src/share/vm/runtime/deoptimization.cpp

Tue, 08 Feb 2011 09:11:37 -0800

author
mchung
date
Tue, 08 Feb 2011 09:11:37 -0800
changeset 2518
f36c9fe788b8
parent 2508
b92c45f2bc75
child 2620
4f148718983e
permissions
-rw-r--r--

7017673: Remove setting of the sun.jkernel.DownloadManager as a boot classloader hook
Reviewed-by: alanb, dcubed, 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  number_of_frames,
    94                                          intptr_t* frame_sizes,
    95                                          address* frame_pcs,
    96                                          BasicType return_type) {
    97   _size_of_deoptimized_frame = size_of_deoptimized_frame;
    98   _caller_adjustment         = caller_adjustment;
    99   _number_of_frames          = number_of_frames;
   100   _frame_sizes               = frame_sizes;
   101   _frame_pcs                 = frame_pcs;
   102   _register_block            = NEW_C_HEAP_ARRAY(intptr_t, RegisterMap::reg_count * 2);
   103   _return_type               = return_type;
   104   // PD (x86 only)
   105   _counter_temp              = 0;
   106   _initial_fp                = 0;
   107   _unpack_kind               = 0;
   108   _sender_sp_temp            = 0;
   110   _total_frame_sizes         = size_of_frames();
   111 }
   114 Deoptimization::UnrollBlock::~UnrollBlock() {
   115   FREE_C_HEAP_ARRAY(intptr_t, _frame_sizes);
   116   FREE_C_HEAP_ARRAY(intptr_t, _frame_pcs);
   117   FREE_C_HEAP_ARRAY(intptr_t, _register_block);
   118 }
   121 intptr_t* Deoptimization::UnrollBlock::value_addr_at(int register_number) const {
   122   assert(register_number < RegisterMap::reg_count, "checking register number");
   123   return &_register_block[register_number * 2];
   124 }
   128 int Deoptimization::UnrollBlock::size_of_frames() const {
   129   // Acount first for the adjustment of the initial frame
   130   int result = _caller_adjustment;
   131   for (int index = 0; index < number_of_frames(); index++) {
   132     result += frame_sizes()[index];
   133   }
   134   return result;
   135 }
   138 void Deoptimization::UnrollBlock::print() {
   139   ttyLocker ttyl;
   140   tty->print_cr("UnrollBlock");
   141   tty->print_cr("  size_of_deoptimized_frame = %d", _size_of_deoptimized_frame);
   142   tty->print(   "  frame_sizes: ");
   143   for (int index = 0; index < number_of_frames(); index++) {
   144     tty->print("%d ", frame_sizes()[index]);
   145   }
   146   tty->cr();
   147 }
   150 // In order to make fetch_unroll_info work properly with escape
   151 // analysis, The method was changed from JRT_LEAF to JRT_BLOCK_ENTRY and
   152 // ResetNoHandleMark and HandleMark were removed from it. The actual reallocation
   153 // of previously eliminated objects occurs in realloc_objects, which is
   154 // called from the method fetch_unroll_info_helper below.
   155 JRT_BLOCK_ENTRY(Deoptimization::UnrollBlock*, Deoptimization::fetch_unroll_info(JavaThread* thread))
   156   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
   157   // but makes the entry a little slower. There is however a little dance we have to
   158   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
   160   // fetch_unroll_info() is called at the beginning of the deoptimization
   161   // handler. Note this fact before we start generating temporary frames
   162   // that can confuse an asynchronous stack walker. This counter is
   163   // decremented at the end of unpack_frames().
   164   thread->inc_in_deopt_handler();
   166   return fetch_unroll_info_helper(thread);
   167 JRT_END
   170 // This is factored, since it is both called from a JRT_LEAF (deoptimization) and a JRT_ENTRY (uncommon_trap)
   171 Deoptimization::UnrollBlock* Deoptimization::fetch_unroll_info_helper(JavaThread* thread) {
   173   // Note: there is a safepoint safety issue here. No matter whether we enter
   174   // via vanilla deopt or uncommon trap we MUST NOT stop at a safepoint once
   175   // the vframeArray is created.
   176   //
   178   // Allocate our special deoptimization ResourceMark
   179   DeoptResourceMark* dmark = new DeoptResourceMark(thread);
   180   assert(thread->deopt_mark() == NULL, "Pending deopt!");
   181   thread->set_deopt_mark(dmark);
   183   frame stub_frame = thread->last_frame(); // Makes stack walkable as side effect
   184   RegisterMap map(thread, true);
   185   RegisterMap dummy_map(thread, false);
   186   // Now get the deoptee with a valid map
   187   frame deoptee = stub_frame.sender(&map);
   188   // Set the deoptee nmethod
   189   assert(thread->deopt_nmethod() == NULL, "Pending deopt!");
   190   thread->set_deopt_nmethod(deoptee.cb()->as_nmethod_or_null());
   192   // Create a growable array of VFrames where each VFrame represents an inlined
   193   // Java frame.  This storage is allocated with the usual system arena.
   194   assert(deoptee.is_compiled_frame(), "Wrong frame type");
   195   GrowableArray<compiledVFrame*>* chunk = new GrowableArray<compiledVFrame*>(10);
   196   vframe* vf = vframe::new_vframe(&deoptee, &map, thread);
   197   while (!vf->is_top()) {
   198     assert(vf->is_compiled_frame(), "Wrong frame type");
   199     chunk->push(compiledVFrame::cast(vf));
   200     vf = vf->sender();
   201   }
   202   assert(vf->is_compiled_frame(), "Wrong frame type");
   203   chunk->push(compiledVFrame::cast(vf));
   205 #ifdef COMPILER2
   206   // Reallocate the non-escaping objects and restore their fields. Then
   207   // relock objects if synchronization on them was eliminated.
   208   if (DoEscapeAnalysis) {
   209     if (EliminateAllocations) {
   210       assert (chunk->at(0)->scope() != NULL,"expect only compiled java frames");
   211       GrowableArray<ScopeValue*>* objects = chunk->at(0)->scope()->objects();
   213       // The flag return_oop() indicates call sites which return oop
   214       // in compiled code. Such sites include java method calls,
   215       // runtime calls (for example, used to allocate new objects/arrays
   216       // on slow code path) and any other calls generated in compiled code.
   217       // It is not guaranteed that we can get such information here only
   218       // by analyzing bytecode in deoptimized frames. This is why this flag
   219       // is set during method compilation (see Compile::Process_OopMap_Node()).
   220       bool save_oop_result = chunk->at(0)->scope()->return_oop();
   221       Handle return_value;
   222       if (save_oop_result) {
   223         // Reallocation may trigger GC. If deoptimization happened on return from
   224         // call which returns oop we need to save it since it is not in oopmap.
   225         oop result = deoptee.saved_oop_result(&map);
   226         assert(result == NULL || result->is_oop(), "must be oop");
   227         return_value = Handle(thread, result);
   228         assert(Universe::heap()->is_in_or_null(result), "must be heap pointer");
   229         if (TraceDeoptimization) {
   230           tty->print_cr("SAVED OOP RESULT " INTPTR_FORMAT " in thread " INTPTR_FORMAT, result, thread);
   231         }
   232       }
   233       bool reallocated = false;
   234       if (objects != NULL) {
   235         JRT_BLOCK
   236           reallocated = realloc_objects(thread, &deoptee, objects, THREAD);
   237         JRT_END
   238       }
   239       if (reallocated) {
   240         reassign_fields(&deoptee, &map, objects);
   241 #ifndef PRODUCT
   242         if (TraceDeoptimization) {
   243           ttyLocker ttyl;
   244           tty->print_cr("REALLOC OBJECTS in thread " INTPTR_FORMAT, thread);
   245           print_objects(objects);
   246         }
   247 #endif
   248       }
   249       if (save_oop_result) {
   250         // Restore result.
   251         deoptee.set_saved_oop_result(&map, return_value());
   252       }
   253     }
   254     if (EliminateLocks) {
   255 #ifndef PRODUCT
   256       bool first = true;
   257 #endif
   258       for (int i = 0; i < chunk->length(); i++) {
   259         compiledVFrame* cvf = chunk->at(i);
   260         assert (cvf->scope() != NULL,"expect only compiled java frames");
   261         GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
   262         if (monitors->is_nonempty()) {
   263           relock_objects(monitors, thread);
   264 #ifndef PRODUCT
   265           if (TraceDeoptimization) {
   266             ttyLocker ttyl;
   267             for (int j = 0; j < monitors->length(); j++) {
   268               MonitorInfo* mi = monitors->at(j);
   269               if (mi->eliminated()) {
   270                 if (first) {
   271                   first = false;
   272                   tty->print_cr("RELOCK OBJECTS in thread " INTPTR_FORMAT, thread);
   273                 }
   274                 tty->print_cr("     object <" INTPTR_FORMAT "> locked", mi->owner());
   275               }
   276             }
   277           }
   278 #endif
   279         }
   280       }
   281     }
   282   }
   283 #endif // COMPILER2
   284   // Ensure that no safepoint is taken after pointers have been stored
   285   // in fields of rematerialized objects.  If a safepoint occurs from here on
   286   // out the java state residing in the vframeArray will be missed.
   287   No_Safepoint_Verifier no_safepoint;
   289   vframeArray* array = create_vframeArray(thread, deoptee, &map, chunk);
   291   assert(thread->vframe_array_head() == NULL, "Pending deopt!");;
   292   thread->set_vframe_array_head(array);
   294   // Now that the vframeArray has been created if we have any deferred local writes
   295   // added by jvmti then we can free up that structure as the data is now in the
   296   // vframeArray
   298   if (thread->deferred_locals() != NULL) {
   299     GrowableArray<jvmtiDeferredLocalVariableSet*>* list = thread->deferred_locals();
   300     int i = 0;
   301     do {
   302       // Because of inlining we could have multiple vframes for a single frame
   303       // and several of the vframes could have deferred writes. Find them all.
   304       if (list->at(i)->id() == array->original().id()) {
   305         jvmtiDeferredLocalVariableSet* dlv = list->at(i);
   306         list->remove_at(i);
   307         // individual jvmtiDeferredLocalVariableSet are CHeapObj's
   308         delete dlv;
   309       } else {
   310         i++;
   311       }
   312     } while ( i < list->length() );
   313     if (list->length() == 0) {
   314       thread->set_deferred_locals(NULL);
   315       // free the list and elements back to C heap.
   316       delete list;
   317     }
   319   }
   321 #ifndef SHARK
   322   // Compute the caller frame based on the sender sp of stub_frame and stored frame sizes info.
   323   CodeBlob* cb = stub_frame.cb();
   324   // Verify we have the right vframeArray
   325   assert(cb->frame_size() >= 0, "Unexpected frame size");
   326   intptr_t* unpack_sp = stub_frame.sp() + cb->frame_size();
   328   // If the deopt call site is a MethodHandle invoke call site we have
   329   // to adjust the unpack_sp.
   330   nmethod* deoptee_nm = deoptee.cb()->as_nmethod_or_null();
   331   if (deoptee_nm != NULL && deoptee_nm->is_method_handle_return(deoptee.pc()))
   332     unpack_sp = deoptee.unextended_sp();
   334 #ifdef ASSERT
   335   assert(cb->is_deoptimization_stub() || cb->is_uncommon_trap_stub(), "just checking");
   336   Events::log("fetch unroll sp " INTPTR_FORMAT, unpack_sp);
   337 #endif
   338 #else
   339   intptr_t* unpack_sp = stub_frame.sender(&dummy_map).unextended_sp();
   340 #endif // !SHARK
   342   // This is a guarantee instead of an assert because if vframe doesn't match
   343   // we will unpack the wrong deoptimized frame and wind up in strange places
   344   // where it will be very difficult to figure out what went wrong. Better
   345   // to die an early death here than some very obscure death later when the
   346   // trail is cold.
   347   // Note: on ia64 this guarantee can be fooled by frames with no memory stack
   348   // in that it will fail to detect a problem when there is one. This needs
   349   // more work in tiger timeframe.
   350   guarantee(array->unextended_sp() == unpack_sp, "vframe_array_head must contain the vframeArray to unpack");
   352   int number_of_frames = array->frames();
   354   // Compute the vframes' sizes.  Note that frame_sizes[] entries are ordered from outermost to innermost
   355   // virtual activation, which is the reverse of the elements in the vframes array.
   356   intptr_t* frame_sizes = NEW_C_HEAP_ARRAY(intptr_t, number_of_frames);
   357   // +1 because we always have an interpreter return address for the final slot.
   358   address* frame_pcs = NEW_C_HEAP_ARRAY(address, number_of_frames + 1);
   359   int callee_parameters = 0;
   360   int callee_locals = 0;
   361   int popframe_extra_args = 0;
   362   // Create an interpreter return address for the stub to use as its return
   363   // address so the skeletal frames are perfectly walkable
   364   frame_pcs[number_of_frames] = Interpreter::deopt_entry(vtos, 0);
   366   // PopFrame requires that the preserved incoming arguments from the recently-popped topmost
   367   // activation be put back on the expression stack of the caller for reexecution
   368   if (JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
   369     popframe_extra_args = in_words(thread->popframe_preserved_args_size_in_words());
   370   }
   372   //
   373   // frame_sizes/frame_pcs[0] oldest frame (int or c2i)
   374   // frame_sizes/frame_pcs[1] next oldest frame (int)
   375   // frame_sizes/frame_pcs[n] youngest frame (int)
   376   //
   377   // Now a pc in frame_pcs is actually the return address to the frame's caller (a frame
   378   // owns the space for the return address to it's caller).  Confusing ain't it.
   379   //
   380   // The vframe array can address vframes with indices running from
   381   // 0.._frames-1. Index  0 is the youngest frame and _frame - 1 is the oldest (root) frame.
   382   // When we create the skeletal frames we need the oldest frame to be in the zero slot
   383   // in the frame_sizes/frame_pcs so the assembly code can do a trivial walk.
   384   // so things look a little strange in this loop.
   385   //
   386   for (int index = 0; index < array->frames(); index++ ) {
   387     // frame[number_of_frames - 1 ] = on_stack_size(youngest)
   388     // frame[number_of_frames - 2 ] = on_stack_size(sender(youngest))
   389     // frame[number_of_frames - 3 ] = on_stack_size(sender(sender(youngest)))
   390     frame_sizes[number_of_frames - 1 - index] = BytesPerWord * array->element(index)->on_stack_size(callee_parameters,
   391                                                                                                     callee_locals,
   392                                                                                                     index == 0,
   393                                                                                                     popframe_extra_args);
   394     // This pc doesn't have to be perfect just good enough to identify the frame
   395     // as interpreted so the skeleton frame will be walkable
   396     // The correct pc will be set when the skeleton frame is completely filled out
   397     // The final pc we store in the loop is wrong and will be overwritten below
   398     frame_pcs[number_of_frames - 1 - index ] = Interpreter::deopt_entry(vtos, 0) - frame::pc_return_offset;
   400     callee_parameters = array->element(index)->method()->size_of_parameters();
   401     callee_locals = array->element(index)->method()->max_locals();
   402     popframe_extra_args = 0;
   403   }
   405   // Compute whether the root vframe returns a float or double value.
   406   BasicType return_type;
   407   {
   408     HandleMark hm;
   409     methodHandle method(thread, array->element(0)->method());
   410     Bytecode_invoke invoke = Bytecode_invoke_check(method, array->element(0)->bci());
   411     return_type = invoke.is_valid() ? invoke.result_type() : T_ILLEGAL;
   412   }
   414   // Compute information for handling adapters and adjusting the frame size of the caller.
   415   int caller_adjustment = 0;
   417   // Find the current pc for sender of the deoptee. Since the sender may have been deoptimized
   418   // itself since the deoptee vframeArray was created we must get a fresh value of the pc rather
   419   // than simply use array->sender.pc(). This requires us to walk the current set of frames
   420   //
   421   frame deopt_sender = stub_frame.sender(&dummy_map); // First is the deoptee frame
   422   deopt_sender = deopt_sender.sender(&dummy_map);     // Now deoptee caller
   424   // Compute the amount the oldest interpreter frame will have to adjust
   425   // its caller's stack by. If the caller is a compiled frame then
   426   // we pretend that the callee has no parameters so that the
   427   // extension counts for the full amount of locals and not just
   428   // locals-parms. This is because without a c2i adapter the parm
   429   // area as created by the compiled frame will not be usable by
   430   // the interpreter. (Depending on the calling convention there
   431   // may not even be enough space).
   433   // QQQ I'd rather see this pushed down into last_frame_adjust
   434   // and have it take the sender (aka caller).
   436   if (deopt_sender.is_compiled_frame()) {
   437     caller_adjustment = last_frame_adjust(0, callee_locals);
   438   } else if (callee_locals > callee_parameters) {
   439     // The caller frame may need extending to accommodate
   440     // non-parameter locals of the first unpacked interpreted frame.
   441     // Compute that adjustment.
   442     caller_adjustment = last_frame_adjust(callee_parameters, callee_locals);
   443   }
   446   // If the sender is deoptimized the we must retrieve the address of the handler
   447   // since the frame will "magically" show the original pc before the deopt
   448   // and we'd undo the deopt.
   450   frame_pcs[0] = deopt_sender.raw_pc();
   452 #ifndef SHARK
   453   assert(CodeCache::find_blob_unsafe(frame_pcs[0]) != NULL, "bad pc");
   454 #endif // SHARK
   456   UnrollBlock* info = new UnrollBlock(array->frame_size() * BytesPerWord,
   457                                       caller_adjustment * BytesPerWord,
   458                                       number_of_frames,
   459                                       frame_sizes,
   460                                       frame_pcs,
   461                                       return_type);
   462 #if defined(IA32) || defined(AMD64)
   463   // We need a way to pass fp to the unpacking code so the skeletal frames
   464   // come out correct. This is only needed for x86 because of c2 using ebp
   465   // as an allocatable register. So this update is useless (and harmless)
   466   // on the other platforms. It would be nice to do this in a different
   467   // way but even the old style deoptimization had a problem with deriving
   468   // this value. NEEDS_CLEANUP
   469   // Note: now that c1 is using c2's deopt blob we must do this on all
   470   // x86 based platforms
   471   intptr_t** fp_addr = (intptr_t**) (((address)info) + info->initial_fp_offset_in_bytes());
   472   *fp_addr = array->sender().fp(); // was adapter_caller
   473 #endif /* IA32 || AMD64 */
   475   if (array->frames() > 1) {
   476     if (VerifyStack && TraceDeoptimization) {
   477       tty->print_cr("Deoptimizing method containing inlining");
   478     }
   479   }
   481   array->set_unroll_block(info);
   482   return info;
   483 }
   485 // Called to cleanup deoptimization data structures in normal case
   486 // after unpacking to stack and when stack overflow error occurs
   487 void Deoptimization::cleanup_deopt_info(JavaThread *thread,
   488                                         vframeArray *array) {
   490   // Get array if coming from exception
   491   if (array == NULL) {
   492     array = thread->vframe_array_head();
   493   }
   494   thread->set_vframe_array_head(NULL);
   496   // Free the previous UnrollBlock
   497   vframeArray* old_array = thread->vframe_array_last();
   498   thread->set_vframe_array_last(array);
   500   if (old_array != NULL) {
   501     UnrollBlock* old_info = old_array->unroll_block();
   502     old_array->set_unroll_block(NULL);
   503     delete old_info;
   504     delete old_array;
   505   }
   507   // Deallocate any resource creating in this routine and any ResourceObjs allocated
   508   // inside the vframeArray (StackValueCollections)
   510   delete thread->deopt_mark();
   511   thread->set_deopt_mark(NULL);
   512   thread->set_deopt_nmethod(NULL);
   515   if (JvmtiExport::can_pop_frame()) {
   516 #ifndef CC_INTERP
   517     // Regardless of whether we entered this routine with the pending
   518     // popframe condition bit set, we should always clear it now
   519     thread->clear_popframe_condition();
   520 #else
   521     // C++ interpeter will clear has_pending_popframe when it enters
   522     // with method_resume. For deopt_resume2 we clear it now.
   523     if (thread->popframe_forcing_deopt_reexecution())
   524         thread->clear_popframe_condition();
   525 #endif /* CC_INTERP */
   526   }
   528   // unpack_frames() is called at the end of the deoptimization handler
   529   // and (in C2) at the end of the uncommon trap handler. Note this fact
   530   // so that an asynchronous stack walker can work again. This counter is
   531   // incremented at the beginning of fetch_unroll_info() and (in C2) at
   532   // the beginning of uncommon_trap().
   533   thread->dec_in_deopt_handler();
   534 }
   537 // Return BasicType of value being returned
   538 JRT_LEAF(BasicType, Deoptimization::unpack_frames(JavaThread* thread, int exec_mode))
   540   // We are already active int he special DeoptResourceMark any ResourceObj's we
   541   // allocate will be freed at the end of the routine.
   543   // It is actually ok to allocate handles in a leaf method. It causes no safepoints,
   544   // but makes the entry a little slower. There is however a little dance we have to
   545   // do in debug mode to get around the NoHandleMark code in the JRT_LEAF macro
   546   ResetNoHandleMark rnhm; // No-op in release/product versions
   547   HandleMark hm;
   549   frame stub_frame = thread->last_frame();
   551   // Since the frame to unpack is the top frame of this thread, the vframe_array_head
   552   // must point to the vframeArray for the unpack frame.
   553   vframeArray* array = thread->vframe_array_head();
   555 #ifndef PRODUCT
   556   if (TraceDeoptimization) {
   557     tty->print_cr("DEOPT UNPACKING thread " INTPTR_FORMAT " vframeArray " INTPTR_FORMAT " mode %d", thread, array, exec_mode);
   558   }
   559 #endif
   561   UnrollBlock* info = array->unroll_block();
   563   // Unpack the interpreter frames and any adapter frame (c2 only) we might create.
   564   array->unpack_to_stack(stub_frame, exec_mode);
   566   BasicType bt = info->return_type();
   568   // If we have an exception pending, claim that the return type is an oop
   569   // so the deopt_blob does not overwrite the exception_oop.
   571   if (exec_mode == Unpack_exception)
   572     bt = T_OBJECT;
   574   // Cleanup thread deopt data
   575   cleanup_deopt_info(thread, array);
   577 #ifndef PRODUCT
   578   if (VerifyStack) {
   579     ResourceMark res_mark;
   581     // Verify that the just-unpacked frames match the interpreter's
   582     // notions of expression stack and locals
   583     vframeArray* cur_array = thread->vframe_array_last();
   584     RegisterMap rm(thread, false);
   585     rm.set_include_argument_oops(false);
   586     bool is_top_frame = true;
   587     int callee_size_of_parameters = 0;
   588     int callee_max_locals = 0;
   589     for (int i = 0; i < cur_array->frames(); i++) {
   590       vframeArrayElement* el = cur_array->element(i);
   591       frame* iframe = el->iframe();
   592       guarantee(iframe->is_interpreted_frame(), "Wrong frame type");
   594       // Get the oop map for this bci
   595       InterpreterOopMap mask;
   596       int cur_invoke_parameter_size = 0;
   597       bool try_next_mask = false;
   598       int next_mask_expression_stack_size = -1;
   599       int top_frame_expression_stack_adjustment = 0;
   600       methodHandle mh(thread, iframe->interpreter_frame_method());
   601       OopMapCache::compute_one_oop_map(mh, iframe->interpreter_frame_bci(), &mask);
   602       BytecodeStream str(mh);
   603       str.set_start(iframe->interpreter_frame_bci());
   604       int max_bci = mh->code_size();
   605       // Get to the next bytecode if possible
   606       assert(str.bci() < max_bci, "bci in interpreter frame out of bounds");
   607       // Check to see if we can grab the number of outgoing arguments
   608       // at an uncommon trap for an invoke (where the compiler
   609       // generates debug info before the invoke has executed)
   610       Bytecodes::Code cur_code = str.next();
   611       if (cur_code == Bytecodes::_invokevirtual ||
   612           cur_code == Bytecodes::_invokespecial ||
   613           cur_code == Bytecodes::_invokestatic  ||
   614           cur_code == Bytecodes::_invokeinterface) {
   615         Bytecode_invoke invoke(mh, iframe->interpreter_frame_bci());
   616         Symbol* signature = invoke.signature();
   617         ArgumentSizeComputer asc(signature);
   618         cur_invoke_parameter_size = asc.size();
   619         if (cur_code != Bytecodes::_invokestatic) {
   620           // Add in receiver
   621           ++cur_invoke_parameter_size;
   622         }
   623       }
   624       if (str.bci() < max_bci) {
   625         Bytecodes::Code bc = str.next();
   626         if (bc >= 0) {
   627           // The interpreter oop map generator reports results before
   628           // the current bytecode has executed except in the case of
   629           // calls. It seems to be hard to tell whether the compiler
   630           // has emitted debug information matching the "state before"
   631           // a given bytecode or the state after, so we try both
   632           switch (cur_code) {
   633             case Bytecodes::_invokevirtual:
   634             case Bytecodes::_invokespecial:
   635             case Bytecodes::_invokestatic:
   636             case Bytecodes::_invokeinterface:
   637             case Bytecodes::_athrow:
   638               break;
   639             default: {
   640               InterpreterOopMap next_mask;
   641               OopMapCache::compute_one_oop_map(mh, str.bci(), &next_mask);
   642               next_mask_expression_stack_size = next_mask.expression_stack_size();
   643               // Need to subtract off the size of the result type of
   644               // the bytecode because this is not described in the
   645               // debug info but returned to the interpreter in the TOS
   646               // caching register
   647               BasicType bytecode_result_type = Bytecodes::result_type(cur_code);
   648               if (bytecode_result_type != T_ILLEGAL) {
   649                 top_frame_expression_stack_adjustment = type2size[bytecode_result_type];
   650               }
   651               assert(top_frame_expression_stack_adjustment >= 0, "");
   652               try_next_mask = true;
   653               break;
   654             }
   655           }
   656         }
   657       }
   659       // Verify stack depth and oops in frame
   660       // This assertion may be dependent on the platform we're running on and may need modification (tested on x86 and sparc)
   661       if (!(
   662             /* SPARC */
   663             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_size_of_parameters) ||
   664             /* x86 */
   665             (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + callee_max_locals) ||
   666             (try_next_mask &&
   667              (iframe->interpreter_frame_expression_stack_size() == (next_mask_expression_stack_size -
   668                                                                     top_frame_expression_stack_adjustment))) ||
   669             (is_top_frame && (exec_mode == Unpack_exception) && iframe->interpreter_frame_expression_stack_size() == 0) ||
   670             (is_top_frame && (exec_mode == Unpack_uncommon_trap || exec_mode == Unpack_reexecute) &&
   671              (iframe->interpreter_frame_expression_stack_size() == mask.expression_stack_size() + cur_invoke_parameter_size))
   672             )) {
   673         ttyLocker ttyl;
   675         // Print out some information that will help us debug the problem
   676         tty->print_cr("Wrong number of expression stack elements during deoptimization");
   677         tty->print_cr("  Error occurred while verifying frame %d (0..%d, 0 is topmost)", i, cur_array->frames() - 1);
   678         tty->print_cr("  Fabricated interpreter frame had %d expression stack elements",
   679                       iframe->interpreter_frame_expression_stack_size());
   680         tty->print_cr("  Interpreter oop map had %d expression stack elements", mask.expression_stack_size());
   681         tty->print_cr("  try_next_mask = %d", try_next_mask);
   682         tty->print_cr("  next_mask_expression_stack_size = %d", next_mask_expression_stack_size);
   683         tty->print_cr("  callee_size_of_parameters = %d", callee_size_of_parameters);
   684         tty->print_cr("  callee_max_locals = %d", callee_max_locals);
   685         tty->print_cr("  top_frame_expression_stack_adjustment = %d", top_frame_expression_stack_adjustment);
   686         tty->print_cr("  exec_mode = %d", exec_mode);
   687         tty->print_cr("  cur_invoke_parameter_size = %d", cur_invoke_parameter_size);
   688         tty->print_cr("  Thread = " INTPTR_FORMAT ", thread ID = " UINTX_FORMAT, thread, thread->osthread()->thread_id());
   689         tty->print_cr("  Interpreted frames:");
   690         for (int k = 0; k < cur_array->frames(); k++) {
   691           vframeArrayElement* el = cur_array->element(k);
   692           tty->print_cr("    %s (bci %d)", el->method()->name_and_sig_as_C_string(), el->bci());
   693         }
   694         cur_array->print_on_2(tty);
   695         guarantee(false, "wrong number of expression stack elements during deopt");
   696       }
   697       VerifyOopClosure verify;
   698       iframe->oops_interpreted_do(&verify, &rm, false);
   699       callee_size_of_parameters = mh->size_of_parameters();
   700       callee_max_locals = mh->max_locals();
   701       is_top_frame = false;
   702     }
   703   }
   704 #endif /* !PRODUCT */
   707   return bt;
   708 JRT_END
   711 int Deoptimization::deoptimize_dependents() {
   712   Threads::deoptimized_wrt_marked_nmethods();
   713   return 0;
   714 }
   717 #ifdef COMPILER2
   718 bool Deoptimization::realloc_objects(JavaThread* thread, frame* fr, GrowableArray<ScopeValue*>* objects, TRAPS) {
   719   Handle pending_exception(thread->pending_exception());
   720   const char* exception_file = thread->exception_file();
   721   int exception_line = thread->exception_line();
   722   thread->clear_pending_exception();
   724   for (int i = 0; i < objects->length(); i++) {
   725     assert(objects->at(i)->is_object(), "invalid debug information");
   726     ObjectValue* sv = (ObjectValue*) objects->at(i);
   728     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   729     oop obj = NULL;
   731     if (k->oop_is_instance()) {
   732       instanceKlass* ik = instanceKlass::cast(k());
   733       obj = ik->allocate_instance(CHECK_(false));
   734     } else if (k->oop_is_typeArray()) {
   735       typeArrayKlass* ak = typeArrayKlass::cast(k());
   736       assert(sv->field_size() % type2size[ak->element_type()] == 0, "non-integral array length");
   737       int len = sv->field_size() / type2size[ak->element_type()];
   738       obj = ak->allocate(len, CHECK_(false));
   739     } else if (k->oop_is_objArray()) {
   740       objArrayKlass* ak = objArrayKlass::cast(k());
   741       obj = ak->allocate(sv->field_size(), CHECK_(false));
   742     }
   744     assert(obj != NULL, "allocation failed");
   745     assert(sv->value().is_null(), "redundant reallocation");
   746     sv->set_value(obj);
   747   }
   749   if (pending_exception.not_null()) {
   750     thread->set_pending_exception(pending_exception(), exception_file, exception_line);
   751   }
   753   return true;
   754 }
   756 // This assumes that the fields are stored in ObjectValue in the same order
   757 // they are yielded by do_nonstatic_fields.
   758 class FieldReassigner: public FieldClosure {
   759   frame* _fr;
   760   RegisterMap* _reg_map;
   761   ObjectValue* _sv;
   762   instanceKlass* _ik;
   763   oop _obj;
   765   int _i;
   766 public:
   767   FieldReassigner(frame* fr, RegisterMap* reg_map, ObjectValue* sv, oop obj) :
   768     _fr(fr), _reg_map(reg_map), _sv(sv), _obj(obj), _i(0) {}
   770   int i() const { return _i; }
   773   void do_field(fieldDescriptor* fd) {
   774     intptr_t val;
   775     StackValue* value =
   776       StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(i()));
   777     int offset = fd->offset();
   778     switch (fd->field_type()) {
   779     case T_OBJECT: case T_ARRAY:
   780       assert(value->type() == T_OBJECT, "Agreement.");
   781       _obj->obj_field_put(offset, value->get_obj()());
   782       break;
   784     case T_LONG: case T_DOUBLE: {
   785       assert(value->type() == T_INT, "Agreement.");
   786       StackValue* low =
   787         StackValue::create_stack_value(_fr, _reg_map, _sv->field_at(++_i));
   788 #ifdef _LP64
   789       jlong res = (jlong)low->get_int();
   790 #else
   791 #ifdef SPARC
   792       // For SPARC we have to swap high and low words.
   793       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
   794 #else
   795       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
   796 #endif //SPARC
   797 #endif
   798       _obj->long_field_put(offset, res);
   799       break;
   800     }
   801     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
   802     case T_INT: case T_FLOAT: // 4 bytes.
   803       assert(value->type() == T_INT, "Agreement.");
   804       val = value->get_int();
   805       _obj->int_field_put(offset, (jint)*((jint*)&val));
   806       break;
   808     case T_SHORT: case T_CHAR: // 2 bytes
   809       assert(value->type() == T_INT, "Agreement.");
   810       val = value->get_int();
   811       _obj->short_field_put(offset, (jshort)*((jint*)&val));
   812       break;
   814     case T_BOOLEAN: case T_BYTE: // 1 byte
   815       assert(value->type() == T_INT, "Agreement.");
   816       val = value->get_int();
   817       _obj->bool_field_put(offset, (jboolean)*((jint*)&val));
   818       break;
   820     default:
   821       ShouldNotReachHere();
   822     }
   823     _i++;
   824   }
   825 };
   827 // restore elements of an eliminated type array
   828 void Deoptimization::reassign_type_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, typeArrayOop obj, BasicType type) {
   829   int index = 0;
   830   intptr_t val;
   832   for (int i = 0; i < sv->field_size(); i++) {
   833     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
   834     switch(type) {
   835     case T_LONG: case T_DOUBLE: {
   836       assert(value->type() == T_INT, "Agreement.");
   837       StackValue* low =
   838         StackValue::create_stack_value(fr, reg_map, sv->field_at(++i));
   839 #ifdef _LP64
   840       jlong res = (jlong)low->get_int();
   841 #else
   842 #ifdef SPARC
   843       // For SPARC we have to swap high and low words.
   844       jlong res = jlong_from((jint)low->get_int(), (jint)value->get_int());
   845 #else
   846       jlong res = jlong_from((jint)value->get_int(), (jint)low->get_int());
   847 #endif //SPARC
   848 #endif
   849       obj->long_at_put(index, res);
   850       break;
   851     }
   853     // Have to cast to INT (32 bits) pointer to avoid little/big-endian problem.
   854     case T_INT: case T_FLOAT: // 4 bytes.
   855       assert(value->type() == T_INT, "Agreement.");
   856       val = value->get_int();
   857       obj->int_at_put(index, (jint)*((jint*)&val));
   858       break;
   860     case T_SHORT: case T_CHAR: // 2 bytes
   861       assert(value->type() == T_INT, "Agreement.");
   862       val = value->get_int();
   863       obj->short_at_put(index, (jshort)*((jint*)&val));
   864       break;
   866     case T_BOOLEAN: case T_BYTE: // 1 byte
   867       assert(value->type() == T_INT, "Agreement.");
   868       val = value->get_int();
   869       obj->bool_at_put(index, (jboolean)*((jint*)&val));
   870       break;
   872       default:
   873         ShouldNotReachHere();
   874     }
   875     index++;
   876   }
   877 }
   880 // restore fields of an eliminated object array
   881 void Deoptimization::reassign_object_array_elements(frame* fr, RegisterMap* reg_map, ObjectValue* sv, objArrayOop obj) {
   882   for (int i = 0; i < sv->field_size(); i++) {
   883     StackValue* value = StackValue::create_stack_value(fr, reg_map, sv->field_at(i));
   884     assert(value->type() == T_OBJECT, "object element expected");
   885     obj->obj_at_put(i, value->get_obj()());
   886   }
   887 }
   890 // restore fields of all eliminated objects and arrays
   891 void Deoptimization::reassign_fields(frame* fr, RegisterMap* reg_map, GrowableArray<ScopeValue*>* objects) {
   892   for (int i = 0; i < objects->length(); i++) {
   893     ObjectValue* sv = (ObjectValue*) objects->at(i);
   894     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   895     Handle obj = sv->value();
   896     assert(obj.not_null(), "reallocation was missed");
   898     if (k->oop_is_instance()) {
   899       instanceKlass* ik = instanceKlass::cast(k());
   900       FieldReassigner reassign(fr, reg_map, sv, obj());
   901       ik->do_nonstatic_fields(&reassign);
   902     } else if (k->oop_is_typeArray()) {
   903       typeArrayKlass* ak = typeArrayKlass::cast(k());
   904       reassign_type_array_elements(fr, reg_map, sv, (typeArrayOop) obj(), ak->element_type());
   905     } else if (k->oop_is_objArray()) {
   906       reassign_object_array_elements(fr, reg_map, sv, (objArrayOop) obj());
   907     }
   908   }
   909 }
   912 // relock objects for which synchronization was eliminated
   913 void Deoptimization::relock_objects(GrowableArray<MonitorInfo*>* monitors, JavaThread* thread) {
   914   for (int i = 0; i < monitors->length(); i++) {
   915     MonitorInfo* mon_info = monitors->at(i);
   916     if (mon_info->eliminated()) {
   917       assert(mon_info->owner() != NULL, "reallocation was missed");
   918       Handle obj = Handle(mon_info->owner());
   919       markOop mark = obj->mark();
   920       if (UseBiasedLocking && mark->has_bias_pattern()) {
   921         // New allocated objects may have the mark set to anonymously biased.
   922         // Also the deoptimized method may called methods with synchronization
   923         // where the thread-local object is bias locked to the current thread.
   924         assert(mark->is_biased_anonymously() ||
   925                mark->biased_locker() == thread, "should be locked to current thread");
   926         // Reset mark word to unbiased prototype.
   927         markOop unbiased_prototype = markOopDesc::prototype()->set_age(mark->age());
   928         obj->set_mark(unbiased_prototype);
   929       }
   930       BasicLock* lock = mon_info->lock();
   931       ObjectSynchronizer::slow_enter(obj, lock, thread);
   932     }
   933     assert(mon_info->owner()->is_locked(), "object must be locked now");
   934   }
   935 }
   938 #ifndef PRODUCT
   939 // print information about reallocated objects
   940 void Deoptimization::print_objects(GrowableArray<ScopeValue*>* objects) {
   941   fieldDescriptor fd;
   943   for (int i = 0; i < objects->length(); i++) {
   944     ObjectValue* sv = (ObjectValue*) objects->at(i);
   945     KlassHandle k(((ConstantOopReadValue*) sv->klass())->value()());
   946     Handle obj = sv->value();
   948     tty->print("     object <" INTPTR_FORMAT "> of type ", sv->value()());
   949     k->as_klassOop()->print_value();
   950     tty->print(" allocated (%d bytes)", obj->size() * HeapWordSize);
   951     tty->cr();
   953     if (Verbose) {
   954       k->oop_print_on(obj(), tty);
   955     }
   956   }
   957 }
   958 #endif
   959 #endif // COMPILER2
   961 vframeArray* Deoptimization::create_vframeArray(JavaThread* thread, frame fr, RegisterMap *reg_map, GrowableArray<compiledVFrame*>* chunk) {
   963 #ifndef PRODUCT
   964   if (TraceDeoptimization) {
   965     ttyLocker ttyl;
   966     tty->print("DEOPT PACKING thread " INTPTR_FORMAT " ", thread);
   967     fr.print_on(tty);
   968     tty->print_cr("     Virtual frames (innermost first):");
   969     for (int index = 0; index < chunk->length(); index++) {
   970       compiledVFrame* vf = chunk->at(index);
   971       tty->print("       %2d - ", index);
   972       vf->print_value();
   973       int bci = chunk->at(index)->raw_bci();
   974       const char* code_name;
   975       if (bci == SynchronizationEntryBCI) {
   976         code_name = "sync entry";
   977       } else {
   978         Bytecodes::Code code = vf->method()->code_at(bci);
   979         code_name = Bytecodes::name(code);
   980       }
   981       tty->print(" - %s", code_name);
   982       tty->print_cr(" @ bci %d ", bci);
   983       if (Verbose) {
   984         vf->print();
   985         tty->cr();
   986       }
   987     }
   988   }
   989 #endif
   991   // Register map for next frame (used for stack crawl).  We capture
   992   // the state of the deopt'ing frame's caller.  Thus if we need to
   993   // stuff a C2I adapter we can properly fill in the callee-save
   994   // register locations.
   995   frame caller = fr.sender(reg_map);
   996   int frame_size = caller.sp() - fr.sp();
   998   frame sender = caller;
  1000   // Since the Java thread being deoptimized will eventually adjust it's own stack,
  1001   // the vframeArray containing the unpacking information is allocated in the C heap.
  1002   // For Compiler1, the caller of the deoptimized frame is saved for use by unpack_frames().
  1003   vframeArray* array = vframeArray::allocate(thread, frame_size, chunk, reg_map, sender, caller, fr);
  1005   // Compare the vframeArray to the collected vframes
  1006   assert(array->structural_compare(thread, chunk), "just checking");
  1007   Events::log("# vframes = %d", (intptr_t)chunk->length());
  1009 #ifndef PRODUCT
  1010   if (TraceDeoptimization) {
  1011     ttyLocker ttyl;
  1012     tty->print_cr("     Created vframeArray " INTPTR_FORMAT, array);
  1014 #endif // PRODUCT
  1016   return array;
  1020 static void collect_monitors(compiledVFrame* cvf, GrowableArray<Handle>* objects_to_revoke) {
  1021   GrowableArray<MonitorInfo*>* monitors = cvf->monitors();
  1022   for (int i = 0; i < monitors->length(); i++) {
  1023     MonitorInfo* mon_info = monitors->at(i);
  1024     if (!mon_info->eliminated() && mon_info->owner() != NULL) {
  1025       objects_to_revoke->append(Handle(mon_info->owner()));
  1031 void Deoptimization::revoke_biases_of_monitors(JavaThread* thread, frame fr, RegisterMap* map) {
  1032   if (!UseBiasedLocking) {
  1033     return;
  1036   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
  1038   // Unfortunately we don't have a RegisterMap available in most of
  1039   // the places we want to call this routine so we need to walk the
  1040   // stack again to update the register map.
  1041   if (map == NULL || !map->update_map()) {
  1042     StackFrameStream sfs(thread, true);
  1043     bool found = false;
  1044     while (!found && !sfs.is_done()) {
  1045       frame* cur = sfs.current();
  1046       sfs.next();
  1047       found = cur->id() == fr.id();
  1049     assert(found, "frame to be deoptimized not found on target thread's stack");
  1050     map = sfs.register_map();
  1053   vframe* vf = vframe::new_vframe(&fr, map, thread);
  1054   compiledVFrame* cvf = compiledVFrame::cast(vf);
  1055   // Revoke monitors' biases in all scopes
  1056   while (!cvf->is_top()) {
  1057     collect_monitors(cvf, objects_to_revoke);
  1058     cvf = compiledVFrame::cast(cvf->sender());
  1060   collect_monitors(cvf, objects_to_revoke);
  1062   if (SafepointSynchronize::is_at_safepoint()) {
  1063     BiasedLocking::revoke_at_safepoint(objects_to_revoke);
  1064   } else {
  1065     BiasedLocking::revoke(objects_to_revoke);
  1070 void Deoptimization::revoke_biases_of_monitors(CodeBlob* cb) {
  1071   if (!UseBiasedLocking) {
  1072     return;
  1075   assert(SafepointSynchronize::is_at_safepoint(), "must only be called from safepoint");
  1076   GrowableArray<Handle>* objects_to_revoke = new GrowableArray<Handle>();
  1077   for (JavaThread* jt = Threads::first(); jt != NULL ; jt = jt->next()) {
  1078     if (jt->has_last_Java_frame()) {
  1079       StackFrameStream sfs(jt, true);
  1080       while (!sfs.is_done()) {
  1081         frame* cur = sfs.current();
  1082         if (cb->contains(cur->pc())) {
  1083           vframe* vf = vframe::new_vframe(cur, sfs.register_map(), jt);
  1084           compiledVFrame* cvf = compiledVFrame::cast(vf);
  1085           // Revoke monitors' biases in all scopes
  1086           while (!cvf->is_top()) {
  1087             collect_monitors(cvf, objects_to_revoke);
  1088             cvf = compiledVFrame::cast(cvf->sender());
  1090           collect_monitors(cvf, objects_to_revoke);
  1092         sfs.next();
  1096   BiasedLocking::revoke_at_safepoint(objects_to_revoke);
  1100 void Deoptimization::deoptimize_single_frame(JavaThread* thread, frame fr) {
  1101   assert(fr.can_be_deoptimized(), "checking frame type");
  1103   gather_statistics(Reason_constraint, Action_none, Bytecodes::_illegal);
  1105   EventMark m("Deoptimization (pc=" INTPTR_FORMAT ", sp=" INTPTR_FORMAT ")", fr.pc(), fr.id());
  1107   // Patch the nmethod so that when execution returns to it we will
  1108   // deopt the execution state and return to the interpreter.
  1109   fr.deoptimize(thread);
  1112 void Deoptimization::deoptimize(JavaThread* thread, frame fr, RegisterMap *map) {
  1113   // Deoptimize only if the frame comes from compile code.
  1114   // Do not deoptimize the frame which is already patched
  1115   // during the execution of the loops below.
  1116   if (!fr.is_compiled_frame() || fr.is_deoptimized_frame()) {
  1117     return;
  1119   ResourceMark rm;
  1120   DeoptimizationMarker dm;
  1121   if (UseBiasedLocking) {
  1122     revoke_biases_of_monitors(thread, fr, map);
  1124   deoptimize_single_frame(thread, fr);
  1129 void Deoptimization::deoptimize_frame_internal(JavaThread* thread, intptr_t* id) {
  1130   assert(thread == Thread::current() || SafepointSynchronize::is_at_safepoint(),
  1131          "can only deoptimize other thread at a safepoint");
  1132   // Compute frame and register map based on thread and sp.
  1133   RegisterMap reg_map(thread, UseBiasedLocking);
  1134   frame fr = thread->last_frame();
  1135   while (fr.id() != id) {
  1136     fr = fr.sender(&reg_map);
  1138   deoptimize(thread, fr, &reg_map);
  1142 void Deoptimization::deoptimize_frame(JavaThread* thread, intptr_t* id) {
  1143   if (thread == Thread::current()) {
  1144     Deoptimization::deoptimize_frame_internal(thread, id);
  1145   } else {
  1146     VM_DeoptimizeFrame deopt(thread, id);
  1147     VMThread::execute(&deopt);
  1152 // JVMTI PopFrame support
  1153 JRT_LEAF(void, Deoptimization::popframe_preserve_args(JavaThread* thread, int bytes_to_save, void* start_address))
  1155   thread->popframe_preserve_args(in_ByteSize(bytes_to_save), start_address);
  1157 JRT_END
  1160 #if defined(COMPILER2) || defined(SHARK)
  1161 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index, TRAPS) {
  1162   // in case of an unresolved klass entry, load the class.
  1163   if (constant_pool->tag_at(index).is_unresolved_klass()) {
  1164     klassOop tk = constant_pool->klass_at(index, CHECK);
  1165     return;
  1168   if (!constant_pool->tag_at(index).is_symbol()) return;
  1170   Handle class_loader (THREAD, instanceKlass::cast(constant_pool->pool_holder())->class_loader());
  1171   Symbol*  symbol  = constant_pool->symbol_at(index);
  1173   // class name?
  1174   if (symbol->byte_at(0) != '(') {
  1175     Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
  1176     SystemDictionary::resolve_or_null(symbol, class_loader, protection_domain, CHECK);
  1177     return;
  1180   // then it must be a signature!
  1181   ResourceMark rm(THREAD);
  1182   for (SignatureStream ss(symbol); !ss.is_done(); ss.next()) {
  1183     if (ss.is_object()) {
  1184       Symbol* class_name = ss.as_symbol(CHECK);
  1185       Handle protection_domain (THREAD, Klass::cast(constant_pool->pool_holder())->protection_domain());
  1186       SystemDictionary::resolve_or_null(class_name, class_loader, protection_domain, CHECK);
  1192 void Deoptimization::load_class_by_index(constantPoolHandle constant_pool, int index) {
  1193   EXCEPTION_MARK;
  1194   load_class_by_index(constant_pool, index, THREAD);
  1195   if (HAS_PENDING_EXCEPTION) {
  1196     // Exception happened during classloading. We ignore the exception here, since it
  1197     // is going to be rethrown since the current activation is going to be deoptimzied and
  1198     // the interpreter will re-execute the bytecode.
  1199     CLEAR_PENDING_EXCEPTION;
  1203 JRT_ENTRY(void, Deoptimization::uncommon_trap_inner(JavaThread* thread, jint trap_request)) {
  1204   HandleMark hm;
  1206   // uncommon_trap() is called at the beginning of the uncommon trap
  1207   // handler. Note this fact before we start generating temporary frames
  1208   // that can confuse an asynchronous stack walker. This counter is
  1209   // decremented at the end of unpack_frames().
  1210   thread->inc_in_deopt_handler();
  1212   // We need to update the map if we have biased locking.
  1213   RegisterMap reg_map(thread, UseBiasedLocking);
  1214   frame stub_frame = thread->last_frame();
  1215   frame fr = stub_frame.sender(&reg_map);
  1216   // Make sure the calling nmethod is not getting deoptimized and removed
  1217   // before we are done with it.
  1218   nmethodLocker nl(fr.pc());
  1221     ResourceMark rm;
  1223     // Revoke biases of any monitors in the frame to ensure we can migrate them
  1224     revoke_biases_of_monitors(thread, fr, &reg_map);
  1226     DeoptReason reason = trap_request_reason(trap_request);
  1227     DeoptAction action = trap_request_action(trap_request);
  1228     jint unloaded_class_index = trap_request_index(trap_request); // CP idx or -1
  1230     Events::log("Uncommon trap occurred @" INTPTR_FORMAT " unloaded_class_index = %d", fr.pc(), (int) trap_request);
  1231     vframe*  vf  = vframe::new_vframe(&fr, &reg_map, thread);
  1232     compiledVFrame* cvf = compiledVFrame::cast(vf);
  1234     nmethod* nm = cvf->code();
  1236     ScopeDesc*      trap_scope  = cvf->scope();
  1237     methodHandle    trap_method = trap_scope->method();
  1238     int             trap_bci    = trap_scope->bci();
  1239     Bytecodes::Code trap_bc     = trap_method->java_code_at(trap_bci);
  1241     // Record this event in the histogram.
  1242     gather_statistics(reason, action, trap_bc);
  1244     // Ensure that we can record deopt. history:
  1245     bool create_if_missing = ProfileTraps;
  1247     methodDataHandle trap_mdo
  1248       (THREAD, get_method_data(thread, trap_method, create_if_missing));
  1250     // Print a bunch of diagnostics, if requested.
  1251     if (TraceDeoptimization || LogCompilation) {
  1252       ResourceMark rm;
  1253       ttyLocker ttyl;
  1254       char buf[100];
  1255       if (xtty != NULL) {
  1256         xtty->begin_head("uncommon_trap thread='" UINTX_FORMAT"' %s",
  1257                          os::current_thread_id(),
  1258                          format_trap_request(buf, sizeof(buf), trap_request));
  1259         nm->log_identity(xtty);
  1261       Symbol* class_name = NULL;
  1262       bool unresolved = false;
  1263       if (unloaded_class_index >= 0) {
  1264         constantPoolHandle constants (THREAD, trap_method->constants());
  1265         if (constants->tag_at(unloaded_class_index).is_unresolved_klass()) {
  1266           class_name = constants->klass_name_at(unloaded_class_index);
  1267           unresolved = true;
  1268           if (xtty != NULL)
  1269             xtty->print(" unresolved='1'");
  1270         } else if (constants->tag_at(unloaded_class_index).is_symbol()) {
  1271           class_name = constants->symbol_at(unloaded_class_index);
  1273         if (xtty != NULL)
  1274           xtty->name(class_name);
  1276       if (xtty != NULL && trap_mdo.not_null()) {
  1277         // Dump the relevant MDO state.
  1278         // This is the deopt count for the current reason, any previous
  1279         // reasons or recompiles seen at this point.
  1280         int dcnt = trap_mdo->trap_count(reason);
  1281         if (dcnt != 0)
  1282           xtty->print(" count='%d'", dcnt);
  1283         ProfileData* pdata = trap_mdo->bci_to_data(trap_bci);
  1284         int dos = (pdata == NULL)? 0: pdata->trap_state();
  1285         if (dos != 0) {
  1286           xtty->print(" state='%s'", format_trap_state(buf, sizeof(buf), dos));
  1287           if (trap_state_is_recompiled(dos)) {
  1288             int recnt2 = trap_mdo->overflow_recompile_count();
  1289             if (recnt2 != 0)
  1290               xtty->print(" recompiles2='%d'", recnt2);
  1294       if (xtty != NULL) {
  1295         xtty->stamp();
  1296         xtty->end_head();
  1298       if (TraceDeoptimization) {  // make noise on the tty
  1299         tty->print("Uncommon trap occurred in");
  1300         nm->method()->print_short_name(tty);
  1301         tty->print(" (@" INTPTR_FORMAT ") thread=%d reason=%s action=%s unloaded_class_index=%d",
  1302                    fr.pc(),
  1303                    (int) os::current_thread_id(),
  1304                    trap_reason_name(reason),
  1305                    trap_action_name(action),
  1306                    unloaded_class_index);
  1307         if (class_name != NULL) {
  1308           tty->print(unresolved ? " unresolved class: " : " symbol: ");
  1309           class_name->print_symbol_on(tty);
  1311         tty->cr();
  1313       if (xtty != NULL) {
  1314         // Log the precise location of the trap.
  1315         for (ScopeDesc* sd = trap_scope; ; sd = sd->sender()) {
  1316           xtty->begin_elem("jvms bci='%d'", sd->bci());
  1317           xtty->method(sd->method());
  1318           xtty->end_elem();
  1319           if (sd->is_top())  break;
  1321         xtty->tail("uncommon_trap");
  1324     // (End diagnostic printout.)
  1326     // Load class if necessary
  1327     if (unloaded_class_index >= 0) {
  1328       constantPoolHandle constants(THREAD, trap_method->constants());
  1329       load_class_by_index(constants, unloaded_class_index);
  1332     // Flush the nmethod if necessary and desirable.
  1333     //
  1334     // We need to avoid situations where we are re-flushing the nmethod
  1335     // because of a hot deoptimization site.  Repeated flushes at the same
  1336     // point need to be detected by the compiler and avoided.  If the compiler
  1337     // cannot avoid them (or has a bug and "refuses" to avoid them), this
  1338     // module must take measures to avoid an infinite cycle of recompilation
  1339     // and deoptimization.  There are several such measures:
  1340     //
  1341     //   1. If a recompilation is ordered a second time at some site X
  1342     //   and for the same reason R, the action is adjusted to 'reinterpret',
  1343     //   to give the interpreter time to exercise the method more thoroughly.
  1344     //   If this happens, the method's overflow_recompile_count is incremented.
  1345     //
  1346     //   2. If the compiler fails to reduce the deoptimization rate, then
  1347     //   the method's overflow_recompile_count will begin to exceed the set
  1348     //   limit PerBytecodeRecompilationCutoff.  If this happens, the action
  1349     //   is adjusted to 'make_not_compilable', and the method is abandoned
  1350     //   to the interpreter.  This is a performance hit for hot methods,
  1351     //   but is better than a disastrous infinite cycle of recompilations.
  1352     //   (Actually, only the method containing the site X is abandoned.)
  1353     //
  1354     //   3. In parallel with the previous measures, if the total number of
  1355     //   recompilations of a method exceeds the much larger set limit
  1356     //   PerMethodRecompilationCutoff, the method is abandoned.
  1357     //   This should only happen if the method is very large and has
  1358     //   many "lukewarm" deoptimizations.  The code which enforces this
  1359     //   limit is elsewhere (class nmethod, class methodOopDesc).
  1360     //
  1361     // Note that the per-BCI 'is_recompiled' bit gives the compiler one chance
  1362     // to recompile at each bytecode independently of the per-BCI cutoff.
  1363     //
  1364     // The decision to update code is up to the compiler, and is encoded
  1365     // in the Action_xxx code.  If the compiler requests Action_none
  1366     // no trap state is changed, no compiled code is changed, and the
  1367     // computation suffers along in the interpreter.
  1368     //
  1369     // The other action codes specify various tactics for decompilation
  1370     // and recompilation.  Action_maybe_recompile is the loosest, and
  1371     // allows the compiled code to stay around until enough traps are seen,
  1372     // and until the compiler gets around to recompiling the trapping method.
  1373     //
  1374     // The other actions cause immediate removal of the present code.
  1376     bool update_trap_state = true;
  1377     bool make_not_entrant = false;
  1378     bool make_not_compilable = false;
  1379     bool reprofile = false;
  1380     switch (action) {
  1381     case Action_none:
  1382       // Keep the old code.
  1383       update_trap_state = false;
  1384       break;
  1385     case Action_maybe_recompile:
  1386       // Do not need to invalidate the present code, but we can
  1387       // initiate another
  1388       // Start compiler without (necessarily) invalidating the nmethod.
  1389       // The system will tolerate the old code, but new code should be
  1390       // generated when possible.
  1391       break;
  1392     case Action_reinterpret:
  1393       // Go back into the interpreter for a while, and then consider
  1394       // recompiling form scratch.
  1395       make_not_entrant = true;
  1396       // Reset invocation counter for outer most method.
  1397       // This will allow the interpreter to exercise the bytecodes
  1398       // for a while before recompiling.
  1399       // By contrast, Action_make_not_entrant is immediate.
  1400       //
  1401       // Note that the compiler will track null_check, null_assert,
  1402       // range_check, and class_check events and log them as if they
  1403       // had been traps taken from compiled code.  This will update
  1404       // the MDO trap history so that the next compilation will
  1405       // properly detect hot trap sites.
  1406       reprofile = true;
  1407       break;
  1408     case Action_make_not_entrant:
  1409       // Request immediate recompilation, and get rid of the old code.
  1410       // Make them not entrant, so next time they are called they get
  1411       // recompiled.  Unloaded classes are loaded now so recompile before next
  1412       // time they are called.  Same for uninitialized.  The interpreter will
  1413       // link the missing class, if any.
  1414       make_not_entrant = true;
  1415       break;
  1416     case Action_make_not_compilable:
  1417       // Give up on compiling this method at all.
  1418       make_not_entrant = true;
  1419       make_not_compilable = true;
  1420       break;
  1421     default:
  1422       ShouldNotReachHere();
  1425     // Setting +ProfileTraps fixes the following, on all platforms:
  1426     // 4852688: ProfileInterpreter is off by default for ia64.  The result is
  1427     // infinite heroic-opt-uncommon-trap/deopt/recompile cycles, since the
  1428     // recompile relies on a methodDataOop to record heroic opt failures.
  1430     // Whether the interpreter is producing MDO data or not, we also need
  1431     // to use the MDO to detect hot deoptimization points and control
  1432     // aggressive optimization.
  1433     bool inc_recompile_count = false;
  1434     ProfileData* pdata = NULL;
  1435     if (ProfileTraps && update_trap_state && trap_mdo.not_null()) {
  1436       assert(trap_mdo() == get_method_data(thread, trap_method, false), "sanity");
  1437       uint this_trap_count = 0;
  1438       bool maybe_prior_trap = false;
  1439       bool maybe_prior_recompile = false;
  1440       pdata = query_update_method_data(trap_mdo, trap_bci, reason,
  1441                                    //outputs:
  1442                                    this_trap_count,
  1443                                    maybe_prior_trap,
  1444                                    maybe_prior_recompile);
  1445       // Because the interpreter also counts null, div0, range, and class
  1446       // checks, these traps from compiled code are double-counted.
  1447       // This is harmless; it just means that the PerXTrapLimit values
  1448       // are in effect a little smaller than they look.
  1450       DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
  1451       if (per_bc_reason != Reason_none) {
  1452         // Now take action based on the partially known per-BCI history.
  1453         if (maybe_prior_trap
  1454             && this_trap_count >= (uint)PerBytecodeTrapLimit) {
  1455           // If there are too many traps at this BCI, force a recompile.
  1456           // This will allow the compiler to see the limit overflow, and
  1457           // take corrective action, if possible.  The compiler generally
  1458           // does not use the exact PerBytecodeTrapLimit value, but instead
  1459           // changes its tactics if it sees any traps at all.  This provides
  1460           // a little hysteresis, delaying a recompile until a trap happens
  1461           // several times.
  1462           //
  1463           // Actually, since there is only one bit of counter per BCI,
  1464           // the possible per-BCI counts are {0,1,(per-method count)}.
  1465           // This produces accurate results if in fact there is only
  1466           // one hot trap site, but begins to get fuzzy if there are
  1467           // many sites.  For example, if there are ten sites each
  1468           // trapping two or more times, they each get the blame for
  1469           // all of their traps.
  1470           make_not_entrant = true;
  1473         // Detect repeated recompilation at the same BCI, and enforce a limit.
  1474         if (make_not_entrant && maybe_prior_recompile) {
  1475           // More than one recompile at this point.
  1476           inc_recompile_count = maybe_prior_trap;
  1478       } else {
  1479         // For reasons which are not recorded per-bytecode, we simply
  1480         // force recompiles unconditionally.
  1481         // (Note that PerMethodRecompilationCutoff is enforced elsewhere.)
  1482         make_not_entrant = true;
  1485       // Go back to the compiler if there are too many traps in this method.
  1486       if (this_trap_count >= (uint)PerMethodTrapLimit) {
  1487         // If there are too many traps in this method, force a recompile.
  1488         // This will allow the compiler to see the limit overflow, and
  1489         // take corrective action, if possible.
  1490         // (This condition is an unlikely backstop only, because the
  1491         // PerBytecodeTrapLimit is more likely to take effect first,
  1492         // if it is applicable.)
  1493         make_not_entrant = true;
  1496       // Here's more hysteresis:  If there has been a recompile at
  1497       // this trap point already, run the method in the interpreter
  1498       // for a while to exercise it more thoroughly.
  1499       if (make_not_entrant && maybe_prior_recompile && maybe_prior_trap) {
  1500         reprofile = true;
  1505     // Take requested actions on the method:
  1507     // Recompile
  1508     if (make_not_entrant) {
  1509       if (!nm->make_not_entrant()) {
  1510         return; // the call did not change nmethod's state
  1513       if (pdata != NULL) {
  1514         // Record the recompilation event, if any.
  1515         int tstate0 = pdata->trap_state();
  1516         int tstate1 = trap_state_set_recompiled(tstate0, true);
  1517         if (tstate1 != tstate0)
  1518           pdata->set_trap_state(tstate1);
  1522     if (inc_recompile_count) {
  1523       trap_mdo->inc_overflow_recompile_count();
  1524       if ((uint)trap_mdo->overflow_recompile_count() >
  1525           (uint)PerBytecodeRecompilationCutoff) {
  1526         // Give up on the method containing the bad BCI.
  1527         if (trap_method() == nm->method()) {
  1528           make_not_compilable = true;
  1529         } else {
  1530           trap_method->set_not_compilable(CompLevel_full_optimization);
  1531           // But give grace to the enclosing nm->method().
  1536     // Reprofile
  1537     if (reprofile) {
  1538       CompilationPolicy::policy()->reprofile(trap_scope, nm->is_osr_method());
  1541     // Give up compiling
  1542     if (make_not_compilable && !nm->method()->is_not_compilable(CompLevel_full_optimization)) {
  1543       assert(make_not_entrant, "consistent");
  1544       nm->method()->set_not_compilable(CompLevel_full_optimization);
  1547   } // Free marked resources
  1550 JRT_END
  1552 methodDataOop
  1553 Deoptimization::get_method_data(JavaThread* thread, methodHandle m,
  1554                                 bool create_if_missing) {
  1555   Thread* THREAD = thread;
  1556   methodDataOop mdo = m()->method_data();
  1557   if (mdo == NULL && create_if_missing && !HAS_PENDING_EXCEPTION) {
  1558     // Build an MDO.  Ignore errors like OutOfMemory;
  1559     // that simply means we won't have an MDO to update.
  1560     methodOopDesc::build_interpreter_method_data(m, THREAD);
  1561     if (HAS_PENDING_EXCEPTION) {
  1562       assert((PENDING_EXCEPTION->is_a(SystemDictionary::OutOfMemoryError_klass())), "we expect only an OOM error here");
  1563       CLEAR_PENDING_EXCEPTION;
  1565     mdo = m()->method_data();
  1567   return mdo;
  1570 ProfileData*
  1571 Deoptimization::query_update_method_data(methodDataHandle trap_mdo,
  1572                                          int trap_bci,
  1573                                          Deoptimization::DeoptReason reason,
  1574                                          //outputs:
  1575                                          uint& ret_this_trap_count,
  1576                                          bool& ret_maybe_prior_trap,
  1577                                          bool& ret_maybe_prior_recompile) {
  1578   uint prior_trap_count = trap_mdo->trap_count(reason);
  1579   uint this_trap_count  = trap_mdo->inc_trap_count(reason);
  1581   // If the runtime cannot find a place to store trap history,
  1582   // it is estimated based on the general condition of the method.
  1583   // If the method has ever been recompiled, or has ever incurred
  1584   // a trap with the present reason , then this BCI is assumed
  1585   // (pessimistically) to be the culprit.
  1586   bool maybe_prior_trap      = (prior_trap_count != 0);
  1587   bool maybe_prior_recompile = (trap_mdo->decompile_count() != 0);
  1588   ProfileData* pdata = NULL;
  1591   // For reasons which are recorded per bytecode, we check per-BCI data.
  1592   DeoptReason per_bc_reason = reason_recorded_per_bytecode_if_any(reason);
  1593   if (per_bc_reason != Reason_none) {
  1594     // Find the profile data for this BCI.  If there isn't one,
  1595     // try to allocate one from the MDO's set of spares.
  1596     // This will let us detect a repeated trap at this point.
  1597     pdata = trap_mdo->allocate_bci_to_data(trap_bci);
  1599     if (pdata != NULL) {
  1600       // Query the trap state of this profile datum.
  1601       int tstate0 = pdata->trap_state();
  1602       if (!trap_state_has_reason(tstate0, per_bc_reason))
  1603         maybe_prior_trap = false;
  1604       if (!trap_state_is_recompiled(tstate0))
  1605         maybe_prior_recompile = false;
  1607       // Update the trap state of this profile datum.
  1608       int tstate1 = tstate0;
  1609       // Record the reason.
  1610       tstate1 = trap_state_add_reason(tstate1, per_bc_reason);
  1611       // Store the updated state on the MDO, for next time.
  1612       if (tstate1 != tstate0)
  1613         pdata->set_trap_state(tstate1);
  1614     } else {
  1615       if (LogCompilation && xtty != NULL) {
  1616         ttyLocker ttyl;
  1617         // Missing MDP?  Leave a small complaint in the log.
  1618         xtty->elem("missing_mdp bci='%d'", trap_bci);
  1623   // Return results:
  1624   ret_this_trap_count = this_trap_count;
  1625   ret_maybe_prior_trap = maybe_prior_trap;
  1626   ret_maybe_prior_recompile = maybe_prior_recompile;
  1627   return pdata;
  1630 void
  1631 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
  1632   ResourceMark rm;
  1633   // Ignored outputs:
  1634   uint ignore_this_trap_count;
  1635   bool ignore_maybe_prior_trap;
  1636   bool ignore_maybe_prior_recompile;
  1637   query_update_method_data(trap_mdo, trap_bci,
  1638                            (DeoptReason)reason,
  1639                            ignore_this_trap_count,
  1640                            ignore_maybe_prior_trap,
  1641                            ignore_maybe_prior_recompile);
  1644 Deoptimization::UnrollBlock* Deoptimization::uncommon_trap(JavaThread* thread, jint trap_request) {
  1646   // Still in Java no safepoints
  1648     // This enters VM and may safepoint
  1649     uncommon_trap_inner(thread, trap_request);
  1651   return fetch_unroll_info_helper(thread);
  1654 // Local derived constants.
  1655 // Further breakdown of DataLayout::trap_state, as promised by DataLayout.
  1656 const int DS_REASON_MASK   = DataLayout::trap_mask >> 1;
  1657 const int DS_RECOMPILE_BIT = DataLayout::trap_mask - DS_REASON_MASK;
  1659 //---------------------------trap_state_reason---------------------------------
  1660 Deoptimization::DeoptReason
  1661 Deoptimization::trap_state_reason(int trap_state) {
  1662   // This assert provides the link between the width of DataLayout::trap_bits
  1663   // and the encoding of "recorded" reasons.  It ensures there are enough
  1664   // bits to store all needed reasons in the per-BCI MDO profile.
  1665   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
  1666   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
  1667   trap_state -= recompile_bit;
  1668   if (trap_state == DS_REASON_MASK) {
  1669     return Reason_many;
  1670   } else {
  1671     assert((int)Reason_none == 0, "state=0 => Reason_none");
  1672     return (DeoptReason)trap_state;
  1675 //-------------------------trap_state_has_reason-------------------------------
  1676 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
  1677   assert(reason_is_recorded_per_bytecode((DeoptReason)reason), "valid reason");
  1678   assert(DS_REASON_MASK >= Reason_RECORDED_LIMIT, "enough bits");
  1679   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
  1680   trap_state -= recompile_bit;
  1681   if (trap_state == DS_REASON_MASK) {
  1682     return -1;  // true, unspecifically (bottom of state lattice)
  1683   } else if (trap_state == reason) {
  1684     return 1;   // true, definitely
  1685   } else if (trap_state == 0) {
  1686     return 0;   // false, definitely (top of state lattice)
  1687   } else {
  1688     return 0;   // false, definitely
  1691 //-------------------------trap_state_add_reason-------------------------------
  1692 int Deoptimization::trap_state_add_reason(int trap_state, int reason) {
  1693   assert(reason_is_recorded_per_bytecode((DeoptReason)reason) || reason == Reason_many, "valid reason");
  1694   int recompile_bit = (trap_state & DS_RECOMPILE_BIT);
  1695   trap_state -= recompile_bit;
  1696   if (trap_state == DS_REASON_MASK) {
  1697     return trap_state + recompile_bit;     // already at state lattice bottom
  1698   } else if (trap_state == reason) {
  1699     return trap_state + recompile_bit;     // the condition is already true
  1700   } else if (trap_state == 0) {
  1701     return reason + recompile_bit;          // no condition has yet been true
  1702   } else {
  1703     return DS_REASON_MASK + recompile_bit;  // fall to state lattice bottom
  1706 //-----------------------trap_state_is_recompiled------------------------------
  1707 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
  1708   return (trap_state & DS_RECOMPILE_BIT) != 0;
  1710 //-----------------------trap_state_set_recompiled-----------------------------
  1711 int Deoptimization::trap_state_set_recompiled(int trap_state, bool z) {
  1712   if (z)  return trap_state |  DS_RECOMPILE_BIT;
  1713   else    return trap_state & ~DS_RECOMPILE_BIT;
  1715 //---------------------------format_trap_state---------------------------------
  1716 // This is used for debugging and diagnostics, including hotspot.log output.
  1717 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
  1718                                               int trap_state) {
  1719   DeoptReason reason      = trap_state_reason(trap_state);
  1720   bool        recomp_flag = trap_state_is_recompiled(trap_state);
  1721   // Re-encode the state from its decoded components.
  1722   int decoded_state = 0;
  1723   if (reason_is_recorded_per_bytecode(reason) || reason == Reason_many)
  1724     decoded_state = trap_state_add_reason(decoded_state, reason);
  1725   if (recomp_flag)
  1726     decoded_state = trap_state_set_recompiled(decoded_state, recomp_flag);
  1727   // If the state re-encodes properly, format it symbolically.
  1728   // Because this routine is used for debugging and diagnostics,
  1729   // be robust even if the state is a strange value.
  1730   size_t len;
  1731   if (decoded_state != trap_state) {
  1732     // Random buggy state that doesn't decode??
  1733     len = jio_snprintf(buf, buflen, "#%d", trap_state);
  1734   } else {
  1735     len = jio_snprintf(buf, buflen, "%s%s",
  1736                        trap_reason_name(reason),
  1737                        recomp_flag ? " recompiled" : "");
  1739   if (len >= buflen)
  1740     buf[buflen-1] = '\0';
  1741   return buf;
  1745 //--------------------------------statics--------------------------------------
  1746 Deoptimization::DeoptAction Deoptimization::_unloaded_action
  1747   = Deoptimization::Action_reinterpret;
  1748 const char* Deoptimization::_trap_reason_name[Reason_LIMIT] = {
  1749   // Note:  Keep this in sync. with enum DeoptReason.
  1750   "none",
  1751   "null_check",
  1752   "null_assert",
  1753   "range_check",
  1754   "class_check",
  1755   "array_check",
  1756   "intrinsic",
  1757   "bimorphic",
  1758   "unloaded",
  1759   "uninitialized",
  1760   "unreached",
  1761   "unhandled",
  1762   "constraint",
  1763   "div0_check",
  1764   "age",
  1765   "predicate"
  1766 };
  1767 const char* Deoptimization::_trap_action_name[Action_LIMIT] = {
  1768   // Note:  Keep this in sync. with enum DeoptAction.
  1769   "none",
  1770   "maybe_recompile",
  1771   "reinterpret",
  1772   "make_not_entrant",
  1773   "make_not_compilable"
  1774 };
  1776 const char* Deoptimization::trap_reason_name(int reason) {
  1777   if (reason == Reason_many)  return "many";
  1778   if ((uint)reason < Reason_LIMIT)
  1779     return _trap_reason_name[reason];
  1780   static char buf[20];
  1781   sprintf(buf, "reason%d", reason);
  1782   return buf;
  1784 const char* Deoptimization::trap_action_name(int action) {
  1785   if ((uint)action < Action_LIMIT)
  1786     return _trap_action_name[action];
  1787   static char buf[20];
  1788   sprintf(buf, "action%d", action);
  1789   return buf;
  1792 // This is used for debugging and diagnostics, including hotspot.log output.
  1793 const char* Deoptimization::format_trap_request(char* buf, size_t buflen,
  1794                                                 int trap_request) {
  1795   jint unloaded_class_index = trap_request_index(trap_request);
  1796   const char* reason = trap_reason_name(trap_request_reason(trap_request));
  1797   const char* action = trap_action_name(trap_request_action(trap_request));
  1798   size_t len;
  1799   if (unloaded_class_index < 0) {
  1800     len = jio_snprintf(buf, buflen, "reason='%s' action='%s'",
  1801                        reason, action);
  1802   } else {
  1803     len = jio_snprintf(buf, buflen, "reason='%s' action='%s' index='%d'",
  1804                        reason, action, unloaded_class_index);
  1806   if (len >= buflen)
  1807     buf[buflen-1] = '\0';
  1808   return buf;
  1811 juint Deoptimization::_deoptimization_hist
  1812         [Deoptimization::Reason_LIMIT]
  1813     [1 + Deoptimization::Action_LIMIT]
  1814         [Deoptimization::BC_CASE_LIMIT]
  1815   = {0};
  1817 enum {
  1818   LSB_BITS = 8,
  1819   LSB_MASK = right_n_bits(LSB_BITS)
  1820 };
  1822 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
  1823                                        Bytecodes::Code bc) {
  1824   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
  1825   assert(action >= 0 && action < Action_LIMIT, "oob");
  1826   _deoptimization_hist[Reason_none][0][0] += 1;  // total
  1827   _deoptimization_hist[reason][0][0]      += 1;  // per-reason total
  1828   juint* cases = _deoptimization_hist[reason][1+action];
  1829   juint* bc_counter_addr = NULL;
  1830   juint  bc_counter      = 0;
  1831   // Look for an unused counter, or an exact match to this BC.
  1832   if (bc != Bytecodes::_illegal) {
  1833     for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
  1834       juint* counter_addr = &cases[bc_case];
  1835       juint  counter = *counter_addr;
  1836       if ((counter == 0 && bc_counter_addr == NULL)
  1837           || (Bytecodes::Code)(counter & LSB_MASK) == bc) {
  1838         // this counter is either free or is already devoted to this BC
  1839         bc_counter_addr = counter_addr;
  1840         bc_counter = counter | bc;
  1844   if (bc_counter_addr == NULL) {
  1845     // Overflow, or no given bytecode.
  1846     bc_counter_addr = &cases[BC_CASE_LIMIT-1];
  1847     bc_counter = (*bc_counter_addr & ~LSB_MASK);  // clear LSB
  1849   *bc_counter_addr = bc_counter + (1 << LSB_BITS);
  1852 jint Deoptimization::total_deoptimization_count() {
  1853   return _deoptimization_hist[Reason_none][0][0];
  1856 jint Deoptimization::deoptimization_count(DeoptReason reason) {
  1857   assert(reason >= 0 && reason < Reason_LIMIT, "oob");
  1858   return _deoptimization_hist[reason][0][0];
  1861 void Deoptimization::print_statistics() {
  1862   juint total = total_deoptimization_count();
  1863   juint account = total;
  1864   if (total != 0) {
  1865     ttyLocker ttyl;
  1866     if (xtty != NULL)  xtty->head("statistics type='deoptimization'");
  1867     tty->print_cr("Deoptimization traps recorded:");
  1868     #define PRINT_STAT_LINE(name, r) \
  1869       tty->print_cr("  %4d (%4.1f%%) %s", (int)(r), ((r) * 100.0) / total, name);
  1870     PRINT_STAT_LINE("total", total);
  1871     // For each non-zero entry in the histogram, print the reason,
  1872     // the action, and (if specifically known) the type of bytecode.
  1873     for (int reason = 0; reason < Reason_LIMIT; reason++) {
  1874       for (int action = 0; action < Action_LIMIT; action++) {
  1875         juint* cases = _deoptimization_hist[reason][1+action];
  1876         for (int bc_case = 0; bc_case < BC_CASE_LIMIT; bc_case++) {
  1877           juint counter = cases[bc_case];
  1878           if (counter != 0) {
  1879             char name[1*K];
  1880             Bytecodes::Code bc = (Bytecodes::Code)(counter & LSB_MASK);
  1881             if (bc_case == BC_CASE_LIMIT && (int)bc == 0)
  1882               bc = Bytecodes::_illegal;
  1883             sprintf(name, "%s/%s/%s",
  1884                     trap_reason_name(reason),
  1885                     trap_action_name(action),
  1886                     Bytecodes::is_defined(bc)? Bytecodes::name(bc): "other");
  1887             juint r = counter >> LSB_BITS;
  1888             tty->print_cr("  %40s: " UINT32_FORMAT " (%.1f%%)", name, r, (r * 100.0) / total);
  1889             account -= r;
  1894     if (account != 0) {
  1895       PRINT_STAT_LINE("unaccounted", account);
  1897     #undef PRINT_STAT_LINE
  1898     if (xtty != NULL)  xtty->tail("statistics");
  1901 #else // COMPILER2 || SHARK
  1904 // Stubs for C1 only system.
  1905 bool Deoptimization::trap_state_is_recompiled(int trap_state) {
  1906   return false;
  1909 const char* Deoptimization::trap_reason_name(int reason) {
  1910   return "unknown";
  1913 void Deoptimization::print_statistics() {
  1914   // no output
  1917 void
  1918 Deoptimization::update_method_data_from_interpreter(methodDataHandle trap_mdo, int trap_bci, int reason) {
  1919   // no udpate
  1922 int Deoptimization::trap_state_has_reason(int trap_state, int reason) {
  1923   return 0;
  1926 void Deoptimization::gather_statistics(DeoptReason reason, DeoptAction action,
  1927                                        Bytecodes::Code bc) {
  1928   // no update
  1931 const char* Deoptimization::format_trap_state(char* buf, size_t buflen,
  1932                                               int trap_state) {
  1933   jio_snprintf(buf, buflen, "#%d", trap_state);
  1934   return buf;
  1937 #endif // COMPILER2 || SHARK

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