Added reset functionality

src/SMAPI/Framework/PerformanceCounter/PerformanceCounter.cs

@@ -25,6 +25,12 @@ namespace StardewModdingAPI.Framework.PerformanceCounter
             this._counter = new CircularBuffer<PerformanceCounterEntry>(PerformanceCounter.MAX_ENTRIES);
         }
 
+        public void Reset()
+        {
+            this._counter.Clear();
+            this.PeakPerformanceCounterEntry = null;
+        }
+
         public int GetAverageCallsPerSecond()
         {
             var x = this._counter.GroupBy(

src/SMAPI/Framework/PerformanceCounter/PerformanceCounterManager.cs

@@ -16,6 +16,22 @@ namespace StardewModdingAPI.Framework.PerformanceCounter
             this.InitializePerformanceCounterEvents();
         }
 
+        public void Reset()
+        {
+            foreach (var performanceCounter in this.PerformanceCounterEvents)
+            {
+                this.ResetCategory(performanceCounter);
+            }
+        }
+
+        public void ResetCategory(EventPerformanceCounterCategory category)
+        {
+            foreach (var eventPerformanceCounter in category.Event.PerformanceCounters)
+            {
+                eventPerformanceCounter.Value.Reset();
+            }
+        }
+
         private void InitializePerformanceCounterEvents()
         {
             this.PerformanceCounterEvents = new HashSet<EventPerformanceCounterCategory>()

src/SMAPI/Framework/SCore.cs

@@ -498,8 +498,9 @@ namespace StardewModdingAPI.Framework
                 "Usage: performance_counters [name] [threshold]\n"+
                 "Shows detailed performance counters for a specific event\n"+
                 "- name: The (partial) name of the event\n"+
-                "- threshold: The minimum avg execution time (ms) of the event\n"+
+                "- threshold: The minimum avg execution time (ms) of the event\n\n"+
-                "", this.HandleCommand);
+                "Usage: performance_counters reset\n"+
+                "Resets all performance counters\n", this.HandleCommand);
             this.GameInstance.CommandManager.Add(null, "pc", "Alias for performance_counters", this.HandleCommand);
 
             // start handling command line input
@@ -1393,6 +1394,9 @@ namespace StardewModdingAPI.Framework
                             }
                         }
                         break;
+                    case "reset":
+                        this.PerformanceCounterManager.Reset();
+                        return;
                     default:
                         showSummary = false;
                         filterByName = arguments[0];