VM thread shutdown.

runtime/vm/message_handler.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/message_handler.h"
 
 #include "vm/dart.h"
 #include "vm/lockers.h"
 #include "vm/os.h"
 #include "vm/port.h"
 #include "vm/thread_interrupter.h"
 
 
 namespace dart {
 
 DECLARE_FLAG(bool, trace_isolates);
 DECLARE_FLAG(bool, trace_service_pause_events);
 
 class MessageHandlerTask : public ThreadPool::Task {
  public:
   explicit MessageHandlerTask(MessageHandler* handler)
       : handler_(handler) {
     ASSERT(handler != NULL);
   }
 
   virtual void Run() {
+    ASSERT(handler_ != NULL);
     handler_->TaskCallback();
   }
 
  private:
   MessageHandler* handler_;
 
   DISALLOW_COPY_AND_ASSIGN(MessageHandlerTask);
 };
 
 
@@ skipping 38 matching lines @@
 
 void MessageHandler::MessageNotify(Message::Priority priority) {
   // By default, there is no custom message notification.
 }
 
 
 void MessageHandler::Run(ThreadPool* pool,
                          StartCallback start_callback,
                          EndCallback end_callback,
                          CallbackData data) {
+  bool task_running;
   MonitorLocker ml(&monitor_);
   if (FLAG_trace_isolates) {
     OS::Print("[+] Starting message handler:\n"
               "\thandler:    %s\n",
               name());
   }
   ASSERT(pool_ == NULL);
   pool_ = pool;
   start_callback_ = start_callback;
   end_callback_ = end_callback;
   callback_data_ = data;
   task_ = new MessageHandlerTask(this);
-  pool_->Run(task_);
+  task_running = pool_->Run(task_);
+  ASSERT(task_running);
 }
 
 
 void MessageHandler::PostMessage(Message* message, bool before_events) {
   Message::Priority saved_priority;
+  bool task_running = true;
   {
     MonitorLocker ml(&monitor_);
     if (FLAG_trace_isolates) {
       const char* source_name = "<native code>";
       Isolate* source_isolate = Isolate::Current();
       if (source_isolate) {
         source_name = source_isolate->name();
       }
       OS::Print("[>] Posting message:\n"
                 "\tlen:        %" Pd "\n"
                 "\tsource:     %s\n"
                 "\tdest:       %s\n"
                 "\tdest_port:  %" Pd64 "\n",
                 message->len(), source_name, name(), message->dest_port());
     }
 
     saved_priority = message->priority();
     if (message->IsOOB()) {
       oob_queue_->Enqueue(message, before_events);
     } else {
       queue_->Enqueue(message, before_events);
     }
     message = NULL;  // Do not access message.  May have been deleted.
 
-    if (pool_ != NULL && task_ == NULL) {
+    if ((pool_ != NULL) && (task_ == NULL)) {
       task_ = new MessageHandlerTask(this);
-      pool_->Run(task_);
+      task_running = pool_->Run(task_);
     }
   }
+  ASSERT(task_running);
+
   // Invoke any custom message notification.
   MessageNotify(saved_priority);
 }
 
 
 Message* MessageHandler::DequeueMessage(Message::Priority min_priority) {
   // TODO(turnidge): Add assert that monitor_ is held here.
   Message* message = oob_queue_->Dequeue();
   if ((message == NULL) && (min_priority < Message::kOOBPriority)) {
     message = queue_->Dequeue();
   }
   return message;
 }
 
 
 bool MessageHandler::HandleMessages(bool allow_normal_messages,
                                     bool allow_multiple_normal_messages) {
   // If isolate() returns NULL StartIsolateScope does nothing.
   StartIsolateScope start_isolate(isolate());
 
-  // ThreadInterrupter may have gone to sleep waiting while waiting for
+  // ThreadInterrupter may have gone to sleep while waiting for
   // an isolate to start handling messages.
   ThreadInterrupter::WakeUp();
 
   // TODO(turnidge): Add assert that monitor_ is held here.
   bool result = true;
   Message::Priority min_priority = (allow_normal_messages && !paused()) ?
       Message::kNormalPriority : Message::kOOBPriority;
   Message* message = DequeueMessage(min_priority);
   while (message != NULL) {
     intptr_t message_len = message->len();
@@ skipping 239 matching lines @@
 
 
 void MessageHandler::AcquireQueues(AcquiredQueues* acquired_queues) {
   ASSERT(acquired_queues != NULL);
   // No double dipping.
   ASSERT(acquired_queues->handler_ == NULL);
   acquired_queues->Reset(this);
 }
 
 }  // namespace dart