--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/loaderConstraints.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,133 @@
+/*
+ * Copyright (c) 2003, 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_VM_CLASSFILE_LOADERCONSTRAINTS_HPP
+#define SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP
+
+#include "classfile/placeholders.hpp"
+#include "utilities/hashtable.hpp"
+
+class ClassLoaderData;
+class LoaderConstraintEntry;
+class Symbol;
+
+class LoaderConstraintTable : public Hashtable<InstanceKlass*, mtClass> {
+
+private:
+  LoaderConstraintEntry** find_loader_constraint(Symbol* name,
+                                                 Handle loader);
+
+public:
+
+  LoaderConstraintTable(int table_size);
+
+  LoaderConstraintEntry* new_entry(unsigned int hash, Symbol* name,
+                                   InstanceKlass* klass, int num_loaders,
+                                   int max_loaders);
+  void free_entry(LoaderConstraintEntry *entry);
+
+  LoaderConstraintEntry* bucket(int i) const {
+    return (LoaderConstraintEntry*)Hashtable<InstanceKlass*, mtClass>::bucket(i);
+  }
+
+  LoaderConstraintEntry** bucket_addr(int i) {
+    return (LoaderConstraintEntry**)Hashtable<InstanceKlass*, mtClass>::bucket_addr(i);
+  }
+
+  // Check class loader constraints
+  bool add_entry(Symbol* name, InstanceKlass* klass1, Handle loader1,
+                                    InstanceKlass* klass2, Handle loader2);
+
+  // Note:  The main entry point for this module is via SystemDictionary.
+  // SystemDictionary::check_signature_loaders(Symbol* signature,
+  //                                           Handle loader1, Handle loader2,
+  //                                           bool is_method, TRAPS)
+
+  InstanceKlass* find_constrained_klass(Symbol* name, Handle loader);
+
+  // Class loader constraints
+
+  void ensure_loader_constraint_capacity(LoaderConstraintEntry *p, int nfree);
+  void extend_loader_constraint(LoaderConstraintEntry* p, Handle loader,
+                                InstanceKlass* klass);
+  void merge_loader_constraints(LoaderConstraintEntry** pp1,
+                                LoaderConstraintEntry** pp2, InstanceKlass* klass);
+
+  bool check_or_update(InstanceKlass* k, Handle loader, Symbol* name);
+
+  void purge_loader_constraints();
+
+  void verify(PlaceholderTable* placeholders);
+  void print_on(outputStream* st) const;
+};
+
+class LoaderConstraintEntry : public HashtableEntry<InstanceKlass*, mtClass> {
+private:
+  Symbol*                _name;                   // class name
+  int                    _num_loaders;
+  int                    _max_loaders;
+  // Loader constraints enforce correct linking behavior.
+  // Thus, it really operates on ClassLoaderData which represents linking domain,
+  // not class loaders.
+  ClassLoaderData**              _loaders;                // initiating loaders
+
+public:
+
+  InstanceKlass* klass() { return literal(); }
+  InstanceKlass** klass_addr() { return literal_addr(); }
+  void set_klass(InstanceKlass* k) { set_literal(k); }
+
+  LoaderConstraintEntry* next() {
+    return (LoaderConstraintEntry*)HashtableEntry<InstanceKlass*, mtClass>::next();
+  }
+
+  LoaderConstraintEntry** next_addr() {
+    return (LoaderConstraintEntry**)HashtableEntry<InstanceKlass*, mtClass>::next_addr();
+  }
+  void set_next(LoaderConstraintEntry* next) {
+    HashtableEntry<InstanceKlass*, mtClass>::set_next(next);
+  }
+
+  Symbol* name() { return _name; }
+  void set_name(Symbol* name) {
+    _name = name;
+    if (name != NULL) name->increment_refcount();
+  }
+
+  int num_loaders() { return _num_loaders; }
+  void set_num_loaders(int i) { _num_loaders = i; }
+
+  int max_loaders() { return _max_loaders; }
+  void set_max_loaders(int i) { _max_loaders = i; }
+
+  ClassLoaderData** loaders() { return _loaders; }
+  void set_loaders(ClassLoaderData** loaders) { _loaders = loaders; }
+
+  ClassLoaderData* loader_data(int i) { return _loaders[i]; }
+  void set_loader_data(int i, ClassLoaderData* p) { _loaders[i] = p; }
+  // convenience
+  void set_loader(int i, oop p);
+};
+
+#endif // SHARE_VM_CLASSFILE_LOADERCONSTRAINTS_HPP