1 files changed, 15 insertions, 3 deletions
diff --git a/src/sim/drain.hh b/src/sim/drain.hh
index 663946616..7ff1d6e2a 100644
--- a/src/sim/drain.hh
+++ b/src/sim/drain.hh
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2012, 2015 ARM Limited
+ * Copyright (c) 2012, 2015, 2017 ARM Limited
  * All rights reserved
  *
  * The license below extends only to copyright in the software and shall
@@ -58,7 +58,11 @@ class Drainable;
  * all objects have entered the Drained state.
  *
  * Before resuming simulation, the simulator calls resume() to
- * transfer the object to the Running state.
+ * transfer the object to the Running state. This in turn results in a
+ * call to drainResume() for all Drainable objects in the
+ * simulator. New Drainable objects may be created while resuming. In
+ * such cases, the new objects will be created in the Resuming state
+ * and later resumed.
  *
  * \note Even though the state of an object (visible to the rest of
  * the world through Drainable::getState()) could be used to determine
@@ -68,7 +72,8 @@ class Drainable;
 enum class DrainState {
     Running,  /** Running normally */
     Draining, /** Draining buffers pending serialization/handover */
-    Drained   /** Buffers drained, ready for serialization/handover */
+    Drained,  /** Buffers drained, ready for serialization/handover */
+    Resuming, /** Transient state while the simulator is resuming */
 };
 #endif
 
@@ -153,6 +158,12 @@ class DrainManager
 
   private:
     /**
+     * Helper function to check if all Drainable objects are in a
+     * specific state.
+     */
+    bool allInState(DrainState state) const;
+
+    /**
      * Thread-safe helper function to get the number of Drainable
      * objects in a system.
      */
@@ -261,6 +272,7 @@ class Drainable
         switch (_drainState) {
           case DrainState::Running:
           case DrainState::Drained:
+          case DrainState::Resuming:
             return;
           case DrainState::Draining:
             _drainState = DrainState::Drained;