public void CheckAutoFlush(int attempt)
{
const int maxAttempts = 10;
const double autoFlushSeconds = 1d;
// Don't retry if we don't have too.
if (_success)
{
Assert.True(true);
return;
}
// Detect errors on other threads.
_unhandledException = null;
ExceptionManager.UnhandledException += (source, args) =>
{
if (!args.Exception.StackTrace.Contains(@"InMemoryCache", StringComparison.OrdinalIgnoreCase))
{
return;
}
_unhandledException = args.Exception;
};
var c = new InMemoryCache <string, DisposableMock>(TimeSpan.FromSeconds(autoFlushSeconds), s =>
{
var mock = new DisposableMock
{
Id = s
};
return(mock);
}, true, false);
const string key = @"TEST";
var x1 = c[key];
Assert.Equal(key, x1.Id);
Thread.Sleep(TimeSpan.FromSeconds(autoFlushSeconds * 1.5d));
// x1 hasn't been disposed of because AutoFlush is off.
Assert.False(x1.IsDisposed);
var x2 = c[key];
// x1 will be disposed of now because it will have been cleared when the item was selected
Assert.True(x1.IsDisposed);
Assert.False(x2.IsDisposed);
Assert.NotSame(x1, x2);
// Now clear the cache and try again.
c.Flush();
c.Clear();
c.Flush();
var flushCount = 0;
c.Flushed += (a, b) => { Interlocked.Increment(ref flushCount); };
c.AutoDispose = true;
c.AutoDispose = true;
c.AutoFlush = true;
c.AutoFlush = true; // The second call should take a different path - we can check in code coverage to ensure this is the case.
Assert.True(c.AutoFlush);
flushCount = 0;
x1 = c[key];
Assert.Equal(key, x1.Id);
Assert.False(x1.IsDisposed);
var loops = 0;
const int maxLoops = 5;
Assert.Equal(c.AutoDispose, true);
Assert.Equal(c.AutoFlush, true);
// Allow multiple iterations in case there is some thread starvation.
while ((loops++ < maxLoops) && (flushCount <= 0))
{
Assert.Equal(c.AutoDispose, true);
Assert.Equal(c.AutoFlush, true);
// While we are asleep all expired members of the cache should be automatically disposed of
Thread.Sleep(TimeSpan.FromSeconds(autoFlushSeconds));
Assert.Equal(c.AutoDispose, true);
Assert.Equal(c.AutoFlush, true);
}
try
{
Assert.Null(_unhandledException);
// Now x1 has been disposed, even though it hasn't been re-fetched.
Assert.True(x1.IsDisposed, "Cached value has been disposed of.");
// There has been a flush, without us needing to do anything.
Assert.True(flushCount >= 1, "Auto-flush is responsible for disposing of the cached value.");
_success = true;
}
catch
{
if (attempt >= maxAttempts)
{
// Allow a couple of attempts because occasionally it fails for no reason.
throw;
}
}
}
