C# Async Programming Best Practices

Naming Conventions

• Use the 'Async' suffix for all async methods
• Match method names with their synchronous counterparts when applicable (e.g.,

  GetDataAsync()

  for

  GetData()

  )

Return Types

• Return

  Task<T>

  when the method returns a value
• Return

  Task

  when the method doesn't return a value
• Consider

  ValueTask<T>

  for high-performance scenarios to reduce allocations
• Avoid returning

  void

  for async methods except for event handlers

Exception Handling

• Use try/catch blocks around await expressions
• Avoid swallowing exceptions in async methods
• Use

  ConfigureAwait(false)

  when appropriate to prevent deadlocks in library code
• Propagate exceptions with

  Task.FromException()

  instead of throwing in async Task returning methods

Performance

• Use

  Task.WhenAll()

  for parallel execution of multiple tasks
• Use

  Task.WhenAny()

  for implementing timeouts or taking the first completed task
• Avoid unnecessary async/await when simply passing through task results
• Consider cancellation tokens for long-running operations

Common Pitfalls

• Never use

  .Wait()

  ,

  .Result

  , or

  .GetAwaiter().GetResult()

  in async code
• Avoid mixing blocking and async code
• Don't create async void methods (except for event handlers)
• Always await Task-returning methods

Implementation Patterns

• Implement the async command pattern for long-running operations
• Use async streams (IAsyncEnumerable<T>) for processing sequences asynchronously
• Consider the task-based asynchronous pattern (TAP) for public APIs