1 /*

     2  * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #include "precompiled.hpp"

    26 #include "interpreter/bytecodeStream.hpp"

    27 #include "interpreter/bytecodes.hpp"

    28 #include "interpreter/interpreter.hpp"

    29 #include "interpreter/rewriter.hpp"

    30 #include "logging/log.hpp"

    31 #include "memory/metadataFactory.hpp"

    32 #include "memory/metaspaceClosure.hpp"

    33 #include "memory/resourceArea.hpp"

    34 #include "memory/universe.inline.hpp"

    35 #include "oops/cpCache.hpp"

    36 #include "oops/objArrayOop.inline.hpp"

    37 #include "oops/oop.inline.hpp"

    38 #include "prims/methodHandles.hpp"

    39 #include "runtime/atomic.hpp"

    40 #include "runtime/handles.inline.hpp"

    41 #include "runtime/orderAccess.inline.hpp"

    42 #include "utilities/macros.hpp"

    43 

    44 // Implementation of ConstantPoolCacheEntry

    45 

    46 void ConstantPoolCacheEntry::initialize_entry(int index) {

    47   assert(0 < index && index < 0x10000, "sanity check");

    48   _indices = index;

    49   _f1 = NULL;

    50   _f2 = _flags = 0;

    51   assert(constant_pool_index() == index, "");

    52 }

    53 

    54 void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) {

    55   assert((_indices & (~cp_index_mask)) == 0, "sanity");

    56   assert(_f1 == NULL, "sanity");

    57   assert(_flags == 0, "sanity");

    58   if (!f2_used) {

    59     assert(_f2 == 0, "sanity");

    60   }

    61 }

    62 

    63 void ConstantPoolCacheEntry::reinitialize(bool f2_used) {

    64   _indices &= cp_index_mask;

    65   _f1 = NULL;

    66   _flags = 0;

    67   if (!f2_used) {

    68     _f2 = 0;

    69   }

    70 }

    71 

    72 int ConstantPoolCacheEntry::make_flags(TosState state,

    73                                        int option_bits,

    74                                        int field_index_or_method_params) {

    75   assert(state < number_of_states, "Invalid state in make_flags");

    76   int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;

    77   // Preserve existing flag bit values

    78   // The low bits are a field offset, or else the method parameter size.

    79 #ifdef ASSERT

    80   TosState old_state = flag_state();

    81   assert(old_state == (TosState)0 || old_state == state,

    82          "inconsistent cpCache flags state");

    83 #endif

    84   return (_flags | f) ;

    85 }

    86 

    87 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {

    88 #ifdef ASSERT

    89   // Read once.

    90   volatile Bytecodes::Code c = bytecode_1();

    91   assert(c == 0 || c == code || code == 0, "update must be consistent");

    92 #endif

    93   // Need to flush pending stores here before bytecode is written.

    94   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_1_shift));

    95 }

    96 

    97 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {

    98 #ifdef ASSERT

    99   // Read once.

   100   volatile Bytecodes::Code c = bytecode_2();

   101   assert(c == 0 || c == code || code == 0, "update must be consistent");

   102 #endif

   103   // Need to flush pending stores here before bytecode is written.

   104   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << bytecode_2_shift));

   105 }

   106 

   107 // Sets f1, ordering with previous writes.

   108 void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {

   109   assert(f1 != NULL, "");

   110   OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);

   111 }

   112 

   113 // Sets flags, but only if the value was previously zero.

   114 bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {

   115   intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);

   116   return (result == 0);

   117 }

   118 

   119 // Note that concurrent update of both bytecodes can leave one of them

   120 // reset to zero.  This is harmless; the interpreter will simply re-resolve

   121 // the damaged entry.  More seriously, the memory synchronization is needed

   122 // to flush other fields (f1, f2) completely to memory before the bytecodes

   123 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.

   124 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,

   125                                        Bytecodes::Code put_code,

   126                                        Klass* field_holder,

   127                                        int field_index,

   128                                        int field_offset,

   129                                        TosState field_type,

   130                                        bool is_final,

   131                                        bool is_volatile,

   132                                        Klass* root_klass) {

   133   set_f1(field_holder);

   134   set_f2(field_offset);

   135   assert((field_index & field_index_mask) == field_index,

   136          "field index does not fit in low flag bits");

   137   set_field_flags(field_type,

   138                   ((is_volatile ? 1 : 0) << is_volatile_shift) |

   139                   ((is_final    ? 1 : 0) << is_final_shift),

   140                   field_index);

   141   set_bytecode_1(get_code);

   142   set_bytecode_2(put_code);

   143   NOT_PRODUCT(verify(tty));

   144 }

   145 

   146 void ConstantPoolCacheEntry::set_parameter_size(int value) {

   147   // This routine is called only in corner cases where the CPCE is not yet initialized.

   148   // See AbstractInterpreter::deopt_continue_after_entry.

   149   assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,

   150          "size must not change: parameter_size=%d, value=%d", parameter_size(), value);

   151   // Setting the parameter size by itself is only safe if the

   152   // current value of _flags is 0, otherwise another thread may have

   153   // updated it and we don't want to overwrite that value.  Don't

   154   // bother trying to update it once it's nonzero but always make

   155   // sure that the final parameter size agrees with what was passed.

   156   if (_flags == 0) {

   157     Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);

   158   }

   159   guarantee(parameter_size() == value,

   160             "size must not change: parameter_size=%d, value=%d", parameter_size(), value);

   161 }

   162 

   163 void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,

   164                                                        const methodHandle& method,

   165                                                        int vtable_index,

   166                                                        bool sender_is_interface) {

   167   bool is_vtable_call = (vtable_index >= 0);  // FIXME: split this method on this boolean

   168   assert(method->interpreter_entry() != NULL, "should have been set at this point");

   169   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");

   170 

   171   int byte_no = -1;

   172   bool change_to_virtual = false;

   173 

   174   switch (invoke_code) {

   175     case Bytecodes::_invokeinterface:

   176       // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface

   177       // instruction somehow links to a non-interface method (in Object).

   178       // In that case, the method has no itable index and must be invoked as a virtual.

   179       // Set a flag to keep track of this corner case.

   180       change_to_virtual = true;

   181 

   182       // ...and fall through as if we were handling invokevirtual:

   183     case Bytecodes::_invokevirtual:

   184       {

   185         if (!is_vtable_call) {

   186           assert(method->can_be_statically_bound(), "");

   187           // set_f2_as_vfinal_method checks if is_vfinal flag is true.

   188           set_method_flags(as_TosState(method->result_type()),

   189                            (                             1      << is_vfinal_shift) |

   190                            ((method->is_final_method() ? 1 : 0) << is_final_shift)  |

   191                            ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),

   192                            method()->size_of_parameters());

   193           set_f2_as_vfinal_method(method());

   194         } else {

   195           assert(!method->can_be_statically_bound(), "");

   196           assert(vtable_index >= 0, "valid index");

   197           assert(!method->is_final_method(), "sanity");

   198           set_method_flags(as_TosState(method->result_type()),

   199                            ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),

   200                            method()->size_of_parameters());

   201           set_f2(vtable_index);

   202         }

   203         byte_no = 2;

   204         break;

   205       }

   206 

   207     case Bytecodes::_invokespecial:

   208     case Bytecodes::_invokestatic:

   209       assert(!is_vtable_call, "");

   210       // Note:  Read and preserve the value of the is_vfinal flag on any

   211       // invokevirtual bytecode shared with this constant pool cache entry.

   212       // It is cheap and safe to consult is_vfinal() at all times.

   213       // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.

   214       set_method_flags(as_TosState(method->result_type()),

   215                        ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |

   216                        ((method->is_final_method() ? 1 : 0) << is_final_shift),

   217                        method()->size_of_parameters());

   218       set_f1(method());

   219       byte_no = 1;

   220       break;

   221     default:

   222       ShouldNotReachHere();

   223       break;

   224   }

   225 

   226   // Note:  byte_no also appears in TemplateTable::resolve.

   227   if (byte_no == 1) {

   228     assert(invoke_code != Bytecodes::_invokevirtual &&

   229            invoke_code != Bytecodes::_invokeinterface, "");

   230     // Don't mark invokespecial to method as resolved if sender is an interface.  The receiver

   231     // has to be checked that it is a subclass of the current class every time this bytecode

   232     // is executed.

   233     if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface ||

   234         method->name() == vmSymbols::object_initializer_name()) {

   235     set_bytecode_1(invoke_code);

   236     }

   237   } else if (byte_no == 2)  {

   238     if (change_to_virtual) {

   239       assert(invoke_code == Bytecodes::_invokeinterface, "");

   240       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!

   241       //

   242       // Workaround for the case where we encounter an invokeinterface, but we

   243       // should really have an _invokevirtual since the resolved method is a

   244       // virtual method in java.lang.Object. This is a corner case in the spec

   245       // but is presumably legal. javac does not generate this code.

   246       //

   247       // We set bytecode_1() to _invokeinterface, because that is the

   248       // bytecode # used by the interpreter to see if it is resolved.

   249       // We set bytecode_2() to _invokevirtual.

   250       // See also interpreterRuntime.cpp. (8/25/2000)

   251       // Only set resolved for the invokeinterface case if method is public.

   252       // Otherwise, the method needs to be reresolved with caller for each

   253       // interface call.

   254       if (method->is_public()) set_bytecode_1(invoke_code);

   255     } else {

   256       assert(invoke_code == Bytecodes::_invokevirtual, "");

   257     }

   258     // set up for invokevirtual, even if linking for invokeinterface also:

   259     set_bytecode_2(Bytecodes::_invokevirtual);

   260   } else {

   261     ShouldNotReachHere();

   262   }

   263   NOT_PRODUCT(verify(tty));

   264 }

   265 

   266 void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,

   267                                              bool sender_is_interface) {

   268   int index = Method::nonvirtual_vtable_index;

   269   // index < 0; FIXME: inline and customize set_direct_or_vtable_call

   270   set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);

   271 }

   272 

   273 void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {

   274   // either the method is a miranda or its holder should accept the given index

   275   assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");

   276   // index >= 0; FIXME: inline and customize set_direct_or_vtable_call

   277   set_direct_or_vtable_call(invoke_code, method, index, false);

   278 }

   279 

   280 void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {

   281   assert(method->method_holder()->verify_itable_index(index), "");

   282   assert(invoke_code == Bytecodes::_invokeinterface, "");

   283   InstanceKlass* interf = method->method_holder();

   284   assert(interf->is_interface(), "must be an interface");

   285   assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");

   286   set_f1(interf);

   287   set_f2(index);

   288   set_method_flags(as_TosState(method->result_type()),

   289                    0,  // no option bits

   290                    method()->size_of_parameters());

   291   set_bytecode_1(Bytecodes::_invokeinterface);

   292 }

   293 

   294 

   295 void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {

   296   set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);

   297 }

   298 

   299 void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {

   300   set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);

   301 }

   302 

   303 void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,

   304                                                       Bytecodes::Code invoke_code,

   305                                                       const CallInfo &call_info) {

   306   // NOTE: This CPCE can be the subject of data races.

   307   // There are three words to update: flags, refs[f2], f1 (in that order).

   308   // Writers must store all other values before f1.

   309   // Readers must test f1 first for non-null before reading other fields.

   310   // Competing writers must acquire exclusive access via a lock.

   311   // A losing writer waits on the lock until the winner writes f1 and leaves

   312   // the lock, so that when the losing writer returns, he can use the linked

   313   // cache entry.

   314 

   315   objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());

   316   // Use the resolved_references() lock for this cpCache entry.

   317   // resolved_references are created for all classes with Invokedynamic, MethodHandle

   318   // or MethodType constant pool cache entries.

   319   assert(resolved_references() != NULL,

   320          "a resolved_references array should have been created for this class");

   321   ObjectLocker ol(resolved_references, Thread::current());

   322   if (!is_f1_null()) {

   323     return;

   324   }

   325 

   326   const methodHandle adapter = call_info.resolved_method();

   327   const Handle appendix      = call_info.resolved_appendix();

   328   const Handle method_type   = call_info.resolved_method_type();

   329   const bool has_appendix    = appendix.not_null();

   330   const bool has_method_type = method_type.not_null();

   331 

   332   // Write the flags.

   333   set_method_flags(as_TosState(adapter->result_type()),

   334                    ((has_appendix    ? 1 : 0) << has_appendix_shift   ) |

   335                    ((has_method_type ? 1 : 0) << has_method_type_shift) |

   336                    (                   1      << is_final_shift       ),

   337                    adapter->size_of_parameters());

   338 

   339   if (TraceInvokeDynamic) {

   340     ttyLocker ttyl;

   341     tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",

   342                   invoke_code,

   343                   p2i(appendix()),    (has_appendix    ? "" : " (unused)"),

   344                   p2i(method_type()), (has_method_type ? "" : " (unused)"),

   345                   p2i(adapter()));

   346     adapter->print();

   347     if (has_appendix)  appendix()->print();

   348   }

   349 

   350   // Method handle invokes and invokedynamic sites use both cp cache words.

   351   // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.

   352   // In the general case, this could be the call site's MethodType,

   353   // for use with java.lang.Invokers.checkExactType, or else a CallSite object.

   354   // f1 contains the adapter method which manages the actual call.

   355   // In the general case, this is a compiled LambdaForm.

   356   // (The Java code is free to optimize these calls by binding other

   357   // sorts of methods and appendices to call sites.)

   358   // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.

   359   // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.

   360   // Even with the appendix, the method will never take more than 255 parameter slots.

   361   //

   362   // This means that given a call site like (List)mh.invoke("foo"),

   363   // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',

   364   // not '(Ljava/lang/String;)Ljava/util/List;'.

   365   // The fact that String and List are involved is encoded in the MethodType in refs[f2].

   366   // This allows us to create fewer Methods, while keeping type safety.

   367   //

   368 

   369   // Store appendix, if any.

   370   if (has_appendix) {

   371     const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;

   372     assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");

   373     assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");

   374     resolved_references->obj_at_put(appendix_index, appendix());

   375   }

   376 

   377   // Store MethodType, if any.

   378   if (has_method_type) {

   379     const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;

   380     assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");

   381     assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");

   382     resolved_references->obj_at_put(method_type_index, method_type());

   383   }

   384 

   385   release_set_f1(adapter());  // This must be the last one to set (see NOTE above)!

   386 

   387   // The interpreter assembly code does not check byte_2,

   388   // but it is used by is_resolved, method_if_resolved, etc.

   389   set_bytecode_1(invoke_code);

   390   NOT_PRODUCT(verify(tty));

   391   if (TraceInvokeDynamic) {

   392     ttyLocker ttyl;

   393     this->print(tty, 0);

   394   }

   395 }

   396 

   397 Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {

   398   // Decode the action of set_method and set_interface_call

   399   Bytecodes::Code invoke_code = bytecode_1();

   400   if (invoke_code != (Bytecodes::Code)0) {

   401     Metadata* f1 = f1_ord();

   402     if (f1 != NULL) {

   403       switch (invoke_code) {

   404       case Bytecodes::_invokeinterface:

   405         assert(f1->is_klass(), "");

   406         return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());

   407       case Bytecodes::_invokestatic:

   408       case Bytecodes::_invokespecial:

   409         assert(!has_appendix(), "");

   410       case Bytecodes::_invokehandle:

   411       case Bytecodes::_invokedynamic:

   412         assert(f1->is_method(), "");

   413         return (Method*)f1;

   414       default:

   415         break;

   416       }

   417     }

   418   }

   419   invoke_code = bytecode_2();

   420   if (invoke_code != (Bytecodes::Code)0) {

   421     switch (invoke_code) {

   422     case Bytecodes::_invokevirtual:

   423       if (is_vfinal()) {

   424         // invokevirtual

   425         Method* m = f2_as_vfinal_method();

   426         assert(m->is_method(), "");

   427         return m;

   428       } else {

   429         int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());

   430         if (cpool->tag_at(holder_index).is_klass()) {

   431           Klass* klass = cpool->resolved_klass_at(holder_index);

   432           return klass->method_at_vtable(f2_as_index());

   433         }

   434       }

   435       break;

   436     default:

   437       break;

   438     }

   439   }

   440   return NULL;

   441 }

   442 

   443 

   444 oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {

   445   if (!has_appendix())

   446     return NULL;

   447   const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;

   448   objArrayOop resolved_references = cpool->resolved_references();

   449   return resolved_references->obj_at(ref_index);

   450 }

   451 

   452 

   453 oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {

   454   if (!has_method_type())

   455     return NULL;

   456   const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;

   457   objArrayOop resolved_references = cpool->resolved_references();

   458   return resolved_references->obj_at(ref_index);

   459 }

   460 

   461 

   462 #if INCLUDE_JVMTI

   463 // RedefineClasses() API support:

   464 // If this ConstantPoolCacheEntry refers to old_method then update it

   465 // to refer to new_method.

   466 bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,

   467        Method* new_method, bool * trace_name_printed) {

   468 

   469   if (is_vfinal()) {

   470     // virtual and final so _f2 contains method ptr instead of vtable index

   471     if (f2_as_vfinal_method() == old_method) {

   472       // match old_method so need an update

   473       // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values

   474       _f2 = (intptr_t)new_method;

   475       if (log_is_enabled(Info, redefine, class, update)) {

   476         ResourceMark rm;

   477         if (!(*trace_name_printed)) {

   478           log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());

   479           *trace_name_printed = true;

   480         }

   481         log_debug(redefine, class, update, constantpool)

   482           ("cpc vf-entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());

   483       }

   484       return true;

   485     }

   486 

   487     // f1() is not used with virtual entries so bail out

   488     return false;

   489   }

   490 

   491   if (_f1 == NULL) {

   492     // NULL f1() means this is a virtual entry so bail out

   493     // We are assuming that the vtable index does not need change.

   494     return false;

   495   }

   496 

   497   if (_f1 == old_method) {

   498     _f1 = new_method;

   499     if (log_is_enabled(Info, redefine, class, update)) {

   500       ResourceMark rm;

   501       if (!(*trace_name_printed)) {

   502         log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());

   503         *trace_name_printed = true;

   504       }

   505       log_debug(redefine, class, update, constantpool)

   506         ("cpc entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());

   507     }

   508     return true;

   509   }

   510 

   511   return false;

   512 }

   513 

   514 // a constant pool cache entry should never contain old or obsolete methods

   515 bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {

   516   if (is_vfinal()) {

   517     // virtual and final so _f2 contains method ptr instead of vtable index

   518     Metadata* f2 = (Metadata*)_f2;

   519     // Return false if _f2 refers to an old or an obsolete method.

   520     // _f2 == NULL || !_f2->is_method() are just as unexpected here.

   521     return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() &&

   522             !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete());

   523   } else if (_f1 == NULL ||

   524              (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) {

   525     // _f1 == NULL || !_f1->is_method() are OK here

   526     return true;

   527   }

   528   // return false if _f1 refers to a non-deleted old or obsolete method

   529   return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() &&

   530           (f1_as_method()->is_deleted() ||

   531           (!f1_as_method()->is_old() && !f1_as_method()->is_obsolete())));

   532 }

   533 

   534 Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {

   535   if (!is_method_entry()) {

   536     // not a method entry so not interesting by default

   537     return NULL;

   538   }

   539   Method* m = NULL;

   540   if (is_vfinal()) {

   541     // virtual and final so _f2 contains method ptr instead of vtable index

   542     m = f2_as_vfinal_method();

   543   } else if (is_f1_null()) {

   544     // NULL _f1 means this is a virtual entry so also not interesting

   545     return NULL;

   546   } else {

   547     if (!(_f1->is_method())) {

   548       // _f1 can also contain a Klass* for an interface

   549       return NULL;

   550     }

   551     m = f1_as_method();

   552   }

   553   assert(m != NULL && m->is_method(), "sanity check");

   554   if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {

   555     // robustness for above sanity checks or method is not in

   556     // the interesting class

   557     return NULL;

   558   }

   559   // the method is in the interesting class so the entry is interesting

   560   return m;

   561 }

   562 #endif // INCLUDE_JVMTI

   563 

   564 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {

   565   // print separator

   566   if (index == 0) st->print_cr("                 -------------");

   567   // print entry

   568   st->print("%3d  (" PTR_FORMAT ")  ", index, (intptr_t)this);

   569   st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),

   570                constant_pool_index());

   571   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f1);

   572   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f2);

   573   st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_flags);

   574   st->print_cr("                 -------------");

   575 }

   576 

   577 void ConstantPoolCacheEntry::verify(outputStream* st) const {

   578   // not implemented yet

   579 }

   580 

   581 // Implementation of ConstantPoolCache

   582 

   583 ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,

   584                                      const intStack& index_map,

   585                                      const intStack& invokedynamic_index_map,

   586                                      const intStack& invokedynamic_map, TRAPS) {

   587 

   588   const int length = index_map.length() + invokedynamic_index_map.length();

   589   int size = ConstantPoolCache::size(length);

   590 

   591   return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)

   592     ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);

   593 }

   594 

   595 void ConstantPoolCache::initialize(const intArray& inverse_index_map,

   596                                    const intArray& invokedynamic_inverse_index_map,

   597                                    const intArray& invokedynamic_references_map) {

   598   for (int i = 0; i < inverse_index_map.length(); i++) {

   599     ConstantPoolCacheEntry* e = entry_at(i);

   600     int original_index = inverse_index_map.at(i);

   601     e->initialize_entry(original_index);

   602     assert(entry_at(i) == e, "sanity");

   603   }

   604 

   605   // Append invokedynamic entries at the end

   606   int invokedynamic_offset = inverse_index_map.length();

   607   for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {

   608     int offset = i + invokedynamic_offset;

   609     ConstantPoolCacheEntry* e = entry_at(offset);

   610     int original_index = invokedynamic_inverse_index_map.at(i);

   611     e->initialize_entry(original_index);

   612     assert(entry_at(offset) == e, "sanity");

   613   }

   614 

   615   for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {

   616     const int cpci = invokedynamic_references_map.at(ref);

   617     if (cpci >= 0) {

   618 #ifdef ASSERT

   619       // invokedynamic and invokehandle have more entries; check if they

   620       // all point to the same constant pool cache entry.

   621       for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {

   622         const int cpci_next = invokedynamic_references_map.at(ref + entry);

   623         assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);

   624       }

   625 #endif

   626       entry_at(cpci)->initialize_resolved_reference_index(ref);

   627       ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1;  // skip extra entries

   628     }

   629   }

   630 }

   631 

   632 void ConstantPoolCache::verify_just_initialized() {

   633   DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));

   634 }

   635 

   636 void ConstantPoolCache::remove_unshareable_info() {

   637   walk_entries_for_initialization(/*check_only = */ false);

   638 }

   639 

   640 void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {

   641   assert(DumpSharedSpaces, "sanity");

   642   // When dumping the archive, we want to clean up the ConstantPoolCache

   643   // to remove any effect of linking due to the execution of Java code --

   644   // each ConstantPoolCacheEntry will have the same contents as if

   645   // ConstantPoolCache::initialize has just returned:

   646   //

   647   // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.

   648   // - We keep the "f2" field for entries used by invokedynamic and invokehandle

   649   // - All other bits in the entries are cleared to zero.

   650   ResourceMark rm;

   651 

   652   InstanceKlass* ik = constant_pool()->pool_holder();

   653   bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());

   654   memset(f2_used, 0, sizeof(bool) * length());

   655 

   656   // Find all the slots that we need to preserve f2

   657   for (int i = 0; i < ik->methods()->length(); i++) {

   658     Method* m = ik->methods()->at(i);

   659     RawBytecodeStream bcs(m);

   660     while (!bcs.is_last_bytecode()) {

   661       Bytecodes::Code opcode = bcs.raw_next();

   662       switch (opcode) {

   663       case Bytecodes::_invokedynamic: {

   664           int index = Bytes::get_native_u4(bcs.bcp() + 1);

   665           int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);

   666           f2_used[cp_cache_index] = 1;

   667         }

   668         break;

   669       case Bytecodes::_invokehandle: {

   670           int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);

   671           f2_used[cp_cache_index] = 1;

   672         }

   673         break;

   674       default:

   675         break;

   676       }

   677     }

   678   }

   679 

   680   if (check_only) {

   681     DEBUG_ONLY(

   682       for (int i=0; i<length(); i++) {

   683         entry_at(i)->verify_just_initialized(f2_used[i]);

   684       })

   685   } else {

   686     for (int i=0; i<length(); i++) {

   687       entry_at(i)->reinitialize(f2_used[i]);

   688     }

   689   }

   690 }

   691 

   692 void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {

   693   assert(!is_shared(), "shared caches are not deallocated");

   694   data->remove_handle(_resolved_references);

   695   set_resolved_references(NULL);

   696   MetadataFactory::free_array<u2>(data, _reference_map);

   697   set_reference_map(NULL);

   698 }

   699 

   700 #if INCLUDE_CDS_JAVA_HEAP

   701 oop ConstantPoolCache::archived_references() {

   702   assert(UseSharedSpaces, "UseSharedSpaces expected.");

   703   return oopDesc::decode_heap_oop(_archived_references);

   704 }

   705 

   706 void ConstantPoolCache::set_archived_references(oop o) {

   707   assert(DumpSharedSpaces, "called only during runtime");

   708   _archived_references = oopDesc::encode_heap_oop(o);

   709 }

   710 #endif

   711 

   712 #if INCLUDE_JVMTI

   713 // RedefineClasses() API support:

   714 // If any entry of this ConstantPoolCache points to any of

   715 // old_methods, replace it with the corresponding new_method.

   716 void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {

   717   for (int i = 0; i < length(); i++) {

   718     ConstantPoolCacheEntry* entry = entry_at(i);

   719     Method* old_method = entry->get_interesting_method_entry(holder);

   720     if (old_method == NULL || !old_method->is_old()) {

   721       continue; // skip uninteresting entries

   722     }

   723     if (old_method->is_deleted()) {

   724       // clean up entries with deleted methods

   725       entry->initialize_entry(entry->constant_pool_index());

   726       continue;

   727     }

   728     Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());

   729 

   730     assert(new_method != NULL, "method_with_idnum() should not be NULL");

   731     assert(old_method != new_method, "sanity check");

   732 

   733     entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);

   734   }

   735 }

   736 

   737 // the constant pool cache should never contain old or obsolete methods

   738 bool ConstantPoolCache::check_no_old_or_obsolete_entries() {

   739   for (int i = 1; i < length(); i++) {

   740     if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&

   741         !entry_at(i)->check_no_old_or_obsolete_entries()) {

   742       return false;

   743     }

   744   }

   745   return true;

   746 }

   747 

   748 void ConstantPoolCache::dump_cache() {

   749   for (int i = 1; i < length(); i++) {

   750     if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {

   751       entry_at(i)->print(tty, i);

   752     }

   753   }

   754 }

   755 #endif // INCLUDE_JVMTI

   756 

   757 void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {

   758   log_trace(cds)("Iter(ConstantPoolCache): %p", this);

   759   it->push(&_constant_pool);

   760   it->push(&_reference_map);

   761 }

   762 

   763 // Printing

   764 

   765 void ConstantPoolCache::print_on(outputStream* st) const {

   766   assert(is_constantPoolCache(), "obj must be constant pool cache");

   767   st->print_cr("%s", internal_name());

   768   // print constant pool cache entries

   769   for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);

   770 }

   771 

   772 void ConstantPoolCache::print_value_on(outputStream* st) const {

   773   assert(is_constantPoolCache(), "obj must be constant pool cache");

   774   st->print("cache [%d]", length());

   775   print_address_on(st);

   776   st->print(" for ");

   777   constant_pool()->print_value_on(st);

   778 }

   779 

   780 

   781 // Verification

   782 

   783 void ConstantPoolCache::verify_on(outputStream* st) {

   784   guarantee(is_constantPoolCache(), "obj must be constant pool cache");

   785   // print constant pool cache entries

   786   for (int i = 0; i < length(); i++) entry_at(i)->verify(st);

   787 }