From afca5440f0c7b5e70966ea1b86422311e773b1a5 Mon Sep 17 00:00:00 2001
From: Seth Alves <seth.alves@gmail.com>
Date: Wed, 15 Apr 2015 10:58:56 -0700
Subject: [PATCH] entity-server will automatically clear simulation-owner ID if
 it doesn't get an update for 2 seconds

---
 libraries/entities/src/EntityItem.h           |  2 +-
 .../entities/src/SimpleEntitySimulation.cpp   | 28 +++++++++++++++++++
 .../entities/src/SimpleEntitySimulation.h     |  1 +
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/libraries/entities/src/EntityItem.h b/libraries/entities/src/EntityItem.h
index 8f7feb2ed8..946efea39c 100644
--- a/libraries/entities/src/EntityItem.h
+++ b/libraries/entities/src/EntityItem.h
@@ -323,7 +323,7 @@ protected:
     quint64 _lastEdited; // last official local or remote edit time
 
     quint64 _lastEditedFromRemote; // last time we received and edit from the server
-    quint64 _lastEditedFromRemoteInRemoteTime; // last time we received and edit from the server (in server-time-frame)
+    quint64 _lastEditedFromRemoteInRemoteTime; // last time we received an edit from the server (in server-time-frame)
     quint64 _created;
     quint64 _changedOnServer;
 
diff --git a/libraries/entities/src/SimpleEntitySimulation.cpp b/libraries/entities/src/SimpleEntitySimulation.cpp
index 6d45768c26..6846a38cb0 100644
--- a/libraries/entities/src/SimpleEntitySimulation.cpp
+++ b/libraries/entities/src/SimpleEntitySimulation.cpp
@@ -13,8 +13,12 @@
 
 #include "EntityItem.h"
 #include "SimpleEntitySimulation.h"
+#include "EntitiesLogging.h"
+
+const quint64 AUTO_REMOVE_SIMULATION_OWNER_USEC = 2000000;
 
 void SimpleEntitySimulation::updateEntitiesInternal(const quint64& now) {
+    // now is usecTimestampNow()
     QSet<EntityItem*>::iterator itemItr = _movingEntities.begin();
     while (itemItr != _movingEntities.end()) {
         EntityItem* entity = *itemItr;
@@ -27,6 +31,22 @@ void SimpleEntitySimulation::updateEntitiesInternal(const quint64& now) {
             ++itemItr;
         }
     }
+
+    // If an Entity has a simulation owner and we don't get an update for some amount of time,
+    // clear the owner.  This guards against an interface failing to release the Entity when it
+    // has finished simulating it.
+    itemItr = _hasSimulationOwnerEntities.begin();
+    while (itemItr != _hasSimulationOwnerEntities.end()) {
+        EntityItem* entity = *itemItr;
+        if (!entity->getSimulatorID().isEmpty() &&
+            usecTimestampNow() - entity->getLastChangedOnServer() >= AUTO_REMOVE_SIMULATION_OWNER_USEC) {
+            qCDebug(entities) << "auto-removing simulation owner" << entity->getSimulatorID();
+            entity->setSimulatorID("");
+            itemItr = _hasSimulationOwnerEntities.erase(itemItr);
+        } else {
+            ++itemItr;
+        }
+    }
 }
 
 void SimpleEntitySimulation::addEntityInternal(EntityItem* entity) {
@@ -35,11 +55,15 @@ void SimpleEntitySimulation::addEntityInternal(EntityItem* entity) {
     } else if (entity->getCollisionsWillMove()) {
         _movableButStoppedEntities.insert(entity);
     }
+    if (!entity->getSimulatorID().isEmpty()) {
+        _hasSimulationOwnerEntities.insert(entity);
+    }
 }
 
 void SimpleEntitySimulation::removeEntityInternal(EntityItem* entity) {
     _movingEntities.remove(entity);
     _movableButStoppedEntities.remove(entity);
+    _hasSimulationOwnerEntities.remove(entity);
 }
 
 const int SIMPLE_SIMULATION_DIRTY_FLAGS = EntityItem::DIRTY_VELOCITY | EntityItem::DIRTY_MOTION_TYPE;
@@ -55,6 +79,9 @@ void SimpleEntitySimulation::entityChangedInternal(EntityItem* entity) {
             _movingEntities.remove(entity);
             _movableButStoppedEntities.remove(entity);
         }
+        if (!entity->getSimulatorID().isEmpty()) {
+            _hasSimulationOwnerEntities.insert(entity);
+        }
     }
     entity->clearDirtyFlags();
 }
@@ -62,5 +89,6 @@ void SimpleEntitySimulation::entityChangedInternal(EntityItem* entity) {
 void SimpleEntitySimulation::clearEntitiesInternal() {
     _movingEntities.clear();
     _movableButStoppedEntities.clear();
+    _hasSimulationOwnerEntities.clear();
 }
 
diff --git a/libraries/entities/src/SimpleEntitySimulation.h b/libraries/entities/src/SimpleEntitySimulation.h
index 92b6a28215..af79ec0131 100644
--- a/libraries/entities/src/SimpleEntitySimulation.h
+++ b/libraries/entities/src/SimpleEntitySimulation.h
@@ -30,6 +30,7 @@ protected:
 
     QSet<EntityItem*> _movingEntities;
     QSet<EntityItem*> _movableButStoppedEntities;
+    QSet<EntityItem*> _hasSimulationOwnerEntities;
 };
 
 #endif // hifi_SimpleEntitySimulation_h