public void OperationTracker_Basics1()
{
var o = new OperationTracker();
//
// Enter a few times.
//
var g1 = o.Enter();
var g2 = o.Enter();
//
// Double-dispose is fine.
//
g1.Dispose();
g1.Dispose();
//
// Initiate dispose.
//
var d = o.DisposeAsync()
#if NET5_0 || NETCOREAPP3_1
.AsTask()
#endif
;
Assert.IsFalse(d.IsCompleted);
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
//
// Exit the last operation.
//
g2.Dispose();
//
// Tracker is disposed now.
//
d.Wait();
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
}
public void OperationTracker_Basics2()
{
var o = new OperationTracker();
//
// Enter a few times.
//
var g1 = o.Enter();
var g2 = o.Enter();
//
// Initiate dispose a first time.
//
var d1 = o.DisposeAsync()
#if NET5_0 || NETCOREAPP3_1
.AsTask()
#endif
;
Assert.IsFalse(d1.IsCompleted);
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
//
// Initiate dispose a second time.
//
var d2 = o.DisposeAsync()
#if NET5_0 || NETCOREAPP3_1
.AsTask()
#endif
;
Assert.IsFalse(d2.IsCompleted);
//
// Exit one of the operations.
//
g2.Dispose();
Assert.IsFalse(d1.IsCompleted);
Assert.IsFalse(d2.IsCompleted);
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
//
// Exit the other operation.
//
g1.Dispose();
//
// Tracker is disposed now.
//
d1.Wait();
d2.Wait();
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
//
// Dispose is a no-op now.
//
o.DisposeAsync()
#if NET5_0 || NETCOREAPP3_1
.AsTask()
#endif
.Wait();
//
// Cannot enter again.
//
Assert.ThrowsException <ObjectDisposedException>(() => o.Enter());
}
public void OperationTracker_Concurrent()
{
//
// Create enough competing threads so we have concurrency the moment we dispose the tracker.
//
int n = Environment.ProcessorCount * 4;
using var c = new CountdownEvent(n);
using var e = new ManualResetEvent(initialState: false);
var tasks = new Thread[n];
var t = new OperationTracker();
//
// Each thread will enter, then signal having arrived within the tracked scope, and then wait for a signal to continue.
//
for (int i = 0; i < n; i++)
{
var u = new Thread(() =>
{
using var _ = t.Enter();
c.Signal();
e.WaitOne();
Thread.Yield();
});
tasks[i] = u;
u.Start();
}
//
// Wait for all threads to arrive, then let them loose.
//
c.Wait();
e.Set();
//
// Initiate and await completion of closing the tracker.
//
t.DisposeAsync()
#if NET5_0 || NETCOREAPP3_1
.AsTask()
#endif
.Wait();
//
// Join all threads.
//
foreach (var u in tasks)
{
u.Join();
}
}
