org.apache.pulsar.shade.io.netty.util.NettyRuntime Maven / Gradle / Ivy
/*
* Copyright 2017 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 org.apache.pulsar.shade.io.netty.util;
import org.apache.pulsar.shade.io.netty.util.internal.ObjectUtil;
import org.apache.pulsar.shade.io.netty.util.internal.SystemPropertyUtil;
import java.util.Locale;
/**
* A utility class for wrapping calls to {@link Runtime}.
*/
public final class NettyRuntime {
/**
* Holder class for available processors to enable testing.
*/
static class AvailableProcessorsHolder {
private int availableProcessors;
/**
* Set the number of available processors.
*
* @param availableProcessors the number of available processors
* @throws IllegalArgumentException if the specified number of available processors is non-positive
* @throws IllegalStateException if the number of available processors is already configured
*/
synchronized void setAvailableProcessors(final int availableProcessors) {
ObjectUtil.checkPositive(availableProcessors, "availableProcessors");
if (this.availableProcessors != 0) {
final String message = String.format(
Locale.ROOT,
"availableProcessors is already set to [%d], rejecting [%d]",
this.availableProcessors,
availableProcessors);
throw new IllegalStateException(message);
}
this.availableProcessors = availableProcessors;
}
/**
* Get the configured number of available processors. The default is {@link Runtime#availableProcessors()}.
* This can be overridden by setting the system property "org.apache.pulsar.shade.io.netty.availableProcessors" or by invoking
* {@link #setAvailableProcessors(int)} before any calls to this method.
*
* @return the configured number of available processors
*/
@SuppressForbidden(reason = "to obtain default number of available processors")
synchronized int availableProcessors() {
if (this.availableProcessors == 0) {
final int availableProcessors =
SystemPropertyUtil.getInt(
"org.apache.pulsar.shade.io.netty.availableProcessors",
Runtime.getRuntime().availableProcessors());
setAvailableProcessors(availableProcessors);
}
return this.availableProcessors;
}
}
private static final AvailableProcessorsHolder holder = new AvailableProcessorsHolder();
/**
* Set the number of available processors.
*
* @param availableProcessors the number of available processors
* @throws IllegalArgumentException if the specified number of available processors is non-positive
* @throws IllegalStateException if the number of available processors is already configured
*/
@SuppressWarnings("unused,WeakerAccess") // this method is part of the public API
public static void setAvailableProcessors(final int availableProcessors) {
holder.setAvailableProcessors(availableProcessors);
}
/**
* Get the configured number of available processors. The default is {@link Runtime#availableProcessors()}. This
* can be overridden by setting the system property "org.apache.pulsar.shade.io.netty.availableProcessors" or by invoking
* {@link #setAvailableProcessors(int)} before any calls to this method.
*
* @return the configured number of available processors
*/
public static int availableProcessors() {
return holder.availableProcessors();
}
/**
* No public constructor to prevent instances from being created.
*/
private NettyRuntime() {
}
}