1 /*
   2  * Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_CLASSFILE_CLASSLOADER_INLINE_HPP
  26 #define SHARE_CLASSFILE_CLASSLOADER_INLINE_HPP
  27 
  28 #include "classfile/classLoader.hpp"
  29 #include "runtime/orderAccess.hpp"
  30 
  31 // Next entry in class path
  32 inline ClassPathEntry* ClassPathEntry::next() const { return Atomic::load_acquire(&_next); }
  33 
  34 inline void ClassPathEntry::set_next(ClassPathEntry* next) {
  35   // may have unlocked readers, so ensure visibility.
  36   Atomic::release_store(&_next, next);
  37 }
  38 
  39 inline ClassPathEntry* ClassLoader::classpath_entry(int n) {
  40   assert(n >= 0, "sanity");
  41   if (n == 0) {
  42     assert(has_jrt_entry(), "No class path entry at 0 for exploded module builds");
  43     return ClassLoader::_jrt_entry;
  44   } else {
  45     // The java runtime image is always the first entry
  46     // in the FileMapInfo::_classpath_entry_table. Even though
  47     // the _jrt_entry is not included in the _first_append_entry
  48     // linked list, it must be accounted for when comparing the
  49     // class path vs. the shared archive class path.
  50     ClassPathEntry* e = ClassLoader::_first_append_entry;
  51     while (--n >= 1) {
  52       assert(e != NULL, "Not that many classpath entries.");
  53       e = e->next();
  54     }
  55     return e;
  56   }
  57 }
  58 
  59 #if INCLUDE_CDS
  60 
  61 // Helper function used by CDS code to get the number of boot classpath
  62 // entries during shared classpath setup time.
  63 
  64 inline int ClassLoader::num_boot_classpath_entries() {
  65   Arguments::assert_is_dumping_archive();
  66   assert(has_jrt_entry(), "must have a java runtime image");
  67   int num_entries = 1; // count the runtime image
  68   ClassPathEntry* e = ClassLoader::_first_append_entry;
  69   while (e != NULL) {
  70     num_entries ++;
  71     e = e->next();
  72   }
  73   return num_entries;
  74 }
  75 
  76 inline ClassPathEntry* ClassLoader::get_next_boot_classpath_entry(ClassPathEntry* e) {
  77   if (e == ClassLoader::_jrt_entry) {
  78     return ClassLoader::_first_append_entry;
  79   } else {
  80     return e->next();
  81   }
  82 }
  83 
  84 // Helper function used by CDS code to get the number of app classpath
  85 // entries during shared classpath setup time.
  86 inline int ClassLoader::num_app_classpath_entries() {
  87   Arguments::assert_is_dumping_archive();
  88   int num_entries = 0;
  89   ClassPathEntry* e= ClassLoader::_app_classpath_entries;
  90   while (e != NULL) {
  91     num_entries ++;
  92     e = e->next();
  93   }
  94   return num_entries;
  95 }
  96 
  97 #endif // INCLUDE_CDS
  98 
  99 #endif // SHARE_CLASSFILE_CLASSLOADER_INLINE_HPP