1 /*
   2  * Copyright (c) 2011, 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
  23  * questions.
  24  */
  25 
  26 
  27 package sun.lwawt.macosx;
  28 
  29 /**
  30  * Safely holds and disposes of native AppKit resources, using the
  31  * correct AppKit threading and Objective-C GC semantics.
  32  */
  33 public class CFRetainedResource {
  34     private static native void nativeCFRelease(final long ptr, final boolean disposeOnAppKitThread);
  35 
  36     final boolean disposeOnAppKitThread;
  37     protected long ptr;
  38 
  39     /**
  40      * @param ptr CFRetained native object pointer
  41      * @param disposeOnAppKitThread is the object needs to be CFReleased on the main thread
  42      */
  43     protected CFRetainedResource(final long ptr, final boolean disposeOnAppKitThread) {
  44         this.disposeOnAppKitThread = disposeOnAppKitThread;
  45         this.ptr = ptr;
  46     }
  47 
  48     /**
  49      * CFReleases previous resource and assigns new pre-retained resource.
  50      * @param ptr CFRetained native object pointer
  51      */
  52     protected void setPtr(final long ptr) {
  53         synchronized (this) {
  54             if (this.ptr != 0) dispose();
  55             this.ptr = ptr;
  56         }
  57     }
  58 
  59     /**
  60      * Manually CFReleases the native resource
  61      */
  62     protected void dispose() {
  63         long oldPtr = 0L;
  64         synchronized (this) {
  65             if (ptr == 0) return;
  66             oldPtr = ptr;
  67             ptr = 0;
  68         }
  69 
  70         nativeCFRelease(oldPtr, disposeOnAppKitThread); // perform outside of the synchronized block
  71     }
  72 
  73     @Override
  74     protected void finalize() throws Throwable {
  75         dispose();
  76     }
  77 }