1 /*
 2  * Copyright (c) 2019, 2021, Red Hat, Inc. 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_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_INLINE_HPP
26 #define SHARE_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_INLINE_HPP
27 
28 #include "classfile/javaClasses.inline.hpp"
29 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
30 #include "gc/shenandoah/shenandoahStringDedup.hpp"
31 #include "oops/markWord.hpp"
32 
33 bool ShenandoahStringDedup::is_string_candidate(oop obj) {
34   assert(Thread::current()->is_Worker_thread(),
35         "Only from a GC worker thread");
36   return java_lang_String::is_instance(obj) &&
37          java_lang_String::value(obj) != nullptr;
38 }
39 
40 bool ShenandoahStringDedup::dedup_requested(oop obj) {
41   return java_lang_String::test_and_set_deduplication_requested(obj);
42 }
43 
44 bool ShenandoahStringDedup::is_candidate(oop obj) {
45   if (!is_string_candidate(obj)) {
46     return false;
47   }
48 
49   uint age = ShenandoahHeap::get_object_age(obj);
50   return (age <= markWord::max_age) &&
51          StringDedup::is_below_threshold_age(age) &&
52          !dedup_requested(obj);
53 }
54 
55 #endif // SHARE_GC_SHENANDOAH_SHENANDOAHSTRINGDEDUP_INLINE_HPP