--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc_implementation/g1/g1CodeCacheRemSet.hpp	Mon Mar 17 10:12:21 2014 +0100
@@ -0,0 +1,188 @@
+/*
+ * Copyright (c) 2014, 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_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
+#define SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/freeList.hpp"
+#include "runtime/globals.hpp"
+
+class CodeBlobClosure;
+
+class G1CodeRootChunk : public CHeapObj<mtGC> {
+ private:
+  static const int NUM_ENTRIES = 32;
+ public:
+  G1CodeRootChunk*     _next;
+  G1CodeRootChunk*     _prev;
+
+  nmethod** _top;
+
+  nmethod* _data[NUM_ENTRIES];
+
+  nmethod** bottom() const {
+    return (nmethod**) &(_data[0]);
+  }
+
+  nmethod** end() const {
+    return (nmethod**) &(_data[NUM_ENTRIES]);
+  }
+
+ public:
+  G1CodeRootChunk();
+  ~G1CodeRootChunk() {}
+
+  static size_t word_size() { return (size_t)(align_size_up_(sizeof(G1CodeRootChunk), HeapWordSize) / HeapWordSize); }
+
+  // FreeList "interface" methods
+
+  G1CodeRootChunk* next() const         { return _next; }
+  G1CodeRootChunk* prev() const         { return _prev; }
+  void set_next(G1CodeRootChunk* v)     { _next = v; assert(v != this, "Boom");}
+  void set_prev(G1CodeRootChunk* v)     { _prev = v; assert(v != this, "Boom");}
+  void clear_next()       { set_next(NULL); }
+  void clear_prev()       { set_prev(NULL); }
+
+  size_t size() const { return word_size(); }
+
+  void link_next(G1CodeRootChunk* ptr)  { set_next(ptr); }
+  void link_prev(G1CodeRootChunk* ptr)  { set_prev(ptr); }
+  void link_after(G1CodeRootChunk* ptr) {
+    link_next(ptr);
+    if (ptr != NULL) ptr->link_prev((G1CodeRootChunk*)this);
+  }
+
+  bool is_free()                 { return true; }
+
+  // New G1CodeRootChunk routines
+
+  void reset();
+
+  bool is_empty() const {
+    return _top == bottom();
+  }
+
+  bool is_full() const {
+    return _top == (nmethod**)end();
+  }
+
+  bool contains(nmethod* method) {
+    nmethod** cur = bottom();
+    while (cur != _top) {
+      if (*cur == method) return true;
+      cur++;
+    }
+    return false;
+  }
+
+  bool add(nmethod* method) {
+    if (is_full()) return false;
+    *_top = method;
+    _top++;
+    return true;
+  }
+
+  bool remove(nmethod* method) {
+    nmethod** cur = bottom();
+    while (cur != _top) {
+      if (*cur == method) {
+        memmove(cur, cur + 1, (_top - (cur + 1)) * sizeof(nmethod**));
+        _top--;
+        return true;
+      }
+      cur++;
+    }
+    return false;
+  }
+
+  void nmethods_do(CodeBlobClosure* blk);
+
+  nmethod* pop() {
+    if (is_empty()) {
+      return NULL;
+    }
+    _top--;
+    return *_top;
+  }
+};
+
+// Implements storage for a set of code roots.
+// All methods that modify the set are not thread-safe except if otherwise noted.
+class G1CodeRootSet VALUE_OBJ_CLASS_SPEC {
+ private:
+  // Global free chunk list management
+  static FreeList<G1CodeRootChunk> _free_list;
+  // Total number of chunks handed out
+  static size_t _num_chunks_handed_out;
+
+  static G1CodeRootChunk* new_chunk();
+  static void free_chunk(G1CodeRootChunk* chunk);
+  // Free all elements of the given list.
+  static void free_all_chunks(FreeList<G1CodeRootChunk>* list);
+
+  // Return the chunk that contains the given nmethod, NULL otherwise.
+  // Scans the list of chunks backwards, as this method is used to add new
+  // entries, which are typically added in bulk for a single nmethod.
+  G1CodeRootChunk* find(nmethod* method);
+  void free(G1CodeRootChunk* chunk);
+
+  size_t _length;
+  FreeList<G1CodeRootChunk> _list;
+
+ public:
+  G1CodeRootSet();
+  ~G1CodeRootSet();
+
+  static void initialize();
+  static void purge_chunks(size_t keep_ratio);
+
+  static size_t static_mem_size();
+  static size_t fl_mem_size();
+
+  // Search for the code blob from the recently allocated ones to find duplicates more quickly, as this
+  // method is likely to be repeatedly called with the same nmethod.
+  void add(nmethod* method);
+
+  void remove(nmethod* method);
+  nmethod* pop();
+
+  bool contains(nmethod* method);
+
+  void clear();
+
+  void nmethods_do(CodeBlobClosure* blk) const;
+
+  bool is_empty() { return length() == 0; }
+
+  // Length in elements
+  size_t length() const { return _length; }
+
+  // Memory size in bytes taken by this set.
+  size_t mem_size();
+
+  static void test() PRODUCT_RETURN;
+};
+
+#endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1CODECACHEREMSET_HPP