From 8bdac589b88f3339bf7f4a4f9f4c1017a4cd296f Mon Sep 17 00:00:00 2001
From: Andrew Meadows <andrew@highfidelity.io>
Date: Sat, 9 Feb 2019 08:23:09 -0800
Subject: [PATCH] use RingBuffer for gradual garbage collection

---
 interface/src/Application.cpp        | 59 +++++++++++++++++-----------
 libraries/physics/src/ShapeManager.h |  8 +++-
 2 files changed, 43 insertions(+), 24 deletions(-)

diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 1029398794..b3c978df9a 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -6309,40 +6309,53 @@ void Application::update(float deltaTime) {
                 PROFILE_RANGE(simulation_physics, "PrePhysics");
                 PerformanceTimer perfTimer("prePhysics)");
                 {
+                    PROFILE_RANGE(simulation_physics, "RemoveEntities");
                     const VectorOfMotionStates& motionStates = _entitySimulation->getObjectsToRemoveFromPhysics();
                     _physicsEngine->removeObjects(motionStates);
                     _entitySimulation->deleteObjectsRemovedFromPhysics();
                 }
 
-                VectorOfMotionStates motionStates;
-                getEntities()->getTree()->withReadLock([&] {
-                    _entitySimulation->getObjectsToAddToPhysics(motionStates);
-                    _physicsEngine->addObjects(motionStates);
-
-                });
-                getEntities()->getTree()->withReadLock([&] {
-                    _entitySimulation->getObjectsToChange(motionStates);
-                    VectorOfMotionStates stillNeedChange = _physicsEngine->changeObjects(motionStates);
-                    _entitySimulation->setObjectsToChange(stillNeedChange);
-                });
+                {
+                    PROFILE_RANGE(simulation_physics, "AddEntities");
+                    VectorOfMotionStates motionStates;
+                    getEntities()->getTree()->withReadLock([&] {
+                        _entitySimulation->getObjectsToAddToPhysics(motionStates);
+                        _physicsEngine->addObjects(motionStates);
+                    });
+                }
+                {
+                    VectorOfMotionStates motionStates;
+                    PROFILE_RANGE(simulation_physics, "ChangeEntities");
+                    getEntities()->getTree()->withReadLock([&] {
+                        _entitySimulation->getObjectsToChange(motionStates);
+                        VectorOfMotionStates stillNeedChange = _physicsEngine->changeObjects(motionStates);
+                        _entitySimulation->setObjectsToChange(stillNeedChange);
+                    });
+                }
 
                 _entitySimulation->applyDynamicChanges();
 
                 t1 = std::chrono::high_resolution_clock::now();
 
-                PhysicsEngine::Transaction transaction;
-                avatarManager->buildPhysicsTransaction(transaction);
-                _physicsEngine->processTransaction(transaction);
-                avatarManager->handleProcessedPhysicsTransaction(transaction);
-                myAvatar->getCharacterController()->buildPhysicsTransaction(transaction);
-                _physicsEngine->processTransaction(transaction);
-                myAvatar->getCharacterController()->handleProcessedPhysicsTransaction(transaction);
-                myAvatar->prepareForPhysicsSimulation();
-                _physicsEngine->enableGlobalContactAddedCallback(myAvatar->isFlying());
+                {
+                    PROFILE_RANGE(simulation_physics, "Avatars");
+                    PhysicsEngine::Transaction transaction;
+                    avatarManager->buildPhysicsTransaction(transaction);
+                    _physicsEngine->processTransaction(transaction);
+                    avatarManager->handleProcessedPhysicsTransaction(transaction);
+                    myAvatar->getCharacterController()->buildPhysicsTransaction(transaction);
+                    _physicsEngine->processTransaction(transaction);
+                    myAvatar->getCharacterController()->handleProcessedPhysicsTransaction(transaction);
+                    myAvatar->prepareForPhysicsSimulation();
+                    _physicsEngine->enableGlobalContactAddedCallback(myAvatar->isFlying());
+                }
 
-                _physicsEngine->forEachDynamic([&](EntityDynamicPointer dynamic) {
-                    dynamic->prepareForPhysicsSimulation();
-                });
+                {
+                    PROFILE_RANGE(simulation_physics, "PrepareActions");
+                    _physicsEngine->forEachDynamic([&](EntityDynamicPointer dynamic) {
+                        dynamic->prepareForPhysicsSimulation();
+                    });
+                }
             }
             auto t2 = std::chrono::high_resolution_clock::now();
             {
diff --git a/libraries/physics/src/ShapeManager.h b/libraries/physics/src/ShapeManager.h
index 47b6c5340a..7583b7d919 100644
--- a/libraries/physics/src/ShapeManager.h
+++ b/libraries/physics/src/ShapeManager.h
@@ -12,6 +12,8 @@
 #ifndef hifi_ShapeManager_h
 #define hifi_ShapeManager_h
 
+#include <vector>
+
 #include <btBulletDynamicsCommon.h>
 #include <LinearMath/btHashMap.h>
 
@@ -41,6 +43,7 @@
 // later.  When that list grows big enough the ShapeManager will remove any matching
 // entries that still have zero ref-count.
 
+
 class ShapeManager {
 public:
 
@@ -75,7 +78,10 @@ private:
 
     // btHashMap is required because it supports memory alignment of the btCollisionShapes
     btHashMap<HashKey, ShapeReference> _shapeMap;
-    btAlignedObjectArray<uint64_t> _pendingGarbage;
+    //btAlignedObjectArray<uint64_t> _pendingGarbage;
+
+    std::vector<uint64_t> _garbageRing;
+    uint32_t _ringIndex { 0 };
 };
 
 #endif // hifi_ShapeManager_h