Added support for isolate unhandled exceptions.

sdk/lib/isolate/base.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 class IsolateSpawnException implements Exception {
   const IsolateSpawnException(String this._s);
   String toString() => "IsolateSpawnException: '$_s'";
   final String _s;
 }
 
 /**
  * The initial [ReceivePort] available by default for this isolate. This
  * [ReceivePort] is created automatically and it is commonly used to establish
  * the first communication between isolates (see [spawnFunction] and
  * [spawnUri]).
  */
 external ReceivePort get port;
 
 /**
  * Creates and spawns an isolate that shares the same code as the current
  * isolate, but that starts from [topLevelFunction]. The [topLevelFunction]
  * argument must be a static top-level function or a static method that takes no
  * arguments. It is illegal to pass a function closure.

[siva, 2012/11/21 00:45:04]

We probably need some documentation here for the unhandledexception callback
parameter here.

[Tom Ball, 2012/11/21 05:22:38]

Done.

  *
  * When any isolate starts (even the main script of the application), a default
  * [ReceivePort] is created for it. This port is available from the top-level
  * getter [port] defined in this library.
  *
  * [spawnFunction] returns a [SendPort] derived from the child isolate's default
  * port.
  *
  * See comments at the top of this library for more details.
  */
 // Note this feature is not yet available in the dartvm.
-external SendPort spawnFunction(void topLevelFunction());
-
+external SendPort spawnFunction(void topLevelFunction(),
+    [bool UnhandledExceptionCallback(IsolateUnhandledException e)]);
 /**
  * Creates and spawns an isolate whose code is available at [uri].  Like with
  * [spawnFunction], the child isolate will have a default [ReceivePort], and a
  * this function returns a [SendPort] derived from it.

[siva, 2012/11/21 00:45:04]

Ditto comment regarding documentation of the unhandled exception callback
parameter.

[Tom Ball, 2012/11/21 05:22:38]

Done.

  *
  * See comments at the top of this library for more details.
  */
-external SendPort spawnUri(String uri);
+external SendPort spawnUri(String uri,
+    [bool UnhandledExceptionCallback(IsolateUnhandledException e)]);
 
 /**
  * [SendPort]s are created from [ReceivePort]s. Any message sent through
  * a [SendPort] is delivered to its respective [ReceivePort]. There might be
  * many [SendPort]s for the same [ReceivePort].
  *
  * [SendPort]s can be transmitted to other isolates.
  */
 abstract class SendPort {
 
@@ skipping 80 matching lines @@
   SendPort toSendPort();
 
 }
 
 // TODO(kasperl): Document this.
 abstract class SendPortSync {
 
   callSync(var message);
 
 }
+
+class _ReceivePortFactory {
+  external factory ReceivePort();
+}

[siva, 2012/11/21 00:45:04]

What is this change? Is it related to the UnhandledException stuff...

[Tom Ball, 2012/11/21 05:22:38]

I didn't write this, so I'm guessing it's related to the several hand-merges
I've done over the past week.  Deleted.

+
+/**
+ * Wraps unhandled exceptions thrown during isolate execution. It is
+ * used to show both the error message and the stack trace for unhandled
+ * exceptions.
+ */
+class IsolateUnhandledException implements Exception {
+  /** Message being handled when exception occurred. */
+  final message;
+
+  /** Wrapped exception. */
+  final source;
+
+  /** Trace for the wrapped exception. */
+  final Object stackTrace;
+
+  const IsolateUnhandledException(this.message, this.source, this.stackTrace);
+
+  String toString() {
+    return 'IsolateUnhandledException: exception while handling message: '
+        '${message} \n  '
+        '${source.toString().replaceAll("\n", "\n  ")}\n'
+        'original stack trace:\n  '
+        '${stackTrace.toString().replaceAll("\n","\n  ")}';
+  }
+}
+