public static async Task <string> DoAsyncOperation(this SyncOverAsync runnable)
{
Console.WriteLine($"Entering DoAsyncOperation {Thread.CurrentThread.ManagedThreadId}");
await Task.Delay(2);
Console.WriteLine($"Finishing DoAsyncOperation {Thread.CurrentThread.ManagedThreadId}");
return("Hello");
}
public static Task WrapInContext(this SyncOverAsync runnable, Action action)
{
return(Task.Factory.StartNew(() =>
{
Console.WriteLine($"Entering SyncContext {Thread.CurrentThread.ManagedThreadId}");
action();
Console.WriteLine($"Exiting SyncContext {Thread.CurrentThread.ManagedThreadId}");
}, CancellationToken.None, TaskCreationOptions.None, scheduler));
}
public static void Explain(this SyncOverAsync runnable, TextWriter writer)
{
writer.WriteLine(@"
- `Task.Result` or `Task.Wait` on asynchronous operations is much worse than calling truly synchronous APIs. Here is what happens
- An asynchronous operation is kicked off.
- The calling thread is blocked waiting for that operation to complete.
When the asynchronous operation completes, it unblocks the code waiting on that operation. This takes place on another thread.
- This leads to thread-pool starvation and service outages due to 2 threads being used instead of 1 to complete synchronous operations.
- If a synchronization context is available it can even lead to deadlocks
");
}
public void Remove(string key) => SyncOverAsync.Run(() => RemoveAsync(key));
public void Refresh(string key) => SyncOverAsync.Run(() => RefreshAsync(key));
public byte[] Get(string key) => SyncOverAsync.Run(() => GetAsync(key));
public void Set(string key, byte[] value, DistributedCacheEntryOptions options) => SyncOverAsync.Run(() => SetAsync(key, value, options));