1 /*

     2  * Copyright 1998-2006 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  *

    23  */

    24 

    25 #include "incls/_precompiled.incl"

    26 #include "incls/_cpCacheOop.cpp.incl"

    27 

    28 

    29 // Implememtation of ConstantPoolCacheEntry

    30 

    31 void ConstantPoolCacheEntry::set_initial_state(int index) {

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

    33   _indices = index;

    34 }

    35 

    36 

    37 int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final,

    38                     bool is_vfinal, bool is_volatile,

    39                     bool is_method_interface, bool is_method) {

    40   int f = state;

    41 

    42   assert( state < number_of_states, "Invalid state in as_flags");

    43 

    44   f <<= 1;

    45   if (is_final) f |= 1;

    46   f <<= 1;

    47   if (is_vfinal) f |= 1;

    48   f <<= 1;

    49   if (is_volatile) f |= 1;

    50   f <<= 1;

    51   if (is_method_interface) f |= 1;

    52   f <<= 1;

    53   if (is_method) f |= 1;

    54   f <<= ConstantPoolCacheEntry::hotSwapBit;

    55   // Preserve existing flag bit values

    56 #ifdef ASSERT

    57   int old_state = ((_flags >> tosBits) & 0x0F);

    58   assert(old_state == 0 || old_state == state,

    59          "inconsistent cpCache flags state");

    60 #endif

    61   return (_flags | f) ;

    62 }

    63 

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

    65 #ifdef ASSERT

    66   // Read once.

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

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

    69 #endif

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

    71   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 16));

    72 }

    73 

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

    75 #ifdef ASSERT

    76   // Read once.

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

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

    79 #endif

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

    81   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 24));

    82 }

    83 

    84 #ifdef ASSERT

    85 // It is possible to have two different dummy methodOops created

    86 // when the resolve code for invoke interface executes concurrently

    87 // Hence the assertion below is weakened a bit for the invokeinterface

    88 // case.

    89 bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {

    90   return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==

    91          ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==

    92          ((methodOop)f1)->signature());

    93 }

    94 #endif

    95 

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

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

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

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

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

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

   102                                        Bytecodes::Code put_code,

   103                                        KlassHandle field_holder,

   104                                        int orig_field_index,

   105                                        int field_offset,

   106                                        TosState field_type,

   107                                        bool is_final,

   108                                        bool is_volatile) {

   109   set_f1(field_holder());

   110   set_f2(field_offset);

   111   // The field index is used by jvm/ti and is the index into fields() array

   112   // in holder instanceKlass.  This is scaled by instanceKlass::next_offset.

   113   assert((orig_field_index % instanceKlass::next_offset) == 0, "wierd index");

   114   const int field_index = orig_field_index / instanceKlass::next_offset;

   115   assert(field_index <= field_index_mask,

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

   117   set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |

   118             (field_index & field_index_mask));

   119   set_bytecode_1(get_code);

   120   set_bytecode_2(put_code);

   121   NOT_PRODUCT(verify(tty));

   122 }

   123 

   124 int  ConstantPoolCacheEntry::field_index() const {

   125   return (_flags & field_index_mask) * instanceKlass::next_offset;

   126 }

   127 

   128 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,

   129                                         methodHandle method,

   130                                         int vtable_index) {

   131 

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

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

   134   bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface);

   135 

   136   int byte_no = -1;

   137   bool needs_vfinal_flag = false;

   138   switch (invoke_code) {

   139     case Bytecodes::_invokevirtual:

   140     case Bytecodes::_invokeinterface: {

   141         if (method->can_be_statically_bound()) {

   142           set_f2((intptr_t)method());

   143           needs_vfinal_flag = true;

   144         } else {

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

   146           set_f2(vtable_index);

   147         }

   148         byte_no = 2;

   149         break;

   150     }

   151     case Bytecodes::_invokespecial:

   152       // Preserve the value of the vfinal flag on invokevirtual bytecode

   153       // which may be shared with this constant pool cache entry.

   154       needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal();

   155       // fall through

   156     case Bytecodes::_invokestatic:

   157       set_f1(method());

   158       byte_no = 1;

   159       break;

   160     default:

   161       ShouldNotReachHere();

   162       break;

   163   }

   164 

   165   set_flags(as_flags(as_TosState(method->result_type()),

   166                      method->is_final_method(),

   167                      needs_vfinal_flag,

   168                      false,

   169                      change_to_virtual,

   170                      true)|

   171             method()->size_of_parameters());

   172 

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

   174   if (byte_no == 1) {

   175     set_bytecode_1(invoke_code);

   176   } else if (byte_no == 2)  {

   177     if (change_to_virtual) {

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

   179       //

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

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

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

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

   184       //

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

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

   187       // We set bytecode_2() to _invokevirtual.

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

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

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

   191       // interface call.

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

   193       set_bytecode_2(Bytecodes::_invokevirtual);

   194     } else {

   195       set_bytecode_2(invoke_code);

   196     }

   197   } else {

   198     ShouldNotReachHere();

   199   }

   200   NOT_PRODUCT(verify(tty));

   201 }

   202 

   203 

   204 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {

   205   klassOop interf = method->method_holder();

   206   assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");

   207   set_f1(interf);

   208   set_f2(index);

   209   set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());

   210   set_bytecode_1(Bytecodes::_invokeinterface);

   211 }

   212 

   213 

   214 class LocalOopClosure: public OopClosure {

   215  private:

   216   void (*_f)(oop*);

   217 

   218  public:

   219   LocalOopClosure(void f(oop*))        { _f = f; }

   220   virtual void do_oop(oop* o)          { _f(o); }

   221 };

   222 

   223 

   224 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {

   225   LocalOopClosure blk(f);

   226   oop_iterate(&blk);

   227 }

   228 

   229 

   230 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {

   231   assert(in_words(size()) == 4, "check code below - may need adjustment");

   232   // field[1] is always oop or NULL

   233   blk->do_oop((oop*)&_f1);

   234   if (is_vfinal()) {

   235     blk->do_oop((oop*)&_f2);

   236   }

   237 }

   238 

   239 

   240 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {

   241   assert(in_words(size()) == 4, "check code below - may need adjustment");

   242   // field[1] is always oop or NULL

   243   if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);

   244   if (is_vfinal()) {

   245     if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);

   246   }

   247 }

   248 

   249 

   250 void ConstantPoolCacheEntry::follow_contents() {

   251   assert(in_words(size()) == 4, "check code below - may need adjustment");

   252   // field[1] is always oop or NULL

   253   MarkSweep::mark_and_push((oop*)&_f1);

   254   if (is_vfinal()) {

   255     MarkSweep::mark_and_push((oop*)&_f2);

   256   }

   257 }

   258 

   259 #ifndef SERIALGC

   260 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {

   261   assert(in_words(size()) == 4, "check code below - may need adjustment");

   262   // field[1] is always oop or NULL

   263   PSParallelCompact::mark_and_push(cm, (oop*)&_f1);

   264   if (is_vfinal()) {

   265     PSParallelCompact::mark_and_push(cm, (oop*)&_f2);

   266   }

   267 }

   268 #endif // SERIALGC

   269 

   270 void ConstantPoolCacheEntry::adjust_pointers() {

   271   assert(in_words(size()) == 4, "check code below - may need adjustment");

   272   // field[1] is always oop or NULL

   273   MarkSweep::adjust_pointer((oop*)&_f1);

   274   if (is_vfinal()) {

   275     MarkSweep::adjust_pointer((oop*)&_f2);

   276   }

   277 }

   278 

   279 #ifndef SERIALGC

   280 void ConstantPoolCacheEntry::update_pointers() {

   281   assert(in_words(size()) == 4, "check code below - may need adjustment");

   282   // field[1] is always oop or NULL

   283   PSParallelCompact::adjust_pointer((oop*)&_f1);

   284   if (is_vfinal()) {

   285     PSParallelCompact::adjust_pointer((oop*)&_f2);

   286   }

   287 }

   288 

   289 void ConstantPoolCacheEntry::update_pointers(HeapWord* beg_addr,

   290                                              HeapWord* end_addr) {

   291   assert(in_words(size()) == 4, "check code below - may need adjustment");

   292   // field[1] is always oop or NULL

   293   PSParallelCompact::adjust_pointer((oop*)&_f1, beg_addr, end_addr);

   294   if (is_vfinal()) {

   295     PSParallelCompact::adjust_pointer((oop*)&_f2, beg_addr, end_addr);

   296   }

   297 }

   298 #endif // SERIALGC

   299 

   300 // RedefineClasses() API support:

   301 // If this constantPoolCacheEntry refers to old_method then update it

   302 // to refer to new_method.

   303 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,

   304        methodOop new_method, bool * trace_name_printed) {

   305 

   306   if (is_vfinal()) {

   307     // virtual and final so f2() contains method ptr instead of vtable index

   308     if (f2() == (intptr_t)old_method) {

   309       // match old_method so need an update

   310       _f2 = (intptr_t)new_method;

   311       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

   312         if (!(*trace_name_printed)) {

   313           // RC_TRACE_MESG macro has an embedded ResourceMark

   314           RC_TRACE_MESG(("adjust: name=%s",

   315             Klass::cast(old_method->method_holder())->external_name()));

   316           *trace_name_printed = true;

   317         }

   318         // RC_TRACE macro has an embedded ResourceMark

   319         RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",

   320           new_method->name()->as_C_string(),

   321           new_method->signature()->as_C_string()));

   322       }

   323 

   324       return true;

   325     }

   326 

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

   328     return false;

   329   }

   330 

   331   if ((oop)_f1 == NULL) {

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

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

   334     return false;

   335   }

   336 

   337   if ((oop)_f1 == old_method) {

   338     _f1 = new_method;

   339     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {

   340       if (!(*trace_name_printed)) {

   341         // RC_TRACE_MESG macro has an embedded ResourceMark

   342         RC_TRACE_MESG(("adjust: name=%s",

   343           Klass::cast(old_method->method_holder())->external_name()));

   344         *trace_name_printed = true;

   345       }

   346       // RC_TRACE macro has an embedded ResourceMark

   347       RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",

   348         new_method->name()->as_C_string(),

   349         new_method->signature()->as_C_string()));

   350     }

   351 

   352     return true;

   353   }

   354 

   355   return false;

   356 }

   357 

   358 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {

   359   if (!is_method_entry()) {

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

   361     return false;

   362   }

   363 

   364   methodOop m = NULL;

   365   if (is_vfinal()) {

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

   367     m = (methodOop)_f2;

   368   } else if ((oop)_f1 == NULL) {

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

   370     return false;

   371   } else {

   372     if (!((oop)_f1)->is_method()) {

   373       // _f1 can also contain a klassOop for an interface

   374       return false;

   375     }

   376     m = (methodOop)_f1;

   377   }

   378 

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

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

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

   382     // the interesting class

   383     return false;

   384   }

   385 

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

   387   return true;

   388 }

   389 

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

   391   // print separator

   392   if (index == 0) tty->print_cr("                 -------------");

   393   // print entry

   394   tty->print_cr("%3d  (%08x)  [%02x|%02x|%5d]", index, this, bytecode_2(), bytecode_1(), constant_pool_index());

   395   tty->print_cr("                 [   %08x]", (address)(oop)_f1);

   396   tty->print_cr("                 [   %08x]", _f2);

   397   tty->print_cr("                 [   %08x]", _flags);

   398   tty->print_cr("                 -------------");

   399 }

   400 

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

   402   // not implemented yet

   403 }

   404 

   405 // Implementation of ConstantPoolCache

   406 

   407 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {

   408   assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");

   409   for (int i = 0; i < length(); i++) entry_at(i)->set_initial_state(inverse_index_map[i]);

   410 }

   411 

   412 // RedefineClasses() API support:

   413 // If any entry of this constantPoolCache points to any of

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

   415 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,

   416                                                      int methods_length, bool * trace_name_printed) {

   417 

   418   if (methods_length == 0) {

   419     // nothing to do if there are no methods

   420     return;

   421   }

   422 

   423   // get shorthand for the interesting class

   424   klassOop old_holder = old_methods[0]->method_holder();

   425 

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

   427     if (!entry_at(i)->is_interesting_method_entry(old_holder)) {

   428       // skip uninteresting methods

   429       continue;

   430     }

   431 

   432     // The constantPoolCache contains entries for several different

   433     // things, but we only care about methods. In fact, we only care

   434     // about methods in the same class as the one that contains the

   435     // old_methods. At this point, we have an interesting entry.

   436 

   437     for (int j = 0; j < methods_length; j++) {

   438       methodOop old_method = old_methods[j];

   439       methodOop new_method = new_methods[j];

   440 

   441       if (entry_at(i)->adjust_method_entry(old_method, new_method,

   442           trace_name_printed)) {

   443         // current old_method matched this entry and we updated it so

   444         // break out and get to the next interesting entry if there one

   445         break;

   446       }

   447     }

   448   }

   449 }