com.alibaba.rocketmq.shade.io.netty.util.internal.Cleaner0 Maven / Gradle / Ivy
/*
* 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 #2604.
*/
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() { }
}