src/hotspot/share/oops/cpCache.cpp
changeset 47216 71c04702a3d5
parent 47103 a993ec29ec75
child 47634 6a0c42c40cd1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/oops/cpCache.cpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,787 @@
+/*
+ * Copyright (c) 1998, 2017, 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 "interpreter/bytecodeStream.hpp"
+#include "interpreter/bytecodes.hpp"
+#include "interpreter/interpreter.hpp"
+#include "interpreter/rewriter.hpp"
+#include "logging/log.hpp"
+#include "memory/metadataFactory.hpp"
+#include "memory/metaspaceClosure.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.inline.hpp"
+#include "oops/cpCache.hpp"
+#include "oops/objArrayOop.inline.hpp"
+#include "oops/oop.inline.hpp"
+#include "prims/methodHandles.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/handles.inline.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "utilities/macros.hpp"
+
+// Implementation of ConstantPoolCacheEntry
+
+void ConstantPoolCacheEntry::initialize_entry(int index) {
+  assert(0 < index && index < 0x10000, "sanity check");
+  _indices = index;
+  _f1 = NULL;
+  _f2 = _flags = 0;
+  assert(constant_pool_index() == index, "");
+}
+
+void ConstantPoolCacheEntry::verify_just_initialized(bool f2_used) {
+  assert((_indices & (~cp_index_mask)) == 0, "sanity");
+  assert(_f1 == NULL, "sanity");
+  assert(_flags == 0, "sanity");
+  if (!f2_used) {
+    assert(_f2 == 0, "sanity");
+  }
+}
+
+void ConstantPoolCacheEntry::reinitialize(bool f2_used) {
+  _indices &= cp_index_mask;
+  _f1 = NULL;
+  _flags = 0;
+  if (!f2_used) {
+    _f2 = 0;
+  }
+}
+
+int ConstantPoolCacheEntry::make_flags(TosState state,
+                                       int option_bits,
+                                       int field_index_or_method_params) {
+  assert(state < number_of_states, "Invalid state in make_flags");
+  int f = ((int)state << tos_state_shift) | option_bits | field_index_or_method_params;
+  // Preserve existing flag bit values
+  // The low bits are a field offset, or else the method parameter size.
+#ifdef ASSERT
+  TosState old_state = flag_state();
+  assert(old_state == (TosState)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 << bytecode_1_shift));
+}
+
+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 << bytecode_2_shift));
+}
+
+// Sets f1, ordering with previous writes.
+void ConstantPoolCacheEntry::release_set_f1(Metadata* f1) {
+  assert(f1 != NULL, "");
+  OrderAccess::release_store_ptr((HeapWord*) &_f1, f1);
+}
+
+// Sets flags, but only if the value was previously zero.
+bool ConstantPoolCacheEntry::init_flags_atomic(intptr_t flags) {
+  intptr_t result = Atomic::cmpxchg_ptr(flags, &_flags, 0);
+  return (result == 0);
+}
+
+// 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,
+                                       Klass* field_holder,
+                                       int field_index,
+                                       int field_offset,
+                                       TosState field_type,
+                                       bool is_final,
+                                       bool is_volatile,
+                                       Klass* root_klass) {
+  set_f1(field_holder);
+  set_f2(field_offset);
+  assert((field_index & field_index_mask) == field_index,
+         "field index does not fit in low flag bits");
+  set_field_flags(field_type,
+                  ((is_volatile ? 1 : 0) << is_volatile_shift) |
+                  ((is_final    ? 1 : 0) << is_final_shift),
+                  field_index);
+  set_bytecode_1(get_code);
+  set_bytecode_2(put_code);
+  NOT_PRODUCT(verify(tty));
+}
+
+void ConstantPoolCacheEntry::set_parameter_size(int value) {
+  // This routine is called only in corner cases where the CPCE is not yet initialized.
+  // See AbstractInterpreter::deopt_continue_after_entry.
+  assert(_flags == 0 || parameter_size() == 0 || parameter_size() == value,
+         "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
+  // Setting the parameter size by itself is only safe if the
+  // current value of _flags is 0, otherwise another thread may have
+  // updated it and we don't want to overwrite that value.  Don't
+  // bother trying to update it once it's nonzero but always make
+  // sure that the final parameter size agrees with what was passed.
+  if (_flags == 0) {
+    Atomic::cmpxchg_ptr((value & parameter_size_mask), &_flags, 0);
+  }
+  guarantee(parameter_size() == value,
+            "size must not change: parameter_size=%d, value=%d", parameter_size(), value);
+}
+
+void ConstantPoolCacheEntry::set_direct_or_vtable_call(Bytecodes::Code invoke_code,
+                                                       const methodHandle& method,
+                                                       int vtable_index,
+                                                       bool sender_is_interface) {
+  bool is_vtable_call = (vtable_index >= 0);  // FIXME: split this method on this boolean
+  assert(method->interpreter_entry() != NULL, "should have been set at this point");
+  assert(!method->is_obsolete(),  "attempt to write obsolete method to cpCache");
+
+  int byte_no = -1;
+  bool change_to_virtual = false;
+
+  switch (invoke_code) {
+    case Bytecodes::_invokeinterface:
+      // We get here from InterpreterRuntime::resolve_invoke when an invokeinterface
+      // instruction somehow links to a non-interface method (in Object).
+      // In that case, the method has no itable index and must be invoked as a virtual.
+      // Set a flag to keep track of this corner case.
+      change_to_virtual = true;
+
+      // ...and fall through as if we were handling invokevirtual:
+    case Bytecodes::_invokevirtual:
+      {
+        if (!is_vtable_call) {
+          assert(method->can_be_statically_bound(), "");
+          // set_f2_as_vfinal_method checks if is_vfinal flag is true.
+          set_method_flags(as_TosState(method->result_type()),
+                           (                             1      << is_vfinal_shift) |
+                           ((method->is_final_method() ? 1 : 0) << is_final_shift)  |
+                           ((change_to_virtual         ? 1 : 0) << is_forced_virtual_shift),
+                           method()->size_of_parameters());
+          set_f2_as_vfinal_method(method());
+        } else {
+          assert(!method->can_be_statically_bound(), "");
+          assert(vtable_index >= 0, "valid index");
+          assert(!method->is_final_method(), "sanity");
+          set_method_flags(as_TosState(method->result_type()),
+                           ((change_to_virtual ? 1 : 0) << is_forced_virtual_shift),
+                           method()->size_of_parameters());
+          set_f2(vtable_index);
+        }
+        byte_no = 2;
+        break;
+      }
+
+    case Bytecodes::_invokespecial:
+    case Bytecodes::_invokestatic:
+      assert(!is_vtable_call, "");
+      // Note:  Read and preserve the value of the is_vfinal flag on any
+      // invokevirtual bytecode shared with this constant pool cache entry.
+      // It is cheap and safe to consult is_vfinal() at all times.
+      // Once is_vfinal is set, it must stay that way, lest we get a dangling oop.
+      set_method_flags(as_TosState(method->result_type()),
+                       ((is_vfinal()               ? 1 : 0) << is_vfinal_shift) |
+                       ((method->is_final_method() ? 1 : 0) << is_final_shift),
+                       method()->size_of_parameters());
+      set_f1(method());
+      byte_no = 1;
+      break;
+    default:
+      ShouldNotReachHere();
+      break;
+  }
+
+  // Note:  byte_no also appears in TemplateTable::resolve.
+  if (byte_no == 1) {
+    assert(invoke_code != Bytecodes::_invokevirtual &&
+           invoke_code != Bytecodes::_invokeinterface, "");
+    // Don't mark invokespecial to method as resolved if sender is an interface.  The receiver
+    // has to be checked that it is a subclass of the current class every time this bytecode
+    // is executed.
+    if (invoke_code != Bytecodes::_invokespecial || !sender_is_interface ||
+        method->name() == vmSymbols::object_initializer_name()) {
+    set_bytecode_1(invoke_code);
+    }
+  } else if (byte_no == 2)  {
+    if (change_to_virtual) {
+      assert(invoke_code == Bytecodes::_invokeinterface, "");
+      // 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);
+    } else {
+      assert(invoke_code == Bytecodes::_invokevirtual, "");
+    }
+    // set up for invokevirtual, even if linking for invokeinterface also:
+    set_bytecode_2(Bytecodes::_invokevirtual);
+  } else {
+    ShouldNotReachHere();
+  }
+  NOT_PRODUCT(verify(tty));
+}
+
+void ConstantPoolCacheEntry::set_direct_call(Bytecodes::Code invoke_code, const methodHandle& method,
+                                             bool sender_is_interface) {
+  int index = Method::nonvirtual_vtable_index;
+  // index < 0; FIXME: inline and customize set_direct_or_vtable_call
+  set_direct_or_vtable_call(invoke_code, method, index, sender_is_interface);
+}
+
+void ConstantPoolCacheEntry::set_vtable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
+  // either the method is a miranda or its holder should accept the given index
+  assert(method->method_holder()->is_interface() || method->method_holder()->verify_vtable_index(index), "");
+  // index >= 0; FIXME: inline and customize set_direct_or_vtable_call
+  set_direct_or_vtable_call(invoke_code, method, index, false);
+}
+
+void ConstantPoolCacheEntry::set_itable_call(Bytecodes::Code invoke_code, const methodHandle& method, int index) {
+  assert(method->method_holder()->verify_itable_index(index), "");
+  assert(invoke_code == Bytecodes::_invokeinterface, "");
+  InstanceKlass* interf = method->method_holder();
+  assert(interf->is_interface(), "must be an interface");
+  assert(!method->is_final_method(), "interfaces do not have final methods; cannot link to one here");
+  set_f1(interf);
+  set_f2(index);
+  set_method_flags(as_TosState(method->result_type()),
+                   0,  // no option bits
+                   method()->size_of_parameters());
+  set_bytecode_1(Bytecodes::_invokeinterface);
+}
+
+
+void ConstantPoolCacheEntry::set_method_handle(const constantPoolHandle& cpool, const CallInfo &call_info) {
+  set_method_handle_common(cpool, Bytecodes::_invokehandle, call_info);
+}
+
+void ConstantPoolCacheEntry::set_dynamic_call(const constantPoolHandle& cpool, const CallInfo &call_info) {
+  set_method_handle_common(cpool, Bytecodes::_invokedynamic, call_info);
+}
+
+void ConstantPoolCacheEntry::set_method_handle_common(const constantPoolHandle& cpool,
+                                                      Bytecodes::Code invoke_code,
+                                                      const CallInfo &call_info) {
+  // NOTE: This CPCE can be the subject of data races.
+  // There are three words to update: flags, refs[f2], f1 (in that order).
+  // Writers must store all other values before f1.
+  // Readers must test f1 first for non-null before reading other fields.
+  // Competing writers must acquire exclusive access via a lock.
+  // A losing writer waits on the lock until the winner writes f1 and leaves
+  // the lock, so that when the losing writer returns, he can use the linked
+  // cache entry.
+
+  objArrayHandle resolved_references(Thread::current(), cpool->resolved_references());
+  // Use the resolved_references() lock for this cpCache entry.
+  // resolved_references are created for all classes with Invokedynamic, MethodHandle
+  // or MethodType constant pool cache entries.
+  assert(resolved_references() != NULL,
+         "a resolved_references array should have been created for this class");
+  ObjectLocker ol(resolved_references, Thread::current());
+  if (!is_f1_null()) {
+    return;
+  }
+
+  const methodHandle adapter = call_info.resolved_method();
+  const Handle appendix      = call_info.resolved_appendix();
+  const Handle method_type   = call_info.resolved_method_type();
+  const bool has_appendix    = appendix.not_null();
+  const bool has_method_type = method_type.not_null();
+
+  // Write the flags.
+  set_method_flags(as_TosState(adapter->result_type()),
+                   ((has_appendix    ? 1 : 0) << has_appendix_shift   ) |
+                   ((has_method_type ? 1 : 0) << has_method_type_shift) |
+                   (                   1      << is_final_shift       ),
+                   adapter->size_of_parameters());
+
+  if (TraceInvokeDynamic) {
+    ttyLocker ttyl;
+    tty->print_cr("set_method_handle bc=%d appendix=" PTR_FORMAT "%s method_type=" PTR_FORMAT "%s method=" PTR_FORMAT " ",
+                  invoke_code,
+                  p2i(appendix()),    (has_appendix    ? "" : " (unused)"),
+                  p2i(method_type()), (has_method_type ? "" : " (unused)"),
+                  p2i(adapter()));
+    adapter->print();
+    if (has_appendix)  appendix()->print();
+  }
+
+  // Method handle invokes and invokedynamic sites use both cp cache words.
+  // refs[f2], if not null, contains a value passed as a trailing argument to the adapter.
+  // In the general case, this could be the call site's MethodType,
+  // for use with java.lang.Invokers.checkExactType, or else a CallSite object.
+  // f1 contains the adapter method which manages the actual call.
+  // In the general case, this is a compiled LambdaForm.
+  // (The Java code is free to optimize these calls by binding other
+  // sorts of methods and appendices to call sites.)
+  // JVM-level linking is via f1, as if for invokespecial, and signatures are erased.
+  // The appendix argument (if any) is added to the signature, and is counted in the parameter_size bits.
+  // Even with the appendix, the method will never take more than 255 parameter slots.
+  //
+  // This means that given a call site like (List)mh.invoke("foo"),
+  // the f1 method has signature '(Ljl/Object;Ljl/invoke/MethodType;)Ljl/Object;',
+  // not '(Ljava/lang/String;)Ljava/util/List;'.
+  // The fact that String and List are involved is encoded in the MethodType in refs[f2].
+  // This allows us to create fewer Methods, while keeping type safety.
+  //
+
+  // Store appendix, if any.
+  if (has_appendix) {
+    const int appendix_index = f2_as_index() + _indy_resolved_references_appendix_offset;
+    assert(appendix_index >= 0 && appendix_index < resolved_references->length(), "oob");
+    assert(resolved_references->obj_at(appendix_index) == NULL, "init just once");
+    resolved_references->obj_at_put(appendix_index, appendix());
+  }
+
+  // Store MethodType, if any.
+  if (has_method_type) {
+    const int method_type_index = f2_as_index() + _indy_resolved_references_method_type_offset;
+    assert(method_type_index >= 0 && method_type_index < resolved_references->length(), "oob");
+    assert(resolved_references->obj_at(method_type_index) == NULL, "init just once");
+    resolved_references->obj_at_put(method_type_index, method_type());
+  }
+
+  release_set_f1(adapter());  // This must be the last one to set (see NOTE above)!
+
+  // The interpreter assembly code does not check byte_2,
+  // but it is used by is_resolved, method_if_resolved, etc.
+  set_bytecode_1(invoke_code);
+  NOT_PRODUCT(verify(tty));
+  if (TraceInvokeDynamic) {
+    ttyLocker ttyl;
+    this->print(tty, 0);
+  }
+}
+
+Method* ConstantPoolCacheEntry::method_if_resolved(const constantPoolHandle& cpool) {
+  // Decode the action of set_method and set_interface_call
+  Bytecodes::Code invoke_code = bytecode_1();
+  if (invoke_code != (Bytecodes::Code)0) {
+    Metadata* f1 = f1_ord();
+    if (f1 != NULL) {
+      switch (invoke_code) {
+      case Bytecodes::_invokeinterface:
+        assert(f1->is_klass(), "");
+        return klassItable::method_for_itable_index((Klass*)f1, f2_as_index());
+      case Bytecodes::_invokestatic:
+      case Bytecodes::_invokespecial:
+        assert(!has_appendix(), "");
+      case Bytecodes::_invokehandle:
+      case Bytecodes::_invokedynamic:
+        assert(f1->is_method(), "");
+        return (Method*)f1;
+      default:
+        break;
+      }
+    }
+  }
+  invoke_code = bytecode_2();
+  if (invoke_code != (Bytecodes::Code)0) {
+    switch (invoke_code) {
+    case Bytecodes::_invokevirtual:
+      if (is_vfinal()) {
+        // invokevirtual
+        Method* m = f2_as_vfinal_method();
+        assert(m->is_method(), "");
+        return m;
+      } else {
+        int holder_index = cpool->uncached_klass_ref_index_at(constant_pool_index());
+        if (cpool->tag_at(holder_index).is_klass()) {
+          Klass* klass = cpool->resolved_klass_at(holder_index);
+          return klass->method_at_vtable(f2_as_index());
+        }
+      }
+      break;
+    default:
+      break;
+    }
+  }
+  return NULL;
+}
+
+
+oop ConstantPoolCacheEntry::appendix_if_resolved(const constantPoolHandle& cpool) {
+  if (!has_appendix())
+    return NULL;
+  const int ref_index = f2_as_index() + _indy_resolved_references_appendix_offset;
+  objArrayOop resolved_references = cpool->resolved_references();
+  return resolved_references->obj_at(ref_index);
+}
+
+
+oop ConstantPoolCacheEntry::method_type_if_resolved(const constantPoolHandle& cpool) {
+  if (!has_method_type())
+    return NULL;
+  const int ref_index = f2_as_index() + _indy_resolved_references_method_type_offset;
+  objArrayOop resolved_references = cpool->resolved_references();
+  return resolved_references->obj_at(ref_index);
+}
+
+
+#if INCLUDE_JVMTI
+// RedefineClasses() API support:
+// If this ConstantPoolCacheEntry refers to old_method then update it
+// to refer to new_method.
+bool ConstantPoolCacheEntry::adjust_method_entry(Method* old_method,
+       Method* new_method, bool * trace_name_printed) {
+
+  if (is_vfinal()) {
+    // virtual and final so _f2 contains method ptr instead of vtable index
+    if (f2_as_vfinal_method() == old_method) {
+      // match old_method so need an update
+      // NOTE: can't use set_f2_as_vfinal_method as it asserts on different values
+      _f2 = (intptr_t)new_method;
+      if (log_is_enabled(Info, redefine, class, update)) {
+        ResourceMark rm;
+        if (!(*trace_name_printed)) {
+          log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
+          *trace_name_printed = true;
+        }
+        log_debug(redefine, class, update, constantpool)
+          ("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 (_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 (_f1 == old_method) {
+    _f1 = new_method;
+    if (log_is_enabled(Info, redefine, class, update)) {
+      ResourceMark rm;
+      if (!(*trace_name_printed)) {
+        log_info(redefine, class, update)("adjust: name=%s", old_method->method_holder()->external_name());
+        *trace_name_printed = true;
+      }
+      log_debug(redefine, class, update, constantpool)
+        ("cpc entry update: %s(%s)", new_method->name()->as_C_string(), new_method->signature()->as_C_string());
+    }
+    return true;
+  }
+
+  return false;
+}
+
+// a constant pool cache entry should never contain old or obsolete methods
+bool ConstantPoolCacheEntry::check_no_old_or_obsolete_entries() {
+  if (is_vfinal()) {
+    // virtual and final so _f2 contains method ptr instead of vtable index
+    Metadata* f2 = (Metadata*)_f2;
+    // Return false if _f2 refers to an old or an obsolete method.
+    // _f2 == NULL || !_f2->is_method() are just as unexpected here.
+    return (f2 != NULL NOT_PRODUCT(&& f2->is_valid()) && f2->is_method() &&
+            !((Method*)f2)->is_old() && !((Method*)f2)->is_obsolete());
+  } else if (_f1 == NULL ||
+             (NOT_PRODUCT(_f1->is_valid() &&) !_f1->is_method())) {
+    // _f1 == NULL || !_f1->is_method() are OK here
+    return true;
+  }
+  // return false if _f1 refers to a non-deleted old or obsolete method
+  return (NOT_PRODUCT(_f1->is_valid() &&) _f1->is_method() &&
+          (f1_as_method()->is_deleted() ||
+          (!f1_as_method()->is_old() && !f1_as_method()->is_obsolete())));
+}
+
+Method* ConstantPoolCacheEntry::get_interesting_method_entry(Klass* k) {
+  if (!is_method_entry()) {
+    // not a method entry so not interesting by default
+    return NULL;
+  }
+  Method* m = NULL;
+  if (is_vfinal()) {
+    // virtual and final so _f2 contains method ptr instead of vtable index
+    m = f2_as_vfinal_method();
+  } else if (is_f1_null()) {
+    // NULL _f1 means this is a virtual entry so also not interesting
+    return NULL;
+  } else {
+    if (!(_f1->is_method())) {
+      // _f1 can also contain a Klass* for an interface
+      return NULL;
+    }
+    m = f1_as_method();
+  }
+  assert(m != NULL && m->is_method(), "sanity check");
+  if (m == NULL || !m->is_method() || (k != NULL && m->method_holder() != k)) {
+    // robustness for above sanity checks or method is not in
+    // the interesting class
+    return NULL;
+  }
+  // the method is in the interesting class so the entry is interesting
+  return m;
+}
+#endif // INCLUDE_JVMTI
+
+void ConstantPoolCacheEntry::print(outputStream* st, int index) const {
+  // print separator
+  if (index == 0) st->print_cr("                 -------------");
+  // print entry
+  st->print("%3d  (" PTR_FORMAT ")  ", index, (intptr_t)this);
+  st->print_cr("[%02x|%02x|%5d]", bytecode_2(), bytecode_1(),
+               constant_pool_index());
+  st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f1);
+  st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_f2);
+  st->print_cr("                 [   " PTR_FORMAT "]", (intptr_t)_flags);
+  st->print_cr("                 -------------");
+}
+
+void ConstantPoolCacheEntry::verify(outputStream* st) const {
+  // not implemented yet
+}
+
+// Implementation of ConstantPoolCache
+
+ConstantPoolCache* ConstantPoolCache::allocate(ClassLoaderData* loader_data,
+                                     const intStack& index_map,
+                                     const intStack& invokedynamic_index_map,
+                                     const intStack& invokedynamic_map, TRAPS) {
+
+  const int length = index_map.length() + invokedynamic_index_map.length();
+  int size = ConstantPoolCache::size(length);
+
+  return new (loader_data, size, MetaspaceObj::ConstantPoolCacheType, THREAD)
+    ConstantPoolCache(length, index_map, invokedynamic_index_map, invokedynamic_map);
+}
+
+void ConstantPoolCache::initialize(const intArray& inverse_index_map,
+                                   const intArray& invokedynamic_inverse_index_map,
+                                   const intArray& invokedynamic_references_map) {
+  for (int i = 0; i < inverse_index_map.length(); i++) {
+    ConstantPoolCacheEntry* e = entry_at(i);
+    int original_index = inverse_index_map.at(i);
+    e->initialize_entry(original_index);
+    assert(entry_at(i) == e, "sanity");
+  }
+
+  // Append invokedynamic entries at the end
+  int invokedynamic_offset = inverse_index_map.length();
+  for (int i = 0; i < invokedynamic_inverse_index_map.length(); i++) {
+    int offset = i + invokedynamic_offset;
+    ConstantPoolCacheEntry* e = entry_at(offset);
+    int original_index = invokedynamic_inverse_index_map.at(i);
+    e->initialize_entry(original_index);
+    assert(entry_at(offset) == e, "sanity");
+  }
+
+  for (int ref = 0; ref < invokedynamic_references_map.length(); ref++) {
+    const int cpci = invokedynamic_references_map.at(ref);
+    if (cpci >= 0) {
+#ifdef ASSERT
+      // invokedynamic and invokehandle have more entries; check if they
+      // all point to the same constant pool cache entry.
+      for (int entry = 1; entry < ConstantPoolCacheEntry::_indy_resolved_references_entries; entry++) {
+        const int cpci_next = invokedynamic_references_map.at(ref + entry);
+        assert(cpci == cpci_next, "%d == %d", cpci, cpci_next);
+      }
+#endif
+      entry_at(cpci)->initialize_resolved_reference_index(ref);
+      ref += ConstantPoolCacheEntry::_indy_resolved_references_entries - 1;  // skip extra entries
+    }
+  }
+}
+
+void ConstantPoolCache::verify_just_initialized() {
+  DEBUG_ONLY(walk_entries_for_initialization(/*check_only = */ true));
+}
+
+void ConstantPoolCache::remove_unshareable_info() {
+  walk_entries_for_initialization(/*check_only = */ false);
+}
+
+void ConstantPoolCache::walk_entries_for_initialization(bool check_only) {
+  assert(DumpSharedSpaces, "sanity");
+  // When dumping the archive, we want to clean up the ConstantPoolCache
+  // to remove any effect of linking due to the execution of Java code --
+  // each ConstantPoolCacheEntry will have the same contents as if
+  // ConstantPoolCache::initialize has just returned:
+  //
+  // - We keep the ConstantPoolCache::constant_pool_index() bits for all entries.
+  // - We keep the "f2" field for entries used by invokedynamic and invokehandle
+  // - All other bits in the entries are cleared to zero.
+  ResourceMark rm;
+
+  InstanceKlass* ik = constant_pool()->pool_holder();
+  bool* f2_used = NEW_RESOURCE_ARRAY(bool, length());
+  memset(f2_used, 0, sizeof(bool) * length());
+
+  // Find all the slots that we need to preserve f2
+  for (int i = 0; i < ik->methods()->length(); i++) {
+    Method* m = ik->methods()->at(i);
+    RawBytecodeStream bcs(m);
+    while (!bcs.is_last_bytecode()) {
+      Bytecodes::Code opcode = bcs.raw_next();
+      switch (opcode) {
+      case Bytecodes::_invokedynamic: {
+          int index = Bytes::get_native_u4(bcs.bcp() + 1);
+          int cp_cache_index = constant_pool()->invokedynamic_cp_cache_index(index);
+          f2_used[cp_cache_index] = 1;
+        }
+        break;
+      case Bytecodes::_invokehandle: {
+          int cp_cache_index = Bytes::get_native_u2(bcs.bcp() + 1);
+          f2_used[cp_cache_index] = 1;
+        }
+        break;
+      default:
+        break;
+      }
+    }
+  }
+
+  if (check_only) {
+    DEBUG_ONLY(
+      for (int i=0; i<length(); i++) {
+        entry_at(i)->verify_just_initialized(f2_used[i]);
+      })
+  } else {
+    for (int i=0; i<length(); i++) {
+      entry_at(i)->reinitialize(f2_used[i]);
+    }
+  }
+}
+
+void ConstantPoolCache::deallocate_contents(ClassLoaderData* data) {
+  assert(!is_shared(), "shared caches are not deallocated");
+  data->remove_handle(_resolved_references);
+  set_resolved_references(NULL);
+  MetadataFactory::free_array<u2>(data, _reference_map);
+  set_reference_map(NULL);
+}
+
+#if INCLUDE_CDS_JAVA_HEAP
+oop ConstantPoolCache::archived_references() {
+  assert(UseSharedSpaces, "UseSharedSpaces expected.");
+  return oopDesc::decode_heap_oop(_archived_references);
+}
+
+void ConstantPoolCache::set_archived_references(oop o) {
+  assert(DumpSharedSpaces, "called only during runtime");
+  _archived_references = oopDesc::encode_heap_oop(o);
+}
+#endif
+
+#if INCLUDE_JVMTI
+// RedefineClasses() API support:
+// If any entry of this ConstantPoolCache points to any of
+// old_methods, replace it with the corresponding new_method.
+void ConstantPoolCache::adjust_method_entries(InstanceKlass* holder, bool * trace_name_printed) {
+  for (int i = 0; i < length(); i++) {
+    ConstantPoolCacheEntry* entry = entry_at(i);
+    Method* old_method = entry->get_interesting_method_entry(holder);
+    if (old_method == NULL || !old_method->is_old()) {
+      continue; // skip uninteresting entries
+    }
+    if (old_method->is_deleted()) {
+      // clean up entries with deleted methods
+      entry->initialize_entry(entry->constant_pool_index());
+      continue;
+    }
+    Method* new_method = holder->method_with_idnum(old_method->orig_method_idnum());
+
+    assert(new_method != NULL, "method_with_idnum() should not be NULL");
+    assert(old_method != new_method, "sanity check");
+
+    entry_at(i)->adjust_method_entry(old_method, new_method, trace_name_printed);
+  }
+}
+
+// the constant pool cache should never contain old or obsolete methods
+bool ConstantPoolCache::check_no_old_or_obsolete_entries() {
+  for (int i = 1; i < length(); i++) {
+    if (entry_at(i)->get_interesting_method_entry(NULL) != NULL &&
+        !entry_at(i)->check_no_old_or_obsolete_entries()) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void ConstantPoolCache::dump_cache() {
+  for (int i = 1; i < length(); i++) {
+    if (entry_at(i)->get_interesting_method_entry(NULL) != NULL) {
+      entry_at(i)->print(tty, i);
+    }
+  }
+}
+#endif // INCLUDE_JVMTI
+
+void ConstantPoolCache::metaspace_pointers_do(MetaspaceClosure* it) {
+  log_trace(cds)("Iter(ConstantPoolCache): %p", this);
+  it->push(&_constant_pool);
+  it->push(&_reference_map);
+}
+
+// Printing
+
+void ConstantPoolCache::print_on(outputStream* st) const {
+  assert(is_constantPoolCache(), "obj must be constant pool cache");
+  st->print_cr("%s", internal_name());
+  // print constant pool cache entries
+  for (int i = 0; i < length(); i++) entry_at(i)->print(st, i);
+}
+
+void ConstantPoolCache::print_value_on(outputStream* st) const {
+  assert(is_constantPoolCache(), "obj must be constant pool cache");
+  st->print("cache [%d]", length());
+  print_address_on(st);
+  st->print(" for ");
+  constant_pool()->print_value_on(st);
+}
+
+
+// Verification
+
+void ConstantPoolCache::verify_on(outputStream* st) {
+  guarantee(is_constantPoolCache(), "obj must be constant pool cache");
+  // print constant pool cache entries
+  for (int i = 0; i < length(); i++) entry_at(i)->verify(st);
+}