Fixed deadlock caused by the message pump not being notified of new m…

…essage sends.

src/rt/rust_dom.cpp

@@ -314,7 +314,7 @@ rust_dom::start_main_loop() {
             }
             log(rust_log::TASK,
                 "all tasks are blocked, scheduler yielding ...");
-            sync::yield();
+            sync::sleep(100);
             log(rust_log::TASK,
                 "scheduler resuming ...");
             continue;

src/rt/rust_kernel.cpp

@@ -164,9 +164,7 @@ void
 rust_kernel::terminate_kernel_loop() {
     log(rust_log::KERN, "terminating kernel loop");
     _interrupt_kernel_loop = true;
-    _kernel_lock.lock();
-    _kernel_lock.signal_all();
-    _kernel_lock.unlock();
+    signal_kernel_lock();
     join();
 }
 
@@ -217,6 +215,23 @@ rust_kernel::free_handles(hash_map<T*, rust_handle<T>* > &map) {
     }
 }
 
+void
+rust_kernel::notify_message_enqueued(rust_message_queue *queue,
+                                     rust_message *message) {
+    // The message pump needs to handle this message if the queue is not
+    // associated with a domain, therefore signal the message pump.
+    if (queue->is_associated() == false) {
+        signal_kernel_lock();
+    }
+}
+
+void
+rust_kernel::signal_kernel_lock() {
+    _kernel_lock.lock();
+    _kernel_lock.signal_all();
+    _kernel_lock.unlock();
+}
+
 //
 // Local Variables:
 // mode: C++

src/rt/rust_kernel.h

@@ -9,6 +9,7 @@
  */
 
 class rust_kernel;
+class rust_message;
 
 template <typename T> class
 rust_handle :
@@ -90,6 +91,16 @@ class rust_kernel : public rust_thread {
 
     bool is_deadlocked();
 
+    void signal_kernel_lock();
+
+    /**
+     * Notifies the kernel whenever a message has been enqueued . This gives
+     * the kernel the opportunity to wake up the message pump thread if the
+     * message queue is not associated.
+     */
+    void
+    notify_message_enqueued(rust_message_queue *queue, rust_message *message);
+
     /**
      * Blocks until all domains have terminated.
      */

src/rt/rust_message.h

@@ -114,6 +114,11 @@ class rust_message_queue : public lock_free_queue<rust_message*>,
     bool is_associated() {
         return this->dom_handle != NULL;
     }
+
+    void enqueue(rust_message* message) {
+        lock_free_queue<rust_message*>::enqueue(message);
+        kernel->notify_message_enqueued(this, message);
+    }
 };
 
 //

src/rt/sync/lock_free_queue.h

@@ -120,7 +120,7 @@ class lock_free_queue {
         return head.node == tail.node;
     }
 
-    void enqueue(T value) {
+    virtual void enqueue(T value) {
 
         // Create a new node to be inserted in the linked list, and set the
         // next node to NULL.