timings.diff

diff --git a/src/main/java/co/aikar/timings/FullServerTickHandler.java b/src/main/java/co/aikar/timings/FullServerTickHandler.java
index f6d61673..64531fcc 100644
--- a/src/main/java/co/aikar/timings/FullServerTickHandler.java
+++ b/src/main/java/co/aikar/timings/FullServerTickHandler.java
@@ -53,8 +53,7 @@ public class FullServerTickHandler extends TimingHandler {
         long start = System.nanoTime();
         TimingsManager.tick();
         long diff = System.nanoTime() - start;
-        CURRENT = TIMINGS_TICK;
-        TIMINGS_TICK.addDiff(diff);
+        TIMINGS_TICK.addDiff(diff, null);
         // addDiff for TIMINGS_TICK incremented this, bring it back down to 1 per tick.
         record.setCurTickCount(record.getCurTickCount()-1);
 
diff --git a/src/main/java/co/aikar/timings/NullTimingHandler.java b/src/main/java/co/aikar/timings/NullTimingHandler.java
index 8e0cd40e..9b45ce88 100644
--- a/src/main/java/co/aikar/timings/NullTimingHandler.java
+++ b/src/main/java/co/aikar/timings/NullTimingHandler.java
@@ -27,6 +27,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public final class NullTimingHandler implements Timing {
+    public static final Timing NULL = new NullTimingHandler();
     @NotNull
     @Override
     public Timing startTiming() {
diff --git a/src/main/java/co/aikar/timings/TimedEventExecutor.java b/src/main/java/co/aikar/timings/TimedEventExecutor.java
index 68f7866e..933ecf9b 100644
--- a/src/main/java/co/aikar/timings/TimedEventExecutor.java
+++ b/src/main/java/co/aikar/timings/TimedEventExecutor.java
@@ -76,8 +76,8 @@ public class TimedEventExecutor implements EventExecutor {
             executor.execute(listener, event);
             return;
         }
-        timings.startTiming();
-        executor.execute(listener, event);
-        timings.stopTiming();
+        try (Timing ignored = timings.startTiming()){
+            executor.execute(listener, event);
+        }
     }
 }
diff --git a/src/main/java/co/aikar/timings/Timing.java b/src/main/java/co/aikar/timings/Timing.java
index a562796c..a21e5ead 100644
--- a/src/main/java/co/aikar/timings/Timing.java
+++ b/src/main/java/co/aikar/timings/Timing.java
@@ -65,8 +65,9 @@ public interface Timing extends AutoCloseable {
     void stopTimingIfSync();
 
     /**
-     * Stops timing and disregards current timing data.
+     * @deprecated Doesn't do anything - Removed
      */
+    @Deprecated
     void abort();
 
     /**
diff --git a/src/main/java/co/aikar/timings/TimingHandler.java b/src/main/java/co/aikar/timings/TimingHandler.java
index 6bf8cb68..cc0390c0 100644
--- a/src/main/java/co/aikar/timings/TimingHandler.java
+++ b/src/main/java/co/aikar/timings/TimingHandler.java
@@ -25,21 +25,30 @@ package co.aikar.timings;
 
 import co.aikar.util.LoadingIntMap;
 import it.unimi.dsi.fastutil.ints.Int2ObjectOpenHashMap;
+
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
 import org.bukkit.Bukkit;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 class TimingHandler implements Timing {
 
     private static AtomicInteger idPool = new AtomicInteger(1);
+    private static Deque<TimingHandler> TIMING_STACK = new ArrayDeque<>();
     final int id = idPool.getAndIncrement();
 
-    final String name;
+    final TimingIdentifier identifier;
     private final boolean verbose;
 
     private final Int2ObjectOpenHashMap<TimingData> children = new LoadingIntMap<>(TimingData::new);
 
     final TimingData record;
+    private TimingHandler startParent;
     private final TimingHandler groupHandler;
 
     private long start = 0;
@@ -47,17 +56,10 @@ class TimingHandler implements Timing {
     private boolean added;
     private boolean timed;
     private boolean enabled;
-    private TimingHandler parent;
 
     TimingHandler(@NotNull TimingIdentifier id) {
-        if (id.name.startsWith("##")) {
-            verbose = true;
-            this.name = id.name.substring(3);
-        } else {
-            this.name = id.name;
-            verbose = false;
-        }
-
+        this.identifier = id;
+        this.verbose = id.name.startsWith("##");
         this.record = new TimingData(this.id);
         this.groupHandler = id.groupHandler;
 
@@ -96,35 +98,60 @@ class TimingHandler implements Timing {
 
     @NotNull
     public Timing startTiming() {
-        if (enabled && Bukkit.isPrimaryThread() && ++timingDepth == 1) {
+        if (!enabled || !Bukkit.isPrimaryThread()) {
+            return this;
+        }
+        if (++timingDepth == 1) {
+            startParent = TIMING_STACK.peekLast();
             start = System.nanoTime();
-            parent = TimingsManager.CURRENT;
-            TimingsManager.CURRENT = this;
         }
+        TIMING_STACK.addLast(this);
         return this;
     }
 
     public void stopTiming() {
-        if (enabled && timingDepth > 0 && Bukkit.isPrimaryThread() && --timingDepth == 0 && start != 0) {
-            addDiff(System.nanoTime() - start);
-            start = 0;
+        if (!enabled || timingDepth <= 0 || start == 0 || !Bukkit.isPrimaryThread()) {
+            return;
         }
-    }
 
-    @Override
-    public void abort() {
-        if (enabled && timingDepth > 0) {
+        popTimingStack();
+        if (--timingDepth == 0) {
+            addDiff(System.nanoTime() - start, startParent);
+            startParent = null;
             start = 0;
         }
     }
 
-    void addDiff(long diff) {
-        if (TimingsManager.CURRENT == this) {
-            TimingsManager.CURRENT = parent;
-            if (parent != null) {
-                parent.children.get(id).add(diff);
+    private void popTimingStack() {
+        TimingHandler last;
+        while ((last = TIMING_STACK.removeLast()) != this) {
+            last.timingDepth = 0;
+            String reportTo;
+            if ("Minecraft".equalsIgnoreCase(last.identifier.group)) {
+                reportTo = "Paper! This is a potential bug in Paper";
+            } else {
+                reportTo = "the plugin " + last.identifier.group + "(Look for errors above this in the logs)";
+            }
+            Logger.getGlobal().log(Level.SEVERE, "TIMING_STACK_CORRUPTION - Report this to " + reportTo + " (" + last.identifier + " did not stopTiming)", new Throwable());
+            boolean found = TIMING_STACK.contains(this);
+            if (!found) {
+                // We aren't even in the stack... Don't pop everything
+                TIMING_STACK.addLast(last);
+                break;
             }
         }
+    }
+
+    @Override
+    public final void abort() {
+
+    }
+
+    void addDiff(long diff, @Nullable TimingHandler parent) {
+        if (parent != null) {
+            parent.children.get(id).add(diff);
+        }
+
         record.add(diff);
         if (!added) {
             added = true;
@@ -132,7 +159,7 @@ class TimingHandler implements Timing {
             TimingsManager.HANDLERS.add(this);
         }
         if (groupHandler != null) {
-            groupHandler.addDiff(diff);
+            groupHandler.addDiff(diff, parent);
             groupHandler.children.get(id).add(diff);
         }
     }
diff --git a/src/main/java/co/aikar/timings/TimingHistory.java b/src/main/java/co/aikar/timings/TimingHistory.java
index 21b929f9..99815866 100644
--- a/src/main/java/co/aikar/timings/TimingHistory.java
+++ b/src/main/java/co/aikar/timings/TimingHistory.java
@@ -92,16 +92,13 @@ public class TimingHistory {
         }
         this.totalTicks = ticks;
         this.totalTime = FULL_SERVER_TICK.record.getTotalTime();
-        synchronized (TimingsManager.HANDLERS) {
-            this.entries = new TimingHistoryEntry[TimingsManager.HANDLERS.size()];
+        this.entries = new TimingHistoryEntry[TimingsManager.HANDLERS.size()];
 
-            int i = 0;
-            for (TimingHandler handler : TimingsManager.HANDLERS) {
-                entries[i++] = new TimingHistoryEntry(handler);
-            }
+        int i = 0;
+        for (TimingHandler handler : TimingsManager.HANDLERS) {
+            entries[i++] = new TimingHistoryEntry(handler);
         }
 
-
         // Information about all loaded chunks/entities
         //noinspection unchecked
         this.worlds = toObjectMapper(Bukkit.getWorlds(), new Function<World, JSONPair>() {
diff --git a/src/main/java/co/aikar/timings/TimingIdentifier.java b/src/main/java/co/aikar/timings/TimingIdentifier.java
index 4d140f34..df142a89 100644
--- a/src/main/java/co/aikar/timings/TimingIdentifier.java
+++ b/src/main/java/co/aikar/timings/TimingIdentifier.java
@@ -83,6 +83,11 @@ final class TimingIdentifier {
         return hashCode;
     }
 
+    @Override
+    public String toString() {
+        return "TimingIdentifier{id=" + group + ":" + name +'}';
+    }
+
     static class TimingGroup {
 
         private static AtomicInteger idPool = new AtomicInteger(1);
diff --git a/src/main/java/co/aikar/timings/TimingsExport.java b/src/main/java/co/aikar/timings/TimingsExport.java
index 4a69074a..65d312b0 100644
--- a/src/main/java/co/aikar/timings/TimingsExport.java
+++ b/src/main/java/co/aikar/timings/TimingsExport.java
@@ -162,9 +162,14 @@ class TimingsExport extends Thread {
                         if (!id.isTimed() && !id.isSpecial()) {
                             continue;
                         }
+
+                        String name = id.identifier.name;
+                        if (name.startsWith("##")) {
+                            name = name.substring(3);
+                        }
                         handlers.put(id.id, toArray(
                             group.id,
-                            id.name
+                            name
                         ));
                     }
                 }
diff --git a/src/main/java/co/aikar/timings/TimingsManager.java b/src/main/java/co/aikar/timings/TimingsManager.java
index 0109065d..ef824d70 100644
--- a/src/main/java/co/aikar/timings/TimingsManager.java
+++ b/src/main/java/co/aikar/timings/TimingsManager.java
@@ -50,11 +50,10 @@ public final class TimingsManager {
     public static List<String> hiddenConfigs = new ArrayList<String>();
     public static boolean privacy = false;
 
-    static final List<TimingHandler> HANDLERS = Collections.synchronizedList(new ArrayList<>(1024));
+    static final List<TimingHandler> HANDLERS = new ArrayList<>(1024);
     static final List<TimingHistory.MinuteReport> MINUTE_REPORTS = new ArrayList<>(64);
 
     static EvictingQueue<TimingHistory> HISTORY = EvictingQueue.create(12);
-    static TimingHandler CURRENT;
     static long timingStart = 0;
     static long historyStart = 0;
     static boolean needsFullReset = false;
@@ -77,14 +76,12 @@ public final class TimingsManager {
         if (Timings.timingsEnabled) {
             boolean violated = FULL_SERVER_TICK.isViolated();
 
-            synchronized (HANDLERS) {
-                for (TimingHandler handler : HANDLERS) {
-                    if (handler.isSpecial()) {
-                        // We manually call this
-                        continue;
-                    }
-                    handler.processTick(violated);
+            for (TimingHandler handler : HANDLERS) {
+                if (handler.isSpecial()) {
+                    // We manually call this
+                    continue;
                 }
+                handler.processTick(violated);
             }
 
             TimingHistory.playerTicks += Bukkit.getOnlinePlayers().size();
@@ -121,10 +118,8 @@ public final class TimingsManager {
         } else {
             // Soft resets only need to act on timings that have done something
             // Handlers can only be modified on main thread.
-            synchronized (HANDLERS) {
-                for (TimingHandler timings : HANDLERS) {
-                    timings.reset(false);
-                }
+            for (TimingHandler timings : HANDLERS) {
+                timings.reset(false);
             }
         }