we can
1387 // initiate another
1388 // Start compiler without (necessarily) invalidating the nmethod.
1389 // The system will tolerate the old code, but new code should be
1390 // generated when possible.
1391 break;
1392 case Action_reinterpret:
1393 // Go back into the interpreter for a while, and then consider
1394 // recompiling form scratch.
1395 make_not_entrant = true;
1396 // Reset invocation counter for outer most method.
1397 // This will allow the interpreter to exercise the bytecodes
1398 // for a while before recompiling.
1399 // By contrast, Action_make_not_entrant is immediate.
1400 //
1401 // Note that the compiler will track null_check, null_assert,
1402 // range_check, and class_check events and log them as if they
1403 // had been traps taken from compiled code. This will update
1404 // the MDO trap history so that the next compilation will
1405 // properly detect hot trap sites.
1406 reprofile = true;
1407 break;
1408 case Action_make_not_entrant:
1409 // Request immediate recompilation, and get rid of the old code.
1410 // Make them not entrant, so next time they are called they get
1411 // recompiled. Unloaded classes are loaded now so recompile before next
1412 // time they are called. Same for uninitialized. The interpreter will
1413 // link the missing class, if any.
1414 make_not_entrant = true;
1415 break;
1416 case Action_make_not_compilable:
1417 // Give up on compiling this method at all.
1418 make_not_entrant = true;
1419 make_not_compilable = true;
1420 break;
1421 default:
1422 ShouldNotReachHere();
1423 }
1425 // Setting +ProfileTraps fixes the following, on all platforms:
1426 // 4852688: ProfileInterpreter is off by default for ia64. The result is
1427 // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1428 // recompile relies on a methodDataOop to record heroic opt failures.
1430 // Whether the interpreter is producing MDO data or not, we also need
1431 // to use the MDO to detect hot deoptimization points and control
1432 // aggressive optimization.
1433 bool inc_recompile_count = false;
1434 ProfileData* pdata = NULL;
1435 if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1436 assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1437 uint this_trap_count = 0;
1438 bool maybe_prior_trap = false;
1439 bool maybe_prior_recompile = false;
1440 pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1441 //outputs:
1442 this_trap_count,
1443 maybe_prior_trap,
1444 maybe_prior_recompile);
1445 // Because the interpreter also counts null, div0, range, and class
1446 // checks, these traps from compiled code are double-counted.
1447 // This is harmless; it just means that the PerXTrapLimit values
1448 // are in effect a little smaller than they look.
1450 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1451 if (per_bc_reason != Reason_none) {
1452 // Now take action based on the partially known per-BCI history.
1453 if (maybe_prior_trap
1454 && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1455 // If there are too many traps at this BCI, force a recompile.
1456 // This will allow the compiler to see the limit overflow, and
1457 // take corrective action, if possible. The compiler generally
1458 // does not use the exact PerBytecodeTrapLimit value, but instead
1459 // changes its tactics if it sees any traps at all. This provides
1460 // a little hysteresis, delaying a recompile until a trap happens
1461 // several times.
1462 //
1463 // Actually, since there is only one bit of counter per BCI,
1464 // the possible per-BCI counts are {0,1,(per-method count)}.
1465 // This produces accurate results if in fact there is only
1466 // one hot trap site, but begins to get fuzzy if there are
1467 // many sites. For example, if there are ten sites each
1468 // trapping two or more times, they each get the blame for
1469 // all of their traps.
1470 make_not_entrant = true;
1471 }
1473 // Detect repeated recompilation at the same BCI, and enforce a limit.
1474 if (make_not_entrant && maybe_prior_recompile) {
1475 // More than one recompile at this point.
1476 inc_recompile_count = maybe_prior_trap;
1477 }
1478 } else {
1479 // For reasons which are not recorded per-bytecode, we simply
1480 // force recompiles unconditionally.
1481 // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1482 make_not_entrant = true;
1483 }
1485 // Go back to the compiler if there are too many traps in this method.
1486 if (this_trap_count >= (uint)PerMethodTrapLimit) {
1487 // If there are too many traps in this method, force a recompile.
1488 // This will allow the compiler to see the limit overflow, and
1489 // take corrective action, if possible.
1490 // (This condition is an unlikely backstop only, because the
1491 // PerBytecodeTrapLimit is more likely to take effect first,
1492 // if it is applicable.)
1493 make_not_entrant = true;
1494 }
1496 // Here's more hysteresis: If there has been a recompile at
1497 // this trap point already, run the method in the interpreter
1498 // for a while to exercise it more thoroughly.
1499 if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1500 reprofile = true;
1501 }
1503 }
1505 // Take requested actions on the method:
1507 // Recompile
1508 if (make_not_entrant) {
1509 if (!nm->make_not_entrant()) {
1510 return; // the call did not change nmethod's state
1511 }
1513 if (pdata != NULL) {
1514 // Record the recompilation event, if any.
1515 int tstate0 = pdata->trap_state();
1516 int tstate1 = trap_state_set_recompiled(tstate0, true);
1517 if (tstate1 != tstate0)
1518 pdata->set_trap_state(tstate1);
1519 }
1520 }
1522 if (inc_recompile_count) {
1523 trap_mdo->inc_overflow_recompile_count();
1524 if ((uint)trap_mdo->overflow_recompile_count() >
1525 (uint)PerBytecodeRecompilationCutoff) {
1526 // Give up on the method containing the bad BCI.
1527 if (trap_method() == nm->method()) {
1528 make_not_compilable = true;
1529 } else {
1530 trap_method->set_not_compilable(CompLevel_full_optimization);
1531 // But give grace to the enclosing nm->method().
1532 }
1533 }
1534 }
1536 // Reprofile
1537 if (reprofile) {
1538 CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1539 }
1541 // Give up compiling
1542 if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1543 assert(make_not_entrant, "consistent");
1544 nm->method()->set_not_compilable(CompLevel_full_optimization);
1545 }
1547 } // Free marked resources
1549 }
1550 JRT_END
1552 methodDataOop
1553 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1554 bool create_if_missing) {
1555 Thread* THREAD = thread;
1556 methodDataOop mdo = m()->method_data();
1557 if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1558 // Build an MDO. Ignore errors like OutOfMemory;
1559 // that simply means we won't have an MDO to update.
1560 methodOopDesc::build_interpreter_method_data(m, THREAD);
1561 if (HAS_PENDING_EXCEPTION) {
1562 assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1563 CLEAR_PENDING_EXCEPTION;
1564 }
1565 mdo = m()->method_data();
1566 }
1567 return mdo;
1568 }
1570 ProfileData*
1571 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1572 int trap_bci,
1573 Deoptimization::DeoptReason reason,
1574 //outputs:
1575 uint& ret_this_trap_count,
1576 bool& ret_maybe_prior_trap,
1577 bool& ret_maybe_prior_recompile) {
1578 uint prior_trap_count = trap_mdo->trap_count(reason);
1579 uint this_trap_count = trap_mdo->inc_trap_count(reason);
1581 // If the runtime cannot find a place to store trap history,
1582 // it is estimated based on the general condition of the method.
1583 // If the method has ever been recompiled, or has ever incurred
1584 // a trap with the present reason , then this BCI is assumed
1585 // (pessimistically) to be the culprit.
1586 bool maybe_prior_trap = (prior_trap_count != 0);
1587 bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1588 ProfileData* pdata = NULL;
1591 // For reasons which are recorded per bytecode, we check per-BCI data.
1592 DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1593 if (per_bc_reason != Reason_none) {
1594 // Find the profile data for this BCI. If there isn't one,
1595 // try to allocate one from the MDO's set of spares.
1596 // This will let us detect a repeated trap at this point.
1597 pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1599 if (pdata != NULL) {
1600 // Query the trap state of this profile datum.
1601 int tstate0 = pdata->trap_state();
1602 if (!trap_state_has_reason(tstate0, per_bc_reason))
1603 maybe_prior_trap = false;
1604 if (!trap_state_is_recompiled(tstate0))
1605 maybe_prior_recompile = false;
1607 // Update the trap state of this profile datum.
1608 int tstate1 = tstate0;
1609 // Record the reason.
1610 tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1611 // Store the updated state on the MDO, for next time.
1612 if (tstate1 != tstate0)
1613 pdata->set_trap_state(tstate1);
1614 } else {
1615 if (LogCompilation && xtty != NULL) {
1616 ttyLocker ttyl;
1617 // Missing MDP? Leave a small complaint in the log.
1618 xtty->elem("missing_mdp bci='%d'", trap_bci);
1619 }
1620 }
1621 }
1623 // Return results:
1624 ret_this_trap_count = this_trap_count;
1625 ret_maybe_prior_trap = maybe_prior_trap;
1626 ret_maybe_prior_recompile = maybe_prior_recompile;
1627 return pdata;
1628 }
1630 void
1631 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1632 ResourceMark rm;
1633 // Ignored outputs:
1634 uint ignore_this_trap_count;
1635 bool ignore_maybe_prior_trap;
1636 bool ignore_maybe_prior_recompile;
1637 query_update_method_data(trap_mdo, trap_bci,
1638 (DeoptReason)reason,
1639 ignore_this_trap_count,
1640 ignore_maybe_prior_trap,
1641 ignore_maybe_prior_recompile);
1642 }
1644 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1646 // Still in Java no safepoints
1647 {
1648 // This enters VM and may safepoint
1649 uncommon_trap_inner(thread, trap_request);
1650 }
1651 return fetch_unroll_info_helper(thread);
1652 }
1654 // Local derived constants.
1655 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1656 const int DS_REASON_MASK = DataLayout::trap_mask >> 1;
1657 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1659 //---------------------------trap_state_reason---------------------------------
1660 Deoptimization::DeoptReason
1661 Deoptimization::trap_state_reason(int trap_state) {
1662 // This assert provides the link between the width of DataLayout::trap_bits
1663 // and the encoding of "recorded" reasons. It ensures there are enough
1664 // bits to store all needed reasons in the per-BCI MDO profile.
1665 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1666 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1667 trap_state -= recompile_bit;
1668 if (trap_state == DS_REASON_MASK) {
1669 return Reason_many;
1670 } else {
1671 assert((int)Reason_none == 0, "state=0 => Reason_none");
1672 return (DeoptReason)trap_state;
1673 }
1674 }
1675 //-------------------------trap_state_has_reason-------------------------------
1676 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1677 assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1678 assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1679 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1680 trap_state -= recompile_bit;
1681 if (trap_state == DS_REASON_MASK) {
1682 return -1; // true, unspecifically (bottom of state lattice)
1683 } else if (trap_state == reason) {
1684 return 1; // true, definitely
1685 } else if (trap_state == 0) {
1686 return 0; // false, definitely (top of state lattice)
1687 } else {
1688 return 0; // false, definitely
1689 }
1690 }
1691 //-------------------------trap_state_add_reason-------------------------------
1692 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1693 assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1694 int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1695 trap_state -= recompile_bit;
1696 if (trap_state == DS_REASON_MASK) {
1697 return trap_state + recompile_bit; // already at state lattice bottom
1698 } else if (trap_state == reason) {
1699 return trap_state + recompile_bit; // the condition is already true
1700 } else if (trap_state == 0) {
1701 return reason + recompile_bit; // no condition has yet been true
1702 } else {
1703 return DS_REASON_MASK + recompile_bit; // fall to state lattice bottom
1704 }
1705 }
1706 //-----------------------trap_state_is_recompiled------------------------------
1707 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1708 return (trap_state & DS_RECOMPILE_BIT) != 0;
1709 }
1710 //-----------------------trap_state_set_recompiled-----------------------------
1711 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1712 if (z) return trap_state | DS_RECOMPILE_BIT;
1713 else return trap_state & ~DS_RECOMPILE_BIT;
1714 }
1715 //---------------------------format_trap_state---------------------------------
1716 // This is used for debugging and diagnostics, including hotspot.log output.
1717 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1718 int trap_state) {
1719 DeoptReason reason = trap_state_reason(trap_state);
1720 bool recomp_flag = trap_state_is_recompiled(trap_state);
1721 // Re-encode the state from its decoded components.
1722 int decoded_state = 0;
1723 if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1724 decoded_state = trap_state_add_reason(decoded_state, reason);
1725 if (recomp_flag)
1726 decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1727 // If the state re-encodes properly, format it symbolically.
1728 // Because this routine is used for debugging and diagnostics,
1729 // be robust even if the state is a strange value.
1730 size_t len;
1731 if (decoded_state != trap_state) {
1732 // Random buggy state that doesn't decode??
1733 len = jio_snprintf(buf, buflen, "#%d", trap_state);
1734 } else {
1735 len = jio_snprintf(buf, buflen, "%s%s",
1736 trap_reason_name(reason),
1737 recomp_flag ? " recompiled" : "");
1738 }
1739 if (len >= buflen)
1740 buf[buflen-1] = '\0';
1741 return buf;
1742 }
1745 //--------------------------------statics--------------------------------------
1746 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1747 = Deoptimization::Action_reinterpret;
1748 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1749 // Note: Keep this in sync. with enum DeoptReason.
1750 "none",
1751 "null_check",
1752 "null_assert",
1753 "range_check",
1754 "class_check",
1755 "array_check",
1756 "intrinsic",
1757 "bimorphic",
1758 "unloaded",
1759 "uninitialized",
1760 "unreached",
1761 "unhandled",
1762 "constraint",
1763 "div0_check",
1764 "age",
1765 "predicate"
1766 };
1767 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1768 // Note: Keep this in sync. with enum DeoptAction.
1769 "none",
1770 "maybe_recompile",
1771 "reinterpret",
1772 "make_not_entrant",
1773 "make_not_compilable"
1774 };
1776 const char* Deoptimization::trap_reason_name(int reason) {
1777 if (reason == Reason_many) return "many";
1778 if ((uint)reason < Reason_LIMIT)
1779 return _trap_reason_name[reason];
1780 static char buf[20];
1781 sprintf(buf, "reason%d", reason);
1782 return buf;
1783 }
1784 const char* Deoptimization::trap_action_name(int action) {
1785 if ((uint)action < Action_LIMIT)
1786 return _trap_action_name[action];
1787 static char buf[20];
1788 sprintf(buf, "action%d", action);
1789 return buf;
1790 }
1792 // This is used for debugging and diagnostics, including hotspot.log output.
1793 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1794 int trap_request) {
1795 jint unloaded_class_index = trap_request_index(trap_request);
1796 const char* reason = trap_reason_name(trap_request_reason(trap_request));
1797 const char* action = trap_action_name(trap_request_action(trap_request));
1798 size_t len;
1799 if (unloaded_class_index < 0) {
1800 len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1801 reason, action);
1802 } else {
1803 len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1804 reason, action, unloaded_class_index);
1805 }
1806 if (len >= buflen)
1807 buf[buflen-1] = '\0';
1808 return buf;
1809 }
1811 juint Deoptimization::_deoptimization_hist
1812 [Deoptimization::Reason_LIMIT]
1813 [1 + Deoptimization::Action_LIMIT]
1814 [Deoptimization::BC_CASE_LIMIT]
1815 = {0};
1817 enum {
1818 LSB_BITS = 8,
1819 LSB_MASK = right_n_bits(LSB_BITS)
1820 };
1822 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1823 Bytecodes::Code bc) {
1824 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1825 assert(action >= 0 && action < Action_LIMIT, "oob");
1826 _deoptimization_hist[Reason_none][0][0] += 1; // total
1827 _deoptimization_hist[reason][0][0] += 1; // per-reason total
1828 juint* cases = _deoptimization_hist[reason][1+action];
1829 juint* bc_counter_addr = NULL;
1830 juint bc_counter = 0;
1831 // Look for an unused counter, or an exact match to this BC.
1832 if (bc != Bytecodes::_illegal) {
1833 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1834 juint* counter_addr = &cases[bc_case];
1835 juint counter = *counter_addr;
1836 if ((counter == 0 && bc_counter_addr == NULL)
1837 || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1838 // this counter is either free or is already devoted to this BC
1839 bc_counter_addr = counter_addr;
1840 bc_counter = counter | bc;
1841 }
1842 }
1843 }
1844 if (bc_counter_addr == NULL) {
1845 // Overflow, or no given bytecode.
1846 bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1847 bc_counter = (*bc_counter_addr & ~LSB_MASK); // clear LSB
1848 }
1849 *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1850 }
1852 jint Deoptimization::total_deoptimization_count() {
1853 return _deoptimization_hist[Reason_none][0][0];
1854 }
1856 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1857 assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1858 return _deoptimization_hist[reason][0][0];
1859 }
1861 void Deoptimization::print_statistics() {
1862 juint total = total_deoptimization_count();
1863 juint account = total;
1864 if (total != 0) {
1865 ttyLocker ttyl;
1866 if (xtty != NULL) xtty->head("statistics type='deoptimization'");
1867 tty->print_cr("Deoptimization traps recorded:");
1868 #define PRINT_STAT_LINE(name, r) \
1869 tty->print_cr(" %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1870 PRINT_STAT_LINE("total", total);
1871 // For each non-zero entry in the histogram, print the reason,
1872 // the action, and (if specifically known) the type of bytecode.
1873 for (int reason = 0; reason < Reason_LIMIT; reason++) {
1874 for (int action = 0; action < Action_LIMIT; action++) {
1875 juint* cases = _deoptimization_hist[reason][1+action];
1876 for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1877 juint counter = cases[bc_case];
1878 if (counter != 0) {
1879 char name[1*K];
1880 Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1881 if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1882 bc = Bytecodes::_illegal;
1883 sprintf(name, "%s/%s/%s",
1884 trap_reason_name(reason),
1885 trap_action_name(action),
1886 Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1887 juint r = counter >> LSB_BITS;
1888 tty->print_cr(" %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1889 account -= r;
1890 }
1891 }
1892 }
1893 }
1894 if (account != 0) {
1895 PRINT_STAT_LINE("unaccounted", account);
1896 }
1897 #undef PRINT_STAT_LINE
1898 if (xtty != NULL) xtty->tail("statistics");
1899 }
1900 }
1901 #else // COMPILER2 || SHARK
1904 // Stubs for C1 only system.
1905 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1906 return false;
1907 }
1909 const char* Deoptimization::trap_reason_name(int reason) {
1910 return "unknown";
1911 }
1913 void Deoptimization::print_statistics() {
1914 // no output
1915 }
1917 void
1918 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1919 // no udpate
1920 }
1922 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1923 return 0;
1924 }
1926 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1927 Bytecodes::Code bc) {
1928 // no update
1929 }
1931 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1932 int trap_state) {
1933 jio_snprintf(buf, buflen, "#%d", trap_state);
1934 return buf;
1935 }
1937 #endif // COMPILER2 || SHARK