/*
* Trace:
* On UI thread: BEGINNING of EventHandler
* On UI thread: Beginning of GetText
* On ThreadPool thread: Called GetAsync()
* On ThreadPool thread: Called Thread.Sleep
* On ThreadPool thread: Called ReadAsStringAsync()
* On ThreadPool thread: Called Thread.Sleep again
* On UI thread: END of EventHandler
*/
private void BLOCKING_UI_CALL(object sender, EventArgs e)
{
Logger.Write("BEGINNING of EventHandler"); // on UI thread
var result = _service
.SafeMethodAsync("https://www.google.com") // on UI and ThreadPool threads
.Result; // BLOCK UI thread till the end of getting result from library method
label1.Text = result; // on UI thread
Logger.Write("END of EventHandler"); // on UI thread
}
/*
* Trace:
* On UI thread: BEGINNING of EventHandler
* On UI thread: Beginning of SafeMethodAsync
* On ThreadPool thread: Called Task.Delay (SafeMethodAsync)
* On ThreadPool thread: Called Thread.Sleep (SafeMethodAsync)
* On ThreadPool thread: End of SafeMethodAsync
* On UI thread: END of EventHandler
*/
private void BLOCKING_UI_CALL(object sender, EventArgs e)
{
Logger.Write("BEGINNING of EventHandler"); // on UI thread
Task.WaitAll(_service.SafeMethodAsync(), _task2, _task3);
Logger.Write("END of EventHandler"); // on UI thread
}
/*
* Trace:
* On UI thread: Beginning of EventHandlerMethod
* On UI thread: Beginning of SafeMethodAsync
* On ThreadPool thread: Called Task.Delay (SafeMethodAsync)
* On ThreadPool thread: Called Thread.Sleep (SafeMethodAsync)
* On ThreadPool thread: End of SafeMethodAsync
* On UI thread: End of EventHandlerMethod
*/
private void BLOCKING_OF_UI_THREAD_BUT_WITHOUT_DEADLOCK_BECAUSE_OF_ConfigureAwaitFalse_IN_THE_LIBRARY_METHOD(object sender, EventArgs e)
{
Logger.Write("Beginning of EventHandlerMethod"); // on UI thread
_service
.SafeMethodAsync() // on UI and on ThreadPool threads
.Wait(); // BLOCK UI thread till the end of execution of library method
Logger.Write("End of EventHandlerMethod"); // on UI thread
}
