Author: fmeschbe
Date: Fri Jul 27 22:33:49 2012
New Revision: 1366559
URL: http://svn.apache.org/viewvc?rev=1366559&view=rev
Log:
SLING-2489 Refactor start/stop logic such that doStart(URL) and doStop() are
completely symmetric and can be used to repeatedly start/stop the framework.
- Add proper shutdown hook handling
- Heuristically cleanup threads remaining after framework stop
(this may require more investigation)
Modified:
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/ControlListener.java
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/Main.java
Modified:
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/ControlListener.java
URL:
http://svn.apache.org/viewvc/sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/ControlListener.java?rev=1366559&r1=1366558&r2=1366559&view=diff
==============================================================================
---
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/ControlListener.java
(original)
+++
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/ControlListener.java
Fri Jul 27 22:33:49 2012
@@ -245,7 +245,7 @@ class ControlListener implements Runnabl
// the VM should stop. If there are still some non-daemon threads
// active, this will not happen, so we force this here ...
Main.info("Apache Sling terminated, exiting Java VM", null);
- slingMain.terminateVM(0);
+ Main.terminateVM(0);
}
// ---------- socket support
Modified:
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/Main.java
URL:
http://svn.apache.org/viewvc/sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/Main.java?rev=1366559&r1=1366558&r2=1366559&view=diff
==============================================================================
---
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/Main.java
(original)
+++
sling/trunk/launchpad/base/src/main/java/org/apache/sling/launchpad/app/Main.java
Fri Jul 27 22:33:49 2012
@@ -116,13 +116,13 @@ public class Main {
// check for control commands
int rc = main.doControlAction();
if (rc >= 0) {
- main.terminateVM(rc);
+ terminateVM(rc);
}
// finally start Sling
if (!main.doStart()) {
error("Failed to start Sling; terminating", null);
- main.terminateVM(1);
+ terminateVM(1);
}
}
@@ -184,6 +184,7 @@ public class Main {
this.commandLineArgs = (args == null)
? new HashMap<String, String>()
: args;
+
// sling.home from the command line or system properties, else default
String home = getSlingHome(commandLineArgs);
final File slingHomeFile = new File(home);
@@ -284,7 +285,7 @@ public class Main {
*
* @param status The application status exit code.
*/
- void terminateVM(final int status) {
+ static void terminateVM(final int status) {
System.exit(status);
}
@@ -316,6 +317,12 @@ public class Main {
* has been logged and <code>false</code> is returned.
*/
protected boolean doStart() {
+ // ensure up-to-date launcher jar
+ return doStart(getClass().getResource(
+ SharedConstants.DEFAULT_SLING_LAUNCHER_JAR));
+ }
+
+ protected boolean doStart(final URL launcherJar) {
// prevent duplicate start
if ( this.started) {
@@ -326,7 +333,6 @@ public class Main {
info("Starting Apache Sling in " + slingHome, null);
this.started = true;
- // The Loader helper
Loader loaderTmp = null;
try {
final File launchpadHome = getLaunchpadHome(slingHome,
@@ -345,51 +351,6 @@ public class Main {
}
this.loader = loaderTmp;
- // ensure up-to-date launcher jar
- return startSling(getClass().getResource(
- SharedConstants.DEFAULT_SLING_LAUNCHER_JAR));
- }
-
- /**
- * Maybe called by the application to cause the Sling Application to
- * properly terminate by stopping the OSGi Framework.
- * <p>
- * After calling this method the Sling Application can be started again
- * by calling the {@link #doStart()} method.
- * <p>
- * Calling this method multiple times without calling the {@link
#doStart()}
- * method in between has no effect after the Sling Application has been
- * terminated.
- */
- protected void doStop() {
- this.stopSling();
- }
-
- private void addShutdownHook() {
- if (this.shutdownHook == null) {
- this.shutdownHook = new Thread(new ShutdownHook(),
- "Apache Sling Terminator");
- Runtime.getRuntime().addShutdownHook(this.shutdownHook);
- }
- }
-
- private void removeShutdownHook() {
- // remove the shutdown hook, will fail if called from the
- // shutdown hook itself. Otherwise this prevents shutdown
- // from being called again
- Thread shutdownHook = this.shutdownHook;
- this.shutdownHook = null;
-
- if (shutdownHook != null) {
- try {
- Runtime.getRuntime().removeShutdownHook(shutdownHook);
- } catch (Throwable t) {
- // don't care for problems removing the hook
- }
- }
- }
-
- private boolean startSling(final URL launcherJar) {
if (launcherJar != null) {
try {
loader.installLauncherJar(launcherJar);
@@ -439,7 +400,18 @@ public class Main {
return false;
}
- void stopSling() {
+ /**
+ * Maybe called by the application to cause the Sling Application to
+ * properly terminate by stopping the OSGi Framework.
+ * <p>
+ * After calling this method the Sling Application can be started again
+ * by calling the {@link #doStart()} method.
+ * <p>
+ * Calling this method multiple times without calling the {@link
#doStart()}
+ * method in between has no effect after the Sling Application has been
+ * terminated.
+ */
+ protected void doStop() {
removeShutdownHook();
// now really shutdown sling
@@ -459,6 +431,30 @@ public class Main {
this.started = false;
}
+ private void addShutdownHook() {
+ if (this.shutdownHook == null) {
+ this.shutdownHook = new Thread(new ShutdownHook(),
+ "Apache Sling Terminator");
+ Runtime.getRuntime().addShutdownHook(this.shutdownHook);
+ }
+ }
+
+ private void removeShutdownHook() {
+ // remove the shutdown hook, will fail if called from the
+ // shutdown hook itself. Otherwise this prevents shutdown
+ // from being called again
+ Thread shutdownHook = this.shutdownHook;
+ this.shutdownHook = null;
+
+ if (shutdownHook != null) {
+ try {
+ Runtime.getRuntime().removeShutdownHook(shutdownHook);
+ } catch (Throwable t) {
+ // don't care for problems removing the hook
+ }
+ }
+ }
+
/**
* Define the sling.home parameter implementing the algorithme defined on
* the wiki page to find the setting according to this algorithm:
@@ -791,10 +787,56 @@ public class Main {
message), null);
}
+ /**
+ * Removes well-known stray threads and thread groups and removes framework
+ * thread context class loaders. Well-known stray threads and thread groups
+ * are:
+ * <ul>
+ * <li>The FileCleaningTracker$Reaper thread of the commons-io library</li>
+ * <li>The QuartzScheduler:ApacheSling thread group. See <a
+ * href="https://issues.apache.org/jira/browse/SLING-2535";>SLING-2535
+ * QuartzScheduler:ApacheSling thread group remaining after stopping the
+ * scheduler bundle</a></li>
+ * </ul>
+ */
+ static void cleanupThreads() {
+
+ // the current thread is the SlingNotifier thread part of
+ // the main thread group, whose parent is the system thread
+ // group. We only care for the main thread group here
+ ThreadGroup tg = Thread.currentThread().getThreadGroup();
+ Thread[] active = new Thread[tg.activeCount()];
+ tg.enumerate(active);
+ for (Thread thread : active) {
+ if (thread != null) {
+ if (thread.getName().equals("FileCleaningTracker$Reaper")) {
+ // I know, but this thread is stray ...
+ // Commons-IO bundle (or consumer of it) should
+ // actually stop it
+ thread.stop();
+ } else {
+ ClassLoader loader = thread.getContextClassLoader();
+ if (loader != null &&
loader.getClass().getName().startsWith("org.apache.felix.framework.")) {
+ thread.setContextClassLoader(null);
+ }
+ }
+ }
+ }
+
+ // SLING-2535 - Scheduler thread group
+ ThreadGroup[] groups = new ThreadGroup[tg.activeGroupCount()];
+ tg.enumerate(groups);
+ for (ThreadGroup group : groups) {
+ if (group != null &&
group.getName().equals("QuartzScheduler:ApacheSling")) {
+ group.destroy();
+ }
+ }
+ }
+
private class ShutdownHook implements Runnable {
public void run() {
- info("Java VM is shutting down", null);
- Main.this.stopSling();
+ Main.info("Java VM is shutting down", null);
+ Main.this.doStop();
}
}
@@ -818,7 +860,7 @@ public class Main {
Main.info("Apache Sling has been stopped", null);
Main.this.sling = null;
- Main.this.stopSling();
+ Main.this.doStop();
}
/**
@@ -837,14 +879,16 @@ public class Main {
public void updated(File updateFile) {
Main.this.sling = null;
- Main.this.stopSling();
+ Main.this.doStop();
+
+ Main.cleanupThreads();
if (updateFile == null) {
Main.info("Restarting Framework and Apache Sling", null);
- if (!Main.this.startSling(null)) {
+ if (!Main.this.doStart(null)) {
Main.error("Failed to restart Sling; terminating", null);
- Main.this.terminateVM(1);
+ Main.terminateVM(1);
}
} else {
@@ -853,7 +897,7 @@ public class Main {
"Restarting Framework with update from " + updateFile,
null);
boolean started = false;
try {
- started = Main.this.startSling(updateFile.toURI().toURL());
+ started = Main.this.doStart(updateFile.toURI().toURL());
} catch (MalformedURLException mue) {
Main.error("Cannot get URL for file " + updateFile, mue);
} finally {
@@ -862,7 +906,7 @@ public class Main {
if (!started) {
Main.error("Failed to restart Sling; terminating", null);
- Main.this.terminateVM(1);
+ Main.terminateVM(1);
}
}
}
