private static async Task WaitWithConnectionCancellationAsync(ValueTask task, HttpConnection connection, CancellationToken cancellationToken)
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
await task.ConfigureAwait(false);
}
finally
{
ctr.Dispose();
}
}
public override async ValueTask <int> ReadAsync(Memory <byte> buffer, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
HttpConnection connection = _connection;
if (connection == null || buffer.Length == 0)
{
// Response body fully consumed or the caller didn't ask for any data
return(0);
}
ValueTask <int> readTask = connection.ReadBufferedAsync(buffer);
int bytesRead;
if (readTask.IsCompletedSuccessfully)
{
bytesRead = readTask.Result;
}
else
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
bytesRead = await readTask.ConfigureAwait(false);
}
finally
{
ctr.Dispose();
}
}
if (bytesRead == 0)
{
// A cancellation request may have caused the EOF.
cancellationToken.ThrowIfCancellationRequested();
// We cannot reuse this connection, so close it.
_connection = null;
connection.Dispose();
}
return(bytesRead);
}
private async Task CompleteCopyToAsync(Task copyTask, HttpConnection connection, CancellationToken cancellationToken)
{
CancellationTokenRegistration ctr = connection.RegisterCancellation(cancellationToken);
try
{
await copyTask.ConfigureAwait(false);
}
finally
{
ctr.Dispose();
}
// If cancellation is requested and tears down the connection, it could cause the copy
// to end early but think it ended successfully. So we prioritize cancellation in this
// race condition, and if we find after the copy has completed that cancellation has
// been requested, we assume the copy completed due to cancellation and throw.
cancellationToken.ThrowIfCancellationRequested();
Finish(connection);
}