--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/classfile/sharedPathsMiscInfo.hpp	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,157 @@
+/*
+ * Copyright (c) 2014, 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_SHAREDPATHSMISCINFO_HPP
+#define SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP
+
+#include "classfile/classLoader.hpp"
+#include "runtime/os.hpp"
+
+class outputStream;
+// During dumping time, when processing class paths, we build up the dump-time
+// classpath. The JAR files that exist are stored in the list ClassLoader::_first_append_entry.
+// However, we need to store other "misc" information for run-time checking, such as
+//
+// + The values of Arguments::get_sysclasspath() used during dumping.
+//
+// + The meta-index file(s) used during dumping (incl modification time and size)
+//
+// + The class path elements specified during dumping but did not exist --
+//   these elements must also be specified at run time, and they also must not
+//   exist at run time.
+//
+// These misc items are stored in a linear buffer in SharedPathsMiscInfo.
+// The storage format is stream oriented to minimize its size.
+//
+// When writing the information to the archive file, SharedPathsMiscInfo is stored in
+// the archive file header. At run-time, this information is used only during initialization
+// (accessed using read() instead of mmap()), and is deallocated afterwards to save space.
+//
+// The SharedPathsMiscInfo class is used for both creating the the information (during
+// dumping time) and validation (at run time). Different constructors are used in the
+// two situations. See below.
+
+class SharedPathsMiscInfo : public CHeapObj<mtClass> {
+protected:
+  char* _buf_start;
+  char* _cur_ptr;
+  char* _end_ptr;
+  int   _buf_size;
+  bool  _allocated;   // was _buf_start allocated by me?
+  void ensure_size(size_t needed_bytes);
+  void add_path(const char* path, int type);
+
+  void write(const void* ptr, size_t size);
+  bool read(void* ptr, size_t size);
+
+protected:
+  static bool fail(const char* msg, const char* name = NULL);
+  virtual bool check(jint type, const char* path);
+
+public:
+  enum {
+    INITIAL_BUF_SIZE = 128
+  };
+  // This constructor is used when creating the misc information (during dump)
+  SharedPathsMiscInfo() {
+    _buf_size = INITIAL_BUF_SIZE;
+    _cur_ptr = _buf_start = NEW_C_HEAP_ARRAY(char, _buf_size, mtClass);
+    _allocated = true;
+  }
+  // This constructor is used when validating the misc info (during run time)
+  SharedPathsMiscInfo(char *buff, int size) {
+    _cur_ptr = _buf_start = buff;
+    _end_ptr = _buf_start + size;
+    _buf_size = size;
+    _allocated = false;
+  }
+  ~SharedPathsMiscInfo() {
+    if (_allocated) {
+      FREE_C_HEAP_ARRAY(char, _buf_start);
+    }
+  }
+  int get_used_bytes() {
+    return _cur_ptr - _buf_start;
+  }
+  void* buffer() {
+    return _buf_start;
+  }
+
+  // writing --
+
+  // The path must not exist at run-time
+  void add_nonexist_path(const char* path) {
+    add_path(path, NON_EXIST);
+  }
+
+  // The path must exist, and must contain exactly <num_entries> files/dirs
+  void add_boot_classpath(const char* path) {
+    add_path(path, BOOT);
+  }
+  int write_jint(jint num) {
+    write(&num, sizeof(num));
+    return 0;
+  }
+  void write_time(time_t t) {
+    write(&t, sizeof(t));
+  }
+  void write_long(long l) {
+    write(&l, sizeof(l));
+  }
+
+  bool dump_to_file(int fd) {
+    int n = get_used_bytes();
+    return (os::write(fd, _buf_start, n) == (size_t)n);
+  }
+
+  // reading --
+
+  enum {
+    BOOT      = 1,
+    NON_EXIST = 2
+  };
+
+  virtual const char* type_name(int type) {
+    switch (type) {
+    case BOOT:      return "BOOT";
+    case NON_EXIST: return "NON_EXIST";
+    default:        ShouldNotReachHere(); return "?";
+    }
+  }
+
+  virtual void print_path(outputStream* os, int type, const char* path);
+
+  bool check();
+  bool read_jint(jint *ptr) {
+    return read(ptr, sizeof(jint));
+  }
+  bool read_long(long *ptr) {
+    return read(ptr, sizeof(long));
+  }
+  bool read_time(time_t *ptr) {
+    return read(ptr, sizeof(time_t));
+  }
+};
+
+#endif // SHARE_VM_CLASSFILE_SHAREDPATHSMISCINFO_HPP