Use the ThreadPool for all isolates and native ports. Previously,

runtime/vm/isolate.h

Index: runtime/vm/isolate.h
===================================================================
--- runtime/vm/isolate.h	(revision 6423)
+++ runtime/vm/isolate.h	(working copy)
@@ -33,7 +33,6 @@
 class StubCode;
 class Zone;
 
-
 class Isolate : public BaseIsolate {
  public:
   ~Isolate();
@@ -144,8 +143,7 @@
   // value to trigger interrupts.
   uword stack_limit() const { return stack_limit_; }
 
-  // The true stack limit for this isolate.  This does not change
-  // after isolate initialization.
+  // The true stack limit for this isolate.
   uword saved_stack_limit() const { return saved_stack_limit_; }
 
   enum {
@@ -161,9 +159,6 @@
   MessageHandler* message_handler() const { return message_handler_; }
   void set_message_handler(MessageHandler* value) { message_handler_ = value; }
 
-  // Returns null on success, a RawError on failure.
-  RawError* StandardRunLoop();
-
   intptr_t ast_node_id() const { return ast_node_id_; }
   void set_ast_node_id(int value) { ast_node_id_ = value; }
 
@@ -226,6 +221,28 @@
   DISALLOW_COPY_AND_ASSIGN(Isolate);
 };
 
+class SetIsolateScope {

[siva, 2012/04/14 00:29:53]

In two out of the three places where this is used the saved_isolate_ must be
NULL (I think there should be an assertion for that).

[turnidge, 2012/04/17 23:46:55]

Added a new StartIsolateScope for those cases.

+ public:
+  explicit SetIsolateScope(Isolate* new_isolate)
+      : new_isolate_(new_isolate), saved_isolate_(Isolate::Current()) {
+    Isolate::SetCurrent(new_isolate);
+    if (new_isolate != NULL) {
+      new_isolate->SetStackLimitFromCurrentTOS(reinterpret_cast<uword>(this));
+    }
+  }
+
+  ~SetIsolateScope() {
+    ASSERT(Isolate::Current() == new_isolate_);
+    Isolate::SetCurrent(saved_isolate_);
+  }
+
+ private:
+  Isolate* new_isolate_;
+  Isolate* saved_isolate_;
+
+  DISALLOW_COPY_AND_ASSIGN(SetIsolateScope);
+};
+
 }  // namespace dart
 
 #endif  // VM_ISOLATE_H_