fix: 32bit-ARMv7 crashes on android

com.unity.netcode.gameobjects/Runtime/Messaging/NetworkBatchHeader.cs

@@ -12,6 +12,11 @@ internal struct NetworkBatchHeader : INetworkSerializeByMemcpy
         /// </summary>
         public ushort Magic;
 
+        /// <summary>
+        /// Total number of messages in the batch.
+        /// </summary>
+        public ushort BatchCount;
+
         /// <summary>
         /// Total number of bytes in the batch.
         /// </summary>
@@ -22,9 +27,5 @@ internal struct NetworkBatchHeader : INetworkSerializeByMemcpy
         /// </summary>
         public ulong BatchHash;
 
-        /// <summary>
-        /// Total number of messages in the batch.
-        /// </summary>
-        public ushort BatchCount;
     }
 }

com.unity.netcode.gameobjects/Runtime/Messaging/NetworkMessageManager.cs

@@ -33,6 +33,7 @@ public InvalidMessageStructureException(string issue) : base(issue)
 
     internal class NetworkMessageManager : IDisposable
     {
+        private const double k_WordAlignBatchCalc = 1.0 / 8.0;
         public bool StopProcessing = false;
 
         private struct ReceiveQueueItem
@@ -829,11 +830,17 @@ internal unsafe void ProcessSendQueues()
                     // Skipping the Verify and sneaking the write mark in because we know it's fine.
                     queueItem.Writer.Handle->AllowedWriteMark = sizeof(NetworkBatchHeader);
 #endif
-                    queueItem.BatchHeader.BatchHash = XXHash.Hash64(queueItem.Writer.GetUnsafePtr() + sizeof(NetworkBatchHeader), queueItem.Writer.Length - sizeof(NetworkBatchHeader));
 
-                    queueItem.BatchHeader.BatchSize = queueItem.Writer.Length;
+
+                    var alignedLength = (int)(Math.Ceiling(queueItem.Writer.Length * k_WordAlignBatchCalc) * 8);
+                    queueItem.Writer.TryBeginWrite(alignedLength);
+
+                    queueItem.BatchHeader.BatchHash = XXHash.Hash64(queueItem.Writer.GetUnsafePtr() + sizeof(NetworkBatchHeader), alignedLength - sizeof(NetworkBatchHeader));
+
+                    queueItem.BatchHeader.BatchSize = alignedLength;
 
                     queueItem.Writer.WriteValue(queueItem.BatchHeader);
+                    queueItem.Writer.Seek(alignedLength);
 
 
                     try

com.unity.netcode.gameobjects/Tests/Runtime/Metrics/TransportBytesMetricsTests.cs

@@ -41,7 +41,8 @@ public IEnumerator TrackTotalNumberOfBytesSent()
             }
 
             Assert.True(observer.Found);
-            Assert.AreEqual(FastBufferWriter.GetWriteSize(messageName) + k_MessageOverhead, observer.Value);
+            var expectedSize = (long)(Math.Ceiling((FastBufferWriter.GetWriteSize(messageName) + k_MessageOverhead) * (1.0f / 8.0f)) * 8.0f);
+            Assert.AreEqual(expectedSize, observer.Value);
         }
 
         [UnityTest]
@@ -61,8 +62,6 @@ public IEnumerator TrackTotalNumberOfBytesReceived()
                 writer.Dispose();
             }
 
-
-
             var nbFrames = 0;
             while (!observer.Found || nbFrames < 10)
             {
@@ -71,7 +70,8 @@ public IEnumerator TrackTotalNumberOfBytesReceived()
             }
 
             Assert.True(observer.Found);
-            Assert.AreEqual(FastBufferWriter.GetWriteSize(messageName) + k_MessageOverhead, observer.Value);
+            var expectedSize = (long)(Math.Ceiling((FastBufferWriter.GetWriteSize(messageName) + k_MessageOverhead) * (1.0f / 8.0f)) * 8.0f);
+            Assert.AreEqual(expectedSize, observer.Value);
         }
 
         private class TotalBytesObserver : IMetricObserver
@@ -89,12 +89,23 @@ public TotalBytesObserver(IMetricDispatcher dispatcher, DirectionalMetricInfo me
 
             public long Value { get; private set; }
 
+            private int m_BytesFoundCounter;
+            private long m_TotalBytes;
+
             public void Observe(MetricCollection collection)
             {
                 if (collection.TryGetCounter(m_MetricInfo.Id, out var counter) && counter.Value > 0)
                 {
-                    Found = true;
-                    Value = counter.Value;
+                    // Don't assign another observed value once one is already observed
+                    if (!Found)
+                    {
+                        Found = true;
+                        Value = counter.Value;
+                        var alignedSize = (long)(Math.Ceiling(counter.Value * 1.0f / 8.0f) * 8.0f);
+                        m_TotalBytes += alignedSize;
+                        m_BytesFoundCounter++;
+                        UnityEngine.Debug.Log($"[{m_BytesFoundCounter}] Bytes Observed {counter.Value} | Total Bytes Observed: {m_TotalBytes}");
+                    }
                 }
             }
         }