public void AlreadySetSignalManuallyAwaitableWithoutExternalCaller()
{
// here we're simulating the thread-race scenario:
// thread A: checks IsCompleted, sees false
// thread B: sets the status
// thread A: asks for the awaiter and adds a continuation
var signal = new Signal();
// A
Assert.False(signal.IsCompleted);
// B
signal.Set();
int wasInvoked = 0;
// A
signal.OnCompleted(() =>
{
signal.GetResult(); // compiler awaiter always does this
Interlocked.Increment(ref wasInvoked);
});
Assert.Equal(1, Volatile.Read(ref wasInvoked));
Assert.True(signal.IsCompleted);
}
public void SignalDoesNotBecomeCompletedWhenResultFetched()
{
var signal = new Signal();
signal.Set();
signal.GetResult();
Assert.True(signal.IsCompleted);
}
public async Task AlreadySetSignalCompilerAwaitableWithoutExternalCaller()
{
var signal = new Signal();
signal.Set();
await signal;
Assert.True(signal.IsCompleted);
signal.Reset();
Assert.False(signal.IsCompleted);
}
public async Task SignalCompilerAwaitableWithExternalCaller()
{
var signal = new Signal();
ThreadPool.QueueUserWorkItem(_ =>
{
Thread.Sleep(100);
signal.Set();
});
await signal;
Assert.True(signal.IsCompleted);
}
public void ResetClearsContinuation()
{
var signal = new Signal();
bool wasInvoked = false;
signal.OnCompleted(() =>
{
signal.GetResult();
wasInvoked = true;
});
signal.Reset();
signal.Set();
Assert.False(wasInvoked);
}
public void SignalBecomesCompletedWhenSet()
{
var signal = new Signal();
signal.Set();
Assert.True(signal.IsCompleted);
}
public void CallingSetTwiceOnlyInvokesContinuationOnce()
{
var signal = new Signal();
int count = 0;
signal.OnCompleted(() => Interlocked.Increment(ref count));
signal.Set();
signal.GetResult();
signal.Set();
signal.GetResult();
Assert.Equal(1, Volatile.Read(ref count));
}
public void CallingSetTwiceHasNoBacklog()
{
var signal = new Signal();
signal.Set();
signal.Set();
Assert.True(signal.IsCompleted);
signal.GetResult();
Assert.True(signal.IsCompleted);
signal.Reset();
Assert.False(signal.IsCompleted); // only set "once"
}