1 /*
 2  * Copyright (c) 2020, 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  *
21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24  */
25 package jdk.internal.foreign.abi;
26 
27 import jdk.incubator.foreign.MemoryAddress;
28 import jdk.incubator.foreign.MemorySegment;
29 import jdk.internal.foreign.ResourceScopeImpl;
30 import jdk.internal.foreign.NativeMemorySegmentImpl;
31 
32 public class UpcallStubs {
33 
34     public static MemoryAddress upcallAddress(UpcallHandler handler, ResourceScopeImpl scope) {
35         long stubAddress = handler.entryPoint();
36         return NativeMemorySegmentImpl.makeNativeSegmentUnchecked(MemoryAddress.ofLong(stubAddress), 0,
37                 () -> freeUpcallStub(stubAddress), scope).address();
38     }
39 
40     private static void freeUpcallStub(long stubAddress) {
41         if (!freeUpcallStub0(stubAddress)) {
42             throw new IllegalStateException("Not a stub address: " + stubAddress);
43         }
44     }
45 
46     // natives
47 
48     // returns true if the stub was found (and freed)
49     private static native boolean freeUpcallStub0(long addr);
50 
51     private static native void registerNatives();
52     static {
53         registerNatives();
54     }
55 }