--- /dev/null	2018-04-03 12:55:20.301839954 +0200
+++ new/src/hotspot/share/gc/z/zBarrier.inline.hpp	2018-06-01 22:30:21.775067901 +0200
@@ -0,0 +1,300 @@
+/*
+ * Copyright (c) 2015, 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.
+ */
+
+#ifndef SHARE_GC_Z_ZBARRIER_INLINE_HPP
+#define SHARE_GC_Z_ZBARRIER_INLINE_HPP
+
+#include "gc/z/zAddress.inline.hpp"
+#include "gc/z/zBarrier.hpp"
+#include "gc/z/zOop.inline.hpp"
+#include "gc/z/zResurrection.inline.hpp"
+#include "runtime/atomic.hpp"
+
+template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
+inline oop ZBarrier::barrier(volatile oop* p, oop o) {
+  uintptr_t addr = ZOop::to_address(o);
+
+retry:
+  // Fast path
+  if (fast_path(addr)) {
+    return ZOop::to_oop(addr);
+  }
+
+  // Slow path
+  const uintptr_t good_addr = slow_path(addr);
+
+  // Self heal, but only if the address was actually updated by the slow path,
+  // which might not be the case, e.g. when marking through an already good oop.
+  if (p != NULL && good_addr != addr) {
+    const uintptr_t prev_addr = Atomic::cmpxchg(good_addr, (volatile uintptr_t*)p, addr);
+    if (prev_addr != addr) {
+      // Some other thread overwrote the oop. If this oop was updated by a
+      // weak barrier the new oop might not be good, in which case we need
+      // to re-apply this barrier.
+      addr = prev_addr;
+      goto retry;
+    }
+  }
+
+  return ZOop::to_oop(good_addr);
+}
+
+template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
+inline oop ZBarrier::weak_barrier(volatile oop* p, oop o) {
+  const uintptr_t addr = ZOop::to_address(o);
+
+  // Fast path
+  if (fast_path(addr)) {
+    // Return the good address instead of the weak good address
+    // to ensure that the currently active heap view is used.
+    return ZOop::to_oop(ZAddress::good_or_null(addr));
+  }
+
+  // Slow path
+  uintptr_t good_addr = slow_path(addr);
+
+  // Self heal unless the address returned from the slow path is null,
+  // in which case resurrection was blocked and we must let the reference
+  // processor clear the oop. Mutators are not allowed to clear oops in
+  // these cases, since that would be similar to calling Reference.clear(),
+  // which would make the reference non-discoverable or silently dropped
+  // by the reference processor.
+  if (p != NULL && good_addr != 0) {
+    // The slow path returns a good/marked address, but we never mark oops
+    // in a weak load barrier so we always self heal with the remapped address.
+    const uintptr_t weak_good_addr = ZAddress::remapped(good_addr);
+    const uintptr_t prev_addr = Atomic::cmpxchg(weak_good_addr, (volatile uintptr_t*)p, addr);
+    if (prev_addr != addr) {
+      // Some other thread overwrote the oop. The new
+      // oop is guaranteed to be weak good or null.
+      assert(ZAddress::is_weak_good_or_null(prev_addr), "Bad weak overwrite");
+
+      // Return the good address instead of the weak good address
+      // to ensure that the currently active heap view is used.
+      good_addr = ZAddress::good_or_null(prev_addr);
+    }
+  }
+
+  return ZOop::to_oop(good_addr);
+}
+
+template <ZBarrierFastPath fast_path, ZBarrierSlowPath slow_path>
+inline void ZBarrier::root_barrier(oop* p, oop o) {
+  const uintptr_t addr = ZOop::to_address(o);
+
+  // Fast path
+  if (fast_path(addr)) {
+    return;
+  }
+
+  // Slow path
+  const uintptr_t good_addr = slow_path(addr);
+
+  // Non-atomic healing helps speed up root scanning. This is safe to do
+  // since we are always healing roots in a safepoint, which means we are
+  // never racing with mutators modifying roots while we are healing them.
+  // It's also safe in case multiple GC threads try to heal the same root,
+  // since they would always heal the root in the same way and it does not
+  // matter in which order it happens.
+  *p = ZOop::to_oop(good_addr);
+}
+
+inline bool ZBarrier::is_null_fast_path(uintptr_t addr) {
+  return ZAddress::is_null(addr);
+}
+
+inline bool ZBarrier::is_good_or_null_fast_path(uintptr_t addr) {
+  return ZAddress::is_good_or_null(addr);
+}
+
+inline bool ZBarrier::is_weak_good_or_null_fast_path(uintptr_t addr) {
+  return ZAddress::is_weak_good_or_null(addr);
+}
+
+inline bool ZBarrier::is_resurrection_blocked(volatile oop* p, oop* o) {
+  const bool is_blocked = ZResurrection::is_blocked();
+
+  // Reload oop after checking the resurrection blocked state. This is
+  // done to prevent a race where we first load an oop, which is logically
+  // null but not yet cleared, then this oop is cleared by the reference
+  // processor and resurrection is unblocked. At this point the mutator
+  // would see the unblocked state and pass this invalid oop through the
+  // normal barrier path, which would incorrectly try to mark this oop.
+  if (p != NULL) {
+    // First assign to reloaded_o to avoid compiler warning about
+    // implicit dereference of volatile oop.
+    const oop reloaded_o = *p;
+    *o = reloaded_o;
+  }
+
+  return is_blocked;
+}
+
+//
+// Load barrier
+//
+inline oop ZBarrier::load_barrier_on_oop(oop o) {
+  return load_barrier_on_oop_field_preloaded((oop*)NULL, o);
+}
+
+inline oop ZBarrier::load_barrier_on_oop_field(volatile oop* p) {
+  const oop o = *p;
+  return load_barrier_on_oop_field_preloaded(p, o);
+}
+
+inline oop ZBarrier::load_barrier_on_oop_field_preloaded(volatile oop* p, oop o) {
+  return barrier<is_good_or_null_fast_path, load_barrier_on_oop_slow_path>(p, o);
+}
+
+inline void ZBarrier::load_barrier_on_oop_array(volatile oop* p, size_t length) {
+  for (volatile const oop* const end = p + length; p < end; p++) {
+    load_barrier_on_oop_field(p);
+  }
+}
+
+inline oop ZBarrier::load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o) {
+  if (is_resurrection_blocked(p, &o)) {
+    return weak_barrier<is_good_or_null_fast_path, weak_load_barrier_on_weak_oop_slow_path>(p, o);
+  }
+
+  return load_barrier_on_oop_field_preloaded(p, o);
+}
+
+inline oop ZBarrier::load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o) {
+  if (is_resurrection_blocked(p, &o)) {
+    return weak_barrier<is_good_or_null_fast_path, weak_load_barrier_on_phantom_oop_slow_path>(p, o);
+  }
+
+  return load_barrier_on_oop_field_preloaded(p, o);
+}
+
+//
+// Weak load barrier
+//
+inline oop ZBarrier::weak_load_barrier_on_oop_field_preloaded(volatile oop* p, oop o) {
+  return weak_barrier<is_weak_good_or_null_fast_path, weak_load_barrier_on_oop_slow_path>(p, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_weak_oop(oop o) {
+  return weak_load_barrier_on_weak_oop_field_preloaded((oop*)NULL, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_weak_oop_field(volatile oop* p) {
+  const oop o = *p;
+  return weak_load_barrier_on_weak_oop_field_preloaded(p, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_weak_oop_field_preloaded(volatile oop* p, oop o) {
+  if (is_resurrection_blocked(p, &o)) {
+    return weak_barrier<is_good_or_null_fast_path, weak_load_barrier_on_weak_oop_slow_path>(p, o);
+  }
+
+  return weak_load_barrier_on_oop_field_preloaded(p, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_phantom_oop(oop o) {
+  return weak_load_barrier_on_phantom_oop_field_preloaded((oop*)NULL, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_phantom_oop_field(volatile oop* p) {
+  const oop o = *p;
+  return weak_load_barrier_on_phantom_oop_field_preloaded(p, o);
+}
+
+inline oop ZBarrier::weak_load_barrier_on_phantom_oop_field_preloaded(volatile oop* p, oop o) {
+  if (is_resurrection_blocked(p, &o)) {
+    return weak_barrier<is_good_or_null_fast_path, weak_load_barrier_on_phantom_oop_slow_path>(p, o);
+  }
+
+  return weak_load_barrier_on_oop_field_preloaded(p, o);
+}
+
+//
+// Is alive barrier
+//
+inline bool ZBarrier::is_alive_barrier_on_weak_oop(oop o) {
+  // Check if oop is logically non-null. This operation
+  // is only valid when resurrection is blocked.
+  assert(ZResurrection::is_blocked(), "Invalid phase");
+  return weak_load_barrier_on_weak_oop(o) != NULL;
+}
+
+inline bool ZBarrier::is_alive_barrier_on_phantom_oop(oop o) {
+  // Check if oop is logically non-null. This operation
+  // is only valid when resurrection is blocked.
+  assert(ZResurrection::is_blocked(), "Invalid phase");
+  return weak_load_barrier_on_phantom_oop(o) != NULL;
+}
+
+//
+// Keep alive barrier
+//
+inline void ZBarrier::keep_alive_barrier_on_weak_oop_field(volatile oop* p) {
+  // This operation is only valid when resurrection is blocked.
+  assert(ZResurrection::is_blocked(), "Invalid phase");
+  const oop o = *p;
+  barrier<is_good_or_null_fast_path, keep_alive_barrier_on_weak_oop_slow_path>(p, o);
+}
+
+inline void ZBarrier::keep_alive_barrier_on_phantom_oop_field(volatile oop* p) {
+  // This operation is only valid when resurrection is blocked.
+  assert(ZResurrection::is_blocked(), "Invalid phase");
+  const oop o = *p;
+  barrier<is_good_or_null_fast_path, keep_alive_barrier_on_phantom_oop_slow_path>(p, o);
+}
+
+//
+// Mark barrier
+//
+inline void ZBarrier::mark_barrier_on_oop_field(volatile oop* p, bool finalizable) {
+  // The fast path only checks for null since the GC worker
+  // threads doing marking wants to mark through good oops.
+  const oop o = *p;
+
+  if (finalizable) {
+    barrier<is_null_fast_path, mark_barrier_on_finalizable_oop_slow_path>(p, o);
+  } else {
+    barrier<is_null_fast_path, mark_barrier_on_oop_slow_path>(p, o);
+  }
+}
+
+inline void ZBarrier::mark_barrier_on_oop_array(volatile oop* p, size_t length, bool finalizable) {
+  for (volatile const oop* const end = p + length; p < end; p++) {
+    mark_barrier_on_oop_field(p, finalizable);
+  }
+}
+
+inline void ZBarrier::mark_barrier_on_root_oop_field(oop* p) {
+  const oop o = *p;
+  root_barrier<is_good_or_null_fast_path, mark_barrier_on_root_oop_slow_path>(p, o);
+}
+
+//
+// Relocate barrier
+//
+inline void ZBarrier::relocate_barrier_on_root_oop_field(oop* p) {
+  const oop o = *p;
+  root_barrier<is_good_or_null_fast_path, relocate_barrier_on_root_oop_slow_path>(p, o);
+}
+
+#endif // SHARE_GC_Z_ZBARRIER_INLINE_HPP