netty-incubator-buffer-api/src/main/java/io/netty/buffer/api/memseg/AbstractMemorySegmentManager.java
Chris Vest 95709828bf Add a ByteBuffer based implementation of Buffer
Motivation:
We need a new implementation of our new API that supports Java 11, since that is what Netty 5 will most likely baseline on.
We also need an implementation that does not rely on Unsafe.
This leaves us with ByteBuffer as the underlying currency of memory.

Modification:
- Add a NioBuffer implementation and associated supporting classes.
- The entry-point for this is a new MemoryManagers API, which is used to pick the implementation and provide the on-/off-heap MemoryManager implementations.
- Add a mechanism to configure/override which MemoryManagers implementation to use.
- The MemoryManagers implementations are service-loadable, so new ones can be discovered at runtime.
- The existing MemorySegment based implementation also get a MemoryManagers implementation.
- Expand the BufferTest to include all combinations of all implementations. We now run 360.000 tests in BufferTest.
- Some common infrastructure, like ArcDrop, is moved to its own package.
- Add a module-info.java to control the service loading, and the visibility in the various packages.
- Some pom.xml file updates to support our now module based project.

Result:
We have an implementation that should work on Java 11, but we currently don't build or test on 11.
More work needs to happen before that is a reality.
2021-03-18 15:18:22 +01:00

75 lines
2.6 KiB
Java

/*
* Copyright 2020 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:
*
* https://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.buffer.api.memseg;
import io.netty.buffer.api.AllocatorControl;
import io.netty.buffer.api.Buffer;
import io.netty.buffer.api.Drop;
import io.netty.buffer.api.MemoryManager;
import io.netty.buffer.api.memseg.MemSegBuffer.RecoverableMemory;
import jdk.incubator.foreign.MemorySegment;
import java.lang.ref.Cleaner;
import static io.netty.buffer.api.internal.Statics.convert;
public abstract class AbstractMemorySegmentManager implements MemoryManager {
@Override
public abstract boolean isNative();
@Override
public Buffer allocateConfined(AllocatorControl allocatorControl, long size, Drop<Buffer> drop, Cleaner cleaner) {
var segment = createSegment(size);
if (cleaner != null) {
segment = segment.registerCleaner(cleaner);
}
return new MemSegBuffer(segment, segment, convert(drop), allocatorControl);
}
@Override
public Buffer allocateShared(AllocatorControl allocatorControl, long size, Drop<Buffer> drop, Cleaner cleaner) {
var segment = createSegment(size).share();
if (cleaner != null) {
segment = segment.registerCleaner(cleaner);
}
return new MemSegBuffer(segment, segment, convert(drop), allocatorControl);
}
protected abstract MemorySegment createSegment(long size);
@Override
public Drop<Buffer> drop() {
return convert(MemSegBuffer.SEGMENT_CLOSE);
}
@Override
public Object unwrapRecoverableMemory(Buffer buf) {
var b = (MemSegBuffer) buf;
return b.recoverableMemory();
}
@Override
public int capacityOfRecoverableMemory(Object memory) {
return ((RecoverableMemory) memory).capacity();
}
@Override
public Buffer recoverMemory(AllocatorControl allocatorControl, Object recoverableMemory, Drop<Buffer> drop) {
var recovery = (RecoverableMemory) recoverableMemory; // TODO get rid of RecoverableMemory
return recovery.recover(convert(drop));
}
}