1 /*
   2  * Copyright (c) 1997, 2012, 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/method.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  caller_actual_parameters,
  94                                          int  number_of_frames,
  95                                          intptr_t* frame_sizes,
  96                                          address* frame_pcs,
  97                                          BasicType return_type) {
  98   _size_of_deoptimized_frame = size_of_deoptimized_frame;
  99   _caller_adjustment         = caller_adjustment;
 100   _caller_actual_parameters  = caller_actual_parameters;
 101   _number_of_frames          = number_of_frames;
 102   _frame_sizes               = frame_sizes;
 103   _frame_pcs                 = frame_pcs;
 104   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2, mtCompiler);
 105   _return_type               = return_type;
 106   _initial_info              = 0;
 107   // PD (x86 only)
 108   _counter_temp              = 0;
 109   _unpack_kind               = 0;
 110   _sender_sp_temp            = 0;
 111 
 112   _total_frame_sizes         = size_of_frames();
 113 }
 114 
 115 
 116 Deoptimization::UnrollBlock::~UnrollBlock() {
 117   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes, mtCompiler);
 118   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs, mtCompiler);
 119   FREE_C_HEAP_ARRAY(intptr_t, _register_block, mtCompiler);
 120 }
 121 
 122 
 123 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
 124   assert(register_number < RegisterMap::reg_count, "checking register number");
 125   return &_register_block[register_number * 2];
 126 }
 127 
 128 
 129 
 130 int Deoptimization::UnrollBlock::size_of_frames() const {
 131   // Acount first for the adjustment of the initial frame
 132   int result = _caller_adjustment;
 133   for (int index = 0; index < number_of_frames(); index++) {
 134     result += frame_sizes()[index];
 135   }
 136   return result;
 137 }
 138 
 139 
 140 void Deoptimization::UnrollBlock::print() {
 141   ttyLocker ttyl;
 142   tty->print_cr("UnrollBlock");
 143   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
 144   tty->print(   "  frame_sizes: ");
 145   for (int index = 0; index < number_of_frames(); index++) {
 146     tty->print("%d ", frame_sizes()[index]);
 147   }
 148   tty->cr();
 149 }
 150 
 151 
 152 // In order to make fetch_unroll_info work properly with escape
 153 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
 154 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
 155 // of previously eliminated objects occurs in realloc_objects, which is
 156 // called from the method fetch_unroll_info_helper below.
 157 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
 158   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 159   // but makes the entry a little slower. There is however a little dance we have to
 160   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 161 
 162   // fetch_unroll_info() is called at the beginning of the deoptimization
 163   // handler. Note this fact before we start generating temporary frames
 164   // that can confuse an asynchronous stack walker. This counter is
 165   // decremented at the end of unpack_frames().
 166   thread->inc_in_deopt_handler();
 167 
 168   return fetch_unroll_info_helper(thread);
 169 JRT_END
 170 
 171 
 172 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
 173 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
 174 
 175   // Note: there is a safepoint safety issue here. No matter whether we enter
 176   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
 177   // the vframeArray is created.
 178   //
 179 
 180   // Allocate our special deoptimization ResourceMark
 181   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
 182   assert(thread->deopt_mark() == NULL, "Pending deopt!");
 183   thread->set_deopt_mark(dmark);
 184 
 185   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
 186   RegisterMap map(thread, true);
 187   RegisterMap dummy_map(thread, false);
 188   // Now get the deoptee with a valid map
 189   frame deoptee = stub_frame.sender(&map);
 190   // Set the deoptee nmethod
 191   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
 192   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
 193 
 194   if (VerifyStack) {
 195     thread->validate_frame_layout();
 196   }
 197 
 198   // Create a growable array of VFrames where each VFrame represents an inlined
 199   // Java frame.  This storage is allocated with the usual system arena.
 200   assert(deoptee.is_compiled_frame(), "Wrong frame type");
 201   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
 202   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
 203   while (!vf->is_top()) {
 204     assert(vf->is_compiled_frame(), "Wrong frame type");
 205     chunk->push(compiledVFrame::cast(vf));
 206     vf = vf->sender();
 207   }
 208   assert(vf->is_compiled_frame(), "Wrong frame type");
 209   chunk->push(compiledVFrame::cast(vf));
 210 
 211 #ifdef COMPILER2
 212   // Reallocate the non-escaping objects and restore their fields. Then
 213   // relock objects if synchronization on them was eliminated.
 214   if (DoEscapeAnalysis || EliminateNestedLocks) {
 215     if (EliminateAllocations) {
 216       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
 217       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
 218 
 219       // The flag return_oop() indicates call sites which return oop
 220       // in compiled code. Such sites include java method calls,
 221       // runtime calls (for example, used to allocate new objects/arrays
 222       // on slow code path) and any other calls generated in compiled code.
 223       // It is not guaranteed that we can get such information here only
 224       // by analyzing bytecode in deoptimized frames. This is why this flag
 225       // is set during method compilation (see Compile::Process_OopMap_Node()).
 226       bool save_oop_result = chunk->at(0)->scope()->return_oop();
 227       Handle return_value;
 228       if (save_oop_result) {
 229         // Reallocation may trigger GC. If deoptimization happened on return from
 230         // call which returns oop we need to save it since it is not in oopmap.
 231         oop result = deoptee.saved_oop_result(&map);
 232         assert(result == NULL || result->is_oop(), "must be oop");
 233         return_value = Handle(thread, result);
 234         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
 235         if (TraceDeoptimization) {
 236           ttyLocker ttyl;
 237           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
 238         }
 239       }
 240       bool reallocated = false;
 241       if (objects != NULL) {
 242         JRT_BLOCK
 243           reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
 244         JRT_END
 245       }
 246       if (reallocated) {
 247         reassign_fields(&deoptee, &map, objects);
 248 #ifndef PRODUCT
 249         if (TraceDeoptimization) {
 250           ttyLocker ttyl;
 251           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
 252           print_objects(objects);
 253         }
 254 #endif
 255       }
 256       if (save_oop_result) {
 257         // Restore result.
 258         deoptee.set_saved_oop_result(&map, return_value());
 259       }
 260     }
 261     if (EliminateLocks) {
 262 #ifndef PRODUCT
 263       bool first = true;
 264 #endif
 265       for (int i = 0; i < chunk->length(); i++) {
 266         compiledVFrame* cvf = chunk->at(i);
 267         assert (cvf->scope() != NULL,"expect only compiled java frames");
 268         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
 269         if (monitors->is_nonempty()) {
 270           relock_objects(monitors, thread);
 271 #ifndef PRODUCT
 272           if (TraceDeoptimization) {
 273             ttyLocker ttyl;
 274             for (int j = 0; j < monitors->length(); j++) {
 275               MonitorInfo* mi = monitors->at(j);
 276               if (mi->eliminated()) {
 277                 if (first) {
 278                   first = false;
 279                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
 280                 }
 281                 tty->print_cr("     object <" INTPTR_FORMAT "> locked", mi->owner());
 282               }
 283             }
 284           }
 285 #endif
 286         }
 287       }
 288     }
 289   }
 290 #endif // COMPILER2
 291   // Ensure that no safepoint is taken after pointers have been stored
 292   // in fields of rematerialized objects.  If a safepoint occurs from here on
 293   // out the java state residing in the vframeArray will be missed.
 294   No_Safepoint_Verifier no_safepoint;
 295 
 296   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
 297 
 298   assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
 299   thread->set_vframe_array_head(array);
 300 
 301   // Now that the vframeArray has been created if we have any deferred local writes
 302   // added by jvmti then we can free up that structure as the data is now in the
 303   // vframeArray
 304 
 305   if (thread->deferred_locals() != NULL) {
 306     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
 307     int i = 0;
 308     do {
 309       // Because of inlining we could have multiple vframes for a single frame
 310       // and several of the vframes could have deferred writes. Find them all.
 311       if (list->at(i)->id() == array->original().id()) {
 312         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
 313         list->remove_at(i);
 314         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
 315         delete dlv;
 316       } else {
 317         i++;
 318       }
 319     } while ( i < list->length() );
 320     if (list->length() == 0) {
 321       thread->set_deferred_locals(NULL);
 322       // free the list and elements back to C heap.
 323       delete list;
 324     }
 325 
 326   }
 327 
 328 #ifndef SHARK
 329   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
 330   CodeBlob* cb = stub_frame.cb();
 331   // Verify we have the right vframeArray
 332   assert(cb->frame_size() >= 0, "Unexpected frame size");
 333   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
 334 
 335   // If the deopt call site is a MethodHandle invoke call site we have
 336   // to adjust the unpack_sp.
 337   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
 338   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
 339     unpack_sp = deoptee.unextended_sp();
 340 
 341 #ifdef ASSERT
 342   assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
 343 #endif
 344 #else
 345   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
 346 #endif // !SHARK
 347 
 348   // This is a guarantee instead of an assert because if vframe doesn't match
 349   // we will unpack the wrong deoptimized frame and wind up in strange places
 350   // where it will be very difficult to figure out what went wrong. Better
 351   // to die an early death here than some very obscure death later when the
 352   // trail is cold.
 353   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
 354   // in that it will fail to detect a problem when there is one. This needs
 355   // more work in tiger timeframe.
 356   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
 357 
 358   int number_of_frames = array->frames();
 359 
 360   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
 361   // virtual activation, which is the reverse of the elements in the vframes array.
 362   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames, mtCompiler);
 363   // +1 because we always have an interpreter return address for the final slot.
 364   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1, mtCompiler);
 365   int popframe_extra_args = 0;
 366   // Create an interpreter return address for the stub to use as its return
 367   // address so the skeletal frames are perfectly walkable
 368   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
 369 
 370   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
 371   // activation be put back on the expression stack of the caller for reexecution
 372   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
 373     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
 374   }
 375 
 376   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
 377   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
 378   // than simply use array->sender.pc(). This requires us to walk the current set of frames
 379   //
 380   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
 381   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
 382 
 383   // It's possible that the number of paramters at the call site is
 384   // different than number of arguments in the callee when method
 385   // handles are used.  If the caller is interpreted get the real
 386   // value so that the proper amount of space can be added to it's
 387   // frame.
 388   bool caller_was_method_handle = false;
 389   if (deopt_sender.is_interpreted_frame()) {
 390     methodHandle method = deopt_sender.interpreter_frame_method();
 391     Bytecode_invoke cur = Bytecode_invoke_check(method, deopt_sender.interpreter_frame_bci());
 392     if (cur.is_invokedynamic() || cur.is_invokehandle()) {
 393       // Method handle invokes may involve fairly arbitrary chains of
 394       // calls so it's impossible to know how much actual space the
 395       // caller has for locals.
 396       caller_was_method_handle = true;
 397     }
 398   }
 399 
 400   //
 401   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
 402   // frame_sizes/frame_pcs[1] next oldest frame (int)
 403   // frame_sizes/frame_pcs[n] youngest frame (int)
 404   //
 405   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
 406   // owns the space for the return address to it's caller).  Confusing ain't it.
 407   //
 408   // The vframe array can address vframes with indices running from
 409   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
 410   // When we create the skeletal frames we need the oldest frame to be in the zero slot
 411   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
 412   // so things look a little strange in this loop.
 413   //
 414   int callee_parameters = 0;
 415   int callee_locals = 0;
 416   for (int index = 0; index < array->frames(); index++ ) {
 417     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
 418     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
 419     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
 420     int caller_parms = callee_parameters;
 421     if ((index == array->frames() - 1) && caller_was_method_handle) {
 422       caller_parms = 0;
 423     }
 424     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(caller_parms,
 425                                                                                                     callee_parameters,
 426                                                                                                     callee_locals,
 427                                                                                                     index == 0,
 428                                                                                                     index == array->frames() - 1,
 429                                                                                                     popframe_extra_args);
 430     // This pc doesn't have to be perfect just good enough to identify the frame
 431     // as interpreted so the skeleton frame will be walkable
 432     // The correct pc will be set when the skeleton frame is completely filled out
 433     // The final pc we store in the loop is wrong and will be overwritten below
 434     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
 435 
 436     callee_parameters = array->element(index)->method()->size_of_parameters();
 437     callee_locals = array->element(index)->method()->max_locals();
 438     popframe_extra_args = 0;
 439   }
 440 
 441   // Compute whether the root vframe returns a float or double value.
 442   BasicType return_type;
 443   {
 444     HandleMark hm;
 445     methodHandle method(thread, array->element(0)->method());
 446     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
 447     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
 448   }
 449 
 450   // Compute information for handling adapters and adjusting the frame size of the caller.
 451   int caller_adjustment = 0;
 452 
 453   // Compute the amount the oldest interpreter frame will have to adjust
 454   // its caller's stack by. If the caller is a compiled frame then
 455   // we pretend that the callee has no parameters so that the
 456   // extension counts for the full amount of locals and not just
 457   // locals-parms. This is because without a c2i adapter the parm
 458   // area as created by the compiled frame will not be usable by
 459   // the interpreter. (Depending on the calling convention there
 460   // may not even be enough space).
 461 
 462   // QQQ I'd rather see this pushed down into last_frame_adjust
 463   // and have it take the sender (aka caller).
 464 
 465   if (deopt_sender.is_compiled_frame() || caller_was_method_handle) {
 466     caller_adjustment = last_frame_adjust(0, callee_locals);
 467   } else if (callee_locals > callee_parameters) {
 468     // The caller frame may need extending to accommodate
 469     // non-parameter locals of the first unpacked interpreted frame.
 470     // Compute that adjustment.
 471     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
 472   }
 473 
 474   // If the sender is deoptimized the we must retrieve the address of the handler
 475   // since the frame will "magically" show the original pc before the deopt
 476   // and we'd undo the deopt.
 477 
 478   frame_pcs[0] = deopt_sender.raw_pc();
 479 
 480 #ifndef SHARK
 481   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
 482 #endif // SHARK
 483 
 484   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
 485                                       caller_adjustment * BytesPerWord,
 486                                       caller_was_method_handle ? 0 : callee_parameters,
 487                                       number_of_frames,
 488                                       frame_sizes,
 489                                       frame_pcs,
 490                                       return_type);
 491   // On some platforms, we need a way to pass some platform dependent
 492   // information to the unpacking code so the skeletal frames come out
 493   // correct (initial fp value, unextended sp, ...)
 494   info->set_initial_info((intptr_t) array->sender().initial_deoptimization_info());
 495 
 496   if (array->frames() > 1) {
 497     if (VerifyStack && TraceDeoptimization) {
 498       ttyLocker ttyl;
 499       tty->print_cr("Deoptimizing method containing inlining");
 500     }
 501   }
 502 
 503   array->set_unroll_block(info);
 504   return info;
 505 }
 506 
 507 // Called to cleanup deoptimization data structures in normal case
 508 // after unpacking to stack and when stack overflow error occurs
 509 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
 510                                         vframeArray *array) {
 511 
 512   // Get array if coming from exception
 513   if (array == NULL) {
 514     array = thread->vframe_array_head();
 515   }
 516   thread->set_vframe_array_head(NULL);
 517 
 518   // Free the previous UnrollBlock
 519   vframeArray* old_array = thread->vframe_array_last();
 520   thread->set_vframe_array_last(array);
 521 
 522   if (old_array != NULL) {
 523     UnrollBlock* old_info = old_array->unroll_block();
 524     old_array->set_unroll_block(NULL);
 525     delete old_info;
 526     delete old_array;
 527   }
 528 
 529   // Deallocate any resource creating in this routine and any ResourceObjs allocated
 530   // inside the vframeArray (StackValueCollections)
 531 
 532   delete thread->deopt_mark();
 533   thread->set_deopt_mark(NULL);
 534   thread->set_deopt_nmethod(NULL);
 535 
 536 
 537   if (JvmtiExport::can_pop_frame()) {
 538 #ifndef CC_INTERP
 539     // Regardless of whether we entered this routine with the pending
 540     // popframe condition bit set, we should always clear it now
 541     thread->clear_popframe_condition();
 542 #else
 543     // C++ interpeter will clear has_pending_popframe when it enters
 544     // with method_resume. For deopt_resume2 we clear it now.
 545     if (thread->popframe_forcing_deopt_reexecution())
 546         thread->clear_popframe_condition();
 547 #endif /* CC_INTERP */
 548   }
 549 
 550   // unpack_frames() is called at the end of the deoptimization handler
 551   // and (in C2) at the end of the uncommon trap handler. Note this fact
 552   // so that an asynchronous stack walker can work again. This counter is
 553   // incremented at the beginning of fetch_unroll_info() and (in C2) at
 554   // the beginning of uncommon_trap().
 555   thread->dec_in_deopt_handler();
 556 }
 557 
 558 
 559 // Return BasicType of value being returned
 560 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
 561 
 562   // We are already active int he special DeoptResourceMark any ResourceObj's we
 563   // allocate will be freed at the end of the routine.
 564 
 565   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
 566   // but makes the entry a little slower. There is however a little dance we have to
 567   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
 568   ResetNoHandleMark rnhm; // No-op in release/product versions
 569   HandleMark hm;
 570 
 571   frame stub_frame = thread->last_frame();
 572 
 573   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
 574   // must point to the vframeArray for the unpack frame.
 575   vframeArray* array = thread->vframe_array_head();
 576 
 577 #ifndef PRODUCT
 578   if (TraceDeoptimization) {
 579     ttyLocker ttyl;
 580     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
 581   }
 582 #endif
 583   Events::log(thread, "DEOPT UNPACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT " mode %d",
 584               stub_frame.pc(), stub_frame.sp(), exec_mode);
 585 
 586   UnrollBlock* info = array->unroll_block();
 587 
 588   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
 589   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
 590 
 591   BasicType bt = info->return_type();
 592 
 593   // If we have an exception pending, claim that the return type is an oop
 594   // so the deopt_blob does not overwrite the exception_oop.
 595 
 596   if (exec_mode == Unpack_exception)
 597     bt = T_OBJECT;
 598 
 599   // Cleanup thread deopt data
 600   cleanup_deopt_info(thread, array);
 601 
 602 #ifndef PRODUCT
 603   if (VerifyStack) {
 604     ResourceMark res_mark;
 605 
 606     thread->validate_frame_layout();
 607 
 608     // Verify that the just-unpacked frames match the interpreter's
 609     // notions of expression stack and locals
 610     vframeArray* cur_array = thread->vframe_array_last();
 611     RegisterMap rm(thread, false);
 612     rm.set_include_argument_oops(false);
 613     bool is_top_frame = true;
 614     int callee_size_of_parameters = 0;
 615     int callee_max_locals = 0;
 616     for (int i = 0; i < cur_array->frames(); i++) {
 617       vframeArrayElement* el = cur_array->element(i);
 618       frame* iframe = el->iframe();
 619       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
 620 
 621       // Get the oop map for this bci
 622       InterpreterOopMap mask;
 623       int cur_invoke_parameter_size = 0;
 624       bool try_next_mask = false;
 625       int next_mask_expression_stack_size = -1;
 626       int top_frame_expression_stack_adjustment = 0;
 627       methodHandle mh(thread, iframe->interpreter_frame_method());
 628       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
 629       BytecodeStream str(mh);
 630       str.set_start(iframe->interpreter_frame_bci());
 631       int max_bci = mh->code_size();
 632       // Get to the next bytecode if possible
 633       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
 634       // Check to see if we can grab the number of outgoing arguments
 635       // at an uncommon trap for an invoke (where the compiler
 636       // generates debug info before the invoke has executed)
 637       Bytecodes::Code cur_code = str.next();
 638       if (cur_code == Bytecodes::_invokevirtual ||
 639           cur_code == Bytecodes::_invokespecial ||
 640           cur_code == Bytecodes::_invokestatic  ||
 641           cur_code == Bytecodes::_invokeinterface) {
 642         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
 643         Symbol* signature = invoke.signature();
 644         ArgumentSizeComputer asc(signature);
 645         cur_invoke_parameter_size = asc.size();
 646         if (cur_code != Bytecodes::_invokestatic) {
 647           // Add in receiver
 648           ++cur_invoke_parameter_size;
 649         }
 650       }
 651       if (str.bci() < max_bci) {
 652         Bytecodes::Code bc = str.next();
 653         if (bc >= 0) {
 654           // The interpreter oop map generator reports results before
 655           // the current bytecode has executed except in the case of
 656           // calls. It seems to be hard to tell whether the compiler
 657           // has emitted debug information matching the "state before"
 658           // a given bytecode or the state after, so we try both
 659           switch (cur_code) {
 660             case Bytecodes::_invokevirtual:
 661             case Bytecodes::_invokespecial:
 662             case Bytecodes::_invokestatic:
 663             case Bytecodes::_invokeinterface:
 664             case Bytecodes::_athrow:
 665               break;
 666             default: {
 667               InterpreterOopMap next_mask;
 668               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
 669               next_mask_expression_stack_size = next_mask.expression_stack_size();
 670               // Need to subtract off the size of the result type of
 671               // the bytecode because this is not described in the
 672               // debug info but returned to the interpreter in the TOS
 673               // caching register
 674               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
 675               if (bytecode_result_type != T_ILLEGAL) {
 676                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
 677               }
 678               assert(top_frame_expression_stack_adjustment >= 0, "");
 679               try_next_mask = true;
 680               break;
 681             }
 682           }
 683         }
 684       }
 685 
 686       // Verify stack depth and oops in frame
 687       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
 688       if (!(
 689             /* SPARC */
 690             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
 691             /* x86 */
 692             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
 693             (try_next_mask &&
 694              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
 695                                                                     top_frame_expression_stack_adjustment))) ||
 696             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
 697             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
 698              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
 699             )) {
 700         ttyLocker ttyl;
 701 
 702         // Print out some information that will help us debug the problem
 703         tty->print_cr("Wrong number of expression stack elements during deoptimization");
 704         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
 705         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
 706                       iframe->interpreter_frame_expression_stack_size());
 707         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
 708         tty->print_cr("  try_next_mask = %d", try_next_mask);
 709         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
 710         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
 711         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
 712         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
 713         tty->print_cr("  exec_mode = %d", exec_mode);
 714         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
 715         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
 716         tty->print_cr("  Interpreted frames:");
 717         for (int k = 0; k < cur_array->frames(); k++) {
 718           vframeArrayElement* el = cur_array->element(k);
 719           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
 720         }
 721         cur_array->print_on_2(tty);
 722         guarantee(false, "wrong number of expression stack elements during deopt");
 723       }
 724       VerifyOopClosure verify;
 725       iframe->oops_interpreted_do(&verify, NULL, &rm, false);
 726       callee_size_of_parameters = mh->size_of_parameters();
 727       callee_max_locals = mh->max_locals();
 728       is_top_frame = false;
 729     }
 730   }
 731 #endif /* !PRODUCT */
 732 
 733 
 734   return bt;
 735 JRT_END
 736 
 737 
 738 int Deoptimization::deoptimize_dependents() {
 739   Threads::deoptimized_wrt_marked_nmethods();
 740   return 0;
 741 }
 742 
 743 
 744 #ifdef COMPILER2
 745 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
 746   Handle pending_exception(thread->pending_exception());
 747   const char* exception_file = thread->exception_file();
 748   int exception_line = thread->exception_line();
 749   thread->clear_pending_exception();
 750 
 751   for (int i = 0; i < objects->length(); i++) {
 752     assert(objects->at(i)->is_object(), "invalid debug information");
 753     ObjectValue* sv = (ObjectValue*) objects->at(i);
 754 
 755     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 756     oop obj = NULL;
 757 
 758     if (k->oop_is_instance()) {
 759       InstanceKlass* ik = InstanceKlass::cast(k());
 760       obj = ik->allocate_instance(CHECK_(false));
 761     } else if (k->oop_is_typeArray()) {
 762       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 763       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
 764       int len = sv->field_size() / type2size[ak->element_type()];
 765       obj = ak->allocate(len, CHECK_(false));
 766     } else if (k->oop_is_objArray()) {
 767       ObjArrayKlass* ak = ObjArrayKlass::cast(k());
 768       obj = ak->allocate(sv->field_size(), CHECK_(false));
 769     }
 770 
 771     assert(obj != NULL, "allocation failed");
 772     assert(sv->value().is_null(), "redundant reallocation");
 773     sv->set_value(obj);
 774   }
 775 
 776   if (pending_exception.not_null()) {
 777     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
 778   }
 779 
 780   return true;
 781 }
 782 
 783 // This assumes that the fields are stored in ObjectValue in the same order
 784 // they are yielded by do_nonstatic_fields.
 785 class FieldReassigner: public FieldClosure {
 786   frame* _fr;
 787   RegisterMap* _reg_map;
 788   ObjectValue* _sv;
 789   InstanceKlass* _ik;
 790   oop _obj;
 791 
 792   int _i;
 793 public:
 794   FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
 795     _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
 796 
 797   int i() const { return _i; }
 798 
 799 
 800   void do_field(fieldDescriptor* fd) {
 801     intptr_t val;
 802     StackValue* value =
 803       StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
 804     int offset = fd->offset();
 805     switch (fd->field_type()) {
 806     case T_OBJECT: case T_ARRAY:
 807       assert(value->type() == T_OBJECT, "Agreement.");
 808       _obj->obj_field_put(offset, value->get_obj()());
 809       break;
 810 
 811     case T_LONG: case T_DOUBLE: {
 812       assert(value->type() == T_INT, "Agreement.");
 813       StackValue* low =
 814         StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
 815 #ifdef _LP64
 816       jlong res = (jlong)low->get_int();
 817 #else
 818 #ifdef SPARC
 819       // For SPARC we have to swap high and low words.
 820       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 821 #else
 822       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 823 #endif //SPARC
 824 #endif
 825       _obj->long_field_put(offset, res);
 826       break;
 827     }
 828     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 829     case T_INT: case T_FLOAT: // 4 bytes.
 830       assert(value->type() == T_INT, "Agreement.");
 831       val = value->get_int();
 832       _obj->int_field_put(offset, (jint)*((jint*)&val));
 833       break;
 834 
 835     case T_SHORT: case T_CHAR: // 2 bytes
 836       assert(value->type() == T_INT, "Agreement.");
 837       val = value->get_int();
 838       _obj->short_field_put(offset, (jshort)*((jint*)&val));
 839       break;
 840 
 841     case T_BOOLEAN: case T_BYTE: // 1 byte
 842       assert(value->type() == T_INT, "Agreement.");
 843       val = value->get_int();
 844       _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
 845       break;
 846 
 847     default:
 848       ShouldNotReachHere();
 849     }
 850     _i++;
 851   }
 852 };
 853 
 854 // restore elements of an eliminated type array
 855 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
 856   int index = 0;
 857   intptr_t val;
 858 
 859   for (int i = 0; i < sv->field_size(); i++) {
 860     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 861     switch(type) {
 862     case T_LONG: case T_DOUBLE: {
 863       assert(value->type() == T_INT, "Agreement.");
 864       StackValue* low =
 865         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
 866 #ifdef _LP64
 867       jlong res = (jlong)low->get_int();
 868 #else
 869 #ifdef SPARC
 870       // For SPARC we have to swap high and low words.
 871       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
 872 #else
 873       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
 874 #endif //SPARC
 875 #endif
 876       obj->long_at_put(index, res);
 877       break;
 878     }
 879 
 880     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
 881     case T_INT: case T_FLOAT: // 4 bytes.
 882       assert(value->type() == T_INT, "Agreement.");
 883       val = value->get_int();
 884       obj->int_at_put(index, (jint)*((jint*)&val));
 885       break;
 886 
 887     case T_SHORT: case T_CHAR: // 2 bytes
 888       assert(value->type() == T_INT, "Agreement.");
 889       val = value->get_int();
 890       obj->short_at_put(index, (jshort)*((jint*)&val));
 891       break;
 892 
 893     case T_BOOLEAN: case T_BYTE: // 1 byte
 894       assert(value->type() == T_INT, "Agreement.");
 895       val = value->get_int();
 896       obj->bool_at_put(index, (jboolean)*((jint*)&val));
 897       break;
 898 
 899       default:
 900         ShouldNotReachHere();
 901     }
 902     index++;
 903   }
 904 }
 905 
 906 
 907 // restore fields of an eliminated object array
 908 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
 909   for (int i = 0; i < sv->field_size(); i++) {
 910     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
 911     assert(value->type() == T_OBJECT, "object element expected");
 912     obj->obj_at_put(i, value->get_obj()());
 913   }
 914 }
 915 
 916 
 917 // restore fields of all eliminated objects and arrays
 918 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
 919   for (int i = 0; i < objects->length(); i++) {
 920     ObjectValue* sv = (ObjectValue*) objects->at(i);
 921     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 922     Handle obj = sv->value();
 923     assert(obj.not_null(), "reallocation was missed");
 924 
 925     if (k->oop_is_instance()) {
 926       InstanceKlass* ik = InstanceKlass::cast(k());
 927       FieldReassigner reassign(fr, reg_map, sv, obj());
 928       ik->do_nonstatic_fields(&reassign);
 929     } else if (k->oop_is_typeArray()) {
 930       TypeArrayKlass* ak = TypeArrayKlass::cast(k());
 931       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
 932     } else if (k->oop_is_objArray()) {
 933       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
 934     }
 935   }
 936 }
 937 
 938 
 939 // relock objects for which synchronization was eliminated
 940 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
 941   for (int i = 0; i < monitors->length(); i++) {
 942     MonitorInfo* mon_info = monitors->at(i);
 943     if (mon_info->eliminated()) {
 944       assert(mon_info->owner() != NULL, "reallocation was missed");
 945       Handle obj = Handle(mon_info->owner());
 946       markOop mark = obj->mark();
 947       if (UseBiasedLocking && mark->has_bias_pattern()) {
 948         // New allocated objects may have the mark set to anonymously biased.
 949         // Also the deoptimized method may called methods with synchronization
 950         // where the thread-local object is bias locked to the current thread.
 951         assert(mark->is_biased_anonymously() ||
 952                mark->biased_locker() == thread, "should be locked to current thread");
 953         // Reset mark word to unbiased prototype.
 954         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
 955         obj->set_mark(unbiased_prototype);
 956       }
 957       BasicLock* lock = mon_info->lock();
 958       ObjectSynchronizer::slow_enter(obj, lock, thread);
 959     }
 960     assert(mon_info->owner()->is_locked(), "object must be locked now");
 961   }
 962 }
 963 
 964 
 965 #ifndef PRODUCT
 966 // print information about reallocated objects
 967 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
 968   fieldDescriptor fd;
 969 
 970   for (int i = 0; i < objects->length(); i++) {
 971     ObjectValue* sv = (ObjectValue*) objects->at(i);
 972     KlassHandle k(java_lang_Class::as_Klass(sv->klass()->as_ConstantOopReadValue()->value()()));
 973     Handle obj = sv->value();
 974 
 975     tty->print("     object <" INTPTR_FORMAT "> of type ", sv->value()());
 976     k->print_value();
 977     tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
 978     tty->cr();
 979 
 980     if (Verbose) {
 981       k->oop_print_on(obj(), tty);
 982     }
 983   }
 984 }
 985 #endif
 986 #endif // COMPILER2
 987 
 988 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
 989   Events::log(thread, "DEOPT PACKING pc=" INTPTR_FORMAT " sp=" INTPTR_FORMAT, fr.pc(), fr.sp());
 990 
 991 #ifndef PRODUCT
 992   if (TraceDeoptimization) {
 993     ttyLocker ttyl;
 994     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
 995     fr.print_on(tty);
 996     tty->print_cr("     Virtual frames (innermost first):");
 997     for (int index = 0; index < chunk->length(); index++) {
 998       compiledVFrame* vf = chunk->at(index);
 999       tty->print("       %2d - ", index);
1000       vf->print_value();
1001       int bci = chunk->at(index)->raw_bci();
1002       const char* code_name;
1003       if (bci == SynchronizationEntryBCI) {
1004         code_name = "sync entry";
1005       } else {
1006         Bytecodes::Code code = vf->method()->code_at(bci);
1007         code_name = Bytecodes::name(code);
1008       }
1009       tty->print(" - %s", code_name);
1010       tty->print_cr(" @ bci %d ", bci);
1011       if (Verbose) {
1012         vf->print();
1013         tty->cr();
1014       }
1015     }
1016   }
1017 #endif
1018 
1019   // Register map for next frame (used for stack crawl).  We capture
1020   // the state of the deopt'ing frame's caller.  Thus if we need to
1021   // stuff a C2I adapter we can properly fill in the callee-save
1022   // register locations.
1023   frame caller = fr.sender(reg_map);
1024   int frame_size = caller.sp() - fr.sp();
1025 
1026   frame sender = caller;
1027 
1028   // Since the Java thread being deoptimized will eventually adjust it's own stack,
1029   // the vframeArray containing the unpacking information is allocated in the C heap.
1030   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
1031   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
1032 
1033   // Compare the vframeArray to the collected vframes
1034   assert(array->structural_compare(thread, chunk), "just checking");
1035 
1036 #ifndef PRODUCT
1037   if (TraceDeoptimization) {
1038     ttyLocker ttyl;
1039     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, array);
1040   }
1041 #endif // PRODUCT
1042 
1043   return array;
1044 }
1045 
1046 
1047 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
1048   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
1049   for (int i = 0; i < monitors->length(); i++) {
1050     MonitorInfo* mon_info = monitors->at(i);
1051     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
1052       objects_to_revoke->append(Handle(mon_info->owner()));
1053     }
1054   }
1055 }
1056 
1057 
1058 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
1059   if (!UseBiasedLocking) {
1060     return;
1061   }
1062 
1063   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1064 
1065   // Unfortunately we don't have a RegisterMap available in most of
1066   // the places we want to call this routine so we need to walk the
1067   // stack again to update the register map.
1068   if (map == NULL || !map->update_map()) {
1069     StackFrameStream sfs(thread, true);
1070     bool found = false;
1071     while (!found && !sfs.is_done()) {
1072       frame* cur = sfs.current();
1073       sfs.next();
1074       found = cur->id() == fr.id();
1075     }
1076     assert(found, "frame to be deoptimized not found on target thread's stack");
1077     map = sfs.register_map();
1078   }
1079 
1080   vframe* vf = vframe::new_vframe(&fr, map, thread);
1081   compiledVFrame* cvf = compiledVFrame::cast(vf);
1082   // Revoke monitors' biases in all scopes
1083   while (!cvf->is_top()) {
1084     collect_monitors(cvf, objects_to_revoke);
1085     cvf = compiledVFrame::cast(cvf->sender());
1086   }
1087   collect_monitors(cvf, objects_to_revoke);
1088 
1089   if (SafepointSynchronize::is_at_safepoint()) {
1090     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1091   } else {
1092     BiasedLocking::revoke(objects_to_revoke);
1093   }
1094 }
1095 
1096 
1097 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
1098   if (!UseBiasedLocking) {
1099     return;
1100   }
1101 
1102   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
1103   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
1104   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
1105     if (jt->has_last_Java_frame()) {
1106       StackFrameStream sfs(jt, true);
1107       while (!sfs.is_done()) {
1108         frame* cur = sfs.current();
1109         if (cb->contains(cur->pc())) {
1110           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
1111           compiledVFrame* cvf = compiledVFrame::cast(vf);
1112           // Revoke monitors' biases in all scopes
1113           while (!cvf->is_top()) {
1114             collect_monitors(cvf, objects_to_revoke);
1115             cvf = compiledVFrame::cast(cvf->sender());
1116           }
1117           collect_monitors(cvf, objects_to_revoke);
1118         }
1119         sfs.next();
1120       }
1121     }
1122   }
1123   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
1124 }
1125 
1126 
1127 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
1128   assert(fr.can_be_deoptimized(), "checking frame type");
1129 
1130   gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
1131 
1132   // Patch the nmethod so that when execution returns to it we will
1133   // deopt the execution state and return to the interpreter.
1134   fr.deoptimize(thread);
1135 }
1136 
1137 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
1138   // Deoptimize only if the frame comes from compile code.
1139   // Do not deoptimize the frame which is already patched
1140   // during the execution of the loops below.
1141   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
1142     return;
1143   }
1144   ResourceMark rm;
1145   DeoptimizationMarker dm;
1146   if (UseBiasedLocking) {
1147     revoke_biases_of_monitors(thread, fr, map);
1148   }
1149   deoptimize_single_frame(thread, fr);
1150 
1151 }
1152 
1153 
1154 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
1155   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
1156          "can only deoptimize other thread at a safepoint");
1157   // Compute frame and register map based on thread and sp.
1158   RegisterMap reg_map(thread, UseBiasedLocking);
1159   frame fr = thread->last_frame();
1160   while (fr.id() != id) {
1161     fr = fr.sender(&reg_map);
1162   }
1163   deoptimize(thread, fr, &reg_map);
1164 }
1165 
1166 
1167 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
1168   if (thread == Thread::current()) {
1169     Deoptimization::deoptimize_frame_internal(thread, id);
1170   } else {
1171     VM_DeoptimizeFrame deopt(thread, id);
1172     VMThread::execute(&deopt);
1173   }
1174 }
1175 
1176 
1177 // JVMTI PopFrame support
1178 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
1179 {
1180   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
1181 }
1182 JRT_END
1183 
1184 
1185 #if defined(COMPILER2) || defined(SHARK)
1186 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
1187   // in case of an unresolved klass entry, load the class.
1188   if (constant_pool->tag_at(index).is_unresolved_klass()) {
1189     Klass* tk = constant_pool->klass_at(index, CHECK);
1190     return;
1191   }
1192 
1193   if (!constant_pool->tag_at(index).is_symbol()) return;
1194 
1195   Handle class_loader (THREAD, constant_pool->pool_holder()->class_loader());
1196   Symbol*  symbol  = constant_pool->symbol_at(index);
1197 
1198   // class name?
1199   if (symbol->byte_at(0) != '(') {
1200     Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1201     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
1202     return;
1203   }
1204 
1205   // then it must be a signature!
1206   ResourceMark rm(THREAD);
1207   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
1208     if (ss.is_object()) {
1209       Symbol* class_name = ss.as_symbol(CHECK);
1210       Handle protection_domain (THREAD, constant_pool->pool_holder()->protection_domain());
1211       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
1212     }
1213   }
1214 }
1215 
1216 
1217 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
1218   EXCEPTION_MARK;
1219   load_class_by_index(constant_pool, index, THREAD);
1220   if (HAS_PENDING_EXCEPTION) {
1221     // Exception happened during classloading. We ignore the exception here, since it
1222     // is going to be rethrown since the current activation is going to be deoptimzied and
1223     // the interpreter will re-execute the bytecode.
1224     CLEAR_PENDING_EXCEPTION;
1225   }
1226 }
1227 
1228 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
1229   HandleMark hm;
1230 
1231   // uncommon_trap() is called at the beginning of the uncommon trap
1232   // handler. Note this fact before we start generating temporary frames
1233   // that can confuse an asynchronous stack walker. This counter is
1234   // decremented at the end of unpack_frames().
1235   thread->inc_in_deopt_handler();
1236 
1237   // We need to update the map if we have biased locking.
1238   RegisterMap reg_map(thread, UseBiasedLocking);
1239   frame stub_frame = thread->last_frame();
1240   frame fr = stub_frame.sender(&reg_map);
1241   // Make sure the calling nmethod is not getting deoptimized and removed
1242   // before we are done with it.
1243   nmethodLocker nl(fr.pc());
1244 
1245   // Log a message
1246   Events::log(thread, "Uncommon trap: trap_request=" PTR32_FORMAT " fr.pc=" INTPTR_FORMAT,
1247               trap_request, fr.pc());
1248 
1249   {
1250     ResourceMark rm;
1251 
1252     // Revoke biases of any monitors in the frame to ensure we can migrate them
1253     revoke_biases_of_monitors(thread, fr, &reg_map);
1254 
1255     DeoptReason reason = trap_request_reason(trap_request);
1256     DeoptAction action = trap_request_action(trap_request);
1257     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
1258 
1259     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
1260     compiledVFrame* cvf = compiledVFrame::cast(vf);
1261 
1262     nmethod* nm = cvf->code();
1263 
1264     ScopeDesc*      trap_scope  = cvf->scope();
1265     methodHandle    trap_method = trap_scope->method();
1266     int             trap_bci    = trap_scope->bci();
1267     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
1268 
1269     // Record this event in the histogram.
1270     gather_statistics(reason, action, trap_bc);
1271 
1272     // Ensure that we can record deopt. history:
1273     bool create_if_missing = ProfileTraps;
1274 
1275     MethodData* trap_mdo =
1276       get_method_data(thread, trap_method, create_if_missing);
1277 
1278     // Log a message
1279     Events::log_deopt_message(thread, "Uncommon trap: reason=%s action=%s pc=" INTPTR_FORMAT " method=%s @ %d",
1280                               trap_reason_name(reason), trap_action_name(action), fr.pc(),
1281                               trap_method->name_and_sig_as_C_string(), trap_bci);
1282 
1283     // Print a bunch of diagnostics, if requested.
1284     if (TraceDeoptimization || LogCompilation) {
1285       ResourceMark rm;
1286       ttyLocker ttyl;
1287       char buf[100];
1288       if (xtty != NULL) {
1289         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
1290                          os::current_thread_id(),
1291                          format_trap_request(buf, sizeof(buf), trap_request));
1292         nm->log_identity(xtty);
1293       }
1294       Symbol* class_name = NULL;
1295       bool unresolved = false;
1296       if (unloaded_class_index >= 0) {
1297         constantPoolHandle constants (THREAD, trap_method->constants());
1298         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
1299           class_name = constants->klass_name_at(unloaded_class_index);
1300           unresolved = true;
1301           if (xtty != NULL)
1302             xtty->print(" unresolved='1'");
1303         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
1304           class_name = constants->symbol_at(unloaded_class_index);
1305         }
1306         if (xtty != NULL)
1307           xtty->name(class_name);
1308       }
1309       if (xtty != NULL && trap_mdo != NULL) {
1310         // Dump the relevant MDO state.
1311         // This is the deopt count for the current reason, any previous
1312         // reasons or recompiles seen at this point.
1313         int dcnt = trap_mdo->trap_count(reason);
1314         if (dcnt != 0)
1315           xtty->print(" count='%d'", dcnt);
1316         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
1317         int dos = (pdata == NULL)? 0: pdata->trap_state();
1318         if (dos != 0) {
1319           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
1320           if (trap_state_is_recompiled(dos)) {
1321             int recnt2 = trap_mdo->overflow_recompile_count();
1322             if (recnt2 != 0)
1323               xtty->print(" recompiles2='%d'", recnt2);
1324           }
1325         }
1326       }
1327       if (xtty != NULL) {
1328         xtty->stamp();
1329         xtty->end_head();
1330       }
1331       if (TraceDeoptimization) {  // make noise on the tty
1332         tty->print("Uncommon trap occurred in");
1333         nm->method()->print_short_name(tty);
1334         tty->print(" (@" INTPTR_FORMAT ") thread=" UINTX_FORMAT " reason=%s action=%s unloaded_class_index=%d",
1335                    fr.pc(),
1336                    os::current_thread_id(),
1337                    trap_reason_name(reason),
1338                    trap_action_name(action),
1339                    unloaded_class_index);
1340         if (class_name != NULL) {
1341           tty->print(unresolved ? " unresolved class: " : " symbol: ");
1342           class_name->print_symbol_on(tty);
1343         }
1344         tty->cr();
1345       }
1346       if (xtty != NULL) {
1347         // Log the precise location of the trap.
1348         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
1349           xtty->begin_elem("jvms bci='%d'", sd->bci());
1350           xtty->method(sd->method());
1351           xtty->end_elem();
1352           if (sd->is_top())  break;
1353         }
1354         xtty->tail("uncommon_trap");
1355       }
1356     }
1357     // (End diagnostic printout.)
1358 
1359     // Load class if necessary
1360     if (unloaded_class_index >= 0) {
1361       constantPoolHandle constants(THREAD, trap_method->constants());
1362       load_class_by_index(constants, unloaded_class_index);
1363     }
1364 
1365     // Flush the nmethod if necessary and desirable.
1366     //
1367     // We need to avoid situations where we are re-flushing the nmethod
1368     // because of a hot deoptimization site.  Repeated flushes at the same
1369     // point need to be detected by the compiler and avoided.  If the compiler
1370     // cannot avoid them (or has a bug and "refuses" to avoid them), this
1371     // module must take measures to avoid an infinite cycle of recompilation
1372     // and deoptimization.  There are several such measures:
1373     //
1374     //   1. If a recompilation is ordered a second time at some site X
1375     //   and for the same reason R, the action is adjusted to 'reinterpret',
1376     //   to give the interpreter time to exercise the method more thoroughly.
1377     //   If this happens, the method's overflow_recompile_count is incremented.
1378     //
1379     //   2. If the compiler fails to reduce the deoptimization rate, then
1380     //   the method's overflow_recompile_count will begin to exceed the set
1381     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
1382     //   is adjusted to 'make_not_compilable', and the method is abandoned
1383     //   to the interpreter.  This is a performance hit for hot methods,
1384     //   but is better than a disastrous infinite cycle of recompilations.
1385     //   (Actually, only the method containing the site X is abandoned.)
1386     //
1387     //   3. In parallel with the previous measures, if the total number of
1388     //   recompilations of a method exceeds the much larger set limit
1389     //   PerMethodRecompilationCutoff, the method is abandoned.
1390     //   This should only happen if the method is very large and has
1391     //   many "lukewarm" deoptimizations.  The code which enforces this
1392     //   limit is elsewhere (class nmethod, class Method).
1393     //
1394     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
1395     // to recompile at each bytecode independently of the per-BCI cutoff.
1396     //
1397     // The decision to update code is up to the compiler, and is encoded
1398     // in the Action_xxx code.  If the compiler requests Action_none
1399     // no trap state is changed, no compiled code is changed, and the
1400     // computation suffers along in the interpreter.
1401     //
1402     // The other action codes specify various tactics for decompilation
1403     // and recompilation.  Action_maybe_recompile is the loosest, and
1404     // allows the compiled code to stay around until enough traps are seen,
1405     // and until the compiler gets around to recompiling the trapping method.
1406     //
1407     // The other actions cause immediate removal of the present code.
1408 
1409     bool update_trap_state = true;
1410     bool make_not_entrant = false;
1411     bool make_not_compilable = false;
1412     bool reprofile = false;
1413     switch (action) {
1414     case Action_none:
1415       // Keep the old code.
1416       update_trap_state = false;
1417       break;
1418     case Action_maybe_recompile:
1419       // Do not need to invalidate the present code, but we can
1420       // initiate another
1421       // Start compiler without (necessarily) invalidating the nmethod.
1422       // The system will tolerate the old code, but new code should be
1423       // generated when possible.
1424       break;
1425     case Action_reinterpret:
1426       // Go back into the interpreter for a while, and then consider
1427       // recompiling form scratch.
1428       make_not_entrant = true;
1429       // Reset invocation counter for outer most method.
1430       // This will allow the interpreter to exercise the bytecodes
1431       // for a while before recompiling.
1432       // By contrast, Action_make_not_entrant is immediate.
1433       //
1434       // Note that the compiler will track null_check, null_assert,
1435       // range_check, and class_check events and log them as if they
1436       // had been traps taken from compiled code.  This will update
1437       // the MDO trap history so that the next compilation will
1438       // properly detect hot trap sites.
1439       reprofile = true;
1440       break;
1441     case Action_make_not_entrant:
1442       // Request immediate recompilation, and get rid of the old code.
1443       // Make them not entrant, so next time they are called they get
1444       // recompiled.  Unloaded classes are loaded now so recompile before next
1445       // time they are called.  Same for uninitialized.  The interpreter will
1446       // link the missing class, if any.
1447       make_not_entrant = true;
1448       break;
1449     case Action_make_not_compilable:
1450       // Give up on compiling this method at all.
1451       make_not_entrant = true;
1452       make_not_compilable = true;
1453       break;
1454     default:
1455       ShouldNotReachHere();
1456     }
1457 
1458     // Setting +ProfileTraps fixes the following, on all platforms:
1459     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
1460     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
1461     // recompile relies on a MethodData* to record heroic opt failures.
1462 
1463     // Whether the interpreter is producing MDO data or not, we also need
1464     // to use the MDO to detect hot deoptimization points and control
1465     // aggressive optimization.
1466     bool inc_recompile_count = false;
1467     ProfileData* pdata = NULL;
1468     if (ProfileTraps && update_trap_state && trap_mdo != NULL) {
1469       assert(trap_mdo == get_method_data(thread, trap_method, false), "sanity");
1470       uint this_trap_count = 0;
1471       bool maybe_prior_trap = false;
1472       bool maybe_prior_recompile = false;
1473       pdata = query_update_method_data(trap_mdo, trap_bci, reason,
1474                                    //outputs:
1475                                    this_trap_count,
1476                                    maybe_prior_trap,
1477                                    maybe_prior_recompile);
1478       // Because the interpreter also counts null, div0, range, and class
1479       // checks, these traps from compiled code are double-counted.
1480       // This is harmless; it just means that the PerXTrapLimit values
1481       // are in effect a little smaller than they look.
1482 
1483       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1484       if (per_bc_reason != Reason_none) {
1485         // Now take action based on the partially known per-BCI history.
1486         if (maybe_prior_trap
1487             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
1488           // If there are too many traps at this BCI, force a recompile.
1489           // This will allow the compiler to see the limit overflow, and
1490           // take corrective action, if possible.  The compiler generally
1491           // does not use the exact PerBytecodeTrapLimit value, but instead
1492           // changes its tactics if it sees any traps at all.  This provides
1493           // a little hysteresis, delaying a recompile until a trap happens
1494           // several times.
1495           //
1496           // Actually, since there is only one bit of counter per BCI,
1497           // the possible per-BCI counts are {0,1,(per-method count)}.
1498           // This produces accurate results if in fact there is only
1499           // one hot trap site, but begins to get fuzzy if there are
1500           // many sites.  For example, if there are ten sites each
1501           // trapping two or more times, they each get the blame for
1502           // all of their traps.
1503           make_not_entrant = true;
1504         }
1505 
1506         // Detect repeated recompilation at the same BCI, and enforce a limit.
1507         if (make_not_entrant && maybe_prior_recompile) {
1508           // More than one recompile at this point.
1509           inc_recompile_count = maybe_prior_trap;
1510         }
1511       } else {
1512         // For reasons which are not recorded per-bytecode, we simply
1513         // force recompiles unconditionally.
1514         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
1515         make_not_entrant = true;
1516       }
1517 
1518       // Go back to the compiler if there are too many traps in this method.
1519       if (this_trap_count >= (uint)PerMethodTrapLimit) {
1520         // If there are too many traps in this method, force a recompile.
1521         // This will allow the compiler to see the limit overflow, and
1522         // take corrective action, if possible.
1523         // (This condition is an unlikely backstop only, because the
1524         // PerBytecodeTrapLimit is more likely to take effect first,
1525         // if it is applicable.)
1526         make_not_entrant = true;
1527       }
1528 
1529       // Here's more hysteresis:  If there has been a recompile at
1530       // this trap point already, run the method in the interpreter
1531       // for a while to exercise it more thoroughly.
1532       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
1533         reprofile = true;
1534       }
1535 
1536     }
1537 
1538     // Take requested actions on the method:
1539 
1540     // Recompile
1541     if (make_not_entrant) {
1542       if (!nm->make_not_entrant()) {
1543         return; // the call did not change nmethod's state
1544       }
1545 
1546       if (pdata != NULL) {
1547         // Record the recompilation event, if any.
1548         int tstate0 = pdata->trap_state();
1549         int tstate1 = trap_state_set_recompiled(tstate0, true);
1550         if (tstate1 != tstate0)
1551           pdata->set_trap_state(tstate1);
1552       }
1553     }
1554 
1555     if (inc_recompile_count) {
1556       trap_mdo->inc_overflow_recompile_count();
1557       if ((uint)trap_mdo->overflow_recompile_count() >
1558           (uint)PerBytecodeRecompilationCutoff) {
1559         // Give up on the method containing the bad BCI.
1560         if (trap_method() == nm->method()) {
1561           make_not_compilable = true;
1562         } else {
1563           trap_method->set_not_compilable(CompLevel_full_optimization, true, "overflow_recompile_count > PerBytecodeRecompilationCutoff");
1564           // But give grace to the enclosing nm->method().
1565         }
1566       }
1567     }
1568 
1569     // Reprofile
1570     if (reprofile) {
1571       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
1572     }
1573 
1574     // Give up compiling
1575     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
1576       assert(make_not_entrant, "consistent");
1577       nm->method()->set_not_compilable(CompLevel_full_optimization);
1578     }
1579 
1580   } // Free marked resources
1581 
1582 }
1583 JRT_END
1584 
1585 MethodData*
1586 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
1587                                 bool create_if_missing) {
1588   Thread* THREAD = thread;
1589   MethodData* mdo = m()->method_data();
1590   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
1591     // Build an MDO.  Ignore errors like OutOfMemory;
1592     // that simply means we won't have an MDO to update.
1593     Method::build_interpreter_method_data(m, THREAD);
1594     if (HAS_PENDING_EXCEPTION) {
1595       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
1596       CLEAR_PENDING_EXCEPTION;
1597     }
1598     mdo = m()->method_data();
1599   }
1600   return mdo;
1601 }
1602 
1603 ProfileData*
1604 Deoptimization::query_update_method_data(MethodData* trap_mdo,
1605                                          int trap_bci,
1606                                          Deoptimization::DeoptReason reason,
1607                                          //outputs:
1608                                          uint& ret_this_trap_count,
1609                                          bool& ret_maybe_prior_trap,
1610                                          bool& ret_maybe_prior_recompile) {
1611   uint prior_trap_count = trap_mdo->trap_count(reason);
1612   uint this_trap_count  = trap_mdo->inc_trap_count(reason);
1613 
1614   // If the runtime cannot find a place to store trap history,
1615   // it is estimated based on the general condition of the method.
1616   // If the method has ever been recompiled, or has ever incurred
1617   // a trap with the present reason , then this BCI is assumed
1618   // (pessimistically) to be the culprit.
1619   bool maybe_prior_trap      = (prior_trap_count != 0);
1620   bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
1621   ProfileData* pdata = NULL;
1622 
1623 
1624   // For reasons which are recorded per bytecode, we check per-BCI data.
1625   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
1626   if (per_bc_reason != Reason_none) {
1627     // Find the profile data for this BCI.  If there isn't one,
1628     // try to allocate one from the MDO's set of spares.
1629     // This will let us detect a repeated trap at this point.
1630     pdata = trap_mdo->allocate_bci_to_data(trap_bci);
1631 
1632     if (pdata != NULL) {
1633       // Query the trap state of this profile datum.
1634       int tstate0 = pdata->trap_state();
1635       if (!trap_state_has_reason(tstate0, per_bc_reason))
1636         maybe_prior_trap = false;
1637       if (!trap_state_is_recompiled(tstate0))
1638         maybe_prior_recompile = false;
1639 
1640       // Update the trap state of this profile datum.
1641       int tstate1 = tstate0;
1642       // Record the reason.
1643       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
1644       // Store the updated state on the MDO, for next time.
1645       if (tstate1 != tstate0)
1646         pdata->set_trap_state(tstate1);
1647     } else {
1648       if (LogCompilation && xtty != NULL) {
1649         ttyLocker ttyl;
1650         // Missing MDP?  Leave a small complaint in the log.
1651         xtty->elem("missing_mdp bci='%d'", trap_bci);
1652       }
1653     }
1654   }
1655 
1656   // Return results:
1657   ret_this_trap_count = this_trap_count;
1658   ret_maybe_prior_trap = maybe_prior_trap;
1659   ret_maybe_prior_recompile = maybe_prior_recompile;
1660   return pdata;
1661 }
1662 
1663 void
1664 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1665   ResourceMark rm;
1666   // Ignored outputs:
1667   uint ignore_this_trap_count;
1668   bool ignore_maybe_prior_trap;
1669   bool ignore_maybe_prior_recompile;
1670   query_update_method_data(trap_mdo, trap_bci,
1671                            (DeoptReason)reason,
1672                            ignore_this_trap_count,
1673                            ignore_maybe_prior_trap,
1674                            ignore_maybe_prior_recompile);
1675 }
1676 
1677 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
1678 
1679   // Still in Java no safepoints
1680   {
1681     // This enters VM and may safepoint
1682     uncommon_trap_inner(thread, trap_request);
1683   }
1684   return fetch_unroll_info_helper(thread);
1685 }
1686 
1687 // Local derived constants.
1688 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
1689 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
1690 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
1691 
1692 //---------------------------trap_state_reason---------------------------------
1693 Deoptimization::DeoptReason
1694 Deoptimization::trap_state_reason(int trap_state) {
1695   // This assert provides the link between the width of DataLayout::trap_bits
1696   // and the encoding of "recorded" reasons.  It ensures there are enough
1697   // bits to store all needed reasons in the per-BCI MDO profile.
1698   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1699   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1700   trap_state -= recompile_bit;
1701   if (trap_state == DS_REASON_MASK) {
1702     return Reason_many;
1703   } else {
1704     assert((int)Reason_none == 0, "state=0 => Reason_none");
1705     return (DeoptReason)trap_state;
1706   }
1707 }
1708 //-------------------------trap_state_has_reason-------------------------------
1709 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1710   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
1711   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
1712   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1713   trap_state -= recompile_bit;
1714   if (trap_state == DS_REASON_MASK) {
1715     return -1;  // true, unspecifically (bottom of state lattice)
1716   } else if (trap_state == reason) {
1717     return 1;   // true, definitely
1718   } else if (trap_state == 0) {
1719     return 0;   // false, definitely (top of state lattice)
1720   } else {
1721     return 0;   // false, definitely
1722   }
1723 }
1724 //-------------------------trap_state_add_reason-------------------------------
1725 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
1726   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
1727   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
1728   trap_state -= recompile_bit;
1729   if (trap_state == DS_REASON_MASK) {
1730     return trap_state + recompile_bit;     // already at state lattice bottom
1731   } else if (trap_state == reason) {
1732     return trap_state + recompile_bit;     // the condition is already true
1733   } else if (trap_state == 0) {
1734     return reason + recompile_bit;          // no condition has yet been true
1735   } else {
1736     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
1737   }
1738 }
1739 //-----------------------trap_state_is_recompiled------------------------------
1740 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1741   return (trap_state & DS_RECOMPILE_BIT) != 0;
1742 }
1743 //-----------------------trap_state_set_recompiled-----------------------------
1744 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
1745   if (z)  return trap_state |  DS_RECOMPILE_BIT;
1746   else    return trap_state & ~DS_RECOMPILE_BIT;
1747 }
1748 //---------------------------format_trap_state---------------------------------
1749 // This is used for debugging and diagnostics, including hotspot.log output.
1750 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1751                                               int trap_state) {
1752   DeoptReason reason      = trap_state_reason(trap_state);
1753   bool        recomp_flag = trap_state_is_recompiled(trap_state);
1754   // Re-encode the state from its decoded components.
1755   int decoded_state = 0;
1756   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
1757     decoded_state = trap_state_add_reason(decoded_state, reason);
1758   if (recomp_flag)
1759     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
1760   // If the state re-encodes properly, format it symbolically.
1761   // Because this routine is used for debugging and diagnostics,
1762   // be robust even if the state is a strange value.
1763   size_t len;
1764   if (decoded_state != trap_state) {
1765     // Random buggy state that doesn't decode??
1766     len = jio_snprintf(buf, buflen, "#%d", trap_state);
1767   } else {
1768     len = jio_snprintf(buf, buflen, "%s%s",
1769                        trap_reason_name(reason),
1770                        recomp_flag ? " recompiled" : "");
1771   }
1772   if (len >= buflen)
1773     buf[buflen-1] = '\0';
1774   return buf;
1775 }
1776 
1777 
1778 //--------------------------------statics--------------------------------------
1779 Deoptimization::DeoptAction Deoptimization::_unloaded_action
1780   = Deoptimization::Action_reinterpret;
1781 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
1782   // Note:  Keep this in sync. with enum DeoptReason.
1783   "none",
1784   "null_check",
1785   "null_assert",
1786   "range_check",
1787   "class_check",
1788   "array_check",
1789   "intrinsic",
1790   "bimorphic",
1791   "unloaded",
1792   "uninitialized",
1793   "unreached",
1794   "unhandled",
1795   "constraint",
1796   "div0_check",
1797   "age",
1798   "predicate",
1799   "loop_limit_check"
1800 };
1801 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
1802   // Note:  Keep this in sync. with enum DeoptAction.
1803   "none",
1804   "maybe_recompile",
1805   "reinterpret",
1806   "make_not_entrant",
1807   "make_not_compilable"
1808 };
1809 
1810 const char* Deoptimization::trap_reason_name(int reason) {
1811   if (reason == Reason_many)  return "many";
1812   if ((uint)reason < Reason_LIMIT)
1813     return _trap_reason_name[reason];
1814   static char buf[20];
1815   sprintf(buf, "reason%d", reason);
1816   return buf;
1817 }
1818 const char* Deoptimization::trap_action_name(int action) {
1819   if ((uint)action < Action_LIMIT)
1820     return _trap_action_name[action];
1821   static char buf[20];
1822   sprintf(buf, "action%d", action);
1823   return buf;
1824 }
1825 
1826 // This is used for debugging and diagnostics, including hotspot.log output.
1827 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
1828                                                 int trap_request) {
1829   jint unloaded_class_index = trap_request_index(trap_request);
1830   const char* reason = trap_reason_name(trap_request_reason(trap_request));
1831   const char* action = trap_action_name(trap_request_action(trap_request));
1832   size_t len;
1833   if (unloaded_class_index < 0) {
1834     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
1835                        reason, action);
1836   } else {
1837     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
1838                        reason, action, unloaded_class_index);
1839   }
1840   if (len >= buflen)
1841     buf[buflen-1] = '\0';
1842   return buf;
1843 }
1844 
1845 juint Deoptimization::_deoptimization_hist
1846         [Deoptimization::Reason_LIMIT]
1847     [1 + Deoptimization::Action_LIMIT]
1848         [Deoptimization::BC_CASE_LIMIT]
1849   = {0};
1850 
1851 enum {
1852   LSB_BITS = 8,
1853   LSB_MASK = right_n_bits(LSB_BITS)
1854 };
1855 
1856 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1857                                        Bytecodes::Code bc) {
1858   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1859   assert(action >= 0 && action < Action_LIMIT, "oob");
1860   _deoptimization_hist[Reason_none][0][0] += 1;  // total
1861   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
1862   juint* cases = _deoptimization_hist[reason][1+action];
1863   juint* bc_counter_addr = NULL;
1864   juint  bc_counter      = 0;
1865   // Look for an unused counter, or an exact match to this BC.
1866   if (bc != Bytecodes::_illegal) {
1867     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1868       juint* counter_addr = &cases[bc_case];
1869       juint  counter = *counter_addr;
1870       if ((counter == 0 && bc_counter_addr == NULL)
1871           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
1872         // this counter is either free or is already devoted to this BC
1873         bc_counter_addr = counter_addr;
1874         bc_counter = counter | bc;
1875       }
1876     }
1877   }
1878   if (bc_counter_addr == NULL) {
1879     // Overflow, or no given bytecode.
1880     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
1881     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
1882   }
1883   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
1884 }
1885 
1886 jint Deoptimization::total_deoptimization_count() {
1887   return _deoptimization_hist[Reason_none][0][0];
1888 }
1889 
1890 jint Deoptimization::deoptimization_count(DeoptReason reason) {
1891   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
1892   return _deoptimization_hist[reason][0][0];
1893 }
1894 
1895 void Deoptimization::print_statistics() {
1896   juint total = total_deoptimization_count();
1897   juint account = total;
1898   if (total != 0) {
1899     ttyLocker ttyl;
1900     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
1901     tty->print_cr("Deoptimization traps recorded:");
1902     #define PRINT_STAT_LINE(name, r) \
1903       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
1904     PRINT_STAT_LINE("total", total);
1905     // For each non-zero entry in the histogram, print the reason,
1906     // the action, and (if specifically known) the type of bytecode.
1907     for (int reason = 0; reason < Reason_LIMIT; reason++) {
1908       for (int action = 0; action < Action_LIMIT; action++) {
1909         juint* cases = _deoptimization_hist[reason][1+action];
1910         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
1911           juint counter = cases[bc_case];
1912           if (counter != 0) {
1913             char name[1*K];
1914             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
1915             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
1916               bc = Bytecodes::_illegal;
1917             sprintf(name, "%s/%s/%s",
1918                     trap_reason_name(reason),
1919                     trap_action_name(action),
1920                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
1921             juint r = counter >> LSB_BITS;
1922             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
1923             account -= r;
1924           }
1925         }
1926       }
1927     }
1928     if (account != 0) {
1929       PRINT_STAT_LINE("unaccounted", account);
1930     }
1931     #undef PRINT_STAT_LINE
1932     if (xtty != NULL)  xtty->tail("statistics");
1933   }
1934 }
1935 #else // COMPILER2 || SHARK
1936 
1937 
1938 // Stubs for C1 only system.
1939 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
1940   return false;
1941 }
1942 
1943 const char* Deoptimization::trap_reason_name(int reason) {
1944   return "unknown";
1945 }
1946 
1947 void Deoptimization::print_statistics() {
1948   // no output
1949 }
1950 
1951 void
1952 Deoptimization::update_method_data_from_interpreter(MethodData* trap_mdo, int trap_bci, int reason) {
1953   // no udpate
1954 }
1955 
1956 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
1957   return 0;
1958 }
1959 
1960 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
1961                                        Bytecodes::Code bc) {
1962   // no update
1963 }
1964 
1965 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
1966                                               int trap_state) {
1967   jio_snprintf(buf, buflen, "#%d", trap_state);
1968   return buf;
1969 }
1970 
1971 #endif // COMPILER2 || SHARK