Esempio n. 1
0
int vframeArrayElement::on_stack_size(int callee_parameters,
                                      int callee_locals,
                                      bool is_top_frame,
                                      int popframe_extra_stack_expression_els) const {
  assert(method()->max_locals() == locals()->size(), "just checking");
  int locks = monitors() == NULL ? 0 : monitors()->number_of_monitors();
  int temps = expressions()->size();
  return Interpreter::size_activation(method()->max_stack(),
                                      temps + callee_parameters,
                                      popframe_extra_stack_expression_els,
                                      locks,
                                      callee_parameters,
                                      callee_locals,
                                      is_top_frame);
}
Esempio n. 2
0
void javaVFrame::print() {
  ResourceMark rm;
  vframe::print();
  tty->print("\t");
  method()->print_value();
  tty->cr();
  tty->print_cr("\tbci:    %d", bci());

  print_stack_values("locals",      locals());
  print_stack_values("expressions", expressions());

  GrowableArray<MonitorInfo*>* list = monitors();
  if (list->is_empty()) return;
  tty->print_cr("\tmonitor list:");
  for (int index = (list->length()-1); index >= 0; index--) {
    MonitorInfo* monitor = list->at(index);
    tty->print("\t  obj\t");
    if (monitor->owner_is_scalar_replaced()) {
      Klass* k = java_lang_Class::as_Klass(monitor->owner_klass());
      tty->print("( is scalar replaced %s)", k->external_name());
    } else if (monitor->owner() == NULL) {
      tty->print("( null )");
    } else {
      monitor->owner()->print_value();
      tty->print("(" INTPTR_FORMAT ")", (address)monitor->owner());
    }
    if (monitor->eliminated() && is_compiled_frame())
      tty->print(" ( lock is eliminated )");
    tty->cr();
    tty->print("\t  ");
    monitor->lock()->print_on(tty);
    tty->cr();
  }
}
Esempio n. 3
0
GrowableArray<MonitorInfo*>* javaVFrame::locked_monitors() {
  assert(SafepointSynchronize::is_at_safepoint() || JavaThread::current() == thread(),
         "must be at safepoint or it's a java frame of the current thread");

  GrowableArray<MonitorInfo*>* mons = monitors();
  GrowableArray<MonitorInfo*>* result = new GrowableArray<MonitorInfo*>(mons->length());
  if (mons->is_empty()) return result;

  bool found_first_monitor = false;
  ObjectMonitor *pending_monitor = thread()->current_pending_monitor();
  ObjectMonitor *waiting_monitor = thread()->current_waiting_monitor();
  oop pending_obj = (pending_monitor != NULL ? (oop) pending_monitor->object() : (oop) NULL);
  oop waiting_obj = (waiting_monitor != NULL ? (oop) waiting_monitor->object() : (oop) NULL);

  for (int index = (mons->length()-1); index >= 0; index--) {
    MonitorInfo* monitor = mons->at(index);
    if (monitor->eliminated() && is_compiled_frame()) continue; // skip eliminated monitor
    oop obj = monitor->owner();
    if (obj == NULL) continue; // skip unowned monitor
    //
    // Skip the monitor that the thread is blocked to enter or waiting on
    //
    if (!found_first_monitor && (obj == pending_obj || obj == waiting_obj)) {
      continue;
    }
    found_first_monitor = true;
    result->append(monitor);
  }
  return result;
}
/**
 * Load monitors data found in nexus file
 *
 * @param entry :: The Nexus entry
 *
 */
std::vector<std::vector<int>>
LoadILLReflectometry::loadMonitors(NeXus::NXEntry &entry) {
  // read in the data
  g_log.debug("Fetching monitor data...");

  NXData dataGroup = entry.openNXData("monitor1/data");
  NXInt data = dataGroup.openIntData();
  // load the counts from the file into memory
  data.load();

  std::vector<std::vector<int>> monitors(
      1); // vector of monitors with one entry
  std::vector<int> monitor1(data(), data() + data.size());
  monitors[0].swap(monitor1);

  // There is two monitors in data file, but the second one seems to be always 0
  dataGroup = entry.openNXData("monitor2/data");
  data = dataGroup.openIntData();
  data.load();

  std::vector<int> monitor2(data(), data() + data.size());
  monitors.push_back(monitor2);

  return monitors;
}
Esempio n. 5
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void javaVFrame::print_lock_info(int frame_count) {        
  ResourceMark rm;

  // If this is the first frame, and java.lang.Object.wait(...) then print out the receiver.
  if (frame_count == 0 && method()->name() == vmSymbols::wait_name() && 
      instanceKlass::cast(method()->method_holder())->name() == vmSymbols::java_lang_Object()) {
    StackValueCollection* locs = locals();      
    if (!locs->is_empty()) {
      StackValue* sv = locs->at(0);
      if (sv->type() == T_OBJECT) {
        Handle o = locs->at(0)->get_obj();    
        if (o.not_null()) {
          instanceKlass* ik = instanceKlass::cast(o->klass());
          tty->print_cr("\t- waiting on <" INTPTR_FORMAT "> (a %s)", o(), ik->external_name());
        }
      }
    }        
  }    
  
  // Print out all monitors that we have locked or are trying to lock
  GrowableArray<MonitorInfo*>* mons = monitors();
  if (!mons->is_empty()) {
    bool found_first_monitor = false;
    for (int index = (mons->length()-1); index >= 0; index--) {
      MonitorInfo* monitor = mons->at(index);
      if (monitor->owner() != NULL) {
        //
        // First, assume we have the monitor locked. If we haven't found an
        // owned monitor before and this is the first frame, then we need to
        // see if the thread is blocked.
        //
        const char *lock_state = "locked"; // assume we have the monitor locked
        if (!found_first_monitor && frame_count == 0) {
          switch (thread()->thread_state()) {
          case _thread_blocked:
          case _thread_blocked_trans:
            lock_state = "waiting to lock";
            break;
          }
        }
        found_first_monitor = true;
        instanceKlass* ik = instanceKlass::cast(monitor->owner()->klass());
        tty->print_cr("\t- %s <" INTPTR_FORMAT "> (a %s)", lock_state, monitor->owner(), ik->external_name());
      }
    }  
  }
}
Esempio n. 6
0
/**
   * Load monitors data found in nexus file
   *
   * @param entry :: The Nexus entry
   *
   */
std::vector<std::vector<int>>
LoadILLIndirect::loadMonitors(NeXus::NXEntry &entry) {
  // read in the data
  g_log.debug("Fetching monitor data...");

  NXData dataGroup = entry.openNXData("monitor/data");
  NXInt data = dataGroup.openIntData();
  // load the counts from the file into memory
  data.load();

  // For the moment, we are aware of only one monitor entry, but we keep the
  // generalized case of n monitors

  std::vector<std::vector<int>> monitors(1);
  std::vector<int> monitor(data(), data() + data.size());
  monitors[0].swap(monitor);
  return monitors;
}
Esempio n. 7
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//
// Count the number of entries for a lightweight monitor. The hobj
// parameter is object that owns the monitor so this routine will
// count the number of times the same object was locked by this
// frame.
//
jint javaVFrame::count_lock_entries(Handle hobj) {
  ResourceMark rm;

  GrowableArray<MonitorInfo*>* mons = monitors();
  if (mons->is_empty()) {
    return 0;  // this javaVFrame holds no monitors
  }

  jint ret = 0;
  for (int i = 0; i < mons->length(); i++) {
    MonitorInfo *mi = mons->at(i);

    // see if owner of the monitor is our object
    if (mi->owner() != NULL && mi->owner() == hobj()) {
      ret++;
    }
  }

  return ret;
}
Esempio n. 8
0
//
// Fabricate heavyweight monitor information for each lightweight monitor
// found in the Java VFrame.
//
void javaVFrame::jvmpi_fab_heavy_monitors(bool query, int* fab_index, int frame_count, GrowableArray<ObjectMonitor*>* fab_list) {
  assert(SafepointSynchronize::is_at_safepoint(), "must be at safepoint");
  ResourceMark rm;

  GrowableArray<MonitorInfo*>* mons = monitors();
  if (mons->is_empty()) return;

  bool found_first_monitor = false;
  for (int index = (mons->length()-1); index >= 0; index--) {
    MonitorInfo* monitor = mons->at(index);
    if (monitor->owner() == NULL) continue; // skip unowned monitor
    //
    // If we haven't found a monitor before, this is the first frame, and
    // the thread is blocked, then we are trying to enter this monitor.
    // We skip it because we have already seen it before from the monitor 
    // cache walk.
    //
    if (!found_first_monitor && frame_count == 0) {
      switch (thread()->thread_state()) {
      case _thread_blocked:
      case _thread_blocked_trans:
        continue;
      }
    }
    found_first_monitor = true;

    markOop mark = monitor->owner()->mark();
    if (mark->has_locker()) {
      if (!query) {   // not just counting so create and store at the current element
        // fabricate the heavyweight monitor from lightweight info
        ObjectMonitor *heavy = new ObjectMonitor();
        heavy->set_object(monitor->owner());  // use the owning object
        heavy->set_owner(thread());           // use thread instead of stack address for speed
        fab_list->at_put(*fab_index, heavy);
      }
      (*fab_index)++;
    }
  }
}
Esempio n. 9
0
void javaVFrame::print() {
  ResourceMark rm;
  vframe::print();
  tty->print("\t"); 
  method()->print_value();
  tty->cr();
  tty->print_cr("\tbci:    %d", bci());

  print_stack_values("locals",      locals());
  print_stack_values("expressions", expressions());

  GrowableArray<MonitorInfo*>* list = monitors();
  if (list->is_empty()) return;
  tty->print_cr("\tmonitor list:");
  for (int index = (list->length()-1); index >= 0; index--) {
    MonitorInfo* monitor = list->at(index);
    tty->print("\t  obj\t"); monitor->owner()->print_value(); 
    tty->print("(" INTPTR_FORMAT ")", monitor->owner());
    tty->cr();
    tty->print("\t  ");
    monitor->lock()->print_on(tty);
    tty->cr(); 
  }
}
Esempio n. 10
0
void javaVFrame::print_lock_info_on(outputStream* st, int frame_count) {
  ResourceMark rm;

  // If this is the first frame, and java.lang.Object.wait(...) then print out the receiver.
  if (frame_count == 0) {
    if (method()->name() == vmSymbols::wait_name() &&
        method()->method_holder()->name() == vmSymbols::java_lang_Object()) {
      StackValueCollection* locs = locals();
      if (!locs->is_empty()) {
        StackValue* sv = locs->at(0);
        if (sv->type() == T_OBJECT) {
          Handle o = locs->at(0)->get_obj();
          print_locked_object_class_name(st, o, "waiting on");
        }
      }
    } else if (thread()->current_park_blocker() != NULL) {
      oop obj = thread()->current_park_blocker();
      Klass* k = obj->klass();
      st->print_cr("\t- %s <" INTPTR_FORMAT "> (a %s)", "parking to wait for ", (address)obj, k->external_name());
    }
  }


  // Print out all monitors that we have locked or are trying to lock
  GrowableArray<MonitorInfo*>* mons = monitors();
  if (!mons->is_empty()) {
    bool found_first_monitor = false;
    for (int index = (mons->length()-1); index >= 0; index--) {
      MonitorInfo* monitor = mons->at(index);
      if (monitor->eliminated() && is_compiled_frame()) { // Eliminated in compiled code
        if (monitor->owner_is_scalar_replaced()) {
          Klass* k = java_lang_Class::as_Klass(monitor->owner_klass());
          st->print("\t- eliminated <owner is scalar replaced> (a %s)", k->external_name());
        } else {
          oop obj = monitor->owner();
          if (obj != NULL) {
            print_locked_object_class_name(st, obj, "eliminated");
          }
        }
        continue;
      }
      if (monitor->owner() != NULL) {

        // First, assume we have the monitor locked. If we haven't found an
        // owned monitor before and this is the first frame, then we need to
        // see if we have completed the lock or we are blocked trying to
        // acquire it - we can only be blocked if the monitor is inflated

        const char *lock_state = "locked"; // assume we have the monitor locked
        if (!found_first_monitor && frame_count == 0) {
          markOop mark = monitor->owner()->mark();
          if (mark->has_monitor() &&
              mark->monitor() == thread()->current_pending_monitor()) {
            lock_state = "waiting to lock";
          }
        }

        found_first_monitor = true;
        print_locked_object_class_name(st, monitor->owner(), lock_state);
      }
    }
  }
}
Esempio n. 11
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 // Tells whether the addr point into the monitors.
 bool contains(void* addr) const           { return (addr >= (void*) monitors()) && (addr <  (void*) (monitors() + number_of_monitors())); }
Esempio n. 12
0
 // Returns the index'th monitor
 BasicObjectLock* at(int index)            { assert(index >= 0 && index < number_of_monitors(), "out of bounds check"); return &monitors()[index]; }
void vframeArrayElement::unpack_on_stack(int caller_actual_parameters,
                                         int callee_parameters,
                                         int callee_locals,
                                         frame* caller,
                                         bool is_top_frame,
                                         bool is_bottom_frame,
                                         int exec_mode) {
  JavaThread* thread = (JavaThread*) Thread::current();

  // Look at bci and decide on bcp and continuation pc
  address bcp;
  // C++ interpreter doesn't need a pc since it will figure out what to do when it
  // begins execution
  address pc;
  bool use_next_mdp = false; // true if we should use the mdp associated with the next bci
                             // rather than the one associated with bcp
  if (raw_bci() == SynchronizationEntryBCI) {
    // We are deoptimizing while hanging in prologue code for synchronized method
    bcp = method()->bcp_from(0); // first byte code
    pc  = Interpreter::deopt_entry(vtos, 0); // step = 0 since we don't skip current bytecode
  } else if (should_reexecute()) { //reexecute this bytecode
    assert(is_top_frame, "reexecute allowed only for the top frame");
    bcp = method()->bcp_from(bci());
    pc  = Interpreter::deopt_reexecute_entry(method(), bcp);
  } else {
    bcp = method()->bcp_from(bci());
    pc  = Interpreter::deopt_continue_after_entry(method(), bcp, callee_parameters, is_top_frame);
    use_next_mdp = true;
  }
  assert(Bytecodes::is_defined(*bcp), "must be a valid bytecode");

  // Monitorenter and pending exceptions:
  //
  // For Compiler2, there should be no pending exception when deoptimizing at monitorenter
  // because there is no safepoint at the null pointer check (it is either handled explicitly
  // or prior to the monitorenter) and asynchronous exceptions are not made "pending" by the
  // runtime interface for the slow case (see JRT_ENTRY_FOR_MONITORENTER).  If an asynchronous
  // exception was processed, the bytecode pointer would have to be extended one bytecode beyond
  // the monitorenter to place it in the proper exception range.
  //
  // For Compiler1, deoptimization can occur while throwing a NullPointerException at monitorenter,
  // in which case bcp should point to the monitorenter since it is within the exception's range.

  assert(*bcp != Bytecodes::_monitorenter || is_top_frame, "a _monitorenter must be a top frame");
  assert(thread->deopt_nmethod() != NULL, "nmethod should be known");
  guarantee(!(thread->deopt_nmethod()->is_compiled_by_c2() &&
              *bcp == Bytecodes::_monitorenter             &&
              exec_mode == Deoptimization::Unpack_exception),
            "shouldn't get exception during monitorenter");

  int popframe_preserved_args_size_in_bytes = 0;
  int popframe_preserved_args_size_in_words = 0;
  if (is_top_frame) {
    JvmtiThreadState *state = thread->jvmti_thread_state();
    if (JvmtiExport::can_pop_frame() &&
        (thread->has_pending_popframe() || thread->popframe_forcing_deopt_reexecution())) {
      if (thread->has_pending_popframe()) {
        // Pop top frame after deoptimization
#ifndef CC_INTERP
        pc = Interpreter::remove_activation_preserving_args_entry();
#else
        // Do an uncommon trap type entry. c++ interpreter will know
        // to pop frame and preserve the args
        pc = Interpreter::deopt_entry(vtos, 0);
        use_next_mdp = false;
#endif
      } else {
        // Reexecute invoke in top frame
        pc = Interpreter::deopt_entry(vtos, 0);
        use_next_mdp = false;
        popframe_preserved_args_size_in_bytes = in_bytes(thread->popframe_preserved_args_size());
        // Note: the PopFrame-related extension of the expression stack size is done in
        // Deoptimization::fetch_unroll_info_helper
        popframe_preserved_args_size_in_words = in_words(thread->popframe_preserved_args_size_in_words());
      }
    } else if (JvmtiExport::can_force_early_return() && state != NULL && state->is_earlyret_pending()) {
      // Force early return from top frame after deoptimization
#ifndef CC_INTERP
      pc = Interpreter::remove_activation_early_entry(state->earlyret_tos());
#else
     // TBD: Need to implement ForceEarlyReturn for CC_INTERP (ia64)
#endif
    } else {
      // Possibly override the previous pc computation of the top (youngest) frame
      switch (exec_mode) {
      case Deoptimization::Unpack_deopt:
        // use what we've got
        break;
      case Deoptimization::Unpack_exception:
        // exception is pending
        pc = SharedRuntime::raw_exception_handler_for_return_address(thread, pc);
        // [phh] We're going to end up in some handler or other, so it doesn't
        // matter what mdp we point to.  See exception_handler_for_exception()
        // in interpreterRuntime.cpp.
        break;
      case Deoptimization::Unpack_uncommon_trap:
      case Deoptimization::Unpack_reexecute:
        // redo last byte code
        pc  = Interpreter::deopt_entry(vtos, 0);
        use_next_mdp = false;
        break;
      default:
        ShouldNotReachHere();
      }
    }
  }

  // Setup the interpreter frame

  assert(method() != NULL, "method must exist");
  int temps = expressions()->size();

  int locks = monitors() == NULL ? 0 : monitors()->number_of_monitors();

  Interpreter::layout_activation(method(),
                                 temps + callee_parameters,
                                 popframe_preserved_args_size_in_words,
                                 locks,
                                 caller_actual_parameters,
                                 callee_parameters,
                                 callee_locals,
                                 caller,
                                 iframe(),
                                 is_top_frame,
                                 is_bottom_frame);

  // Update the pc in the frame object and overwrite the temporary pc
  // we placed in the skeletal frame now that we finally know the
  // exact interpreter address we should use.

  _frame.patch_pc(thread, pc);

  assert (!method()->is_synchronized() || locks > 0, "synchronized methods must have monitors");

  BasicObjectLock* top = iframe()->interpreter_frame_monitor_begin();
  for (int index = 0; index < locks; index++) {
    top = iframe()->previous_monitor_in_interpreter_frame(top);
    BasicObjectLock* src = _monitors->at(index);
    top->set_obj(src->obj());
    src->lock()->move_to(src->obj(), top->lock());
  }
  if (ProfileInterpreter) {
    iframe()->interpreter_frame_set_mdx(0); // clear out the mdp.
  }
  iframe()->interpreter_frame_set_bcx((intptr_t)bcp); // cannot use bcp because frame is not initialized yet
  if (ProfileInterpreter) {
    methodDataOop mdo = method()->method_data();
    if (mdo != NULL) {
      int bci = iframe()->interpreter_frame_bci();
      if (use_next_mdp) ++bci;
      address mdp = mdo->bci_to_dp(bci);
      iframe()->interpreter_frame_set_mdp(mdp);
    }
  }

  // Unpack expression stack
  // If this is an intermediate frame (i.e. not top frame) then this
  // only unpacks the part of the expression stack not used by callee
  // as parameters. The callee parameters are unpacked as part of the
  // callee locals.
  int i;
  for(i = 0; i < expressions()->size(); i++) {
    StackValue *value = expressions()->at(i);
    intptr_t*   addr  = iframe()->interpreter_frame_expression_stack_at(i);
    switch(value->type()) {
      case T_INT:
        *addr = value->get_int();
        break;
      case T_OBJECT:
        *addr = value->get_int(T_OBJECT);
        break;
      case T_CONFLICT:
        // A dead stack slot.  Initialize to null in case it is an oop.
        *addr = NULL_WORD;
        break;
      default:
        ShouldNotReachHere();
    }
  }


  // Unpack the locals
  for(i = 0; i < locals()->size(); i++) {
    StackValue *value = locals()->at(i);
    intptr_t* addr  = iframe()->interpreter_frame_local_at(i);
    switch(value->type()) {
      case T_INT:
        *addr = value->get_int();
        break;
      case T_OBJECT:
        *addr = value->get_int(T_OBJECT);
        break;
      case T_CONFLICT:
        // A dead location. If it is an oop then we need a NULL to prevent GC from following it
        *addr = NULL_WORD;
        break;
      default:
        ShouldNotReachHere();
    }
  }

  if (is_top_frame && JvmtiExport::can_pop_frame() && thread->popframe_forcing_deopt_reexecution()) {
    // An interpreted frame was popped but it returns to a deoptimized
    // frame. The incoming arguments to the interpreted activation
    // were preserved in thread-local storage by the
    // remove_activation_preserving_args_entry in the interpreter; now
    // we put them back into the just-unpacked interpreter frame.
    // Note that this assumes that the locals arena grows toward lower
    // addresses.
    if (popframe_preserved_args_size_in_words != 0) {
      void* saved_args = thread->popframe_preserved_args();
      assert(saved_args != NULL, "must have been saved by interpreter");
#ifdef ASSERT
      assert(popframe_preserved_args_size_in_words <=
             iframe()->interpreter_frame_expression_stack_size()*Interpreter::stackElementWords,
             "expression stack size should have been extended");
#endif // ASSERT
      int top_element = iframe()->interpreter_frame_expression_stack_size()-1;
      intptr_t* base;
      if (frame::interpreter_frame_expression_stack_direction() < 0) {
        base = iframe()->interpreter_frame_expression_stack_at(top_element);
      } else {
        base = iframe()->interpreter_frame_expression_stack();
      }
      Copy::conjoint_jbytes(saved_args,
                            base,
                            popframe_preserved_args_size_in_bytes);
      thread->popframe_free_preserved_args();
    }
  }

#ifndef PRODUCT
  if (TraceDeoptimization && Verbose) {
    ttyLocker ttyl;
    tty->print_cr("[%d Interpreted Frame]", ++unpack_counter);
    iframe()->print_on(tty);
    RegisterMap map(thread);
    vframe* f = vframe::new_vframe(iframe(), &map, thread);
    f->print();

    tty->print_cr("locals size     %d", locals()->size());
    tty->print_cr("expression size %d", expressions()->size());

    method()->print_value();
    tty->cr();
    // method()->print_codes();
  } else if (TraceDeoptimization) {
    tty->print("     ");
    method()->print_value();
    Bytecodes::Code code = Bytecodes::java_code_at(method(), bcp);
    int bci = method()->bci_from(bcp);
    tty->print(" - %s", Bytecodes::name(code));
    tty->print(" @ bci %d ", bci);
    tty->print_cr("sp = " PTR_FORMAT, iframe()->sp());
  }
#endif // PRODUCT

  // The expression stack and locals are in the resource area don't leave
  // a dangling pointer in the vframeArray we leave around for debug
  // purposes

  _locals = _expressions = NULL;

}
Esempio n. 14
0
MonitorChunk::~MonitorChunk() {
  FreeHeap(monitors());
}
Esempio n. 15
0
// Save global JNI handles for any objects that this thread owns.
void javaVFrame::save_lock_entries(GrowableArray<jobject>* handle_list) {
  ResourceMark rm;

  GrowableArray<MonitorInfo*>* mons = monitors();
  if (mons->is_empty()) {
    return;  // this javaVFrame holds no monitors
  }

  HandleMark hm;
  oop wait_obj = NULL;
  {
    // save object of current wait() call (if any) for later comparison
    ObjectMonitor *mon = thread()->current_waiting_monitor();
    if (mon != NULL) {
      wait_obj = (oop)mon->object();
    }
  }
  oop pending_obj = NULL;
  {
    // save object of current enter() call (if any) for later comparison
    ObjectMonitor *mon = thread()->current_pending_monitor();
    if (mon != NULL) {
      pending_obj = (oop)mon->object();
    }
  }

  for (int i = 0; i < mons->length(); i++) {
    MonitorInfo *mi = mons->at(i);

    oop obj = mi->owner();
    if (obj == NULL) {
      // this monitor doesn't have an owning object so skip it
      continue;
    }

    if (wait_obj == obj) {
      // the thread is waiting on this monitor so it isn't really owned
      continue;
    }

    if (pending_obj == obj) {
      // the thread is pending on this monitor so it isn't really owned
      continue;
    }

    if (handle_list->length() > 0) {
      // Our list has at least one object on it so we have to check
      // for recursive object locking
      bool found = false;
      for (int j = 0; j < handle_list->length(); j++) {
        jobject jobj = handle_list->at(j);
        oop check = JNIHandles::resolve(jobj);
        if (check == obj) {
          found = true;  // we found the object
          break;
        }
      }

      if (found) {
        // already have this object so don't include it
        continue;
      }
    }

    // add the owning object to our list
    Handle hobj(obj);
    jobject jobj = (jobject)JNIHandles::make_global(hobj);
    handle_list->append(jobj);
  }
}