src/share/vm/ci/ciInstanceKlass.cpp

Thu, 27 Jan 2011 16:11:27 -0800

author
coleenp
date
Thu, 27 Jan 2011 16:11:27 -0800
changeset 2497
3582bf76420e
parent 2314
f95d63e2154a
child 2551
4f26f535a225
permissions
-rw-r--r--

6990754: Use native memory and reference counting to implement SymbolTable
Summary: move symbols from permgen into C heap and reference count them
Reviewed-by: never, acorn, jmasa, stefank

     1 /*
     2  * Copyright (c) 1999, 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 "precompiled.hpp"
    26 #include "ci/ciField.hpp"
    27 #include "ci/ciInstance.hpp"
    28 #include "ci/ciInstanceKlass.hpp"
    29 #include "ci/ciUtilities.hpp"
    30 #include "classfile/systemDictionary.hpp"
    31 #include "memory/allocation.hpp"
    32 #include "memory/allocation.inline.hpp"
    33 #include "oops/oop.inline.hpp"
    34 #include "runtime/fieldDescriptor.hpp"
    36 // ciInstanceKlass
    37 //
    38 // This class represents a klassOop in the HotSpot virtual machine
    39 // whose Klass part in an instanceKlass.
    41 // ------------------------------------------------------------------
    42 // ciInstanceKlass::ciInstanceKlass
    43 //
    44 // Loaded instance klass.
    45 ciInstanceKlass::ciInstanceKlass(KlassHandle h_k) :
    46   ciKlass(h_k), _non_static_fields(NULL)
    47 {
    48   assert(get_Klass()->oop_is_instance(), "wrong type");
    49   instanceKlass* ik = get_instanceKlass();
    51   AccessFlags access_flags = ik->access_flags();
    52   _flags = ciFlags(access_flags);
    53   _has_finalizer = access_flags.has_finalizer();
    54   _has_subklass = ik->subklass() != NULL;
    55   _init_state = (instanceKlass::ClassState)ik->get_init_state();
    56   _nonstatic_field_size = ik->nonstatic_field_size();
    57   _has_nonstatic_fields = ik->has_nonstatic_fields();
    58   _nonstatic_fields = NULL; // initialized lazily by compute_nonstatic_fields:
    60   _nof_implementors = ik->nof_implementors();
    61   for (int i = 0; i < implementors_limit; i++) {
    62     _implementors[i] = NULL;  // we will fill these lazily
    63   }
    65   Thread *thread = Thread::current();
    66   if (ciObjectFactory::is_initialized()) {
    67     _loader = JNIHandles::make_local(thread, ik->class_loader());
    68     _protection_domain = JNIHandles::make_local(thread,
    69                                                 ik->protection_domain());
    70     _is_shared = false;
    71   } else {
    72     Handle h_loader(thread, ik->class_loader());
    73     Handle h_protection_domain(thread, ik->protection_domain());
    74     _loader = JNIHandles::make_global(h_loader);
    75     _protection_domain = JNIHandles::make_global(h_protection_domain);
    76     _is_shared = true;
    77   }
    79   // Lazy fields get filled in only upon request.
    80   _super  = NULL;
    81   _java_mirror = NULL;
    83   if (is_shared()) {
    84     if (h_k() != SystemDictionary::Object_klass()) {
    85       super();
    86     }
    87     java_mirror();
    88     //compute_nonstatic_fields();  // done outside of constructor
    89   }
    91   _field_cache = NULL;
    92 }
    94 // Version for unloaded classes:
    95 ciInstanceKlass::ciInstanceKlass(ciSymbol* name,
    96                                  jobject loader, jobject protection_domain)
    97   : ciKlass(name, ciInstanceKlassKlass::make())
    98 {
    99   assert(name->byte_at(0) != '[', "not an instance klass");
   100   _init_state = (instanceKlass::ClassState)0;
   101   _nonstatic_field_size = -1;
   102   _has_nonstatic_fields = false;
   103   _nonstatic_fields = NULL;
   104   _nof_implementors = -1;
   105   _loader = loader;
   106   _protection_domain = protection_domain;
   107   _is_shared = false;
   108   _super = NULL;
   109   _java_mirror = NULL;
   110   _field_cache = NULL;
   111 }
   115 // ------------------------------------------------------------------
   116 // ciInstanceKlass::compute_shared_is_initialized
   117 void ciInstanceKlass::compute_shared_init_state() {
   118   GUARDED_VM_ENTRY(
   119     instanceKlass* ik = get_instanceKlass();
   120     _init_state = (instanceKlass::ClassState)ik->get_init_state();
   121   )
   122 }
   124 // ------------------------------------------------------------------
   125 // ciInstanceKlass::compute_shared_has_subklass
   126 bool ciInstanceKlass::compute_shared_has_subklass() {
   127   GUARDED_VM_ENTRY(
   128     instanceKlass* ik = get_instanceKlass();
   129     _has_subklass = ik->subklass() != NULL;
   130     return _has_subklass;
   131   )
   132 }
   134 // ------------------------------------------------------------------
   135 // ciInstanceKlass::compute_shared_nof_implementors
   136 int ciInstanceKlass::compute_shared_nof_implementors() {
   137   // We requery this property, since it is a very old ciObject.
   138   GUARDED_VM_ENTRY(
   139     instanceKlass* ik = get_instanceKlass();
   140     _nof_implementors = ik->nof_implementors();
   141     return _nof_implementors;
   142   )
   143 }
   145 // ------------------------------------------------------------------
   146 // ciInstanceKlass::loader
   147 oop ciInstanceKlass::loader() {
   148   ASSERT_IN_VM;
   149   return JNIHandles::resolve(_loader);
   150 }
   152 // ------------------------------------------------------------------
   153 // ciInstanceKlass::loader_handle
   154 jobject ciInstanceKlass::loader_handle() {
   155   return _loader;
   156 }
   158 // ------------------------------------------------------------------
   159 // ciInstanceKlass::protection_domain
   160 oop ciInstanceKlass::protection_domain() {
   161   ASSERT_IN_VM;
   162   return JNIHandles::resolve(_protection_domain);
   163 }
   165 // ------------------------------------------------------------------
   166 // ciInstanceKlass::protection_domain_handle
   167 jobject ciInstanceKlass::protection_domain_handle() {
   168   return _protection_domain;
   169 }
   171 // ------------------------------------------------------------------
   172 // ciInstanceKlass::field_cache
   173 //
   174 // Get the field cache associated with this klass.
   175 ciConstantPoolCache* ciInstanceKlass::field_cache() {
   176   if (is_shared()) {
   177     return NULL;
   178   }
   179   if (_field_cache == NULL) {
   180     assert(!is_java_lang_Object(), "Object has no fields");
   181     Arena* arena = CURRENT_ENV->arena();
   182     _field_cache = new (arena) ciConstantPoolCache(arena, 5);
   183   }
   184   return _field_cache;
   185 }
   187 // ------------------------------------------------------------------
   188 // ciInstanceKlass::get_canonical_holder
   189 //
   190 ciInstanceKlass* ciInstanceKlass::get_canonical_holder(int offset) {
   191   #ifdef ASSERT
   192   if (!(offset >= 0 && offset < layout_helper())) {
   193     tty->print("*** get_canonical_holder(%d) on ", offset);
   194     this->print();
   195     tty->print_cr(" ***");
   196   };
   197   assert(offset >= 0 && offset < layout_helper(), "offset must be tame");
   198   #endif
   200   if (offset < instanceOopDesc::base_offset_in_bytes()) {
   201     // All header offsets belong properly to java/lang/Object.
   202     return CURRENT_ENV->Object_klass();
   203   }
   205   ciInstanceKlass* self = this;
   206   for (;;) {
   207     assert(self->is_loaded(), "must be loaded to have size");
   208     ciInstanceKlass* super = self->super();
   209     if (super == NULL || super->nof_nonstatic_fields() == 0 ||
   210         !super->contains_field_offset(offset)) {
   211       return self;
   212     } else {
   213       self = super;  // return super->get_canonical_holder(offset)
   214     }
   215   }
   216 }
   218 // ------------------------------------------------------------------
   219 // ciInstanceKlass::is_java_lang_Object
   220 //
   221 // Is this klass java.lang.Object?
   222 bool ciInstanceKlass::is_java_lang_Object() {
   223   return equals(CURRENT_ENV->Object_klass());
   224 }
   226 // ------------------------------------------------------------------
   227 // ciInstanceKlass::uses_default_loader
   228 bool ciInstanceKlass::uses_default_loader() {
   229   // Note:  We do not need to resolve the handle or enter the VM
   230   // in order to test null-ness.
   231   return _loader == NULL;
   232 }
   234 // ------------------------------------------------------------------
   235 // ciInstanceKlass::is_in_package
   236 //
   237 // Is this klass in the given package?
   238 bool ciInstanceKlass::is_in_package(const char* packagename, int len) {
   239   // To avoid class loader mischief, this test always rejects application classes.
   240   if (!uses_default_loader())
   241     return false;
   242   GUARDED_VM_ENTRY(
   243     return is_in_package_impl(packagename, len);
   244   )
   245 }
   247 bool ciInstanceKlass::is_in_package_impl(const char* packagename, int len) {
   248   ASSERT_IN_VM;
   250   // If packagename contains trailing '/' exclude it from the
   251   // prefix-test since we test for it explicitly.
   252   if (packagename[len - 1] == '/')
   253     len--;
   255   if (!name()->starts_with(packagename, len))
   256     return false;
   258   // Test if the class name is something like "java/lang".
   259   if ((len + 1) > name()->utf8_length())
   260     return false;
   262   // Test for trailing '/'
   263   if ((char) name()->byte_at(len) != '/')
   264     return false;
   266   // Make sure it's not actually in a subpackage:
   267   if (name()->index_of_at(len+1, "/", 1) >= 0)
   268     return false;
   270   return true;
   271 }
   273 // ------------------------------------------------------------------
   274 // ciInstanceKlass::print_impl
   275 //
   276 // Implementation of the print method.
   277 void ciInstanceKlass::print_impl(outputStream* st) {
   278   ciKlass::print_impl(st);
   279   GUARDED_VM_ENTRY(st->print(" loader=0x%x", (address)loader());)
   280   if (is_loaded()) {
   281     st->print(" loaded=true initialized=%s finalized=%s subklass=%s size=%d flags=",
   282               bool_to_str(is_initialized()),
   283               bool_to_str(has_finalizer()),
   284               bool_to_str(has_subklass()),
   285               layout_helper());
   287     _flags.print_klass_flags();
   289     if (_super) {
   290       st->print(" super=");
   291       _super->print_name();
   292     }
   293     if (_java_mirror) {
   294       st->print(" mirror=PRESENT");
   295     }
   296   } else {
   297     st->print(" loaded=false");
   298   }
   299 }
   301 // ------------------------------------------------------------------
   302 // ciInstanceKlass::super
   303 //
   304 // Get the superklass of this klass.
   305 ciInstanceKlass* ciInstanceKlass::super() {
   306   assert(is_loaded(), "must be loaded");
   307   if (_super == NULL && !is_java_lang_Object()) {
   308     GUARDED_VM_ENTRY(
   309       klassOop super_klass = get_instanceKlass()->super();
   310       _super = CURRENT_ENV->get_object(super_klass)->as_instance_klass();
   311     )
   312   }
   313   return _super;
   314 }
   316 // ------------------------------------------------------------------
   317 // ciInstanceKlass::java_mirror
   318 //
   319 // Get the instance of java.lang.Class corresponding to this klass.
   320 // Cache it on this->_java_mirror.
   321 ciInstance* ciInstanceKlass::java_mirror() {
   322   if (_java_mirror == NULL) {
   323     _java_mirror = ciKlass::java_mirror();
   324   }
   325   return _java_mirror;
   326 }
   328 // ------------------------------------------------------------------
   329 // ciInstanceKlass::unique_concrete_subklass
   330 ciInstanceKlass* ciInstanceKlass::unique_concrete_subklass() {
   331   if (!is_loaded())     return NULL; // No change if class is not loaded
   332   if (!is_abstract())   return NULL; // Only applies to abstract classes.
   333   if (!has_subklass())  return NULL; // Must have at least one subklass.
   334   VM_ENTRY_MARK;
   335   instanceKlass* ik = get_instanceKlass();
   336   Klass* up = ik->up_cast_abstract();
   337   assert(up->oop_is_instance(), "must be instanceKlass");
   338   if (ik == up) {
   339     return NULL;
   340   }
   341   return CURRENT_THREAD_ENV->get_object(up->as_klassOop())->as_instance_klass();
   342 }
   344 // ------------------------------------------------------------------
   345 // ciInstanceKlass::has_finalizable_subclass
   346 bool ciInstanceKlass::has_finalizable_subclass() {
   347   if (!is_loaded())     return true;
   348   VM_ENTRY_MARK;
   349   return Dependencies::find_finalizable_subclass(get_instanceKlass()) != NULL;
   350 }
   352 // ------------------------------------------------------------------
   353 // ciInstanceKlass::get_field_by_offset
   354 ciField* ciInstanceKlass::get_field_by_offset(int field_offset, bool is_static) {
   355   if (!is_static) {
   356     for (int i = 0, len = nof_nonstatic_fields(); i < len; i++) {
   357       ciField* field = _nonstatic_fields->at(i);
   358       int  field_off = field->offset_in_bytes();
   359       if (field_off == field_offset)
   360         return field;
   361       if (field_off > field_offset)
   362         break;
   363       // could do binary search or check bins, but probably not worth it
   364     }
   365     return NULL;
   366   }
   367   VM_ENTRY_MARK;
   368   instanceKlass* k = get_instanceKlass();
   369   fieldDescriptor fd;
   370   if (!k->find_field_from_offset(field_offset, is_static, &fd)) {
   371     return NULL;
   372   }
   373   ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
   374   return field;
   375 }
   377 // ------------------------------------------------------------------
   378 // ciInstanceKlass::get_field_by_name
   379 ciField* ciInstanceKlass::get_field_by_name(ciSymbol* name, ciSymbol* signature, bool is_static) {
   380   VM_ENTRY_MARK;
   381   instanceKlass* k = get_instanceKlass();
   382   fieldDescriptor fd;
   383   klassOop def = k->find_field(name->get_symbol(), signature->get_symbol(), is_static, &fd);
   384   if (def == NULL) {
   385     return NULL;
   386   }
   387   ciField* field = new (CURRENT_THREAD_ENV->arena()) ciField(&fd);
   388   return field;
   389 }
   391 // ------------------------------------------------------------------
   392 // ciInstanceKlass::non_static_fields.
   394 class NonStaticFieldFiller: public FieldClosure {
   395   GrowableArray<ciField*>* _arr;
   396   ciEnv* _curEnv;
   397 public:
   398   NonStaticFieldFiller(ciEnv* curEnv, GrowableArray<ciField*>* arr) :
   399     _curEnv(curEnv), _arr(arr)
   400   {}
   401   void do_field(fieldDescriptor* fd) {
   402     ciField* field = new (_curEnv->arena()) ciField(fd);
   403     _arr->append(field);
   404   }
   405 };
   407 GrowableArray<ciField*>* ciInstanceKlass::non_static_fields() {
   408   if (_non_static_fields == NULL) {
   409     VM_ENTRY_MARK;
   410     ciEnv* curEnv = ciEnv::current();
   411     instanceKlass* ik = get_instanceKlass();
   412     int max_n_fields = ik->fields()->length()/instanceKlass::next_offset;
   414     Arena* arena = curEnv->arena();
   415     _non_static_fields =
   416       new (arena) GrowableArray<ciField*>(arena, max_n_fields, 0, NULL);
   417     NonStaticFieldFiller filler(curEnv, _non_static_fields);
   418     ik->do_nonstatic_fields(&filler);
   419   }
   420   return _non_static_fields;
   421 }
   423 static int sort_field_by_offset(ciField** a, ciField** b) {
   424   return (*a)->offset_in_bytes() - (*b)->offset_in_bytes();
   425   // (no worries about 32-bit overflow...)
   426 }
   428 // ------------------------------------------------------------------
   429 // ciInstanceKlass::compute_nonstatic_fields
   430 int ciInstanceKlass::compute_nonstatic_fields() {
   431   assert(is_loaded(), "must be loaded");
   433   if (_nonstatic_fields != NULL)
   434     return _nonstatic_fields->length();
   436   if (!has_nonstatic_fields()) {
   437     Arena* arena = CURRENT_ENV->arena();
   438     _nonstatic_fields = new (arena) GrowableArray<ciField*>(arena, 0, 0, NULL);
   439     return 0;
   440   }
   441   assert(!is_java_lang_Object(), "bootstrap OK");
   443   // Size in bytes of my fields, including inherited fields.
   444   int fsize = nonstatic_field_size() * heapOopSize;
   446   ciInstanceKlass* super = this->super();
   447   GrowableArray<ciField*>* super_fields = NULL;
   448   if (super != NULL && super->has_nonstatic_fields()) {
   449     int super_fsize  = super->nonstatic_field_size() * heapOopSize;
   450     int super_flen   = super->nof_nonstatic_fields();
   451     super_fields = super->_nonstatic_fields;
   452     assert(super_flen == 0 || super_fields != NULL, "first get nof_fields");
   453     // See if I am no larger than my super; if so, I can use his fields.
   454     if (fsize == super_fsize) {
   455       _nonstatic_fields = super_fields;
   456       return super_fields->length();
   457     }
   458   }
   460   GrowableArray<ciField*>* fields = NULL;
   461   GUARDED_VM_ENTRY({
   462       fields = compute_nonstatic_fields_impl(super_fields);
   463     });
   465   if (fields == NULL) {
   466     // This can happen if this class (java.lang.Class) has invisible fields.
   467     _nonstatic_fields = super_fields;
   468     return super_fields->length();
   469   }
   471   int flen = fields->length();
   473   // Now sort them by offset, ascending.
   474   // (In principle, they could mix with superclass fields.)
   475   fields->sort(sort_field_by_offset);
   476 #ifdef ASSERT
   477   int last_offset = instanceOopDesc::base_offset_in_bytes();
   478   for (int i = 0; i < fields->length(); i++) {
   479     ciField* field = fields->at(i);
   480     int offset = field->offset_in_bytes();
   481     int size   = (field->_type == NULL) ? heapOopSize : field->size_in_bytes();
   482     assert(last_offset <= offset, err_msg("no field overlap: %d <= %d", last_offset, offset));
   483     if (last_offset > (int)sizeof(oopDesc))
   484       assert((offset - last_offset) < BytesPerLong, "no big holes");
   485     // Note:  Two consecutive T_BYTE fields will be separated by wordSize-1
   486     // padding bytes if one of them is declared by a superclass.
   487     // This is a minor inefficiency classFileParser.cpp.
   488     last_offset = offset + size;
   489   }
   490   assert(last_offset <= (int)instanceOopDesc::base_offset_in_bytes() + fsize, "no overflow");
   491 #endif
   493   _nonstatic_fields = fields;
   494   return flen;
   495 }
   497 GrowableArray<ciField*>*
   498 ciInstanceKlass::compute_nonstatic_fields_impl(GrowableArray<ciField*>*
   499                                                super_fields) {
   500   ASSERT_IN_VM;
   501   Arena* arena = CURRENT_ENV->arena();
   502   int flen = 0;
   503   GrowableArray<ciField*>* fields = NULL;
   504   instanceKlass* k = get_instanceKlass();
   505   typeArrayOop fields_array = k->fields();
   506   for (int pass = 0; pass <= 1; pass++) {
   507     for (int i = 0, alen = fields_array->length(); i < alen; i += instanceKlass::next_offset) {
   508       fieldDescriptor fd;
   509       fd.initialize(k->as_klassOop(), i);
   510       if (fd.is_static())  continue;
   511       if (pass == 0) {
   512         flen += 1;
   513       } else {
   514         ciField* field = new (arena) ciField(&fd);
   515         fields->append(field);
   516       }
   517     }
   519     // Between passes, allocate the array:
   520     if (pass == 0) {
   521       if (flen == 0) {
   522         return NULL;  // return nothing if none are locally declared
   523       }
   524       if (super_fields != NULL) {
   525         flen += super_fields->length();
   526       }
   527       fields = new (arena) GrowableArray<ciField*>(arena, flen, 0, NULL);
   528       if (super_fields != NULL) {
   529         fields->appendAll(super_fields);
   530       }
   531     }
   532   }
   533   assert(fields->length() == flen, "sanity");
   534   return fields;
   535 }
   537 // ------------------------------------------------------------------
   538 // ciInstanceKlass::find_method
   539 //
   540 // Find a method in this klass.
   541 ciMethod* ciInstanceKlass::find_method(ciSymbol* name, ciSymbol* signature) {
   542   VM_ENTRY_MARK;
   543   instanceKlass* k = get_instanceKlass();
   544   Symbol* name_sym = name->get_symbol();
   545   Symbol* sig_sym= signature->get_symbol();
   547   methodOop m = k->find_method(name_sym, sig_sym);
   548   if (m == NULL)  return NULL;
   550   return CURRENT_THREAD_ENV->get_object(m)->as_method();
   551 }
   553 // ------------------------------------------------------------------
   554 // ciInstanceKlass::is_leaf_type
   555 bool ciInstanceKlass::is_leaf_type() {
   556   assert(is_loaded(), "must be loaded");
   557   if (is_shared()) {
   558     return is_final();  // approximately correct
   559   } else {
   560     return !_has_subklass && (_nof_implementors == 0);
   561   }
   562 }
   564 // ------------------------------------------------------------------
   565 // ciInstanceKlass::implementor
   566 //
   567 // Report an implementor of this interface.
   568 // Returns NULL if exact information is not available.
   569 // Note that there are various races here, since my copy
   570 // of _nof_implementors might be out of date with respect
   571 // to results returned by instanceKlass::implementor.
   572 // This is OK, since any dependencies we decide to assert
   573 // will be checked later under the Compile_lock.
   574 ciInstanceKlass* ciInstanceKlass::implementor(int n) {
   575   if (n >= implementors_limit) {
   576     return NULL;
   577   }
   578   ciInstanceKlass* impl = _implementors[n];
   579   if (impl == NULL) {
   580     if (_nof_implementors > implementors_limit) {
   581       return NULL;
   582     }
   583     // Go into the VM to fetch the implementor.
   584     {
   585       VM_ENTRY_MARK;
   586       klassOop k = get_instanceKlass()->implementor(n);
   587       if (k != NULL) {
   588         impl = CURRENT_THREAD_ENV->get_object(k)->as_instance_klass();
   589       }
   590     }
   591     // Memoize this result.
   592     if (!is_shared()) {
   593       _implementors[n] = (impl == NULL)? this: impl;
   594     }
   595   } else if (impl == this) {
   596     impl = NULL;  // memoized null result from a VM query
   597   }
   598   return impl;
   599 }

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