70 lines
1.9 KiB
Java
70 lines
1.9 KiB
Java
/*
|
|
* Copyright 2012 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;
|
|
|
|
|
|
import io.netty.util.internal.PlatformDependent;
|
|
|
|
import java.util.concurrent.ConcurrentMap;
|
|
|
|
/**
|
|
* A special {@link Error} which is used to signal some state or request by throwing it.
|
|
* {@link Signal} has an empty stack trace and has no cause to save the instantiation overhead.
|
|
*/
|
|
public final class Signal extends Error {
|
|
|
|
private static final long serialVersionUID = -221145131122459977L;
|
|
|
|
private static final ConcurrentMap<String, Boolean> map = PlatformDependent.newConcurrentHashMap();
|
|
|
|
private final UniqueName uname;
|
|
|
|
/**
|
|
* Create a new instance
|
|
*
|
|
* @param name the name under which it is registered
|
|
*/
|
|
public Signal(String name) {
|
|
super(name);
|
|
uname = new UniqueName(map, name);
|
|
}
|
|
|
|
/**
|
|
* Check if the given {@link Signal} is the same as this instance. If not an {@link IllegalStateException} will
|
|
* be thrown.
|
|
*/
|
|
public void expect(Signal signal) {
|
|
if (this != signal) {
|
|
throw new IllegalStateException("unexpected signal: " + signal);
|
|
}
|
|
}
|
|
|
|
@Override
|
|
public Throwable initCause(Throwable cause) {
|
|
return this;
|
|
}
|
|
|
|
@Override
|
|
public Throwable fillInStackTrace() {
|
|
return this;
|
|
}
|
|
|
|
@Override
|
|
public String toString() {
|
|
return uname.name();
|
|
}
|
|
}
|