srm: More Scheduler refactoring

Target: trunk
Require-notes: no
Require-book: no
Acked-by: Dmitry Litvintsev <litvinse@fnal.gov>
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/6209/

modules/srm-server/src/main/java/org/dcache/srm/scheduler/Scheduler.java

@@ -171,11 +171,11 @@ public final class Scheduler implements Runnable
 
     // this will contain the number of
     private final long timeStamp = System.currentTimeMillis();
-    private long queuesUpdateMaxWait = 60 * 1000; // one
+    private long queuesUpdateMaxWait = 60 * 1000;
 
     private static volatile Map<String, Scheduler> schedulers = ImmutableMap.of();
 
-    private volatile JobPriorityPolicyInterface jobAppraiser;
+    private JobPriorityPolicyInterface jobAppraiser;
     private String priorityPolicyPlugin;
 
     public static Scheduler getScheduler(String id)
@@ -243,35 +243,27 @@ public void schedule(Job job)
                 // fall through
             case RESTORED:
                 if (getTotalTQueued() >= getMaxThreadQueueSize()) {
-                    job.setState(State.FAILED, "Roo many jobs in the queue.");
+                    job.setState(State.FAILED, "Too many jobs in the queue.");
                     return;
                 }
-                // now we try to add the job to the thread queue without blocking
                 job.setState(State.TQUEUED, "Queued for execution.");
-                if (threadQueue(job)) {
-                    // offer returned true -> successfully added job to the queue
-                    return;
+                if (!threadQueue(job)) {
+                    LOGGER.warn("Thread queue limit reached.");
+                    job.setState(State.FAILED, "Site busy: too many queued requests.");
                 }
-
-                // if offer returned false or if it threw an exception,
-                // the job could not be scheduled, so it fails
-                job.setState(State.FAILED, "Site busy: too many queued requests.");
                 break;
             case ASYNCWAIT:
             case RETRYWAIT:
             case RUNNINGWITHOUTTHREAD:
-                // put blocks if priorityThreadQueue is full
-                // this will block the retry timer (or the event handler)
-                LOGGER.trace("putting job in a priority thread queue, which might block, job#{}", job.getId());
+                LOGGER.trace("putting job in a priority thread queue, job#{}", job.getId());
                 job.setState(State.PRIORITYTQUEUED, "queued for execution");
                 if (!priorityQueue(job)) {
-                    LOGGER.warn("Thread queue limit reached.");
+                    LOGGER.warn("Priority thread queue limit reached.");
                     job.setState(State.FAILED, "Site busy: too many queued requests.");
                 }
-                LOGGER.trace("done putting job in a priority thread queue");
                 break;
             default:
-                throw new IllegalStateException("can not schedule job in state =" + job.getState());
+                throw new IllegalStateException("cannot schedule job in state =" + job.getState());
             }
         } finally {
             job.wunlock();
@@ -656,16 +648,15 @@ public int calculateValue(
 
     public void tryToReadyJob(Job job)
     {
-        if (getTotalReady() >= maxReadyJobs) {
+        if (getTotalReady() >= getMaxReadyJobs()) {
             // can't add any more jobs to ready state
             return;
         }
         try {
             job.setState(State.READY, "Execution succeeded.");
         } catch (IllegalStateTransition ist) {
             //nothing more we can do here
-            LOGGER.error("Illegal State Transition : " + ist.getMessage());
-
+            LOGGER.error("Illegal State Transition : {}", ist.getMessage());
         }
     }
 
@@ -754,12 +745,10 @@ private boolean readyQueue(Job job)
         return false;
     }
 
-    private void jobAddedToQueue()
+    private synchronized void jobAddedToQueue()
     {
-        synchronized (this) {
-            notifyAll();
-            notified = true;
-        }
+        notified = true;
+        notifyAll();
     }
 
     @Override
@@ -802,8 +791,8 @@ public void run()
 
     private class JobWrapper implements Runnable
     {
-        Job job;
-        boolean started;
+        private final Job job;
+        private boolean started;
 
         public JobWrapper(Job job)
         {