Make PathfindingSystem take a nap during large explosions (#12309)

Content.Server/Explosion/EntitySystems/ExplosionSystem.Processing.cs

@@ -63,7 +63,8 @@ public sealed partial class ExplosionSystem : EntitySystem
             return;
 
         _activeExplosion = null;
-        _nodeGroupSystem.Snoozing = false;
+        _nodeGroupSystem.PauseUpdating = false;
+        _pathfindingSystem.PauseUpdating = false;
     }
 
     /// <summary>
@@ -107,7 +108,8 @@ public sealed partial class ExplosionSystem : EntitySystem
                 // just a lil nap
                 if (SleepNodeSys)
                 {
-                    _nodeGroupSystem.Snoozing = true;
+                    _nodeGroupSystem.PauseUpdating = true;
+                    _pathfindingSystem.PauseUpdating = true;
                     // snooze grid-chunk regeneration?
                     // snooze power network (recipients look for new suppliers as wires get destroyed).
                 }
@@ -136,7 +138,8 @@ public sealed partial class ExplosionSystem : EntitySystem
                 // Ensure the system does not get stuck in an error-loop.
                 _activeExplosion = null;
                 RaiseNetworkEvent(new ExplosionOverlayUpdateEvent(_explosionCounter, int.MaxValue));
-                _nodeGroupSystem.Snoozing = false;
+                _nodeGroupSystem.PauseUpdating = false;
+                _pathfindingSystem.PauseUpdating = false;
                 throw;
             }
 #endif
@@ -163,7 +166,8 @@ public sealed partial class ExplosionSystem : EntitySystem
         RaiseNetworkEvent(new ExplosionOverlayUpdateEvent(_explosionCounter, int.MaxValue));
 
         //wakey wakey
-        _nodeGroupSystem.Snoozing = false;
+        _nodeGroupSystem.PauseUpdating = false;
+        _pathfindingSystem.PauseUpdating = false;
     }
 
     /// <summary>

Content.Server/Explosion/EntitySystems/ExplosionSystem.cs

@@ -3,6 +3,7 @@ using Content.Server.Administration.Logs;
 using Content.Server.Atmos.Components;
 using Content.Server.Explosion.Components;
 using Content.Server.NodeContainer.EntitySystems;
+using Content.Server.NPC.Pathfinding;
 using Content.Shared.Camera;
 using Content.Shared.Damage;
 using Content.Shared.Database;
@@ -32,6 +33,7 @@ public sealed partial class ExplosionSystem : EntitySystem
 
     [Dependency] private readonly DamageableSystem _damageableSystem = default!;
     [Dependency] private readonly NodeGroupSystem _nodeGroupSystem = default!;
+    [Dependency] private readonly PathfindingSystem _pathfindingSystem = default!;
     [Dependency] private readonly SharedCameraRecoilSystem _recoilSystem = default!;
     [Dependency] private readonly IAdminLogManager _adminLogger = default!;
     [Dependency] private readonly ThrowingSystem _throwingSystem = default!;
@@ -85,14 +87,16 @@ public sealed partial class ExplosionSystem : EntitySystem
     {
         _explosionQueue.Clear();
         _activeExplosion = null;
-        _nodeGroupSystem.Snoozing = false;
+        _nodeGroupSystem.PauseUpdating = false;
+        _pathfindingSystem.PauseUpdating = false;
     }
 
     public override void Shutdown()
     {
         base.Shutdown();
         UnsubscribeCvars();
-        _nodeGroupSystem.Snoozing = false;
+        _nodeGroupSystem.PauseUpdating = false;
+        _pathfindingSystem.PauseUpdating = false;
     }
 
     private void OnGetResistance(EntityUid uid, ExplosionResistanceComponent component, GetExplosionResistanceEvent args)

Content.Server/NPC/Pathfinding/PathfindingSystem.Grid.cs

@@ -27,6 +27,15 @@ public sealed partial class PathfindingSystem
     public const int PathfindingCollisionMask = (int) CollisionGroup.MobMask;
     public const int PathfindingCollisionLayer = (int) CollisionGroup.MobLayer;
 
+    /// <summary>
+    ///     If true, UpdateGrid() will not process grids.
+    /// </summary>
+    /// <remarks>
+    ///     Useful if something like a large explosion is in the process of shredding the grid, as it avoids uneccesary
+    ///     updating.
+    /// </remarks>
+    public bool PauseUpdating = false;
+
     private readonly Stopwatch _stopwatch = new();
 
     // Probably can't pool polys as there might be old pathfinding refs to them.
@@ -66,6 +75,9 @@ public sealed partial class PathfindingSystem
 
     private void UpdateGrid()
     {
+        if (PauseUpdating)
+            return;
+
         var curTime = _timing.CurTime;
 #if DEBUG
         var updateCount = 0;

Content.Server/NodeContainer/EntitySystems/NodeGroupSystem.cs

@@ -45,7 +45,14 @@ namespace Content.Server.NodeContainer.EntitySystems
         private int _gen = 1;
         private int _groupNetIdCounter = 1;
 
-        public bool Snoozing = false;
+        /// <summary>
+        ///     If true, UpdateGrid() will not process grids.
+        /// </summary>
+        /// <remarks>
+        ///     Useful if something like a large explosion is in the process of shredding the grid, as it avoids uneccesary
+        ///     updating.
+        /// </remarks>
+        public bool PauseUpdating = false;
 
         public override void Initialize()
         {
@@ -135,7 +142,7 @@ namespace Content.Server.NodeContainer.EntitySystems
         {
             base.Update(frameTime);
 
-            if (!Snoozing)
+            if (!PauseUpdating)
             {
                 DoGroupUpdates();
                 VisDoUpdate(frameTime);