src/share/vm/runtime/deoptimization.cpp

Thu, 12 May 2011 10:29:02 -0700

author
never
date
Thu, 12 May 2011 10:29:02 -0700
changeset 2901
3d2ab563047a
parent 2878
dcfb3dede009
child 3130
5432047c7db7
permissions
-rw-r--r--

7043461: VM crashes in void LinkResolver::runtime_resolve_virtual_method
Reviewed-by: kvn, coleenp

     1 /*
     2  * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved.
     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
     4  *
     5  * This code is free software; you can redistribute it and/or modify it
     6  * under the terms of the GNU General Public License version 2 only, as
     7  * published by the Free Software Foundation.
     8  *
     9  * This code is distributed in the hope that it will be useful, but WITHOUT
    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    12  * version 2 for more details (a copy is included in the LICENSE file that
    13  * accompanied this code).
    14  *
    15  * You should have received a copy of the GNU General Public License version
    16  * 2 along with this work; if not, write to the Free Software Foundation,
    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
    18  *
    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
    20  * or visit www.oracle.com if you need additional information or have any
    21  * questions.
    22  *
    23  */
    25 #include "precompiled.hpp"
    26 #include "classfile/systemDictionary.hpp"
    27 #include "code/debugInfoRec.hpp"
    28 #include "code/nmethod.hpp"
    29 #include "code/pcDesc.hpp"
    30 #include "code/scopeDesc.hpp"
    31 #include "interpreter/bytecode.hpp"
    32 #include "interpreter/interpreter.hpp"
    33 #include "interpreter/oopMapCache.hpp"
    34 #include "memory/allocation.inline.hpp"
    35 #include "memory/oopFactory.hpp"
    36 #include "memory/resourceArea.hpp"
    37 #include "oops/methodOop.hpp"
    38 #include "oops/oop.inline.hpp"
    39 #include "prims/jvmtiThreadState.hpp"
    40 #include "runtime/biasedLocking.hpp"
    41 #include "runtime/compilationPolicy.hpp"
    42 #include "runtime/deoptimization.hpp"
    43 #include "runtime/interfaceSupport.hpp"
    44 #include "runtime/sharedRuntime.hpp"
    45 #include "runtime/signature.hpp"
    46 #include "runtime/stubRoutines.hpp"
    47 #include "runtime/thread.hpp"
    48 #include "runtime/vframe.hpp"
    49 #include "runtime/vframeArray.hpp"
    50 #include "runtime/vframe_hp.hpp"
    51 #include "utilities/events.hpp"
    52 #include "utilities/xmlstream.hpp"
    53 #ifdef TARGET_ARCH_x86
    54 # include "vmreg_x86.inline.hpp"
    55 #endif
    56 #ifdef TARGET_ARCH_sparc
    57 # include "vmreg_sparc.inline.hpp"
    58 #endif
    59 #ifdef TARGET_ARCH_zero
    60 # include "vmreg_zero.inline.hpp"
    61 #endif
    62 #ifdef TARGET_ARCH_arm
    63 # include "vmreg_arm.inline.hpp"
    64 #endif
    65 #ifdef TARGET_ARCH_ppc
    66 # include "vmreg_ppc.inline.hpp"
    67 #endif
    68 #ifdef COMPILER2
    69 #ifdef TARGET_ARCH_MODEL_x86_32
    70 # include "adfiles/ad_x86_32.hpp"
    71 #endif
    72 #ifdef TARGET_ARCH_MODEL_x86_64
    73 # include "adfiles/ad_x86_64.hpp"
    74 #endif
    75 #ifdef TARGET_ARCH_MODEL_sparc
    76 # include "adfiles/ad_sparc.hpp"
    77 #endif
    78 #ifdef TARGET_ARCH_MODEL_zero
    79 # include "adfiles/ad_zero.hpp"
    80 #endif
    81 #ifdef TARGET_ARCH_MODEL_arm
    82 # include "adfiles/ad_arm.hpp"
    83 #endif
    84 #ifdef TARGET_ARCH_MODEL_ppc
    85 # include "adfiles/ad_ppc.hpp"
    86 #endif
    87 #endif
    89 bool DeoptimizationMarker::_is_active = false;
    91 Deoptimization::UnrollBlock::UnrollBlock(int  size_of_deoptimized_frame,
    92                                          int  caller_adjustment,
    93                                          int  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);
   105   _return_type               = return_type;
   106   _initial_fp                = 0;
   107   // PD (x86 only)
   108   _counter_temp              = 0;
   109   _unpack_kind               = 0;
   110   _sender_sp_temp            = 0;
   112   _total_frame_sizes         = size_of_frames();
   113 }
   116 Deoptimization::UnrollBlock::~UnrollBlock() {
   117   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
   118   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
   119   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
   120 }
   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 }
   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 }
   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 }
   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
   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();
   168   return fetch_unroll_info_helper(thread);
   169 JRT_END
   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) {
   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   //
   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);
   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());
   194   if (VerifyStack) {
   195     thread->validate_frame_layout();
   196   }
   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));
   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) {
   215     if (EliminateAllocations) {
   216       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
   217       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
   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           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
   237         }
   238       }
   239       bool reallocated = false;
   240       if (objects != NULL) {
   241         JRT_BLOCK
   242           reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
   243         JRT_END
   244       }
   245       if (reallocated) {
   246         reassign_fields(&deoptee, &map, objects);
   247 #ifndef PRODUCT
   248         if (TraceDeoptimization) {
   249           ttyLocker ttyl;
   250           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
   251           print_objects(objects);
   252         }
   253 #endif
   254       }
   255       if (save_oop_result) {
   256         // Restore result.
   257         deoptee.set_saved_oop_result(&map, return_value());
   258       }
   259     }
   260     if (EliminateLocks) {
   261 #ifndef PRODUCT
   262       bool first = true;
   263 #endif
   264       for (int i = 0; i < chunk->length(); i++) {
   265         compiledVFrame* cvf = chunk->at(i);
   266         assert (cvf->scope() != NULL,"expect only compiled java frames");
   267         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
   268         if (monitors->is_nonempty()) {
   269           relock_objects(monitors, thread);
   270 #ifndef PRODUCT
   271           if (TraceDeoptimization) {
   272             ttyLocker ttyl;
   273             for (int j = 0; j < monitors->length(); j++) {
   274               MonitorInfo* mi = monitors->at(j);
   275               if (mi->eliminated()) {
   276                 if (first) {
   277                   first = false;
   278                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
   279                 }
   280                 tty->print_cr("     object <" INTPTR_FORMAT "> locked", mi->owner());
   281               }
   282             }
   283           }
   284 #endif
   285         }
   286       }
   287     }
   288   }
   289 #endif // COMPILER2
   290   // Ensure that no safepoint is taken after pointers have been stored
   291   // in fields of rematerialized objects.  If a safepoint occurs from here on
   292   // out the java state residing in the vframeArray will be missed.
   293   No_Safepoint_Verifier no_safepoint;
   295   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
   297   assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
   298   thread->set_vframe_array_head(array);
   300   // Now that the vframeArray has been created if we have any deferred local writes
   301   // added by jvmti then we can free up that structure as the data is now in the
   302   // vframeArray
   304   if (thread->deferred_locals() != NULL) {
   305     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
   306     int i = 0;
   307     do {
   308       // Because of inlining we could have multiple vframes for a single frame
   309       // and several of the vframes could have deferred writes. Find them all.
   310       if (list->at(i)->id() == array->original().id()) {
   311         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
   312         list->remove_at(i);
   313         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
   314         delete dlv;
   315       } else {
   316         i++;
   317       }
   318     } while ( i < list->length() );
   319     if (list->length() == 0) {
   320       thread->set_deferred_locals(NULL);
   321       // free the list and elements back to C heap.
   322       delete list;
   323     }
   325   }
   327 #ifndef SHARK
   328   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
   329   CodeBlob* cb = stub_frame.cb();
   330   // Verify we have the right vframeArray
   331   assert(cb->frame_size() >= 0, "Unexpected frame size");
   332   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
   334   // If the deopt call site is a MethodHandle invoke call site we have
   335   // to adjust the unpack_sp.
   336   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
   337   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
   338     unpack_sp = deoptee.unextended_sp();
   340 #ifdef ASSERT
   341   assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
   342   Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
   343 #endif
   344 #else
   345   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
   346 #endif // !SHARK
   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");
   358   int number_of_frames = array->frames();
   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);
   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);
   365   int callee_parameters = 0;
   366   int callee_locals = 0;
   367   int popframe_extra_args = 0;
   368   // Create an interpreter return address for the stub to use as its return
   369   // address so the skeletal frames are perfectly walkable
   370   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
   372   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
   373   // activation be put back on the expression stack of the caller for reexecution
   374   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
   375     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
   376   }
   378   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
   379   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
   380   // than simply use array->sender.pc(). This requires us to walk the current set of frames
   381   //
   382   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
   383   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
   385   // It's possible that the number of paramters at the call site is
   386   // different than number of arguments in the callee when method
   387   // handles are used.  If the caller is interpreted get the real
   388   // value so that the proper amount of space can be added to it's
   389   // frame.
   390   int caller_actual_parameters = callee_parameters;
   391   if (deopt_sender.is_interpreted_frame()) {
   392     methodHandle method = deopt_sender.interpreter_frame_method();
   393     Bytecode_invoke cur = Bytecode_invoke_check(method,
   394                                                 deopt_sender.interpreter_frame_bci());
   395     Symbol* signature = method->constants()->signature_ref_at(cur.index());
   396     ArgumentSizeComputer asc(signature);
   397     caller_actual_parameters = asc.size() + (cur.has_receiver() ? 1 : 0);
   398   }
   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   for (int index = 0; index < array->frames(); index++ ) {
   415     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
   416     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
   417     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
   418     int caller_parms = callee_parameters;
   419     if (index == array->frames() - 1) {
   420       // Use the value from the interpreted caller
   421       caller_parms = caller_actual_parameters;
   422     }
   423     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(caller_parms,
   424                                                                                                     callee_parameters,
   425                                                                                                     callee_locals,
   426                                                                                                     index == 0,
   427                                                                                                     popframe_extra_args);
   428     // This pc doesn't have to be perfect just good enough to identify the frame
   429     // as interpreted so the skeleton frame will be walkable
   430     // The correct pc will be set when the skeleton frame is completely filled out
   431     // The final pc we store in the loop is wrong and will be overwritten below
   432     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
   434     callee_parameters = array->element(index)->method()->size_of_parameters();
   435     callee_locals = array->element(index)->method()->max_locals();
   436     popframe_extra_args = 0;
   437   }
   439   // Compute whether the root vframe returns a float or double value.
   440   BasicType return_type;
   441   {
   442     HandleMark hm;
   443     methodHandle method(thread, array->element(0)->method());
   444     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
   445     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
   446   }
   448   // Compute information for handling adapters and adjusting the frame size of the caller.
   449   int caller_adjustment = 0;
   451   // Compute the amount the oldest interpreter frame will have to adjust
   452   // its caller's stack by. If the caller is a compiled frame then
   453   // we pretend that the callee has no parameters so that the
   454   // extension counts for the full amount of locals and not just
   455   // locals-parms. This is because without a c2i adapter the parm
   456   // area as created by the compiled frame will not be usable by
   457   // the interpreter. (Depending on the calling convention there
   458   // may not even be enough space).
   460   // QQQ I'd rather see this pushed down into last_frame_adjust
   461   // and have it take the sender (aka caller).
   463   if (deopt_sender.is_compiled_frame()) {
   464     caller_adjustment = last_frame_adjust(0, callee_locals);
   465   } else if (callee_locals > caller_actual_parameters) {
   466     // The caller frame may need extending to accommodate
   467     // non-parameter locals of the first unpacked interpreted frame.
   468     // Compute that adjustment.
   469     caller_adjustment = last_frame_adjust(caller_actual_parameters, callee_locals);
   470   }
   472   // If the sender is deoptimized the we must retrieve the address of the handler
   473   // since the frame will "magically" show the original pc before the deopt
   474   // and we'd undo the deopt.
   476   frame_pcs[0] = deopt_sender.raw_pc();
   478 #ifndef SHARK
   479   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
   480 #endif // SHARK
   482   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
   483                                       caller_adjustment * BytesPerWord,
   484                                       caller_actual_parameters,
   485                                       number_of_frames,
   486                                       frame_sizes,
   487                                       frame_pcs,
   488                                       return_type);
   489   // On some platforms, we need a way to pass fp to the unpacking code
   490   // so the skeletal frames come out correct.
   491   info->set_initial_fp((intptr_t) array->sender().fp());
   493   if (array->frames() > 1) {
   494     if (VerifyStack && TraceDeoptimization) {
   495       tty->print_cr("Deoptimizing method containing inlining");
   496     }
   497   }
   499   array->set_unroll_block(info);
   500   return info;
   501 }
   503 // Called to cleanup deoptimization data structures in normal case
   504 // after unpacking to stack and when stack overflow error occurs
   505 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
   506                                         vframeArray *array) {
   508   // Get array if coming from exception
   509   if (array == NULL) {
   510     array = thread->vframe_array_head();
   511   }
   512   thread->set_vframe_array_head(NULL);
   514   // Free the previous UnrollBlock
   515   vframeArray* old_array = thread->vframe_array_last();
   516   thread->set_vframe_array_last(array);
   518   if (old_array != NULL) {
   519     UnrollBlock* old_info = old_array->unroll_block();
   520     old_array->set_unroll_block(NULL);
   521     delete old_info;
   522     delete old_array;
   523   }
   525   // Deallocate any resource creating in this routine and any ResourceObjs allocated
   526   // inside the vframeArray (StackValueCollections)
   528   delete thread->deopt_mark();
   529   thread->set_deopt_mark(NULL);
   530   thread->set_deopt_nmethod(NULL);
   533   if (JvmtiExport::can_pop_frame()) {
   534 #ifndef CC_INTERP
   535     // Regardless of whether we entered this routine with the pending
   536     // popframe condition bit set, we should always clear it now
   537     thread->clear_popframe_condition();
   538 #else
   539     // C++ interpeter will clear has_pending_popframe when it enters
   540     // with method_resume. For deopt_resume2 we clear it now.
   541     if (thread->popframe_forcing_deopt_reexecution())
   542         thread->clear_popframe_condition();
   543 #endif /* CC_INTERP */
   544   }
   546   // unpack_frames() is called at the end of the deoptimization handler
   547   // and (in C2) at the end of the uncommon trap handler. Note this fact
   548   // so that an asynchronous stack walker can work again. This counter is
   549   // incremented at the beginning of fetch_unroll_info() and (in C2) at
   550   // the beginning of uncommon_trap().
   551   thread->dec_in_deopt_handler();
   552 }
   555 // Return BasicType of value being returned
   556 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
   558   // We are already active int he special DeoptResourceMark any ResourceObj's we
   559   // allocate will be freed at the end of the routine.
   561   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
   562   // but makes the entry a little slower. There is however a little dance we have to
   563   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
   564   ResetNoHandleMark rnhm; // No-op in release/product versions
   565   HandleMark hm;
   567   frame stub_frame = thread->last_frame();
   569   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
   570   // must point to the vframeArray for the unpack frame.
   571   vframeArray* array = thread->vframe_array_head();
   573 #ifndef PRODUCT
   574   if (TraceDeoptimization) {
   575     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
   576   }
   577 #endif
   579   UnrollBlock* info = array->unroll_block();
   581   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
   582   array->unpack_to_stack(stub_frame, exec_mode, info->caller_actual_parameters());
   584   BasicType bt = info->return_type();
   586   // If we have an exception pending, claim that the return type is an oop
   587   // so the deopt_blob does not overwrite the exception_oop.
   589   if (exec_mode == Unpack_exception)
   590     bt = T_OBJECT;
   592   // Cleanup thread deopt data
   593   cleanup_deopt_info(thread, array);
   595 #ifndef PRODUCT
   596   if (VerifyStack) {
   597     ResourceMark res_mark;
   599     thread->validate_frame_layout();
   601     // Verify that the just-unpacked frames match the interpreter's
   602     // notions of expression stack and locals
   603     vframeArray* cur_array = thread->vframe_array_last();
   604     RegisterMap rm(thread, false);
   605     rm.set_include_argument_oops(false);
   606     bool is_top_frame = true;
   607     int callee_size_of_parameters = 0;
   608     int callee_max_locals = 0;
   609     for (int i = 0; i < cur_array->frames(); i++) {
   610       vframeArrayElement* el = cur_array->element(i);
   611       frame* iframe = el->iframe();
   612       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
   614       // Get the oop map for this bci
   615       InterpreterOopMap mask;
   616       int cur_invoke_parameter_size = 0;
   617       bool try_next_mask = false;
   618       int next_mask_expression_stack_size = -1;
   619       int top_frame_expression_stack_adjustment = 0;
   620       methodHandle mh(thread, iframe->interpreter_frame_method());
   621       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
   622       BytecodeStream str(mh);
   623       str.set_start(iframe->interpreter_frame_bci());
   624       int max_bci = mh->code_size();
   625       // Get to the next bytecode if possible
   626       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
   627       // Check to see if we can grab the number of outgoing arguments
   628       // at an uncommon trap for an invoke (where the compiler
   629       // generates debug info before the invoke has executed)
   630       Bytecodes::Code cur_code = str.next();
   631       if (cur_code == Bytecodes::_invokevirtual ||
   632           cur_code == Bytecodes::_invokespecial ||
   633           cur_code == Bytecodes::_invokestatic  ||
   634           cur_code == Bytecodes::_invokeinterface) {
   635         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
   636         Symbol* signature = invoke.signature();
   637         ArgumentSizeComputer asc(signature);
   638         cur_invoke_parameter_size = asc.size();
   639         if (cur_code != Bytecodes::_invokestatic) {
   640           // Add in receiver
   641           ++cur_invoke_parameter_size;
   642         }
   643       }
   644       if (str.bci() < max_bci) {
   645         Bytecodes::Code bc = str.next();
   646         if (bc >= 0) {
   647           // The interpreter oop map generator reports results before
   648           // the current bytecode has executed except in the case of
   649           // calls. It seems to be hard to tell whether the compiler
   650           // has emitted debug information matching the "state before"
   651           // a given bytecode or the state after, so we try both
   652           switch (cur_code) {
   653             case Bytecodes::_invokevirtual:
   654             case Bytecodes::_invokespecial:
   655             case Bytecodes::_invokestatic:
   656             case Bytecodes::_invokeinterface:
   657             case Bytecodes::_athrow:
   658               break;
   659             default: {
   660               InterpreterOopMap next_mask;
   661               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
   662               next_mask_expression_stack_size = next_mask.expression_stack_size();
   663               // Need to subtract off the size of the result type of
   664               // the bytecode because this is not described in the
   665               // debug info but returned to the interpreter in the TOS
   666               // caching register
   667               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
   668               if (bytecode_result_type != T_ILLEGAL) {
   669                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
   670               }
   671               assert(top_frame_expression_stack_adjustment >= 0, "");
   672               try_next_mask = true;
   673               break;
   674             }
   675           }
   676         }
   677       }
   679       // Verify stack depth and oops in frame
   680       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
   681       if (!(
   682             /* SPARC */
   683             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
   684             /* x86 */
   685             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
   686             (try_next_mask &&
   687              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
   688                                                                     top_frame_expression_stack_adjustment))) ||
   689             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
   690             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
   691              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
   692             )) {
   693         ttyLocker ttyl;
   695         // Print out some information that will help us debug the problem
   696         tty->print_cr("Wrong number of expression stack elements during deoptimization");
   697         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
   698         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
   699                       iframe->interpreter_frame_expression_stack_size());
   700         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
   701         tty->print_cr("  try_next_mask = %d", try_next_mask);
   702         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
   703         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
   704         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
   705         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
   706         tty->print_cr("  exec_mode = %d", exec_mode);
   707         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
   708         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
   709         tty->print_cr("  Interpreted frames:");
   710         for (int k = 0; k < cur_array->frames(); k++) {
   711           vframeArrayElement* el = cur_array->element(k);
   712           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
   713         }
   714         cur_array->print_on_2(tty);
   715         guarantee(false, "wrong number of expression stack elements during deopt");
   716       }
   717       VerifyOopClosure verify;
   718       iframe->oops_interpreted_do(&verify, &rm, false);
   719       callee_size_of_parameters = mh->size_of_parameters();
   720       callee_max_locals = mh->max_locals();
   721       is_top_frame = false;
   722     }
   723   }
   724 #endif /* !PRODUCT */
   727   return bt;
   728 JRT_END
   731 int Deoptimization::deoptimize_dependents() {
   732   Threads::deoptimized_wrt_marked_nmethods();
   733   return 0;
   734 }
   737 #ifdef COMPILER2
   738 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
   739   Handle pending_exception(thread->pending_exception());
   740   const char* exception_file = thread->exception_file();
   741   int exception_line = thread->exception_line();
   742   thread->clear_pending_exception();
   744   for (int i = 0; i < objects->length(); i++) {
   745     assert(objects->at(i)->is_object(), "invalid debug information");
   746     ObjectValue* sv = (ObjectValue*) objects->at(i);
   748     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   749     oop obj = NULL;
   751     if (k->oop_is_instance()) {
   752       instanceKlass* ik = instanceKlass::cast(k());
   753       obj = ik->allocate_instance(CHECK_(false));
   754     } else if (k->oop_is_typeArray()) {
   755       typeArrayKlass* ak = typeArrayKlass::cast(k());
   756       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
   757       int len = sv->field_size() / type2size[ak->element_type()];
   758       obj = ak->allocate(len, CHECK_(false));
   759     } else if (k->oop_is_objArray()) {
   760       objArrayKlass* ak = objArrayKlass::cast(k());
   761       obj = ak->allocate(sv->field_size(), CHECK_(false));
   762     }
   764     assert(obj != NULL, "allocation failed");
   765     assert(sv->value().is_null(), "redundant reallocation");
   766     sv->set_value(obj);
   767   }
   769   if (pending_exception.not_null()) {
   770     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
   771   }
   773   return true;
   774 }
   776 // This assumes that the fields are stored in ObjectValue in the same order
   777 // they are yielded by do_nonstatic_fields.
   778 class FieldReassigner: public FieldClosure {
   779   frame* _fr;
   780   RegisterMap* _reg_map;
   781   ObjectValue* _sv;
   782   instanceKlass* _ik;
   783   oop _obj;
   785   int _i;
   786 public:
   787   FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
   788     _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
   790   int i() const { return _i; }
   793   void do_field(fieldDescriptor* fd) {
   794     intptr_t val;
   795     StackValue* value =
   796       StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
   797     int offset = fd->offset();
   798     switch (fd->field_type()) {
   799     case T_OBJECT: case T_ARRAY:
   800       assert(value->type() == T_OBJECT, "Agreement.");
   801       _obj->obj_field_put(offset, value->get_obj()());
   802       break;
   804     case T_LONG: case T_DOUBLE: {
   805       assert(value->type() == T_INT, "Agreement.");
   806       StackValue* low =
   807         StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
   808 #ifdef _LP64
   809       jlong res = (jlong)low->get_int();
   810 #else
   811 #ifdef SPARC
   812       // For SPARC we have to swap high and low words.
   813       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
   814 #else
   815       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
   816 #endif //SPARC
   817 #endif
   818       _obj->long_field_put(offset, res);
   819       break;
   820     }
   821     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
   822     case T_INT: case T_FLOAT: // 4 bytes.
   823       assert(value->type() == T_INT, "Agreement.");
   824       val = value->get_int();
   825       _obj->int_field_put(offset, (jint)*((jint*)&val));
   826       break;
   828     case T_SHORT: case T_CHAR: // 2 bytes
   829       assert(value->type() == T_INT, "Agreement.");
   830       val = value->get_int();
   831       _obj->short_field_put(offset, (jshort)*((jint*)&val));
   832       break;
   834     case T_BOOLEAN: case T_BYTE: // 1 byte
   835       assert(value->type() == T_INT, "Agreement.");
   836       val = value->get_int();
   837       _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
   838       break;
   840     default:
   841       ShouldNotReachHere();
   842     }
   843     _i++;
   844   }
   845 };
   847 // restore elements of an eliminated type array
   848 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
   849   int index = 0;
   850   intptr_t val;
   852   for (int i = 0; i < sv->field_size(); i++) {
   853     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
   854     switch(type) {
   855     case T_LONG: case T_DOUBLE: {
   856       assert(value->type() == T_INT, "Agreement.");
   857       StackValue* low =
   858         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
   859 #ifdef _LP64
   860       jlong res = (jlong)low->get_int();
   861 #else
   862 #ifdef SPARC
   863       // For SPARC we have to swap high and low words.
   864       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
   865 #else
   866       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
   867 #endif //SPARC
   868 #endif
   869       obj->long_at_put(index, res);
   870       break;
   871     }
   873     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
   874     case T_INT: case T_FLOAT: // 4 bytes.
   875       assert(value->type() == T_INT, "Agreement.");
   876       val = value->get_int();
   877       obj->int_at_put(index, (jint)*((jint*)&val));
   878       break;
   880     case T_SHORT: case T_CHAR: // 2 bytes
   881       assert(value->type() == T_INT, "Agreement.");
   882       val = value->get_int();
   883       obj->short_at_put(index, (jshort)*((jint*)&val));
   884       break;
   886     case T_BOOLEAN: case T_BYTE: // 1 byte
   887       assert(value->type() == T_INT, "Agreement.");
   888       val = value->get_int();
   889       obj->bool_at_put(index, (jboolean)*((jint*)&val));
   890       break;
   892       default:
   893         ShouldNotReachHere();
   894     }
   895     index++;
   896   }
   897 }
   900 // restore fields of an eliminated object array
   901 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
   902   for (int i = 0; i < sv->field_size(); i++) {
   903     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
   904     assert(value->type() == T_OBJECT, "object element expected");
   905     obj->obj_at_put(i, value->get_obj()());
   906   }
   907 }
   910 // restore fields of all eliminated objects and arrays
   911 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
   912   for (int i = 0; i < objects->length(); i++) {
   913     ObjectValue* sv = (ObjectValue*) objects->at(i);
   914     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   915     Handle obj = sv->value();
   916     assert(obj.not_null(), "reallocation was missed");
   918     if (k->oop_is_instance()) {
   919       instanceKlass* ik = instanceKlass::cast(k());
   920       FieldReassigner reassign(fr, reg_map, sv, obj());
   921       ik->do_nonstatic_fields(&reassign);
   922     } else if (k->oop_is_typeArray()) {
   923       typeArrayKlass* ak = typeArrayKlass::cast(k());
   924       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
   925     } else if (k->oop_is_objArray()) {
   926       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
   927     }
   928   }
   929 }
   932 // relock objects for which synchronization was eliminated
   933 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
   934   for (int i = 0; i < monitors->length(); i++) {
   935     MonitorInfo* mon_info = monitors->at(i);
   936     if (mon_info->eliminated()) {
   937       assert(mon_info->owner() != NULL, "reallocation was missed");
   938       Handle obj = Handle(mon_info->owner());
   939       markOop mark = obj->mark();
   940       if (UseBiasedLocking && mark->has_bias_pattern()) {
   941         // New allocated objects may have the mark set to anonymously biased.
   942         // Also the deoptimized method may called methods with synchronization
   943         // where the thread-local object is bias locked to the current thread.
   944         assert(mark->is_biased_anonymously() ||
   945                mark->biased_locker() == thread, "should be locked to current thread");
   946         // Reset mark word to unbiased prototype.
   947         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
   948         obj->set_mark(unbiased_prototype);
   949       }
   950       BasicLock* lock = mon_info->lock();
   951       ObjectSynchronizer::slow_enter(obj, lock, thread);
   952     }
   953     assert(mon_info->owner()->is_locked(), "object must be locked now");
   954   }
   955 }
   958 #ifndef PRODUCT
   959 // print information about reallocated objects
   960 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
   961   fieldDescriptor fd;
   963   for (int i = 0; i < objects->length(); i++) {
   964     ObjectValue* sv = (ObjectValue*) objects->at(i);
   965     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   966     Handle obj = sv->value();
   968     tty->print("     object <" INTPTR_FORMAT "> of type ", sv->value()());
   969     k->as_klassOop()->print_value();
   970     tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
   971     tty->cr();
   973     if (Verbose) {
   974       k->oop_print_on(obj(), tty);
   975     }
   976   }
   977 }
   978 #endif
   979 #endif // COMPILER2
   981 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
   983 #ifndef PRODUCT
   984   if (TraceDeoptimization) {
   985     ttyLocker ttyl;
   986     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
   987     fr.print_on(tty);
   988     tty->print_cr("     Virtual frames (innermost first):");
   989     for (int index = 0; index < chunk->length(); index++) {
   990       compiledVFrame* vf = chunk->at(index);
   991       tty->print("       %2d - ", index);
   992       vf->print_value();
   993       int bci = chunk->at(index)->raw_bci();
   994       const char* code_name;
   995       if (bci == SynchronizationEntryBCI) {
   996         code_name = "sync entry";
   997       } else {
   998         Bytecodes::Code code = vf->method()->code_at(bci);
   999         code_name = Bytecodes::name(code);
  1001       tty->print(" - %s", code_name);
  1002       tty->print_cr(" @ bci %d ", bci);
  1003       if (Verbose) {
  1004         vf->print();
  1005         tty->cr();
  1009 #endif
  1011   // Register map for next frame (used for stack crawl).  We capture
  1012   // the state of the deopt'ing frame's caller.  Thus if we need to
  1013   // stuff a C2I adapter we can properly fill in the callee-save
  1014   // register locations.
  1015   frame caller = fr.sender(reg_map);
  1016   int frame_size = caller.sp() - fr.sp();
  1018   frame sender = caller;
  1020   // Since the Java thread being deoptimized will eventually adjust it's own stack,
  1021   // the vframeArray containing the unpacking information is allocated in the C heap.
  1022   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
  1023   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
  1025   // Compare the vframeArray to the collected vframes
  1026   assert(array->structural_compare(thread, chunk), "just checking");
  1027   Events::log("# vframes = %d", (intptr_t)chunk->length());
  1029 #ifndef PRODUCT
  1030   if (TraceDeoptimization) {
  1031     ttyLocker ttyl;
  1032     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, array);
  1034 #endif // PRODUCT
  1036   return array;
  1040 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
  1041   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
  1042   for (int i = 0; i < monitors->length(); i++) {
  1043     MonitorInfo* mon_info = monitors->at(i);
  1044     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
  1045       objects_to_revoke->append(Handle(mon_info->owner()));
  1051 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
  1052   if (!UseBiasedLocking) {
  1053     return;
  1056   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
  1058   // Unfortunately we don't have a RegisterMap available in most of
  1059   // the places we want to call this routine so we need to walk the
  1060   // stack again to update the register map.
  1061   if (map == NULL || !map->update_map()) {
  1062     StackFrameStream sfs(thread, true);
  1063     bool found = false;
  1064     while (!found && !sfs.is_done()) {
  1065       frame* cur = sfs.current();
  1066       sfs.next();
  1067       found = cur->id() == fr.id();
  1069     assert(found, "frame to be deoptimized not found on target thread's stack");
  1070     map = sfs.register_map();
  1073   vframe* vf = vframe::new_vframe(&fr, map, thread);
  1074   compiledVFrame* cvf = compiledVFrame::cast(vf);
  1075   // Revoke monitors' biases in all scopes
  1076   while (!cvf->is_top()) {
  1077     collect_monitors(cvf, objects_to_revoke);
  1078     cvf = compiledVFrame::cast(cvf->sender());
  1080   collect_monitors(cvf, objects_to_revoke);
  1082   if (SafepointSynchronize::is_at_safepoint()) {
  1083     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
  1084   } else {
  1085     BiasedLocking::revoke(objects_to_revoke);
  1090 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
  1091   if (!UseBiasedLocking) {
  1092     return;
  1095   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
  1096   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
  1097   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
  1098     if (jt->has_last_Java_frame()) {
  1099       StackFrameStream sfs(jt, true);
  1100       while (!sfs.is_done()) {
  1101         frame* cur = sfs.current();
  1102         if (cb->contains(cur->pc())) {
  1103           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
  1104           compiledVFrame* cvf = compiledVFrame::cast(vf);
  1105           // Revoke monitors' biases in all scopes
  1106           while (!cvf->is_top()) {
  1107             collect_monitors(cvf, objects_to_revoke);
  1108             cvf = compiledVFrame::cast(cvf->sender());
  1110           collect_monitors(cvf, objects_to_revoke);
  1112         sfs.next();
  1116   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
  1120 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
  1121   assert(fr.can_be_deoptimized(), "checking frame type");
  1123   gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
  1125   EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
  1127   // Patch the nmethod so that when execution returns to it we will
  1128   // deopt the execution state and return to the interpreter.
  1129   fr.deoptimize(thread);
  1132 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
  1133   // Deoptimize only if the frame comes from compile code.
  1134   // Do not deoptimize the frame which is already patched
  1135   // during the execution of the loops below.
  1136   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
  1137     return;
  1139   ResourceMark rm;
  1140   DeoptimizationMarker dm;
  1141   if (UseBiasedLocking) {
  1142     revoke_biases_of_monitors(thread, fr, map);
  1144   deoptimize_single_frame(thread, fr);
  1149 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
  1150   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
  1151          "can only deoptimize other thread at a safepoint");
  1152   // Compute frame and register map based on thread and sp.
  1153   RegisterMap reg_map(thread, UseBiasedLocking);
  1154   frame fr = thread->last_frame();
  1155   while (fr.id() != id) {
  1156     fr = fr.sender(&reg_map);
  1158   deoptimize(thread, fr, &reg_map);
  1162 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
  1163   if (thread == Thread::current()) {
  1164     Deoptimization::deoptimize_frame_internal(thread, id);
  1165   } else {
  1166     VM_DeoptimizeFrame deopt(thread, id);
  1167     VMThread::execute(&deopt);
  1172 // JVMTI PopFrame support
  1173 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
  1175   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
  1177 JRT_END
  1180 #if defined(COMPILER2) || defined(SHARK)
  1181 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
  1182   // in case of an unresolved klass entry, load the class.
  1183   if (constant_pool->tag_at(index).is_unresolved_klass()) {
  1184     klassOop tk = constant_pool->klass_at(index, CHECK);
  1185     return;
  1188   if (!constant_pool->tag_at(index).is_symbol()) return;
  1190   Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
  1191   Symbol*  symbol  = constant_pool->symbol_at(index);
  1193   // class name?
  1194   if (symbol->byte_at(0) != '(') {
  1195     Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
  1196     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
  1197     return;
  1200   // then it must be a signature!
  1201   ResourceMark rm(THREAD);
  1202   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
  1203     if (ss.is_object()) {
  1204       Symbol* class_name = ss.as_symbol(CHECK);
  1205       Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
  1206       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
  1212 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
  1213   EXCEPTION_MARK;
  1214   load_class_by_index(constant_pool, index, THREAD);
  1215   if (HAS_PENDING_EXCEPTION) {
  1216     // Exception happened during classloading. We ignore the exception here, since it
  1217     // is going to be rethrown since the current activation is going to be deoptimzied and
  1218     // the interpreter will re-execute the bytecode.
  1219     CLEAR_PENDING_EXCEPTION;
  1223 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
  1224   HandleMark hm;
  1226   // uncommon_trap() is called at the beginning of the uncommon trap
  1227   // handler. Note this fact before we start generating temporary frames
  1228   // that can confuse an asynchronous stack walker. This counter is
  1229   // decremented at the end of unpack_frames().
  1230   thread->inc_in_deopt_handler();
  1232   // We need to update the map if we have biased locking.
  1233   RegisterMap reg_map(thread, UseBiasedLocking);
  1234   frame stub_frame = thread->last_frame();
  1235   frame fr = stub_frame.sender(&reg_map);
  1236   // Make sure the calling nmethod is not getting deoptimized and removed
  1237   // before we are done with it.
  1238   nmethodLocker nl(fr.pc());
  1241     ResourceMark rm;
  1243     // Revoke biases of any monitors in the frame to ensure we can migrate them
  1244     revoke_biases_of_monitors(thread, fr, &reg_map);
  1246     DeoptReason reason = trap_request_reason(trap_request);
  1247     DeoptAction action = trap_request_action(trap_request);
  1248     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
  1250     Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
  1251     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
  1252     compiledVFrame* cvf = compiledVFrame::cast(vf);
  1254     nmethod* nm = cvf->code();
  1256     ScopeDesc*      trap_scope  = cvf->scope();
  1257     methodHandle    trap_method = trap_scope->method();
  1258     int             trap_bci    = trap_scope->bci();
  1259     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
  1261     // Record this event in the histogram.
  1262     gather_statistics(reason, action, trap_bc);
  1264     // Ensure that we can record deopt. history:
  1265     bool create_if_missing = ProfileTraps;
  1267     methodDataHandle trap_mdo
  1268       (THREAD, get_method_data(thread, trap_method, create_if_missing));
  1270     // Print a bunch of diagnostics, if requested.
  1271     if (TraceDeoptimization || LogCompilation) {
  1272       ResourceMark rm;
  1273       ttyLocker ttyl;
  1274       char buf[100];
  1275       if (xtty != NULL) {
  1276         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
  1277                          os::current_thread_id(),
  1278                          format_trap_request(buf, sizeof(buf), trap_request));
  1279         nm->log_identity(xtty);
  1281       Symbol* class_name = NULL;
  1282       bool unresolved = false;
  1283       if (unloaded_class_index >= 0) {
  1284         constantPoolHandle constants (THREAD, trap_method->constants());
  1285         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
  1286           class_name = constants->klass_name_at(unloaded_class_index);
  1287           unresolved = true;
  1288           if (xtty != NULL)
  1289             xtty->print(" unresolved='1'");
  1290         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
  1291           class_name = constants->symbol_at(unloaded_class_index);
  1293         if (xtty != NULL)
  1294           xtty->name(class_name);
  1296       if (xtty != NULL && trap_mdo.not_null()) {
  1297         // Dump the relevant MDO state.
  1298         // This is the deopt count for the current reason, any previous
  1299         // reasons or recompiles seen at this point.
  1300         int dcnt = trap_mdo->trap_count(reason);
  1301         if (dcnt != 0)
  1302           xtty->print(" count='%d'", dcnt);
  1303         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
  1304         int dos = (pdata == NULL)? 0: pdata->trap_state();
  1305         if (dos != 0) {
  1306           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
  1307           if (trap_state_is_recompiled(dos)) {
  1308             int recnt2 = trap_mdo->overflow_recompile_count();
  1309             if (recnt2 != 0)
  1310               xtty->print(" recompiles2='%d'", recnt2);
  1314       if (xtty != NULL) {
  1315         xtty->stamp();
  1316         xtty->end_head();
  1318       if (TraceDeoptimization) {  // make noise on the tty
  1319         tty->print("Uncommon trap occurred in");
  1320         nm->method()->print_short_name(tty);
  1321         tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
  1322                    fr.pc(),
  1323                    (int) os::current_thread_id(),
  1324                    trap_reason_name(reason),
  1325                    trap_action_name(action),
  1326                    unloaded_class_index);
  1327         if (class_name != NULL) {
  1328           tty->print(unresolved ? " unresolved class: " : " symbol: ");
  1329           class_name->print_symbol_on(tty);
  1331         tty->cr();
  1333       if (xtty != NULL) {
  1334         // Log the precise location of the trap.
  1335         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
  1336           xtty->begin_elem("jvms bci='%d'", sd->bci());
  1337           xtty->method(sd->method());
  1338           xtty->end_elem();
  1339           if (sd->is_top())  break;
  1341         xtty->tail("uncommon_trap");
  1344     // (End diagnostic printout.)
  1346     // Load class if necessary
  1347     if (unloaded_class_index >= 0) {
  1348       constantPoolHandle constants(THREAD, trap_method->constants());
  1349       load_class_by_index(constants, unloaded_class_index);
  1352     // Flush the nmethod if necessary and desirable.
  1353     //
  1354     // We need to avoid situations where we are re-flushing the nmethod
  1355     // because of a hot deoptimization site.  Repeated flushes at the same
  1356     // point need to be detected by the compiler and avoided.  If the compiler
  1357     // cannot avoid them (or has a bug and "refuses" to avoid them), this
  1358     // module must take measures to avoid an infinite cycle of recompilation
  1359     // and deoptimization.  There are several such measures:
  1360     //
  1361     //   1. If a recompilation is ordered a second time at some site X
  1362     //   and for the same reason R, the action is adjusted to 'reinterpret',
  1363     //   to give the interpreter time to exercise the method more thoroughly.
  1364     //   If this happens, the method's overflow_recompile_count is incremented.
  1365     //
  1366     //   2. If the compiler fails to reduce the deoptimization rate, then
  1367     //   the method's overflow_recompile_count will begin to exceed the set
  1368     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
  1369     //   is adjusted to 'make_not_compilable', and the method is abandoned
  1370     //   to the interpreter.  This is a performance hit for hot methods,
  1371     //   but is better than a disastrous infinite cycle of recompilations.
  1372     //   (Actually, only the method containing the site X is abandoned.)
  1373     //
  1374     //   3. In parallel with the previous measures, if the total number of
  1375     //   recompilations of a method exceeds the much larger set limit
  1376     //   PerMethodRecompilationCutoff, the method is abandoned.
  1377     //   This should only happen if the method is very large and has
  1378     //   many "lukewarm" deoptimizations.  The code which enforces this
  1379     //   limit is elsewhere (class nmethod, class methodOopDesc).
  1380     //
  1381     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
  1382     // to recompile at each bytecode independently of the per-BCI cutoff.
  1383     //
  1384     // The decision to update code is up to the compiler, and is encoded
  1385     // in the Action_xxx code.  If the compiler requests Action_none
  1386     // no trap state is changed, no compiled code is changed, and the
  1387     // computation suffers along in the interpreter.
  1388     //
  1389     // The other action codes specify various tactics for decompilation
  1390     // and recompilation.  Action_maybe_recompile is the loosest, and
  1391     // allows the compiled code to stay around until enough traps are seen,
  1392     // and until the compiler gets around to recompiling the trapping method.
  1393     //
  1394     // The other actions cause immediate removal of the present code.
  1396     bool update_trap_state = true;
  1397     bool make_not_entrant = false;
  1398     bool make_not_compilable = false;
  1399     bool reprofile = false;
  1400     switch (action) {
  1401     case Action_none:
  1402       // Keep the old code.
  1403       update_trap_state = false;
  1404       break;
  1405     case Action_maybe_recompile:
  1406       // Do not need to invalidate the present code, but we can
  1407       // initiate another
  1408       // Start compiler without (necessarily) invalidating the nmethod.
  1409       // The system will tolerate the old code, but new code should be
  1410       // generated when possible.
  1411       break;
  1412     case Action_reinterpret:
  1413       // Go back into the interpreter for a while, and then consider
  1414       // recompiling form scratch.
  1415       make_not_entrant = true;
  1416       // Reset invocation counter for outer most method.
  1417       // This will allow the interpreter to exercise the bytecodes
  1418       // for a while before recompiling.
  1419       // By contrast, Action_make_not_entrant is immediate.
  1420       //
  1421       // Note that the compiler will track null_check, null_assert,
  1422       // range_check, and class_check events and log them as if they
  1423       // had been traps taken from compiled code.  This will update
  1424       // the MDO trap history so that the next compilation will
  1425       // properly detect hot trap sites.
  1426       reprofile = true;
  1427       break;
  1428     case Action_make_not_entrant:
  1429       // Request immediate recompilation, and get rid of the old code.
  1430       // Make them not entrant, so next time they are called they get
  1431       // recompiled.  Unloaded classes are loaded now so recompile before next
  1432       // time they are called.  Same for uninitialized.  The interpreter will
  1433       // link the missing class, if any.
  1434       make_not_entrant = true;
  1435       break;
  1436     case Action_make_not_compilable:
  1437       // Give up on compiling this method at all.
  1438       make_not_entrant = true;
  1439       make_not_compilable = true;
  1440       break;
  1441     default:
  1442       ShouldNotReachHere();
  1445     // Setting +ProfileTraps fixes the following, on all platforms:
  1446     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
  1447     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
  1448     // recompile relies on a methodDataOop to record heroic opt failures.
  1450     // Whether the interpreter is producing MDO data or not, we also need
  1451     // to use the MDO to detect hot deoptimization points and control
  1452     // aggressive optimization.
  1453     bool inc_recompile_count = false;
  1454     ProfileData* pdata = NULL;
  1455     if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
  1456       assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
  1457       uint this_trap_count = 0;
  1458       bool maybe_prior_trap = false;
  1459       bool maybe_prior_recompile = false;
  1460       pdata = query_update_method_data(trap_mdo, trap_bci, reason,
  1461                                    //outputs:
  1462                                    this_trap_count,
  1463                                    maybe_prior_trap,
  1464                                    maybe_prior_recompile);
  1465       // Because the interpreter also counts null, div0, range, and class
  1466       // checks, these traps from compiled code are double-counted.
  1467       // This is harmless; it just means that the PerXTrapLimit values
  1468       // are in effect a little smaller than they look.
  1470       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
  1471       if (per_bc_reason != Reason_none) {
  1472         // Now take action based on the partially known per-BCI history.
  1473         if (maybe_prior_trap
  1474             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
  1475           // If there are too many traps at this BCI, force a recompile.
  1476           // This will allow the compiler to see the limit overflow, and
  1477           // take corrective action, if possible.  The compiler generally
  1478           // does not use the exact PerBytecodeTrapLimit value, but instead
  1479           // changes its tactics if it sees any traps at all.  This provides
  1480           // a little hysteresis, delaying a recompile until a trap happens
  1481           // several times.
  1482           //
  1483           // Actually, since there is only one bit of counter per BCI,
  1484           // the possible per-BCI counts are {0,1,(per-method count)}.
  1485           // This produces accurate results if in fact there is only
  1486           // one hot trap site, but begins to get fuzzy if there are
  1487           // many sites.  For example, if there are ten sites each
  1488           // trapping two or more times, they each get the blame for
  1489           // all of their traps.
  1490           make_not_entrant = true;
  1493         // Detect repeated recompilation at the same BCI, and enforce a limit.
  1494         if (make_not_entrant && maybe_prior_recompile) {
  1495           // More than one recompile at this point.
  1496           inc_recompile_count = maybe_prior_trap;
  1498       } else {
  1499         // For reasons which are not recorded per-bytecode, we simply
  1500         // force recompiles unconditionally.
  1501         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
  1502         make_not_entrant = true;
  1505       // Go back to the compiler if there are too many traps in this method.
  1506       if (this_trap_count >= (uint)PerMethodTrapLimit) {
  1507         // If there are too many traps in this method, force a recompile.
  1508         // This will allow the compiler to see the limit overflow, and
  1509         // take corrective action, if possible.
  1510         // (This condition is an unlikely backstop only, because the
  1511         // PerBytecodeTrapLimit is more likely to take effect first,
  1512         // if it is applicable.)
  1513         make_not_entrant = true;
  1516       // Here's more hysteresis:  If there has been a recompile at
  1517       // this trap point already, run the method in the interpreter
  1518       // for a while to exercise it more thoroughly.
  1519       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
  1520         reprofile = true;
  1525     // Take requested actions on the method:
  1527     // Recompile
  1528     if (make_not_entrant) {
  1529       if (!nm->make_not_entrant()) {
  1530         return; // the call did not change nmethod's state
  1533       if (pdata != NULL) {
  1534         // Record the recompilation event, if any.
  1535         int tstate0 = pdata->trap_state();
  1536         int tstate1 = trap_state_set_recompiled(tstate0, true);
  1537         if (tstate1 != tstate0)
  1538           pdata->set_trap_state(tstate1);
  1542     if (inc_recompile_count) {
  1543       trap_mdo->inc_overflow_recompile_count();
  1544       if ((uint)trap_mdo->overflow_recompile_count() >
  1545           (uint)PerBytecodeRecompilationCutoff) {
  1546         // Give up on the method containing the bad BCI.
  1547         if (trap_method() == nm->method()) {
  1548           make_not_compilable = true;
  1549         } else {
  1550           trap_method->set_not_compilable(CompLevel_full_optimization);
  1551           // But give grace to the enclosing nm->method().
  1556     // Reprofile
  1557     if (reprofile) {
  1558       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
  1561     // Give up compiling
  1562     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
  1563       assert(make_not_entrant, "consistent");
  1564       nm->method()->set_not_compilable(CompLevel_full_optimization);
  1567   } // Free marked resources
  1570 JRT_END
  1572 methodDataOop
  1573 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
  1574                                 bool create_if_missing) {
  1575   Thread* THREAD = thread;
  1576   methodDataOop mdo = m()->method_data();
  1577   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
  1578     // Build an MDO.  Ignore errors like OutOfMemory;
  1579     // that simply means we won't have an MDO to update.
  1580     methodOopDesc::build_interpreter_method_data(m, THREAD);
  1581     if (HAS_PENDING_EXCEPTION) {
  1582       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
  1583       CLEAR_PENDING_EXCEPTION;
  1585     mdo = m()->method_data();
  1587   return mdo;
  1590 ProfileData*
  1591 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
  1592                                          int trap_bci,
  1593                                          Deoptimization::DeoptReason reason,
  1594                                          //outputs:
  1595                                          uint& ret_this_trap_count,
  1596                                          bool& ret_maybe_prior_trap,
  1597                                          bool& ret_maybe_prior_recompile) {
  1598   uint prior_trap_count = trap_mdo->trap_count(reason);
  1599   uint this_trap_count  = trap_mdo->inc_trap_count(reason);
  1601   // If the runtime cannot find a place to store trap history,
  1602   // it is estimated based on the general condition of the method.
  1603   // If the method has ever been recompiled, or has ever incurred
  1604   // a trap with the present reason , then this BCI is assumed
  1605   // (pessimistically) to be the culprit.
  1606   bool maybe_prior_trap      = (prior_trap_count != 0);
  1607   bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
  1608   ProfileData* pdata = NULL;
  1611   // For reasons which are recorded per bytecode, we check per-BCI data.
  1612   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
  1613   if (per_bc_reason != Reason_none) {
  1614     // Find the profile data for this BCI.  If there isn't one,
  1615     // try to allocate one from the MDO's set of spares.
  1616     // This will let us detect a repeated trap at this point.
  1617     pdata = trap_mdo->allocate_bci_to_data(trap_bci);
  1619     if (pdata != NULL) {
  1620       // Query the trap state of this profile datum.
  1621       int tstate0 = pdata->trap_state();
  1622       if (!trap_state_has_reason(tstate0, per_bc_reason))
  1623         maybe_prior_trap = false;
  1624       if (!trap_state_is_recompiled(tstate0))
  1625         maybe_prior_recompile = false;
  1627       // Update the trap state of this profile datum.
  1628       int tstate1 = tstate0;
  1629       // Record the reason.
  1630       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
  1631       // Store the updated state on the MDO, for next time.
  1632       if (tstate1 != tstate0)
  1633         pdata->set_trap_state(tstate1);
  1634     } else {
  1635       if (LogCompilation && xtty != NULL) {
  1636         ttyLocker ttyl;
  1637         // Missing MDP?  Leave a small complaint in the log.
  1638         xtty->elem("missing_mdp bci='%d'", trap_bci);
  1643   // Return results:
  1644   ret_this_trap_count = this_trap_count;
  1645   ret_maybe_prior_trap = maybe_prior_trap;
  1646   ret_maybe_prior_recompile = maybe_prior_recompile;
  1647   return pdata;
  1650 void
  1651 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
  1652   ResourceMark rm;
  1653   // Ignored outputs:
  1654   uint ignore_this_trap_count;
  1655   bool ignore_maybe_prior_trap;
  1656   bool ignore_maybe_prior_recompile;
  1657   query_update_method_data(trap_mdo, trap_bci,
  1658                            (DeoptReason)reason,
  1659                            ignore_this_trap_count,
  1660                            ignore_maybe_prior_trap,
  1661                            ignore_maybe_prior_recompile);
  1664 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
  1666   // Still in Java no safepoints
  1668     // This enters VM and may safepoint
  1669     uncommon_trap_inner(thread, trap_request);
  1671   return fetch_unroll_info_helper(thread);
  1674 // Local derived constants.
  1675 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
  1676 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
  1677 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
  1679 //---------------------------trap_state_reason---------------------------------
  1680 Deoptimization::DeoptReason
  1681 Deoptimization::trap_state_reason(int trap_state) {
  1682   // This assert provides the link between the width of DataLayout::trap_bits
  1683   // and the encoding of "recorded" reasons.  It ensures there are enough
  1684   // bits to store all needed reasons in the per-BCI MDO profile.
  1685   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
  1686   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
  1687   trap_state -= recompile_bit;
  1688   if (trap_state == DS_REASON_MASK) {
  1689     return Reason_many;
  1690   } else {
  1691     assert((int)Reason_none == 0, "state=0 => Reason_none");
  1692     return (DeoptReason)trap_state;
  1695 //-------------------------trap_state_has_reason-------------------------------
  1696 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
  1697   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
  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 -1;  // true, unspecifically (bottom of state lattice)
  1703   } else if (trap_state == reason) {
  1704     return 1;   // true, definitely
  1705   } else if (trap_state == 0) {
  1706     return 0;   // false, definitely (top of state lattice)
  1707   } else {
  1708     return 0;   // false, definitely
  1711 //-------------------------trap_state_add_reason-------------------------------
  1712 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
  1713   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
  1714   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
  1715   trap_state -= recompile_bit;
  1716   if (trap_state == DS_REASON_MASK) {
  1717     return trap_state + recompile_bit;     // already at state lattice bottom
  1718   } else if (trap_state == reason) {
  1719     return trap_state + recompile_bit;     // the condition is already true
  1720   } else if (trap_state == 0) {
  1721     return reason + recompile_bit;          // no condition has yet been true
  1722   } else {
  1723     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
  1726 //-----------------------trap_state_is_recompiled------------------------------
  1727 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
  1728   return (trap_state & DS_RECOMPILE_BIT) != 0;
  1730 //-----------------------trap_state_set_recompiled-----------------------------
  1731 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
  1732   if (z)  return trap_state |  DS_RECOMPILE_BIT;
  1733   else    return trap_state & ~DS_RECOMPILE_BIT;
  1735 //---------------------------format_trap_state---------------------------------
  1736 // This is used for debugging and diagnostics, including hotspot.log output.
  1737 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
  1738                                               int trap_state) {
  1739   DeoptReason reason      = trap_state_reason(trap_state);
  1740   bool        recomp_flag = trap_state_is_recompiled(trap_state);
  1741   // Re-encode the state from its decoded components.
  1742   int decoded_state = 0;
  1743   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
  1744     decoded_state = trap_state_add_reason(decoded_state, reason);
  1745   if (recomp_flag)
  1746     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
  1747   // If the state re-encodes properly, format it symbolically.
  1748   // Because this routine is used for debugging and diagnostics,
  1749   // be robust even if the state is a strange value.
  1750   size_t len;
  1751   if (decoded_state != trap_state) {
  1752     // Random buggy state that doesn't decode??
  1753     len = jio_snprintf(buf, buflen, "#%d", trap_state);
  1754   } else {
  1755     len = jio_snprintf(buf, buflen, "%s%s",
  1756                        trap_reason_name(reason),
  1757                        recomp_flag ? " recompiled" : "");
  1759   if (len >= buflen)
  1760     buf[buflen-1] = '\0';
  1761   return buf;
  1765 //--------------------------------statics--------------------------------------
  1766 Deoptimization::DeoptAction Deoptimization::_unloaded_action
  1767   = Deoptimization::Action_reinterpret;
  1768 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
  1769   // Note:  Keep this in sync. with enum DeoptReason.
  1770   "none",
  1771   "null_check",
  1772   "null_assert",
  1773   "range_check",
  1774   "class_check",
  1775   "array_check",
  1776   "intrinsic",
  1777   "bimorphic",
  1778   "unloaded",
  1779   "uninitialized",
  1780   "unreached",
  1781   "unhandled",
  1782   "constraint",
  1783   "div0_check",
  1784   "age",
  1785   "predicate",
  1786   "loop_limit_check"
  1787 };
  1788 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
  1789   // Note:  Keep this in sync. with enum DeoptAction.
  1790   "none",
  1791   "maybe_recompile",
  1792   "reinterpret",
  1793   "make_not_entrant",
  1794   "make_not_compilable"
  1795 };
  1797 const char* Deoptimization::trap_reason_name(int reason) {
  1798   if (reason == Reason_many)  return "many";
  1799   if ((uint)reason < Reason_LIMIT)
  1800     return _trap_reason_name[reason];
  1801   static char buf[20];
  1802   sprintf(buf, "reason%d", reason);
  1803   return buf;
  1805 const char* Deoptimization::trap_action_name(int action) {
  1806   if ((uint)action < Action_LIMIT)
  1807     return _trap_action_name[action];
  1808   static char buf[20];
  1809   sprintf(buf, "action%d", action);
  1810   return buf;
  1813 // This is used for debugging and diagnostics, including hotspot.log output.
  1814 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
  1815                                                 int trap_request) {
  1816   jint unloaded_class_index = trap_request_index(trap_request);
  1817   const char* reason = trap_reason_name(trap_request_reason(trap_request));
  1818   const char* action = trap_action_name(trap_request_action(trap_request));
  1819   size_t len;
  1820   if (unloaded_class_index < 0) {
  1821     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
  1822                        reason, action);
  1823   } else {
  1824     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
  1825                        reason, action, unloaded_class_index);
  1827   if (len >= buflen)
  1828     buf[buflen-1] = '\0';
  1829   return buf;
  1832 juint Deoptimization::_deoptimization_hist
  1833         [Deoptimization::Reason_LIMIT]
  1834     [1 + Deoptimization::Action_LIMIT]
  1835         [Deoptimization::BC_CASE_LIMIT]
  1836   = {0};
  1838 enum {
  1839   LSB_BITS = 8,
  1840   LSB_MASK = right_n_bits(LSB_BITS)
  1841 };
  1843 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
  1844                                        Bytecodes::Code bc) {
  1845   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
  1846   assert(action >= 0 && action < Action_LIMIT, "oob");
  1847   _deoptimization_hist[Reason_none][0][0] += 1;  // total
  1848   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
  1849   juint* cases = _deoptimization_hist[reason][1+action];
  1850   juint* bc_counter_addr = NULL;
  1851   juint  bc_counter      = 0;
  1852   // Look for an unused counter, or an exact match to this BC.
  1853   if (bc != Bytecodes::_illegal) {
  1854     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
  1855       juint* counter_addr = &cases[bc_case];
  1856       juint  counter = *counter_addr;
  1857       if ((counter == 0 && bc_counter_addr == NULL)
  1858           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
  1859         // this counter is either free or is already devoted to this BC
  1860         bc_counter_addr = counter_addr;
  1861         bc_counter = counter | bc;
  1865   if (bc_counter_addr == NULL) {
  1866     // Overflow, or no given bytecode.
  1867     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
  1868     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
  1870   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
  1873 jint Deoptimization::total_deoptimization_count() {
  1874   return _deoptimization_hist[Reason_none][0][0];
  1877 jint Deoptimization::deoptimization_count(DeoptReason reason) {
  1878   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
  1879   return _deoptimization_hist[reason][0][0];
  1882 void Deoptimization::print_statistics() {
  1883   juint total = total_deoptimization_count();
  1884   juint account = total;
  1885   if (total != 0) {
  1886     ttyLocker ttyl;
  1887     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
  1888     tty->print_cr("Deoptimization traps recorded:");
  1889     #define PRINT_STAT_LINE(name, r) \
  1890       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
  1891     PRINT_STAT_LINE("total", total);
  1892     // For each non-zero entry in the histogram, print the reason,
  1893     // the action, and (if specifically known) the type of bytecode.
  1894     for (int reason = 0; reason < Reason_LIMIT; reason++) {
  1895       for (int action = 0; action < Action_LIMIT; action++) {
  1896         juint* cases = _deoptimization_hist[reason][1+action];
  1897         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
  1898           juint counter = cases[bc_case];
  1899           if (counter != 0) {
  1900             char name[1*K];
  1901             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
  1902             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
  1903               bc = Bytecodes::_illegal;
  1904             sprintf(name, "%s/%s/%s",
  1905                     trap_reason_name(reason),
  1906                     trap_action_name(action),
  1907                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
  1908             juint r = counter >> LSB_BITS;
  1909             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
  1910             account -= r;
  1915     if (account != 0) {
  1916       PRINT_STAT_LINE("unaccounted", account);
  1918     #undef PRINT_STAT_LINE
  1919     if (xtty != NULL)  xtty->tail("statistics");
  1922 #else // COMPILER2 || SHARK
  1925 // Stubs for C1 only system.
  1926 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
  1927   return false;
  1930 const char* Deoptimization::trap_reason_name(int reason) {
  1931   return "unknown";
  1934 void Deoptimization::print_statistics() {
  1935   // no output
  1938 void
  1939 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
  1940   // no udpate
  1943 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
  1944   return 0;
  1947 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
  1948                                        Bytecodes::Code bc) {
  1949   // no update
  1952 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
  1953                                               int trap_state) {
  1954   jio_snprintf(buf, buflen, "#%d", trap_state);
  1955   return buf;
  1958 #endif // COMPILER2 || SHARK

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