[Bug 340725] Make server-side exceptions easier to correlate with their client-side causes

https://bugs.eclipse.org/bugs/show_bug.cgi?id=340725

3 files changed, 65 insertions, 14 deletions

diff --git a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/buffer/BufferInputStream.java b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/buffer/BufferInputStream.java
index f0953e2d37..5e724c5625 100644
--- a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/buffer/BufferInputStream.java
+++ b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/buffer/BufferInputStream.java
@@ -10,6 +10,7 @@
  */
 package org.eclipse.net4j.buffer;
 
+import org.eclipse.net4j.signal.RemoteException;
 import org.eclipse.net4j.util.HexUtil;
 import org.eclipse.net4j.util.WrappedException;
 import org.eclipse.net4j.util.io.IOTimeoutException;
@@ -46,7 +47,7 @@ public class BufferInputStream extends InputStream implements IBufferHandler
 
   private boolean eos;
 
-  private RuntimeException exception;
+  private RemoteException exception;
 
   private long stopTimeMillis;
 
@@ -85,9 +86,9 @@ public class BufferInputStream extends InputStream implements IBufferHandler
   }
 
   /**
-   * @since 2.0
+   * @since 4.0
    */
-  public void setException(RuntimeException exception)
+  public void setException(RemoteException exception)
   {
     this.exception = exception;
   }
@@ -163,10 +164,7 @@ public class BufferInputStream extends InputStream implements IBufferHandler
       {
         while (currentBuffer == null)
         {
-          if (exception != null)
-          {
-            throw exception;
-          }
+          throwRemoteExceptionIfExists();
 
           if (buffers == null)
           {
@@ -182,10 +180,7 @@ public class BufferInputStream extends InputStream implements IBufferHandler
         restartTimeout();
         while (currentBuffer == null)
         {
-          if (exception != null)
-          {
-            throw exception;
-          }
+          throwRemoteExceptionIfExists();
 
           if (buffers == null)
           {
@@ -218,4 +213,14 @@ public class BufferInputStream extends InputStream implements IBufferHandler
     eos = currentBuffer.isEOS();
     return true;
   }
+
+  private void throwRemoteExceptionIfExists()
+  {
+    if (exception != null)
+    {
+      StackTraceElement[] stackTrace = Thread.currentThread().getStackTrace();
+      exception.setLocalStacktrace(stackTrace);
+      throw exception;
+    }
+  }
 }
diff --git a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RemoteException.java b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RemoteException.java
index a444a7fcb1..a0366110fe 100644
--- a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RemoteException.java
+++ b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RemoteException.java
@@ -20,9 +20,17 @@ public class RemoteException extends RuntimeException
 
   private boolean whileResponding;
 
-  public RemoteException(Throwable cause, boolean whileResponding)
+  private transient RequestWithConfirmation<?> localRequest;
+
+  private StackTraceElement[] localStackTrace;
+
+  /**
+   * @since 4.0
+   */
+  public RemoteException(Throwable remoteCause, RequestWithConfirmation<?> localRequest, boolean whileResponding)
   {
-    super(cause);
+    super(remoteCause);
+    this.localRequest = localRequest;
     this.whileResponding = whileResponding;
   }
 
@@ -36,4 +44,31 @@ public class RemoteException extends RuntimeException
   {
     return whileResponding;
   }
+
+  /**
+   * @since 4.0
+   */
+  public RequestWithConfirmation<?> getLocalRequest()
+  {
+    return localRequest;
+  }
+
+  /**
+   * @since 4.0
+   */
+  public void setLocalStacktrace(StackTraceElement[] stackTrace)
+  {
+    localStackTrace = stackTrace;
+  }
+
+  /**
+   * Returns the local stack as it stood at the time that the <i>remote</i> exception was detected <i>locally</i>. Note
+   * that no local problem occurred at the point in the code identified by this stacktrace.
+   * 
+   * @since 4.0
+   */
+  public StackTraceElement[] getLocalStackTrace()
+  {
+    return localStackTrace;
+  }
 }
diff --git a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RequestWithConfirmation.java b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RequestWithConfirmation.java
index 8fb539f835..95c47102d7 100644
--- a/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RequestWithConfirmation.java
+++ b/plugins/org.eclipse.net4j/src/org/eclipse/net4j/signal/RequestWithConfirmation.java
@@ -125,6 +125,17 @@ public abstract class RequestWithConfirmation<RESULT> extends SignalActor
 
   void setRemoteException(Throwable t, boolean responding)
   {
-    getBufferInputStream().setException(new RemoteException(t, responding));
+    RemoteException remoteException = getRemoteException(t, responding);
+    getBufferInputStream().setException(remoteException);
+  }
+
+  private RemoteException getRemoteException(Throwable t, boolean responding)
+  {
+    if (t instanceof RemoteException)
+    {
+      return (RemoteException)t;
+    }
+
+    return new RemoteException(t, this, responding);
   }
 }