From cbcc04c1fb17d87f97d55862fc3d7ac959ed76ae Mon Sep 17 00:00:00 2001
From: hns <hannesw@gmail.com>
Date: Tue, 17 Oct 2006 11:44:51 +0000
Subject: [PATCH] * Set/Get current RequestEvaluator explicitly via ThreadLocal
 * Prevent NullpointerException when scripting engine is initialized   from
 non-request-evaluator thread   (merge from helma_1_5 branch)

---
 src/helma/framework/core/Application.java     | 22 +++++++++----------
 src/helma/framework/core/Prototype.java       |  3 ++-
 .../framework/core/RequestEvaluator.java      |  7 ++++++
 3 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/helma/framework/core/Application.java b/src/helma/framework/core/Application.java
index 915cf859..9880b61d 100644
--- a/src/helma/framework/core/Application.java
+++ b/src/helma/framework/core/Application.java
@@ -102,6 +102,9 @@ public final class Application implements IPathElement, Runnable {
     long requestTimeout = 60000;
     ThreadGroup threadgroup;
 
+    // threadlocal variable for the current RequestEvaluator
+    ThreadLocal currentEvaluator = new ThreadLocal();
+
     // Map of requesttrans -> active requestevaluators
     Hashtable activeRequests;
 
@@ -1192,18 +1195,15 @@ public final class Application implements IPathElement, Runnable {
      * @return the RequestEvaluator belonging to the current thread
      */
     public RequestEvaluator getCurrentRequestEvaluator() {
-        Thread thread = Thread.currentThread();
-        int l = allThreads.size();
+        return (RequestEvaluator) currentEvaluator.get();
+    }
 
-        for (int i = 0; i < l; i++) {
-            RequestEvaluator r = (RequestEvaluator) allThreads.get(i);
-
-            if ((r != null) && (r.getThread() == thread)) {
-                return r;
-            }
-        }
-
-        return null;
+    /**
+     * Set the current RequestEvaluator for the calling thread.
+     * @param eval the RequestEvaluator belonging to the current thread
+     */
+    protected void setCurrentRequestEvaluator(RequestEvaluator eval) {
+        currentEvaluator.set(eval);
     }
 
     /**
diff --git a/src/helma/framework/core/Prototype.java b/src/helma/framework/core/Prototype.java
index 517ef2a7..0c5a3a09 100644
--- a/src/helma/framework/core/Prototype.java
+++ b/src/helma/framework/core/Prototype.java
@@ -122,9 +122,10 @@ public final class Prototype {
             props.addResource(repository.getResource("type.properties"));
             if (update) {
                 RequestEvaluator eval = app.getCurrentRequestEvaluator();
+                ScriptingEngine engine = eval == null ? null : eval.scriptingEngine;
                 Iterator it = repository.getAllResources().iterator();
                 while (it.hasNext()) {
-                    checkResource((Resource) it.next(), eval.scriptingEngine);
+                    checkResource((Resource) it.next(), engine);
                 }
             }
         }
diff --git a/src/helma/framework/core/RequestEvaluator.java b/src/helma/framework/core/RequestEvaluator.java
index a4094672..5d462a89 100644
--- a/src/helma/framework/core/RequestEvaluator.java
+++ b/src/helma/framework/core/RequestEvaluator.java
@@ -79,6 +79,7 @@ public final class RequestEvaluator implements Runnable {
 
     /**
      *  Create a new RequestEvaluator for this application.
+     *  @param app the application
      */
     public RequestEvaluator(Application app) {
         this.app = app;
@@ -89,6 +90,7 @@ public final class RequestEvaluator implements Runnable {
             String engineClassName = app.getProperty("scriptingEngine",
                                                      "helma.scripting.rhino.RhinoEngine");
             try {
+                app.setCurrentRequestEvaluator(this);
                 Class clazz = app.getClassLoader().loadClass(engineClassName);
 
                 scriptingEngine = (ScriptingEngine) clazz.newInstance();
@@ -112,6 +114,8 @@ public final class RequestEvaluator implements Runnable {
                 } else {
                     throw new RuntimeException(t.toString());
                 }
+            } finally {
+                app.setCurrentRequestEvaluator(null);
             }
         }
     }
@@ -151,6 +155,7 @@ public final class RequestEvaluator implements Runnable {
 
                         // initialize scripting engine
                         initScriptingEngine();
+                        app.setCurrentRequestEvaluator(this);
                         // update scripting prototypes
                         scriptingEngine.updatePrototypes();
 
@@ -559,6 +564,8 @@ public final class RequestEvaluator implements Runnable {
                             res.reportError(app.getName(), error);
                             done = true;
                         }
+                    } finally {
+                        app.setCurrentRequestEvaluator(null);
                     }
                 }