public void First_call_to_meter_returns_zero()
{
using (var meter = new ProcessCpuUsageMeter())
{
var usage = meter.GetCpuUsage();
usage.Should().Be(0);
}
}
public void Value_is_cached_for_next_250_milliseconds()
{
var cachePeriod = 250.Milliseconds();
using (var meter = new ProcessCpuUsageMeter())
{
// warmup meter
TestHelpers.GetMeterValues(() => meter.GetCpuUsage(), cachePeriod, 2);
var results = TestHelpers.GetMeterValues(
() => meter.GetCpuUsage(),
((cachePeriod - 20.Milliseconds()).Ticks / 5).Ticks(),
5);
results.Should().AllBeEquivalentTo(results[0]);
}
}
public void Measures_CPU_usage_for_process() //TODO (epeshk): should we set limits or use processor affinity to make this test more stable?
{
using (var testProcess = new TestProcessHandle())
using (var meter = new ProcessCpuUsageMeter(testProcess.Process.Id))
{
var observationsCount = 20;
var lowValues = TestHelpers.GetMeterValues(() => meter.GetCpuUsage(), TimeSpan.FromMilliseconds(100), observationsCount);
testProcess.EatCpu(1);
var highValues = TestHelpers.GetMeterValues(() => meter.GetCpuUsage(), TimeSpan.FromMilliseconds(100), observationsCount);
Console.WriteLine($"Low values: {string.Join(", ", lowValues)}");
Console.WriteLine($"High values: {string.Join(", ", highValues)}");
highValues
.Count(h => lowValues.All(l => l < h))
.Should()
.BeGreaterOrEqualTo((int)(highValues.Length * 0.75));
}
}
