1 /*
   2  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  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 "prims/jvmtiThreadState.hpp"
  41 #include "runtime/biasedLocking.hpp"
  42 #include "runtime/compilationPolicy.hpp"
  43 #include "runtime/deoptimization.hpp"
  44 #include "runtime/interfaceSupport.hpp"
  45 #include "runtime/sharedRuntime.hpp"
  46 #include "runtime/signature.hpp"
  47 #include "runtime/stubRoutines.hpp"
  48 #include "runtime/thread.hpp"
  49 #include "runtime/vframe.hpp"
  50 #include "runtime/vframeArray.hpp"
  51 #include "runtime/vframe_hp.hpp"
  52 #include "utilities/events.hpp"
  53 #include "utilities/xmlstream.hpp"
  54 
  55 PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
  56 
  57 bool DeoptimizationMarker::_is_active = false;
  58 
  59 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
  60                                          int  caller_adjustment,
  61                                          int  caller_actual_parameters,
  62                                          int  number_of_frames,
  63                                          intptr_t* frame_sizes,
  64                                          address* frame_pcs,
  65                                          BasicType return_type) {
  66   _size_of_deoptimized_frame = size_of_deoptimized_frame;
  67   _caller_adjustment         = caller_adjustment;
  68   _caller_actual_parameters  = caller_actual_parameters;
  69   _number_of_frames          = number_of_frames;
  70   _frame_sizes               = frame_sizes;
  71   _frame_pcs                 = frame_pcs;
  72   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
  73   _return_type               = return_type;
  74   _initial_info              = 0;
  75   // PD (x86 only)
  76   _counter_temp              = 0;
  77   _unpack_kind               = 0;
  78   _sender_sp_temp            = 0;
  79 
  80   _total_frame_sizes         = size_of_frames();
  81 }
  82 
  83 
  84 Deoptimization::UnrollBlock::~UnrollBlock() {
  85   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
  86   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
  87   FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
  88 }
  89 
  90 
  91 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
  92   assert(register_number < RegisterMap::reg_count, "checking register number");
  93   return &_register_block[register_number * 2];
  94 }
  95 
  96 
  97 
  98 int Deoptimization::UnrollBlock::size_of_frames() const {
  99   // Acount first for the adjustment of the initial frame
 100   int result = _caller_adjustment;
 101   for (int index = 0; index < number_of_frames(); index++) {
 102     result += frame_sizes()[index];
 103   }
 104   return result;
 105 }
 106 
 107 
 108 void Deoptimization::UnrollBlock::print() {
 109   ttyLocker ttyl;
 110   tty->print_cr("UnrollBlock");
 111   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 112   tty->print(   "  frame_sizes: ");
 113   for (int index = 0; index < number_of_frames(); index++) {
 114     tty->print("%d ", frame_sizes()[index]);
 115   }
 116   tty->cr();
 117 }
 118 
 119 
 120 // In order to make fetch_unroll_info work properly with escape
 121 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
 122 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
 123 // of previously eliminated objects occurs in realloc_objects, which is
 124 // called from the method fetch_unroll_info_helper below.
 125 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
 126   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 127   // but makes the entry a little slower. There is however a little dance we have to
 128   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 129 
 130   // fetch_unroll_info() is called at the beginning of the deoptimization
 131   // handler. Note this fact before we start generating temporary frames
 132   // that can confuse an asynchronous stack walker. This counter is
 133   // decremented at the end of unpack_frames().
 134   thread->inc_in_deopt_handler();
 135 
 136   return fetch_unroll_info_helper(thread);
 137 JRT_END
 138 
 139 
 140 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 141 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
 142 
 143   // Note: there is a safepoint safety issue here. No matter whether we enter
 144   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 145   // the vframeArray is created.
 146   //
 147 
 148   // Allocate our special deoptimization ResourceMark
 149   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
 150   assert(thread->deopt_mark() == NULL, "Pending deopt!");
 151   thread->set_deopt_mark(dmark);
 152 
 153   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
 154   RegisterMap map(thread, true);
 155   RegisterMap dummy_map(thread, false);
 156   // Now get the deoptee with a valid map
 157   frame deoptee = stub_frame.sender(&map);
 158   // Set the deoptee nmethod
 159   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
 160   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
 161 
 162   if (VerifyStack) {
 163     thread->validate_frame_layout();
 164   }
 165 
 166   // Create a growable array of VFrames where each VFrame represents an inlined
 167   // Java frame.  This storage is allocated with the usual system arena.
 168   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 169   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 170   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
 171   while (!vf->is_top()) {
 172     assert(vf->is_compiled_frame(), "Wrong frame type");
 173     chunk->push(compiledVFrame::cast(vf));
 174     vf = vf->sender();
 175   }
 176   assert(vf->is_compiled_frame(), "Wrong frame type");
 177   chunk->push(compiledVFrame::cast(vf));
 178 
 179 #ifdef COMPILER2
 180   // Reallocate the non-escaping objects and restore their fields. Then
 181   // relock objects if synchronization on them was eliminated.
 182   if (DoEscapeAnalysis || EliminateNestedLocks) {
 183     if (EliminateAllocations) {
 184       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 185       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 186 
 187       // The flag return_oop() indicates call sites which return oop
 188       // in compiled code. Such sites include java method calls,
 189       // runtime calls (for example, used to allocate new objects/arrays
 190       // on slow code path) and any other calls generated in compiled code.
 191       // It is not guaranteed that we can get such information here only
 192       // by analyzing bytecode in deoptimized frames. This is why this flag
 193       // is set during method compilation (see Compile::Process_OopMap_Node()).
 194       bool save_oop_result = chunk->at(0)->scope()->return_oop();
 195       Handle return_value;
 196       if (save_oop_result) {
 197         // Reallocation may trigger GC. If deoptimization happened on return from
 198         // call which returns oop we need to save it since it is not in oopmap.
 199         oop result = deoptee.saved_oop_result(&map);
 200         assert(result == NULL || result->is_oop(), "must be oop");
 201         return_value = Handle(thread, result);
 202         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 203         if (TraceDeoptimization) {
 204           ttyLocker ttyl;
 205           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, (void *)result, thread);
 206         }
 207       }
 208       bool reallocated = false;
 209       if (objects != NULL) {
 210         JRT_BLOCK
 211           reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
 212         JRT_END
 213       }
 214       if (reallocated) {
 215         reassign_fields(&deoptee, &map, objects);
 216 #ifndef PRODUCT
 217         if (TraceDeoptimization) {
 218           ttyLocker ttyl;
 219           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
 220           print_objects(objects);
 221         }
 222 #endif
 223       }
 224       if (save_oop_result) {
 225         // Restore result.
 226         deoptee.set_saved_oop_result(&map, return_value());
 227       }
 228     }
 229     if (EliminateLocks) {
 230 #ifndef PRODUCT
 231       bool first = true;
 232 #endif
 233       for (int i = 0; i < chunk->length(); i++) {
 234         compiledVFrame* cvf = chunk->at(i);
 235         assert (cvf->scope() != NULL,"expect only compiled java frames");
 236         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 237         if (monitors->is_nonempty()) {
 238           relock_objects(monitors, thread);
 239 #ifndef PRODUCT
 240           if (TraceDeoptimization) {
 241             ttyLocker ttyl;
 242             for (int j = 0; j < monitors->length(); j++) {
 243               MonitorInfo* mi = monitors->at(j);
 244               if (mi->eliminated()) {
 245                 if (first) {
 246                   first = false;
 247                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
 248                 }
 249                 tty->print_cr("     object <" INTPTR_FORMAT "> locked", (void *)mi->owner());
 250               }
 251             }
 252           }
 253 #endif
 254         }
 255       }
 256     }
 257   }
 258 #endif // COMPILER2
 259   // Ensure that no safepoint is taken after pointers have been stored
 260   // in fields of rematerialized objects.  If a safepoint occurs from here on
 261   // out the java state residing in the vframeArray will be missed.
 262   No_Safepoint_Verifier no_safepoint;
 263 
 264   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
 265 
 266   assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
 267   thread->set_vframe_array_head(array);
 268 
 269   // Now that the vframeArray has been created if we have any deferred local writes
 270   // added by jvmti then we can free up that structure as the data is now in the
 271   // vframeArray
 272 
 273   if (thread->deferred_locals() != NULL) {
 274     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
 275     int i = 0;
 276     do {
 277       // Because of inlining we could have multiple vframes for a single frame
 278       // and several of the vframes could have deferred writes. Find them all.
 279       if (list->at(i)->id() == array->original().id()) {
 280         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
 281         list->remove_at(i);
 282         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
 283         delete dlv;
 284       } else {
 285         i++;
 286       }
 287     } while ( i < list->length() );
 288     if (list->length() == 0) {
 289       thread->set_deferred_locals(NULL);
 290       // free the list and elements back to C heap.
 291       delete list;
 292     }
 293 
 294   }
 295 
 296 #ifndef SHARK
 297   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 298   CodeBlob* cb = stub_frame.cb();
 299   // Verify we have the right vframeArray
 300   assert(cb->frame_size() >= 0, "Unexpected frame size");
 301   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 302 
 303   // If the deopt call site is a MethodHandle invoke call site we have
 304   // to adjust the unpack_sp.
 305   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 306   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 307     unpack_sp = deoptee.unextended_sp();
 308 
 309 #ifdef ASSERT
 310   assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
 311 #endif
 312 #else
 313   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
 314 #endif // !SHARK
 315 
 316   // This is a guarantee instead of an assert because if vframe doesn't match
 317   // we will unpack the wrong deoptimized frame and wind up in strange places
 318   // where it will be very difficult to figure out what went wrong. Better
 319   // to die an early death here than some very obscure death later when the
 320   // trail is cold.
 321   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 322   // in that it will fail to detect a problem when there is one. This needs
 323   // more work in tiger timeframe.
 324   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 325 
 326   int number_of_frames = array->frames();
 327 
 328   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 329   // virtual activation, which is the reverse of the elements in the vframes array.
 330   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 331   // +1 because we always have an interpreter return address for the final slot.
 332   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 333   int popframe_extra_args = 0;
 334   // Create an interpreter return address for the stub to use as its return
 335   // address so the skeletal frames are perfectly walkable
 336   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 337 
 338   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 339   // activation be put back on the expression stack of the caller for reexecution
 340   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
 341     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
 342   }
 343 
 344   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 345   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 346   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 347   //
 348   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 349   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 350 
 351   // It's possible that the number of parameters at the call site is
 352   // different than number of arguments in the callee when method
 353   // handles are used.  If the caller is interpreted get the real
 354   // value so that the proper amount of space can be added to it's
 355   // frame.
 356   bool caller_was_method_handle = false;
 357   if (deopt_sender.is_interpreted_frame()) {
 358     methodHandle method = deopt_sender.interpreter_frame_method();
 359     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 360     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 361       // Method handle invokes may involve fairly arbitrary chains of
 362       // calls so it's impossible to know how much actual space the
 363       // caller has for locals.
 364       caller_was_method_handle = true;
 365     }
 366   }
 367 
 368   //
 369   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 370   // frame_sizes/frame_pcs[1] next oldest frame (int)
 371   // frame_sizes/frame_pcs[n] youngest frame (int)
 372   //
 373   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 374   // owns the space for the return address to it's caller).  Confusing ain't it.
 375   //
 376   // The vframe array can address vframes with indices running from
 377   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 378   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 379   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 380   // so things look a little strange in this loop.
 381   //
 382   int callee_parameters = 0;
 383   int callee_locals = 0;
 384   for (int index = 0; index < array->frames(); index++ ) {
 385     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 386     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 387     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 388     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 389                                                                                                     callee_locals,
 390                                                                                                     index == 0,
 391                                                                                                     popframe_extra_args);
 392     // This pc doesn't have to be perfect just good enough to identify the frame
 393     // as interpreted so the skeleton frame will be walkable
 394     // The correct pc will be set when the skeleton frame is completely filled out
 395     // The final pc we store in the loop is wrong and will be overwritten below
 396     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 397 
 398     callee_parameters = array->element(index)->method()->size_of_parameters();
 399     callee_locals = array->element(index)->method()->max_locals();
 400     popframe_extra_args = 0;
 401   }
 402 
 403   // Compute whether the root vframe returns a float or double value.
 404   BasicType return_type;
 405   {
 406     HandleMark hm;
 407     methodHandle method(thread, array->element(0)->method());
 408     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 409     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 410   }
 411 
 412   // Compute information for handling adapters and adjusting the frame size of the caller.
 413   int caller_adjustment = 0;
 414 
 415   // Compute the amount the oldest interpreter frame will have to adjust
 416   // its caller's stack by. If the caller is a compiled frame then
 417   // we pretend that the callee has no parameters so that the
 418   // extension counts for the full amount of locals and not just
 419   // locals-parms. This is because without a c2i adapter the parm
 420   // area as created by the compiled frame will not be usable by
 421   // the interpreter. (Depending on the calling convention there
 422   // may not even be enough space).
 423 
 424   // QQQ I'd rather see this pushed down into last_frame_adjust
 425   // and have it take the sender (aka caller).
 426 
 427   if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
 428     caller_adjustment = last_frame_adjust(0, callee_locals);
 429   } else if (callee_locals > callee_parameters) {
 430     // The caller frame may need extending to accommodate
 431     // non-parameter locals of the first unpacked interpreted frame.
 432     // Compute that adjustment.
 433     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 434   }
 435 
 436   // If the sender is deoptimized the we must retrieve the address of the handler
 437   // since the frame will "magically" show the original pc before the deopt
 438   // and we'd undo the deopt.
 439 
 440   frame_pcs[0] = deopt_sender.raw_pc();
 441 
 442 #ifndef SHARK
 443   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 444 #endif // SHARK
 445 
 446   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 447                                       caller_adjustment * BytesPerWord,
 448                                       caller_was_method_handle ? 0 : callee_parameters,
 449                                       number_of_frames,
 450                                       frame_sizes,
 451                                       frame_pcs,
 452                                       return_type);
 453   // On some platforms, we need a way to pass some platform dependent
 454   // information to the unpacking code so the skeletal frames come out
 455   // correct (initial fp value, unextended sp, ...)
 456   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 457 
 458   if (array->frames() > 1) {
 459     if (VerifyStack && TraceDeoptimization) {
 460       ttyLocker ttyl;
 461       tty->print_cr("Deoptimizing method containing inlining");
 462     }
 463   }
 464 
 465   array->set_unroll_block(info);
 466   return info;
 467 }
 468 
 469 // Called to cleanup deoptimization data structures in normal case
 470 // after unpacking to stack and when stack overflow error occurs
 471 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 472                                         vframeArray *array) {
 473 
 474   // Get array if coming from exception
 475   if (array == NULL) {
 476     array = thread->vframe_array_head();
 477   }
 478   thread->set_vframe_array_head(NULL);
 479 
 480   // Free the previous UnrollBlock
 481   vframeArray* old_array = thread->vframe_array_last();
 482   thread->set_vframe_array_last(array);
 483 
 484   if (old_array != NULL) {
 485     UnrollBlock* old_info = old_array->unroll_block();
 486     old_array->set_unroll_block(NULL);
 487     delete old_info;
 488     delete old_array;
 489   }
 490 
 491   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 492   // inside the vframeArray (StackValueCollections)
 493 
 494   delete thread->deopt_mark();
 495   thread->set_deopt_mark(NULL);
 496   thread->set_deopt_nmethod(NULL);
 497 
 498 
 499   if (JvmtiExport::can_pop_frame()) {
 500 #ifndef CC_INTERP
 501     // Regardless of whether we entered this routine with the pending
 502     // popframe condition bit set, we should always clear it now
 503     thread->clear_popframe_condition();
 504 #else
 505     // C++ interpreter will clear has_pending_popframe when it enters
 506     // with method_resume. For deopt_resume2 we clear it now.
 507     if (thread->popframe_forcing_deopt_reexecution())
 508         thread->clear_popframe_condition();
 509 #endif /* CC_INTERP */
 510   }
 511 
 512   // unpack_frames() is called at the end of the deoptimization handler
 513   // and (in C2) at the end of the uncommon trap handler. Note this fact
 514   // so that an asynchronous stack walker can work again. This counter is
 515   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 516   // the beginning of uncommon_trap().
 517   thread->dec_in_deopt_handler();
 518 }
 519 
 520 
 521 // Return BasicType of value being returned
 522 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 523 
 524   // We are already active int he special DeoptResourceMark any ResourceObj's we
 525   // allocate will be freed at the end of the routine.
 526 
 527   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 528   // but makes the entry a little slower. There is however a little dance we have to
 529   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 530   ResetNoHandleMark rnhm; // No-op in release/product versions
 531   HandleMark hm;
 532 
 533   frame stub_frame = thread->last_frame();
 534 
 535   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 536   // must point to the vframeArray for the unpack frame.
 537   vframeArray* array = thread->vframe_array_head();
 538 
 539 #ifndef PRODUCT
 540   if (TraceDeoptimization) {
 541     ttyLocker ttyl;
 542     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
 543   }
 544 #endif
 545   Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
 546               stub_frame.pc(), stub_frame.sp(), exec_mode);
 547 
 548   UnrollBlock* info = array->unroll_block();
 549 
 550   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 551   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 552 
 553   BasicType bt = info->return_type();
 554 
 555   // If we have an exception pending, claim that the return type is an oop
 556   // so the deopt_blob does not overwrite the exception_oop.
 557 
 558   if (exec_mode == Unpack_exception)
 559     bt = T_OBJECT;
 560 
 561   // Cleanup thread deopt data
 562   cleanup_deopt_info(thread, array);
 563 
 564 #ifndef PRODUCT
 565   if (VerifyStack) {
 566     ResourceMark res_mark;
 567 
 568     thread->validate_frame_layout();
 569 
 570     // Verify that the just-unpacked frames match the interpreter's
 571     // notions of expression stack and locals
 572     vframeArray* cur_array = thread->vframe_array_last();
 573     RegisterMap rm(thread, false);
 574     rm.set_include_argument_oops(false);
 575     bool is_top_frame = true;
 576     int callee_size_of_parameters = 0;
 577     int callee_max_locals = 0;
 578     for (int i = 0; i < cur_array->frames(); i++) {
 579       vframeArrayElement* el = cur_array->element(i);
 580       frame* iframe = el->iframe();
 581       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 582 
 583       // Get the oop map for this bci
 584       InterpreterOopMap mask;
 585       int cur_invoke_parameter_size = 0;
 586       bool try_next_mask = false;
 587       int next_mask_expression_stack_size = -1;
 588       int top_frame_expression_stack_adjustment = 0;
 589       methodHandle mh(thread, iframe->interpreter_frame_method());
 590       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 591       BytecodeStream str(mh);
 592       str.set_start(iframe->interpreter_frame_bci());
 593       int max_bci = mh->code_size();
 594       // Get to the next bytecode if possible
 595       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 596       // Check to see if we can grab the number of outgoing arguments
 597       // at an uncommon trap for an invoke (where the compiler
 598       // generates debug info before the invoke has executed)
 599       Bytecodes::Code cur_code = str.next();
 600       if (cur_code == Bytecodes::_invokevirtual   ||
 601           cur_code == Bytecodes::_invokespecial   ||
 602           cur_code == Bytecodes::_invokestatic    ||
 603           cur_code == Bytecodes::_invokeinterface ||
 604           cur_code == Bytecodes::_invokedynamic) {
 605         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 606         Symbol* signature = invoke.signature();
 607         ArgumentSizeComputer asc(signature);
 608         cur_invoke_parameter_size = asc.size();
 609         if (invoke.has_receiver()) {
 610           // Add in receiver
 611           ++cur_invoke_parameter_size;
 612         }
 613         if (i != 0 && !invoke.is_invokedynamic() && MethodHandles::has_member_arg(invoke.klass(), invoke.name())) {
 614           callee_size_of_parameters++;
 615         }
 616       }
 617       if (str.bci() < max_bci) {
 618         Bytecodes::Code bc = str.next();
 619         if (bc >= 0) {
 620           // The interpreter oop map generator reports results before
 621           // the current bytecode has executed except in the case of
 622           // calls. It seems to be hard to tell whether the compiler
 623           // has emitted debug information matching the "state before"
 624           // a given bytecode or the state after, so we try both
 625           switch (cur_code) {
 626             case Bytecodes::_invokevirtual:
 627             case Bytecodes::_invokespecial:
 628             case Bytecodes::_invokestatic:
 629             case Bytecodes::_invokeinterface:
 630             case Bytecodes::_invokedynamic:
 631             case Bytecodes::_athrow:
 632               break;
 633             default: {
 634               InterpreterOopMap next_mask;
 635               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 636               next_mask_expression_stack_size = next_mask.expression_stack_size();
 637               // Need to subtract off the size of the result type of
 638               // the bytecode because this is not described in the
 639               // debug info but returned to the interpreter in the TOS
 640               // caching register
 641               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 642               if (bytecode_result_type != T_ILLEGAL) {
 643                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 644               }
 645               assert(top_frame_expression_stack_adjustment >= 0, "");
 646               try_next_mask = true;
 647               break;
 648             }
 649           }
 650         }
 651       }
 652 
 653       // Verify stack depth and oops in frame
 654       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 655       if (!(
 656             /* SPARC */
 657             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 658             /* x86 */
 659             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 660             (try_next_mask &&
 661              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 662                                                                     top_frame_expression_stack_adjustment))) ||
 663             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 664             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute || el->should_reexecute()) &&
 665              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 666             )) {
 667         ttyLocker ttyl;
 668 
 669         // Print out some information that will help us debug the problem
 670         tty->print_cr("Wrong number of expression stack elements during deoptimization");
 671         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 672         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 673                       iframe->interpreter_frame_expression_stack_size());
 674         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 675         tty->print_cr("  try_next_mask = %d", try_next_mask);
 676         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 677         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 678         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 679         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 680         tty->print_cr("  exec_mode = %d", exec_mode);
 681         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 682         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
 683         tty->print_cr("  Interpreted frames:");
 684         for (int k = 0; k < cur_array->frames(); k++) {
 685           vframeArrayElement* el = cur_array->element(k);
 686           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 687         }
 688         cur_array->print_on_2(tty);
 689         guarantee(false, "wrong number of expression stack elements during deopt");
 690       }
 691       VerifyOopClosure verify;
 692       iframe->oops_interpreted_do(&verify, NULL, &rm, false);
 693       callee_size_of_parameters = mh->size_of_parameters();
 694       callee_max_locals = mh->max_locals();
 695       is_top_frame = false;
 696     }
 697   }
 698 #endif /* !PRODUCT */
 699 
 700 
 701   return bt;
 702 JRT_END
 703 
 704 
 705 int Deoptimization::deoptimize_dependents() {
 706   Threads::deoptimized_wrt_marked_nmethods();
 707   return 0;
 708 }
 709 
 710 Deoptimization::DeoptAction Deoptimization::_unloaded_action
 711   = Deoptimization::Action_reinterpret;
 712 
 713 #ifdef COMPILER2
 714 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
 715   Handle pending_exception(thread->pending_exception());
 716   const char* exception_file = thread->exception_file();
 717   int exception_line = thread->exception_line();
 718   thread->clear_pending_exception();
 719 
 720   for (int i = 0; i < objects->length(); i++) {
 721     assert(objects->at(i)->is_object(), "invalid debug information");
 722     ObjectValue* sv = (ObjectValue*) objects->at(i);
 723 
 724     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 725     oop obj = NULL;
 726 
 727     if (k->oop_is_instance()) {
 728       InstanceKlass* ik = InstanceKlass::cast(k());
 729       obj = ik->allocate_instance(CHECK_(false));
 730     } else if (k->oop_is_typeArray()) {
 731       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 732       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
 733       int len = sv->field_size() / type2size[ak->element_type()];
 734       obj = ak->allocate(len, CHECK_(false));
 735     } else if (k->oop_is_objArray()) {
 736       ObjArrayKlass* ak = ObjArrayKlass::cast(k());
 737       obj = ak->allocate(sv->field_size(), CHECK_(false));
 738     }
 739 
 740     assert(obj != NULL, "allocation failed");
 741     assert(sv->value().is_null(), "redundant reallocation");
 742     sv->set_value(obj);
 743   }
 744 
 745   if (pending_exception.not_null()) {
 746     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
 747   }
 748 
 749   return true;
 750 }
 751 
 752 // This assumes that the fields are stored in ObjectValue in the same order
 753 // they are yielded by do_nonstatic_fields.
 754 class FieldReassigner: public FieldClosure {
 755   frame* _fr;
 756   RegisterMap* _reg_map;
 757   ObjectValue* _sv;
 758   InstanceKlass* _ik;
 759   oop _obj;
 760 
 761   int _i;
 762 public:
 763   FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
 764     _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
 765 
 766   int i() const { return _i; }
 767 
 768 
 769   void do_field(fieldDescriptor* fd) {
 770     intptr_t val;
 771     StackValue* value =
 772       StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
 773     int offset = fd->offset();
 774     switch (fd->field_type()) {
 775     case T_OBJECT: case T_ARRAY:
 776       assert(value->type() == T_OBJECT, "Agreement.");
 777       _obj->obj_field_put(offset, value->get_obj()());
 778       break;
 779 
 780     case T_LONG: case T_DOUBLE: {
 781       assert(value->type() == T_INT, "Agreement.");
 782       StackValue* low =
 783         StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
 784 #ifdef _LP64
 785       jlong res = (jlong)low->get_int();
 786 #else
 787 #ifdef SPARC
 788       // For SPARC we have to swap high and low words.
 789       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 790 #else
 791       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 792 #endif //SPARC
 793 #endif
 794       _obj->long_field_put(offset, res);
 795       break;
 796     }
 797     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 798     case T_INT: case T_FLOAT: // 4 bytes.
 799       assert(value->type() == T_INT, "Agreement.");
 800       val = value->get_int();
 801       _obj->int_field_put(offset, (jint)*((jint*)&val));
 802       break;
 803 
 804     case T_SHORT: case T_CHAR: // 2 bytes
 805       assert(value->type() == T_INT, "Agreement.");
 806       val = value->get_int();
 807       _obj->short_field_put(offset, (jshort)*((jint*)&val));
 808       break;
 809 
 810     case T_BOOLEAN: case T_BYTE: // 1 byte
 811       assert(value->type() == T_INT, "Agreement.");
 812       val = value->get_int();
 813       _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
 814       break;
 815 
 816     default:
 817       ShouldNotReachHere();
 818     }
 819     _i++;
 820   }
 821 };
 822 
 823 // restore elements of an eliminated type array
 824 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
 825   int index = 0;
 826   intptr_t val;
 827 
 828   for (int i = 0; i < sv->field_size(); i++) {
 829     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 830     switch(type) {
 831     case T_LONG: case T_DOUBLE: {
 832       assert(value->type() == T_INT, "Agreement.");
 833       StackValue* low =
 834         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 835 #ifdef _LP64
 836       jlong res = (jlong)low->get_int();
 837 #else
 838 #ifdef SPARC
 839       // For SPARC we have to swap high and low words.
 840       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 841 #else
 842       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 843 #endif //SPARC
 844 #endif
 845       obj->long_at_put(index, res);
 846       break;
 847     }
 848 
 849     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 850     case T_INT: case T_FLOAT: // 4 bytes.
 851       assert(value->type() == T_INT, "Agreement.");
 852       val = value->get_int();
 853       obj->int_at_put(index, (jint)*((jint*)&val));
 854       break;
 855 
 856     case T_SHORT: case T_CHAR: // 2 bytes
 857       assert(value->type() == T_INT, "Agreement.");
 858       val = value->get_int();
 859       obj->short_at_put(index, (jshort)*((jint*)&val));
 860       break;
 861 
 862     case T_BOOLEAN: case T_BYTE: // 1 byte
 863       assert(value->type() == T_INT, "Agreement.");
 864       val = value->get_int();
 865       obj->bool_at_put(index, (jboolean)*((jint*)&val));
 866       break;
 867 
 868       default:
 869         ShouldNotReachHere();
 870     }
 871     index++;
 872   }
 873 }
 874 
 875 
 876 // restore fields of an eliminated object array
 877 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
 878   for (int i = 0; i < sv->field_size(); i++) {
 879     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 880     assert(value->type() == T_OBJECT, "object element expected");
 881     obj->obj_at_put(i, value->get_obj()());
 882   }
 883 }
 884 
 885 
 886 // restore fields of all eliminated objects and arrays
 887 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
 888   for (int i = 0; i < objects->length(); i++) {
 889     ObjectValue* sv = (ObjectValue*) objects->at(i);
 890     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 891     Handle obj = sv->value();
 892     assert(obj.not_null(), "reallocation was missed");
 893 
 894     if (k->oop_is_instance()) {
 895       InstanceKlass* ik = InstanceKlass::cast(k());
 896       FieldReassigner reassign(fr, reg_map, sv, obj());
 897       ik->do_nonstatic_fields(&reassign);
 898     } else if (k->oop_is_typeArray()) {
 899       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 900       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
 901     } else if (k->oop_is_objArray()) {
 902       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
 903     }
 904   }
 905 }
 906 
 907 
 908 // relock objects for which synchronization was eliminated
 909 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
 910   for (int i = 0; i < monitors->length(); i++) {
 911     MonitorInfo* mon_info = monitors->at(i);
 912     if (mon_info->eliminated()) {
 913       assert(mon_info->owner() != NULL, "reallocation was missed");
 914       Handle obj = Handle(mon_info->owner());
 915       markOop mark = obj->mark();
 916       if (UseBiasedLocking && mark->has_bias_pattern()) {
 917         // New allocated objects may have the mark set to anonymously biased.
 918         // Also the deoptimized method may called methods with synchronization
 919         // where the thread-local object is bias locked to the current thread.
 920         assert(mark->is_biased_anonymously() ||
 921                mark->biased_locker() == thread, "should be locked to current thread");
 922         // Reset mark word to unbiased prototype.
 923         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
 924         obj->set_mark(unbiased_prototype);
 925       }
 926       BasicLock* lock = mon_info->lock();
 927       ObjectSynchronizer::slow_enter(obj, lock, thread);
 928     }
 929     assert(mon_info->owner()->is_locked(), "object must be locked now");
 930   }
 931 }
 932 
 933 
 934 #ifndef PRODUCT
 935 // print information about reallocated objects
 936 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
 937   fieldDescriptor fd;
 938 
 939   for (int i = 0; i < objects->length(); i++) {
 940     ObjectValue* sv = (ObjectValue*) objects->at(i);
 941     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 942     Handle obj = sv->value();
 943 
 944     tty->print("     object <" INTPTR_FORMAT "> of type ", (void *)sv->value()());
 945     k->print_value();
 946     tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
 947     tty->cr();
 948 
 949     if (Verbose) {
 950       k->oop_print_on(obj(), tty);
 951     }
 952   }
 953 }
 954 #endif
 955 #endif // COMPILER2
 956 
 957 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
 958   Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
 959 
 960 #ifndef PRODUCT
 961   if (TraceDeoptimization) {
 962     ttyLocker ttyl;
 963     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
 964     fr.print_on(tty);
 965     tty->print_cr("     Virtual frames (innermost first):");
 966     for (int index = 0; index < chunk->length(); index++) {
 967       compiledVFrame* vf = chunk->at(index);
 968       tty->print("       %2d - ", index);
 969       vf->print_value();
 970       int bci = chunk->at(index)->raw_bci();
 971       const char* code_name;
 972       if (bci == SynchronizationEntryBCI) {
 973         code_name = "sync entry";
 974       } else {
 975         Bytecodes::Code code = vf->method()->code_at(bci);
 976         code_name = Bytecodes::name(code);
 977       }
 978       tty->print(" - %s", code_name);
 979       tty->print_cr(" @ bci %d ", bci);
 980       if (Verbose) {
 981         vf->print();
 982         tty->cr();
 983       }
 984     }
 985   }
 986 #endif
 987 
 988   // Register map for next frame (used for stack crawl).  We capture
 989   // the state of the deopt'ing frame's caller.  Thus if we need to
 990   // stuff a C2I adapter we can properly fill in the callee-save
 991   // register locations.
 992   frame caller = fr.sender(reg_map);
 993   int frame_size = caller.sp() - fr.sp();
 994 
 995   frame sender = caller;
 996 
 997   // Since the Java thread being deoptimized will eventually adjust it's own stack,
 998   // the vframeArray containing the unpacking information is allocated in the C heap.
 999   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1000   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1001 
1002   // Compare the vframeArray to the collected vframes
1003   assert(array->structural_compare(thread, chunk), "just checking");
1004 
1005 #ifndef PRODUCT
1006   if (TraceDeoptimization) {
1007     ttyLocker ttyl;
1008     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, array);
1009   }
1010 #endif // PRODUCT
1011 
1012   return array;
1013 }
1014 
1015 
1016 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1017   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1018   for (int i = 0; i < monitors->length(); i++) {
1019     MonitorInfo* mon_info = monitors->at(i);
1020     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1021       objects_to_revoke->append(Handle(mon_info->owner()));
1022     }
1023   }
1024 }
1025 
1026 
1027 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1028   if (!UseBiasedLocking) {
1029     return;
1030   }
1031 
1032   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1033 
1034   // Unfortunately we don't have a RegisterMap available in most of
1035   // the places we want to call this routine so we need to walk the
1036   // stack again to update the register map.
1037   if (map == NULL || !map->update_map()) {
1038     StackFrameStream sfs(thread, true);
1039     bool found = false;
1040     while (!found && !sfs.is_done()) {
1041       frame* cur = sfs.current();
1042       sfs.next();
1043       found = cur->id() == fr.id();
1044     }
1045     assert(found, "frame to be deoptimized not found on target thread's stack");
1046     map = sfs.register_map();
1047   }
1048 
1049   vframe* vf = vframe::new_vframe(&fr, map, thread);
1050   compiledVFrame* cvf = compiledVFrame::cast(vf);
1051   // Revoke monitors' biases in all scopes
1052   while (!cvf->is_top()) {
1053     collect_monitors(cvf, objects_to_revoke);
1054     cvf = compiledVFrame::cast(cvf->sender());
1055   }
1056   collect_monitors(cvf, objects_to_revoke);
1057 
1058   if (SafepointSynchronize::is_at_safepoint()) {
1059     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1060   } else {
1061     BiasedLocking::revoke(objects_to_revoke);
1062   }
1063 }
1064 
1065 
1066 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1067   if (!UseBiasedLocking) {
1068     return;
1069   }
1070 
1071   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1072   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1073   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1074     if (jt->has_last_Java_frame()) {
1075       StackFrameStream sfs(jt, true);
1076       while (!sfs.is_done()) {
1077         frame* cur = sfs.current();
1078         if (cb->contains(cur->pc())) {
1079           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1080           compiledVFrame* cvf = compiledVFrame::cast(vf);
1081           // Revoke monitors' biases in all scopes
1082           while (!cvf->is_top()) {
1083             collect_monitors(cvf, objects_to_revoke);
1084             cvf = compiledVFrame::cast(cvf->sender());
1085           }
1086           collect_monitors(cvf, objects_to_revoke);
1087         }
1088         sfs.next();
1089       }
1090     }
1091   }
1092   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1093 }
1094 
1095 
1096 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1097   assert(fr.can_be_deoptimized(), "checking frame type");
1098 
1099   gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1100 
1101   // Patch the nmethod so that when execution returns to it we will
1102   // deopt the execution state and return to the interpreter.
1103   fr.deoptimize(thread);
1104 }
1105 
1106 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1107   // Deoptimize only if the frame comes from compile code.
1108   // Do not deoptimize the frame which is already patched
1109   // during the execution of the loops below.
1110   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1111     return;
1112   }
1113   ResourceMark rm;
1114   DeoptimizationMarker dm;
1115   if (UseBiasedLocking) {
1116     revoke_biases_of_monitors(thread, fr, map);
1117   }
1118   deoptimize_single_frame(thread, fr);
1119 
1120 }
1121 
1122 
1123 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1124   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1125          "can only deoptimize other thread at a safepoint");
1126   // Compute frame and register map based on thread and sp.
1127   RegisterMap reg_map(thread, UseBiasedLocking);
1128   frame fr = thread->last_frame();
1129   while (fr.id() != id) {
1130     fr = fr.sender(&reg_map);
1131   }
1132   deoptimize(thread, fr, &reg_map);
1133 }
1134 
1135 
1136 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1137   if (thread == Thread::current()) {
1138     Deoptimization::deoptimize_frame_internal(thread, id);
1139   } else {
1140     VM_DeoptimizeFrame deopt(thread, id);
1141     VMThread::execute(&deopt);
1142   }
1143 }
1144 
1145 
1146 // JVMTI PopFrame support
1147 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1148 {
1149   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1150 }
1151 JRT_END
1152 
1153 MethodData*
1154 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1155                                 bool create_if_missing) {
1156   Thread* THREAD = thread;
1157   MethodData* mdo = m()->method_data();
1158   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1159     // Build an MDO.  Ignore errors like OutOfMemory;
1160     // that simply means we won't have an MDO to update.
1161     Method::build_interpreter_method_data(m, THREAD);
1162     if (HAS_PENDING_EXCEPTION) {
1163       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1164       CLEAR_PENDING_EXCEPTION;
1165     }
1166     mdo = m()->method_data();
1167   }
1168   return mdo;
1169 }
1170 
1171 #if defined(COMPILER2) || defined(SHARK)
1172 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1173   // in case of an unresolved klass entry, load the class.
1174   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1175     Klass* tk = constant_pool->klass_at(index, CHECK);
1176     return;
1177   }
1178 
1179   if (!constant_pool->tag_at(index).is_symbol()) return;
1180 
1181   Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1182   Symbol*  symbol  = constant_pool->symbol_at(index);
1183 
1184   // class name?
1185   if (symbol->byte_at(0) != '(') {
1186     Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1187     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1188     return;
1189   }
1190 
1191   // then it must be a signature!
1192   ResourceMark rm(THREAD);
1193   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1194     if (ss.is_object()) {
1195       Symbol* class_name = ss.as_symbol(CHECK);
1196       Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1197       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1198     }
1199   }
1200 }
1201 
1202 
1203 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1204   EXCEPTION_MARK;
1205   load_class_by_index(constant_pool, index, THREAD);
1206   if (HAS_PENDING_EXCEPTION) {
1207     // Exception happened during classloading. We ignore the exception here, since it
1208     // is going to be rethrown since the current activation is going to be deoptimized and
1209     // the interpreter will re-execute the bytecode.
1210     CLEAR_PENDING_EXCEPTION;
1211     // Class loading called java code which may have caused a stack
1212     // overflow. If the exception was thrown right before the return
1213     // to the runtime the stack is no longer guarded. Reguard the
1214     // stack otherwise if we return to the uncommon trap blob and the
1215     // stack bang causes a stack overflow we crash.
1216     assert(THREAD->is_Java_thread(), "only a java thread can be here");
1217     JavaThread* thread = (JavaThread*)THREAD;
1218     bool guard_pages_enabled = thread->stack_yellow_zone_enabled();
1219     if (!guard_pages_enabled) guard_pages_enabled = thread->reguard_stack();
1220     assert(guard_pages_enabled, "stack banging in uncommon trap blob may cause crash");
1221   }
1222 }
1223 
1224 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1225   HandleMark hm;
1226 
1227   // uncommon_trap() is called at the beginning of the uncommon trap
1228   // handler. Note this fact before we start generating temporary frames
1229   // that can confuse an asynchronous stack walker. This counter is
1230   // decremented at the end of unpack_frames().
1231   thread->inc_in_deopt_handler();
1232 
1233   // We need to update the map if we have biased locking.
1234   RegisterMap reg_map(thread, UseBiasedLocking);
1235   frame stub_frame = thread->last_frame();
1236   frame fr = stub_frame.sender(&reg_map);
1237   // Make sure the calling nmethod is not getting deoptimized and removed
1238   // before we are done with it.
1239   nmethodLocker nl(fr.pc());
1240 
1241   // Log a message
1242   Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1243               trap_request, fr.pc());
1244 
1245   {
1246     ResourceMark rm;
1247 
1248     // Revoke biases of any monitors in the frame to ensure we can migrate them
1249     revoke_biases_of_monitors(thread, fr, &reg_map);
1250 
1251     DeoptReason reason = trap_request_reason(trap_request);
1252     DeoptAction action = trap_request_action(trap_request);
1253     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1254 
1255     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
1256     compiledVFrame* cvf = compiledVFrame::cast(vf);
1257 
1258     nmethod* nm = cvf->code();
1259 
1260     ScopeDesc*      trap_scope  = cvf->scope();
1261     methodHandle    trap_method = trap_scope->method();
1262     int             trap_bci    = trap_scope->bci();
1263     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
1264 
1265     // Record this event in the histogram.
1266     gather_statistics(reason, action, trap_bc);
1267 
1268     // Ensure that we can record deopt. history:
1269     // Need MDO to record RTM code generation state.
1270     bool create_if_missing = ProfileTraps || UseCodeAging RTM_OPT_ONLY( || UseRTMLocking );
1271 
1272     MethodData* trap_mdo =
1273       get_method_data(thread, trap_method, create_if_missing);
1274 
1275     // Log a message
1276     Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1277                               trap_reason_name(reason), trap_action_name(action), fr.pc(),
1278                               trap_method->name_and_sig_as_C_string(), trap_bci);
1279 
1280     // Print a bunch of diagnostics, if requested.
1281     if (TraceDeoptimization || LogCompilation) {
1282       ResourceMark rm;
1283       ttyLocker ttyl;
1284       char buf[100];
1285       if (xtty != NULL) {
1286         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1287                          os::current_thread_id(),
1288                          format_trap_request(buf, sizeof(buf), trap_request));
1289         nm->log_identity(xtty);
1290       }
1291       Symbol* class_name = NULL;
1292       bool unresolved = false;
1293       if (unloaded_class_index >= 0) {
1294         constantPoolHandle constants (THREAD, trap_method->constants());
1295         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1296           class_name = constants->klass_name_at(unloaded_class_index);
1297           unresolved = true;
1298           if (xtty != NULL)
1299             xtty->print(" unresolved='1'");
1300         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1301           class_name = constants->symbol_at(unloaded_class_index);
1302         }
1303         if (xtty != NULL)
1304           xtty->name(class_name);
1305       }
1306       if (xtty != NULL && trap_mdo != NULL && (int)reason < (int)MethodData::_trap_hist_limit) {
1307         // Dump the relevant MDO state.
1308         // This is the deopt count for the current reason, any previous
1309         // reasons or recompiles seen at this point.
1310         int dcnt = trap_mdo->trap_count(reason);
1311         if (dcnt != 0)
1312           xtty->print(" count='%d'", dcnt);
1313         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1314         int dos = (pdata == NULL)? 0: pdata->trap_state();
1315         if (dos != 0) {
1316           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1317           if (trap_state_is_recompiled(dos)) {
1318             int recnt2 = trap_mdo->overflow_recompile_count();
1319             if (recnt2 != 0)
1320               xtty->print(" recompiles2='%d'", recnt2);
1321           }
1322         }
1323       }
1324       if (xtty != NULL) {
1325         xtty->stamp();
1326         xtty->end_head();
1327       }
1328       if (TraceDeoptimization) {  // make noise on the tty
1329         tty->print("Uncommon trap occurred in");
1330         nm->method()->print_short_name(tty);
1331         tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1332                    fr.pc(),
1333                    os::current_thread_id(),
1334                    trap_reason_name(reason),
1335                    trap_action_name(action),
1336                    unloaded_class_index);
1337         if (class_name != NULL) {
1338           tty->print(unresolved ? " unresolved class: " : " symbol: ");
1339           class_name->print_symbol_on(tty);
1340         }
1341         tty->cr();
1342       }
1343       if (xtty != NULL) {
1344         // Log the precise location of the trap.
1345         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1346           xtty->begin_elem("jvms bci='%d'", sd->bci());
1347           xtty->method(sd->method());
1348           xtty->end_elem();
1349           if (sd->is_top())  break;
1350         }
1351         xtty->tail("uncommon_trap");
1352       }
1353     }
1354     // (End diagnostic printout.)
1355 
1356     // Load class if necessary
1357     if (unloaded_class_index >= 0) {
1358       constantPoolHandle constants(THREAD, trap_method->constants());
1359       load_class_by_index(constants, unloaded_class_index);
1360     }
1361 
1362     // Flush the nmethod if necessary and desirable.
1363     //
1364     // We need to avoid situations where we are re-flushing the nmethod
1365     // because of a hot deoptimization site.  Repeated flushes at the same
1366     // point need to be detected by the compiler and avoided.  If the compiler
1367     // cannot avoid them (or has a bug and "refuses" to avoid them), this
1368     // module must take measures to avoid an infinite cycle of recompilation
1369     // and deoptimization.  There are several such measures:
1370     //
1371     //   1. If a recompilation is ordered a second time at some site X
1372     //   and for the same reason R, the action is adjusted to 'reinterpret',
1373     //   to give the interpreter time to exercise the method more thoroughly.
1374     //   If this happens, the method's overflow_recompile_count is incremented.
1375     //
1376     //   2. If the compiler fails to reduce the deoptimization rate, then
1377     //   the method's overflow_recompile_count will begin to exceed the set
1378     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
1379     //   is adjusted to 'make_not_compilable', and the method is abandoned
1380     //   to the interpreter.  This is a performance hit for hot methods,
1381     //   but is better than a disastrous infinite cycle of recompilations.
1382     //   (Actually, only the method containing the site X is abandoned.)
1383     //
1384     //   3. In parallel with the previous measures, if the total number of
1385     //   recompilations of a method exceeds the much larger set limit
1386     //   PerMethodRecompilationCutoff, the method is abandoned.
1387     //   This should only happen if the method is very large and has
1388     //   many "lukewarm" deoptimizations.  The code which enforces this
1389     //   limit is elsewhere (class nmethod, class Method).
1390     //
1391     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1392     // to recompile at each bytecode independently of the per-BCI cutoff.
1393     //
1394     // The decision to update code is up to the compiler, and is encoded
1395     // in the Action_xxx code.  If the compiler requests Action_none
1396     // no trap state is changed, no compiled code is changed, and the
1397     // computation suffers along in the interpreter.
1398     //
1399     // The other action codes specify various tactics for decompilation
1400     // and recompilation.  Action_maybe_recompile is the loosest, and
1401     // allows the compiled code to stay around until enough traps are seen,
1402     // and until the compiler gets around to recompiling the trapping method.
1403     //
1404     // The other actions cause immediate removal of the present code.
1405 
1406     bool update_trap_state = (reason != Reason_tenured);
1407     bool make_not_entrant = false;
1408     bool make_not_compilable = false;
1409     bool reprofile = false;
1410     switch (action) {
1411     case Action_none:
1412       // Keep the old code.
1413       update_trap_state = false;
1414       break;
1415     case Action_maybe_recompile:
1416       // Do not need to invalidate the present code, but we can
1417       // initiate another
1418       // Start compiler without (necessarily) invalidating the nmethod.
1419       // The system will tolerate the old code, but new code should be
1420       // generated when possible.
1421       break;
1422     case Action_reinterpret:
1423       // Go back into the interpreter for a while, and then consider
1424       // recompiling form scratch.
1425       make_not_entrant = true;
1426       // Reset invocation counter for outer most method.
1427       // This will allow the interpreter to exercise the bytecodes
1428       // for a while before recompiling.
1429       // By contrast, Action_make_not_entrant is immediate.
1430       //
1431       // Note that the compiler will track null_check, null_assert,
1432       // range_check, and class_check events and log them as if they
1433       // had been traps taken from compiled code.  This will update
1434       // the MDO trap history so that the next compilation will
1435       // properly detect hot trap sites.
1436       reprofile = true;
1437       break;
1438     case Action_make_not_entrant:
1439       // Request immediate recompilation, and get rid of the old code.
1440       // Make them not entrant, so next time they are called they get
1441       // recompiled.  Unloaded classes are loaded now so recompile before next
1442       // time they are called.  Same for uninitialized.  The interpreter will
1443       // link the missing class, if any.
1444       make_not_entrant = true;
1445       break;
1446     case Action_make_not_compilable:
1447       // Give up on compiling this method at all.
1448       make_not_entrant = true;
1449       make_not_compilable = true;
1450       break;
1451     default:
1452       ShouldNotReachHere();
1453     }
1454 
1455     // Setting +ProfileTraps fixes the following, on all platforms:
1456     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
1457     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1458     // recompile relies on a MethodData* to record heroic opt failures.
1459 
1460     // Whether the interpreter is producing MDO data or not, we also need
1461     // to use the MDO to detect hot deoptimization points and control
1462     // aggressive optimization.
1463     bool inc_recompile_count = false;
1464     ProfileData* pdata = NULL;
1465     if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1466       assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1467       uint this_trap_count = 0;
1468       bool maybe_prior_trap = false;
1469       bool maybe_prior_recompile = false;
1470       pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1471                                    nm->method(),
1472                                    //outputs:
1473                                    this_trap_count,
1474                                    maybe_prior_trap,
1475                                    maybe_prior_recompile);
1476       // Because the interpreter also counts null, div0, range, and class
1477       // checks, these traps from compiled code are double-counted.
1478       // This is harmless; it just means that the PerXTrapLimit values
1479       // are in effect a little smaller than they look.
1480 
1481       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1482       if (per_bc_reason != Reason_none) {
1483         // Now take action based on the partially known per-BCI history.
1484         if (maybe_prior_trap
1485             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1486           // If there are too many traps at this BCI, force a recompile.
1487           // This will allow the compiler to see the limit overflow, and
1488           // take corrective action, if possible.  The compiler generally
1489           // does not use the exact PerBytecodeTrapLimit value, but instead
1490           // changes its tactics if it sees any traps at all.  This provides
1491           // a little hysteresis, delaying a recompile until a trap happens
1492           // several times.
1493           //
1494           // Actually, since there is only one bit of counter per BCI,
1495           // the possible per-BCI counts are {0,1,(per-method count)}.
1496           // This produces accurate results if in fact there is only
1497           // one hot trap site, but begins to get fuzzy if there are
1498           // many sites.  For example, if there are ten sites each
1499           // trapping two or more times, they each get the blame for
1500           // all of their traps.
1501           make_not_entrant = true;
1502         }
1503 
1504         // Detect repeated recompilation at the same BCI, and enforce a limit.
1505         if (make_not_entrant && maybe_prior_recompile) {
1506           // More than one recompile at this point.
1507           inc_recompile_count = maybe_prior_trap;
1508         }
1509       } else {
1510         // For reasons which are not recorded per-bytecode, we simply
1511         // force recompiles unconditionally.
1512         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1513         make_not_entrant = true;
1514       }
1515 
1516       // Go back to the compiler if there are too many traps in this method.
1517       if (this_trap_count >= per_method_trap_limit(reason)) {
1518         // If there are too many traps in this method, force a recompile.
1519         // This will allow the compiler to see the limit overflow, and
1520         // take corrective action, if possible.
1521         // (This condition is an unlikely backstop only, because the
1522         // PerBytecodeTrapLimit is more likely to take effect first,
1523         // if it is applicable.)
1524         make_not_entrant = true;
1525       }
1526 
1527       // Here's more hysteresis:  If there has been a recompile at
1528       // this trap point already, run the method in the interpreter
1529       // for a while to exercise it more thoroughly.
1530       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1531         reprofile = true;
1532       }
1533     }
1534 
1535     // Take requested actions on the method:
1536 
1537     // Recompile
1538     if (make_not_entrant) {
1539       if (!nm->make_not_entrant()) {
1540         return; // the call did not change nmethod's state
1541       }
1542 
1543       if (pdata != NULL) {
1544         // Record the recompilation event, if any.
1545         int tstate0 = pdata->trap_state();
1546         int tstate1 = trap_state_set_recompiled(tstate0, true);
1547         if (tstate1 != tstate0)
1548           pdata->set_trap_state(tstate1);
1549       }
1550 
1551 #if INCLUDE_RTM_OPT
1552       // Restart collecting RTM locking abort statistic if the method
1553       // is recompiled for a reason other than RTM state change.
1554       // Assume that in new recompiled code the statistic could be different,
1555       // for example, due to different inlining.
1556       if ((reason != Reason_rtm_state_change) && (trap_mdo != NULL) &&
1557           UseRTMDeopt && (nm->rtm_state() != ProfileRTM)) {
1558         trap_mdo->atomic_set_rtm_state(ProfileRTM);
1559       }
1560 #endif
1561       // For code aging we count traps separately here, using make_not_entrant()
1562       // as a guard against simultaneous deopts in multiple threads.
1563       if (reason == Reason_tenured && trap_mdo != NULL) {
1564         trap_mdo->inc_tenure_traps();
1565       }
1566     }
1567 
1568     if (inc_recompile_count) {
1569       trap_mdo->inc_overflow_recompile_count();
1570       if ((uint)trap_mdo->overflow_recompile_count() >
1571           (uint)PerBytecodeRecompilationCutoff) {
1572         // Give up on the method containing the bad BCI.
1573         if (trap_method() == nm->method()) {
1574           make_not_compilable = true;
1575         } else {
1576           trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1577           // But give grace to the enclosing nm->method().
1578         }
1579       }
1580     }
1581 
1582     // Reprofile
1583     if (reprofile) {
1584       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1585     }
1586 
1587     // Give up compiling
1588     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1589       assert(make_not_entrant, "consistent");
1590       nm->method()->set_not_compilable(CompLevel_full_optimization);
1591     }
1592 
1593   } // Free marked resources
1594 
1595 }
1596 JRT_END
1597 
1598 ProfileData*
1599 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1600                                          int trap_bci,
1601                                          Deoptimization::DeoptReason reason,
1602                                          Method* compiled_method,
1603                                          //outputs:
1604                                          uint& ret_this_trap_count,
1605                                          bool& ret_maybe_prior_trap,
1606                                          bool& ret_maybe_prior_recompile) {
1607   uint prior_trap_count = trap_mdo->trap_count(reason);
1608   uint this_trap_count  = trap_mdo->inc_trap_count(reason);
1609 
1610   // If the runtime cannot find a place to store trap history,
1611   // it is estimated based on the general condition of the method.
1612   // If the method has ever been recompiled, or has ever incurred
1613   // a trap with the present reason , then this BCI is assumed
1614   // (pessimistically) to be the culprit.
1615   bool maybe_prior_trap      = (prior_trap_count != 0);
1616   bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1617   ProfileData* pdata = NULL;
1618 
1619 
1620   // For reasons which are recorded per bytecode, we check per-BCI data.
1621   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1622   if (per_bc_reason != Reason_none) {
1623     // Find the profile data for this BCI.  If there isn't one,
1624     // try to allocate one from the MDO's set of spares.
1625     // This will let us detect a repeated trap at this point.
1626     pdata = trap_mdo->allocate_bci_to_data(trap_bci, reason_is_speculate(reason) ? compiled_method : NULL);
1627 
1628     if (pdata != NULL) {
1629       if (reason_is_speculate(reason) && !pdata->is_SpeculativeTrapData()) {
1630         if (LogCompilation && xtty != NULL) {
1631           ttyLocker ttyl;
1632           // no more room for speculative traps in this MDO
1633           xtty->elem("speculative_traps_oom");
1634         }
1635       }
1636       // Query the trap state of this profile datum.
1637       int tstate0 = pdata->trap_state();
1638       if (!trap_state_has_reason(tstate0, per_bc_reason))
1639         maybe_prior_trap = false;
1640       if (!trap_state_is_recompiled(tstate0))
1641         maybe_prior_recompile = false;
1642 
1643       // Update the trap state of this profile datum.
1644       int tstate1 = tstate0;
1645       // Record the reason.
1646       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1647       // Store the updated state on the MDO, for next time.
1648       if (tstate1 != tstate0)
1649         pdata->set_trap_state(tstate1);
1650     } else {
1651       if (LogCompilation && xtty != NULL) {
1652         ttyLocker ttyl;
1653         // Missing MDP?  Leave a small complaint in the log.
1654         xtty->elem("missing_mdp bci='%d'", trap_bci);
1655       }
1656     }
1657   }
1658 
1659   // Return results:
1660   ret_this_trap_count = this_trap_count;
1661   ret_maybe_prior_trap = maybe_prior_trap;
1662   ret_maybe_prior_recompile = maybe_prior_recompile;
1663   return pdata;
1664 }
1665 
1666 void
1667 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1668   ResourceMark rm;
1669   // Ignored outputs:
1670   uint ignore_this_trap_count;
1671   bool ignore_maybe_prior_trap;
1672   bool ignore_maybe_prior_recompile;
1673   assert(!reason_is_speculate(reason), "reason speculate only used by compiler");
1674   query_update_method_data(trap_mdo, trap_bci,
1675                            (DeoptReason)reason,
1676                            NULL,
1677                            ignore_this_trap_count,
1678                            ignore_maybe_prior_trap,
1679                            ignore_maybe_prior_recompile);
1680 }
1681 
1682 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1683 
1684   // Still in Java no safepoints
1685   {
1686     // This enters VM and may safepoint
1687     uncommon_trap_inner(thread, trap_request);
1688   }
1689   return fetch_unroll_info_helper(thread);
1690 }
1691 
1692 // Local derived constants.
1693 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1694 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
1695 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1696 
1697 //---------------------------trap_state_reason---------------------------------
1698 Deoptimization::DeoptReason
1699 Deoptimization::trap_state_reason(int trap_state) {
1700   // This assert provides the link between the width of DataLayout::trap_bits
1701   // and the encoding of "recorded" reasons.  It ensures there are enough
1702   // bits to store all needed reasons in the per-BCI MDO profile.
1703   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1704   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1705   trap_state -= recompile_bit;
1706   if (trap_state == DS_REASON_MASK) {
1707     return Reason_many;
1708   } else {
1709     assert((int)Reason_none == 0, "state=0 => Reason_none");
1710     return (DeoptReason)trap_state;
1711   }
1712 }
1713 //-------------------------trap_state_has_reason-------------------------------
1714 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1715   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1716   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1717   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1718   trap_state -= recompile_bit;
1719   if (trap_state == DS_REASON_MASK) {
1720     return -1;  // true, unspecifically (bottom of state lattice)
1721   } else if (trap_state == reason) {
1722     return 1;   // true, definitely
1723   } else if (trap_state == 0) {
1724     return 0;   // false, definitely (top of state lattice)
1725   } else {
1726     return 0;   // false, definitely
1727   }
1728 }
1729 //-------------------------trap_state_add_reason-------------------------------
1730 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1731   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1732   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1733   trap_state -= recompile_bit;
1734   if (trap_state == DS_REASON_MASK) {
1735     return trap_state + recompile_bit;     // already at state lattice bottom
1736   } else if (trap_state == reason) {
1737     return trap_state + recompile_bit;     // the condition is already true
1738   } else if (trap_state == 0) {
1739     return reason + recompile_bit;          // no condition has yet been true
1740   } else {
1741     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
1742   }
1743 }
1744 //-----------------------trap_state_is_recompiled------------------------------
1745 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1746   return (trap_state & DS_RECOMPILE_BIT) != 0;
1747 }
1748 //-----------------------trap_state_set_recompiled-----------------------------
1749 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1750   if (z)  return trap_state |  DS_RECOMPILE_BIT;
1751   else    return trap_state & ~DS_RECOMPILE_BIT;
1752 }
1753 //---------------------------format_trap_state---------------------------------
1754 // This is used for debugging and diagnostics, including LogFile output.
1755 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1756                                               int trap_state) {
1757   DeoptReason reason      = trap_state_reason(trap_state);
1758   bool        recomp_flag = trap_state_is_recompiled(trap_state);
1759   // Re-encode the state from its decoded components.
1760   int decoded_state = 0;
1761   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1762     decoded_state = trap_state_add_reason(decoded_state, reason);
1763   if (recomp_flag)
1764     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1765   // If the state re-encodes properly, format it symbolically.
1766   // Because this routine is used for debugging and diagnostics,
1767   // be robust even if the state is a strange value.
1768   size_t len;
1769   if (decoded_state != trap_state) {
1770     // Random buggy state that doesn't decode??
1771     len = jio_snprintf(buf, buflen, "#%d", trap_state);
1772   } else {
1773     len = jio_snprintf(buf, buflen, "%s%s",
1774                        trap_reason_name(reason),
1775                        recomp_flag ? " recompiled" : "");
1776   }
1777   if (len >= buflen)
1778     buf[buflen-1] = '\0';
1779   return buf;
1780 }
1781 
1782 
1783 //--------------------------------statics--------------------------------------
1784 const char* Deoptimization::_trap_reason_name[] = {
1785   // Note:  Keep this in sync. with enum DeoptReason.
1786   "none",
1787   "null_check",
1788   "null_assert",
1789   "range_check",
1790   "class_check",
1791   "array_check",
1792   "intrinsic",
1793   "bimorphic",
1794   "unloaded",
1795   "uninitialized",
1796   "unreached",
1797   "unhandled",
1798   "constraint",
1799   "div0_check",
1800   "age",
1801   "predicate",
1802   "loop_limit_check",
1803   "speculate_class_check",
1804   "speculate_null_check",
1805   "rtm_state_change",
1806   "unstable_if",
1807   "tenured"
1808 };
1809 const char* Deoptimization::_trap_action_name[] = {
1810   // Note:  Keep this in sync. with enum DeoptAction.
1811   "none",
1812   "maybe_recompile",
1813   "reinterpret",
1814   "make_not_entrant",
1815   "make_not_compilable"
1816 };
1817 
1818 const char* Deoptimization::trap_reason_name(int reason) {
1819   // Check that every reason has a name
1820   STATIC_ASSERT(sizeof(_trap_reason_name)/sizeof(const char*) == Reason_LIMIT);
1821 
1822   if (reason == Reason_many)  return "many";
1823   if ((uint)reason < Reason_LIMIT)
1824     return _trap_reason_name[reason];
1825   static char buf[20];
1826   sprintf(buf, "reason%d", reason);
1827   return buf;
1828 }
1829 const char* Deoptimization::trap_action_name(int action) {
1830   // Check that every action has a name
1831   STATIC_ASSERT(sizeof(_trap_action_name)/sizeof(const char*) == Action_LIMIT);
1832 
1833   if ((uint)action < Action_LIMIT)
1834     return _trap_action_name[action];
1835   static char buf[20];
1836   sprintf(buf, "action%d", action);
1837   return buf;
1838 }
1839 
1840 // This is used for debugging and diagnostics, including LogFile output.
1841 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1842                                                 int trap_request) {
1843   jint unloaded_class_index = trap_request_index(trap_request);
1844   const char* reason = trap_reason_name(trap_request_reason(trap_request));
1845   const char* action = trap_action_name(trap_request_action(trap_request));
1846   size_t len;
1847   if (unloaded_class_index < 0) {
1848     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1849                        reason, action);
1850   } else {
1851     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1852                        reason, action, unloaded_class_index);
1853   }
1854   if (len >= buflen)
1855     buf[buflen-1] = '\0';
1856   return buf;
1857 }
1858 
1859 juint Deoptimization::_deoptimization_hist
1860         [Deoptimization::Reason_LIMIT]
1861     [1 + Deoptimization::Action_LIMIT]
1862         [Deoptimization::BC_CASE_LIMIT]
1863   = {0};
1864 
1865 enum {
1866   LSB_BITS = 8,
1867   LSB_MASK = right_n_bits(LSB_BITS)
1868 };
1869 
1870 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1871                                        Bytecodes::Code bc) {
1872   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1873   assert(action >= 0 && action < Action_LIMIT, "oob");
1874   _deoptimization_hist[Reason_none][0][0] += 1;  // total
1875   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
1876   juint* cases = _deoptimization_hist[reason][1+action];
1877   juint* bc_counter_addr = NULL;
1878   juint  bc_counter      = 0;
1879   // Look for an unused counter, or an exact match to this BC.
1880   if (bc != Bytecodes::_illegal) {
1881     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1882       juint* counter_addr = &cases[bc_case];
1883       juint  counter = *counter_addr;
1884       if ((counter == 0 && bc_counter_addr == NULL)
1885           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1886         // this counter is either free or is already devoted to this BC
1887         bc_counter_addr = counter_addr;
1888         bc_counter = counter | bc;
1889       }
1890     }
1891   }
1892   if (bc_counter_addr == NULL) {
1893     // Overflow, or no given bytecode.
1894     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1895     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
1896   }
1897   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1898 }
1899 
1900 jint Deoptimization::total_deoptimization_count() {
1901   return _deoptimization_hist[Reason_none][0][0];
1902 }
1903 
1904 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1905   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1906   return _deoptimization_hist[reason][0][0];
1907 }
1908 
1909 void Deoptimization::print_statistics() {
1910   juint total = total_deoptimization_count();
1911   juint account = total;
1912   if (total != 0) {
1913     ttyLocker ttyl;
1914     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
1915     tty->print_cr("Deoptimization traps recorded:");
1916     #define PRINT_STAT_LINE(name, r) \
1917       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1918     PRINT_STAT_LINE("total", total);
1919     // For each non-zero entry in the histogram, print the reason,
1920     // the action, and (if specifically known) the type of bytecode.
1921     for (int reason = 0; reason < Reason_LIMIT; reason++) {
1922       for (int action = 0; action < Action_LIMIT; action++) {
1923         juint* cases = _deoptimization_hist[reason][1+action];
1924         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1925           juint counter = cases[bc_case];
1926           if (counter != 0) {
1927             char name[1*K];
1928             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1929             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1930               bc = Bytecodes::_illegal;
1931             sprintf(name, "%s/%s/%s",
1932                     trap_reason_name(reason),
1933                     trap_action_name(action),
1934                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1935             juint r = counter >> LSB_BITS;
1936             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1937             account -= r;
1938           }
1939         }
1940       }
1941     }
1942     if (account != 0) {
1943       PRINT_STAT_LINE("unaccounted", account);
1944     }
1945     #undef PRINT_STAT_LINE
1946     if (xtty != NULL)  xtty->tail("statistics");
1947   }
1948 }
1949 #else // COMPILER2 || SHARK
1950 
1951 
1952 // Stubs for C1 only system.
1953 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1954   return false;
1955 }
1956 
1957 const char* Deoptimization::trap_reason_name(int reason) {
1958   return "unknown";
1959 }
1960 
1961 void Deoptimization::print_statistics() {
1962   // no output
1963 }
1964 
1965 void
1966 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1967   // no udpate
1968 }
1969 
1970 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1971   return 0;
1972 }
1973 
1974 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1975                                        Bytecodes::Code bc) {
1976   // no update
1977 }
1978 
1979 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1980                                               int trap_state) {
1981   jio_snprintf(buf, buflen, "#%d", trap_state);
1982   return buf;
1983 }
1984 
1985 #endif // COMPILER2 || SHARK