public void AfterStarted_ShouldEmitSamplesPerSecondPerWindowInOrder()
{
// Arrange
var config = GetRandom <ISystemStatsConfig>();
var logger = Substitute.For <IGenericLogger>();
var captured = new List <SamplerEventArgs <CpuUsageSampleResult[]> >();
using (var sampler = new CpuUsageSampler(config, logger))
{
// Act
sampler.OnSample += (s, a) => captured.Add(a);
sampler.Start();
Thread.Sleep(500);
// Assert
}
Expect(captured).To.Contain.At.Least(1)
.Item();
var first = captured.First();
Expect(first.Sample[0].SampleSeconds)
.To.Equal(config.ShortTermCpuWindowSeconds);
Expect(first.Sample[1].SampleSeconds)
.To.Equal(config.MediumTermCpuWindowSeconds);
Expect(first.Sample[2].SampleSeconds)
.To.Equal(config.LongTermCpuWindowSeconds);
Expect(logger.ReceivedCalls())
.To.Be.Empty();
}
public void ShouldLogErrors()
{
// Arrange
var config = GetRandom <ISystemStatsConfig>();
var logger = Substitute.For <IGenericLogger>();
using (var sampler = new CpuUsageSampler(config, logger))
{
// nefariously rip out the _totalCpu field
var fieldInfo = sampler.GetType().GetField(
"_totalCpu", BindingFlags.Instance | BindingFlags.NonPublic
);
Expect(fieldInfo).Not.To.Be.Null("Where's the _totalCpu private field?");
// Act
var gotASample = false;
sampler.OnSample += (o, e) =>
{
fieldInfo.SetValue(sampler, null);
gotASample = true;
};
sampler.Start();
while (!gotASample)
{
Thread.Sleep(100);
}
// wait for another (failed) sampling
Thread.Sleep(1200);
// Assert
Expect(logger).To.Have.Received(1)
.Log <CpuUsageSampler>(
LogType.Error,
"Error whilst attempting CPU sampling",
Arg.Any <NullReferenceException>());
}
}