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
22  * or visit www.oracle.com if you need additional information or have any
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24  */
25 package jdk.internal.foreign.abi;
26 
27 import jdk.incubator.foreign.MemoryAddress;
28 import jdk.incubator.foreign.NativeSymbol;
29 import jdk.incubator.foreign.ResourceScope;
30 import jdk.internal.foreign.NativeSymbolImpl;
31 import jdk.internal.foreign.ResourceScopeImpl;
32 
33 public class UpcallStubs {
34 
35     private static void freeUpcallStub(long stubAddress) {
36         if (!freeUpcallStub0(stubAddress)) {
37             throw new IllegalStateException("Not a stub address: " + stubAddress);
38         }
39     }
40 
41     // natives
42 
43     // returns true if the stub was found (and freed)
44     private static native boolean freeUpcallStub0(long addr);
45 
46     private static native void registerNatives();
47     static {
48         registerNatives();
49     }
50 
51     static NativeSymbol makeUpcall(long entry, ResourceScope scope) {
52         ((ResourceScopeImpl)scope).addOrCleanupIfFail(new ResourceScopeImpl.ResourceList.ResourceCleanup() {
53             @Override
54             public void cleanup() {
55                 freeUpcallStub(entry);
56             }
57         });
58         return new NativeSymbolImpl("upcall:" + Long.toHexString(entry), MemoryAddress.ofLong(entry), scope);
59     }
60 }