package hudson.model;
import hudson.Extension;
import hudson.ExtensionList;
import hudson.ExtensionPoint;
import jenkins.model.Jenkins;
import java.io.IOException;
/**
* Extension point that allows plugins to veto the restart.
*
* @author Kohsuke Kawaguchi
* @since 1.376
*/
public abstract class RestartListener implements ExtensionPoint {
/**
* Called periodically during the safe restart.
*
* @return false to block the restart
*/
public abstract boolean isReadyToRestart() throws IOException, InterruptedException;
/**
* Called immediately before the restart is actually triggered.
*/
public void onRestart() {}
/**
* Returns all the registered {@link LabelFinder}s.
*/
public static ExtensionList<RestartListener> all() {
return Jenkins.getInstance().getExtensionList(RestartListener.class);
}
/**
* Returns true iff all the listeners OKed the restart.
*/
public static boolean isAllReady() throws IOException, InterruptedException {
for (RestartListener listener : all()) {
if (!listener.isReadyToRestart())
return false;
}
return true;
}
/**
* Default logic. Wait for all the executors to become idle.
*/
@Extension
public static class Default extends RestartListener {
@Override
public boolean isReadyToRestart() throws IOException, InterruptedException {
Jenkins h = Jenkins.getInstance();
return h.overallLoad.computeTotalExecutors() <= h.overallLoad.computeIdleExecutors();
}
}
}