# HG changeset patch
# User kbarrett
# Date 1517262681 18000
# Node ID 3495d6050efeaa1390d9a2989252c76438adf17c
# Parent  d80d521e9cb14fc42b09aaa2b9eb40ebfffb9a9d
8194898: Move OopStorage inline definitions to an .inline.hpp
Reviewed-by: coleenp, hseigel

diff -r d80d521e9cb1 -r 3495d6050efe src/hotspot/share/gc/shared/oopStorage.cpp
--- a/src/hotspot/share/gc/shared/oopStorage.cpp	Mon Jan 29 15:11:33 2018 +0100
+++ b/src/hotspot/share/gc/shared/oopStorage.cpp	Mon Jan 29 16:51:21 2018 -0500
@@ -23,7 +23,8 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/shared/oopStorage.hpp"
+#include "gc/shared/oopStorage.inline.hpp"
+#include "gc/shared/oopStorageParState.inline.hpp"
 #include "logging/log.hpp"
 #include "memory/allocation.inline.hpp"
 #include "runtime/atomic.hpp"
diff -r d80d521e9cb1 -r 3495d6050efe src/hotspot/share/gc/shared/oopStorage.hpp
--- a/src/hotspot/share/gc/shared/oopStorage.hpp	Mon Jan 29 15:11:33 2018 +0100
+++ b/src/hotspot/share/gc/shared/oopStorage.hpp	Mon Jan 29 16:51:21 2018 -0500
@@ -26,11 +26,7 @@
 #define SHARE_GC_SHARED_OOPSTORAGE_HPP
 
 #include "memory/allocation.hpp"
-#include "metaprogramming/conditional.hpp"
-#include "metaprogramming/isConst.hpp"
 #include "oops/oop.hpp"
-#include "utilities/count_trailing_zeros.hpp"
-#include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 #include "utilities/macros.hpp"
 
@@ -131,8 +127,8 @@
   // false if any invocation of f returns false.  Otherwise, the result of
   // iteration is true.
   // precondition: at safepoint.
-  template<typename F> bool iterate_safepoint(F f);
-  template<typename F> bool iterate_safepoint(F f) const;
+  template<typename F> inline bool iterate_safepoint(F f);
+  template<typename F> inline bool iterate_safepoint(F f) const;
 
   // oops_do and weak_oops_do are wrappers around iterate_safepoint, providing
   // an adaptation layer allowing the use of existing is-alive closures and
@@ -148,12 +144,12 @@
   // invoked for p.  If is_alive->do_object_b(*p) is false, then closure will
   // not be invoked on p, and *p will be set to NULL.
 
-  template<typename Closure> void oops_do(Closure* closure);
-  template<typename Closure> void oops_do(Closure* closure) const;
-  template<typename Closure> void weak_oops_do(Closure* closure);
+  template<typename Closure> inline void oops_do(Closure* closure);
+  template<typename Closure> inline void oops_do(Closure* closure) const;
+  template<typename Closure> inline void weak_oops_do(Closure* closure);
 
   template<typename IsAliveClosure, typename Closure>
-  void weak_oops_do(IsAliveClosure* is_alive, Closure* closure);
+  inline void weak_oops_do(IsAliveClosure* is_alive, Closure* closure);
 
 #if INCLUDE_ALL_GCS
   // Parallel iteration is for the exclusive use of the GC.
@@ -181,8 +177,8 @@
   // classes. C++03 introduced access for nested classes with DR45, but xlC
   // version 12 rejects it.
 NOT_AIX( private: )
-  class Block;
-  class BlockList;
+  class Block;                  // Forward decl; defined in .inline.hpp file.
+  class BlockList;              // Forward decl for BlockEntry friend decl.
 
   class BlockEntry VALUE_OBJ_CLASS_SPEC {
     friend class BlockList;
@@ -230,62 +226,6 @@
     void unlink(const Block& block);
   };
 
-  class Block /* No base class, to avoid messing up alignment requirements */ {
-    // _data must be the first non-static data member, for alignment.
-    oop _data[BitsPerWord];
-    static const unsigned _data_pos = 0; // Position of _data.
-
-    volatile uintx _allocated_bitmask; // One bit per _data element.
-    const OopStorage* _owner;
-    void* _memory;              // Unaligned storage containing block.
-    BlockEntry _active_entry;
-    BlockEntry _allocate_entry;
-
-    Block(const OopStorage* owner, void* memory);
-    ~Block();
-
-    void check_index(unsigned index) const;
-    unsigned get_index(const oop* ptr) const;
-
-    template<typename F, typename BlockPtr>
-    static bool iterate_impl(F f, BlockPtr b);
-
-    // Noncopyable.
-    Block(const Block&);
-    Block& operator=(const Block&);
-
-  public:
-    static const BlockEntry& get_active_entry(const Block& block);
-    static const BlockEntry& get_allocate_entry(const Block& block);
-
-    static size_t allocation_size();
-    static size_t allocation_alignment_shift();
-
-    oop* get_pointer(unsigned index);
-    const oop* get_pointer(unsigned index) const;
-
-    uintx bitmask_for_index(unsigned index) const;
-    uintx bitmask_for_entry(const oop* ptr) const;
-
-    // Allocation bitmask accessors are racy.
-    bool is_full() const;
-    bool is_empty() const;
-    uintx allocated_bitmask() const;
-    uintx cmpxchg_allocated_bitmask(uintx new_value, uintx compare_value);
-
-    bool contains(const oop* ptr) const;
-
-    // Returns NULL if ptr is not in a block or not allocated in that block.
-    static Block* block_for_ptr(const OopStorage* owner, const oop* ptr);
-
-    oop* allocate();
-    static Block* new_block(const OopStorage* owner);
-    static void delete_block(const Block& block);
-
-    template<typename F> bool iterate(F f);
-    template<typename F> bool iterate(F f) const;
-  }; // class Block
-
 private:
   const char* _name;
   BlockList _active_list;
@@ -334,409 +274,6 @@
   // Wrapper for iteration handler, automatically skipping NULL entries.
   template<typename F> class SkipNullFn;
   template<typename F> static SkipNullFn<F> skip_null_fn(F f);
-
-  // Wrapper for iteration handler; ignore handler result and return true.
-  template<typename F> class AlwaysTrueFn;
-};
-
-inline OopStorage::Block* OopStorage::BlockList::head() {
-  return const_cast<Block*>(_head);
-}
-
-inline const OopStorage::Block* OopStorage::BlockList::chead() const {
-  return _head;
-}
-
-inline const OopStorage::Block* OopStorage::BlockList::ctail() const {
-  return _tail;
-}
-
-inline OopStorage::Block* OopStorage::BlockList::prev(Block& block) {
-  return const_cast<Block*>(_get_entry(block)._prev);
-}
-
-inline OopStorage::Block* OopStorage::BlockList::next(Block& block) {
-  return const_cast<Block*>(_get_entry(block)._next);
-}
-
-inline const OopStorage::Block* OopStorage::BlockList::prev(const Block& block) const {
-  return _get_entry(block)._prev;
-}
-
-inline const OopStorage::Block* OopStorage::BlockList::next(const Block& block) const {
-  return _get_entry(block)._next;
-}
-
-template<typename Closure>
-class OopStorage::OopFn VALUE_OBJ_CLASS_SPEC {
-public:
-  explicit OopFn(Closure* cl) : _cl(cl) {}
-
-  template<typename OopPtr>     // [const] oop*
-  bool operator()(OopPtr ptr) const {
-    _cl->do_oop(ptr);
-    return true;
-  }
-
-private:
-  Closure* _cl;
-};
-
-template<typename Closure>
-inline OopStorage::OopFn<Closure> OopStorage::oop_fn(Closure* cl) {
-  return OopFn<Closure>(cl);
-}
-
-template<typename IsAlive, typename F>
-class OopStorage::IfAliveFn VALUE_OBJ_CLASS_SPEC {
-public:
-  IfAliveFn(IsAlive* is_alive, F f) : _is_alive(is_alive), _f(f) {}
-
-  bool operator()(oop* ptr) const {
-    bool result = true;
-    oop v = *ptr;
-    if (v != NULL) {
-      if (_is_alive->do_object_b(v)) {
-        result = _f(ptr);
-      } else {
-        *ptr = NULL;            // Clear dead value.
-      }
-    }
-    return result;
-  }
-
-private:
-  IsAlive* _is_alive;
-  F _f;
-};
-
-template<typename IsAlive, typename F>
-inline OopStorage::IfAliveFn<IsAlive, F> OopStorage::if_alive_fn(IsAlive* is_alive, F f) {
-  return IfAliveFn<IsAlive, F>(is_alive, f);
-}
-
-template<typename F>
-class OopStorage::SkipNullFn VALUE_OBJ_CLASS_SPEC {
-public:
-  SkipNullFn(F f) : _f(f) {}
-
-  template<typename OopPtr>     // [const] oop*
-  bool operator()(OopPtr ptr) const {
-    return (*ptr != NULL) ? _f(ptr) : true;
-  }
-
-private:
-  F _f;
-};
-
-template<typename F>
-inline OopStorage::SkipNullFn<F> OopStorage::skip_null_fn(F f) {
-  return SkipNullFn<F>(f);
-}
-
-template<typename F>
-class OopStorage::AlwaysTrueFn VALUE_OBJ_CLASS_SPEC {
-  F _f;
-
-public:
-  AlwaysTrueFn(F f) : _f(f) {}
-
-  template<typename OopPtr>     // [const] oop*
-  bool operator()(OopPtr ptr) const { _f(ptr); return true; }
 };
 
-// Inline Block accesses for use in iteration inner loop.
-
-inline void OopStorage::Block::check_index(unsigned index) const {
-  assert(index < ARRAY_SIZE(_data), "Index out of bounds: %u", index);
-}
-
-inline oop* OopStorage::Block::get_pointer(unsigned index) {
-  check_index(index);
-  return &_data[index];
-}
-
-inline const oop* OopStorage::Block::get_pointer(unsigned index) const {
-  check_index(index);
-  return &_data[index];
-}
-
-inline uintx OopStorage::Block::allocated_bitmask() const {
-  return _allocated_bitmask;
-}
-
-inline uintx OopStorage::Block::bitmask_for_index(unsigned index) const {
-  check_index(index);
-  return uintx(1) << index;
-}
-
-// Provide const or non-const iteration, depending on whether BlockPtr
-// is const Block* or Block*, respectively.
-template<typename F, typename BlockPtr> // BlockPtr := [const] Block*
-inline bool OopStorage::Block::iterate_impl(F f, BlockPtr block) {
-  uintx bitmask = block->allocated_bitmask();
-  while (bitmask != 0) {
-    unsigned index = count_trailing_zeros(bitmask);
-    bitmask ^= block->bitmask_for_index(index);
-    if (!f(block->get_pointer(index))) {
-      return false;
-    }
-  }
-  return true;
-}
-
-template<typename F>
-inline bool OopStorage::Block::iterate(F f) {
-  return iterate_impl(f, this);
-}
-
-template<typename F>
-inline bool OopStorage::Block::iterate(F f) const {
-  return iterate_impl(f, this);
-}
-
-//////////////////////////////////////////////////////////////////////////////
-// Support for serial iteration, always at a safepoint.
-
-// Provide const or non-const iteration, depending on whether Storage is
-// const OopStorage* or OopStorage*, respectively.
-template<typename F, typename Storage> // Storage := [const] OopStorage
-inline bool OopStorage::iterate_impl(F f, Storage* storage) {
-  assert_at_safepoint();
-  // Propagate const/non-const iteration to the block layer, by using
-  // const or non-const blocks as corresponding to Storage.
-  typedef typename Conditional<IsConst<Storage>::value, const Block*, Block*>::type BlockPtr;
-  for (BlockPtr block = storage->_active_head;
-       block != NULL;
-       block = storage->_active_list.next(*block)) {
-    if (!block->iterate(f)) {
-      return false;
-    }
-  }
-  return true;
-}
-
-template<typename F>
-inline bool OopStorage::iterate_safepoint(F f) {
-  return iterate_impl(f, this);
-}
-
-template<typename F>
-inline bool OopStorage::iterate_safepoint(F f) const {
-  return iterate_impl(f, this);
-}
-
-template<typename Closure>
-inline void OopStorage::oops_do(Closure* cl) {
-  iterate_safepoint(oop_fn(cl));
-}
-
-template<typename Closure>
-inline void OopStorage::oops_do(Closure* cl) const {
-  iterate_safepoint(oop_fn(cl));
-}
-
-template<typename Closure>
-inline void OopStorage::weak_oops_do(Closure* cl) {
-  iterate_safepoint(skip_null_fn(oop_fn(cl)));
-}
-
-template<typename IsAliveClosure, typename Closure>
-inline void OopStorage::weak_oops_do(IsAliveClosure* is_alive, Closure* cl) {
-  iterate_safepoint(if_alive_fn(is_alive, oop_fn(cl)));
-}
-
-#if INCLUDE_ALL_GCS
-
-//////////////////////////////////////////////////////////////////////////////
-// Support for parallel and optionally concurrent state iteration.
-//
-// Parallel iteration is for the exclusive use of the GC.  Other iteration
-// clients must use serial iteration.
-//
-// Concurrent Iteration
-//
-// Iteration involves the _active_list, which contains all of the blocks owned
-// by a storage object.  This is a doubly-linked list, linked through
-// dedicated fields in the blocks.
-//
-// At most one concurrent ParState can exist at a time for a given storage
-// object.
-//
-// A concurrent ParState sets the associated storage's
-// _concurrent_iteration_active flag true when the state is constructed, and
-// sets it false when the state is destroyed.  These assignments are made with
-// _active_mutex locked.  Meanwhile, empty block deletion is not done while
-// _concurrent_iteration_active is true.  The flag check and the dependent
-// removal of a block from the _active_list is performed with _active_mutex
-// locked.  This prevents concurrent iteration and empty block deletion from
-// interfering with with each other.
-//
-// Both allocate() and delete_empty_blocks_concurrent() lock the
-// _allocate_mutex while performing their respective list manipulations,
-// preventing them from interfering with each other.
-//
-// When allocate() creates a new block, it is added to the front of the
-// _active_list.  Then _active_head is set to the new block.  When concurrent
-// iteration is started (by a parallel worker thread calling the state's
-// iterate() function), the current _active_head is used as the initial block
-// for the iteration, with iteration proceeding down the list headed by that
-// block.
-//
-// As a result, the list over which concurrent iteration operates is stable.
-// However, once the iteration is started, later allocations may add blocks to
-// the front of the list that won't be examined by the iteration.  And while
-// the list is stable, concurrent allocate() and release() operations may
-// change the set of allocated entries in a block at any time during the
-// iteration.
-//
-// As a result, a concurrent iteration handler must accept that some
-// allocations and releases that occur after the iteration started will not be
-// seen by the iteration.  Further, some may overlap examination by the
-// iteration.  To help with this, allocate() and release() have an invariant
-// that an entry's value must be NULL when it is not in use.
-//
-// An in-progress delete_empty_blocks_concurrent() operation can contend with
-// the start of a concurrent iteration over the _active_mutex.  Since both are
-// under GC control, that potential contention can be eliminated by never
-// scheduling both operations to run at the same time.
-//
-// ParState<concurrent, is_const>
-//   concurrent must be true if iteration is concurrent with the
-//   mutator, false if iteration is at a safepoint.
-//
-//   is_const must be true if the iteration is over a constant storage
-//   object, false if the iteration may modify the storage object.
-//
-// ParState([const] OopStorage* storage)
-//   Construct an object for managing an iteration over storage.  For a
-//   concurrent ParState, empty block deletion for the associated storage
-//   is inhibited for the life of the ParState.  There can be no more
-//   than one live concurrent ParState at a time for a given storage object.
-//
-// template<typename F> void iterate(F f)
-//   Repeatedly claims a block from the associated storage that has
-//   not been processed by this iteration (possibly by other threads),
-//   and applies f to each entry in the claimed block. Assume p is of
-//   type const oop* or oop*, according to is_const. Then f(p) must be
-//   a valid expression whose value is ignored.  Concurrent uses must
-//   be prepared for an entry's value to change at any time, due to
-//   mutator activity.
-//
-// template<typename Closure> void oops_do(Closure* cl)
-//   Wrapper around iterate, providing an adaptation layer allowing
-//   the use of OopClosures and similar objects for iteration.  Assume
-//   p is of type const oop* or oop*, according to is_const.  Then
-//   cl->do_oop(p) must be a valid expression whose value is ignored.
-//   Concurrent uses must be prepared for the entry's value to change
-//   at any time, due to mutator activity.
-//
-// Optional operations, provided only if !concurrent && !is_const.
-// These are not provided when is_const, because the storage object
-// may be modified by the iteration infrastructure, even if the
-// provided closure doesn't modify the storage object.  These are not
-// provided when concurrent because any pre-filtering behavior by the
-// iteration infrastructure is inappropriate for concurrent iteration;
-// modifications of the storage by the mutator could result in the
-// pre-filtering being applied (successfully or not) to objects that
-// are unrelated to what the closure finds in the entry.
-//
-// template<typename Closure> void weak_oops_do(Closure* cl)
-// template<typename IsAliveClosure, typename Closure>
-// void weak_oops_do(IsAliveClosure* is_alive, Closure* cl)
-//   Wrappers around iterate, providing an adaptation layer allowing
-//   the use of is-alive closures and OopClosures for iteration.
-//   Assume p is of type oop*.  Then
-//
-//   - cl->do_oop(p) must be a valid expression whose value is ignored.
-//
-//   - is_alive->do_object_b(*p) must be a valid expression whose value
-//   is convertible to bool.
-//
-//   If *p == NULL then neither is_alive nor cl will be invoked for p.
-//   If is_alive->do_object_b(*p) is false, then cl will not be
-//   invoked on p.
-
-class OopStorage::BasicParState VALUE_OBJ_CLASS_SPEC {
-public:
-  BasicParState(OopStorage* storage, bool concurrent);
-  ~BasicParState();
-
-  template<bool is_const, typename F> void iterate(F f) {
-    // Wrap f in ATF so we can use Block::iterate.
-    AlwaysTrueFn<F> atf_f(f);
-    ensure_iteration_started();
-    typename Conditional<is_const, const Block*, Block*>::type block;
-    while ((block = claim_next_block()) != NULL) {
-      block->iterate(atf_f);
-    }
-  }
-
-private:
-  OopStorage* _storage;
-  void* volatile _next_block;
-  bool _concurrent;
-
-  // Noncopyable.
-  BasicParState(const BasicParState&);
-  BasicParState& operator=(const BasicParState&);
-
-  void update_iteration_state(bool value);
-  void ensure_iteration_started();
-  Block* claim_next_block();
-};
-
-template<bool concurrent, bool is_const>
-class OopStorage::ParState VALUE_OBJ_CLASS_SPEC {
-  BasicParState _basic_state;
-
-public:
-  ParState(const OopStorage* storage) :
-    // For simplicity, always recorded as non-const.
-    _basic_state(const_cast<OopStorage*>(storage), concurrent)
-  {}
-
-  template<typename F>
-  void iterate(F f) {
-    _basic_state.template iterate<is_const>(f);
-  }
-
-  template<typename Closure>
-  void oops_do(Closure* cl) {
-    this->iterate(oop_fn(cl));
-  }
-};
-
-template<>
-class OopStorage::ParState<false, false> VALUE_OBJ_CLASS_SPEC {
-  BasicParState _basic_state;
-
-public:
-  ParState(OopStorage* storage) :
-    _basic_state(storage, false)
-  {}
-
-  template<typename F>
-  void iterate(F f) {
-    _basic_state.template iterate<false>(f);
-  }
-
-  template<typename Closure>
-  void oops_do(Closure* cl) {
-    this->iterate(oop_fn(cl));
-  }
-
-  template<typename Closure>
-  void weak_oops_do(Closure* cl) {
-    this->iterate(skip_null_fn(oop_fn(cl)));
-  }
-
-  template<typename IsAliveClosure, typename Closure>
-  void weak_oops_do(IsAliveClosure* is_alive, Closure* cl) {
-    this->iterate(if_alive_fn(is_alive, oop_fn(cl)));
-  }
-};
-
-#endif // INCLUDE_ALL_GCS
-
 #endif // include guard
diff -r d80d521e9cb1 -r 3495d6050efe src/hotspot/share/gc/shared/oopStorage.inline.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/oopStorage.inline.hpp	Mon Jan 29 16:51:21 2018 -0500
@@ -0,0 +1,289 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ */
+
+#ifndef SHARE_GC_SHARED_OOPSTORAGE_INLINE_HPP
+#define SHARE_GC_SHARED_OOPSTORAGE_INLINE_HPP
+
+#include "gc/shared/oopStorage.hpp"
+#include "memory/allocation.hpp"
+#include "metaprogramming/conditional.hpp"
+#include "metaprogramming/isConst.hpp"
+#include "oops/oop.hpp"
+#include "utilities/count_trailing_zeros.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class OopStorage::Block /* No base class, to avoid messing up alignment. */ {
+  // _data must be the first non-static data member, for alignment.
+  oop _data[BitsPerWord];
+  static const unsigned _data_pos = 0; // Position of _data.
+
+  volatile uintx _allocated_bitmask; // One bit per _data element.
+  const OopStorage* _owner;
+  void* _memory;              // Unaligned storage containing block.
+  BlockEntry _active_entry;
+  BlockEntry _allocate_entry;
+
+  Block(const OopStorage* owner, void* memory);
+  ~Block();
+
+  void check_index(unsigned index) const;
+  unsigned get_index(const oop* ptr) const;
+
+  template<typename F, typename BlockPtr>
+  static bool iterate_impl(F f, BlockPtr b);
+
+  // Noncopyable.
+  Block(const Block&);
+  Block& operator=(const Block&);
+
+public:
+  static const BlockEntry& get_active_entry(const Block& block);
+  static const BlockEntry& get_allocate_entry(const Block& block);
+
+  static size_t allocation_size();
+  static size_t allocation_alignment_shift();
+
+  oop* get_pointer(unsigned index);
+  const oop* get_pointer(unsigned index) const;
+
+  uintx bitmask_for_index(unsigned index) const;
+  uintx bitmask_for_entry(const oop* ptr) const;
+
+  // Allocation bitmask accessors are racy.
+  bool is_full() const;
+  bool is_empty() const;
+  uintx allocated_bitmask() const;
+  uintx cmpxchg_allocated_bitmask(uintx new_value, uintx compare_value);
+
+  bool contains(const oop* ptr) const;
+
+  // Returns NULL if ptr is not in a block or not allocated in that block.
+  static Block* block_for_ptr(const OopStorage* owner, const oop* ptr);
+
+  oop* allocate();
+  static Block* new_block(const OopStorage* owner);
+  static void delete_block(const Block& block);
+
+  template<typename F> bool iterate(F f);
+  template<typename F> bool iterate(F f) const;
+}; // class Block
+
+inline OopStorage::Block* OopStorage::BlockList::head() {
+  return const_cast<Block*>(_head);
+}
+
+inline const OopStorage::Block* OopStorage::BlockList::chead() const {
+  return _head;
+}
+
+inline const OopStorage::Block* OopStorage::BlockList::ctail() const {
+  return _tail;
+}
+
+inline OopStorage::Block* OopStorage::BlockList::prev(Block& block) {
+  return const_cast<Block*>(_get_entry(block)._prev);
+}
+
+inline OopStorage::Block* OopStorage::BlockList::next(Block& block) {
+  return const_cast<Block*>(_get_entry(block)._next);
+}
+
+inline const OopStorage::Block* OopStorage::BlockList::prev(const Block& block) const {
+  return _get_entry(block)._prev;
+}
+
+inline const OopStorage::Block* OopStorage::BlockList::next(const Block& block) const {
+  return _get_entry(block)._next;
+}
+
+template<typename Closure>
+class OopStorage::OopFn VALUE_OBJ_CLASS_SPEC {
+public:
+  explicit OopFn(Closure* cl) : _cl(cl) {}
+
+  template<typename OopPtr>     // [const] oop*
+  bool operator()(OopPtr ptr) const {
+    _cl->do_oop(ptr);
+    return true;
+  }
+
+private:
+  Closure* _cl;
+};
+
+template<typename Closure>
+inline OopStorage::OopFn<Closure> OopStorage::oop_fn(Closure* cl) {
+  return OopFn<Closure>(cl);
+}
+
+template<typename IsAlive, typename F>
+class OopStorage::IfAliveFn VALUE_OBJ_CLASS_SPEC {
+public:
+  IfAliveFn(IsAlive* is_alive, F f) : _is_alive(is_alive), _f(f) {}
+
+  bool operator()(oop* ptr) const {
+    bool result = true;
+    oop v = *ptr;
+    if (v != NULL) {
+      if (_is_alive->do_object_b(v)) {
+        result = _f(ptr);
+      } else {
+        *ptr = NULL;            // Clear dead value.
+      }
+    }
+    return result;
+  }
+
+private:
+  IsAlive* _is_alive;
+  F _f;
+};
+
+template<typename IsAlive, typename F>
+inline OopStorage::IfAliveFn<IsAlive, F> OopStorage::if_alive_fn(IsAlive* is_alive, F f) {
+  return IfAliveFn<IsAlive, F>(is_alive, f);
+}
+
+template<typename F>
+class OopStorage::SkipNullFn VALUE_OBJ_CLASS_SPEC {
+public:
+  SkipNullFn(F f) : _f(f) {}
+
+  template<typename OopPtr>     // [const] oop*
+  bool operator()(OopPtr ptr) const {
+    return (*ptr != NULL) ? _f(ptr) : true;
+  }
+
+private:
+  F _f;
+};
+
+template<typename F>
+inline OopStorage::SkipNullFn<F> OopStorage::skip_null_fn(F f) {
+  return SkipNullFn<F>(f);
+}
+
+// Inline Block accesses for use in iteration inner loop.
+
+inline void OopStorage::Block::check_index(unsigned index) const {
+  assert(index < ARRAY_SIZE(_data), "Index out of bounds: %u", index);
+}
+
+inline oop* OopStorage::Block::get_pointer(unsigned index) {
+  check_index(index);
+  return &_data[index];
+}
+
+inline const oop* OopStorage::Block::get_pointer(unsigned index) const {
+  check_index(index);
+  return &_data[index];
+}
+
+inline uintx OopStorage::Block::allocated_bitmask() const {
+  return _allocated_bitmask;
+}
+
+inline uintx OopStorage::Block::bitmask_for_index(unsigned index) const {
+  check_index(index);
+  return uintx(1) << index;
+}
+
+// Provide const or non-const iteration, depending on whether BlockPtr
+// is const Block* or Block*, respectively.
+template<typename F, typename BlockPtr> // BlockPtr := [const] Block*
+inline bool OopStorage::Block::iterate_impl(F f, BlockPtr block) {
+  uintx bitmask = block->allocated_bitmask();
+  while (bitmask != 0) {
+    unsigned index = count_trailing_zeros(bitmask);
+    bitmask ^= block->bitmask_for_index(index);
+    if (!f(block->get_pointer(index))) {
+      return false;
+    }
+  }
+  return true;
+}
+
+template<typename F>
+inline bool OopStorage::Block::iterate(F f) {
+  return iterate_impl(f, this);
+}
+
+template<typename F>
+inline bool OopStorage::Block::iterate(F f) const {
+  return iterate_impl(f, this);
+}
+
+//////////////////////////////////////////////////////////////////////////////
+// Support for serial iteration, always at a safepoint.
+
+// Provide const or non-const iteration, depending on whether Storage is
+// const OopStorage* or OopStorage*, respectively.
+template<typename F, typename Storage> // Storage := [const] OopStorage
+inline bool OopStorage::iterate_impl(F f, Storage* storage) {
+  assert_at_safepoint();
+  // Propagate const/non-const iteration to the block layer, by using
+  // const or non-const blocks as corresponding to Storage.
+  typedef typename Conditional<IsConst<Storage>::value, const Block*, Block*>::type BlockPtr;
+  for (BlockPtr block = storage->_active_head;
+       block != NULL;
+       block = storage->_active_list.next(*block)) {
+    if (!block->iterate(f)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+template<typename F>
+inline bool OopStorage::iterate_safepoint(F f) {
+  return iterate_impl(f, this);
+}
+
+template<typename F>
+inline bool OopStorage::iterate_safepoint(F f) const {
+  return iterate_impl(f, this);
+}
+
+template<typename Closure>
+inline void OopStorage::oops_do(Closure* cl) {
+  iterate_safepoint(oop_fn(cl));
+}
+
+template<typename Closure>
+inline void OopStorage::oops_do(Closure* cl) const {
+  iterate_safepoint(oop_fn(cl));
+}
+
+template<typename Closure>
+inline void OopStorage::weak_oops_do(Closure* cl) {
+  iterate_safepoint(skip_null_fn(oop_fn(cl)));
+}
+
+template<typename IsAliveClosure, typename Closure>
+inline void OopStorage::weak_oops_do(IsAliveClosure* is_alive, Closure* cl) {
+  iterate_safepoint(if_alive_fn(is_alive, oop_fn(cl)));
+}
+
+#endif // include guard
diff -r d80d521e9cb1 -r 3495d6050efe src/hotspot/share/gc/shared/oopStorageParState.inline.hpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/shared/oopStorageParState.inline.hpp	Mon Jan 29 16:51:21 2018 -0500
@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 2018, 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.
+ *
+ */
+
+#ifndef SHARE_GC_SHARED_OOPSTORAGEPARSTATE_INLINE_HPP
+#define SHARE_GC_SHARED_OOPSTORAGEPARSTATE_INLINE_HPP
+
+#include "gc/shared/oopStorage.inline.hpp"
+#include "memory/allocation.hpp"
+#include "metaprogramming/conditional.hpp"
+#include "utilities/macros.hpp"
+
+#if INCLUDE_ALL_GCS
+
+//////////////////////////////////////////////////////////////////////////////
+// Support for parallel and optionally concurrent state iteration.
+//
+// Parallel iteration is for the exclusive use of the GC.  Other iteration
+// clients must use serial iteration.
+//
+// Concurrent Iteration
+//
+// Iteration involves the _active_list, which contains all of the blocks owned
+// by a storage object.  This is a doubly-linked list, linked through
+// dedicated fields in the blocks.
+//
+// At most one concurrent ParState can exist at a time for a given storage
+// object.
+//
+// A concurrent ParState sets the associated storage's
+// _concurrent_iteration_active flag true when the state is constructed, and
+// sets it false when the state is destroyed.  These assignments are made with
+// _active_mutex locked.  Meanwhile, empty block deletion is not done while
+// _concurrent_iteration_active is true.  The flag check and the dependent
+// removal of a block from the _active_list is performed with _active_mutex
+// locked.  This prevents concurrent iteration and empty block deletion from
+// interfering with with each other.
+//
+// Both allocate() and delete_empty_blocks_concurrent() lock the
+// _allocate_mutex while performing their respective list manipulations,
+// preventing them from interfering with each other.
+//
+// When allocate() creates a new block, it is added to the front of the
+// _active_list.  Then _active_head is set to the new block.  When concurrent
+// iteration is started (by a parallel worker thread calling the state's
+// iterate() function), the current _active_head is used as the initial block
+// for the iteration, with iteration proceeding down the list headed by that
+// block.
+//
+// As a result, the list over which concurrent iteration operates is stable.
+// However, once the iteration is started, later allocations may add blocks to
+// the front of the list that won't be examined by the iteration.  And while
+// the list is stable, concurrent allocate() and release() operations may
+// change the set of allocated entries in a block at any time during the
+// iteration.
+//
+// As a result, a concurrent iteration handler must accept that some
+// allocations and releases that occur after the iteration started will not be
+// seen by the iteration.  Further, some may overlap examination by the
+// iteration.  To help with this, allocate() and release() have an invariant
+// that an entry's value must be NULL when it is not in use.
+//
+// An in-progress delete_empty_blocks_concurrent() operation can contend with
+// the start of a concurrent iteration over the _active_mutex.  Since both are
+// under GC control, that potential contention can be eliminated by never
+// scheduling both operations to run at the same time.
+//
+// ParState<concurrent, is_const>
+//   concurrent must be true if iteration is concurrent with the
+//   mutator, false if iteration is at a safepoint.
+//
+//   is_const must be true if the iteration is over a constant storage
+//   object, false if the iteration may modify the storage object.
+//
+// ParState([const] OopStorage* storage)
+//   Construct an object for managing an iteration over storage.  For a
+//   concurrent ParState, empty block deletion for the associated storage
+//   is inhibited for the life of the ParState.  There can be no more
+//   than one live concurrent ParState at a time for a given storage object.
+//
+// template<typename F> void iterate(F f)
+//   Repeatedly claims a block from the associated storage that has
+//   not been processed by this iteration (possibly by other threads),
+//   and applies f to each entry in the claimed block. Assume p is of
+//   type const oop* or oop*, according to is_const. Then f(p) must be
+//   a valid expression whose value is ignored.  Concurrent uses must
+//   be prepared for an entry's value to change at any time, due to
+//   mutator activity.
+//
+// template<typename Closure> void oops_do(Closure* cl)
+//   Wrapper around iterate, providing an adaptation layer allowing
+//   the use of OopClosures and similar objects for iteration.  Assume
+//   p is of type const oop* or oop*, according to is_const.  Then
+//   cl->do_oop(p) must be a valid expression whose value is ignored.
+//   Concurrent uses must be prepared for the entry's value to change
+//   at any time, due to mutator activity.
+//
+// Optional operations, provided only if !concurrent && !is_const.
+// These are not provided when is_const, because the storage object
+// may be modified by the iteration infrastructure, even if the
+// provided closure doesn't modify the storage object.  These are not
+// provided when concurrent because any pre-filtering behavior by the
+// iteration infrastructure is inappropriate for concurrent iteration;
+// modifications of the storage by the mutator could result in the
+// pre-filtering being applied (successfully or not) to objects that
+// are unrelated to what the closure finds in the entry.
+//
+// template<typename Closure> void weak_oops_do(Closure* cl)
+// template<typename IsAliveClosure, typename Closure>
+// void weak_oops_do(IsAliveClosure* is_alive, Closure* cl)
+//   Wrappers around iterate, providing an adaptation layer allowing
+//   the use of is-alive closures and OopClosures for iteration.
+//   Assume p is of type oop*.  Then
+//
+//   - cl->do_oop(p) must be a valid expression whose value is ignored.
+//
+//   - is_alive->do_object_b(*p) must be a valid expression whose value
+//   is convertible to bool.
+//
+//   If *p == NULL then neither is_alive nor cl will be invoked for p.
+//   If is_alive->do_object_b(*p) is false, then cl will not be
+//   invoked on p.
+
+class OopStorage::BasicParState VALUE_OBJ_CLASS_SPEC {
+  OopStorage* _storage;
+  void* volatile _next_block;
+  bool _concurrent;
+
+  // Noncopyable.
+  BasicParState(const BasicParState&);
+  BasicParState& operator=(const BasicParState&);
+
+  void update_iteration_state(bool value);
+  void ensure_iteration_started();
+  Block* claim_next_block();
+
+  // Wrapper for iteration handler; ignore handler result and return true.
+  template<typename F> class AlwaysTrueFn;
+
+public:
+  BasicParState(OopStorage* storage, bool concurrent);
+  ~BasicParState();
+
+  template<bool is_const, typename F> void iterate(F f) {
+    // Wrap f in ATF so we can use Block::iterate.
+    AlwaysTrueFn<F> atf_f(f);
+    ensure_iteration_started();
+    typename Conditional<is_const, const Block*, Block*>::type block;
+    while ((block = claim_next_block()) != NULL) {
+      block->iterate(atf_f);
+    }
+  }
+};
+
+template<typename F>
+class OopStorage::BasicParState::AlwaysTrueFn VALUE_OBJ_CLASS_SPEC {
+  F _f;
+
+public:
+  AlwaysTrueFn(F f) : _f(f) {}
+
+  template<typename OopPtr>     // [const] oop*
+  bool operator()(OopPtr ptr) const { _f(ptr); return true; }
+};
+
+template<bool concurrent, bool is_const>
+class OopStorage::ParState VALUE_OBJ_CLASS_SPEC {
+  BasicParState _basic_state;
+
+public:
+  ParState(const OopStorage* storage) :
+    // For simplicity, always recorded as non-const.
+    _basic_state(const_cast<OopStorage*>(storage), concurrent)
+  {}
+
+  template<typename F>
+  void iterate(F f) {
+    _basic_state.template iterate<is_const>(f);
+  }
+
+  template<typename Closure>
+  void oops_do(Closure* cl) {
+    this->iterate(oop_fn(cl));
+  }
+};
+
+template<>
+class OopStorage::ParState<false, false> VALUE_OBJ_CLASS_SPEC {
+  BasicParState _basic_state;
+
+public:
+  ParState(OopStorage* storage) :
+    _basic_state(storage, false)
+  {}
+
+  template<typename F>
+  void iterate(F f) {
+    _basic_state.template iterate<false>(f);
+  }
+
+  template<typename Closure>
+  void oops_do(Closure* cl) {
+    this->iterate(oop_fn(cl));
+  }
+
+  template<typename Closure>
+  void weak_oops_do(Closure* cl) {
+    this->iterate(skip_null_fn(oop_fn(cl)));
+  }
+
+  template<typename IsAliveClosure, typename Closure>
+  void weak_oops_do(IsAliveClosure* is_alive, Closure* cl) {
+    this->iterate(if_alive_fn(is_alive, oop_fn(cl)));
+  }
+};
+
+#endif // INCLUDE_ALL_GCS
+
+#endif // include guard
diff -r d80d521e9cb1 -r 3495d6050efe src/hotspot/share/runtime/jniHandles.cpp
--- a/src/hotspot/share/runtime/jniHandles.cpp	Mon Jan 29 15:11:33 2018 +0100
+++ b/src/hotspot/share/runtime/jniHandles.cpp	Mon Jan 29 16:51:21 2018 -0500
@@ -23,7 +23,7 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/shared/oopStorage.hpp"
+#include "gc/shared/oopStorage.inline.hpp"
 #include "logging/log.hpp"
 #include "memory/iterator.hpp"
 #include "oops/oop.inline.hpp"
diff -r d80d521e9cb1 -r 3495d6050efe test/hotspot/gtest/gc/shared/test_oopStorage.cpp
--- a/test/hotspot/gtest/gc/shared/test_oopStorage.cpp	Mon Jan 29 15:11:33 2018 +0100
+++ b/test/hotspot/gtest/gc/shared/test_oopStorage.cpp	Mon Jan 29 16:51:21 2018 -0500
@@ -22,7 +22,8 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/shared/oopStorage.hpp"
+#include "gc/shared/oopStorage.inline.hpp"
+#include "gc/shared/oopStorageParState.inline.hpp"
 #include "gc/shared/workgroup.hpp"
 #include "memory/allocation.inline.hpp"
 #include "memory/resourceArea.hpp"