src/hotspot/share/gc/z/zMarkStack.inline.hpp
changeset 50525 767cdb97f103
child 59039 c60978f87d45
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/gc/z/zMarkStack.inline.hpp	Tue Jun 12 17:40:28 2018 +0200
@@ -0,0 +1,249 @@
+/*
+ * Copyright (c) 2016, 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_ZMARKSTACK_INLINE_HPP
+#define SHARE_GC_Z_ZMARKSTACK_INLINE_HPP
+
+#include "gc/z/zMarkStack.hpp"
+#include "utilities/debug.hpp"
+#include "runtime/atomic.hpp"
+
+template <typename T, size_t S>
+inline ZStack<T, S>::ZStack() :
+    _top(0),
+    _next(NULL) {}
+
+template <typename T, size_t S>
+inline bool ZStack<T, S>::is_empty() const {
+  return _top == 0;
+}
+
+template <typename T, size_t S>
+inline bool ZStack<T, S>::is_full() const {
+  return _top == S;
+}
+
+template <typename T, size_t S>
+inline bool ZStack<T, S>::push(T value) {
+  if (is_full()) {
+    return false;
+  }
+
+  _slots[_top++] = value;
+  return true;
+}
+
+template <typename T, size_t S>
+inline bool ZStack<T, S>::pop(T& value) {
+  if (is_empty()) {
+    return false;
+  }
+
+  value = _slots[--_top];
+  return true;
+}
+
+template <typename T, size_t S>
+inline ZStack<T, S>* ZStack<T, S>::next() const {
+  return _next;
+}
+
+template <typename T, size_t S>
+inline ZStack<T, S>** ZStack<T, S>::next_addr() {
+  return &_next;
+}
+
+template <typename T>
+inline ZStackList<T>::ZStackList() :
+    _head(encode_versioned_pointer(NULL, 0)) {}
+
+template <typename T>
+inline T* ZStackList<T>::encode_versioned_pointer(const T* stack, uint32_t version) const {
+  uint64_t addr;
+
+  if (stack == NULL) {
+    addr = (uint32_t)-1;
+  } else {
+    addr = ((uint64_t)stack - ZMarkStackSpaceStart) >> ZMarkStackSizeShift;
+  }
+
+  return (T*)((addr << 32) | (uint64_t)version);
+}
+
+template <typename T>
+inline void ZStackList<T>::decode_versioned_pointer(const T* vstack, T** stack, uint32_t* version) const {
+  const uint64_t addr = (uint64_t)vstack >> 32;
+
+  if (addr == (uint32_t)-1) {
+    *stack = NULL;
+  } else {
+    *stack = (T*)((addr << ZMarkStackSizeShift) + ZMarkStackSpaceStart);
+  }
+
+  *version = (uint32_t)(uint64_t)vstack;
+}
+
+template <typename T>
+inline bool ZStackList<T>::is_empty() const {
+  const T* vstack = _head;
+  T* stack = NULL;
+  uint32_t version = 0;
+
+  decode_versioned_pointer(vstack, &stack, &version);
+  return stack == NULL;
+}
+
+template <typename T>
+inline void ZStackList<T>::push_atomic(T* stack) {
+  T* vstack = _head;
+  uint32_t version = 0;
+
+  for (;;) {
+    decode_versioned_pointer(vstack, stack->next_addr(), &version);
+    T* const new_vstack = encode_versioned_pointer(stack, version + 1);
+    T* const prev_vstack = Atomic::cmpxchg(new_vstack, &_head, vstack);
+    if (prev_vstack == vstack) {
+      // Success
+      break;
+    }
+
+    // Retry
+    vstack = prev_vstack;
+  }
+}
+
+template <typename T>
+inline T* ZStackList<T>::pop_atomic() {
+  T* vstack = _head;
+  T* stack = NULL;
+  uint32_t version = 0;
+
+  for (;;) {
+    decode_versioned_pointer(vstack, &stack, &version);
+    if (stack == NULL) {
+      return NULL;
+    }
+
+    T* const new_vstack = encode_versioned_pointer(stack->next(), version + 1);
+    T* const prev_vstack = Atomic::cmpxchg(new_vstack, &_head, vstack);
+    if (prev_vstack == vstack) {
+      // Success
+      return stack;
+    }
+
+    // Retry
+    vstack = prev_vstack;
+  }
+}
+
+inline bool ZMarkStripe::is_empty() const {
+  return _published.is_empty() && _overflowed.is_empty();
+}
+
+inline void ZMarkStripe::publish_stack(ZMarkStack* stack, bool publish) {
+  // A stack is published either on the published list or the overflowed
+  // list. The published list is used by mutators publishing stacks for GC
+  // workers to work on, while the overflowed list is used by GC workers
+  // to publish stacks that overflowed. The intention here is to avoid
+  // contention between mutators and GC workers as much as possible, while
+  // still allowing GC workers to help out and steal work from each other.
+  if (publish) {
+    _published.push_atomic(stack);
+  } else {
+    _overflowed.push_atomic(stack);
+  }
+}
+
+inline ZMarkStack* ZMarkStripe::steal_stack() {
+  // Steal overflowed stacks first, then published stacks
+  ZMarkStack* const stack = _overflowed.pop_atomic();
+  if (stack != NULL) {
+    return stack;
+  }
+
+  return _published.pop_atomic();
+}
+
+inline size_t ZMarkStripeSet::nstripes() const {
+  return _nstripes;
+}
+
+inline size_t ZMarkStripeSet::stripe_id(const ZMarkStripe* stripe) const {
+  const size_t index = ((uintptr_t)stripe - (uintptr_t)_stripes) / sizeof(ZMarkStripe);
+  assert(index < _nstripes, "Invalid index");
+  return index;
+}
+
+inline ZMarkStripe* ZMarkStripeSet::stripe_at(size_t index) {
+  assert(index < _nstripes, "Invalid index");
+  return &_stripes[index];
+}
+
+inline ZMarkStripe* ZMarkStripeSet::stripe_next(ZMarkStripe* stripe) {
+  const size_t index = (stripe_id(stripe) + 1) & _nstripes_mask;
+  assert(index < _nstripes, "Invalid index");
+  return &_stripes[index];
+}
+
+inline ZMarkStripe* ZMarkStripeSet::stripe_for_addr(uintptr_t addr) {
+  const size_t index = (addr >> ZMarkStripeShift) & _nstripes_mask;
+  assert(index < _nstripes, "Invalid index");
+  return &_stripes[index];
+}
+
+inline void ZMarkThreadLocalStacks::install(ZMarkStripeSet* stripes,
+                                            ZMarkStripe* stripe,
+                                            ZMarkStack* stack) {
+  ZMarkStack** const stackp = &_stacks[stripes->stripe_id(stripe)];
+  assert(*stackp == NULL, "Should be empty");
+  *stackp = stack;
+}
+
+inline bool ZMarkThreadLocalStacks::push(ZMarkStackAllocator* allocator,
+                                         ZMarkStripeSet* stripes,
+                                         ZMarkStripe* stripe,
+                                         ZMarkStackEntry entry,
+                                         bool publish) {
+  ZMarkStack** const stackp = &_stacks[stripes->stripe_id(stripe)];
+  ZMarkStack* const stack = *stackp;
+  if (stack != NULL && stack->push(entry)) {
+    return true;
+  }
+
+  return push_slow(allocator, stripe, stackp, entry, publish);
+}
+
+inline bool ZMarkThreadLocalStacks::pop(ZMarkStackAllocator* allocator,
+                                        ZMarkStripeSet* stripes,
+                                        ZMarkStripe* stripe,
+                                        ZMarkStackEntry& entry) {
+  ZMarkStack** const stackp = &_stacks[stripes->stripe_id(stripe)];
+  ZMarkStack* const stack = *stackp;
+  if (stack != NULL && stack->pop(entry)) {
+    return true;
+  }
+
+  return pop_slow(allocator, stripe, stackp, entry);
+}
+
+#endif // SHARE_GC_Z_ZMARKSTACK_INLINE_HPP