75 lines
2.6 KiB
Java
75 lines
2.6 KiB
Java
|
/*
|
||
|
|
* Copyright 2014 The Netty Project
|
||
|
|
*
|
||
|
|
* The Netty Project licenses this file to you under the Apache License,
|
||
|
|
* version 2.0 (the "License"); you may not use this file except in compliance
|
||
|
|
* with the License. You may obtain a copy of the License at:
|
||
|
|
*
|
||
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
||
|
|
*
|
||
|
|
* Unless required by applicable law or agreed to in writing, software
|
||
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
||
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
||
|
|
* License for the specific language governing permissions and limitations
|
||
|
|
* under the License.
|
||
|
|
*/
|
||
|
|
package io.netty.util.internal;
|
||
|
|
|
||
|
|
import io.netty.util.internal.logging.InternalLogger;
|
||
|
|
import io.netty.util.internal.logging.InternalLoggerFactory;
|
||
|
|
import sun.misc.Cleaner;
|
||
|
|
|
||
|
|
import java.lang.reflect.Field;
|
||
|
|
import java.nio.ByteBuffer;
|
||
|
|
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Allows to free direct {@link ByteBuffer} by using {@link Cleaner}. This is encapsulated in an extra class to be able
|
||
|
|
* to use {@link PlatformDependent0} on Android without problems.
|
||
|
|
*
|
||
|
|
* For more details see <a href="https://github.com/netty/netty/issues/2604">#2604</a>.
|
||
|
|
*/
|
||
|
|
final class Cleaner0 {
|
||
|
|
private static final long CLEANER_FIELD_OFFSET;
|
||
|
|
private static final InternalLogger logger = InternalLoggerFactory.getInstance(Cleaner0.class);
|
||
|
|
|
||
|
|
static {
|
||
|
|
ByteBuffer direct = ByteBuffer.allocateDirect(1);
|
||
|
|
Field cleanerField;
|
||
|
|
long fieldOffset = -1;
|
||
|
|
if (PlatformDependent0.hasUnsafe()) {
|
||
|
|
try {
|
||
|
|
cleanerField = direct.getClass().getDeclaredField("cleaner");
|
||
|
|
cleanerField.setAccessible(true);
|
||
|
|
Cleaner cleaner = (Cleaner) cleanerField.get(direct);
|
||
|
|
cleaner.clean();
|
||
|
|
fieldOffset = PlatformDependent0.objectFieldOffset(cleanerField);
|
||
|
|
} catch (Throwable t) {
|
||
|
|
// We don't have ByteBuffer.cleaner().
|
||
|
|
fieldOffset = -1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
logger.debug("java.nio.ByteBuffer.cleaner(): {}", fieldOffset != -1? "available" : "unavailable");
|
||
|
|
CLEANER_FIELD_OFFSET = fieldOffset;
|
||
|
|
|
||
|
|
// free buffer if possible
|
||
|
|
freeDirectBuffer(direct);
|
||
|
|
}
|
||
|
|
|
||
|
|
static void freeDirectBuffer(ByteBuffer buffer) {
|
||
|
|
if (CLEANER_FIELD_OFFSET == -1 || !buffer.isDirect()) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
try {
|
||
|
|
Cleaner cleaner = (Cleaner) PlatformDependent0.getObject(buffer, CLEANER_FIELD_OFFSET);
|
||
|
|
if (cleaner != null) {
|
||
|
|
cleaner.clean();
|
||
|
|
}
|
||
|
|
} catch (Throwable t) {
|
||
|
|
// Nothing we can do here.
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
private Cleaner0() { }
|
||
|
|
}
|