1 /*
   2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "classfile/systemDictionary.hpp"
  27 #include "code/debugInfoRec.hpp"
  28 #include "code/nmethod.hpp"
  29 #include "code/pcDesc.hpp"
  30 #include "code/scopeDesc.hpp"
  31 #include "interpreter/bytecode.hpp"
  32 #include "interpreter/interpreter.hpp"
  33 #include "interpreter/oopMapCache.hpp"
  34 #include "memory/allocation.inline.hpp"
  35 #include "memory/oopFactory.hpp"
  36 #include "memory/resourceArea.hpp"
  37 #include "oops/methodOop.hpp"
  38 #include "oops/oop.inline.hpp"
  39 #include "prims/jvmtiThreadState.hpp"
  40 #include "runtime/biasedLocking.hpp"
  41 #include "runtime/compilationPolicy.hpp"
  42 #include "runtime/deoptimization.hpp"
  43 #include "runtime/interfaceSupport.hpp"
  44 #include "runtime/sharedRuntime.hpp"
  45 #include "runtime/signature.hpp"
  46 #include "runtime/stubRoutines.hpp"
  47 #include "runtime/thread.hpp"
  48 #include "runtime/vframe.hpp"
  49 #include "runtime/vframeArray.hpp"
  50 #include "runtime/vframe_hp.hpp"
  51 #include "utilities/events.hpp"
  52 #include "utilities/xmlstream.hpp"
  53 #ifdef TARGET_ARCH_x86
  54 # include "vmreg_x86.inline.hpp"
  55 #endif
  56 #ifdef TARGET_ARCH_sparc
  57 # include "vmreg_sparc.inline.hpp"
  58 #endif
  59 #ifdef TARGET_ARCH_zero
  60 # include "vmreg_zero.inline.hpp"
  61 #endif
  62 #ifdef TARGET_ARCH_arm
  63 # include "vmreg_arm.inline.hpp"
  64 #endif
  65 #ifdef TARGET_ARCH_ppc
  66 # include "vmreg_ppc.inline.hpp"
  67 #endif
  68 #ifdef COMPILER2
  69 #ifdef TARGET_ARCH_MODEL_x86_32
  70 # include "adfiles/ad_x86_32.hpp"
  71 #endif
  72 #ifdef TARGET_ARCH_MODEL_x86_64
  73 # include "adfiles/ad_x86_64.hpp"
  74 #endif
  75 #ifdef TARGET_ARCH_MODEL_sparc
  76 # include "adfiles/ad_sparc.hpp"
  77 #endif
  78 #ifdef TARGET_ARCH_MODEL_zero
  79 # include "adfiles/ad_zero.hpp"
  80 #endif
  81 #ifdef TARGET_ARCH_MODEL_arm
  82 # include "adfiles/ad_arm.hpp"
  83 #endif
  84 #ifdef TARGET_ARCH_MODEL_ppc
  85 # include "adfiles/ad_ppc.hpp"
  86 #endif
  87 #endif
  88 
  89 bool DeoptimizationMarker::_is_active = false;
  90 
  91 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
  92                                          int  caller_adjustment,
  93                                          int  number_of_frames,
  94                                          intptr_t* frame_sizes,
  95                                          address* frame_pcs,
  96                                          BasicType return_type) {
  97   _size_of_deoptimized_frame = size_of_deoptimized_frame;
  98   _caller_adjustment         = caller_adjustment;
  99   _number_of_frames          = number_of_frames;
 100   _frame_sizes               = frame_sizes;
 101   _frame_pcs                 = frame_pcs;
 102   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
 103   _return_type               = return_type;
 104   // PD (x86 only)
 105   _counter_temp              = 0;
 106   _initial_fp                = 0;
 107   _unpack_kind               = 0;
 108   _sender_sp_temp            = 0;
 109 
 110   _total_frame_sizes         = size_of_frames();
 111 }
 112 
 113 
 114 Deoptimization::UnrollBlock::~UnrollBlock() {
 115   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
 116   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
 117   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
 118 }
 119 
 120 
 121 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
 122   assert(register_number < RegisterMap::reg_count, "checking register number");
 123   return &_register_block[register_number * 2];
 124 }
 125 
 126 
 127 
 128 int Deoptimization::UnrollBlock::size_of_frames() const {
 129   // Acount first for the adjustment of the initial frame
 130   int result = _caller_adjustment;
 131   for (int index = 0; index < number_of_frames(); index++) {
 132     result += frame_sizes()[index];
 133   }
 134   return result;
 135 }
 136 
 137 
 138 void Deoptimization::UnrollBlock::print() {
 139   ttyLocker ttyl;
 140   tty->print_cr("UnrollBlock");
 141   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 142   tty->print(   "  frame_sizes: ");
 143   for (int index = 0; index < number_of_frames(); index++) {
 144     tty->print("%d ", frame_sizes()[index]);
 145   }
 146   tty->cr();
 147 }
 148 
 149 
 150 // In order to make fetch_unroll_info work properly with escape
 151 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
 152 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
 153 // of previously eliminated objects occurs in realloc_objects, which is
 154 // called from the method fetch_unroll_info_helper below.
 155 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
 156   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 157   // but makes the entry a little slower. There is however a little dance we have to
 158   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 159 
 160   // fetch_unroll_info() is called at the beginning of the deoptimization
 161   // handler. Note this fact before we start generating temporary frames
 162   // that can confuse an asynchronous stack walker. This counter is
 163   // decremented at the end of unpack_frames().
 164   thread->inc_in_deopt_handler();
 165 
 166   return fetch_unroll_info_helper(thread);
 167 JRT_END
 168 
 169 
 170 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 171 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
 172 
 173   // Note: there is a safepoint safety issue here. No matter whether we enter
 174   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 175   // the vframeArray is created.
 176   //
 177 
 178   // Allocate our special deoptimization ResourceMark
 179   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
 180   assert(thread->deopt_mark() == NULL, "Pending deopt!");
 181   thread->set_deopt_mark(dmark);
 182 
 183   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
 184   RegisterMap map(thread, true);
 185   RegisterMap dummy_map(thread, false);
 186   // Now get the deoptee with a valid map
 187   frame deoptee = stub_frame.sender(&map);
 188   // Set the deoptee nmethod
 189   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
 190   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
 191 
 192   // Create a growable array of VFrames where each VFrame represents an inlined
 193   // Java frame.  This storage is allocated with the usual system arena.
 194   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 195   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 196   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
 197   while (!vf->is_top()) {
 198     assert(vf->is_compiled_frame(), "Wrong frame type");
 199     chunk->push(compiledVFrame::cast(vf));
 200     vf = vf->sender();
 201   }
 202   assert(vf->is_compiled_frame(), "Wrong frame type");
 203   chunk->push(compiledVFrame::cast(vf));
 204 
 205 #ifdef COMPILER2
 206   // Reallocate the non-escaping objects and restore their fields. Then
 207   // relock objects if synchronization on them was eliminated.
 208   if (DoEscapeAnalysis) {
 209     if (EliminateAllocations) {
 210       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 211       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 212 
 213       // The flag return_oop() indicates call sites which return oop
 214       // in compiled code. Such sites include java method calls,
 215       // runtime calls (for example, used to allocate new objects/arrays
 216       // on slow code path) and any other calls generated in compiled code.
 217       // It is not guaranteed that we can get such information here only
 218       // by analyzing bytecode in deoptimized frames. This is why this flag
 219       // is set during method compilation (see Compile::Process_OopMap_Node()).
 220       bool save_oop_result = chunk->at(0)->scope()->return_oop();
 221       Handle return_value;
 222       if (save_oop_result) {
 223         // Reallocation may trigger GC. If deoptimization happened on return from
 224         // call which returns oop we need to save it since it is not in oopmap.
 225         oop result = deoptee.saved_oop_result(&map);
 226         assert(result == NULL || result->is_oop(), "must be oop");
 227         return_value = Handle(thread, result);
 228         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 229         if (TraceDeoptimization) {
 230           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
 231         }
 232       }
 233       bool reallocated = false;
 234       if (objects != NULL) {
 235         JRT_BLOCK
 236           reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
 237         JRT_END
 238       }
 239       if (reallocated) {
 240         reassign_fields(&deoptee, &map, objects);
 241 #ifndef PRODUCT
 242         if (TraceDeoptimization) {
 243           ttyLocker ttyl;
 244           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
 245           print_objects(objects);
 246         }
 247 #endif
 248       }
 249       if (save_oop_result) {
 250         // Restore result.
 251         deoptee.set_saved_oop_result(&map, return_value());
 252       }
 253     }
 254     if (EliminateLocks) {
 255 #ifndef PRODUCT
 256       bool first = true;
 257 #endif
 258       for (int i = 0; i < chunk->length(); i++) {
 259         compiledVFrame* cvf = chunk->at(i);
 260         assert (cvf->scope() != NULL,"expect only compiled java frames");
 261         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 262         if (monitors->is_nonempty()) {
 263           relock_objects(monitors, thread);
 264 #ifndef PRODUCT
 265           if (TraceDeoptimization) {
 266             ttyLocker ttyl;
 267             for (int j = 0; j < monitors->length(); j++) {
 268               MonitorInfo* mi = monitors->at(j);
 269               if (mi->eliminated()) {
 270                 if (first) {
 271                   first = false;
 272                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
 273                 }
 274                 tty->print_cr("     object <" INTPTR_FORMAT "> locked", mi->owner());
 275               }
 276             }
 277           }
 278 #endif
 279         }
 280       }
 281     }
 282   }
 283 #endif // COMPILER2
 284   // Ensure that no safepoint is taken after pointers have been stored
 285   // in fields of rematerialized objects.  If a safepoint occurs from here on
 286   // out the java state residing in the vframeArray will be missed.
 287   No_Safepoint_Verifier no_safepoint;
 288 
 289   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
 290 
 291   assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
 292   thread->set_vframe_array_head(array);
 293 
 294   // Now that the vframeArray has been created if we have any deferred local writes
 295   // added by jvmti then we can free up that structure as the data is now in the
 296   // vframeArray
 297 
 298   if (thread->deferred_locals() != NULL) {
 299     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
 300     int i = 0;
 301     do {
 302       // Because of inlining we could have multiple vframes for a single frame
 303       // and several of the vframes could have deferred writes. Find them all.
 304       if (list->at(i)->id() == array->original().id()) {
 305         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
 306         list->remove_at(i);
 307         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
 308         delete dlv;
 309       } else {
 310         i++;
 311       }
 312     } while ( i < list->length() );
 313     if (list->length() == 0) {
 314       thread->set_deferred_locals(NULL);
 315       // free the list and elements back to C heap.
 316       delete list;
 317     }
 318 
 319   }
 320 
 321 #ifndef SHARK
 322   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 323   CodeBlob* cb = stub_frame.cb();
 324   // Verify we have the right vframeArray
 325   assert(cb->frame_size() >= 0, "Unexpected frame size");
 326   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 327 
 328   // If the deopt call site is a MethodHandle invoke call site we have
 329   // to adjust the unpack_sp.
 330   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 331   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 332     unpack_sp = deoptee.unextended_sp();
 333 
 334 #ifdef ASSERT
 335   assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
 336   Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
 337 #endif
 338 #else
 339   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
 340 #endif // !SHARK
 341 
 342   // This is a guarantee instead of an assert because if vframe doesn't match
 343   // we will unpack the wrong deoptimized frame and wind up in strange places
 344   // where it will be very difficult to figure out what went wrong. Better
 345   // to die an early death here than some very obscure death later when the
 346   // trail is cold.
 347   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 348   // in that it will fail to detect a problem when there is one. This needs
 349   // more work in tiger timeframe.
 350   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 351 
 352   int number_of_frames = array->frames();
 353 
 354   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 355   // virtual activation, which is the reverse of the elements in the vframes array.
 356   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
 357   // +1 because we always have an interpreter return address for the final slot.
 358   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
 359   int callee_parameters = 0;
 360   int callee_locals = 0;
 361   int popframe_extra_args = 0;
 362   // Create an interpreter return address for the stub to use as its return
 363   // address so the skeletal frames are perfectly walkable
 364   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 365 
 366   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 367   // activation be put back on the expression stack of the caller for reexecution
 368   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
 369     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
 370   }
 371 
 372   //
 373   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 374   // frame_sizes/frame_pcs[1] next oldest frame (int)
 375   // frame_sizes/frame_pcs[n] youngest frame (int)
 376   //
 377   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 378   // owns the space for the return address to it's caller).  Confusing ain't it.
 379   //
 380   // The vframe array can address vframes with indices running from
 381   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 382   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 383   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 384   // so things look a little strange in this loop.
 385   //
 386   for (int index = 0; index < array->frames(); index++ ) {
 387     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 388     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 389     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 390     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
 391                                                                                                     callee_locals,
 392                                                                                                     index == 0,
 393                                                                                                     popframe_extra_args);
 394     // This pc doesn't have to be perfect just good enough to identify the frame
 395     // as interpreted so the skeleton frame will be walkable
 396     // The correct pc will be set when the skeleton frame is completely filled out
 397     // The final pc we store in the loop is wrong and will be overwritten below
 398     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 399 
 400     callee_parameters = array->element(index)->method()->size_of_parameters();
 401     callee_locals = array->element(index)->method()->max_locals();
 402     popframe_extra_args = 0;
 403   }
 404 
 405   // Compute whether the root vframe returns a float or double value.
 406   BasicType return_type;
 407   {
 408     HandleMark hm;
 409     methodHandle method(thread, array->element(0)->method());
 410     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 411     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 412   }
 413 
 414   // Compute information for handling adapters and adjusting the frame size of the caller.
 415   int caller_adjustment = 0;
 416 
 417   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 418   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 419   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 420   //
 421   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 422   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 423 
 424   // Compute the amount the oldest interpreter frame will have to adjust
 425   // its caller's stack by. If the caller is a compiled frame then
 426   // we pretend that the callee has no parameters so that the
 427   // extension counts for the full amount of locals and not just
 428   // locals-parms. This is because without a c2i adapter the parm
 429   // area as created by the compiled frame will not be usable by
 430   // the interpreter. (Depending on the calling convention there
 431   // may not even be enough space).
 432 
 433   // QQQ I'd rather see this pushed down into last_frame_adjust
 434   // and have it take the sender (aka caller).
 435 
 436   if (deopt_sender.is_compiled_frame()) {
 437     caller_adjustment = last_frame_adjust(0, callee_locals);
 438   } else if (callee_locals > callee_parameters) {
 439     // The caller frame may need extending to accommodate
 440     // non-parameter locals of the first unpacked interpreted frame.
 441     // Compute that adjustment.
 442     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 443   }
 444 
 445 
 446   // If the sender is deoptimized the we must retrieve the address of the handler
 447   // since the frame will "magically" show the original pc before the deopt
 448   // and we'd undo the deopt.
 449 
 450   frame_pcs[0] = deopt_sender.raw_pc();
 451 
 452 #ifndef SHARK
 453   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 454 #endif // SHARK
 455 
 456   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 457                                       caller_adjustment * BytesPerWord,
 458                                       number_of_frames,
 459                                       frame_sizes,
 460                                       frame_pcs,
 461                                       return_type);
 462 #if defined(IA32) || defined(AMD64)
 463   // We need a way to pass fp to the unpacking code so the skeletal frames
 464   // come out correct. This is only needed for x86 because of c2 using ebp
 465   // as an allocatable register. So this update is useless (and harmless)
 466   // on the other platforms. It would be nice to do this in a different
 467   // way but even the old style deoptimization had a problem with deriving
 468   // this value. NEEDS_CLEANUP
 469   // Note: now that c1 is using c2's deopt blob we must do this on all
 470   // x86 based platforms
 471   intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
 472   *fp_addr = array->sender().fp(); // was adapter_caller
 473 #endif /* IA32 || AMD64 */
 474 
 475   if (array->frames() > 1) {
 476     if (VerifyStack && TraceDeoptimization) {
 477       tty->print_cr("Deoptimizing method containing inlining");
 478     }
 479   }
 480 
 481   array->set_unroll_block(info);
 482   return info;
 483 }
 484 
 485 // Called to cleanup deoptimization data structures in normal case
 486 // after unpacking to stack and when stack overflow error occurs
 487 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 488                                         vframeArray *array) {
 489 
 490   // Get array if coming from exception
 491   if (array == NULL) {
 492     array = thread->vframe_array_head();
 493   }
 494   thread->set_vframe_array_head(NULL);
 495 
 496   // Free the previous UnrollBlock
 497   vframeArray* old_array = thread->vframe_array_last();
 498   thread->set_vframe_array_last(array);
 499 
 500   if (old_array != NULL) {
 501     UnrollBlock* old_info = old_array->unroll_block();
 502     old_array->set_unroll_block(NULL);
 503     delete old_info;
 504     delete old_array;
 505   }
 506 
 507   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 508   // inside the vframeArray (StackValueCollections)
 509 
 510   delete thread->deopt_mark();
 511   thread->set_deopt_mark(NULL);
 512   thread->set_deopt_nmethod(NULL);
 513 
 514 
 515   if (JvmtiExport::can_pop_frame()) {
 516 #ifndef CC_INTERP
 517     // Regardless of whether we entered this routine with the pending
 518     // popframe condition bit set, we should always clear it now
 519     thread->clear_popframe_condition();
 520 #else
 521     // C++ interpeter will clear has_pending_popframe when it enters
 522     // with method_resume. For deopt_resume2 we clear it now.
 523     if (thread->popframe_forcing_deopt_reexecution())
 524         thread->clear_popframe_condition();
 525 #endif /* CC_INTERP */
 526   }
 527 
 528   // unpack_frames() is called at the end of the deoptimization handler
 529   // and (in C2) at the end of the uncommon trap handler. Note this fact
 530   // so that an asynchronous stack walker can work again. This counter is
 531   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 532   // the beginning of uncommon_trap().
 533   thread->dec_in_deopt_handler();
 534 }
 535 
 536 
 537 // Return BasicType of value being returned
 538 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 539 
 540   // We are already active int he special DeoptResourceMark any ResourceObj's we
 541   // allocate will be freed at the end of the routine.
 542 
 543   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 544   // but makes the entry a little slower. There is however a little dance we have to
 545   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 546   ResetNoHandleMark rnhm; // No-op in release/product versions
 547   HandleMark hm;
 548 
 549   frame stub_frame = thread->last_frame();
 550 
 551   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 552   // must point to the vframeArray for the unpack frame.
 553   vframeArray* array = thread->vframe_array_head();
 554 
 555 #ifndef PRODUCT
 556   if (TraceDeoptimization) {
 557     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
 558   }
 559 #endif
 560 
 561   UnrollBlock* info = array->unroll_block();
 562 
 563   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 564   array->unpack_to_stack(stub_frame, exec_mode);
 565 
 566   BasicType bt = info->return_type();
 567 
 568   // If we have an exception pending, claim that the return type is an oop
 569   // so the deopt_blob does not overwrite the exception_oop.
 570 
 571   if (exec_mode == Unpack_exception)
 572     bt = T_OBJECT;
 573 
 574   // Cleanup thread deopt data
 575   cleanup_deopt_info(thread, array);
 576 
 577 #ifndef PRODUCT
 578   if (VerifyStack) {
 579     ResourceMark res_mark;
 580 
 581     // Verify that the just-unpacked frames match the interpreter's
 582     // notions of expression stack and locals
 583     vframeArray* cur_array = thread->vframe_array_last();
 584     RegisterMap rm(thread, false);
 585     rm.set_include_argument_oops(false);
 586     bool is_top_frame = true;
 587     int callee_size_of_parameters = 0;
 588     int callee_max_locals = 0;
 589     for (int i = 0; i < cur_array->frames(); i++) {
 590       vframeArrayElement* el = cur_array->element(i);
 591       frame* iframe = el->iframe();
 592       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 593 
 594       // Get the oop map for this bci
 595       InterpreterOopMap mask;
 596       int cur_invoke_parameter_size = 0;
 597       bool try_next_mask = false;
 598       int next_mask_expression_stack_size = -1;
 599       int top_frame_expression_stack_adjustment = 0;
 600       methodHandle mh(thread, iframe->interpreter_frame_method());
 601       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 602       BytecodeStream str(mh);
 603       str.set_start(iframe->interpreter_frame_bci());
 604       int max_bci = mh->code_size();
 605       // Get to the next bytecode if possible
 606       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 607       // Check to see if we can grab the number of outgoing arguments
 608       // at an uncommon trap for an invoke (where the compiler
 609       // generates debug info before the invoke has executed)
 610       Bytecodes::Code cur_code = str.next();
 611       if (cur_code == Bytecodes::_invokevirtual ||
 612           cur_code == Bytecodes::_invokespecial ||
 613           cur_code == Bytecodes::_invokestatic  ||
 614           cur_code == Bytecodes::_invokeinterface) {
 615         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 616         Symbol* signature = invoke.signature();
 617         ArgumentSizeComputer asc(signature);
 618         cur_invoke_parameter_size = asc.size();
 619         if (cur_code != Bytecodes::_invokestatic) {
 620           // Add in receiver
 621           ++cur_invoke_parameter_size;
 622         }
 623       }
 624       if (str.bci() < max_bci) {
 625         Bytecodes::Code bc = str.next();
 626         if (bc >= 0) {
 627           // The interpreter oop map generator reports results before
 628           // the current bytecode has executed except in the case of
 629           // calls. It seems to be hard to tell whether the compiler
 630           // has emitted debug information matching the "state before"
 631           // a given bytecode or the state after, so we try both
 632           switch (cur_code) {
 633             case Bytecodes::_invokevirtual:
 634             case Bytecodes::_invokespecial:
 635             case Bytecodes::_invokestatic:
 636             case Bytecodes::_invokeinterface:
 637             case Bytecodes::_athrow:
 638               break;
 639             default: {
 640               InterpreterOopMap next_mask;
 641               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 642               next_mask_expression_stack_size = next_mask.expression_stack_size();
 643               // Need to subtract off the size of the result type of
 644               // the bytecode because this is not described in the
 645               // debug info but returned to the interpreter in the TOS
 646               // caching register
 647               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 648               if (bytecode_result_type != T_ILLEGAL) {
 649                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 650               }
 651               assert(top_frame_expression_stack_adjustment >= 0, "");
 652               try_next_mask = true;
 653               break;
 654             }
 655           }
 656         }
 657       }
 658 
 659       // Verify stack depth and oops in frame
 660       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 661       if (!(
 662             /* SPARC */
 663             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 664             /* x86 */
 665             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 666             (try_next_mask &&
 667              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 668                                                                     top_frame_expression_stack_adjustment))) ||
 669             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 670             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
 671              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 672             )) {
 673         ttyLocker ttyl;
 674 
 675         // Print out some information that will help us debug the problem
 676         tty->print_cr("Wrong number of expression stack elements during deoptimization");
 677         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 678         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 679                       iframe->interpreter_frame_expression_stack_size());
 680         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 681         tty->print_cr("  try_next_mask = %d", try_next_mask);
 682         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 683         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 684         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 685         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 686         tty->print_cr("  exec_mode = %d", exec_mode);
 687         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 688         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
 689         tty->print_cr("  Interpreted frames:");
 690         for (int k = 0; k < cur_array->frames(); k++) {
 691           vframeArrayElement* el = cur_array->element(k);
 692           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 693         }
 694         cur_array->print_on_2(tty);
 695         guarantee(false, "wrong number of expression stack elements during deopt");
 696       }
 697       VerifyOopClosure verify;
 698       iframe->oops_interpreted_do(&verify, &rm, false);
 699       callee_size_of_parameters = mh->size_of_parameters();
 700       callee_max_locals = mh->max_locals();
 701       is_top_frame = false;
 702     }
 703   }
 704 #endif /* !PRODUCT */
 705 
 706 
 707   return bt;
 708 JRT_END
 709 
 710 
 711 int Deoptimization::deoptimize_dependents() {
 712   Threads::deoptimized_wrt_marked_nmethods();
 713   return 0;
 714 }
 715 
 716 
 717 #ifdef COMPILER2
 718 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
 719   Handle pending_exception(thread->pending_exception());
 720   const char* exception_file = thread->exception_file();
 721   int exception_line = thread->exception_line();
 722   thread->clear_pending_exception();
 723 
 724   for (int i = 0; i < objects->length(); i++) {
 725     assert(objects->at(i)->is_object(), "invalid debug information");
 726     ObjectValue* sv = (ObjectValue*) objects->at(i);
 727 
 728     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
 729     oop obj = NULL;
 730 
 731     if (k->oop_is_instance()) {
 732       instanceKlass* ik = instanceKlass::cast(k());
 733       obj = ik->allocate_instance(CHECK_(false));
 734     } else if (k->oop_is_typeArray()) {
 735       typeArrayKlass* ak = typeArrayKlass::cast(k());
 736       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
 737       int len = sv->field_size() / type2size[ak->element_type()];
 738       obj = ak->allocate(len, CHECK_(false));
 739     } else if (k->oop_is_objArray()) {
 740       objArrayKlass* ak = objArrayKlass::cast(k());
 741       obj = ak->allocate(sv->field_size(), CHECK_(false));
 742     }
 743 
 744     assert(obj != NULL, "allocation failed");
 745     assert(sv->value().is_null(), "redundant reallocation");
 746     sv->set_value(obj);
 747   }
 748 
 749   if (pending_exception.not_null()) {
 750     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
 751   }
 752 
 753   return true;
 754 }
 755 
 756 // This assumes that the fields are stored in ObjectValue in the same order
 757 // they are yielded by do_nonstatic_fields.
 758 class FieldReassigner: public FieldClosure {
 759   frame* _fr;
 760   RegisterMap* _reg_map;
 761   ObjectValue* _sv;
 762   instanceKlass* _ik;
 763   oop _obj;
 764 
 765   int _i;
 766 public:
 767   FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
 768     _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
 769 
 770   int i() const { return _i; }
 771 
 772 
 773   void do_field(fieldDescriptor* fd) {
 774     intptr_t val;
 775     StackValue* value =
 776       StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
 777     int offset = fd->offset();
 778     switch (fd->field_type()) {
 779     case T_OBJECT: case T_ARRAY:
 780       assert(value->type() == T_OBJECT, "Agreement.");
 781       _obj->obj_field_put(offset, value->get_obj()());
 782       break;
 783 
 784     case T_LONG: case T_DOUBLE: {
 785       assert(value->type() == T_INT, "Agreement.");
 786       StackValue* low =
 787         StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
 788 #ifdef _LP64
 789       jlong res = (jlong)low->get_int();
 790 #else
 791 #ifdef SPARC
 792       // For SPARC we have to swap high and low words.
 793       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 794 #else
 795       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 796 #endif //SPARC
 797 #endif
 798       _obj->long_field_put(offset, res);
 799       break;
 800     }
 801     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 802     case T_INT: case T_FLOAT: // 4 bytes.
 803       assert(value->type() == T_INT, "Agreement.");
 804       val = value->get_int();
 805       _obj->int_field_put(offset, (jint)*((jint*)&val));
 806       break;
 807 
 808     case T_SHORT: case T_CHAR: // 2 bytes
 809       assert(value->type() == T_INT, "Agreement.");
 810       val = value->get_int();
 811       _obj->short_field_put(offset, (jshort)*((jint*)&val));
 812       break;
 813 
 814     case T_BOOLEAN: case T_BYTE: // 1 byte
 815       assert(value->type() == T_INT, "Agreement.");
 816       val = value->get_int();
 817       _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
 818       break;
 819 
 820     default:
 821       ShouldNotReachHere();
 822     }
 823     _i++;
 824   }
 825 };
 826 
 827 // restore elements of an eliminated type array
 828 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
 829   int index = 0;
 830   intptr_t val;
 831 
 832   for (int i = 0; i < sv->field_size(); i++) {
 833     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 834     switch(type) {
 835     case T_LONG: case T_DOUBLE: {
 836       assert(value->type() == T_INT, "Agreement.");
 837       StackValue* low =
 838         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 839 #ifdef _LP64
 840       jlong res = (jlong)low->get_int();
 841 #else
 842 #ifdef SPARC
 843       // For SPARC we have to swap high and low words.
 844       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 845 #else
 846       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 847 #endif //SPARC
 848 #endif
 849       obj->long_at_put(index, res);
 850       break;
 851     }
 852 
 853     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 854     case T_INT: case T_FLOAT: // 4 bytes.
 855       assert(value->type() == T_INT, "Agreement.");
 856       val = value->get_int();
 857       obj->int_at_put(index, (jint)*((jint*)&val));
 858       break;
 859 
 860     case T_SHORT: case T_CHAR: // 2 bytes
 861       assert(value->type() == T_INT, "Agreement.");
 862       val = value->get_int();
 863       obj->short_at_put(index, (jshort)*((jint*)&val));
 864       break;
 865 
 866     case T_BOOLEAN: case T_BYTE: // 1 byte
 867       assert(value->type() == T_INT, "Agreement.");
 868       val = value->get_int();
 869       obj->bool_at_put(index, (jboolean)*((jint*)&val));
 870       break;
 871 
 872       default:
 873         ShouldNotReachHere();
 874     }
 875     index++;
 876   }
 877 }
 878 
 879 
 880 // restore fields of an eliminated object array
 881 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
 882   for (int i = 0; i < sv->field_size(); i++) {
 883     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 884     assert(value->type() == T_OBJECT, "object element expected");
 885     obj->obj_at_put(i, value->get_obj()());
 886   }
 887 }
 888 
 889 
 890 // restore fields of all eliminated objects and arrays
 891 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
 892   for (int i = 0; i < objects->length(); i++) {
 893     ObjectValue* sv = (ObjectValue*) objects->at(i);
 894     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
 895     Handle obj = sv->value();
 896     assert(obj.not_null(), "reallocation was missed");
 897 
 898     if (k->oop_is_instance()) {
 899       instanceKlass* ik = instanceKlass::cast(k());
 900       FieldReassigner reassign(fr, reg_map, sv, obj());
 901       ik->do_nonstatic_fields(&reassign);
 902     } else if (k->oop_is_typeArray()) {
 903       typeArrayKlass* ak = typeArrayKlass::cast(k());
 904       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
 905     } else if (k->oop_is_objArray()) {
 906       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
 907     }
 908   }
 909 }
 910 
 911 
 912 // relock objects for which synchronization was eliminated
 913 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
 914   for (int i = 0; i < monitors->length(); i++) {
 915     MonitorInfo* mon_info = monitors->at(i);
 916     if (mon_info->eliminated()) {
 917       assert(mon_info->owner() != NULL, "reallocation was missed");
 918       Handle obj = Handle(mon_info->owner());
 919       markOop mark = obj->mark();
 920       if (UseBiasedLocking && mark->has_bias_pattern()) {
 921         // New allocated objects may have the mark set to anonymously biased.
 922         // Also the deoptimized method may called methods with synchronization
 923         // where the thread-local object is bias locked to the current thread.
 924         assert(mark->is_biased_anonymously() ||
 925                mark->biased_locker() == thread, "should be locked to current thread");
 926         // Reset mark word to unbiased prototype.
 927         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
 928         obj->set_mark(unbiased_prototype);
 929       }
 930       BasicLock* lock = mon_info->lock();
 931       ObjectSynchronizer::slow_enter(obj, lock, thread);
 932     }
 933     assert(mon_info->owner()->is_locked(), "object must be locked now");
 934   }
 935 }
 936 
 937 
 938 #ifndef PRODUCT
 939 // print information about reallocated objects
 940 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
 941   fieldDescriptor fd;
 942 
 943   for (int i = 0; i < objects->length(); i++) {
 944     ObjectValue* sv = (ObjectValue*) objects->at(i);
 945     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
 946     Handle obj = sv->value();
 947 
 948     tty->print("     object <" INTPTR_FORMAT "> of type ", sv->value()());
 949     k->as_klassOop()->print_value();
 950     tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
 951     tty->cr();
 952 
 953     if (Verbose) {
 954       k->oop_print_on(obj(), tty);
 955     }
 956   }
 957 }
 958 #endif
 959 #endif // COMPILER2
 960 
 961 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
 962 
 963 #ifndef PRODUCT
 964   if (TraceDeoptimization) {
 965     ttyLocker ttyl;
 966     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
 967     fr.print_on(tty);
 968     tty->print_cr("     Virtual frames (innermost first):");
 969     for (int index = 0; index < chunk->length(); index++) {
 970       compiledVFrame* vf = chunk->at(index);
 971       tty->print("       %2d - ", index);
 972       vf->print_value();
 973       int bci = chunk->at(index)->raw_bci();
 974       const char* code_name;
 975       if (bci == SynchronizationEntryBCI) {
 976         code_name = "sync entry";
 977       } else {
 978         Bytecodes::Code code = vf->method()->code_at(bci);
 979         code_name = Bytecodes::name(code);
 980       }
 981       tty->print(" - %s", code_name);
 982       tty->print_cr(" @ bci %d ", bci);
 983       if (Verbose) {
 984         vf->print();
 985         tty->cr();
 986       }
 987     }
 988   }
 989 #endif
 990 
 991   // Register map for next frame (used for stack crawl).  We capture
 992   // the state of the deopt'ing frame's caller.  Thus if we need to
 993   // stuff a C2I adapter we can properly fill in the callee-save
 994   // register locations.
 995   frame caller = fr.sender(reg_map);
 996   int frame_size = caller.sp() - fr.sp();
 997 
 998   frame sender = caller;
 999 
1000   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1001   // the vframeArray containing the unpacking information is allocated in the C heap.
1002   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1003   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1004 
1005   // Compare the vframeArray to the collected vframes
1006   assert(array->structural_compare(thread, chunk), "just checking");
1007   Events::log("# vframes = %d", (intptr_t)chunk->length());
1008 
1009 #ifndef PRODUCT
1010   if (TraceDeoptimization) {
1011     ttyLocker ttyl;
1012     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, array);
1013   }
1014 #endif // PRODUCT
1015 
1016   return array;
1017 }
1018 
1019 
1020 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1021   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1022   for (int i = 0; i < monitors->length(); i++) {
1023     MonitorInfo* mon_info = monitors->at(i);
1024     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1025       objects_to_revoke->append(Handle(mon_info->owner()));
1026     }
1027   }
1028 }
1029 
1030 
1031 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1032   if (!UseBiasedLocking) {
1033     return;
1034   }
1035 
1036   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1037 
1038   // Unfortunately we don't have a RegisterMap available in most of
1039   // the places we want to call this routine so we need to walk the
1040   // stack again to update the register map.
1041   if (map == NULL || !map->update_map()) {
1042     StackFrameStream sfs(thread, true);
1043     bool found = false;
1044     while (!found && !sfs.is_done()) {
1045       frame* cur = sfs.current();
1046       sfs.next();
1047       found = cur->id() == fr.id();
1048     }
1049     assert(found, "frame to be deoptimized not found on target thread's stack");
1050     map = sfs.register_map();
1051   }
1052 
1053   vframe* vf = vframe::new_vframe(&fr, map, thread);
1054   compiledVFrame* cvf = compiledVFrame::cast(vf);
1055   // Revoke monitors' biases in all scopes
1056   while (!cvf->is_top()) {
1057     collect_monitors(cvf, objects_to_revoke);
1058     cvf = compiledVFrame::cast(cvf->sender());
1059   }
1060   collect_monitors(cvf, objects_to_revoke);
1061 
1062   if (SafepointSynchronize::is_at_safepoint()) {
1063     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1064   } else {
1065     BiasedLocking::revoke(objects_to_revoke);
1066   }
1067 }
1068 
1069 
1070 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1071   if (!UseBiasedLocking) {
1072     return;
1073   }
1074 
1075   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1076   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1077   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1078     if (jt->has_last_Java_frame()) {
1079       StackFrameStream sfs(jt, true);
1080       while (!sfs.is_done()) {
1081         frame* cur = sfs.current();
1082         if (cb->contains(cur->pc())) {
1083           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1084           compiledVFrame* cvf = compiledVFrame::cast(vf);
1085           // Revoke monitors' biases in all scopes
1086           while (!cvf->is_top()) {
1087             collect_monitors(cvf, objects_to_revoke);
1088             cvf = compiledVFrame::cast(cvf->sender());
1089           }
1090           collect_monitors(cvf, objects_to_revoke);
1091         }
1092         sfs.next();
1093       }
1094     }
1095   }
1096   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1097 }
1098 
1099 
1100 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1101   assert(fr.can_be_deoptimized(), "checking frame type");
1102 
1103   gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1104 
1105   EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
1106 
1107   // Patch the nmethod so that when execution returns to it we will
1108   // deopt the execution state and return to the interpreter.
1109   fr.deoptimize(thread);
1110 }
1111 
1112 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1113   // Deoptimize only if the frame comes from compile code.
1114   // Do not deoptimize the frame which is already patched
1115   // during the execution of the loops below.
1116   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1117     return;
1118   }
1119   ResourceMark rm;
1120   DeoptimizationMarker dm;
1121   if (UseBiasedLocking) {
1122     revoke_biases_of_monitors(thread, fr, map);
1123   }
1124   deoptimize_single_frame(thread, fr);
1125 
1126 }
1127 
1128 
1129 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1130   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1131          "can only deoptimize other thread at a safepoint");
1132   // Compute frame and register map based on thread and sp.
1133   RegisterMap reg_map(thread, UseBiasedLocking);
1134   frame fr = thread->last_frame();
1135   while (fr.id() != id) {
1136     fr = fr.sender(&reg_map);
1137   }
1138   deoptimize(thread, fr, &reg_map);
1139 }
1140 
1141 
1142 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1143   if (thread == Thread::current()) {
1144     Deoptimization::deoptimize_frame_internal(thread, id);
1145   } else {
1146     VM_DeoptimizeFrame deopt(thread, id);
1147     VMThread::execute(&deopt);
1148   }
1149 }
1150 
1151 
1152 // JVMTI PopFrame support
1153 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1154 {
1155   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1156 }
1157 JRT_END
1158 
1159 
1160 #if defined(COMPILER2) || defined(SHARK)
1161 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1162   // in case of an unresolved klass entry, load the class.
1163   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1164     klassOop tk = constant_pool->klass_at(index, CHECK);
1165     return;
1166   }
1167 
1168   if (!constant_pool->tag_at(index).is_symbol()) return;
1169 
1170   Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
1171   Symbol*  symbol  = constant_pool->symbol_at(index);
1172 
1173   // class name?
1174   if (symbol->byte_at(0) != '(') {
1175     Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1176     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1177     return;
1178   }
1179 
1180   // then it must be a signature!
1181   ResourceMark rm(THREAD);
1182   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1183     if (ss.is_object()) {
1184       Symbol* class_name = ss.as_symbol(CHECK);
1185       Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
1186       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1187     }
1188   }
1189 }
1190 
1191 
1192 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1193   EXCEPTION_MARK;
1194   load_class_by_index(constant_pool, index, THREAD);
1195   if (HAS_PENDING_EXCEPTION) {
1196     // Exception happened during classloading. We ignore the exception here, since it
1197     // is going to be rethrown since the current activation is going to be deoptimzied and
1198     // the interpreter will re-execute the bytecode.
1199     CLEAR_PENDING_EXCEPTION;
1200   }
1201 }
1202 
1203 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1204   HandleMark hm;
1205 
1206   // uncommon_trap() is called at the beginning of the uncommon trap
1207   // handler. Note this fact before we start generating temporary frames
1208   // that can confuse an asynchronous stack walker. This counter is
1209   // decremented at the end of unpack_frames().
1210   thread->inc_in_deopt_handler();
1211 
1212   // We need to update the map if we have biased locking.
1213   RegisterMap reg_map(thread, UseBiasedLocking);
1214   frame stub_frame = thread->last_frame();
1215   frame fr = stub_frame.sender(&reg_map);
1216   // Make sure the calling nmethod is not getting deoptimized and removed
1217   // before we are done with it.
1218   nmethodLocker nl(fr.pc());
1219 
1220   {
1221     ResourceMark rm;
1222 
1223     // Revoke biases of any monitors in the frame to ensure we can migrate them
1224     revoke_biases_of_monitors(thread, fr, &reg_map);
1225 
1226     DeoptReason reason = trap_request_reason(trap_request);
1227     DeoptAction action = trap_request_action(trap_request);
1228     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1229 
1230     Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
1231     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
1232     compiledVFrame* cvf = compiledVFrame::cast(vf);
1233 
1234     nmethod* nm = cvf->code();
1235 
1236     ScopeDesc*      trap_scope  = cvf->scope();
1237     methodHandle    trap_method = trap_scope->method();
1238     int             trap_bci    = trap_scope->bci();
1239     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
1240 
1241     // Record this event in the histogram.
1242     gather_statistics(reason, action, trap_bc);
1243 
1244     // Ensure that we can record deopt. history:
1245     bool create_if_missing = ProfileTraps;
1246 
1247     methodDataHandle trap_mdo
1248       (THREAD, get_method_data(thread, trap_method, create_if_missing));
1249 
1250     // Print a bunch of diagnostics, if requested.
1251     if (TraceDeoptimization || LogCompilation) {
1252       ResourceMark rm;
1253       ttyLocker ttyl;
1254       char buf[100];
1255       if (xtty != NULL) {
1256         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1257                          os::current_thread_id(),
1258                          format_trap_request(buf, sizeof(buf), trap_request));
1259         nm->log_identity(xtty);
1260       }
1261       Symbol* class_name = NULL;
1262       bool unresolved = false;
1263       if (unloaded_class_index >= 0) {
1264         constantPoolHandle constants (THREAD, trap_method->constants());
1265         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1266           class_name = constants->klass_name_at(unloaded_class_index);
1267           unresolved = true;
1268           if (xtty != NULL)
1269             xtty->print(" unresolved='1'");
1270         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1271           class_name = constants->symbol_at(unloaded_class_index);
1272         }
1273         if (xtty != NULL)
1274           xtty->name(class_name);
1275       }
1276       if (xtty != NULL && trap_mdo.not_null()) {
1277         // Dump the relevant MDO state.
1278         // This is the deopt count for the current reason, any previous
1279         // reasons or recompiles seen at this point.
1280         int dcnt = trap_mdo->trap_count(reason);
1281         if (dcnt != 0)
1282           xtty->print(" count='%d'", dcnt);
1283         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1284         int dos = (pdata == NULL)? 0: pdata->trap_state();
1285         if (dos != 0) {
1286           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1287           if (trap_state_is_recompiled(dos)) {
1288             int recnt2 = trap_mdo->overflow_recompile_count();
1289             if (recnt2 != 0)
1290               xtty->print(" recompiles2='%d'", recnt2);
1291           }
1292         }
1293       }
1294       if (xtty != NULL) {
1295         xtty->stamp();
1296         xtty->end_head();
1297       }
1298       if (TraceDeoptimization) {  // make noise on the tty
1299         tty->print("Uncommon trap occurred in");
1300         nm->method()->print_short_name(tty);
1301         tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
1302                    fr.pc(),
1303                    (int) os::current_thread_id(),
1304                    trap_reason_name(reason),
1305                    trap_action_name(action),
1306                    unloaded_class_index);
1307         if (class_name != NULL) {
1308           tty->print(unresolved ? " unresolved class: " : " symbol: ");
1309           class_name->print_symbol_on(tty);
1310         }
1311         tty->cr();
1312       }
1313       if (xtty != NULL) {
1314         // Log the precise location of the trap.
1315         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1316           xtty->begin_elem("jvms bci='%d'", sd->bci());
1317           xtty->method(sd->method());
1318           xtty->end_elem();
1319           if (sd->is_top())  break;
1320         }
1321         xtty->tail("uncommon_trap");
1322       }
1323     }
1324     // (End diagnostic printout.)
1325 
1326     // Load class if necessary
1327     if (unloaded_class_index >= 0) {
1328       constantPoolHandle constants(THREAD, trap_method->constants());
1329       load_class_by_index(constants, unloaded_class_index);
1330     }
1331 
1332     // Flush the nmethod if necessary and desirable.
1333     //
1334     // We need to avoid situations where we are re-flushing the nmethod
1335     // because of a hot deoptimization site.  Repeated flushes at the same
1336     // point need to be detected by the compiler and avoided.  If the compiler
1337     // cannot avoid them (or has a bug and "refuses" to avoid them), this
1338     // module must take measures to avoid an infinite cycle of recompilation
1339     // and deoptimization.  There are several such measures:
1340     //
1341     //   1. If a recompilation is ordered a second time at some site X
1342     //   and for the same reason R, the action is adjusted to 'reinterpret',
1343     //   to give the interpreter time to exercise the method more thoroughly.
1344     //   If this happens, the method's overflow_recompile_count is incremented.
1345     //
1346     //   2. If the compiler fails to reduce the deoptimization rate, then
1347     //   the method's overflow_recompile_count will begin to exceed the set
1348     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
1349     //   is adjusted to 'make_not_compilable', and the method is abandoned
1350     //   to the interpreter.  This is a performance hit for hot methods,
1351     //   but is better than a disastrous infinite cycle of recompilations.
1352     //   (Actually, only the method containing the site X is abandoned.)
1353     //
1354     //   3. In parallel with the previous measures, if the total number of
1355     //   recompilations of a method exceeds the much larger set limit
1356     //   PerMethodRecompilationCutoff, the method is abandoned.
1357     //   This should only happen if the method is very large and has
1358     //   many "lukewarm" deoptimizations.  The code which enforces this
1359     //   limit is elsewhere (class nmethod, class methodOopDesc).
1360     //
1361     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1362     // to recompile at each bytecode independently of the per-BCI cutoff.
1363     //
1364     // The decision to update code is up to the compiler, and is encoded
1365     // in the Action_xxx code.  If the compiler requests Action_none
1366     // no trap state is changed, no compiled code is changed, and the
1367     // computation suffers along in the interpreter.
1368     //
1369     // The other action codes specify various tactics for decompilation
1370     // and recompilation.  Action_maybe_recompile is the loosest, and
1371     // allows the compiled code to stay around until enough traps are seen,
1372     // and until the compiler gets around to recompiling the trapping method.
1373     //
1374     // The other actions cause immediate removal of the present code.
1375 
1376     bool update_trap_state = true;
1377     bool make_not_entrant = false;
1378     bool make_not_compilable = false;
1379     bool reprofile = false;
1380     switch (action) {
1381     case Action_none:
1382       // Keep the old code.
1383       update_trap_state = false;
1384       break;
1385     case Action_maybe_recompile:
1386       // Do not need to invalidate the present code, but we can
1387       // initiate another
1388       // Start compiler without (necessarily) invalidating the nmethod.
1389       // The system will tolerate the old code, but new code should be
1390       // generated when possible.
1391       break;
1392     case Action_reinterpret:
1393       // Go back into the interpreter for a while, and then consider
1394       // recompiling form scratch.
1395       make_not_entrant = true;
1396       // Reset invocation counter for outer most method.
1397       // This will allow the interpreter to exercise the bytecodes
1398       // for a while before recompiling.
1399       // By contrast, Action_make_not_entrant is immediate.
1400       //
1401       // Note that the compiler will track null_check, null_assert,
1402       // range_check, and class_check events and log them as if they
1403       // had been traps taken from compiled code.  This will update
1404       // the MDO trap history so that the next compilation will
1405       // properly detect hot trap sites.
1406       reprofile = true;
1407       break;
1408     case Action_make_not_entrant:
1409       // Request immediate recompilation, and get rid of the old code.
1410       // Make them not entrant, so next time they are called they get
1411       // recompiled.  Unloaded classes are loaded now so recompile before next
1412       // time they are called.  Same for uninitialized.  The interpreter will
1413       // link the missing class, if any.
1414       make_not_entrant = true;
1415       break;
1416     case Action_make_not_compilable:
1417       // Give up on compiling this method at all.
1418       make_not_entrant = true;
1419       make_not_compilable = true;
1420       break;
1421     default:
1422       ShouldNotReachHere();
1423     }
1424 
1425     // Setting +ProfileTraps fixes the following, on all platforms:
1426     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
1427     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1428     // recompile relies on a methodDataOop to record heroic opt failures.
1429 
1430     // Whether the interpreter is producing MDO data or not, we also need
1431     // to use the MDO to detect hot deoptimization points and control
1432     // aggressive optimization.
1433     bool inc_recompile_count = false;
1434     ProfileData* pdata = NULL;
1435     if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
1436       assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
1437       uint this_trap_count = 0;
1438       bool maybe_prior_trap = false;
1439       bool maybe_prior_recompile = false;
1440       pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1441                                    //outputs:
1442                                    this_trap_count,
1443                                    maybe_prior_trap,
1444                                    maybe_prior_recompile);
1445       // Because the interpreter also counts null, div0, range, and class
1446       // checks, these traps from compiled code are double-counted.
1447       // This is harmless; it just means that the PerXTrapLimit values
1448       // are in effect a little smaller than they look.
1449 
1450       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1451       if (per_bc_reason != Reason_none) {
1452         // Now take action based on the partially known per-BCI history.
1453         if (maybe_prior_trap
1454             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1455           // If there are too many traps at this BCI, force a recompile.
1456           // This will allow the compiler to see the limit overflow, and
1457           // take corrective action, if possible.  The compiler generally
1458           // does not use the exact PerBytecodeTrapLimit value, but instead
1459           // changes its tactics if it sees any traps at all.  This provides
1460           // a little hysteresis, delaying a recompile until a trap happens
1461           // several times.
1462           //
1463           // Actually, since there is only one bit of counter per BCI,
1464           // the possible per-BCI counts are {0,1,(per-method count)}.
1465           // This produces accurate results if in fact there is only
1466           // one hot trap site, but begins to get fuzzy if there are
1467           // many sites.  For example, if there are ten sites each
1468           // trapping two or more times, they each get the blame for
1469           // all of their traps.
1470           make_not_entrant = true;
1471         }
1472 
1473         // Detect repeated recompilation at the same BCI, and enforce a limit.
1474         if (make_not_entrant && maybe_prior_recompile) {
1475           // More than one recompile at this point.
1476           inc_recompile_count = maybe_prior_trap;
1477         }
1478       } else {
1479         // For reasons which are not recorded per-bytecode, we simply
1480         // force recompiles unconditionally.
1481         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1482         make_not_entrant = true;
1483       }
1484 
1485       // Go back to the compiler if there are too many traps in this method.
1486       if (this_trap_count >= (uint)PerMethodTrapLimit) {
1487         // If there are too many traps in this method, force a recompile.
1488         // This will allow the compiler to see the limit overflow, and
1489         // take corrective action, if possible.
1490         // (This condition is an unlikely backstop only, because the
1491         // PerBytecodeTrapLimit is more likely to take effect first,
1492         // if it is applicable.)
1493         make_not_entrant = true;
1494       }
1495 
1496       // Here's more hysteresis:  If there has been a recompile at
1497       // this trap point already, run the method in the interpreter
1498       // for a while to exercise it more thoroughly.
1499       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1500         reprofile = true;
1501       }
1502 
1503     }
1504 
1505     // Take requested actions on the method:
1506 
1507     // Recompile
1508     if (make_not_entrant) {
1509       if (!nm->make_not_entrant()) {
1510         return; // the call did not change nmethod's state
1511       }
1512 
1513       if (pdata != NULL) {
1514         // Record the recompilation event, if any.
1515         int tstate0 = pdata->trap_state();
1516         int tstate1 = trap_state_set_recompiled(tstate0, true);
1517         if (tstate1 != tstate0)
1518           pdata->set_trap_state(tstate1);
1519       }
1520     }
1521 
1522     if (inc_recompile_count) {
1523       trap_mdo->inc_overflow_recompile_count();
1524       if ((uint)trap_mdo->overflow_recompile_count() >
1525           (uint)PerBytecodeRecompilationCutoff) {
1526         // Give up on the method containing the bad BCI.
1527         if (trap_method() == nm->method()) {
1528           make_not_compilable = true;
1529         } else {
1530           trap_method->set_not_compilable(CompLevel_full_optimization);
1531           // But give grace to the enclosing nm->method().
1532         }
1533       }
1534     }
1535 
1536     // Reprofile
1537     if (reprofile) {
1538       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1539     }
1540 
1541     // Give up compiling
1542     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1543       assert(make_not_entrant, "consistent");
1544       nm->method()->set_not_compilable(CompLevel_full_optimization);
1545     }
1546 
1547   } // Free marked resources
1548 
1549 }
1550 JRT_END
1551 
1552 methodDataOop
1553 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1554                                 bool create_if_missing) {
1555   Thread* THREAD = thread;
1556   methodDataOop mdo = m()->method_data();
1557   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1558     // Build an MDO.  Ignore errors like OutOfMemory;
1559     // that simply means we won't have an MDO to update.
1560     methodOopDesc::build_interpreter_method_data(m, THREAD);
1561     if (HAS_PENDING_EXCEPTION) {
1562       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1563       CLEAR_PENDING_EXCEPTION;
1564     }
1565     mdo = m()->method_data();
1566   }
1567   return mdo;
1568 }
1569 
1570 ProfileData*
1571 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
1572                                          int trap_bci,
1573                                          Deoptimization::DeoptReason reason,
1574                                          //outputs:
1575                                          uint& ret_this_trap_count,
1576                                          bool& ret_maybe_prior_trap,
1577                                          bool& ret_maybe_prior_recompile) {
1578   uint prior_trap_count = trap_mdo->trap_count(reason);
1579   uint this_trap_count  = trap_mdo->inc_trap_count(reason);
1580 
1581   // If the runtime cannot find a place to store trap history,
1582   // it is estimated based on the general condition of the method.
1583   // If the method has ever been recompiled, or has ever incurred
1584   // a trap with the present reason , then this BCI is assumed
1585   // (pessimistically) to be the culprit.
1586   bool maybe_prior_trap      = (prior_trap_count != 0);
1587   bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1588   ProfileData* pdata = NULL;
1589 
1590 
1591   // For reasons which are recorded per bytecode, we check per-BCI data.
1592   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1593   if (per_bc_reason != Reason_none) {
1594     // Find the profile data for this BCI.  If there isn't one,
1595     // try to allocate one from the MDO's set of spares.
1596     // This will let us detect a repeated trap at this point.
1597     pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1598 
1599     if (pdata != NULL) {
1600       // Query the trap state of this profile datum.
1601       int tstate0 = pdata->trap_state();
1602       if (!trap_state_has_reason(tstate0, per_bc_reason))
1603         maybe_prior_trap = false;
1604       if (!trap_state_is_recompiled(tstate0))
1605         maybe_prior_recompile = false;
1606 
1607       // Update the trap state of this profile datum.
1608       int tstate1 = tstate0;
1609       // Record the reason.
1610       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1611       // Store the updated state on the MDO, for next time.
1612       if (tstate1 != tstate0)
1613         pdata->set_trap_state(tstate1);
1614     } else {
1615       if (LogCompilation && xtty != NULL) {
1616         ttyLocker ttyl;
1617         // Missing MDP?  Leave a small complaint in the log.
1618         xtty->elem("missing_mdp bci='%d'", trap_bci);
1619       }
1620     }
1621   }
1622 
1623   // Return results:
1624   ret_this_trap_count = this_trap_count;
1625   ret_maybe_prior_trap = maybe_prior_trap;
1626   ret_maybe_prior_recompile = maybe_prior_recompile;
1627   return pdata;
1628 }
1629 
1630 void
1631 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1632   ResourceMark rm;
1633   // Ignored outputs:
1634   uint ignore_this_trap_count;
1635   bool ignore_maybe_prior_trap;
1636   bool ignore_maybe_prior_recompile;
1637   query_update_method_data(trap_mdo, trap_bci,
1638                            (DeoptReason)reason,
1639                            ignore_this_trap_count,
1640                            ignore_maybe_prior_trap,
1641                            ignore_maybe_prior_recompile);
1642 }
1643 
1644 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1645 
1646   // Still in Java no safepoints
1647   {
1648     // This enters VM and may safepoint
1649     uncommon_trap_inner(thread, trap_request);
1650   }
1651   return fetch_unroll_info_helper(thread);
1652 }
1653 
1654 // Local derived constants.
1655 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1656 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
1657 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1658 
1659 //---------------------------trap_state_reason---------------------------------
1660 Deoptimization::DeoptReason
1661 Deoptimization::trap_state_reason(int trap_state) {
1662   // This assert provides the link between the width of DataLayout::trap_bits
1663   // and the encoding of "recorded" reasons.  It ensures there are enough
1664   // bits to store all needed reasons in the per-BCI MDO profile.
1665   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1666   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1667   trap_state -= recompile_bit;
1668   if (trap_state == DS_REASON_MASK) {
1669     return Reason_many;
1670   } else {
1671     assert((int)Reason_none == 0, "state=0 => Reason_none");
1672     return (DeoptReason)trap_state;
1673   }
1674 }
1675 //-------------------------trap_state_has_reason-------------------------------
1676 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1677   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1678   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1679   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1680   trap_state -= recompile_bit;
1681   if (trap_state == DS_REASON_MASK) {
1682     return -1;  // true, unspecifically (bottom of state lattice)
1683   } else if (trap_state == reason) {
1684     return 1;   // true, definitely
1685   } else if (trap_state == 0) {
1686     return 0;   // false, definitely (top of state lattice)
1687   } else {
1688     return 0;   // false, definitely
1689   }
1690 }
1691 //-------------------------trap_state_add_reason-------------------------------
1692 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1693   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1694   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1695   trap_state -= recompile_bit;
1696   if (trap_state == DS_REASON_MASK) {
1697     return trap_state + recompile_bit;     // already at state lattice bottom
1698   } else if (trap_state == reason) {
1699     return trap_state + recompile_bit;     // the condition is already true
1700   } else if (trap_state == 0) {
1701     return reason + recompile_bit;          // no condition has yet been true
1702   } else {
1703     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
1704   }
1705 }
1706 //-----------------------trap_state_is_recompiled------------------------------
1707 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1708   return (trap_state & DS_RECOMPILE_BIT) != 0;
1709 }
1710 //-----------------------trap_state_set_recompiled-----------------------------
1711 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1712   if (z)  return trap_state |  DS_RECOMPILE_BIT;
1713   else    return trap_state & ~DS_RECOMPILE_BIT;
1714 }
1715 //---------------------------format_trap_state---------------------------------
1716 // This is used for debugging and diagnostics, including hotspot.log output.
1717 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1718                                               int trap_state) {
1719   DeoptReason reason      = trap_state_reason(trap_state);
1720   bool        recomp_flag = trap_state_is_recompiled(trap_state);
1721   // Re-encode the state from its decoded components.
1722   int decoded_state = 0;
1723   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1724     decoded_state = trap_state_add_reason(decoded_state, reason);
1725   if (recomp_flag)
1726     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1727   // If the state re-encodes properly, format it symbolically.
1728   // Because this routine is used for debugging and diagnostics,
1729   // be robust even if the state is a strange value.
1730   size_t len;
1731   if (decoded_state != trap_state) {
1732     // Random buggy state that doesn't decode??
1733     len = jio_snprintf(buf, buflen, "#%d", trap_state);
1734   } else {
1735     len = jio_snprintf(buf, buflen, "%s%s",
1736                        trap_reason_name(reason),
1737                        recomp_flag ? " recompiled" : "");
1738   }
1739   if (len >= buflen)
1740     buf[buflen-1] = '\0';
1741   return buf;
1742 }
1743 
1744 
1745 //--------------------------------statics--------------------------------------
1746 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1747   = Deoptimization::Action_reinterpret;
1748 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1749   // Note:  Keep this in sync. with enum DeoptReason.
1750   "none",
1751   "null_check",
1752   "null_assert",
1753   "range_check",
1754   "class_check",
1755   "array_check",
1756   "intrinsic",
1757   "bimorphic",
1758   "unloaded",
1759   "uninitialized",
1760   "unreached",
1761   "unhandled",
1762   "constraint",
1763   "div0_check",
1764   "age",
1765   "predicate"
1766 };
1767 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1768   // Note:  Keep this in sync. with enum DeoptAction.
1769   "none",
1770   "maybe_recompile",
1771   "reinterpret",
1772   "make_not_entrant",
1773   "make_not_compilable"
1774 };
1775 
1776 const char* Deoptimization::trap_reason_name(int reason) {
1777   if (reason == Reason_many)  return "many";
1778   if ((uint)reason < Reason_LIMIT)
1779     return _trap_reason_name[reason];
1780   static char buf[20];
1781   sprintf(buf, "reason%d", reason);
1782   return buf;
1783 }
1784 const char* Deoptimization::trap_action_name(int action) {
1785   if ((uint)action < Action_LIMIT)
1786     return _trap_action_name[action];
1787   static char buf[20];
1788   sprintf(buf, "action%d", action);
1789   return buf;
1790 }
1791 
1792 // This is used for debugging and diagnostics, including hotspot.log output.
1793 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1794                                                 int trap_request) {
1795   jint unloaded_class_index = trap_request_index(trap_request);
1796   const char* reason = trap_reason_name(trap_request_reason(trap_request));
1797   const char* action = trap_action_name(trap_request_action(trap_request));
1798   size_t len;
1799   if (unloaded_class_index < 0) {
1800     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1801                        reason, action);
1802   } else {
1803     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1804                        reason, action, unloaded_class_index);
1805   }
1806   if (len >= buflen)
1807     buf[buflen-1] = '\0';
1808   return buf;
1809 }
1810 
1811 juint Deoptimization::_deoptimization_hist
1812         [Deoptimization::Reason_LIMIT]
1813     [1 + Deoptimization::Action_LIMIT]
1814         [Deoptimization::BC_CASE_LIMIT]
1815   = {0};
1816 
1817 enum {
1818   LSB_BITS = 8,
1819   LSB_MASK = right_n_bits(LSB_BITS)
1820 };
1821 
1822 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1823                                        Bytecodes::Code bc) {
1824   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1825   assert(action >= 0 && action < Action_LIMIT, "oob");
1826   _deoptimization_hist[Reason_none][0][0] += 1;  // total
1827   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
1828   juint* cases = _deoptimization_hist[reason][1+action];
1829   juint* bc_counter_addr = NULL;
1830   juint  bc_counter      = 0;
1831   // Look for an unused counter, or an exact match to this BC.
1832   if (bc != Bytecodes::_illegal) {
1833     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1834       juint* counter_addr = &cases[bc_case];
1835       juint  counter = *counter_addr;
1836       if ((counter == 0 && bc_counter_addr == NULL)
1837           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1838         // this counter is either free or is already devoted to this BC
1839         bc_counter_addr = counter_addr;
1840         bc_counter = counter | bc;
1841       }
1842     }
1843   }
1844   if (bc_counter_addr == NULL) {
1845     // Overflow, or no given bytecode.
1846     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1847     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
1848   }
1849   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1850 }
1851 
1852 jint Deoptimization::total_deoptimization_count() {
1853   return _deoptimization_hist[Reason_none][0][0];
1854 }
1855 
1856 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1857   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1858   return _deoptimization_hist[reason][0][0];
1859 }
1860 
1861 void Deoptimization::print_statistics() {
1862   juint total = total_deoptimization_count();
1863   juint account = total;
1864   if (total != 0) {
1865     ttyLocker ttyl;
1866     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
1867     tty->print_cr("Deoptimization traps recorded:");
1868     #define PRINT_STAT_LINE(name, r) \
1869       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1870     PRINT_STAT_LINE("total", total);
1871     // For each non-zero entry in the histogram, print the reason,
1872     // the action, and (if specifically known) the type of bytecode.
1873     for (int reason = 0; reason < Reason_LIMIT; reason++) {
1874       for (int action = 0; action < Action_LIMIT; action++) {
1875         juint* cases = _deoptimization_hist[reason][1+action];
1876         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1877           juint counter = cases[bc_case];
1878           if (counter != 0) {
1879             char name[1*K];
1880             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1881             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1882               bc = Bytecodes::_illegal;
1883             sprintf(name, "%s/%s/%s",
1884                     trap_reason_name(reason),
1885                     trap_action_name(action),
1886                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1887             juint r = counter >> LSB_BITS;
1888             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1889             account -= r;
1890           }
1891         }
1892       }
1893     }
1894     if (account != 0) {
1895       PRINT_STAT_LINE("unaccounted", account);
1896     }
1897     #undef PRINT_STAT_LINE
1898     if (xtty != NULL)  xtty->tail("statistics");
1899   }
1900 }
1901 #else // COMPILER2 || SHARK
1902 
1903 
1904 // Stubs for C1 only system.
1905 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1906   return false;
1907 }
1908 
1909 const char* Deoptimization::trap_reason_name(int reason) {
1910   return "unknown";
1911 }
1912 
1913 void Deoptimization::print_statistics() {
1914   // no output
1915 }
1916 
1917 void
1918 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
1919   // no udpate
1920 }
1921 
1922 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1923   return 0;
1924 }
1925 
1926 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1927                                        Bytecodes::Code bc) {
1928   // no update
1929 }
1930 
1931 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1932                                               int trap_state) {
1933   jio_snprintf(buf, buflen, "#%d", trap_state);
1934   return buf;
1935 }
1936 
1937 #endif // COMPILER2 || SHARK