Override WriteAsync in ShellStream

src/Renci.SshNet/ShellStream.cs

@@ -891,6 +891,57 @@ public override void WriteByte(byte value)
             Write([value]);
         }
 
+        /// <inheritdoc/>
+        public override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
+        {
+#if !NET
+            ThrowHelper.
+#endif
+            ValidateBufferArguments(buffer, offset, count);
+
+            return WriteAsync(buffer.AsMemory(offset, count), cancellationToken).AsTask();
+        }
+
+#if NET
+        /// <inheritdoc/>
+        public override async ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken = default)
+#else
+        private async ValueTask WriteAsync(ReadOnlyMemory<byte> buffer, CancellationToken cancellationToken)
+#endif
+        {
+            ThrowHelper.ThrowObjectDisposedIf(_disposed, this);
+
+            while (!buffer.IsEmpty)
+            {
+                if (_writeBuffer.AvailableLength == 0)
+                {
+                    await FlushAsync(cancellationToken).ConfigureAwait(false);
+                }
+
+                var bytesToCopy = Math.Min(buffer.Length, _writeBuffer.AvailableLength);
+
+                Debug.Assert(bytesToCopy > 0);
+
+                buffer.Slice(0, bytesToCopy).CopyTo(_writeBuffer.AvailableMemory);
+
+                _writeBuffer.Commit(bytesToCopy);
+
+                buffer = buffer.Slice(bytesToCopy);
+            }
+        }
+
+        /// <inheritdoc/>
+        public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback? callback, object? state)
+        {
+            return TaskToAsyncResult.Begin(WriteAsync(buffer, offset, count), callback, state);
+        }
+
+        /// <inheritdoc/>
+        public override void EndWrite(IAsyncResult asyncResult)
+        {
+            TaskToAsyncResult.End(asyncResult);
+        }
+
         /// <summary>
         /// Writes the line to the shell.
         /// </summary>

test/Renci.SshNet.Tests/Classes/ShellStreamTest_ReadExpect.cs

@@ -236,6 +236,21 @@ public void Read_AfterDispose_StillWorks()
             Assert.IsNull(_shellStream.ReadLine());
         }
 
+        [TestMethod]
+        public async Task ReadAsyncDoesNotBlockWriteAsync()
+        {
+            byte[] buffer = new byte[16];
+            Task<int> readTask = _shellStream.ReadAsync(buffer, 0, buffer.Length);
+
+            await _shellStream.WriteAsync("ls\n"u8.ToArray(), 0, 3);
+
+            Assert.IsFalse(readTask.IsCompleted);
+
+            _channelSessionStub.Receive("Directory.Build.props"u8.ToArray());
+
+            await readTask;
+        }
+
         [TestMethod]
         public void Read_MultiByte()
         {