Index: kernel/generic/include/proc/task.h
===================================================================
--- kernel/generic/include/proc/task.h	(revision 7cfe5c035807f24eb685752e38192c922b60c893)
+++ kernel/generic/include/proc/task.h	(revision 497bd656d30dfa5181c542cab4d9d1807cbe1bbd)
@@ -95,8 +95,24 @@
 	
 	/* IPC stuff */
-	answerbox_t answerbox;  /**< Communication endpoint */
+
+	/** Receiving communication endpoint */
+	answerbox_t answerbox;
+
+	/** Sending communication endpoints */
 	phone_t phones[IPC_MAX_PHONES];
-	stats_ipc_t ipc_info;   /**< IPC statistics */
+
+	/** Spinlock protecting the active_calls list. */
+	SPINLOCK_DECLARE(active_calls_lock);
+
+	/**
+	 * List of all calls sent by this task that have not yet been
+	 * answered.
+	 */
+	list_t active_calls;
+
 	event_t events[EVENT_TASK_END - EVENT_END];
+
+	/** IPC statistics */
+	stats_ipc_t ipc_info;
 	
 #ifdef CONFIG_UDEBUG