1 /*
 2  * Copyright (c) 2020, 2023, 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_CDS_CLASSLISTWRITER_HPP
26 #define SHARE_CDS_CLASSLISTWRITER_HPP
27 
28 #include "runtime/javaThread.hpp"
29 #include "runtime/mutexLocker.hpp"
30 #include "utilities/ostream.hpp"
31 
32 class ClassFileStream;
33 
34 class ClassListWriter {
35 #if INCLUDE_CDS
36   class IDTable;
37   static fileStream* _classlist_file;
38   static IDTable* _id_table;
39   static int _total_ids;
40   MutexLocker _locker;
41 
42   static int get_id(const InstanceKlass* k);
43   static bool has_id(const InstanceKlass* k);
44   static void assert_locked() { assert_lock_strong(ClassListFile_lock); }
45 public:
46   ClassListWriter() : _locker(Thread::current(), ClassListFile_lock, Mutex::_no_safepoint_check_flag) {}
47 
48   outputStream* stream() {
49     return _classlist_file;
50   }
51 
52   void handle_class_unloading(const InstanceKlass* klass);
53 
54   static bool is_enabled() {
55     return _classlist_file != nullptr && _classlist_file->is_open();
56   }
57 
58 #else
59 public:
60   static bool is_enabled() {
61     return false;
62   }
63 #endif // INCLUDE_CDS
64 
65 
66   static void init() NOT_CDS_RETURN;
67   static void write(const InstanceKlass* k, const ClassFileStream* cfs) NOT_CDS_RETURN;
68   static void write_to_stream(const InstanceKlass* k, outputStream* stream, const ClassFileStream* cfs = nullptr) NOT_CDS_RETURN;
69   static void delete_classlist() NOT_CDS_RETURN;
70 };
71 
72 #endif // SHARE_CDS_CLASSLISTWRITER_HPP