/*
* JBoss, Home of Professional Open Source.
* Copyright 2011, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.as.controller;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicStampedReference;
/**
* The overall state of a process that is being managed by a {@link ModelController}.
*
* @author Brian Stansberry (c) 2011 Red Hat Inc.
*/
public class ControlledProcessState {
public static enum State {
/**
* The process is starting and its runtime state is being made consistent with its persistent configuration.
*/
STARTING("starting"),
/**
* The process is started, is running normally and has a runtime state consistent with its persistent configuration.
*/
RUNNING("running"),
/**
* The process requires a stop and re-start of its root service (but not a full process restart) in order to
* ensure stable operation and/or to bring its running state in line with its persistent configuration. A
* stop and restart of the root service (also known as a 'reload') will result in the removal of all other
* services and creation of new services based on the current configuration, so its affect on availability to
* handle external requests is similar to that of a full process restart. However, a reload can execute more
* quickly than a full process restart.
*/
RELOAD_REQUIRED("reload-required"),
/**
* The process must be terminated and replaced with a new process in order to ensure stable operation and/or to bring
* the running state in line with the persistent configuration.
*/
RESTART_REQUIRED("restart-required"),
/** The process is stopping. */
STOPPING("stopping"),
/** The process is stopped */
STOPPED("stopped");
private final String stringForm;
private State(final String stringForm) {
this.stringForm = stringForm;
}
@Override
public String toString() {
return stringForm;
}
}
private final AtomicInteger stamp = new AtomicInteger(0);
private final AtomicStampedReference<State> state = new AtomicStampedReference<State>(State.STARTING, 0);
private final boolean reloadSupported;
private final ControlledProcessStateService service;
private boolean restartRequiredFlag = false;
public ControlledProcessState(final boolean reloadSupported) {
this.reloadSupported = reloadSupported;
service = new ControlledProcessStateService(State.STOPPED);
}
public State getState() {
return state.getReference();
}
public boolean isReloadSupported() {
return reloadSupported;
}
public void setStarting() {
synchronized (service) {
state.set(State.STARTING, stamp.incrementAndGet());
service.stateChanged(State.STARTING);
}
}
public void setRunning() {
AtomicStampedReference<State> stateRef = state;
int newStamp = stamp.incrementAndGet();
int[] receiver = new int[1];
// Keep trying until stateRef is set with our stamp
for (;;) {
State was = stateRef.get(receiver);
if (was != State.STARTING) { // AS7-1103 only transition to running from STARTING
break;
}
synchronized (service) {
State newState = restartRequiredFlag ? State.RESTART_REQUIRED : State.RUNNING;
if (state.compareAndSet(was, newState, receiver[0], newStamp)) {
service.stateChanged(newState);
break;
}
}
}
}
public void setStopping() {
synchronized (service) {
state.set(State.STOPPING, stamp.incrementAndGet());
service.stateChanged(State.STOPPING);
}
}
public void setStopped() {
synchronized (service) {
state.set(State.STOPPED, stamp.incrementAndGet());
service.stateChanged(State.STOPPED);
}
}
public Object setReloadRequired() {
if (!reloadSupported) {
return setRestartRequired();
}
AtomicStampedReference<State> stateRef = state;
int newStamp = stamp.incrementAndGet();
int[] receiver = new int[1];
// Keep trying until stateRef is RELOAD_REQUIRED with our stamp
for (;;) {
State was = stateRef.get(receiver);
if (was == State.STARTING || was == State.STOPPING || was == State.RESTART_REQUIRED) {
break;
}
synchronized (service) {
if (stateRef.compareAndSet(was, State.RELOAD_REQUIRED, receiver[0], newStamp)) {
service.stateChanged(State.RELOAD_REQUIRED);
break;
}
}
}
return Integer.valueOf(newStamp);
}
public Object setRestartRequired() {
AtomicStampedReference<State> stateRef = state;
int newStamp = stamp.incrementAndGet();
int[] receiver = new int[1];
// Keep trying until stateRef is RESTART_REQUIRED with our stamp
for (;;) {
State was = stateRef.get(receiver);
if (was == State.STARTING || was == State.STOPPING) {
break;
}
synchronized (service) {
if (stateRef.compareAndSet(was, State.RESTART_REQUIRED, receiver[0], newStamp)) {
restartRequiredFlag = true;
service.stateChanged(State.RESTART_REQUIRED);
break;
}
}
}
return Integer.valueOf(newStamp);
};
public void revertReloadRequired(Object stamp) {
if (!reloadSupported) {
revertRestartRequired(stamp);
}
// If 'state' still has the state we last set in restartRequired(), change to RUNNING
Integer theirStamp = Integer.class.cast(stamp);
synchronized (service) {
if (state.compareAndSet(State.RELOAD_REQUIRED, State.RUNNING, theirStamp, this.stamp.incrementAndGet())) {
service.stateChanged(State.RUNNING);
}
}
}
public void revertRestartRequired(Object stamp) {
// If 'state' still has the state we last set in restartRequired(), change to RUNNING
Integer theirStamp = Integer.class.cast(stamp);
synchronized (service) {
if (state.compareAndSet(State.RESTART_REQUIRED, State.RUNNING, theirStamp, this.stamp.incrementAndGet())) {
restartRequiredFlag = false;
service.stateChanged(State.RUNNING);
}
}
}
ControlledProcessStateService getService() {
return service;
}
}