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.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
10  *
11  * This code is distributed in the hope that it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
15  * accompanied this code).
16  *
17  * You should have received a copy of the GNU General Public License version
18  * 2 along with this work; if not, write to the Free Software Foundation,
19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20  *
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24  */
25 package jdk.internal.foreign.abi;
26 
27 import java.lang.foreign.MemorySegment;
28 import java.lang.foreign.Arena;
29 
30 import jdk.internal.foreign.MemorySessionImpl;
31 import jdk.internal.foreign.Utils;
32 
33 public final class UpcallStubs {
34 
35     private UpcallStubs() {
36     }
37 
38     private static void freeUpcallStub(long stubAddress) {
39         if (!freeUpcallStub0(stubAddress)) {
40             throw new IllegalStateException("Not a stub address: " + Utils.toHexString(stubAddress));
41         }
42     }
43 
44     // natives
45 
46     // returns true if the stub was found (and freed)
47     private static native boolean freeUpcallStub0(long addr);
48 
49     private static native void registerNatives();
50     static {
51         registerNatives();
52     }
53 
54     static MemorySegment makeUpcall(long entry, Arena arena) {
55         MemorySessionImpl.toMemorySession(arena).addOrCleanupIfFail(new MemorySessionImpl.ResourceList.ResourceCleanup() {
56             @Override
57             public void cleanup() {
58                 freeUpcallStub(entry);
59             }
60         });
61         return MemorySegment.ofAddress(entry).reinterpret(arena, null);
62     }
63 }