src/share/vm/prims/methodComparator.cpp

Fri, 22 Oct 2010 15:59:34 -0400

author
acorn
date
Fri, 22 Oct 2010 15:59:34 -0400
changeset 2233
fa83ab460c54
parent 1957
136b78722a08
child 2268
3b2dea75431e
permissions
-rw-r--r--

6988353: refactor contended sync subsystem
Summary: reduce complexity by factoring synchronizer.cpp
Reviewed-by: dholmes, never, coleenp

     1 /*
     2  * Copyright (c) 2000, 2010, 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 "incls/_precompiled.incl"
    26 # include "incls/_methodComparator.cpp.incl"
    28 BytecodeStream *MethodComparator::_s_old;
    29 BytecodeStream *MethodComparator::_s_new;
    30 constantPoolOop MethodComparator::_old_cp;
    31 constantPoolOop MethodComparator::_new_cp;
    32 BciMap *MethodComparator::_bci_map;
    33 bool MethodComparator::_switchable_test;
    34 GrowableArray<int> *MethodComparator::_fwd_jmps;
    36 bool MethodComparator::methods_EMCP(methodOop old_method, methodOop new_method) {
    37   if (old_method->code_size() != new_method->code_size())
    38     return false;
    39   if (check_stack_and_locals_size(old_method, new_method) != 0) {
    40     // RC_TRACE macro has an embedded ResourceMark
    41     RC_TRACE(0x00800000, ("Methods %s non-comparable with diagnosis %d",
    42       old_method->name()->as_C_string(),
    43       check_stack_and_locals_size(old_method, new_method)));
    44     return false;
    45   }
    47   _old_cp = old_method->constants();
    48   _new_cp = new_method->constants();
    49   BytecodeStream s_old(old_method);
    50   BytecodeStream s_new(new_method);
    51   _s_old = &s_old;
    52   _s_new = &s_new;
    53   _switchable_test = false;
    54   Bytecodes::Code c_old, c_new;
    56   while ((c_old = s_old.next()) >= 0) {
    57     if ((c_new = s_new.next()) < 0 || c_old != c_new)
    58       return false;
    60     if (! args_same(c_old, c_new))
    61       return false;
    62   }
    63   return true;
    64 }
    67 bool MethodComparator::methods_switchable(methodOop old_method, methodOop new_method,
    68                                           BciMap &bci_map) {
    69   if (old_method->code_size() > new_method->code_size())
    70     // Something has definitely been deleted in the new method, compared to the old one.
    71     return false;
    73   if (! check_stack_and_locals_size(old_method, new_method))
    74     return false;
    76   _old_cp = old_method->constants();
    77   _new_cp = new_method->constants();
    78   BytecodeStream s_old(old_method);
    79   BytecodeStream s_new(new_method);
    80   _s_old = &s_old;
    81   _s_new = &s_new;
    82   _bci_map = &bci_map;
    83   _switchable_test = true;
    84   GrowableArray<int> fwd_jmps(16);
    85   _fwd_jmps = &fwd_jmps;
    86   Bytecodes::Code c_old, c_new;
    88   while ((c_old = s_old.next()) >= 0) {
    89     if ((c_new = s_new.next()) < 0)
    90       return false;
    91     if (! (c_old == c_new && args_same(c_old, c_new))) {
    92       int old_bci = s_old.bci();
    93       int new_st_bci = s_new.bci();
    94       bool found_match = false;
    95       do {
    96         c_new = s_new.next();
    97         if (c_new == c_old && args_same(c_old, c_new)) {
    98           found_match = true;
    99           break;
   100         }
   101       } while (c_new >= 0);
   102       if (! found_match)
   103         return false;
   104       int new_end_bci = s_new.bci();
   105       bci_map.store_fragment_location(old_bci, new_st_bci, new_end_bci);
   106     }
   107   }
   109   // Now we can test all forward jumps
   110   for (int i = 0; i < fwd_jmps.length() / 2; i++) {
   111     if (! bci_map.old_and_new_locations_same(fwd_jmps.at(i*2), fwd_jmps.at(i*2+1))) {
   112       RC_TRACE(0x00800000,
   113         ("Fwd jump miss: old dest = %d, calc new dest = %d, act new dest = %d",
   114         fwd_jmps.at(i*2), bci_map.new_bci_for_old(fwd_jmps.at(i*2)),
   115         fwd_jmps.at(i*2+1)));
   116       return false;
   117     }
   118   }
   120   return true;
   121 }
   124 bool MethodComparator::args_same(Bytecodes::Code c_old, Bytecodes::Code c_new) {
   125   // BytecodeStream returns the correct standard Java bytecodes for various "fast"
   126   // bytecode versions, so we don't have to bother about them here..
   127   switch (c_old) {
   128   case Bytecodes::_new            : // fall through
   129   case Bytecodes::_anewarray      : // fall through
   130   case Bytecodes::_multianewarray : // fall through
   131   case Bytecodes::_checkcast      : // fall through
   132   case Bytecodes::_instanceof     : {
   133     u2 cpi_old = _s_old->get_index_u2();
   134     u2 cpi_new = _s_new->get_index_u2();
   135     if ((_old_cp->klass_at_noresolve(cpi_old) != _new_cp->klass_at_noresolve(cpi_new)))
   136         return false;
   137     if (c_old == Bytecodes::_multianewarray &&
   138         *(jbyte*)(_s_old->bcp() + 3) != *(jbyte*)(_s_new->bcp() + 3))
   139       return false;
   140     break;
   141   }
   143   case Bytecodes::_getstatic       : // fall through
   144   case Bytecodes::_putstatic       : // fall through
   145   case Bytecodes::_getfield        : // fall through
   146   case Bytecodes::_putfield        : // fall through
   147   case Bytecodes::_invokevirtual   : // fall through
   148   case Bytecodes::_invokespecial   : // fall through
   149   case Bytecodes::_invokestatic    : // fall through
   150   case Bytecodes::_invokedynamic   : // fall through
   151   case Bytecodes::_invokeinterface : {
   152     int cpci_old = _s_old->has_index_u4() ? _s_old->get_index_u4() : _s_old->get_index_u2_cpcache();
   153     int cpci_new = _s_new->has_index_u4() ? _s_new->get_index_u4() : _s_new->get_index_u2_cpcache();
   154     // Check if the names of classes, field/method names and signatures at these indexes
   155     // are the same. Indices which are really into constantpool cache (rather than constant
   156     // pool itself) are accepted by the constantpool query routines below.
   157     if ((_old_cp->klass_ref_at_noresolve(cpci_old) != _new_cp->klass_ref_at_noresolve(cpci_new)) ||
   158         (_old_cp->name_ref_at(cpci_old) != _new_cp->name_ref_at(cpci_new)) ||
   159         (_old_cp->signature_ref_at(cpci_old) != _new_cp->signature_ref_at(cpci_new)))
   160       return false;
   161     break;
   162   }
   164   case Bytecodes::_ldc   : // fall through
   165   case Bytecodes::_ldc_w : {
   166     Bytecode_loadconstant* ldc_old = Bytecode_loadconstant_at(_s_old->method(), _s_old->bci());
   167     Bytecode_loadconstant* ldc_new = Bytecode_loadconstant_at(_s_new->method(), _s_new->bci());
   168     int cpi_old = ldc_old->pool_index();
   169     int cpi_new = ldc_new->pool_index();
   170     constantTag tag_old = _old_cp->tag_at(cpi_old);
   171     constantTag tag_new = _new_cp->tag_at(cpi_new);
   172     if (tag_old.is_int() || tag_old.is_float()) {
   173       if (tag_old.value() != tag_new.value())
   174         return false;
   175       if (tag_old.is_int()) {
   176         if (_old_cp->int_at(cpi_old) != _new_cp->int_at(cpi_new))
   177           return false;
   178       } else {
   179         // Use jint_cast to compare the bits rather than numerical values.
   180         // This makes a difference for NaN constants.
   181         if (jint_cast(_old_cp->float_at(cpi_old)) != jint_cast(_new_cp->float_at(cpi_new)))
   182           return false;
   183       }
   184     } else if (tag_old.is_string() || tag_old.is_unresolved_string()) {
   185       if (! (tag_new.is_unresolved_string() || tag_new.is_string()))
   186         return false;
   187       if (strcmp(_old_cp->string_at_noresolve(cpi_old),
   188                  _new_cp->string_at_noresolve(cpi_new)) != 0)
   189         return false;
   190     } else if (tag_old.is_klass() || tag_old.is_unresolved_klass()) {
   191       // tag_old should be klass - 4881222
   192       if (! (tag_new.is_unresolved_klass() || tag_new.is_klass()))
   193         return false;
   194       if (_old_cp->klass_at_noresolve(cpi_old) !=
   195           _new_cp->klass_at_noresolve(cpi_new))
   196         return false;
   197     } else if (tag_old.is_method_type() && tag_new.is_method_type()) {
   198       int mti_old = _old_cp->method_type_index_at(cpi_old);
   199       int mti_new = _new_cp->method_type_index_at(cpi_new);
   200       if ((_old_cp->symbol_at(mti_old) != _new_cp->symbol_at(mti_new)))
   201         return false;
   202     } else if (tag_old.is_method_handle() && tag_new.is_method_handle()) {
   203       if (_old_cp->method_handle_ref_kind_at(cpi_old) !=
   204           _new_cp->method_handle_ref_kind_at(cpi_new))
   205         return false;
   206       int mhi_old = _old_cp->method_handle_index_at(cpi_old);
   207       int mhi_new = _new_cp->method_handle_index_at(cpi_new);
   208       if ((_old_cp->uncached_klass_ref_at_noresolve(mhi_old) != _new_cp->uncached_klass_ref_at_noresolve(mhi_new)) ||
   209           (_old_cp->uncached_name_ref_at(mhi_old) != _new_cp->uncached_name_ref_at(mhi_new)) ||
   210           (_old_cp->uncached_signature_ref_at(mhi_old) != _new_cp->uncached_signature_ref_at(mhi_new)))
   211         return false;
   212     } else {
   213       return false;  // unknown tag
   214     }
   215     break;
   216   }
   218   case Bytecodes::_ldc2_w : {
   219     u2 cpi_old = _s_old->get_index_u2();
   220     u2 cpi_new = _s_new->get_index_u2();
   221     constantTag tag_old = _old_cp->tag_at(cpi_old);
   222     constantTag tag_new = _new_cp->tag_at(cpi_new);
   223     if (tag_old.value() != tag_new.value())
   224       return false;
   225     if (tag_old.is_long()) {
   226       if (_old_cp->long_at(cpi_old) != _new_cp->long_at(cpi_new))
   227         return false;
   228     } else {
   229       // Use jlong_cast to compare the bits rather than numerical values.
   230       // This makes a difference for NaN constants.
   231       if (jlong_cast(_old_cp->double_at(cpi_old)) != jlong_cast(_new_cp->double_at(cpi_new)))
   232         return false;
   233     }
   234     break;
   235   }
   237   case Bytecodes::_bipush :
   238     if (_s_old->bcp()[1] != _s_new->bcp()[1])
   239       return false;
   240     break;
   242   case Bytecodes::_sipush    :
   243     if (_s_old->get_index_u2() != _s_new->get_index_u2())
   244       return false;
   245     break;
   247   case Bytecodes::_aload  : // fall through
   248   case Bytecodes::_astore : // fall through
   249   case Bytecodes::_dload  : // fall through
   250   case Bytecodes::_dstore : // fall through
   251   case Bytecodes::_fload  : // fall through
   252   case Bytecodes::_fstore : // fall through
   253   case Bytecodes::_iload  : // fall through
   254   case Bytecodes::_istore : // fall through
   255   case Bytecodes::_lload  : // fall through
   256   case Bytecodes::_lstore : // fall through
   257   case Bytecodes::_ret    :
   258     if (_s_old->is_wide() != _s_new->is_wide())
   259       return false;
   260     if (_s_old->get_index() != _s_new->get_index())
   261       return false;
   262     break;
   264   case Bytecodes::_goto      : // fall through
   265   case Bytecodes::_if_acmpeq : // fall through
   266   case Bytecodes::_if_acmpne : // fall through
   267   case Bytecodes::_if_icmpeq : // fall through
   268   case Bytecodes::_if_icmpne : // fall through
   269   case Bytecodes::_if_icmplt : // fall through
   270   case Bytecodes::_if_icmpge : // fall through
   271   case Bytecodes::_if_icmpgt : // fall through
   272   case Bytecodes::_if_icmple : // fall through
   273   case Bytecodes::_ifeq      : // fall through
   274   case Bytecodes::_ifne      : // fall through
   275   case Bytecodes::_iflt      : // fall through
   276   case Bytecodes::_ifge      : // fall through
   277   case Bytecodes::_ifgt      : // fall through
   278   case Bytecodes::_ifle      : // fall through
   279   case Bytecodes::_ifnonnull : // fall through
   280   case Bytecodes::_ifnull    : // fall through
   281   case Bytecodes::_jsr       : {
   282     int old_ofs = _s_old->bytecode()->get_offset_s2(c_old);
   283     int new_ofs = _s_new->bytecode()->get_offset_s2(c_new);
   284     if (_switchable_test) {
   285       int old_dest = _s_old->bci() + old_ofs;
   286       int new_dest = _s_new->bci() + new_ofs;
   287       if (old_ofs < 0 && new_ofs < 0) {
   288         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
   289           return false;
   290       } else if (old_ofs > 0 && new_ofs > 0) {
   291         _fwd_jmps->append(old_dest);
   292         _fwd_jmps->append(new_dest);
   293       } else {
   294         return false;
   295       }
   296     } else {
   297       if (old_ofs != new_ofs)
   298         return false;
   299     }
   300     break;
   301   }
   303   case Bytecodes::_iinc :
   304     if (_s_old->is_wide() != _s_new->is_wide())
   305       return false;
   306     if (! _s_old->is_wide()) {
   307       // We could use get_index_u1 and get_constant_u1, but it's simpler to grab both bytes at once:
   308       if (Bytes::get_Java_u2(_s_old->bcp() + 1) != Bytes::get_Java_u2(_s_new->bcp() + 1))
   309         return false;
   310     } else {
   311       // We could use get_index_u2 and get_constant_u2, but it's simpler to grab all four bytes at once:
   312       if (Bytes::get_Java_u4(_s_old->bcp() + 1) != Bytes::get_Java_u4(_s_new->bcp() + 1))
   313         return false;
   314     }
   315     break;
   317   case Bytecodes::_goto_w : // fall through
   318   case Bytecodes::_jsr_w  : {
   319     int old_ofs = _s_old->bytecode()->get_offset_s4(c_old);
   320     int new_ofs = _s_new->bytecode()->get_offset_s4(c_new);
   321     if (_switchable_test) {
   322       int old_dest = _s_old->bci() + old_ofs;
   323       int new_dest = _s_new->bci() + new_ofs;
   324       if (old_ofs < 0 && new_ofs < 0) {
   325         if (! _bci_map->old_and_new_locations_same(old_dest, new_dest))
   326           return false;
   327       } else if (old_ofs > 0 && new_ofs > 0) {
   328         _fwd_jmps->append(old_dest);
   329         _fwd_jmps->append(new_dest);
   330       } else {
   331         return false;
   332       }
   333     } else {
   334       if (old_ofs != new_ofs)
   335         return false;
   336     }
   337     break;
   338   }
   340   case Bytecodes::_lookupswitch : // fall through
   341   case Bytecodes::_tableswitch  : {
   342     if (_switchable_test) {
   343       address aligned_bcp_old = (address) round_to((intptr_t)_s_old->bcp() + 1, jintSize);
   344       address aligned_bcp_new = (address) round_to((intptr_t)_s_new->bcp() + 1, jintSize);
   345       int default_old = (int) Bytes::get_Java_u4(aligned_bcp_old);
   346       int default_new = (int) Bytes::get_Java_u4(aligned_bcp_new);
   347       _fwd_jmps->append(_s_old->bci() + default_old);
   348       _fwd_jmps->append(_s_new->bci() + default_new);
   349       if (c_old == Bytecodes::_lookupswitch) {
   350         int npairs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
   351         int npairs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
   352         if (npairs_old != npairs_new)
   353           return false;
   354         for (int i = 0; i < npairs_old; i++) {
   355           int match_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i)*jintSize);
   356           int match_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i)*jintSize);
   357           if (match_old != match_new)
   358             return false;
   359           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (2+2*i+1)*jintSize);
   360           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (2+2*i+1)*jintSize);
   361           _fwd_jmps->append(_s_old->bci() + ofs_old);
   362           _fwd_jmps->append(_s_new->bci() + ofs_new);
   363         }
   364       } else if (c_old == Bytecodes::_tableswitch) {
   365         int lo_old = (int) Bytes::get_Java_u4(aligned_bcp_old + jintSize);
   366         int lo_new = (int) Bytes::get_Java_u4(aligned_bcp_new + jintSize);
   367         if (lo_old != lo_new)
   368           return false;
   369         int hi_old = (int) Bytes::get_Java_u4(aligned_bcp_old + 2*jintSize);
   370         int hi_new = (int) Bytes::get_Java_u4(aligned_bcp_new + 2*jintSize);
   371         if (hi_old != hi_new)
   372           return false;
   373         for (int i = 0; i < hi_old - lo_old + 1; i++) {
   374           int ofs_old = (int) Bytes::get_Java_u4(aligned_bcp_old + (3+i)*jintSize);
   375           int ofs_new = (int) Bytes::get_Java_u4(aligned_bcp_new + (3+i)*jintSize);
   376           _fwd_jmps->append(_s_old->bci() + ofs_old);
   377           _fwd_jmps->append(_s_new->bci() + ofs_new);
   378         }
   379       }
   380     } else { // !_switchable_test, can use fast rough compare
   381       int len_old = _s_old->instruction_size();
   382       int len_new = _s_new->instruction_size();
   383       if (len_old != len_new)
   384         return false;
   385       if (memcmp(_s_old->bcp(), _s_new->bcp(), len_old) != 0)
   386         return false;
   387     }
   388     break;
   389   }
   390   }
   392   return true;
   393 }
   396 int MethodComparator::check_stack_and_locals_size(methodOop old_method, methodOop new_method) {
   397   if (old_method->max_stack() != new_method->max_stack()) {
   398     return 1;
   399   } else if (old_method->max_locals() != new_method->max_locals()) {
   400     return 2;
   401   } else if (old_method->size_of_parameters() != new_method->size_of_parameters()) {
   402     return 3;
   403   } else return 0;
   404 }

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