Restart Manager service

The RestartManager service allows developers to perform framework and OS restarts on demand. Using the service one can:

• Perform different types of restarts, like restart the framework and clear its storage, restart the underlying OS, etc. Details are available in the next section.
• Perform a single restart, when installing several components that require one. As an instance, when installing a functionality distributed in several boot class path extensions, you can execute the restart after all the extensions are installed.
• Track the performed restarts and obtain information about them.

Registering bundle

The service is registered by System bundle.

Turning RestartManager on

The RestartManager service is registered under the com.prosyst.mbs.framework.restartmanager.RestartManager interface and is available when the mbs.restartmanager system property is set to true prior to framework startup.

Types of restarts

• Framework restart – It can be configured to execute the restart resetting the storage of the framework. The storage can be completely cleaned or can be restored from a specific location holding a predefined one.

  In the case of "storage factory reset", specify the following system properties:

  • mbs.storage.factory.url – The URL (local or remote) to a ZIP file from where the storage will be extracted upon storage factory reset.
  • mbs.storage.factory.bootcp – A semi-colon separated list holding the locations of the boot classpath extensions to the framework.
• OS restart - Supported only if the OSGi runtime is started through mBSA. It can be set up to execute the restart along with an OS factory reset if implemented for the underlying platform.

Initiating a system restart

To initiate a system restart, you have to call the restart method of the RestartManager service. The method requires three arguments:

• The type of the restart that will take place as an integer represented by the following RestartManager constants:
  • RESTART_OS – Indicates an OS restart.
  • RESTART_FW – Indicates a framework restart.
• A integer holding parameters for the restart – RestartManager.FW_FACTORY for storage factory reset of the framework, RestartManager.OS_FACTORY for OS factory reset, and RestartManager.NONE for no specific operations during the restart. The set of supported parameters is specific to the restart type.
• A String containing an explanation for the restart.

The code example from below contains an application that restarts the framework when a console command is issued. To supply the command, it implements the com.prosyst.util.pcommands.PluggableCommands interface. Then restart is called in the executeCommand method when the user executes the restartFW command or its shortcut rf.

This example shows how to use the RestartManager service:

package test.mbs.bundles.restart;    

import java.io.PrintStream;
import java.util.Hashtable;
import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import com.prosyst.mbs.framework.restartmanager.RestartManager;
import com.prosyst.util.pcommands.CommandInfo;
import com.prosyst.util.pcommands.PluggableCommands;    

public class RestartPluggableCommands implements BundleActivator, PluggableCommands {
  ServiceReference restartRef;
  RestartManager restartMngr;
  ServiceRegistration pluggableReg;

  final static String RESTART_REASON = "To test the Restart Manager";
  final static String RESTART_COMMAND = "restartFW";
  final static String RESTART_COMMAND_GROUP = "examples";
  final static String RESTART_COMMAND_SHORTCUT = "rf";    

  public void start(BundleContext bc) throws Exception {  
    // Retrieving the Restart Manager
    restartRef = bc.getServiceReference(RestartManager.class.getName());
    restartMngr = (RestartManager) bc.getService(restartRef);  
    // Registering a service for exporting console commands
    Hashtable regProps = new Hashtable(2);
    regProps.put("group", RESTART_COMMAND_GROUP);
    regProps.put("description", getGroupHelpMessage());
    pluggableReg = bc.registerService(PluggableCommands.class.getName(), this, regProps);
  }
      
  // Executes the "restartFW" command or its "rf" shortcut
  public void executeCommand(String name, String[] params, PrintStream pStream) {    
    if (name.equals(name) || name.equals(RESTART_COMMAND_SHORTCUT)) {
      restartMngr.restart(RestartManager.RESTART_FW, RestartManager.FW_FACTORY, null);
    }
  }

  public CommandInfo[] getCommandsInfo() {
    CommandInfo[] commands = new CommandInfo[1];
    String[] names = { RESTART_COMMAND, RESTART_COMMAND_SHORTCUT };
    commands[0] = new CommandInfo(names, "Restarts the framework", null);
    return commands;
  }

  public String getGroupHelpMessage() {    

    return "A command group to test the framework Restart Manager";
  }

  public String getGroupName() {      
    return RESTART_COMMAND_GROUP;
  }

  public void stop(BundleContext bc) throws Exception {
    pluggableReg.unregister();
    bc.ungetService(restartRef);
  }
}