public async Task ServerShutsDownGracefullyWhenMaxRequestBufferSizeExceeded()
{
// Parameters
var data = new byte[_dataLength];
var bytesWrittenTimeout = TimeSpan.FromMilliseconds(100);
var bytesWrittenPollingInterval = TimeSpan.FromMilliseconds(bytesWrittenTimeout.TotalMilliseconds / 10);
var maxSendSize = 4096;
var startReadingRequestBody = new TaskCompletionSource <object>(TaskCreationOptions.RunContinuationsAsynchronously);
var clientFinishedSendingRequestBody = new TaskCompletionSource <object>(TaskCreationOptions.RunContinuationsAsynchronously);
var lastBytesWritten = DateTime.MaxValue;
var memoryPoolFactory = new DiagnosticMemoryPoolFactory(allowLateReturn: true);
using (var host = await StartWebHost(16 * 1024, data, false, startReadingRequestBody, clientFinishedSendingRequestBody, memoryPoolFactory.Create))
{
var port = host.GetPort();
using (var socket = CreateSocket(port))
using (var stream = new NetworkStream(socket))
{
await WritePostRequestHeaders(stream, data.Length);
var bytesWritten = 0;
Func <Task> sendFunc = async() =>
{
while (bytesWritten < data.Length)
{
var size = Math.Min(data.Length - bytesWritten, maxSendSize);
await stream.WriteAsync(data, bytesWritten, size).ConfigureAwait(false);
bytesWritten += size;
lastBytesWritten = DateTime.Now;
}
clientFinishedSendingRequestBody.TrySetResult(null);
};
var ignore = sendFunc();
// The minimum is (maxRequestBufferSize - maxSendSize + 1), since if bytesWritten is
// (maxRequestBufferSize - maxSendSize) or smaller, the client should be able to
// complete another send.
var minimumExpectedBytesWritten = (16 * 1024) - maxSendSize + 1;
// The maximum is harder to determine, since there can be OS-level buffers in both the client
// and server, which allow the client to send more than maxRequestBufferSize before getting
// paused. We assume the combined buffers are smaller than the difference between
// data.Length and maxRequestBufferSize.
var maximumExpectedBytesWritten = data.Length - 1;
// Block until the send task has gone a while without writing bytes AND
// the bytes written exceeds the minimum expected. This indicates the server buffer
// is full.
//
// If the send task is paused before the expected number of bytes have been
// written, keep waiting since the pause may have been caused by something else
// like a slow machine.
while ((DateTime.Now - lastBytesWritten) < bytesWrittenTimeout ||
bytesWritten < minimumExpectedBytesWritten)
{
await Task.Delay(bytesWrittenPollingInterval);
}
// Verify the number of bytes written before the client was paused.
Assert.InRange(bytesWritten, minimumExpectedBytesWritten, maximumExpectedBytesWritten);
// Dispose host prior to closing connection to verify the server doesn't throw during shutdown
// if a connection no longer has alloc and read callbacks configured.
await host.StopAsync();
host.Dispose();
}
}
// Allow appfunc to unblock
startReadingRequestBody.SetResult(null);
clientFinishedSendingRequestBody.SetResult(null);
await memoryPoolFactory.WhenAllBlocksReturned(TestConstants.DefaultTimeout);
}
public async Task LargeUpload(long?maxRequestBufferSize, bool connectionAdapter, bool expectPause)
{
// Parameters
var data = new byte[_dataLength];
var bytesWrittenTimeout = TimeSpan.FromMilliseconds(100);
var bytesWrittenPollingInterval = TimeSpan.FromMilliseconds(bytesWrittenTimeout.TotalMilliseconds / 10);
var maxSendSize = 4096;
var startReadingRequestBody = new TaskCompletionSource <object>(TaskCreationOptions.RunContinuationsAsynchronously);
var clientFinishedSendingRequestBody = new TaskCompletionSource <object>(TaskCreationOptions.RunContinuationsAsynchronously);
var lastBytesWritten = DateTime.MaxValue;
var memoryPoolFactory = new DiagnosticMemoryPoolFactory(allowLateReturn: true);
using (var host = await StartWebHost(maxRequestBufferSize, data, connectionAdapter, startReadingRequestBody, clientFinishedSendingRequestBody, memoryPoolFactory.Create))
{
var port = host.GetPort();
using (var socket = CreateSocket(port))
using (var stream = new NetworkStream(socket))
{
await WritePostRequestHeaders(stream, data.Length);
var bytesWritten = 0;
Func <Task> sendFunc = async() =>
{
while (bytesWritten < data.Length)
{
var size = Math.Min(data.Length - bytesWritten, maxSendSize);
await stream.WriteAsync(data, bytesWritten, size).ConfigureAwait(false);
bytesWritten += size;
lastBytesWritten = DateTime.Now;
}
Assert.Equal(data.Length, bytesWritten);
clientFinishedSendingRequestBody.TrySetResult(null);
};
var sendTask = sendFunc();
if (expectPause)
{
// The minimum is (maxRequestBufferSize - maxSendSize + 1), since if bytesWritten is
// (maxRequestBufferSize - maxSendSize) or smaller, the client should be able to
// complete another send.
var minimumExpectedBytesWritten = maxRequestBufferSize.Value - maxSendSize + 1;
// The maximum is harder to determine, since there can be OS-level buffers in both the client
// and server, which allow the client to send more than maxRequestBufferSize before getting
// paused. We assume the combined buffers are smaller than the difference between
// data.Length and maxRequestBufferSize.
var maximumExpectedBytesWritten = data.Length - 1;
// Block until the send task has gone a while without writing bytes AND
// the bytes written exceeds the minimum expected. This indicates the server buffer
// is full.
//
// If the send task is paused before the expected number of bytes have been
// written, keep waiting since the pause may have been caused by something else
// like a slow machine.
while ((DateTime.Now - lastBytesWritten) < bytesWrittenTimeout ||
bytesWritten < minimumExpectedBytesWritten)
{
await Task.Delay(bytesWrittenPollingInterval);
}
// Verify the number of bytes written before the client was paused.
Assert.InRange(bytesWritten, minimumExpectedBytesWritten, maximumExpectedBytesWritten);
// Tell server to start reading request body
startReadingRequestBody.TrySetResult(null);
// Wait for sendTask to finish sending the remaining bytes
await sendTask;
}
else
{
// Ensure all bytes can be sent before the server starts reading
await sendTask;
// Tell server to start reading request body
startReadingRequestBody.TrySetResult(null);
}
await AssertStreamContains(stream, $"bytesRead: {data.Length}");
}
await host.StopAsync();
}
await memoryPoolFactory.WhenAllBlocksReturned(TestConstants.DefaultTimeout);
}
