cleaned up request handling

src/helma/framework/core/RequestEvaluator.java

@@ -121,28 +121,25 @@ public class RequestEvaluator implements Runnable {
     }
 
 
-    /* private void startThread () {
-	rtx = new Transactor (this, app.nmgr);
-	evaluator.thread = rtx;
-	rtx.start ();
-	// yield to make sure the transactor thread reaches waiting status before the first
-	// invocation request comes in
-	Thread.yield ();
-    }  */
-
     public void run () {
 
         int txcount = 0;
+        // first, set a local variable to the current transactor thread so we know
+        // when it's time to quit because another thread took over.
+        Transactor localrtx = (Transactor) Thread.currentThread ();
 
+        // evaluators are only initialized as needed, so we need to check that here
         if (!initialized)
 	app.typemgr.initRequestEvaluator (this);
 
+        try {
 	do {
 
 	    // make sure there is only one thread running per instance of this class
-	Transactor tx = rtx;
+	    if (localrtx != rtx) {
-	if (Thread.currentThread () != tx)
+	        localrtx.closeConnections ();
 	        return;
+	    }
 
 	    // IServer.getLogger().log ("got request "+reqtype);
 
@@ -160,9 +157,9 @@ public class RequestEvaluator implements Runnable {
 
 	                String requestPath = app.getName()+"/"+req.path;
 	                // set Timer to get some profiling data
-	        tx.timer.reset ();
+	                localrtx.timer.reset ();
-	        tx.timer.beginEvent (requestPath+" init");
+	                localrtx.timer.beginEvent (requestPath+" init");
-	        tx.begin (requestPath);
+	                localrtx.begin (requestPath);
 
 	                Action action = null;
 
@@ -192,7 +189,6 @@ public class RequestEvaluator implements Runnable {
 	                    } else {
 
 	                        // march down request path...
-
 	                        // is the next path element a subnode or a property of the last one?
 	                        // currently only used for users node
 	                        boolean isProperty = false;
@@ -277,51 +273,56 @@ public class RequestEvaluator implements Runnable {
 	                    current = getNodeWrapper (root);
 	                }
 
-	        tx.timer.endEvent (requestPath+" init");
+	                localrtx.timer.endEvent (requestPath+" init");
 
 	                try {
-	            tx.timer.beginEvent (requestPath+" execute");
+	                    localrtx.timer.beginEvent (requestPath+" execute");
 	                    current.doIndirectCall (evaluator, current, action.getFunctionName (), new ESValue[0]);
-	            tx.timer.endEvent (requestPath+" execute");
+	                    localrtx.timer.endEvent (requestPath+" execute");
 	                    done = true;
 	                } catch (RedirectException redirect) {
 	                    res.redirect = redirect.getMessage ();
 	                    done = true;
 	                }
 
-	        // check if we're still on track
+	                // check if we're still the one and only or if the waiting thread has given up on us already
-	        if (tx == rtx)
+	                commitTransaction ();
-	            tx.commit ();
-	        else
-	             throw new TimeoutException ();
 	                done = true;
 
 	            } catch (ConcurrencyException x) {
-	        try { tx.abort (); } catch (Exception ignore) {}
+
 	                res.reset ();
-	        if (++tries < 8) {
+	                if (++tries < 10) {
+	                    // try again after waiting some period
+	                    abortTransaction (true);
 	                    try {
 	                        // wait a bit longer with each try
-	                int base = 500 * tries;
+	                        int base = 200 * tries;
 	                        Thread.currentThread ().sleep ((long) (base + Math.random ()*base*2));
 	                    } catch (Exception ignore) {}
 	                    continue;
-	        }
+	                } else {
+	                    abortTransaction (false);
 	                    app.errorCount += 1;
 	                    res.write ("<b>Error in application '"+app.getName()+"':</b> <br><br><pre>Couldn't complete transaction due to heavy object traffic (tried "+tries+" times).</pre>");
 	                    done = true;
+	                }
 
 	            } catch (FrameworkException x) {
-	        try { tx.abort (); } catch (Exception ignore) {}
+
+	                abortTransaction (false);
+
 	                app.errorCount += 1;
 	                res.reset ();
 	                res.write ("<b>Error in application '"+app.getName()+"':</b> <br><br><pre>" + x.getMessage () + "</pre>");
 	                if (app.debug)
 	                    x.printStackTrace ();
-
 	                done = true;
+
 	            } catch (Exception x) {
-	        try { tx.abort (); } catch (Exception ignore) {}
+
+	                abortTransaction (false);
+
 	                app.errorCount += 1;
 	                System.err.println ("### Exception in "+app.getName()+"/"+req.path+": current = "+currentNode);
 	                System.err.println (x);
@@ -332,8 +333,8 @@ public class RequestEvaluator implements Runnable {
 
 	                // If the transactor thread has been killed by the invoker thread we don't have to
 	                // bother for the error message, just quit.
-	        if (rtx != tx)
+	                if (localrtx != rtx)
-	            return;
+	                    break;
 
 	                res.reset ();
 	                res.write ("<b>Error in application '"+app.getName()+"':</b> <br><br><pre>" + x.getMessage () + "</pre>");
@@ -343,7 +344,7 @@ public class RequestEvaluator implements Runnable {
 	        break;
 	    case XMLRPC:
 	        try {
-	        tx.begin (app.getName()+":xmlrpc/"+method);
+	            localrtx.begin (app.getName()+":xmlrpc/"+method);
 
 	            root = app.getDataRoot ();
 
@@ -383,14 +384,17 @@ public class RequestEvaluator implements Runnable {
 	            }
 	
 	            result = FesiRpcUtil.convertE2J (current.doIndirectCall (evaluator, current, method, esa));
-	        tx.commit ();
+	            commitTransaction ();
+
 	        } catch (Exception wrong) {
-	        try { tx.abort (); } catch (Exception ignore) {}
+
+	            abortTransaction (false);
 
 	            // If the transactor thread has been killed by the invoker thread we don't have to
 	            // bother for the error message, just quit.
-	        if (evaluator.thread != Thread.currentThread())
+	            if (localrtx != rtx) {
 	                return;
+	            }
 
 	            this.exception = wrong;
 	        }
@@ -401,7 +405,7 @@ public class RequestEvaluator implements Runnable {
 	        // Just a human readable descriptor of this invocation
 	        String funcdesc = app.getName()+":internal/"+method;
 	        try {
-	        tx.begin (funcdesc);
+	            localrtx.begin (funcdesc);
 
 	            root = app.getDataRoot ();
 
@@ -422,14 +426,17 @@ public class RequestEvaluator implements Runnable {
 	                }
 	            }
 	            esresult = current.doIndirectCall (evaluator, current, method, new ESValue[0]);
-	        tx.commit ();
+	            commitTransaction ();
+
 	        } catch (Throwable wrong) {
-	        try { tx.abort (); } catch (Exception ignore) {}
+
+	            abortTransaction (false);
 
 	            // If the transactor thread has been killed by the invoker thread we don't have to
 	            // bother for the error message, just quit.
-	        if (evaluator.thread != Thread.currentThread())
+	            if (localrtx != rtx) {
 	                return;
+	            }
 
 	            String msg = wrong.getMessage ();
 	            if (msg == null || msg.length () == 0)
@@ -440,26 +447,60 @@ public class RequestEvaluator implements Runnable {
 	        break;
 
 	    }
-	reqtype = NONE;
 
 	    // create a new Thread every 1000 requests. The current one will fade out
 	    if (txcount++ > 1000) {
-	    stopThread (); // stop thread - a new one will be created when needed
+	        // stop thread - a new one will be created when needed
+	        localrtx.closeConnections ();
 	        break;
 	    }
 
-	synchronized (this) {
+	    notifyAndWait ();
+
+            }  while (localrtx == rtx);
+
+        } finally {
+            localrtx.closeConnections ();
+        }
+    }
+
+    /**
+     * Called by the transactor thread when it has successfully fulfilled a request.
+     */
+    synchronized void commitTransaction () throws Exception {
+	Transactor localrtx = (Transactor) Thread.currentThread ();
+	if (localrtx == rtx) {
+	    reqtype = NONE;
+	    localrtx.commit ();
+	} else {
+	    throw new TimeoutException ();
+	}
+    }
+
+    synchronized void abortTransaction (boolean retry) {
+	Transactor localrtx = (Transactor) Thread.currentThread ();
+	if (!retry && localrtx == rtx)
+	    reqtype = NONE;
+	try {
+	    localrtx.abort ();
+	} catch (Exception ignore) {}
+    }
+
+    /**
+     * Tell waiting thread that we're done, then wait for next request
+     */
+    synchronized void notifyAndWait () {
+	Transactor localrtx = (Transactor) Thread.currentThread ();
+	if (reqtype != NONE)
+	    return;
 	notifyAll ();
 	try {
 	    wait ();
 	} catch (InterruptedException ir) {
-	        Thread.currentThread ().interrupt ();
+	    localrtx.closeConnections ();
 	}
     }
 
-        }  while (evaluator.thread == Thread.currentThread () && evaluator.thread == rtx);
-    }
-
     public synchronized ResponseTrans invoke (RequestTrans req, User user)  throws Exception {
 	this.reqtype = HTTP;
 	this.req = req;
@@ -468,7 +509,7 @@ public class RequestEvaluator implements Runnable {
 
 	checkThread ();
 	wait (app.requestTimeout);
- 	if (reqtype > 0) {
+ 	if (reqtype != NONE) {
 	    IServer.getLogger().log ("Stopping Thread for Request "+app.getName()+"/"+req.path);
 	    stopThread ();
 	    res.reset ();
@@ -489,7 +530,7 @@ public class RequestEvaluator implements Runnable {
 
 	checkThread ();
 	wait (app.requestTimeout);
- 	if (reqtype > 0) {
+ 	if (reqtype != NONE) {
 	    stopThread ();
 	}
 
@@ -521,7 +562,7 @@ public class RequestEvaluator implements Runnable {
 	checkThread ();
 	wait (60000l*15); // give internal call more time (15 minutes) to complete
 
- 	if (reqtype > 0) {
+ 	if (reqtype != NONE) {
 	    stopThread ();
 	}
 
@@ -543,7 +584,7 @@ public class RequestEvaluator implements Runnable {
 	checkThread ();
 	wait (app.requestTimeout);
 
- 	if (reqtype > 0) {
+ 	if (reqtype != NONE) {
 	    stopThread ();
 	}
 
@@ -559,17 +600,20 @@ public class RequestEvaluator implements Runnable {
      */
     public synchronized void stopThread () {
 	// IServer.getLogger().log ("Stopping Thread");
-	evaluator.thread = null;
 	Transactor t = rtx;
+	evaluator.thread = null;
 	rtx = null;
 	if (t != null) {
 	    if (reqtype != NONE) {
-	        try { t.abort (); } catch (Exception ignore) {}
+	        try {
+	            t.abort ();
+	        } catch (Exception ignore) {}
 	        t.kill ();
+	        reqtype = NONE;
 	    } else {
                      notifyAll ();
 	    }
-	    t.cleanup ();
+	    t.closeConnections ();
 	}
     }
 
@@ -590,7 +634,9 @@ public class RequestEvaluator implements Runnable {
      *  in those places when wrappers have to be updated if they already exist.
      */
     public ESNode getNodeWrapperFromCache (INode n) {
-        return n == null ? null : (ESNode) objectcache.get (n);
+	if (n == null)
+	    return null;
+	return (ESNode) objectcache.get (n);
     }
 
     public ESNode getNodeWrapper (INode n) {