Create isolates in a separate thread.

runtime/lib/isolate.cc

Index: runtime/lib/isolate.cc
diff --git a/runtime/lib/isolate.cc b/runtime/lib/isolate.cc
index f85726d1e02dc35b5a5fa8ee767d2f3ecb48bc7a..4a4dfd84500de4a2877b5ef9e5d9650d87e8f87e 100644
--- a/runtime/lib/isolate.cc
+++ b/runtime/lib/isolate.cc
@@ -2,6 +2,7 @@
 // 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.
 
+#include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
@@ -95,13 +96,6 @@ DEFINE_NATIVE_ENTRY(SendPortImpl_sendInternal_, 2) {
 }
 
 
-static void ThrowIsolateSpawnException(const String& message) {
-  const Array& args = Array::Handle(Array::New(1));
-  args.SetAt(0, message);
-  Exceptions::ThrowByType(Exceptions::kIsolateSpawn, args);
-}
-
-
 static bool CanonicalizeUri(Isolate* isolate,
                             const Library& library,
                             const String& uri,
@@ -139,58 +133,60 @@ static bool CanonicalizeUri(Isolate* isolate,
 }
 
 
-static bool CreateIsolate(Isolate* parent_isolate,
-                          IsolateSpawnState* state,
-                          char** error) {
-  Dart_IsolateCreateCallback callback = Isolate::CreateCallback();
-  if (callback == NULL) {
-    *error = strdup("Null callback specified for isolate creation\n");
-    Isolate::SetCurrent(parent_isolate);
-    return false;
-  }
-
-  void* init_data = parent_isolate->init_callback_data();
-  Isolate* child_isolate = reinterpret_cast<Isolate*>(
-      (callback)(state->script_url(),
-                 state->function_name(),
-                 init_data,
-                 error));
-  if (child_isolate == NULL) {
-    Isolate::SetCurrent(parent_isolate);
-    return false;
+class SpawnIsolateTask : public ThreadPool::Task {
+ public:
+  explicit SpawnIsolateTask(IsolateSpawnState* state)
+      : state_(state) {
   }
-  state->set_isolate(reinterpret_cast<Isolate*>(child_isolate));
 
-  Isolate::SetCurrent(parent_isolate);
-  return true;
-}
+  virtual void Run() {
+    // Create a new isolate.
+    char* error = NULL;
+    Dart_IsolateCreateCallback callback = Isolate::CreateCallback();
+    if (callback == NULL) {
+      ReportError(
+          "Isolate spawn is not supported by this Dart implementation.\n");
+      delete state_;
+      return;
+    }
 
+    Isolate* isolate = reinterpret_cast<Isolate*>(
+        (callback)(state_->script_url(),
+                   state_->function_name(),
+                   state_->init_data(),
+                   &error));
+    if (isolate == NULL) {
+      // We were unable to create the child isolate.  Report the error
+      // back to the parent isolate.
+      ReportError(error);
+      delete state_;
+      return;
+    }
 
-static RawObject* Spawn(Isolate* parent_isolate,
-                        IsolateSpawnState* state) {
-  // Create a new isolate.
-  char* error = NULL;
-  if (!CreateIsolate(parent_isolate, state, &error)) {
-    delete state;
-    const String& msg = String::Handle(String::New(error));
-    free(error);
-    ThrowIsolateSpawnException(msg);
+    MutexLocker ml(isolate->mutex());
+    state_->set_isolate(reinterpret_cast<Isolate*>(isolate));
+    isolate->set_spawn_state(state_);
+    if (isolate->is_runnable()) {
+      // Start the new isolate if it has been marked as runnable.
+      isolate->Run();
+    }
   }
 
-  // Create a SendPort for the new isolate.
-  Isolate* spawned_isolate = state->isolate();
-  const SendPort& port = SendPort::Handle(
-      SendPort::New(spawned_isolate->main_port()));
-
-  // Start the new isolate if it is already marked as runnable.
-  MutexLocker ml(spawned_isolate->mutex());
-  spawned_isolate->set_spawn_state(state);
-  if (spawned_isolate->is_runnable()) {
-    spawned_isolate->Run();
+ private:
+  void ReportError(const char* error) {
+    Dart_CObject error_cobj;
+    error_cobj.type = Dart_CObject_kString;
+    error_cobj.value.as_string = const_cast<char*>(error);
+    if (!Dart_PostCObject(state_->parent_port(), &error_cobj)) {
+      // Perhaps the parent isolate died or closed the port before we
+      // could report the error.  Ignore.
+    }
   }
 
-  return port.raw();
-}
+  IsolateSpawnState* state_;
+
+  DISALLOW_COPY_AND_ASSIGN(SpawnIsolateTask);
+};
 
 
 DEFINE_NATIVE_ENTRY(Isolate_spawnFunction, 3) {
@@ -206,7 +202,11 @@ DEFINE_NATIVE_ENTRY(Isolate_spawnFunction, 3) {
       ctx = Closure::context(closure);
       ASSERT(ctx.num_variables() == 0);
 #endif
-      return Spawn(isolate, new IsolateSpawnState(port.Id(), func, message));
+      Dart::thread_pool()->Run(new SpawnIsolateTask(
+          new IsolateSpawnState(port.Id(),
+                                isolate->init_callback_data(),
+                                func, message)));
+      return Object::null();
     }
   }
   const String& msg = String::Handle(String::New(
@@ -229,12 +229,18 @@ DEFINE_NATIVE_ENTRY(Isolate_spawnUri, 4) {
       Library::Handle(arguments->isolate()->object_store()->root_library());
   if (!CanonicalizeUri(arguments->isolate(), root_lib, uri,
                        &canonical_uri, &error)) {
-    const String& msg = String::Handle(String::New(error));
-    ThrowIsolateSpawnException(msg);
+    const String& message = String::Handle(String::New(error));
+    const Array& args = Array::Handle(Array::New(1));
+    args.SetAt(0, message);
+    Exceptions::ThrowByType(Exceptions::kIsolateSpawn, args);
   }
 
-  return Spawn(isolate, new IsolateSpawnState(port.Id(), canonical_uri,
-                                              args, message));
+  Dart::thread_pool()->Run(new SpawnIsolateTask(
+      new IsolateSpawnState(port.Id(),
+                            isolate->init_callback_data(),
+                            canonical_uri,
+                            args, message)));
+  return Object::null();
 }