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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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package jdk.internal.vm.compiler.libgraal;

Encapsulates a handle to an object in a libgraal isolate where the object's lifetime is bound to the lifetime of the LibGraalObject instance. At some point after a LibGraalObject is garbage collected, a call is made to release the handle, allowing the libgraal object to be collected. /**
 * Encapsulates a handle to an object in a libgraal isolate where the object's lifetime is bound to
 * the lifetime of the {@link LibGraalObject} instance. At some point after a {@link LibGraalObject}
 * is garbage collected, a call is made to release the handle, allowing the libgraal object to be
 * collected.
 */
public class LibGraalObject {

    static {
        if (LibGraal.isAvailable()) {
            LibGraal.registerNativeMethods(LibGraalObject.class);
        }
    }

    
Handle to an object in isolate. /**
     * Handle to an object in {@link #isolate}.
     */
    private final long handle;

    
The libgraal isolate containing handle. /**
     * The libgraal isolate containing {@link #handle}.
     */
    private final LibGraalIsolate isolate;

    
Creates a new LibGraalObject. 
Params:
handle – handle to an object in a libgraal isolate/**
     * Creates a new {@link LibGraalObject}.
     *
     * @param handle handle to an object in a libgraal isolate
     */
    protected LibGraalObject(long handle) {
        this.handle = handle;
        isolate = LibGraalScope.current().getIsolate();
        isolate.register(this, handle);
    }

    
Gets the raw JNI handle wrapped by this object.
@throw
IllegalArgumentException if the isolate context for the handle has destroyed./**
     * Gets the raw JNI handle wrapped by this object.
     *
     * @throw {@link IllegalArgumentException} if the isolate context for the handle has destroyed.
     */
    public long getHandle() {
        if (!isolate.isValid()) {
            throw new IllegalArgumentException(toString());
        }
        return handle;
    }

    
Releases handle in the isolate denoted by isolateThreadId. 
Returns:
false if  is not a valid handle in the isolate/**
     * Releases {@code handle} in the isolate denoted by {@code isolateThreadId}.
     *
     * @return {@code false} if {@code} is not a valid handle in the isolate
     */
    // Implementation:
    // com.oracle.svm.graal.hotspot.libgraal.LibGraalEntryPoints.releaseHandle
    static native boolean releaseHandle(long isolateThreadId, long handle);

    @Override
    public String toString() {
        String name = getClass().getSimpleName();
        Class<?> outer = getClass().getDeclaringClass();
        while (outer != null) {
            name = outer.getSimpleName() + '.' + name;
            outer = outer.getDeclaringClass();
        }
        return String.format("%s[%d]", name, handle);
    }
}