org.asynchttpclient.shaded.io.netty.channel.kqueue.KQueueEventArray Maven / Gradle / Ivy
/*
* Copyright 2016 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 org.asynchttpclient.shaded.io.netty.channel.kqueue;
import org.asynchttpclient.shaded.io.netty.channel.unix.Buffer;
import org.asynchttpclient.shaded.io.netty.util.internal.PlatformDependent;
import java.nio.ByteBuffer;
/**
* Represents an array of kevent structures, backed by offheap memory.
*
* struct kevent {
* uintptr_t ident;
* short keventFilter;
* u_short flags;
* u_int fflags;
* intptr_t data;
* void *udata;
* };
*/
final class KQueueEventArray {
private static final int KQUEUE_EVENT_SIZE = Native.sizeofKEvent();
private static final int KQUEUE_IDENT_OFFSET = Native.offsetofKEventIdent();
private static final int KQUEUE_FILTER_OFFSET = Native.offsetofKEventFilter();
private static final int KQUEUE_FFLAGS_OFFSET = Native.offsetofKEventFFlags();
private static final int KQUEUE_FLAGS_OFFSET = Native.offsetofKEventFlags();
private static final int KQUEUE_DATA_OFFSET = Native.offsetofKeventData();
private ByteBuffer memory;
private long memoryAddress;
private int size;
private int capacity;
KQueueEventArray(int capacity) {
if (capacity < 1) {
throw new IllegalArgumentException("capacity must be >= 1 but was " + capacity);
}
memory = Buffer.allocateDirectWithNativeOrder(calculateBufferCapacity(capacity));
memoryAddress = Buffer.memoryAddress(memory);
this.capacity = capacity;
}
/**
* Return the {@code memoryAddress} which points to the start of this {@link KQueueEventArray}.
*/
long memoryAddress() {
return memoryAddress;
}
/**
* Return the capacity of the {@link KQueueEventArray} which represent the maximum number of {@code kevent}s
* that can be stored in it.
*/
int capacity() {
return capacity;
}
int size() {
return size;
}
void clear() {
size = 0;
}
void evSet(AbstractKQueueChannel ch, short filter, short flags, int fflags) {
reallocIfNeeded();
evSet(getKEventOffset(size++) + memoryAddress, ch.socket.intValue(), filter, flags, fflags);
}
private void reallocIfNeeded() {
if (size == capacity) {
realloc(true);
}
}
/**
* Increase the storage of this {@link KQueueEventArray}.
*/
void realloc(boolean throwIfFail) {
// Double the capacity while it is "sufficiently small", and otherwise increase by 50%.
int newLength = capacity <= 65536 ? capacity << 1 : capacity + capacity >> 1;
try {
ByteBuffer buffer = Buffer.allocateDirectWithNativeOrder(calculateBufferCapacity(newLength));
// Copy over the old content of the memory and reset the position as we always act on the buffer as if
// the position was never increased.
memory.position(0).limit(size);
buffer.put(memory);
buffer.position(0);
Buffer.free(memory);
memory = buffer;
memoryAddress = Buffer.memoryAddress(buffer);
} catch (OutOfMemoryError e) {
if (throwIfFail) {
OutOfMemoryError error = new OutOfMemoryError(
"unable to allocate " + newLength + " new bytes! Existing capacity is: " + capacity);
error.initCause(e);
throw error;
}
}
}
/**
* Free this {@link KQueueEventArray}. Any usage after calling this method may segfault the JVM!
*/
void free() {
Buffer.free(memory);
memoryAddress = size = capacity = 0;
}
private static int getKEventOffset(int index) {
return index * KQUEUE_EVENT_SIZE;
}
private long getKEventOffsetAddress(int index) {
return getKEventOffset(index) + memoryAddress;
}
private short getShort(int index, int offset) {
if (PlatformDependent.hasUnsafe()) {
return PlatformDependent.getShort(getKEventOffsetAddress(index) + offset);
}
return memory.getShort(getKEventOffset(index) + offset);
}
short flags(int index) {
return getShort(index, KQUEUE_FLAGS_OFFSET);
}
short filter(int index) {
return getShort(index, KQUEUE_FILTER_OFFSET);
}
short fflags(int index) {
return getShort(index, KQUEUE_FFLAGS_OFFSET);
}
int fd(int index) {
if (PlatformDependent.hasUnsafe()) {
return PlatformDependent.getInt(getKEventOffsetAddress(index) + KQUEUE_IDENT_OFFSET);
}
return memory.getInt(getKEventOffset(index) + KQUEUE_IDENT_OFFSET);
}
long data(int index) {
if (PlatformDependent.hasUnsafe()) {
return PlatformDependent.getLong(getKEventOffsetAddress(index) + KQUEUE_DATA_OFFSET);
}
return memory.getLong(getKEventOffset(index) + KQUEUE_DATA_OFFSET);
}
private static int calculateBufferCapacity(int capacity) {
return capacity * KQUEUE_EVENT_SIZE;
}
private static native void evSet(long keventAddress, int ident, short filter, short flags, int fflags);
}