Merge pull request #995 from booky10/fix/packet-sending-race-condition

Synchronize packet encoding
retrooper · Sep 20, 2024 · cb277bf · cb277bf
2 parents 02a565b + a3b4cc2
commit cb277bf
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Showing 2 changed files with 10 additions and 4 deletions.
diff --git a/api/src/main/java/com/github/retrooper/packetevents/manager/protocol/ProtocolManager.java b/api/src/main/java/com/github/retrooper/packetevents/manager/protocol/ProtocolManager.java
@@ -104,10 +104,13 @@ default Object[] transformWrappers(PacketWrapper<?> wrapper, Object channel, boo
         PacketWrapper<?>[] wrappers = PacketTransformationUtil.transform(wrapper);
         Object[] buffers = new Object[wrappers.length];
         for (int i = 0; i < wrappers.length; i++) {
-            wrappers[i].prepareForSend(channel, outgoing);
-            buffers[i] = wrappers[i].buffer;
-            // Fix race condition when sending packets to multiple people (due to when the buffer is freed)
-            wrappers[i].buffer = null;
+            PacketWrapper<?> wrappper = wrappers[i];
+            synchronized (wrappper.bufferLock) {
+                wrappper.prepareForSend(channel, outgoing);
+                buffers[i] = wrappper.buffer;
+                // Fix race condition when sending packets to multiple people (due to when the buffer is freed)
+                wrappper.buffer = null;
+            }
         }
         return buffers;
     }

diff --git a/api/src/main/java/com/github/retrooper/packetevents/wrapper/PacketWrapper.java b/api/src/main/java/com/github/retrooper/packetevents/wrapper/PacketWrapper.java
@@ -129,6 +129,9 @@ public class PacketWrapper<T extends PacketWrapper<T>> {
     @Nullable
     public Object buffer;
 
+    @ApiStatus.Internal
+    public final Object bufferLock = new Object();
+
     protected ClientVersion clientVersion;
     protected ServerVersion serverVersion;
     private PacketTypeData packetTypeData;