jdk8-mips64-public/hotspot: src/share/vm/oops/cpCacheOop.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/cpCacheOop.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/cpCacheOop.cpp

Thu, 07 Apr 2011 09:53:20 -0700

author: johnc
date: Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781: e1162778c1c8
parent 2658: c7f3d0b4570f
child 2742: ed69575596ac
permissions: -rw-r--r--

7009266: G1: assert(obj->is_oop_or_null(true )) failed: Error
Summary: A referent object that is only weakly reachable at the start of concurrent marking but is re-attached to the strongly reachable object graph during marking may not be marked as live. This can cause the reference object to be processed prematurely and leave dangling pointers to the referent object. Implement a read barrier for the java.lang.ref.Reference::referent field by intrinsifying the Reference.get() method, and intercepting accesses though JNI, reflection, and Unsafe, so that when a non-null referent object is read it is also logged in an SATB buffer.
Reviewed-by: kvn, iveresov, never, tonyp, dholmes

 /*
  * Copyright (c) 1998, 2011, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  *
  */
 #include "precompiled.hpp"
 #include "gc_implementation/shared/markSweep.inline.hpp"
 #include "interpreter/interpreter.hpp"
 #include "interpreter/rewriter.hpp"
 #include "memory/universe.inline.hpp"
 #include "oops/cpCacheOop.hpp"
 #include "oops/objArrayOop.hpp"
 #include "oops/oop.inline.hpp"
 #include "prims/jvmtiRedefineClassesTrace.hpp"
 #include "runtime/handles.inline.hpp"
 // Implememtation of ConstantPoolCacheEntry
 void ConstantPoolCacheEntry::initialize_entry(int index) {
   assert(0 < index && index < 0x10000, "sanity check");
   _indices = index;
   assert(constant_pool_index() == index, "");
 }
 void ConstantPoolCacheEntry::initialize_secondary_entry(int main_index) {
   assert(0 <= main_index && main_index < 0x10000, "sanity check");
   _indices = (main_index << 16);
   assert(main_entry_index() == main_index, "");
 }
 int ConstantPoolCacheEntry::as_flags(TosState state, bool is_final,
                     bool is_vfinal, bool is_volatile,
                     bool is_method_interface, bool is_method) {
   int f = state;
   assert( state < number_of_states, "Invalid state in as_flags");
   f <<= 1;
   if (is_final) f |= 1;
   f <<= 1;
   if (is_vfinal) f |= 1;
   f <<= 1;
   if (is_volatile) f |= 1;
   f <<= 1;
   if (is_method_interface) f |= 1;
   f <<= 1;
   if (is_method) f |= 1;
   f <<= ConstantPoolCacheEntry::hotSwapBit;
   // Preserve existing flag bit values
 #ifdef ASSERT
   int old_state = ((_flags >> tosBits) & 0x0F);
   assert(old_state == 0 || old_state == state,
          "inconsistent cpCache flags state");
 #endif
   return (_flags | f) ;
 }
 void ConstantPoolCacheEntry::set_bytecode_1(Bytecodes::Code code) {
 #ifdef ASSERT
   // Read once.
   volatile Bytecodes::Code c = bytecode_1();
   assert(c == 0 || c == code || code == 0, "update must be consistent");
 #endif
   // Need to flush pending stores here before bytecode is written.
   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 16));
 }
 void ConstantPoolCacheEntry::set_bytecode_2(Bytecodes::Code code) {
 #ifdef ASSERT
   // Read once.
   volatile Bytecodes::Code c = bytecode_2();
   assert(c == 0 || c == code || code == 0, "update must be consistent");
 #endif
   // Need to flush pending stores here before bytecode is written.
   OrderAccess::release_store_ptr(&_indices, _indices | ((u_char)code << 24));
 }
 // Atomically sets f1 if it is still NULL, otherwise it keeps the
 // current value.
 void ConstantPoolCacheEntry::set_f1_if_null_atomic(oop f1) {
   // Use barriers as in oop_store
   oop* f1_addr = (oop*) &_f1;
   update_barrier_set_pre(f1_addr, f1);
   void* result = Atomic::cmpxchg_ptr(f1, f1_addr, NULL);
   bool success = (result == NULL);
   if (success) {
     update_barrier_set(f1_addr, f1);
   }
 }
 #ifdef ASSERT
 // It is possible to have two different dummy methodOops created
 // when the resolve code for invoke interface executes concurrently
 // Hence the assertion below is weakened a bit for the invokeinterface
 // case.
 bool ConstantPoolCacheEntry::same_methodOop(oop cur_f1, oop f1) {
   return (cur_f1 == f1 || ((methodOop)cur_f1)->name() ==
          ((methodOop)f1)->name() || ((methodOop)cur_f1)->signature() ==
          ((methodOop)f1)->signature());
 }
 #endif
 // Note that concurrent update of both bytecodes can leave one of them
 // reset to zero.  This is harmless; the interpreter will simply re-resolve
 // the damaged entry.  More seriously, the memory synchronization is needed
 // to flush other fields (f1, f2) completely to memory before the bytecodes
 // are updated, lest other processors see a non-zero bytecode but zero f1/f2.
 void ConstantPoolCacheEntry::set_field(Bytecodes::Code get_code,
                                        Bytecodes::Code put_code,
                                        KlassHandle field_holder,
                                        int orig_field_index,
                                        int field_offset,
                                        TosState field_type,
                                        bool is_final,
                                        bool is_volatile) {
   set_f1(field_holder()->java_mirror());
   set_f2(field_offset);
   // The field index is used by jvm/ti and is the index into fields() array
   // in holder instanceKlass.  This is scaled by instanceKlass::next_offset.
   assert((orig_field_index % instanceKlass::next_offset) == 0, "wierd index");
   const int field_index = orig_field_index / instanceKlass::next_offset;
   assert(field_index <= field_index_mask,
          "field index does not fit in low flag bits");
   set_flags(as_flags(field_type, is_final, false, is_volatile, false, false) |
             (field_index & field_index_mask));
   set_bytecode_1(get_code);
   set_bytecode_2(put_code);
   NOT_PRODUCT(verify(tty));
 }
 int  ConstantPoolCacheEntry::field_index() const {
   return (_flags & field_index_mask) * instanceKlass::next_offset;
 }
 void ConstantPoolCacheEntry::set_method(Bytecodes::Code invoke_code,
                                         methodHandle method,
                                         int vtable_index) {
   assert(!is_secondary_entry(), "");
   assert(method->interpreter_entry() != NULL, "should have been set at this point");
   assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
   bool change_to_virtual = (invoke_code == Bytecodes::_invokeinterface);
   int byte_no = -1;
   bool needs_vfinal_flag = false;
   switch (invoke_code) {
     case Bytecodes::_invokevirtual:
     case Bytecodes::_invokeinterface: {
         if (method->can_be_statically_bound()) {
           set_f2((intptr_t)method());
           needs_vfinal_flag = true;
         } else {
           assert(vtable_index >= 0, "valid index");
           set_f2(vtable_index);
         }
         byte_no = 2;
         break;
     }
     case Bytecodes::_invokedynamic:  // similar to _invokevirtual
       if (TraceInvokeDynamic) {
         tty->print_cr("InvokeDynamic set_method%s method="PTR_FORMAT" index=%d",
                       (is_secondary_entry() ? " secondary" : ""),
                       (intptr_t)method(), vtable_index);
         method->print();
         this->print(tty, 0);
       }
       assert(method->can_be_statically_bound(), "must be a MH invoker method");
       assert(AllowTransitionalJSR292 || _f2 >= constantPoolOopDesc::CPCACHE_INDEX_TAG, "BSM index initialized");
       // SystemDictionary::find_method_handle_invoke only caches
       // methods which signature classes are on the boot classpath,
       // otherwise the newly created method is returned.  To avoid
       // races in that case we store the first one coming in into the
       // cp-cache atomically if it's still unset.
       set_f1_if_null_atomic(method());
       needs_vfinal_flag = false;  // _f2 is not an oop
       assert(!is_vfinal(), "f2 not an oop");
       byte_no = 1;  // coordinate this with bytecode_number & is_resolved
       break;
     case Bytecodes::_invokespecial:
       // Preserve the value of the vfinal flag on invokevirtual bytecode
       // which may be shared with this constant pool cache entry.
       needs_vfinal_flag = is_resolved(Bytecodes::_invokevirtual) && is_vfinal();
       // fall through
     case Bytecodes::_invokestatic:
       set_f1(method());
       byte_no = 1;
       break;
     default:
       ShouldNotReachHere();
       break;
   }
   set_flags(as_flags(as_TosState(method->result_type()),
                      method->is_final_method(),
                      needs_vfinal_flag,
                      false,
                      change_to_virtual,
                      true)|
             method()->size_of_parameters());
   // Note:  byte_no also appears in TemplateTable::resolve.
   if (byte_no == 1) {
     set_bytecode_1(invoke_code);
   } else if (byte_no == 2)  {
     if (change_to_virtual) {
       // NOTE: THIS IS A HACK - BE VERY CAREFUL!!!
       //
       // Workaround for the case where we encounter an invokeinterface, but we
       // should really have an _invokevirtual since the resolved method is a
       // virtual method in java.lang.Object. This is a corner case in the spec
       // but is presumably legal. javac does not generate this code.
       //
       // We set bytecode_1() to _invokeinterface, because that is the
       // bytecode # used by the interpreter to see if it is resolved.
       // We set bytecode_2() to _invokevirtual.
       // See also interpreterRuntime.cpp. (8/25/2000)
       // Only set resolved for the invokeinterface case if method is public.
       // Otherwise, the method needs to be reresolved with caller for each
       // interface call.
       if (method->is_public()) set_bytecode_1(invoke_code);
       set_bytecode_2(Bytecodes::_invokevirtual);
     } else {
       set_bytecode_2(invoke_code);
     }
   } else {
     ShouldNotReachHere();
   }
   NOT_PRODUCT(verify(tty));
 }
 void ConstantPoolCacheEntry::set_interface_call(methodHandle method, int index) {
   assert(!is_secondary_entry(), "");
   klassOop interf = method->method_holder();
   assert(instanceKlass::cast(interf)->is_interface(), "must be an interface");
   set_f1(interf);
   set_f2(index);
   set_flags(as_flags(as_TosState(method->result_type()), method->is_final_method(), false, false, false, true) | method()->size_of_parameters());
   set_bytecode_1(Bytecodes::_invokeinterface);
 }
 void ConstantPoolCacheEntry::initialize_bootstrap_method_index_in_cache(int bsm_cache_index) {
   assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
   assert(_f2 == 0, "initialize once");
   assert(bsm_cache_index == (int)(u2)bsm_cache_index, "oob");
   set_f2(bsm_cache_index + constantPoolOopDesc::CPCACHE_INDEX_TAG);
 }
 int ConstantPoolCacheEntry::bootstrap_method_index_in_cache() {
   assert(!is_secondary_entry(), "only for JVM_CONSTANT_InvokeDynamic main entry");
   intptr_t bsm_cache_index = (intptr_t) _f2 - constantPoolOopDesc::CPCACHE_INDEX_TAG;
   assert(bsm_cache_index == (intptr_t)(u2)bsm_cache_index, "oob");
   return (int) bsm_cache_index;
 }
 void ConstantPoolCacheEntry::set_dynamic_call(Handle call_site,
                                               methodHandle signature_invoker) {
   assert(is_secondary_entry(), "");
   int param_size = signature_invoker->size_of_parameters();
   assert(param_size >= 1, "method argument size must include MH.this");
   param_size -= 1;              // do not count MH.this; it is not stacked for invokedynamic
   if (Atomic::cmpxchg_ptr(call_site(), &_f1, NULL) == NULL) {
     // racing threads might be trying to install their own favorites
     set_f1(call_site());
   }
   bool is_final = true;
   assert(signature_invoker->is_final_method(), "is_final");
   set_flags(as_flags(as_TosState(signature_invoker->result_type()), is_final, false, false, false, true) | param_size);
   // do not do set_bytecode on a secondary CP cache entry
   //set_bytecode_1(Bytecodes::_invokedynamic);
 }
 class LocalOopClosure: public OopClosure {
  private:
   void (*_f)(oop*);
  public:
   LocalOopClosure(void f(oop*))        { _f = f; }
   virtual void do_oop(oop* o)          { _f(o); }
   virtual void do_oop(narrowOop *o)    { ShouldNotReachHere(); }
 };
 void ConstantPoolCacheEntry::oops_do(void f(oop*)) {
   LocalOopClosure blk(f);
   oop_iterate(&blk);
 }
 void ConstantPoolCacheEntry::oop_iterate(OopClosure* blk) {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   blk->do_oop((oop*)&_f1);
   if (is_vfinal()) {
     blk->do_oop((oop*)&_f2);
   }
 }
 void ConstantPoolCacheEntry::oop_iterate_m(OopClosure* blk, MemRegion mr) {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   if (mr.contains((oop *)&_f1)) blk->do_oop((oop*)&_f1);
   if (is_vfinal()) {
     if (mr.contains((oop *)&_f2)) blk->do_oop((oop*)&_f2);
   }
 }
 void ConstantPoolCacheEntry::follow_contents() {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   MarkSweep::mark_and_push((oop*)&_f1);
   if (is_vfinal()) {
     MarkSweep::mark_and_push((oop*)&_f2);
   }
 }
 #ifndef SERIALGC
 void ConstantPoolCacheEntry::follow_contents(ParCompactionManager* cm) {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   PSParallelCompact::mark_and_push(cm, (oop*)&_f1);
   if (is_vfinal()) {
     PSParallelCompact::mark_and_push(cm, (oop*)&_f2);
   }
 }
 #endif // SERIALGC
 void ConstantPoolCacheEntry::adjust_pointers() {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   MarkSweep::adjust_pointer((oop*)&_f1);
   if (is_vfinal()) {
     MarkSweep::adjust_pointer((oop*)&_f2);
   }
 }
 #ifndef SERIALGC
 void ConstantPoolCacheEntry::update_pointers() {
   assert(in_words(size()) == 4, "check code below - may need adjustment");
   // field[1] is always oop or NULL
   PSParallelCompact::adjust_pointer((oop*)&_f1);
   if (is_vfinal()) {
     PSParallelCompact::adjust_pointer((oop*)&_f2);
   }
 }
 #endif // SERIALGC
 // RedefineClasses() API support:
 // If this constantPoolCacheEntry refers to old_method then update it
 // to refer to new_method.
 bool ConstantPoolCacheEntry::adjust_method_entry(methodOop old_method,
        methodOop new_method, bool * trace_name_printed) {
   if (is_vfinal()) {
     // virtual and final so f2() contains method ptr instead of vtable index
     if (f2() == (intptr_t)old_method) {
       // match old_method so need an update
       _f2 = (intptr_t)new_method;
       if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
         if (!(*trace_name_printed)) {
           // RC_TRACE_MESG macro has an embedded ResourceMark
           RC_TRACE_MESG(("adjust: name=%s",
             Klass::cast(old_method->method_holder())->external_name()));
           *trace_name_printed = true;
         }
         // RC_TRACE macro has an embedded ResourceMark
         RC_TRACE(0x00400000, ("cpc vf-entry update: %s(%s)",
           new_method->name()->as_C_string(),
           new_method->signature()->as_C_string()));
       }
       return true;
     }
     // f1() is not used with virtual entries so bail out
     return false;
   }
   if ((oop)_f1 == NULL) {
     // NULL f1() means this is a virtual entry so bail out
     // We are assuming that the vtable index does not need change.
     return false;
   }
   if ((oop)_f1 == old_method) {
     _f1 = new_method;
     if (RC_TRACE_IN_RANGE(0x00100000, 0x00400000)) {
       if (!(*trace_name_printed)) {
         // RC_TRACE_MESG macro has an embedded ResourceMark
         RC_TRACE_MESG(("adjust: name=%s",
           Klass::cast(old_method->method_holder())->external_name()));
         *trace_name_printed = true;
       }
       // RC_TRACE macro has an embedded ResourceMark
       RC_TRACE(0x00400000, ("cpc entry update: %s(%s)",
         new_method->name()->as_C_string(),
         new_method->signature()->as_C_string()));
     }
     return true;
   }
   return false;
 }
 bool ConstantPoolCacheEntry::is_interesting_method_entry(klassOop k) {
   if (!is_method_entry()) {
     // not a method entry so not interesting by default
     return false;
   }
   methodOop m = NULL;
   if (is_vfinal()) {
     // virtual and final so _f2 contains method ptr instead of vtable index
     m = (methodOop)_f2;
   } else if ((oop)_f1 == NULL) {
     // NULL _f1 means this is a virtual entry so also not interesting
     return false;
   } else {
     if (!((oop)_f1)->is_method()) {
       // _f1 can also contain a klassOop for an interface
       return false;
     }
     m = (methodOop)_f1;
   }
   assert(m != NULL && m->is_method(), "sanity check");
   if (m == NULL || !m->is_method() || m->method_holder() != k) {
     // robustness for above sanity checks or method is not in
     // the interesting class
     return false;
   }
   // the method is in the interesting class so the entry is interesting
   return true;
 }
 void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
   // print separator
   if (index == 0) tty->print_cr("                 -------------");
   // print entry
   tty->print("%3d  ("PTR_FORMAT")  ", index, (intptr_t)this);
   if (is_secondary_entry())
     tty->print_cr("[%5d|secondary]", main_entry_index());
   else
     tty->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(), constant_pool_index());
   tty->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)(oop)_f1);
   tty->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_f2);
   tty->print_cr("                 [   "PTR_FORMAT"]", (intptr_t)_flags);
   tty->print_cr("                 -------------");
 }
 void ConstantPoolCacheEntry::verify(outputStream* st) const {
   // not implemented yet
 }
 // Implementation of ConstantPoolCache
 void constantPoolCacheOopDesc::initialize(intArray& inverse_index_map) {
   assert(inverse_index_map.length() == length(), "inverse index map must have same length as cache");
   for (int i = 0; i < length(); i++) {
     ConstantPoolCacheEntry* e = entry_at(i);
     int original_index = inverse_index_map[i];
     if ((original_index & Rewriter::_secondary_entry_tag) != 0) {
       int main_index = (original_index - Rewriter::_secondary_entry_tag);
       assert(!entry_at(main_index)->is_secondary_entry(), "valid main index");
       e->initialize_secondary_entry(main_index);
     } else {
       e->initialize_entry(original_index);
     }
     assert(entry_at(i) == e, "sanity");
   }
 }
 // RedefineClasses() API support:
 // If any entry of this constantPoolCache points to any of
 // old_methods, replace it with the corresponding new_method.
 void constantPoolCacheOopDesc::adjust_method_entries(methodOop* old_methods, methodOop* new_methods,
                                                      int methods_length, bool * trace_name_printed) {
   if (methods_length == 0) {
     // nothing to do if there are no methods
     return;
   }
   // get shorthand for the interesting class
   klassOop old_holder = old_methods[0]->method_holder();
   for (int i = 0; i < length(); i++) {
     if (!entry_at(i)->is_interesting_method_entry(old_holder)) {
       // skip uninteresting methods
       continue;
     }
     // The constantPoolCache contains entries for several different
     // things, but we only care about methods. In fact, we only care
     // about methods in the same class as the one that contains the
     // old_methods. At this point, we have an interesting entry.
     for (int j = 0; j < methods_length; j++) {
       methodOop old_method = old_methods[j];
       methodOop new_method = new_methods[j];
       if (entry_at(i)->adjust_method_entry(old_method, new_method,
           trace_name_printed)) {
         // current old_method matched this entry and we updated it so
         // break out and get to the next interesting entry if there one
         break;
       }
     }
   }
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/oops/cpCacheOop.cpp@e1162778c1c8 (annotated)

src/share/vm/oops/cpCacheOop.cpp