private static Task <int> ReturnValueAsyncWithoutAssistance()
{
AsyncTaskMethodBuilder <int> builder = AsyncTaskMethodBuilder <int> .Create();
try
{
Task <int> task = Task <int> .Factory.StartNew(() => 5);
TaskAwaiter <int> awaiter = task.GetAwaiter();
if (!awaiter.IsCompleted)
{
// Result wasn't available. Add a continuation, and return the builder.
// We really want: awaiter.OnCompleted(goto afterAwait);
awaiter.OnCompleted(() =>
{
try
{
int tmp2 = awaiter.GetResult();
builder.SetResult(tmp2 + 1);
}
catch (Exception e)
{
builder.SetException(e);
}
});
return(builder.Task);
}
// Result was already available: proceed synchronously
afterAwait:
int tmp = awaiter.GetResult();
builder.SetResult(tmp + 1);
}
catch (Exception e)
{
builder.SetException(e);
}
return(builder.Task);
}
public void MoveNext()
{
int result;
try
{
#pragma warning disable 0219 // doFinallyBodies is never used
bool doFinallyBodies = true;
#pragma warning restore
if (state != 1)
{
if (state != -1)
{
task = Task <int> .Factory.StartNew(() => 5);
awaiter = task.GetAwaiter();
if (awaiter.IsCompleted)
{
goto Label_GetResult;
}
state = 1;
doFinallyBodies = false;
awaiter.OnCompleted(moveNextDelegate);
}
return;
}
state = 0;
Label_GetResult: // target of state=1
int awaitResult = awaiter.GetResult();
awaiter = default(TaskAwaiter <int>);
result = awaitResult;
}
catch (Exception e)
{
state = -1;
builder.SetException(e);
return;
}
state = -1;
builder.SetResult(result);
}
public void MoveNext()
{
int result;
try
{
bool doFinallyBodies = true;
int tmpState = state;
// Effectively a three way switch: 1, -1, 0
if (tmpState != 1)
{
if (state == -1)
{
return;
}
this.writer = File.CreateText("output.txt");
}
try
{
tmpState = state;
if (tmpState == 1)
{
goto Label_ResumePoint;
}
sum = 0;
i = 0;
Label_ResumePoint: // This shouldn't quite be here... see below
while (i < loopCount)
{
// Not in generated code:
if (state == 1)
{
goto Label_ResumePoint2;
}
// Back to generated code
valueFetcher = Task.Factory.StartNew(() => 1);
j = 0;
// Still not in the generated code, and still not quite right... we don't want the j test here
Label_ResumePoint2:
// Back to generated code again...
while (j < 3)
{
try
{
// We want Label_ResumePoint to be here really
tmpState = state;
if (tmpState != 1)
{
Console.WriteLine("Awaiting...");
awaiter = valueFetcher.GetAwaiter();
if (!awaiter.IsCompleted)
{
state = 1;
doFinallyBodies = false;
awaiter.OnCompleted(moveNextDelegate);
return;
}
}
else
{
state = 0;
}
int awaitResult = awaiter.GetResult();
awaiter = new TaskAwaiter <int>();
value = awaitResult;
writer.WriteLine("Got value {0}", value);
sum += value;
break;
}
catch (Exception)
{
Console.WriteLine("Oops... retrying");
}
j++;
}
i++;
}
result = sum;
}
finally
{
if (doFinallyBodies && writer != null)
{
writer.Dispose();
}
}
}
catch (Exception e)
{
state = -1;
builder.SetException(e);
return;
}
state = -1;
builder.SetResult(result);
}
public void MoveNext()
{
int result;
try
{
int awaitResult1 = 0;
int awaitResult2 = 0;
int awaitResult3 = 0;
#pragma warning disable 0219 // doFinallyBodies is never used
bool doFinallyBodies = true;
#pragma warning restore
switch (state)
{
case 1:
break;
case 2:
goto Label_Awaiter2Continuation;
case 3:
goto Label_Awaiter3Continuation;
default:
if (state != -1)
{
task1 = Task.Factory.StartNew(() => 1);
task2 = Task.Factory.StartNew(() => 2);
task3 = Task.Factory.StartNew(() => 3);
awaiter1 = task1.GetAwaiter();
if (awaiter1.IsCompleted)
{
goto Label_GetAwaiter1Result;
}
state = 1;
doFinallyBodies = false;
awaiter1.OnCompleted(moveNextDelegate);
}
return;
}
state = 0;
Label_GetAwaiter1Result:
awaitResult1 = awaiter1.GetResult();
awaiter1 = new TaskAwaiter <int>();
awaiter2 = task2.GetAwaiter();
if (awaiter2.IsCompleted)
{
goto Label_GetAwaiter2Result;
}
state = 2;
doFinallyBodies = false;
awaiter2.OnCompleted(moveNextDelegate);
return;
Label_Awaiter2Continuation:
state = 0;
Label_GetAwaiter2Result:
awaitResult2 = awaiter2.GetResult();
awaiter2 = new TaskAwaiter <int>();
awaiter3 = task3.GetAwaiter();
if (awaiter3.IsCompleted)
{
goto Label_GetAwaiter3Result;
}
state = 3;
doFinallyBodies = false;
awaiter3.OnCompleted(moveNextDelegate);
return;
Label_Awaiter3Continuation:
state = 0;
Label_GetAwaiter3Result:
awaitResult3 = awaiter3.GetResult();
awaiter3 = new TaskAwaiter <int>();
result = awaitResult1 + awaitResult2 + awaitResult3;
}
catch (Exception e)
{
state = -1;
builder.SetException(e);
return;
}
state = -1;
builder.SetResult(result);
}