netty5/buffer/src/main/java/io/netty5/buffer/api/unsafe/UnsafeMemoryManager.java

99 lines
3.7 KiB
Java

/*
* Copyright 2021 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.netty5.buffer.api.unsafe;
import io.netty5.buffer.api.AllocationType;
import io.netty5.buffer.api.AllocatorControl;
import io.netty5.buffer.api.Buffer;
import io.netty5.buffer.api.Drop;
import io.netty5.buffer.api.MemoryManager;
import io.netty5.buffer.api.StandardAllocationTypes;
import io.netty5.buffer.api.internal.Statics;
import io.netty5.util.internal.PlatformDependent;
import java.lang.ref.Cleaner;
public class UnsafeMemoryManager implements MemoryManager {
public UnsafeMemoryManager() {
if (!PlatformDependent.hasUnsafe()) {
throw new UnsupportedOperationException("Unsafe is not available.");
}
if (!PlatformDependent.hasDirectBufferNoCleanerConstructor()) {
throw new UnsupportedOperationException("DirectByteBuffer internal constructor is not available.");
}
}
@Override
public Buffer allocateShared(AllocatorControl allocatorControl, long size, Drop<Buffer> drop, Cleaner cleaner,
AllocationType allocationType) {
final Object base;
final long address;
final UnsafeMemory memory;
final int size32 = Math.toIntExact(size);
if (cleaner == null) {
cleaner = Statics.CLEANER;
}
if (allocationType == StandardAllocationTypes.OFF_HEAP) {
base = null;
address = PlatformDependent.allocateMemory(size);
Statics.MEM_USAGE_NATIVE.add(size);
PlatformDependent.setMemory(address, size, (byte) 0);
memory = new UnsafeMemory(base, address, size32);
drop = new UnsafeCleanerDrop(memory, drop, cleaner);
} else if (allocationType == StandardAllocationTypes.ON_HEAP) {
base = new byte[size32];
address = PlatformDependent.byteArrayBaseOffset();
memory = new UnsafeMemory(base, address, size32);
} else {
throw new IllegalArgumentException("Unknown allocation type: " + allocationType);
}
return new UnsafeBuffer(memory, 0, size32, allocatorControl, Statics.convert(drop));
}
@Override
public Buffer allocateConstChild(Buffer readOnlyConstParent) {
assert readOnlyConstParent.readOnly();
UnsafeBuffer buf = (UnsafeBuffer) readOnlyConstParent;
return new UnsafeBuffer(buf);
}
@Override
public Drop<Buffer> drop() {
// We cannot reliably drop unsafe memory. We have to rely on the cleaner to do that.
return Statics.NO_OP_DROP;
}
@Override
public Object unwrapRecoverableMemory(Buffer buf) {
return ((UnsafeBuffer) buf).recover();
}
@Override
public Buffer recoverMemory(AllocatorControl allocatorControl, Object recoverableMemory, Drop<Buffer> drop) {
UnsafeMemory memory = (UnsafeMemory) recoverableMemory;
return new UnsafeBuffer(memory, 0, memory.size, allocatorControl, Statics.convert(drop));
}
@Override
public Object sliceMemory(Object memory, int offset, int length) {
return ((UnsafeMemory) memory).slice(offset, length);
}
@Override
public String implementationName() {
return "Unsafe";
}
}