private void stopIfAnyProcessDidNotStart() {
if (!lifecycle.tryToMoveTo(State.STARTED)) {
// stopping or stopped during startup, for instance :
// 1. A is started
// 2. B starts
// 3. A crashes while B is starting
// 4. if B was not monitored during Terminator execution, then it's an alive orphan
stop();
throw new IllegalStateException("Stopped during startup");
}
}
private void cleanAfterTermination() {
trace("go to STOPPED...");
if (lifecycle.tryToMoveTo(State.STOPPED)) {
trace("await termination of restartWatcher and hardStopWatcher...");
// wait for restartWatcher and hardStopWatcher to cleanly stop
awaitTermination(restartWatcher, hardStopWatcher);
trace("restartWatcher done");
// removing shutdown hook to avoid called stop() unnecessarily unless already in shutdownHook
if (!systemExit.isInShutdownHook()) {
trace("removing shutdown hook...");
Runtime.getRuntime().removeShutdownHook(shutdownHook);
}
// cleanly close JavaLauncher
closeJavaLauncher();
}
}
private void startProcesses() {
// do no start any child process if not in state INIT or RESTARTING (a stop could be in progress
// too)
if (lifecycle.tryToMoveTo(State.STARTING)) {
resetFileSystem();
// start watching for stop requested by other process (eg. orchestrator) if enabled and not
// started yet
if (watchForHardStop && hardStopWatcher == null) {
hardStopWatcher = new HardStopWatcherThread();
hardStopWatcher.start();
}
startAndMonitorProcesses();
stopIfAnyProcessDidNotStart();
}
}
/**
* Starts commands and blocks current thread until all processes are in state {@link
* State#STARTED}.
*
* @throws java.lang.IllegalArgumentException if commands list is empty
* @throws java.lang.IllegalStateException if already started or if at least one process failed to
* start. In this case all processes are terminated. No need to execute {@link #stop()}
*/
public void start(List<JavaCommand> commands) {
if (commands.isEmpty()) {
throw new IllegalArgumentException("At least one command is required");
}
if (lifecycle.getState() != State.INIT) {
throw new IllegalStateException("Can not start multiple times");
}
// intercepts CTRL-C
Runtime.getRuntime().addShutdownHook(shutdownHook);
// start watching for restart requested by child process
restartWatcher.start();
javaCommands = commands;
startProcesses();
}
public State getState() {
return lifecycle.getState();
}
public void restartAsync() {
if (lifecycle.tryToMoveTo(State.RESTARTING)) {
restartor = new RestartorThread();
restartor.start();
}
}
private void stopAsync(State stoppingState) {
assert stoppingState == State.STOPPING || stoppingState == State.HARD_STOPPING;
if (lifecycle.tryToMoveTo(stoppingState)) {
terminator.start();
}
}