AArnott

public void DoSomething()
{
  DoSomethingAsync().Wait(); // WARNING: this will deadlock. Don’t do this.
}

public async Task DoSomethingAsync()
{
  await Task.Yield(); // could be any async work
}

AArnott

private int m_filesOpened;
private const int MaxOpenFilesAllowed = 2;
private FileStream[] m_openFiles = new FileStream[MaxOpenFilesAllowed];
public int SomeMethod(string path)
{
  ThreadHelper.ThrowIfNotOnUIThread();
  if (m_filesOpened < MaxOpenFilesAllowed)
  {
    m_openFiles[m_filesOpened] = File.Open(path, FileMode.Open);
    m_filesOpened++;

AArnott

private async Task PerformDataAnalysisAsync()
{
  // At this point, we’re on whatever thread the caller was on (UI thread or background).
  // The first thing we do is call a VS service, so ensure we’re on the UI thread.
  await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
  this.solution.EnumProjects(…);
  await DoSomethingAsync();
  // We’re still on the UI thread at this point.
  // Let’s get off to do some expensive work without disturbing the user.
  await TaskScheduler.Default;

AArnott

ThreadHelper.JoinableTaskFactory.Run(async delegate
{
  await SomeOperationAsync();
});

AArnott

int result = ThreadHelper.JoinableTaskFactory.Run(async delegate
{
  int value = await SomeOperationAsync();
  return value;
});
return result;

AArnott

public IVsTask CreateProjectAsync(string projectName)
{
  return ThreadHelper.JoinableTaskFactory.RunAsyncAsVsTask(
    VsTaskRunContext.UIThreadBackgroundPriority,
    async cancellationToken =>
    {
      // Code here executes on the caller's thread (UI thread or otherwise)
      // before CreateProjectAsync returns an IVsTask.
      // [ your synchronous portion here ]

AArnott

public IVsTask CreateProjectAsync(string projectName)
{
  return ThreadHelper.JoinableTaskFactory.RunAsyncAsVsTask(
    VsTaskRunContext.UIThreadBackgroundPriority,
    async cancellationToken =>
    {
      IVsAsyncService someService;
      IVsTask someOtherAsyncOperation = someService.SomethingAsync();
      await someOtherAsyncOperation;

AArnott

public IVsTask CreateProjectAsync(string projectName)
{
  return ThreadHelper.JoinableTaskFactory.RunAsyncAsVsTask(
    VsTaskRunContext.UIThreadBackgroundPriority,
    async cancellationToken =>
    {
      await Task.Yield();

      return VSConstants.S_OK;
    });

AArnott

await joinableTaskFactoryInstance.SwitchToMainThreadAsync();

AArnott

JoinableTaskFactory.Run(async delegate {
  await SomeOperationAsync(...);
});