1 /*
   2  * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "code/codeCache.hpp"
  28 #include "code/debugInfoRec.hpp"
  29 #include "code/nmethod.hpp"
  30 #include "code/pcDesc.hpp"
  31 #include "code/scopeDesc.hpp"
  32 #include "interpreter/bytecode.hpp"
  33 #include "interpreter/interpreter.hpp"
  34 #include "interpreter/oopMapCache.hpp"
  35 #include "memory/allocation.inline.hpp"
  36 #include "memory/oopFactory.hpp"
  37 #include "memory/resourceArea.hpp"
  38 #include "oops/method.hpp"
  39 #include "oops/oop.inline.hpp"
  40 #include "oops/fieldStreams.hpp"
  41 #include "oops/verifyOopClosure.hpp"
  42 #include "prims/jvmtiThreadState.hpp"
  43 #include "runtime/biasedLocking.hpp"
  44 #include "runtime/compilationPolicy.hpp"
  45 #include "runtime/deoptimization.hpp"
  46 #include "runtime/interfaceSupport.hpp"
  47 #include "runtime/sharedRuntime.hpp"
  48 #include "runtime/signature.hpp"
  49 #include "runtime/stubRoutines.hpp"
  50 #include "runtime/thread.hpp"
  51 #include "runtime/vframe.hpp"
  52 #include "runtime/vframeArray.hpp"
  53 #include "runtime/vframe_hp.hpp"
  54 #include "utilities/events.hpp"
  55 #include "utilities/xmlstream.hpp"
  56 
  57 #if INCLUDE_JVMCI
  58 #include "jvmci/jvmciRuntime.hpp"
  59 #include "jvmci/jvmciJavaClasses.hpp"
  60 #endif
  61 
  62 
  63 bool DeoptimizationMarker::_is_active = false;
  64 
  65 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
  66                                          int  caller_adjustment,
  67                                          int  caller_actual_parameters,
  68                                          int  number_of_frames,
  69                                          intptr_t* frame_sizes,
  70                                          address* frame_pcs,
  71                                          BasicType return_type) {
  72   _size_of_deoptimized_frame = size_of_deoptimized_frame;
  73   _caller_adjustment         = caller_adjustment;
  74   _caller_actual_parameters  = caller_actual_parameters;
  75   _number_of_frames          = number_of_frames;
  76   _frame_sizes               = frame_sizes;
  77   _frame_pcs                 = frame_pcs;
  78   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
  79   _return_type               = return_type;
  80   _initial_info              = 0;
  81   // PD (x86 only)
  82   _counter_temp              = 0;
  83   _unpack_kind               = 0;
  84   _sender_sp_temp            = 0;
  85 
  86   _total_frame_sizes         = size_of_frames();
  87 }
  88 
  89 
  90 Deoptimization::UnrollBlock::~UnrollBlock() {
  91   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
  92   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
  93   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
  94 }
  95 
  96 
  97 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
  98   assert(register_number < RegisterMap::reg_count, "checking register number");
  99   return &_register_block[register_number * 2];
 100 }
 101 
 102 
 103 
 104 int Deoptimization::UnrollBlock::size_of_frames() const {
 105   // Acount first for the adjustment of the initial frame
 106   int result = _caller_adjustment;
 107   for (int index = 0; index < number_of_frames(); index++) {
 108     result += frame_sizes()[index];
 109   }
 110   return result;
 111 }
 112 
 113 
 114 void Deoptimization::UnrollBlock::print() {
 115   ttyLocker ttyl;
 116   tty->print_cr("UnrollBlock");
 117   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 118   tty->print(   "  frame_sizes: ");
 119   for (int index = 0; index < number_of_frames(); index++) {
 120     tty->print(INTX_FORMAT " ", frame_sizes()[index]);
 121   }
 122   tty->cr();
 123 }
 124 
 125 
 126 // In order to make fetch_unroll_info work properly with escape
 127 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
 128 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
 129 // of previously eliminated objects occurs in realloc_objects, which is
 130 // called from the method fetch_unroll_info_helper below.
 131 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
 132   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 133   // but makes the entry a little slower. There is however a little dance we have to
 134   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 135 
 136   // fetch_unroll_info() is called at the beginning of the deoptimization
 137   // handler. Note this fact before we start generating temporary frames
 138   // that can confuse an asynchronous stack walker. This counter is
 139   // decremented at the end of unpack_frames().
 140   if (TraceDeoptimization) {
 141     tty->print_cr("Deoptimizing thread " INTPTR_FORMAT, p2i(thread));
 142   }
 143   thread->inc_in_deopt_handler();
 144 
 145   return fetch_unroll_info_helper(thread);
 146 JRT_END
 147 
 148 
 149 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 150 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
 151 
 152   // Note: there is a safepoint safety issue here. No matter whether we enter
 153   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 154   // the vframeArray is created.
 155   //
 156 
 157   // Allocate our special deoptimization ResourceMark
 158   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
 159   assert(thread->deopt_mark() == NULL, "Pending deopt!");
 160   thread->set_deopt_mark(dmark);
 161 
 162   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
 163   RegisterMap map(thread, true);
 164   RegisterMap dummy_map(thread, false);
 165   // Now get the deoptee with a valid map
 166   frame deoptee = stub_frame.sender(&map);
 167   // Set the deoptee nmethod
 168   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
 169   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
 170   bool skip_internal = thread->deopt_nmethod() != NULL && !thread->deopt_nmethod()->compiler()->is_jvmci();
 171 
 172   if (VerifyStack) {
 173     thread->validate_frame_layout();
 174   }
 175 
 176   // Create a growable array of VFrames where each VFrame represents an inlined
 177   // Java frame.  This storage is allocated with the usual system arena.
 178   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 179   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 180   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
 181   while (!vf->is_top()) {
 182     assert(vf->is_compiled_frame(), "Wrong frame type");
 183     chunk->push(compiledVFrame::cast(vf));
 184     vf = vf->sender();
 185   }
 186   assert(vf->is_compiled_frame(), "Wrong frame type");
 187   chunk->push(compiledVFrame::cast(vf));
 188 
 189   bool realloc_failures = false;
 190 
 191 #if defined(COMPILER2) || INCLUDE_JVMCI
 192   // Reallocate the non-escaping objects and restore their fields. Then
 193   // relock objects if synchronization on them was eliminated.
 194 #ifndef INCLUDE_JVMCI
 195   if (DoEscapeAnalysis || EliminateNestedLocks) {
 196     if (EliminateAllocations) {
 197 #endif // INCLUDE_JVMCI
 198       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 199       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 200 
 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       // If the previous frame was popped, we don't have a result.
 209       bool save_oop_result = chunk->at(0)->scope()->return_oop() && !thread->popframe_forcing_deopt_reexecution();
 210       Handle return_value;
 211       if (save_oop_result) {
 212         // Reallocation may trigger GC. If deoptimization happened on return from
 213         // call which returns oop we need to save it since it is not in oopmap.
 214         oop result = deoptee.saved_oop_result(&map);
 215         assert(result == NULL || result->is_oop(), "must be oop");
 216         return_value = Handle(thread, result);
 217         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 218         if (TraceDeoptimization) {
 219           ttyLocker ttyl;
 220           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, p2i(result), p2i(thread));
 221         }
 222       }
 223       if (objects != NULL) {
 224         JRT_BLOCK
 225           realloc_failures = realloc_objects(thread, &deoptee, objects, THREAD);
 226         JRT_END
 227         reassign_fields(&deoptee, &map, objects, realloc_failures, skip_internal);
 228 #ifndef PRODUCT
 229         if (TraceDeoptimization) {
 230           ttyLocker ttyl;
 231           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 232           print_objects(objects, realloc_failures);
 233         }
 234 #endif
 235       }
 236       if (save_oop_result) {
 237         // Restore result.
 238         deoptee.set_saved_oop_result(&map, return_value());
 239       }
 240 #ifndef INCLUDE_JVMCI
 241     }
 242     if (EliminateLocks) {
 243 #endif // INCLUDE_JVMCI
 244 #ifndef PRODUCT
 245       bool first = true;
 246 #endif
 247       for (int i = 0; i < chunk->length(); i++) {
 248         compiledVFrame* cvf = chunk->at(i);
 249         assert (cvf->scope() != NULL,"expect only compiled java frames");
 250         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 251         if (monitors->is_nonempty()) {
 252           relock_objects(monitors, thread, realloc_failures);
 253 #ifndef PRODUCT
 254           if (PrintDeoptimizationDetails) {
 255             ttyLocker ttyl;
 256             for (int j = 0; j < monitors->length(); j++) {
 257               MonitorInfo* mi = monitors->at(j);
 258               if (mi->eliminated()) {
 259                 if (first) {
 260                   first = false;
 261                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, p2i(thread));
 262                 }
 263                 if (mi->owner_is_scalar_replaced()) {
 264                   Klass* k = java_lang_Class::as_Klass(mi->owner_klass());
 265                   tty->print_cr("     failed reallocation for klass %s", k->external_name());
 266                 } else {
 267                   tty->print_cr("     object <" INTPTR_FORMAT "> locked", p2i(mi->owner()));
 268                 }
 269               }
 270             }
 271           }
 272 #endif // !PRODUCT
 273         }
 274       }
 275 #ifndef INCLUDE_JVMCI
 276     }
 277   }
 278 #endif // INCLUDE_JVMCI
 279 #endif // COMPILER2 || INCLUDE_JVMCI
 280 
 281   // Ensure that no safepoint is taken after pointers have been stored
 282   // in fields of rematerialized objects.  If a safepoint occurs from here on
 283   // out the java state residing in the vframeArray will be missed.
 284   No_Safepoint_Verifier no_safepoint;
 285 
 286   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk, realloc_failures);
 287 #if defined(COMPILER2) || INCLUDE_JVMCI
 288   if (realloc_failures) {
 289     pop_frames_failed_reallocs(thread, array);
 290   }
 291 #endif
 292 
 293   assert(thread->vframe_array_head() == NULL, "Pending deopt!");
 294   thread->set_vframe_array_head(array);
 295 
 296   // Now that the vframeArray has been created if we have any deferred local writes
 297   // added by jvmti then we can free up that structure as the data is now in the
 298   // vframeArray
 299 
 300   if (thread->deferred_locals() != NULL) {
 301     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
 302     int i = 0;
 303     do {
 304       // Because of inlining we could have multiple vframes for a single frame
 305       // and several of the vframes could have deferred writes. Find them all.
 306       if (list->at(i)->id() == array->original().id()) {
 307         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
 308         list->remove_at(i);
 309         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
 310         delete dlv;
 311       } else {
 312         i++;
 313       }
 314     } while ( i < list->length() );
 315     if (list->length() == 0) {
 316       thread->set_deferred_locals(NULL);
 317       // free the list and elements back to C heap.
 318       delete list;
 319     }
 320 
 321   }
 322 
 323 #ifndef SHARK
 324   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 325   CodeBlob* cb = stub_frame.cb();
 326   // Verify we have the right vframeArray
 327   assert(cb->frame_size() >= 0, "Unexpected frame size");
 328   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 329 
 330   // If the deopt call site is a MethodHandle invoke call site we have
 331   // to adjust the unpack_sp.
 332   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 333   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 334     unpack_sp = deoptee.unextended_sp();
 335 
 336 #ifdef ASSERT
 337   assert(cb->is_deoptimization_stub() ||
 338          cb->is_uncommon_trap_stub() ||
 339          strcmp("Stub<DeoptimizationStub.deoptimizationHandler>", cb->name()) == 0 ||
 340          strcmp("Stub<UncommonTrapStub.uncommonTrapHandler>", cb->name()) == 0,
 341          "unexpected code blob: %s", cb->name());
 342 #endif
 343 #else
 344   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
 345 #endif // !SHARK
 346 
 347   // This is a guarantee instead of an assert because if vframe doesn't match
 348   // we will unpack the wrong deoptimized frame and wind up in strange places
 349   // where it will be very difficult to figure out what went wrong. Better
 350   // to die an early death here than some very obscure death later when the
 351   // trail is cold.
 352   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 353   // in that it will fail to detect a problem when there is one. This needs
 354   // more work in tiger timeframe.
 355   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 356 
 357   int number_of_frames = array->frames();
 358 
 359   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 360   // virtual activation, which is the reverse of the elements in the vframes array.
 361   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 362   // +1 because we always have an interpreter return address for the final slot.
 363   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 364   int popframe_extra_args = 0;
 365   // Create an interpreter return address for the stub to use as its return
 366   // address so the skeletal frames are perfectly walkable
 367   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 368 
 369   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 370   // activation be put back on the expression stack of the caller for reexecution
 371   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
 372     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
 373   }
 374 
 375   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 376   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 377   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 378   //
 379   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 380   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 381 
 382   // It's possible that the number of parameters at the call site is
 383   // different than number of arguments in the callee when method
 384   // handles are used.  If the caller is interpreted get the real
 385   // value so that the proper amount of space can be added to it's
 386   // frame.
 387   bool caller_was_method_handle = false;
 388   if (deopt_sender.is_interpreted_frame()) {
 389     methodHandle method = deopt_sender.interpreter_frame_method();
 390     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 391     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 392       // Method handle invokes may involve fairly arbitrary chains of
 393       // calls so it's impossible to know how much actual space the
 394       // caller has for locals.
 395       caller_was_method_handle = true;
 396     }
 397   }
 398 
 399   //
 400   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 401   // frame_sizes/frame_pcs[1] next oldest frame (int)
 402   // frame_sizes/frame_pcs[n] youngest frame (int)
 403   //
 404   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 405   // owns the space for the return address to it's caller).  Confusing ain't it.
 406   //
 407   // The vframe array can address vframes with indices running from
 408   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 409   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 410   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 411   // so things look a little strange in this loop.
 412   //
 413   int callee_parameters = 0;
 414   int callee_locals = 0;
 415   for (int index = 0; index < array->frames(); index++ ) {
 416     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 417     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 418     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 419     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 420                                                                                                     callee_locals,
 421                                                                                                     index == 0,
 422                                                                                                     popframe_extra_args);
 423     // This pc doesn't have to be perfect just good enough to identify the frame
 424     // as interpreted so the skeleton frame will be walkable
 425     // The correct pc will be set when the skeleton frame is completely filled out
 426     // The final pc we store in the loop is wrong and will be overwritten below
 427     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 428 
 429     callee_parameters = array->element(index)->method()->size_of_parameters();
 430     callee_locals = array->element(index)->method()->max_locals();
 431     popframe_extra_args = 0;
 432   }
 433 
 434   // Compute whether the root vframe returns a float or double value.
 435   BasicType return_type;
 436   {
 437     HandleMark hm;
 438     methodHandle method(thread, array->element(0)->method());
 439     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 440     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 441   }
 442 
 443   // Compute information for handling adapters and adjusting the frame size of the caller.
 444   int caller_adjustment = 0;
 445 
 446   // Compute the amount the oldest interpreter frame will have to adjust
 447   // its caller's stack by. If the caller is a compiled frame then
 448   // we pretend that the callee has no parameters so that the
 449   // extension counts for the full amount of locals and not just
 450   // locals-parms. This is because without a c2i adapter the parm
 451   // area as created by the compiled frame will not be usable by
 452   // the interpreter. (Depending on the calling convention there
 453   // may not even be enough space).
 454 
 455   // QQQ I'd rather see this pushed down into last_frame_adjust
 456   // and have it take the sender (aka caller).
 457 
 458   if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
 459     caller_adjustment = last_frame_adjust(0, callee_locals);
 460   } else if (callee_locals > callee_parameters) {
 461     // The caller frame may need extending to accommodate
 462     // non-parameter locals of the first unpacked interpreted frame.
 463     // Compute that adjustment.
 464     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 465   }
 466 
 467   // If the sender is deoptimized the we must retrieve the address of the handler
 468   // since the frame will "magically" show the original pc before the deopt
 469   // and we'd undo the deopt.
 470 
 471   frame_pcs[0] = deopt_sender.raw_pc();
 472 
 473 #ifndef SHARK
 474   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 475 #endif // SHARK
 476 
 477   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 478                                       caller_adjustment * BytesPerWord,
 479                                       caller_was_method_handle ? 0 : callee_parameters,
 480                                       number_of_frames,
 481                                       frame_sizes,
 482                                       frame_pcs,
 483                                       return_type);
 484   // On some platforms, we need a way to pass some platform dependent
 485   // information to the unpacking code so the skeletal frames come out
 486   // correct (initial fp value, unextended sp, ...)
 487   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 488 
 489   if (array->frames() > 1) {
 490     if (VerifyStack && TraceDeoptimization) {
 491       ttyLocker ttyl;
 492       tty->print_cr("Deoptimizing method containing inlining");
 493     }
 494   }
 495 
 496   array->set_unroll_block(info);
 497   return info;
 498 }
 499 
 500 // Called to cleanup deoptimization data structures in normal case
 501 // after unpacking to stack and when stack overflow error occurs
 502 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 503                                         vframeArray *array) {
 504 
 505   // Get array if coming from exception
 506   if (array == NULL) {
 507     array = thread->vframe_array_head();
 508   }
 509   thread->set_vframe_array_head(NULL);
 510 
 511   // Free the previous UnrollBlock
 512   vframeArray* old_array = thread->vframe_array_last();
 513   thread->set_vframe_array_last(array);
 514 
 515   if (old_array != NULL) {
 516     UnrollBlock* old_info = old_array->unroll_block();
 517     old_array->set_unroll_block(NULL);
 518     delete old_info;
 519     delete old_array;
 520   }
 521 
 522   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 523   // inside the vframeArray (StackValueCollections)
 524 
 525   delete thread->deopt_mark();
 526   thread->set_deopt_mark(NULL);
 527   thread->set_deopt_nmethod(NULL);
 528 
 529 
 530   if (JvmtiExport::can_pop_frame()) {
 531 #ifndef CC_INTERP
 532     // Regardless of whether we entered this routine with the pending
 533     // popframe condition bit set, we should always clear it now
 534     thread->clear_popframe_condition();
 535 #else
 536     // C++ interpreter will clear has_pending_popframe when it enters
 537     // with method_resume. For deopt_resume2 we clear it now.
 538     if (thread->popframe_forcing_deopt_reexecution())
 539         thread->clear_popframe_condition();
 540 #endif /* CC_INTERP */
 541   }
 542 
 543   // unpack_frames() is called at the end of the deoptimization handler
 544   // and (in C2) at the end of the uncommon trap handler. Note this fact
 545   // so that an asynchronous stack walker can work again. This counter is
 546   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 547   // the beginning of uncommon_trap().
 548   thread->dec_in_deopt_handler();
 549 }
 550 
 551 
 552 // Return BasicType of value being returned
 553 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 554 
 555   // We are already active int he special DeoptResourceMark any ResourceObj's we
 556   // allocate will be freed at the end of the routine.
 557 
 558   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 559   // but makes the entry a little slower. There is however a little dance we have to
 560   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 561   ResetNoHandleMark rnhm; // No-op in release/product versions
 562   HandleMark hm;
 563 
 564   frame stub_frame = thread->last_frame();
 565 
 566   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 567   // must point to the vframeArray for the unpack frame.
 568   vframeArray* array = thread->vframe_array_head();
 569 
 570 #ifndef PRODUCT
 571   if (TraceDeoptimization) {
 572     ttyLocker ttyl;
 573     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d",
 574                   p2i(thread), p2i(array), exec_mode);
 575   }
 576 #endif
 577   Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
 578               p2i(stub_frame.pc()), p2i(stub_frame.sp()), exec_mode);
 579 
 580   UnrollBlock* info = array->unroll_block();
 581 
 582   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 583   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 584 
 585   BasicType bt = info->return_type();
 586 
 587   // If we have an exception pending, claim that the return type is an oop
 588   // so the deopt_blob does not overwrite the exception_oop.
 589 
 590   if (exec_mode == Unpack_exception)
 591     bt = T_OBJECT;
 592 
 593   // Cleanup thread deopt data
 594   cleanup_deopt_info(thread, array);
 595 
 596 #ifndef PRODUCT
 597   if (VerifyStack) {
 598     ResourceMark res_mark;
 599 
 600     thread->validate_frame_layout();
 601 
 602     // Verify that the just-unpacked frames match the interpreter's
 603     // notions of expression stack and locals
 604     vframeArray* cur_array = thread->vframe_array_last();
 605     RegisterMap rm(thread, false);
 606     rm.set_include_argument_oops(false);
 607     bool is_top_frame = true;
 608     int callee_size_of_parameters = 0;
 609     int callee_max_locals = 0;
 610     for (int i = 0; i < cur_array->frames(); i++) {
 611       vframeArrayElement* el = cur_array->element(i);
 612       frame* iframe = el->iframe();
 613       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 614 
 615       // Get the oop map for this bci
 616       InterpreterOopMap mask;
 617       int cur_invoke_parameter_size = 0;
 618       bool try_next_mask = false;
 619       int next_mask_expression_stack_size = -1;
 620       int top_frame_expression_stack_adjustment = 0;
 621       methodHandle mh(thread, iframe->interpreter_frame_method());
 622       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 623       BytecodeStream str(mh);
 624       str.set_start(iframe->interpreter_frame_bci());
 625       int max_bci = mh->code_size();
 626       // Get to the next bytecode if possible
 627       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 628       // Check to see if we can grab the number of outgoing arguments
 629       // at an uncommon trap for an invoke (where the compiler
 630       // generates debug info before the invoke has executed)
 631       Bytecodes::Code cur_code = str.next();
 632       if (cur_code == Bytecodes::_invokevirtual   ||
 633           cur_code == Bytecodes::_invokespecial   ||
 634           cur_code == Bytecodes::_invokestatic    ||
 635           cur_code == Bytecodes::_invokeinterface ||
 636           cur_code == Bytecodes::_invokedynamic) {
 637         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 638         Symbol* signature = invoke.signature();
 639         ArgumentSizeComputer asc(signature);
 640         cur_invoke_parameter_size = asc.size();
 641         if (invoke.has_receiver()) {
 642           // Add in receiver
 643           ++cur_invoke_parameter_size;
 644         }
 645         if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
 646           callee_size_of_parameters++;
 647         }
 648       }
 649       if (str.bci() < max_bci) {
 650         Bytecodes::Code bc = str.next();
 651         if (bc >= 0) {
 652           // The interpreter oop map generator reports results before
 653           // the current bytecode has executed except in the case of
 654           // calls. It seems to be hard to tell whether the compiler
 655           // has emitted debug information matching the "state before"
 656           // a given bytecode or the state after, so we try both
 657           switch (cur_code) {
 658             case Bytecodes::_invokevirtual:
 659             case Bytecodes::_invokespecial:
 660             case Bytecodes::_invokestatic:
 661             case Bytecodes::_invokeinterface:
 662             case Bytecodes::_invokedynamic:
 663             case Bytecodes::_athrow:
 664               break;
 665             default: {
 666               InterpreterOopMap next_mask;
 667               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 668               next_mask_expression_stack_size = next_mask.expression_stack_size();
 669               // Need to subtract off the size of the result type of
 670               // the bytecode because this is not described in the
 671               // debug info but returned to the interpreter in the TOS
 672               // caching register
 673               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 674               if (bytecode_result_type != T_ILLEGAL) {
 675                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 676               }
 677               assert(top_frame_expression_stack_adjustment >= 0, "");
 678               try_next_mask = true;
 679               break;
 680             }
 681           }
 682         }
 683       }
 684 
 685       // Verify stack depth and oops in frame
 686       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 687       if (!(
 688             /* SPARC */
 689             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 690             /* x86 */
 691             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 692             (try_next_mask &&
 693              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 694                                                                     top_frame_expression_stack_adjustment))) ||
 695             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 696             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
 697              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 698             )) {
 699         ttyLocker ttyl;
 700 
 701         // Print out some information that will help us debug the problem
 702         tty->print_cr("Wrong number of expression stack elements during deoptimization");
 703         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 704         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 705                       iframe->interpreter_frame_expression_stack_size());
 706         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 707         tty->print_cr("  try_next_mask = %d", try_next_mask);
 708         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 709         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 710         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 711         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 712         tty->print_cr("  exec_mode = %d", exec_mode);
 713         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 714         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = %d", p2i(thread), thread->osthread()->thread_id());
 715         tty->print_cr("  Interpreted frames:");
 716         for (int k = 0; k < cur_array->frames(); k++) {
 717           vframeArrayElement* el = cur_array->element(k);
 718           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 719         }
 720         cur_array->print_on_2(tty);
 721         guarantee(false, "wrong number of expression stack elements during deopt");
 722       }
 723       VerifyOopClosure verify;
 724       iframe->oops_interpreted_do(&verify, NULL, &rm, false);
 725       callee_size_of_parameters = mh->size_of_parameters();
 726       callee_max_locals = mh->max_locals();
 727       is_top_frame = false;
 728     }
 729   }
 730 #endif /* !PRODUCT */
 731 
 732 
 733   return bt;
 734 JRT_END
 735 
 736 
 737 int Deoptimization::deoptimize_dependents() {
 738   Threads::deoptimized_wrt_marked_nmethods();
 739   return 0;
 740 }
 741 
 742 Deoptimization::DeoptAction Deoptimization::_unloaded_action
 743   = Deoptimization::Action_reinterpret;
 744 
 745 #if defined(COMPILER2) || INCLUDE_JVMCI
 746 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
 747   Handle pending_exception(thread->pending_exception());
 748   const char* exception_file = thread->exception_file();
 749   int exception_line = thread->exception_line();
 750   thread->clear_pending_exception();
 751 
 752   bool failures = false;
 753 
 754   for (int i = 0; i < objects->length(); i++) {
 755     assert(objects->at(i)->is_object(), "invalid debug information");
 756     ObjectValue* sv = (ObjectValue*) objects->at(i);
 757 
 758     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 759     oop obj = NULL;
 760 
 761     if (k->oop_is_instance()) {
 762       InstanceKlass* ik = InstanceKlass::cast(k());
 763       obj = ik->allocate_instance(THREAD);
 764     } else if (k->oop_is_typeArray()) {
 765       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 766       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
 767       int len = sv->field_size() / type2size[ak->element_type()];
 768       obj = ak->allocate(len, THREAD);
 769     } else if (k->oop_is_objArray()) {
 770       ObjArrayKlass* ak = ObjArrayKlass::cast(k());
 771       obj = ak->allocate(sv->field_size(), THREAD);
 772     }
 773 
 774     if (obj == NULL) {
 775       failures = true;
 776     }
 777 
 778     assert(sv->value().is_null(), "redundant reallocation");
 779     assert(obj != NULL || HAS_PENDING_EXCEPTION, "allocation should succeed or we should get an exception");
 780     CLEAR_PENDING_EXCEPTION;
 781     sv->set_value(obj);
 782   }
 783 
 784   if (failures) {
 785     THROW_OOP_(Universe::out_of_memory_error_realloc_objects(), failures);
 786   } else if (pending_exception.not_null()) {
 787     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
 788   }
 789 
 790   return failures;
 791 }
 792 
 793 // restore elements of an eliminated type array
 794 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
 795   int index = 0;
 796   intptr_t val;
 797 
 798   for (int i = 0; i < sv->field_size(); i++) {
 799     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 800     switch(type) {
 801     case T_LONG: case T_DOUBLE: {
 802       assert(value->type() == T_INT, "Agreement.");
 803       StackValue* low =
 804         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 805 #ifdef _LP64
 806       jlong res = (jlong)low->get_int();
 807 #else
 808 #ifdef SPARC
 809       // For SPARC we have to swap high and low words.
 810       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 811 #else
 812       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 813 #endif //SPARC
 814 #endif
 815       obj->long_at_put(index, res);
 816       break;
 817     }
 818 
 819     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 820     case T_INT: case T_FLOAT: { // 4 bytes.
 821       assert(value->type() == T_INT, "Agreement.");
 822       bool big_value = false;
 823       if (i + 1 < sv->field_size() && type == T_INT) {
 824         if (sv->field_at(i)->is_location()) {
 825           Location::Type type = ((LocationValue*) sv->field_at(i))->location().type();
 826           if (type == Location::dbl || type == Location::lng) {
 827             big_value = true;
 828           }
 829         } else if (sv->field_at(i)->is_constant_int()) {
 830           ScopeValue* next_scope_field = sv->field_at(i + 1);
 831           if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
 832             big_value = true;
 833           }
 834         }
 835       }
 836 
 837       if (big_value) {
 838         StackValue* low = 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->int_at_put(index, (jint)*((jint*)&res));
 850         obj->int_at_put(++index, (jint)*(((jint*)&res) + 1));
 851       } else {
 852         val = value->get_int();
 853         obj->int_at_put(index, (jint)*((jint*)&val));
 854       }
 855       break;
 856     }
 857 
 858     case T_SHORT: case T_CHAR: // 2 bytes
 859       assert(value->type() == T_INT, "Agreement.");
 860       val = value->get_int();
 861       obj->short_at_put(index, (jshort)*((jint*)&val));
 862       break;
 863 
 864     case T_BOOLEAN: case T_BYTE: // 1 byte
 865       assert(value->type() == T_INT, "Agreement.");
 866       val = value->get_int();
 867       obj->bool_at_put(index, (jboolean)*((jint*)&val));
 868       break;
 869 
 870       default:
 871         ShouldNotReachHere();
 872     }
 873     index++;
 874   }
 875 }
 876 
 877 
 878 // restore fields of an eliminated object array
 879 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
 880   for (int i = 0; i < sv->field_size(); i++) {
 881     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 882     assert(value->type() == T_OBJECT, "object element expected");
 883     obj->obj_at_put(i, value->get_obj()());
 884   }
 885 }
 886 
 887 class ReassignedField {
 888 public:
 889   int _offset;
 890   BasicType _type;
 891 public:
 892   ReassignedField() {
 893     _offset = 0;
 894     _type = T_ILLEGAL;
 895   }
 896 };
 897 
 898 int compare(ReassignedField* left, ReassignedField* right) {
 899   return left->_offset - right->_offset;
 900 }
 901 
 902 // Restore fields of an eliminated instance object using the same field order
 903 // returned by HotSpotResolvedObjectTypeImpl.getInstanceFields(true)
 904 static int reassign_fields_by_klass(InstanceKlass* klass, frame* fr, RegisterMap* reg_map, ObjectValue* sv, int svIndex, oop obj, bool skip_internal) {
 905   if (klass->superklass() != NULL) {
 906     svIndex = reassign_fields_by_klass(klass->superklass(), fr, reg_map, sv, svIndex, obj, skip_internal);
 907   }
 908 
 909   GrowableArray<ReassignedField>* fields = new GrowableArray<ReassignedField>();
 910   for (AllFieldStream fs(klass); !fs.done(); fs.next()) {
 911     if (!fs.access_flags().is_static() && (!skip_internal || !fs.access_flags().is_internal())) {
 912       ReassignedField field;
 913       field._offset = fs.offset();
 914       field._type = FieldType::basic_type(fs.signature());
 915       fields->append(field);
 916     }
 917   }
 918   fields->sort(compare);
 919   for (int i = 0; i < fields->length(); i++) {
 920     intptr_t val;
 921     ScopeValue* scope_field = sv->field_at(svIndex);
 922     StackValue* value = StackValue::create_stack_value(fr, reg_map, scope_field);
 923     int offset = fields->at(i)._offset;
 924     BasicType type = fields->at(i)._type;
 925     switch (type) {
 926       case T_OBJECT: case T_ARRAY:
 927         assert(value->type() == T_OBJECT, "Agreement.");
 928         obj->obj_field_put(offset, value->get_obj()());
 929         break;
 930 
 931       // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 932       case T_INT: case T_FLOAT: { // 4 bytes.
 933         assert(value->type() == T_INT, "Agreement.");
 934         bool big_value = false;
 935         if (i+1 < fields->length() && fields->at(i+1)._type == T_INT) {
 936           if (scope_field->is_location()) {
 937             Location::Type type = ((LocationValue*) scope_field)->location().type();
 938             if (type == Location::dbl || type == Location::lng) {
 939               big_value = true;
 940             }
 941           }
 942           if (scope_field->is_constant_int()) {
 943             ScopeValue* next_scope_field = sv->field_at(svIndex + 1);
 944             if (next_scope_field->is_constant_long() || next_scope_field->is_constant_double()) {
 945               big_value = true;
 946             }
 947           }
 948         }
 949 
 950         if (big_value) {
 951           i++;
 952           assert(i < fields->length(), "second T_INT field needed");
 953           assert(fields->at(i)._type == T_INT, "T_INT field needed");
 954         } else {
 955           val = value->get_int();
 956           obj->int_field_put(offset, (jint)*((jint*)&val));
 957           break;
 958         }
 959       }
 960         /* no break */
 961 
 962       case T_LONG: case T_DOUBLE: {
 963         assert(value->type() == T_INT, "Agreement.");
 964         StackValue* low = StackValue::create_stack_value(fr, reg_map, sv->field_at(++svIndex));
 965 #ifdef _LP64
 966         jlong res = (jlong)low->get_int();
 967 #else
 968 #ifdef SPARC
 969         // For SPARC we have to swap high and low words.
 970         jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 971 #else
 972         jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 973 #endif //SPARC
 974 #endif
 975         obj->long_field_put(offset, res);
 976         break;
 977       }
 978 
 979       case T_SHORT: case T_CHAR: // 2 bytes
 980         assert(value->type() == T_INT, "Agreement.");
 981         val = value->get_int();
 982         obj->short_field_put(offset, (jshort)*((jint*)&val));
 983         break;
 984 
 985       case T_BOOLEAN: case T_BYTE: // 1 byte
 986         assert(value->type() == T_INT, "Agreement.");
 987         val = value->get_int();
 988         obj->bool_field_put(offset, (jboolean)*((jint*)&val));
 989         break;
 990 
 991       default:
 992         ShouldNotReachHere();
 993     }
 994     svIndex++;
 995   }
 996   return svIndex;
 997 }
 998 
 999 // restore fields of all eliminated objects and arrays
1000 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects, bool realloc_failures, bool skip_internal) {
1001   for (int i = 0; i < objects->length(); i++) {
1002     ObjectValue* sv = (ObjectValue*) objects->at(i);
1003     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
1004     Handle obj = sv->value();
1005     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1006     if (PrintDeoptimizationDetails) {
1007       tty->print_cr("reassign fields for object of type %s!", k->name()->as_C_string());
1008     }
1009     if (obj.is_null()) {
1010       continue;
1011     }
1012 
1013     if (k->oop_is_instance()) {
1014       InstanceKlass* ik = InstanceKlass::cast(k());
1015       reassign_fields_by_klass(ik, fr, reg_map, sv, 0, obj(), skip_internal);
1016     } else if (k->oop_is_typeArray()) {
1017       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
1018       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
1019     } else if (k->oop_is_objArray()) {
1020       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
1021     }
1022   }
1023 }
1024 
1025 
1026 // relock objects for which synchronization was eliminated
1027 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread, bool realloc_failures) {
1028   for (int i = 0; i < monitors->length(); i++) {
1029     MonitorInfo* mon_info = monitors->at(i);
1030     if (mon_info->eliminated()) {
1031       assert(!mon_info->owner_is_scalar_replaced() || realloc_failures, "reallocation was missed");
1032       if (!mon_info->owner_is_scalar_replaced()) {
1033         Handle obj = Handle(mon_info->owner());
1034         markOop mark = obj->mark();
1035         if (UseBiasedLocking && mark->has_bias_pattern()) {
1036           // New allocated objects may have the mark set to anonymously biased.
1037           // Also the deoptimized method may called methods with synchronization
1038           // where the thread-local object is bias locked to the current thread.
1039           assert(mark->is_biased_anonymously() ||
1040                  mark->biased_locker() == thread, "should be locked to current thread");
1041           // Reset mark word to unbiased prototype.
1042           markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
1043           obj->set_mark(unbiased_prototype);
1044         }
1045         BasicLock* lock = mon_info->lock();
1046         ObjectSynchronizer::slow_enter(obj, lock, thread);
1047         assert(mon_info->owner()->is_locked(), "object must be locked now");
1048       }
1049     }
1050   }
1051 }
1052 
1053 
1054 #ifndef PRODUCT
1055 // print information about reallocated objects
1056 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects, bool realloc_failures) {
1057   fieldDescriptor fd;
1058 
1059   for (int i = 0; i < objects->length(); i++) {
1060     ObjectValue* sv = (ObjectValue*) objects->at(i);
1061     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
1062     Handle obj = sv->value();
1063 
1064     tty->print("     object <" INTPTR_FORMAT "> of type ", p2i(sv->value()()));
1065     k->print_value();
1066     assert(obj.not_null() || realloc_failures, "reallocation was missed");
1067     if (obj.is_null()) {
1068       tty->print(" allocation failed");
1069     } else {
1070       tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
1071     }
1072     tty->cr();
1073 
1074     if (Verbose && !obj.is_null()) {
1075       k->oop_print_on(obj(), tty);
1076     }
1077   }
1078 }
1079 #endif
1080 #endif // COMPILER2 || INCLUDE_JVMCI
1081 
1082 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk, bool realloc_failures) {
1083   Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, p2i(fr.pc()), p2i(fr.sp()));
1084 
1085 #ifndef PRODUCT
1086   if (PrintDeoptimizationDetails) {
1087     ttyLocker ttyl;
1088     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", p2i(thread));
1089     fr.print_on(tty);
1090     tty->print_cr("     Virtual frames (innermost first):");
1091     for (int index = 0; index < chunk->length(); index++) {
1092       compiledVFrame* vf = chunk->at(index);
1093       tty->print("       %2d - ", index);
1094       vf->print_value();
1095       int bci = chunk->at(index)->raw_bci();
1096       const char* code_name;
1097       if (bci == SynchronizationEntryBCI) {
1098         code_name = "sync entry";
1099       } else {
1100         Bytecodes::Code code = vf->method()->code_at(bci);
1101         code_name = Bytecodes::name(code);
1102       }
1103       tty->print(" - %s", code_name);
1104       tty->print_cr(" @ bci %d ", bci);
1105       if (Verbose) {
1106         vf->print();
1107         tty->cr();
1108       }
1109     }
1110   }
1111 #endif
1112 
1113   // Register map for next frame (used for stack crawl).  We capture
1114   // the state of the deopt'ing frame's caller.  Thus if we need to
1115   // stuff a C2I adapter we can properly fill in the callee-save
1116   // register locations.
1117   frame caller = fr.sender(reg_map);
1118   int frame_size = caller.sp() - fr.sp();
1119 
1120   frame sender = caller;
1121 
1122   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1123   // the vframeArray containing the unpacking information is allocated in the C heap.
1124   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1125   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr, realloc_failures);
1126 
1127   // Compare the vframeArray to the collected vframes
1128   assert(array->structural_compare(thread, chunk), "just checking");
1129 
1130 #ifndef PRODUCT
1131   if (PrintDeoptimizationDetails) {
1132     ttyLocker ttyl;
1133     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, p2i(array));
1134   }
1135 #endif // PRODUCT
1136 
1137   return array;
1138 }
1139 
1140 #if defined(COMPILER2) || INCLUDE_JVMCI
1141 void Deoptimization::pop_frames_failed_reallocs(JavaThread* thread, vframeArray* array) {
1142   // Reallocation of some scalar replaced objects failed. Record
1143   // that we need to pop all the interpreter frames for the
1144   // deoptimized compiled frame.
1145   assert(thread->frames_to_pop_failed_realloc() == 0, "missed frames to pop?");
1146   thread->set_frames_to_pop_failed_realloc(array->frames());
1147   // Unlock all monitors here otherwise the interpreter will see a
1148   // mix of locked and unlocked monitors (because of failed
1149   // reallocations of synchronized objects) and be confused.
1150   for (int i = 0; i < array->frames(); i++) {
1151     MonitorChunk* monitors = array->element(i)->monitors();
1152     if (monitors != NULL) {
1153       for (int j = 0; j < monitors->number_of_monitors(); j++) {
1154         BasicObjectLock* src = monitors->at(j);
1155         if (src->obj() != NULL) {
1156           ObjectSynchronizer::fast_exit(src->obj(), src->lock(), thread);
1157         }
1158       }
1159       array->element(i)->free_monitors(thread);
1160 #ifdef ASSERT
1161       array->element(i)->set_removed_monitors();
1162 #endif
1163     }
1164   }
1165 }
1166 #endif
1167 
1168 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1169   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1170   for (int i = 0; i < monitors->length(); i++) {
1171     MonitorInfo* mon_info = monitors->at(i);
1172     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1173       objects_to_revoke->append(Handle(mon_info->owner()));
1174     }
1175   }
1176 }
1177 
1178 
1179 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1180   if (!UseBiasedLocking) {
1181     return;
1182   }
1183 
1184   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1185 
1186   // Unfortunately we don't have a RegisterMap available in most of
1187   // the places we want to call this routine so we need to walk the
1188   // stack again to update the register map.
1189   if (map == NULL || !map->update_map()) {
1190     StackFrameStream sfs(thread, true);
1191     bool found = false;
1192     while (!found && !sfs.is_done()) {
1193       frame* cur = sfs.current();
1194       sfs.next();
1195       found = cur->id() == fr.id();
1196     }
1197     assert(found, "frame to be deoptimized not found on target thread's stack");
1198     map = sfs.register_map();
1199   }
1200 
1201   vframe* vf = vframe::new_vframe(&fr, map, thread);
1202   compiledVFrame* cvf = compiledVFrame::cast(vf);
1203   // Revoke monitors' biases in all scopes
1204   while (!cvf->is_top()) {
1205     collect_monitors(cvf, objects_to_revoke);
1206     cvf = compiledVFrame::cast(cvf->sender());
1207   }
1208   collect_monitors(cvf, objects_to_revoke);
1209 
1210   if (SafepointSynchronize::is_at_safepoint()) {
1211     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1212   } else {
1213     BiasedLocking::revoke(objects_to_revoke);
1214   }
1215 }
1216 
1217 
1218 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1219   if (!UseBiasedLocking) {
1220     return;
1221   }
1222 
1223   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1224   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1225   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1226     if (jt->has_last_Java_frame()) {
1227       StackFrameStream sfs(jt, true);
1228       while (!sfs.is_done()) {
1229         frame* cur = sfs.current();
1230         if (cb->contains(cur->pc())) {
1231           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1232           compiledVFrame* cvf = compiledVFrame::cast(vf);
1233           // Revoke monitors' biases in all scopes
1234           while (!cvf->is_top()) {
1235             collect_monitors(cvf, objects_to_revoke);
1236             cvf = compiledVFrame::cast(cvf->sender());
1237           }
1238           collect_monitors(cvf, objects_to_revoke);
1239         }
1240         sfs.next();
1241       }
1242     }
1243   }
1244   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1245 }
1246 
1247 
1248 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr, Deoptimization::DeoptReason reason) {
1249   assert(fr.can_be_deoptimized(), "checking frame type");
1250 
1251   gather_statistics(reason, Action_none, Bytecodes::_illegal);
1252 
1253   if (LogCompilation && xtty != NULL) {
1254     nmethod* nm = fr.cb()->as_nmethod_or_null();
1255     assert(nm != NULL, "only compiled methods can deopt");
1256 
1257     ttyLocker ttyl;
1258     xtty->begin_head("deoptimized thread='" UINTX_FORMAT "'", (uintx)thread->osthread()->thread_id());
1259     nm->log_identity(xtty);
1260     xtty->end_head();
1261     for (ScopeDesc* sd = nm->scope_desc_at(fr.pc()); ; sd = sd->sender()) {
1262       xtty->begin_elem("jvms bci='%d'", sd->bci());
1263       xtty->method(sd->method());
1264       xtty->end_elem();
1265       if (sd->is_top())  break;
1266     }
1267     xtty->tail("deoptimized");
1268   }
1269 
1270   // Patch the compiled method so that when execution returns to it we will
1271   // deopt the execution state and return to the interpreter.
1272   fr.deoptimize(thread);
1273 }
1274 
1275 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1276   deoptimize(thread, fr, map, Reason_constraint);
1277 }
1278 
1279 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map, DeoptReason reason) {
1280   // Deoptimize only if the frame comes from compile code.
1281   // Do not deoptimize the frame which is already patched
1282   // during the execution of the loops below.
1283   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1284     return;
1285   }
1286   ResourceMark rm;
1287   DeoptimizationMarker dm;
1288   if (UseBiasedLocking) {
1289     revoke_biases_of_monitors(thread, fr, map);
1290   }
1291   deoptimize_single_frame(thread, fr, reason);
1292 
1293 }
1294 
1295 
1296 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1297   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1298          "can only deoptimize other thread at a safepoint");
1299   // Compute frame and register map based on thread and sp.
1300   RegisterMap reg_map(thread, UseBiasedLocking);
1301   frame fr = thread->last_frame();
1302   while (fr.id() != id) {
1303     fr = fr.sender(&reg_map);
1304   }
1305   deoptimize(thread, fr, &reg_map, reason);
1306 }
1307 
1308 
1309 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id, DeoptReason reason) {
1310   if (thread == Thread::current()) {
1311     Deoptimization::deoptimize_frame_internal(thread, id, reason);
1312   } else {
1313     VM_DeoptimizeFrame deopt(thread, id, reason);
1314     VMThread::execute(&deopt);
1315   }
1316 }
1317 
1318 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1319   deoptimize_frame(thread, id, Reason_constraint);
1320 }
1321 
1322 // JVMTI PopFrame support
1323 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1324 {
1325   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1326 }
1327 JRT_END
1328 
1329 MethodData*
1330 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1331                                 bool create_if_missing) {
1332   Thread* THREAD = thread;
1333   MethodData* mdo = m()->method_data();
1334   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1335     // Build an MDO.  Ignore errors like OutOfMemory;
1336     // that simply means we won't have an MDO to update.
1337     Method::build_interpreter_method_data(m, THREAD);
1338     if (HAS_PENDING_EXCEPTION) {
1339       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1340       CLEAR_PENDING_EXCEPTION;
1341     }
1342     mdo = m()->method_data();
1343   }
1344   return mdo;
1345 }
1346 
1347 #if defined(COMPILER2) || defined(SHARK) || INCLUDE_JVMCI
1348 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1349   // in case of an unresolved klass entry, load the class.
1350   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1351     Klass* tk = constant_pool->klass_at_ignore_error(index, CHECK);
1352     return;
1353   }
1354 
1355   if (!constant_pool->tag_at(index).is_symbol()) return;
1356 
1357   Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1358   Symbol*  symbol  = constant_pool->symbol_at(index);
1359 
1360   // class name?
1361   if (symbol->byte_at(0) != '(') {
1362     Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1363     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1364     return;
1365   }
1366 
1367   // then it must be a signature!
1368   ResourceMark rm(THREAD);
1369   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1370     if (ss.is_object()) {
1371       Symbol* class_name = ss.as_symbol(CHECK);
1372       Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1373       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1374     }
1375   }
1376 }
1377 
1378 
1379 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1380   EXCEPTION_MARK;
1381   load_class_by_index(constant_pool, index, THREAD);
1382   if (HAS_PENDING_EXCEPTION) {
1383     // Exception happened during classloading. We ignore the exception here, since it
1384     // is going to be rethrown since the current activation is going to be deoptimized and
1385     // the interpreter will re-execute the bytecode.
1386     CLEAR_PENDING_EXCEPTION;
1387     // Class loading called java code which may have caused a stack
1388     // overflow. If the exception was thrown right before the return
1389     // to the runtime the stack is no longer guarded. Reguard the
1390     // stack otherwise if we return to the uncommon trap blob and the
1391     // stack bang causes a stack overflow we crash.
1392     assert(THREAD->is_Java_thread(), "only a java thread can be here");
1393     JavaThread* thread = (JavaThread*)THREAD;
1394     bool guard_pages_enabled = thread->stack_guards_enabled();
1395     if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1396     assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1397   }
1398 }
1399 
1400 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1401   HandleMark hm;
1402 
1403   // uncommon_trap() is called at the beginning of the uncommon trap
1404   // handler. Note this fact before we start generating temporary frames
1405   // that can confuse an asynchronous stack walker. This counter is
1406   // decremented at the end of unpack_frames().
1407   thread->inc_in_deopt_handler();
1408 
1409   // We need to update the map if we have biased locking.
1410 #if INCLUDE_JVMCI
1411   // JVMCI might need to get an exception from the stack, which in turn requires the register map to be valid
1412   RegisterMap reg_map(thread, true);
1413 #else
1414   RegisterMap reg_map(thread, UseBiasedLocking);
1415 #endif
1416   frame stub_frame = thread->last_frame();
1417   frame fr = stub_frame.sender(&reg_map);
1418   // Make sure the calling nmethod is not getting deoptimized and removed
1419   // before we are done with it.
1420   nmethodLocker nl(fr.pc());
1421 
1422   // Log a message
1423   Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT " relative=" INTPTR_FORMAT,
1424               trap_request, p2i(fr.pc()), fr.pc() - fr.cb()->code_begin());
1425 
1426   {
1427     ResourceMark rm;
1428 
1429     // Revoke biases of any monitors in the frame to ensure we can migrate them
1430     revoke_biases_of_monitors(thread, fr, &reg_map);
1431 
1432     DeoptReason reason = trap_request_reason(trap_request);
1433     DeoptAction action = trap_request_action(trap_request);
1434 #if INCLUDE_JVMCI
1435     int debug_id = trap_request_debug_id(trap_request);
1436 #endif
1437     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1438 
1439     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
1440     compiledVFrame* cvf = compiledVFrame::cast(vf);
1441 
1442     nmethod* nm = cvf->code();
1443 
1444     ScopeDesc*      trap_scope  = cvf->scope();
1445 
1446     if (TraceDeoptimization) {
1447       ttyLocker ttyl;
1448       tty->print_cr("  bci=%d pc=" INTPTR_FORMAT ", relative_pc=" INTPTR_FORMAT ", method=%s" JVMCI_ONLY(", debug_id=%d"), trap_scope->bci(), p2i(fr.pc()), fr.pc() - nm->code_begin(), trap_scope->method()->name_and_sig_as_C_string()
1449 #if INCLUDE_JVMCI
1450           , debug_id
1451 #endif
1452           );
1453     }
1454 
1455     methodHandle    trap_method = trap_scope->method();
1456     int             trap_bci    = trap_scope->bci();
1457 #if INCLUDE_JVMCI
1458     oop speculation = thread->pending_failed_speculation();
1459     if (nm->is_compiled_by_jvmci()) {
1460       if (speculation != NULL) {
1461         oop speculation_log = nm->speculation_log();
1462         if (speculation_log != NULL) {
1463           if (TraceDeoptimization || TraceUncollectedSpeculations) {
1464             if (SpeculationLog::lastFailed(speculation_log) != NULL) {
1465               tty->print_cr("A speculation that was not collected by the compiler is being overwritten");
1466             }
1467           }
1468           if (TraceDeoptimization) {
1469             tty->print_cr("Saving speculation to speculation log");
1470           }
1471           SpeculationLog::set_lastFailed(speculation_log, speculation);
1472         } else {
1473           if (TraceDeoptimization) {
1474             tty->print_cr("Speculation present but no speculation log");
1475           }
1476         }
1477         thread->set_pending_failed_speculation(NULL);
1478       } else {
1479         if (TraceDeoptimization) {
1480           tty->print_cr("No speculation");
1481         }
1482       }
1483     } else {
1484       assert(speculation == NULL, "There should not be a speculation for method compiled by non-JVMCI compilers");
1485     }
1486 
1487     if (trap_bci == SynchronizationEntryBCI) {
1488       trap_bci = 0;
1489       thread->set_pending_monitorenter(true);
1490     }
1491 
1492     if (reason == Deoptimization::Reason_transfer_to_interpreter) {
1493       thread->set_pending_transfer_to_interpreter(true);
1494     }
1495 #endif
1496 
1497     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
1498 
1499     if (trap_scope->rethrow_exception()) {
1500       if (PrintDeoptimizationDetails) {
1501         tty->print_cr("Exception to be rethrown in the interpreter for method %s::%s at bci %d", trap_method->method_holder()->name()->as_C_string(), trap_method->name()->as_C_string(), trap_bci);
1502       }
1503       GrowableArray<ScopeValue*>* expressions = trap_scope->expressions();
1504       guarantee(expressions != NULL, "must have exception to throw");
1505       ScopeValue* topOfStack = expressions->top();
1506       Handle topOfStackObj = StackValue::create_stack_value(&fr, &reg_map, topOfStack)->get_obj();
1507       THREAD->set_pending_exception(topOfStackObj(), NULL, 0);
1508     }
1509 
1510     // Record this event in the histogram.
1511     gather_statistics(reason, action, trap_bc);
1512 
1513     // Ensure that we can record deopt. history:
1514     // Need MDO to record RTM code generation state.
1515     bool create_if_missing = ProfileTraps || UseCodeAging RTM_OPT_ONLY( || UseRTMLocking );
1516 
1517     methodHandle profiled_method;
1518 #if INCLUDE_JVMCI
1519     if (nm->is_compiled_by_jvmci()) {
1520       profiled_method = nm->method();
1521     } else {
1522       profiled_method = trap_method;
1523     }
1524 #else
1525     profiled_method = trap_method;
1526 #endif
1527 
1528     MethodData* trap_mdo =
1529       get_method_data(thread, profiled_method, create_if_missing);
1530 
1531     // Log a message
1532     Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1533                               trap_reason_name(reason), trap_action_name(action), p2i(fr.pc()),
1534                               trap_method->name_and_sig_as_C_string(), trap_bci);
1535 
1536     // Print a bunch of diagnostics, if requested.
1537     if (TraceDeoptimization || LogCompilation) {
1538       ResourceMark rm;
1539       ttyLocker ttyl;
1540       char buf[100];
1541       if (xtty != NULL) {
1542         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT "' %s",
1543                          os::current_thread_id(),
1544                          format_trap_request(buf, sizeof(buf), trap_request));
1545         nm->log_identity(xtty);
1546       }
1547       Symbol* class_name = NULL;
1548       bool unresolved = false;
1549       if (unloaded_class_index >= 0) {
1550         constantPoolHandle constants (THREAD, trap_method->constants());
1551         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1552           class_name = constants->klass_name_at(unloaded_class_index);
1553           unresolved = true;
1554           if (xtty != NULL)
1555             xtty->print(" unresolved='1'");
1556         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1557           class_name = constants->symbol_at(unloaded_class_index);
1558         }
1559         if (xtty != NULL)
1560           xtty->name(class_name);
1561       }
1562       if (xtty != NULL && trap_mdo != NULL && (int)reason < (int)MethodData::_trap_hist_limit) {
1563         // Dump the relevant MDO state.
1564         // This is the deopt count for the current reason, any previous
1565         // reasons or recompiles seen at this point.
1566         int dcnt = trap_mdo->trap_count(reason);
1567         if (dcnt != 0)
1568           xtty->print(" count='%d'", dcnt);
1569         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1570         int dos = (pdata == NULL)? 0: pdata->trap_state();
1571         if (dos != 0) {
1572           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1573           if (trap_state_is_recompiled(dos)) {
1574             int recnt2 = trap_mdo->overflow_recompile_count();
1575             if (recnt2 != 0)
1576               xtty->print(" recompiles2='%d'", recnt2);
1577           }
1578         }
1579       }
1580       if (xtty != NULL) {
1581         xtty->stamp();
1582         xtty->end_head();
1583       }
1584       if (TraceDeoptimization) {  // make noise on the tty
1585         tty->print("Uncommon trap occurred in");
1586         nm->method()->print_short_name(tty);
1587         tty->print(" compiler=%s compile_id=%d", nm->compiler() == NULL ? "" : nm->compiler()->name(), nm->compile_id());
1588 #if INCLUDE_JVMCI
1589         oop installedCode = nm->jvmci_installed_code();
1590         if (installedCode != NULL) {
1591           oop installedCodeName = NULL;
1592           if (installedCode->is_a(InstalledCode::klass())) {
1593             installedCodeName = InstalledCode::name(installedCode);
1594           }
1595           if (installedCodeName != NULL) {
1596             tty->print(" (JVMCI: installedCodeName=%s) ", java_lang_String::as_utf8_string(installedCodeName));
1597           } else {
1598             tty->print(" (JVMCI: installed code has no name) ");
1599           }
1600         } else if (nm->is_compiled_by_jvmci()) {
1601           tty->print(" (JVMCI: no installed code) ");
1602         }
1603 #endif
1604         tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d" JVMCI_ONLY(" debug_id=%d"),
1605                    p2i(fr.pc()),
1606                    os::current_thread_id(),
1607                    trap_reason_name(reason),
1608                    trap_action_name(action),
1609                    unloaded_class_index
1610 #if INCLUDE_JVMCI
1611                    , debug_id
1612 #endif
1613                    );
1614         if (class_name != NULL) {
1615           tty->print(unresolved ? " unresolved class: " : " symbol: ");
1616           class_name->print_symbol_on(tty);
1617         }
1618         tty->cr();
1619       }
1620       if (xtty != NULL) {
1621         // Log the precise location of the trap.
1622         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1623           xtty->begin_elem("jvms bci='%d'", sd->bci());
1624           xtty->method(sd->method());
1625           xtty->end_elem();
1626           if (sd->is_top())  break;
1627         }
1628         xtty->tail("uncommon_trap");
1629       }
1630     }
1631     // (End diagnostic printout.)
1632 
1633     // Load class if necessary
1634     if (unloaded_class_index >= 0) {
1635       constantPoolHandle constants(THREAD, trap_method->constants());
1636       load_class_by_index(constants, unloaded_class_index);
1637     }
1638 
1639     // Flush the nmethod if necessary and desirable.
1640     //
1641     // We need to avoid situations where we are re-flushing the nmethod
1642     // because of a hot deoptimization site.  Repeated flushes at the same
1643     // point need to be detected by the compiler and avoided.  If the compiler
1644     // cannot avoid them (or has a bug and "refuses" to avoid them), this
1645     // module must take measures to avoid an infinite cycle of recompilation
1646     // and deoptimization.  There are several such measures:
1647     //
1648     //   1. If a recompilation is ordered a second time at some site X
1649     //   and for the same reason R, the action is adjusted to 'reinterpret',
1650     //   to give the interpreter time to exercise the method more thoroughly.
1651     //   If this happens, the method's overflow_recompile_count is incremented.
1652     //
1653     //   2. If the compiler fails to reduce the deoptimization rate, then
1654     //   the method's overflow_recompile_count will begin to exceed the set
1655     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
1656     //   is adjusted to 'make_not_compilable', and the method is abandoned
1657     //   to the interpreter.  This is a performance hit for hot methods,
1658     //   but is better than a disastrous infinite cycle of recompilations.
1659     //   (Actually, only the method containing the site X is abandoned.)
1660     //
1661     //   3. In parallel with the previous measures, if the total number of
1662     //   recompilations of a method exceeds the much larger set limit
1663     //   PerMethodRecompilationCutoff, the method is abandoned.
1664     //   This should only happen if the method is very large and has
1665     //   many "lukewarm" deoptimizations.  The code which enforces this
1666     //   limit is elsewhere (class nmethod, class Method).
1667     //
1668     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1669     // to recompile at each bytecode independently of the per-BCI cutoff.
1670     //
1671     // The decision to update code is up to the compiler, and is encoded
1672     // in the Action_xxx code.  If the compiler requests Action_none
1673     // no trap state is changed, no compiled code is changed, and the
1674     // computation suffers along in the interpreter.
1675     //
1676     // The other action codes specify various tactics for decompilation
1677     // and recompilation.  Action_maybe_recompile is the loosest, and
1678     // allows the compiled code to stay around until enough traps are seen,
1679     // and until the compiler gets around to recompiling the trapping method.
1680     //
1681     // The other actions cause immediate removal of the present code.
1682 
1683     // Traps caused by injected profile shouldn't pollute trap counts.
1684     bool injected_profile_trap = trap_method->has_injected_profile() &&
1685                                  (reason == Reason_intrinsic || reason == Reason_unreached);
1686 
1687     bool update_trap_state = (reason != Reason_tenured) && !injected_profile_trap;
1688     bool make_not_entrant = false;
1689     bool make_not_compilable = false;
1690     bool reprofile = false;
1691     switch (action) {
1692     case Action_none:
1693       // Keep the old code.
1694       update_trap_state = false;
1695       break;
1696     case Action_maybe_recompile:
1697       // Do not need to invalidate the present code, but we can
1698       // initiate another
1699       // Start compiler without (necessarily) invalidating the nmethod.
1700       // The system will tolerate the old code, but new code should be
1701       // generated when possible.
1702       break;
1703     case Action_reinterpret:
1704       // Go back into the interpreter for a while, and then consider
1705       // recompiling form scratch.
1706       make_not_entrant = true;
1707       // Reset invocation counter for outer most method.
1708       // This will allow the interpreter to exercise the bytecodes
1709       // for a while before recompiling.
1710       // By contrast, Action_make_not_entrant is immediate.
1711       //
1712       // Note that the compiler will track null_check, null_assert,
1713       // range_check, and class_check events and log them as if they
1714       // had been traps taken from compiled code.  This will update
1715       // the MDO trap history so that the next compilation will
1716       // properly detect hot trap sites.
1717       reprofile = true;
1718       break;
1719     case Action_make_not_entrant:
1720       // Request immediate recompilation, and get rid of the old code.
1721       // Make them not entrant, so next time they are called they get
1722       // recompiled.  Unloaded classes are loaded now so recompile before next
1723       // time they are called.  Same for uninitialized.  The interpreter will
1724       // link the missing class, if any.
1725       make_not_entrant = true;
1726       break;
1727     case Action_make_not_compilable:
1728       // Give up on compiling this method at all.
1729       make_not_entrant = true;
1730       make_not_compilable = true;
1731       break;
1732     default:
1733       ShouldNotReachHere();
1734     }
1735 
1736     // Setting +ProfileTraps fixes the following, on all platforms:
1737     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
1738     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1739     // recompile relies on a MethodData* to record heroic opt failures.
1740 
1741     // Whether the interpreter is producing MDO data or not, we also need
1742     // to use the MDO to detect hot deoptimization points and control
1743     // aggressive optimization.
1744     bool inc_recompile_count = false;
1745     ProfileData* pdata = NULL;
1746     if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1747       assert(trap_mdo == get_method_data(thread, profiled_method, false), "sanity");
1748       uint this_trap_count = 0;
1749       bool maybe_prior_trap = false;
1750       bool maybe_prior_recompile = false;
1751       pdata = query_update_method_data(trap_mdo, trap_bci, reason, true,
1752 #if INCLUDE_JVMCI
1753                                    nm->is_compiled_by_jvmci() && nm->is_osr_method(),
1754 #endif
1755                                    nm->method(),
1756                                    //outputs:
1757                                    this_trap_count,
1758                                    maybe_prior_trap,
1759                                    maybe_prior_recompile);
1760       // Because the interpreter also counts null, div0, range, and class
1761       // checks, these traps from compiled code are double-counted.
1762       // This is harmless; it just means that the PerXTrapLimit values
1763       // are in effect a little smaller than they look.
1764 
1765       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1766       if (per_bc_reason != Reason_none) {
1767         // Now take action based on the partially known per-BCI history.
1768         if (maybe_prior_trap
1769             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1770           // If there are too many traps at this BCI, force a recompile.
1771           // This will allow the compiler to see the limit overflow, and
1772           // take corrective action, if possible.  The compiler generally
1773           // does not use the exact PerBytecodeTrapLimit value, but instead
1774           // changes its tactics if it sees any traps at all.  This provides
1775           // a little hysteresis, delaying a recompile until a trap happens
1776           // several times.
1777           //
1778           // Actually, since there is only one bit of counter per BCI,
1779           // the possible per-BCI counts are {0,1,(per-method count)}.
1780           // This produces accurate results if in fact there is only
1781           // one hot trap site, but begins to get fuzzy if there are
1782           // many sites.  For example, if there are ten sites each
1783           // trapping two or more times, they each get the blame for
1784           // all of their traps.
1785           make_not_entrant = true;
1786         }
1787 
1788         // Detect repeated recompilation at the same BCI, and enforce a limit.
1789         if (make_not_entrant && maybe_prior_recompile) {
1790           // More than one recompile at this point.
1791           inc_recompile_count = maybe_prior_trap;
1792         }
1793       } else {
1794         // For reasons which are not recorded per-bytecode, we simply
1795         // force recompiles unconditionally.
1796         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1797         make_not_entrant = true;
1798       }
1799 
1800       // Go back to the compiler if there are too many traps in this method.
1801       if (this_trap_count >= per_method_trap_limit(reason)) {
1802         // If there are too many traps in this method, force a recompile.
1803         // This will allow the compiler to see the limit overflow, and
1804         // take corrective action, if possible.
1805         // (This condition is an unlikely backstop only, because the
1806         // PerBytecodeTrapLimit is more likely to take effect first,
1807         // if it is applicable.)
1808         make_not_entrant = true;
1809       }
1810 
1811       // Here's more hysteresis:  If there has been a recompile at
1812       // this trap point already, run the method in the interpreter
1813       // for a while to exercise it more thoroughly.
1814       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1815         reprofile = true;
1816       }
1817     }
1818 
1819     // Take requested actions on the method:
1820 
1821     // Recompile
1822     if (make_not_entrant) {
1823       if (!nm->make_not_entrant()) {
1824         return; // the call did not change nmethod's state
1825       }
1826 
1827       if (pdata != NULL) {
1828         // Record the recompilation event, if any.
1829         int tstate0 = pdata->trap_state();
1830         int tstate1 = trap_state_set_recompiled(tstate0, true);
1831         if (tstate1 != tstate0)
1832           pdata->set_trap_state(tstate1);
1833       }
1834 
1835 #if INCLUDE_RTM_OPT
1836       // Restart collecting RTM locking abort statistic if the method
1837       // is recompiled for a reason other than RTM state change.
1838       // Assume that in new recompiled code the statistic could be different,
1839       // for example, due to different inlining.
1840       if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1841           UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1842         trap_mdo->atomic_set_rtm_state(ProfileRTM);
1843       }
1844 #endif
1845       // For code aging we count traps separately here, using make_not_entrant()
1846       // as a guard against simultaneous deopts in multiple threads.
1847       if (reason == Reason_tenured && trap_mdo != NULL) {
1848         trap_mdo->inc_tenure_traps();
1849       }
1850     }
1851 
1852     if (inc_recompile_count) {
1853       trap_mdo->inc_overflow_recompile_count();
1854       if ((uint)trap_mdo->overflow_recompile_count() >
1855           (uint)PerBytecodeRecompilationCutoff) {
1856         // Give up on the method containing the bad BCI.
1857         if (trap_method() == nm->method()) {
1858           make_not_compilable = true;
1859         } else {
1860           trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1861           // But give grace to the enclosing nm->method().
1862         }
1863       }
1864     }
1865 
1866     // Reprofile
1867     if (reprofile) {
1868       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1869     }
1870 
1871     // Give up compiling
1872     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1873       assert(make_not_entrant, "consistent");
1874       nm->method()->set_not_compilable(CompLevel_full_optimization);
1875     }
1876 
1877   } // Free marked resources
1878 
1879 }
1880 JRT_END
1881 
1882 ProfileData*
1883 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1884                                          int trap_bci,
1885                                          Deoptimization::DeoptReason reason,
1886                                          bool update_total_trap_count,
1887 #if INCLUDE_JVMCI
1888                                          bool is_osr,
1889 #endif
1890                                          Method* compiled_method,
1891                                          //outputs:
1892                                          uint& ret_this_trap_count,
1893                                          bool& ret_maybe_prior_trap,
1894                                          bool& ret_maybe_prior_recompile) {
1895   bool maybe_prior_trap = false;
1896   bool maybe_prior_recompile = false;
1897   uint this_trap_count = 0;
1898   if (update_total_trap_count) {
1899     uint idx = reason;
1900 #if INCLUDE_JVMCI
1901     if (is_osr) {
1902       idx += Reason_LIMIT;
1903     }
1904 #endif
1905     uint prior_trap_count = trap_mdo->trap_count(idx);
1906     this_trap_count  = trap_mdo->inc_trap_count(idx);
1907 
1908     // If the runtime cannot find a place to store trap history,
1909     // it is estimated based on the general condition of the method.
1910     // If the method has ever been recompiled, or has ever incurred
1911     // a trap with the present reason , then this BCI is assumed
1912     // (pessimistically) to be the culprit.
1913     maybe_prior_trap      = (prior_trap_count != 0);
1914     maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1915   }
1916   ProfileData* pdata = NULL;
1917 
1918 
1919   // For reasons which are recorded per bytecode, we check per-BCI data.
1920   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1921   assert(per_bc_reason != Reason_none || update_total_trap_count, "must be");
1922   if (per_bc_reason != Reason_none) {
1923     // Find the profile data for this BCI.  If there isn't one,
1924     // try to allocate one from the MDO's set of spares.
1925     // This will let us detect a repeated trap at this point.
1926     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1927 
1928     if (pdata != NULL) {
1929       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1930         if (LogCompilation && xtty != NULL) {
1931           ttyLocker ttyl;
1932           // no more room for speculative traps in this MDO
1933           xtty->elem("speculative_traps_oom");
1934         }
1935       }
1936       // Query the trap state of this profile datum.
1937       int tstate0 = pdata->trap_state();
1938       if (!trap_state_has_reason(tstate0, per_bc_reason))
1939         maybe_prior_trap = false;
1940       if (!trap_state_is_recompiled(tstate0))
1941         maybe_prior_recompile = false;
1942 
1943       // Update the trap state of this profile datum.
1944       int tstate1 = tstate0;
1945       // Record the reason.
1946       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1947       // Store the updated state on the MDO, for next time.
1948       if (tstate1 != tstate0)
1949         pdata->set_trap_state(tstate1);
1950     } else {
1951       if (LogCompilation && xtty != NULL) {
1952         ttyLocker ttyl;
1953         // Missing MDP?  Leave a small complaint in the log.
1954         xtty->elem("missing_mdp bci='%d'", trap_bci);
1955       }
1956     }
1957   }
1958 
1959   // Return results:
1960   ret_this_trap_count = this_trap_count;
1961   ret_maybe_prior_trap = maybe_prior_trap;
1962   ret_maybe_prior_recompile = maybe_prior_recompile;
1963   return pdata;
1964 }
1965 
1966 void
1967 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1968   ResourceMark rm;
1969   // Ignored outputs:
1970   uint ignore_this_trap_count;
1971   bool ignore_maybe_prior_trap;
1972   bool ignore_maybe_prior_recompile;
1973   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1974   // JVMCI uses the total counts to determine if deoptimizations are happening too frequently -> do not adjust total counts
1975   bool update_total_counts = JVMCI_ONLY(false) NOT_JVMCI(true);
1976   query_update_method_data(trap_mdo, trap_bci,
1977                            (DeoptReason)reason,
1978                            update_total_counts,
1979 #if INCLUDE_JVMCI
1980                            false,
1981 #endif
1982                            NULL,
1983                            ignore_this_trap_count,
1984                            ignore_maybe_prior_trap,
1985                            ignore_maybe_prior_recompile);
1986 }
1987 
1988 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1989   if (TraceDeoptimization) {
1990     tty->print("Uncommon trap ");
1991   }
1992   // Still in Java no safepoints
1993   {
1994     // This enters VM and may safepoint
1995     uncommon_trap_inner(thread, trap_request);
1996   }
1997   return fetch_unroll_info_helper(thread);
1998 }
1999 
2000 // Local derived constants.
2001 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
2002 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
2003 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
2004 
2005 //---------------------------trap_state_reason---------------------------------
2006 Deoptimization::DeoptReason
2007 Deoptimization::trap_state_reason(int trap_state) {
2008   // This assert provides the link between the width of DataLayout::trap_bits
2009   // and the encoding of "recorded" reasons.  It ensures there are enough
2010   // bits to store all needed reasons in the per-BCI MDO profile.
2011   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2012   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2013   trap_state -= recompile_bit;
2014   if (trap_state == DS_REASON_MASK) {
2015     return Reason_many;
2016   } else {
2017     assert((int)Reason_none == 0, "state=0 => Reason_none");
2018     return (DeoptReason)trap_state;
2019   }
2020 }
2021 //-------------------------trap_state_has_reason-------------------------------
2022 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2023   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
2024   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
2025   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2026   trap_state -= recompile_bit;
2027   if (trap_state == DS_REASON_MASK) {
2028     return -1;  // true, unspecifically (bottom of state lattice)
2029   } else if (trap_state == reason) {
2030     return 1;   // true, definitely
2031   } else if (trap_state == 0) {
2032     return 0;   // false, definitely (top of state lattice)
2033   } else {
2034     return 0;   // false, definitely
2035   }
2036 }
2037 //-------------------------trap_state_add_reason-------------------------------
2038 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
2039   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
2040   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
2041   trap_state -= recompile_bit;
2042   if (trap_state == DS_REASON_MASK) {
2043     return trap_state + recompile_bit;     // already at state lattice bottom
2044   } else if (trap_state == reason) {
2045     return trap_state + recompile_bit;     // the condition is already true
2046   } else if (trap_state == 0) {
2047     return reason + recompile_bit;          // no condition has yet been true
2048   } else {
2049     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
2050   }
2051 }
2052 //-----------------------trap_state_is_recompiled------------------------------
2053 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2054   return (trap_state & DS_RECOMPILE_BIT) != 0;
2055 }
2056 //-----------------------trap_state_set_recompiled-----------------------------
2057 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
2058   if (z)  return trap_state |  DS_RECOMPILE_BIT;
2059   else    return trap_state & ~DS_RECOMPILE_BIT;
2060 }
2061 //---------------------------format_trap_state---------------------------------
2062 // This is used for debugging and diagnostics, including LogFile output.
2063 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2064                                               int trap_state) {
2065   DeoptReason reason      = trap_state_reason(trap_state);
2066   bool        recomp_flag = trap_state_is_recompiled(trap_state);
2067   // Re-encode the state from its decoded components.
2068   int decoded_state = 0;
2069   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
2070     decoded_state = trap_state_add_reason(decoded_state, reason);
2071   if (recomp_flag)
2072     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
2073   // If the state re-encodes properly, format it symbolically.
2074   // Because this routine is used for debugging and diagnostics,
2075   // be robust even if the state is a strange value.
2076   size_t len;
2077   if (decoded_state != trap_state) {
2078     // Random buggy state that doesn't decode??
2079     len = jio_snprintf(buf, buflen, "#%d", trap_state);
2080   } else {
2081     len = jio_snprintf(buf, buflen, "%s%s",
2082                        trap_reason_name(reason),
2083                        recomp_flag ? " recompiled" : "");
2084   }
2085   if (len >= buflen)
2086     buf[buflen-1] = '\0';
2087   return buf;
2088 }
2089 
2090 
2091 //--------------------------------statics--------------------------------------
2092 const char* Deoptimization::_trap_reason_name[] = {
2093   // Note:  Keep this in sync. with enum DeoptReason.
2094   "none",
2095   "null_check",
2096   "null_assert" JVMCI_ONLY("_or_unreached0"),
2097   "range_check",
2098   "class_check",
2099   "array_check",
2100   "intrinsic" JVMCI_ONLY("_or_type_checked_inlining"),
2101   "bimorphic" JVMCI_ONLY("_or_optimized_type_check"),
2102   "unloaded",
2103   "uninitialized",
2104   "unreached",
2105   "unhandled",
2106   "constraint",
2107   "div0_check",
2108   "age",
2109   "predicate",
2110   "loop_limit_check",
2111   "speculate_class_check",
2112   "speculate_null_check",
2113   "rtm_state_change",
2114   "unstable_if",
2115   "unstable_fused_if",
2116 #if INCLUDE_JVMCI
2117   "aliasing",
2118   "transfer_to_interpreter",
2119   "not_compiled_exception_handler",
2120   "unresolved",
2121   "jsr_mismatch",
2122 #endif
2123   "tenured"
2124 };
2125 const char* Deoptimization::_trap_action_name[] = {
2126   // Note:  Keep this in sync. with enum DeoptAction.
2127   "none",
2128   "maybe_recompile",
2129   "reinterpret",
2130   "make_not_entrant",
2131   "make_not_compilable"
2132 };
2133 
2134 const char* Deoptimization::trap_reason_name(int reason) {
2135   // Check that every reason has a name
2136   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
2137 
2138   if (reason == Reason_many)  return "many";
2139   if ((uint)reason < Reason_LIMIT)
2140     return _trap_reason_name[reason];
2141   static char buf[20];
2142   sprintf(buf, "reason%d", reason);
2143   return buf;
2144 }
2145 const char* Deoptimization::trap_action_name(int action) {
2146   // Check that every action has a name
2147   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
2148 
2149   if ((uint)action < Action_LIMIT)
2150     return _trap_action_name[action];
2151   static char buf[20];
2152   sprintf(buf, "action%d", action);
2153   return buf;
2154 }
2155 
2156 // This is used for debugging and diagnostics, including LogFile output.
2157 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
2158                                                 int trap_request) {
2159   jint unloaded_class_index = trap_request_index(trap_request);
2160   const char* reason = trap_reason_name(trap_request_reason(trap_request));
2161   const char* action = trap_action_name(trap_request_action(trap_request));
2162 #if INCLUDE_JVMCI
2163   int debug_id = trap_request_debug_id(trap_request);
2164 #endif
2165   size_t len;
2166   if (unloaded_class_index < 0) {
2167     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'" JVMCI_ONLY(" debug_id='%d'"),
2168                        reason, action
2169 #if INCLUDE_JVMCI
2170                        ,debug_id
2171 #endif
2172                        );
2173   } else {
2174     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'" JVMCI_ONLY(" debug_id='%d'"),
2175                        reason, action, unloaded_class_index
2176 #if INCLUDE_JVMCI
2177                        ,debug_id
2178 #endif
2179                        );
2180   }
2181   if (len >= buflen)
2182     buf[buflen-1] = '\0';
2183   return buf;
2184 }
2185 
2186 juint Deoptimization::_deoptimization_hist
2187         [Deoptimization::Reason_LIMIT]
2188     [1 + Deoptimization::Action_LIMIT]
2189         [Deoptimization::BC_CASE_LIMIT]
2190   = {0};
2191 
2192 enum {
2193   LSB_BITS = 8,
2194   LSB_MASK = right_n_bits(LSB_BITS)
2195 };
2196 
2197 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2198                                        Bytecodes::Code bc) {
2199   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2200   assert(action >= 0 && action < Action_LIMIT, "oob");
2201   _deoptimization_hist[Reason_none][0][0] += 1;  // total
2202   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
2203   juint* cases = _deoptimization_hist[reason][1+action];
2204   juint* bc_counter_addr = NULL;
2205   juint  bc_counter      = 0;
2206   // Look for an unused counter, or an exact match to this BC.
2207   if (bc != Bytecodes::_illegal) {
2208     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2209       juint* counter_addr = &cases[bc_case];
2210       juint  counter = *counter_addr;
2211       if ((counter == 0 && bc_counter_addr == NULL)
2212           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
2213         // this counter is either free or is already devoted to this BC
2214         bc_counter_addr = counter_addr;
2215         bc_counter = counter | bc;
2216       }
2217     }
2218   }
2219   if (bc_counter_addr == NULL) {
2220     // Overflow, or no given bytecode.
2221     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
2222     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
2223   }
2224   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
2225 }
2226 
2227 jint Deoptimization::total_deoptimization_count() {
2228   return _deoptimization_hist[Reason_none][0][0];
2229 }
2230 
2231 jint Deoptimization::deoptimization_count(DeoptReason reason) {
2232   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
2233   return _deoptimization_hist[reason][0][0];
2234 }
2235 
2236 void Deoptimization::print_statistics() {
2237   juint total = total_deoptimization_count();
2238   juint account = total;
2239   if (total != 0) {
2240     ttyLocker ttyl;
2241     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
2242     tty->print_cr("Deoptimization traps recorded:");
2243     #define PRINT_STAT_LINE(name, r) \
2244       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
2245     PRINT_STAT_LINE("total", total);
2246     // For each non-zero entry in the histogram, print the reason,
2247     // the action, and (if specifically known) the type of bytecode.
2248     for (int reason = 0; reason < Reason_LIMIT; reason++) {
2249       for (int action = 0; action < Action_LIMIT; action++) {
2250         juint* cases = _deoptimization_hist[reason][1+action];
2251         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
2252           juint counter = cases[bc_case];
2253           if (counter != 0) {
2254             char name[1*K];
2255             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
2256             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
2257               bc = Bytecodes::_illegal;
2258             sprintf(name, "%s/%s/%s",
2259                     trap_reason_name(reason),
2260                     trap_action_name(action),
2261                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
2262             juint r = counter >> LSB_BITS;
2263             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
2264             account -= r;
2265           }
2266         }
2267       }
2268     }
2269     if (account != 0) {
2270       PRINT_STAT_LINE("unaccounted", account);
2271     }
2272     #undef PRINT_STAT_LINE
2273     if (xtty != NULL)  xtty->tail("statistics");
2274   }
2275 }
2276 #else // COMPILER2 || SHARK || INCLUDE_JVMCI
2277 
2278 
2279 // Stubs for C1 only system.
2280 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
2281   return false;
2282 }
2283 
2284 const char* Deoptimization::trap_reason_name(int reason) {
2285   return "unknown";
2286 }
2287 
2288 void Deoptimization::print_statistics() {
2289   // no output
2290 }
2291 
2292 void
2293 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
2294   // no udpate
2295 }
2296 
2297 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
2298   return 0;
2299 }
2300 
2301 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
2302                                        Bytecodes::Code bc) {
2303   // no update
2304 }
2305 
2306 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
2307                                               int trap_state) {
2308   jio_snprintf(buf, buflen, "#%d", trap_state);
2309   return buf;
2310 }
2311 
2312 #endif // COMPILER2 || SHARK || INCLUDE_JVMCI