Fix

dotnet · Feb 12, 2019 · ea5199c · ea5199c
1 parent 5129e3a
commit ea5199c
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Showing 2 changed files with 28 additions and 2 deletions.
diff --git a/src/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs b/src/System.IO.Pipelines/src/System/IO/Pipelines/Pipe.cs
@@ -264,6 +264,8 @@ private void ReturnSegments(BufferSegment from, BufferSegment toExclusive)
                 do
                 {
                     BufferSegment next = from.NextSegment;
+                    Debug.Assert(next != null || toExclusive == null);
+
                     from.ResetMemory();
 
                     if ((uint)index < (uint)segmentPool.Length)
@@ -440,6 +442,7 @@ private void AdvanceReader(BufferSegment consumedSegment, int consumedIndex, Buf
             BufferSegment returnEnd = null;
 
             CompletionData completionData = default;
+            bool isReadComplete;
 
             lock (_sync)
             {
@@ -517,15 +520,24 @@ private void AdvanceReader(BufferSegment consumedSegment, int consumedIndex, Buf
                     _readerAwaitable.SetUncompleted();
                 }
 
-                _operationState.EndRead();
+                isReadComplete = _operationState.TryEndRead();
             }
 
-            TrySchedule(_writerScheduler, completionData);
+            if (isReadComplete)
+            {
+                TrySchedule(_writerScheduler, completionData);
+            }
 
             if (returnStart != null && returnStart != returnEnd)
             {
                 ReturnSegments(returnStart, returnEnd);
             }
+
+            if (!isReadComplete)
+            {
+                // Segments need to be returned (above) prior to the throw.
+                ThrowHelper.ThrowInvalidOperationException_NoReadToComplete();
+            }
         }
 
         [MethodImpl(MethodImplOptions.AggressiveInlining)]

diff --git a/src/System.IO.Pipelines/src/System/IO/Pipelines/PipeOperationState.cs b/src/System.IO.Pipelines/src/System/IO/Pipelines/PipeOperationState.cs
@@ -46,6 +46,20 @@ public void EndRead()
             _state &= ~(State.Reading | State.ReadingTentative);
         }
 
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool TryEndRead()
+        {
+            if ((_state & State.Reading) != State.Reading &&
+                (_state & State.ReadingTentative) != State.ReadingTentative)
+            {
+                return false;
+            }
+
+            _state &= ~(State.Reading | State.ReadingTentative);
+            return true;
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void BeginWrite()
         {