* Catch Linkage- and VirtualMachineErrors in scheduler loops in order to

keep on trucking in the face of OutOfMemoryErrors and the like.
* Sleep first, then do the work in scheduler loop.

src/helma/framework/core/Application.java

@@ -1452,25 +1452,12 @@ public final class Application implements Runnable {
         // interval between session cleanups
         long lastSessionCleanup = System.currentTimeMillis();
 
-        // logEvent ("Starting scheduler for "+name);
-
         while (Thread.currentThread() == worker) {
 
-            // purge sessions
             try {
-                lastSessionCleanup = cleanupSessions(lastSessionCleanup);
+                // interval between scheduler runs
-            } catch (Exception x) {
-                logError("Error in session cleanup", x);
-            }
-
-            // execute cron jobs
-            try {
-                executeCronJobs();
-            } catch (Exception x) {
-                logError("Error in cron job execution", x);
-            }
-
                 long sleepInterval = 60000;
+
                 try {
                     String sleepProp = props.getProperty("schedulerInterval");
                     if (sleepProp != null) {
@@ -1489,6 +1476,28 @@ public final class Application implements Runnable {
                     worker = null;
                     break;
                 }
+
+                // purge sessions
+                try {
+                    lastSessionCleanup = cleanupSessions(lastSessionCleanup);
+                } catch (Exception x) {
+                    logError("Error in session cleanup: " + x, x);
+                } catch (LinkageError x) {
+                    logError("Error in session cleanup: " + x, x);
+                }
+
+                // execute cron jobs
+                try {
+                    executeCronJobs();
+                } catch (Exception x) {
+                    logError("Error in cron job execution: " + x, x);
+                } catch (LinkageError x) {
+                    logError("Error in cron job execution: " + x, x);
+                }
+
+            } catch (VirtualMachineError error) {
+                logError("Error in scheduler loop: " + error, error);
+            }
         }
 
         // when interrupted, shutdown running cron jobs