Changeset 5399

Timestamp:

Sep 2, 2010, 2:09:15 PM (13 years ago)

Author:

Nicklas Nordborg

Message:

Fixes #1502: Add Signal.SHUTDOWN to plug-in signal system

The SHUTDOWN signal is now defined in the system and the job agent and internal job queue use this when shutting down (if supported by the plug-in, otherwise the ABORT signal is used).

No currently existing plug-ins support the SHUTDOWN signal and there is not support in the core or job agents to resume a job when the server starts up.

Location:

trunk/src

Files:

• clients/jobagent/net/sf/basedb/clients/jobagent/Agent.java (modified) (1 diff)
• clients/jobagent/net/sf/basedb/clients/jobagent/executors/ProcessJobExecutor.java (modified) (5 diffs)
• clients/web/net/sf/basedb/clients/web/util/SimpleSignalProgressReporter.java (modified) (3 diffs)
• core/net/sf/basedb/core/InternalJobQueue.java (modified) (1 diff)
• core/net/sf/basedb/core/signal/AbstractSignalReceiver.java (modified) (4 diffs)
• core/net/sf/basedb/core/signal/EnhancedThreadSignalHandler.java (added)
• core/net/sf/basedb/core/signal/ShutdownSignalSender.java (added)
• core/net/sf/basedb/core/signal/Signal.java (modified) (2 diffs)
• core/net/sf/basedb/core/signal/SignalReceiver.java (modified) (1 diff)
• core/net/sf/basedb/core/signal/SignalSender.java (added)
• core/net/sf/basedb/core/signal/SimpleSignalSender.java (added)

trunk/src/clients/jobagent/net/sf/basedb/clients/jobagent/Agent.java

@@ -935 +935 @@
     log.info("Stopping running jobs. " + activeJobs.size() + " job(s) still active.");
     
-    // Send ABORT to all jobs, that support signals
+    // Send SHUTDOWN/ABORT to all jobs, that support signals
     signalReceiver.close(closeTimeout);
   }

trunk/src/clients/jobagent/net/sf/basedb/clients/jobagent/executors/ProcessJobExecutor.java

@@ -31 +31 @@
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.List;
 
@@ -40 +41 @@
 import net.sf.basedb.core.PluginDefinition;
 import net.sf.basedb.core.SessionControl;
+import net.sf.basedb.core.signal.EnhancedThreadSignalHandler;
 import net.sf.basedb.core.signal.Signal;
 import net.sf.basedb.core.signal.SignalHandler;
 import net.sf.basedb.core.signal.SignalReceiver;
 import net.sf.basedb.core.signal.SignalTransporter;
-import net.sf.basedb.core.signal.ThreadSignalHandler;
 import net.sf.basedb.util.Values;
 
@@ -213 +214 @@
       {
         log.info("Waiting for process to end");
-        signalHandler = new ThreadSignalHandler();
+        // This handler will listen for SHUTDOWN signals only
+        signalHandler = new EnhancedThreadSignalHandler(Signal.SHUTDOWN);
         signalReceiver.registerSignalHandler(signalHandler);
         int exitCode = process.waitFor();
@@ -233 +235 @@
       catch (InterruptedException ex)
       {
-        log.info("Job was interrupted: " + job, ex);
-        // First, send ABORT to the job if it supports it
+        log.info("Job was interrupted (job agent is shutting down): " + job, ex);
+        // First, send SHUTDOWN/ABORT to the job if it supports it
         dc = sc.newDbControl();
         job = Job.getById(dc, job.getId());
@@ -240 +242 @@
         if (signalTransporter != null)
         {
-          signalTransporter.send(Signal.ABORT);
+          Collection<Signal> supported = signalTransporter.getSupportedSignals();
+          if (supported == null || supported.contains(Signal.SHUTDOWN))
+          {
+            signalTransporter.send(Signal.SHUTDOWN);
+          }
+          else
+          {
+            signalTransporter.send(Signal.ABORT);
+          }
         }
         else

trunk/src/clients/web/net/sf/basedb/clients/web/util/SimpleSignalProgressReporter.java

@@ -25 +25 @@
 import net.sf.basedb.core.ProgressReporter;
 import net.sf.basedb.core.SimpleProgressReporter;
+import net.sf.basedb.core.signal.ShutdownSignalSender;
 import net.sf.basedb.core.signal.Signal;
 import net.sf.basedb.core.signal.SignalException;
 import net.sf.basedb.core.signal.SignalHandler;
 import net.sf.basedb.core.signal.SignalReceiver;
+import net.sf.basedb.core.signal.SignalSender;
 import net.sf.basedb.core.signal.SignalTransporter;
+import net.sf.basedb.core.signal.SimpleSignalSender;
 
 /**
@@ -73 +76 @@
             public void run()
             {
-              sendToAll(Signal.ABORT);
+              sendToAll(new ShutdownSignalSender());
             }
           }
@@ -132 +135 @@
   }
 
-  /*  (non-Javadoc)
-      @see net.sf.basedb.core.signal.SignalReceiver#sendToAll(net.sf.basedb.core.signal.Signal)
-   */
   @Override
   public void sendToAll(Signal signal)
   {
-    if (handler == null) return;
-    logger.info("Sending " + signal);
-    // Copy the signal handler to a temporary collection,
-    // since sending a signal may cause a handler to get 
-    // unregistered, which may fail or block due to synchronization
-    SignalHandler tempHandler = null;
-    synchronized (handler)
-    {
-      try
-      {     
-        tempHandler = handler.getClass().newInstance();
-        if (tempHandler.supports(signal)) tempHandler.handleSignal(signal);
-      }
-      catch (Throwable th)
-      {}
-    }   
+    sendToAll(new SimpleSignalSender(signal));
+  }
+  
+  @Override
+  public void sendToAll(SignalSender sender)
+  {
+    // Copy the signal handler to a temporary variable,
+    // since other threads may unregister the handler
+    // while we are executing this method
+    SignalHandler tempHandler = handler;
+    if (tempHandler == null) return;
+    logger.info("Sending " + sender);
+    sender.sendTo(tempHandler);
   }
 

trunk/src/core/net/sf/basedb/core/InternalJobQueue.java

@@ -409 +409 @@
     sc.logout();
 
-    // Send ABORT to all jobs that supports signalling
+    // Send SHUTDOWN/ABORT to all jobs that supports signalling
     signalReceiver.close(closeTimeout);
   }

trunk/src/core/net/sf/basedb/core/signal/AbstractSignalReceiver.java

@@ -104 +104 @@
     should call <code>super.close()</code> if it wants to
     use the default shutdown notification to signal handlers. This
-    implementation will start a separate notification thread that sends
-    the {@link Signal#ABORT} signal to all registered handlers. The current 
-    thread will wait at most the given time. If the number of registered handlers
+    implementation will start a separate notification thread that first sends
+    the {@link Signal#SHUTDOWN} signal to all registered handlers, and then 
+    {@link Signal#ABORT} signal to all that are still alive after the shutdown signal. 
+    The current thread will wait at most the given time. If the number of registered handlers
     goes down to 0 before the time has ended the current thread will be awakened
     so it can continue. Note that the notification thread will usually finish in 
@@ -125 +126 @@
           public void run()
           {
-            logger.info("Sending ABORT to all handlers");
-            sendToAll(Signal.ABORT);
+            logger.info("Sending SHUTDOWN/ABORT to all handlers");
+            sendToAll(new ShutdownSignalSender());
           }
         }
@@ -202 +203 @@
   }
   
+  /**
+    @deprecated In 2.16, use {@link #sendToAll(SignalSender)} instead
+  */
+  @Override
+  @Deprecated
   public void sendToAll(Signal signal)
   {
+    sendToAll(new SimpleSignalSender(signal));
+  }
+  
+  @Override
+  public void sendToAll(SignalSender sender)
+  {
     if (handlers == null) return;
-    logger.info("Sending " + signal + " to " + (handlers.size()) + " handlers");
+    logger.info("Using " + sender + " to " + (handlers.size()) + " handlers");
     // Copy the signal handlers to a temporary collection,
     // since sending a signal may cause a handler to get 
@@ -216 +228 @@
     for (SignalHandler handler : temp)
     {
-      if (handler.supports(signal)) handler.handleSignal(signal);
+      sender.sendTo(handler);
     }
   }

trunk/src/core/net/sf/basedb/core/signal/Signal.java

@@ -42 +42 @@
   /**
     The ABORT signal, that requests that the receiver should
-    clean up and die.
+    clean up and die. This signal is typically sent to a plug-in
+    when the user manually requests that a job is aborted. It is
+    also sent when the system is shutting down to plug-ins that 
+    doesn't support the {@link #SHUTDOWN} signal.
   */
   public static final Signal ABORT = 
@@ -50 +53 @@
     );
 
+  /**
+    The SHUTDOWN signal, that requests that the receiver should
+    clean up and die. When the system is up again the receiver
+    may continue were it was stopped if supported. Otherwise, 
+    this signal should be treated as {@link #ABORT}.
+    @since 2.16
+  */
+  public static final Signal SHUTDOWN = 
+    registerSignal("SHUTDOWN", "Shutdown", 
+      "Sending this signal indicates that the system is shutting " +
+      "down. The receiver should stop whatever it is doing, " +
+      "cleanup allocated resource and exit. When the system is back " +
+      "up again, the reciever may continue working were it was stopped."
+    );
+
+  
   /**
     Holds all registered signals.

trunk/src/core/net/sf/basedb/core/signal/SignalReceiver.java

@@ -102 +102 @@
     the {@link Signal#ABORT} when the system is shutting down.
     @param signal The signal to send
+    @deprecated In 2.16, use {@link #sendToAll(SignalSender)} instead
   */
+  @Deprecated
   public void sendToAll(Signal signal);
   
+  /**
+    Let the signal sender send one or more signals to all registered
+    signal handlers on this reciever.
+    @param sender A signal sender implementation
+    @since 2.16
+  */
+  public void sendToAll(SignalSender sender);
+  
 }