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

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

src/share/vm/oops/instanceRefKlass.cpp

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

author: johnc
date: Thu, 07 Apr 2011 09:53:20 -0700
changeset 2781: e1162778c1c8
parent 2534: e5383553fd4e
child 2909: 2aa9ddbb9e60
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) 1997, 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 "classfile/javaClasses.hpp"
 #include "classfile/systemDictionary.hpp"
 #include "gc_implementation/shared/markSweep.inline.hpp"
 #include "gc_interface/collectedHeap.hpp"
 #include "gc_interface/collectedHeap.inline.hpp"
 #include "memory/genCollectedHeap.hpp"
 #include "memory/genOopClosures.inline.hpp"
 #include "oops/instanceRefKlass.hpp"
 #include "oops/oop.inline.hpp"
 #include "utilities/preserveException.hpp"
 #ifndef SERIALGC
 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
 #include "gc_implementation/g1/g1OopClosures.inline.hpp"
 #include "gc_implementation/g1/g1RemSet.inline.hpp"
 #include "gc_implementation/g1/heapRegionSeq.inline.hpp"
 #include "gc_implementation/parNew/parOopClosures.inline.hpp"
 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
 #include "gc_implementation/parallelScavenge/psScavenge.inline.hpp"
 #include "oops/oop.pcgc.inline.hpp"
 #endif
 template <class T>
 static void specialized_oop_follow_contents(instanceRefKlass* ref, oop obj) {
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
   T heap_oop = oopDesc::load_heap_oop(referent_addr);
   debug_only(
     if(TraceReferenceGC && PrintGCDetails) {
       gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj);
     }
   )
   if (!oopDesc::is_null(heap_oop)) {
     oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
     if (!referent->is_gc_marked() &&
         MarkSweep::ref_processor()->
           discover_reference(obj, ref->reference_type())) {
       // reference already enqueued, referent will be traversed later
       ref->instanceKlass::oop_follow_contents(obj);
       debug_only(
         if(TraceReferenceGC && PrintGCDetails) {
           gclog_or_tty->print_cr("       Non NULL enqueued " INTPTR_FORMAT, obj);
         }
       )
       return;
     } else {
       // treat referent as normal oop
       debug_only(
         if(TraceReferenceGC && PrintGCDetails) {
           gclog_or_tty->print_cr("       Non NULL normal " INTPTR_FORMAT, obj);
         }
       )
       MarkSweep::mark_and_push(referent_addr);
     }
   }
   // treat next as normal oop.  next is a link in the pending list.
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
   debug_only(
     if(TraceReferenceGC && PrintGCDetails) {
       gclog_or_tty->print_cr("   Process next as normal " INTPTR_FORMAT, next_addr);
     }
   )
   MarkSweep::mark_and_push(next_addr);
   ref->instanceKlass::oop_follow_contents(obj);
 }
 void instanceRefKlass::oop_follow_contents(oop obj) {
   if (UseCompressedOops) {
     specialized_oop_follow_contents<narrowOop>(this, obj);
   } else {
     specialized_oop_follow_contents<oop>(this, obj);
   }
 }
 #ifndef SERIALGC
 template <class T>
 void specialized_oop_follow_contents(instanceRefKlass* ref,
                                      ParCompactionManager* cm,
                                      oop obj) {
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
   T heap_oop = oopDesc::load_heap_oop(referent_addr);
   debug_only(
     if(TraceReferenceGC && PrintGCDetails) {
       gclog_or_tty->print_cr("instanceRefKlass::oop_follow_contents " INTPTR_FORMAT, obj);
     }
   )
   if (!oopDesc::is_null(heap_oop)) {
     oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);
     if (PSParallelCompact::mark_bitmap()->is_unmarked(referent) &&
         PSParallelCompact::ref_processor()->
           discover_reference(obj, ref->reference_type())) {
       // reference already enqueued, referent will be traversed later
       ref->instanceKlass::oop_follow_contents(cm, obj);
       debug_only(
         if(TraceReferenceGC && PrintGCDetails) {
           gclog_or_tty->print_cr("       Non NULL enqueued " INTPTR_FORMAT, obj);
         }
       )
       return;
     } else {
       // treat referent as normal oop
       debug_only(
         if(TraceReferenceGC && PrintGCDetails) {
           gclog_or_tty->print_cr("       Non NULL normal " INTPTR_FORMAT, obj);
         }
       )
       PSParallelCompact::mark_and_push(cm, referent_addr);
     }
   }
   // treat next as normal oop.  next is a link in the pending list.
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
   debug_only(
     if(TraceReferenceGC && PrintGCDetails) {
       gclog_or_tty->print_cr("   Process next as normal " INTPTR_FORMAT, next_addr);
     }
   )
   PSParallelCompact::mark_and_push(cm, next_addr);
   ref->instanceKlass::oop_follow_contents(cm, obj);
 }
 void instanceRefKlass::oop_follow_contents(ParCompactionManager* cm,
                                            oop obj) {
   if (UseCompressedOops) {
     specialized_oop_follow_contents<narrowOop>(this, cm, obj);
   } else {
     specialized_oop_follow_contents<oop>(this, cm, obj);
   }
 }
 #endif // SERIALGC
 #ifdef ASSERT
 template <class T> void trace_reference_gc(const char *s, oop obj,
                                            T* referent_addr,
                                            T* next_addr,
                                            T* discovered_addr) {
   if(TraceReferenceGC && PrintGCDetails) {
     gclog_or_tty->print_cr("%s obj " INTPTR_FORMAT, s, (address)obj);
     gclog_or_tty->print_cr("     referent_addr/* " INTPTR_FORMAT " / "
          INTPTR_FORMAT, referent_addr,
          referent_addr ?
            (address)oopDesc::load_decode_heap_oop(referent_addr) : NULL);
     gclog_or_tty->print_cr("     next_addr/* " INTPTR_FORMAT " / "
          INTPTR_FORMAT, next_addr,
          next_addr ? (address)oopDesc::load_decode_heap_oop(next_addr) : NULL);
     gclog_or_tty->print_cr("     discovered_addr/* " INTPTR_FORMAT " / "
          INTPTR_FORMAT, discovered_addr,
          discovered_addr ?
            (address)oopDesc::load_decode_heap_oop(discovered_addr) : NULL);
   }
 }
 #endif
 template <class T> void specialized_oop_adjust_pointers(instanceRefKlass *ref, oop obj) {
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
   MarkSweep::adjust_pointer(referent_addr);
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
   MarkSweep::adjust_pointer(next_addr);
   T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
   MarkSweep::adjust_pointer(discovered_addr);
   debug_only(trace_reference_gc("instanceRefKlass::oop_adjust_pointers", obj,
                                 referent_addr, next_addr, discovered_addr);)
 }
 int instanceRefKlass::oop_adjust_pointers(oop obj) {
   int size = size_helper();
   instanceKlass::oop_adjust_pointers(obj);
   if (UseCompressedOops) {
     specialized_oop_adjust_pointers<narrowOop>(this, obj);
   } else {
     specialized_oop_adjust_pointers<oop>(this, obj);
   }
   return size;
 }
 #define InstanceRefKlass_SPECIALIZED_OOP_ITERATE(T, nv_suffix, contains)        \
   if (closure->apply_to_weak_ref_discovered_field()) {                          \
     T* disc_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);           \
     closure->do_oop##nv_suffix(disc_addr);                                      \
   }                                                                             \
                                                                                 \
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);           \
   T heap_oop = oopDesc::load_heap_oop(referent_addr);                           \
   if (!oopDesc::is_null(heap_oop) && contains(referent_addr)) {                 \
     ReferenceProcessor* rp = closure->_ref_processor;                           \
     oop referent = oopDesc::decode_heap_oop_not_null(heap_oop);                 \
     if (!referent->is_gc_marked() && (rp != NULL) &&                            \
         rp->discover_reference(obj, reference_type())) {                        \
       return size;                                                              \
     } else {                                                                    \
       /* treat referent as normal oop */                                        \
       SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk);\
       closure->do_oop##nv_suffix(referent_addr);                                \
     }                                                                           \
   }                                                                             \
   /* treat next as normal oop */                                                \
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);                   \
   if (contains(next_addr)) {                                                    \
     SpecializationStats::record_do_oop_call##nv_suffix(SpecializationStats::irk); \
     closure->do_oop##nv_suffix(next_addr);                                      \
   }                                                                             \
   return size;                                                                  \
 template <class T> bool contains(T *t) { return true; }
 // Macro to define instanceRefKlass::oop_oop_iterate for virtual/nonvirtual for
 // all closures.  Macros calling macros above for each oop size.
 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)        \
                                                                                 \
 int instanceRefKlass::                                                          \
 oop_oop_iterate##nv_suffix(oop obj, OopClosureType* closure) {                  \
   /* Get size before changing pointers */                                       \
   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
                                                                                 \
   int size = instanceKlass::oop_oop_iterate##nv_suffix(obj, closure);           \
                                                                                 \
   if (UseCompressedOops) {                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains);   \
   } else {                                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains);         \
   }                                                                             \
 }
 #ifndef SERIALGC
 #define InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN(OopClosureType, nv_suffix) \
                                                                                 \
 int instanceRefKlass::                                                          \
 oop_oop_iterate_backwards##nv_suffix(oop obj, OopClosureType* closure) {        \
   /* Get size before changing pointers */                                       \
   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
                                                                                 \
   int size = instanceKlass::oop_oop_iterate_backwards##nv_suffix(obj, closure); \
                                                                                 \
   if (UseCompressedOops) {                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, contains);   \
   } else {                                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, contains);         \
   }                                                                             \
 }
 #endif // !SERIALGC
 #define InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m(OopClosureType, nv_suffix)      \
                                                                                 \
 int instanceRefKlass::                                                          \
 oop_oop_iterate##nv_suffix##_m(oop obj,                                         \
                                OopClosureType* closure,                         \
                                MemRegion mr) {                                  \
   SpecializationStats::record_iterate_call##nv_suffix(SpecializationStats::irk);\
                                                                                 \
   int size = instanceKlass::oop_oop_iterate##nv_suffix##_m(obj, closure, mr);   \
   if (UseCompressedOops) {                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(narrowOop, nv_suffix, mr.contains); \
   } else {                                                                      \
     InstanceRefKlass_SPECIALIZED_OOP_ITERATE(oop, nv_suffix, mr.contains);      \
   }                                                                             \
 }
 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN)
 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN)
 #ifndef SERIALGC
 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_BACKWARDS_DEFN)
 #endif // SERIALGC
 ALL_OOP_OOP_ITERATE_CLOSURES_1(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m)
 ALL_OOP_OOP_ITERATE_CLOSURES_2(InstanceRefKlass_OOP_OOP_ITERATE_DEFN_m)
 #ifndef SERIALGC
 template <class T>
 void specialized_oop_push_contents(instanceRefKlass *ref,
                                    PSPromotionManager* pm, oop obj) {
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
   if (PSScavenge::should_scavenge(referent_addr)) {
     ReferenceProcessor* rp = PSScavenge::reference_processor();
     if (rp->discover_reference(obj, ref->reference_type())) {
       // reference already enqueued, referent and next will be traversed later
       ref->instanceKlass::oop_push_contents(pm, obj);
       return;
     } else {
       // treat referent as normal oop
       pm->claim_or_forward_depth(referent_addr);
     }
   }
   // treat next as normal oop
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
   if (PSScavenge::should_scavenge(next_addr)) {
     pm->claim_or_forward_depth(next_addr);
   }
   ref->instanceKlass::oop_push_contents(pm, obj);
 }
 void instanceRefKlass::oop_push_contents(PSPromotionManager* pm, oop obj) {
   if (UseCompressedOops) {
     specialized_oop_push_contents<narrowOop>(this, pm, obj);
   } else {
     specialized_oop_push_contents<oop>(this, pm, obj);
   }
 }
 template <class T>
 void specialized_oop_update_pointers(instanceRefKlass *ref,
                                     ParCompactionManager* cm, oop obj) {
   T* referent_addr = (T*)java_lang_ref_Reference::referent_addr(obj);
   PSParallelCompact::adjust_pointer(referent_addr);
   T* next_addr = (T*)java_lang_ref_Reference::next_addr(obj);
   PSParallelCompact::adjust_pointer(next_addr);
   T* discovered_addr = (T*)java_lang_ref_Reference::discovered_addr(obj);
   PSParallelCompact::adjust_pointer(discovered_addr);
   debug_only(trace_reference_gc("instanceRefKlass::oop_update_ptrs", obj,
                                 referent_addr, next_addr, discovered_addr);)
 }
 int instanceRefKlass::oop_update_pointers(ParCompactionManager* cm, oop obj) {
   instanceKlass::oop_update_pointers(cm, obj);
   if (UseCompressedOops) {
     specialized_oop_update_pointers<narrowOop>(this, cm, obj);
   } else {
     specialized_oop_update_pointers<oop>(this, cm, obj);
   }
   return size_helper();
 }
 #endif // SERIALGC
 void instanceRefKlass::update_nonstatic_oop_maps(klassOop k) {
   // Clear the nonstatic oop-map entries corresponding to referent
   // and nextPending field.  They are treated specially by the
   // garbage collector.
   // The discovered field is used only by the garbage collector
   // and is also treated specially.
   instanceKlass* ik = instanceKlass::cast(k);
   // Check that we have the right class
   debug_only(static bool first_time = true);
   assert(k == SystemDictionary::Reference_klass() && first_time,
          "Invalid update of maps");
   debug_only(first_time = false);
   assert(ik->nonstatic_oop_map_count() == 1, "just checking");
   OopMapBlock* map = ik->start_of_nonstatic_oop_maps();
   // Check that the current map is (2,4) - currently points at field with
   // offset 2 (words) and has 4 map entries.
   debug_only(int offset = java_lang_ref_Reference::referent_offset);
   debug_only(unsigned int count = ((java_lang_ref_Reference::discovered_offset -
     java_lang_ref_Reference::referent_offset)/heapOopSize) + 1);
   if (UseSharedSpaces) {
     assert(map->offset() == java_lang_ref_Reference::queue_offset &&
            map->count() == 1, "just checking");
   } else {
     assert(map->offset() == offset && map->count() == count,
            "just checking");
     // Update map to (3,1) - point to offset of 3 (words) with 1 map entry.
     map->set_offset(java_lang_ref_Reference::queue_offset);
     map->set_count(1);
   }
 }
 // Verification
 void instanceRefKlass::oop_verify_on(oop obj, outputStream* st) {
   instanceKlass::oop_verify_on(obj, st);
   // Verify referent field
   oop referent = java_lang_ref_Reference::referent(obj);
   // We should make this general to all heaps
   GenCollectedHeap* gch = NULL;
   if (Universe::heap()->kind() == CollectedHeap::GenCollectedHeap)
     gch = GenCollectedHeap::heap();
   if (referent != NULL) {
     guarantee(referent->is_oop(), "referent field heap failed");
     if (gch != NULL && !gch->is_in_youngest(obj)) {
       // We do a specific remembered set check here since the referent
       // field is not part of the oop mask and therefore skipped by the
       // regular verify code.
       if (UseCompressedOops) {
         narrowOop* referent_addr = (narrowOop*)java_lang_ref_Reference::referent_addr(obj);
         obj->verify_old_oop(referent_addr, true);
       } else {
         oop* referent_addr = (oop*)java_lang_ref_Reference::referent_addr(obj);
         obj->verify_old_oop(referent_addr, true);
       }
     }
   }
   // Verify next field
   oop next = java_lang_ref_Reference::next(obj);
   if (next != NULL) {
     guarantee(next->is_oop(), "next field verify failed");
     guarantee(next->is_instanceRef(), "next field verify failed");
     if (gch != NULL && !gch->is_in_youngest(obj)) {
       // We do a specific remembered set check here since the next field is
       // not part of the oop mask and therefore skipped by the regular
       // verify code.
       if (UseCompressedOops) {
         narrowOop* next_addr = (narrowOop*)java_lang_ref_Reference::next_addr(obj);
         obj->verify_old_oop(next_addr, true);
       } else {
         oop* next_addr = (oop*)java_lang_ref_Reference::next_addr(obj);
         obj->verify_old_oop(next_addr, true);
       }
     }
   }
 }
 bool instanceRefKlass::owns_pending_list_lock(JavaThread* thread) {
   if (java_lang_ref_Reference::pending_list_lock() == NULL) return false;
   Handle h_lock(thread, java_lang_ref_Reference::pending_list_lock());
   return ObjectSynchronizer::current_thread_holds_lock(thread, h_lock);
 }
 void instanceRefKlass::acquire_pending_list_lock(BasicLock *pending_list_basic_lock) {
   // we may enter this with pending exception set
   PRESERVE_EXCEPTION_MARK;  // exceptions are never thrown, needed for TRAPS argument
   Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock());
   ObjectSynchronizer::fast_enter(h_lock, pending_list_basic_lock, false, THREAD);
   assert(ObjectSynchronizer::current_thread_holds_lock(
            JavaThread::current(), h_lock),
          "Locking should have succeeded");
   if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION;
 }
 void instanceRefKlass::release_and_notify_pending_list_lock(
   BasicLock *pending_list_basic_lock) {
   // we may enter this with pending exception set
   PRESERVE_EXCEPTION_MARK;  // exceptions are never thrown, needed for TRAPS argument
   //
   Handle h_lock(THREAD, java_lang_ref_Reference::pending_list_lock());
   assert(ObjectSynchronizer::current_thread_holds_lock(
            JavaThread::current(), h_lock),
          "Lock should be held");
   // Notify waiters on pending lists lock if there is any reference.
   if (java_lang_ref_Reference::pending_list() != NULL) {
     ObjectSynchronizer::notifyall(h_lock, THREAD);
   }
   ObjectSynchronizer::fast_exit(h_lock(), pending_list_basic_lock, THREAD);
   if (HAS_PENDING_EXCEPTION) CLEAR_PENDING_EXCEPTION;
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

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

src/share/vm/oops/instanceRefKlass.cpp