public void DoNotClaimExternalResourcesIfThePoolIsNotEmpty()
{
var pool = new SlowProviderPool(4);
//this call will claim an external resource
pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 1);
//this one too
var res2 = pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 2);
//now we put a resource back to the pool
pool.Put(res2);
//this call should be served with the pooled resource
var res3 = pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 2);
//invalidate a resource and put it back to the pool
res3.IsValid = false;
pool.Put(res3);
//this call will claim an external resource as the one available in the pool is
//not valid any more
pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 3);
//the pool should be empty now
Assert.AreEqual(pool.ResourcesInPool, 0);
}
public void DoNotClaimUnlimitedNewResources()
{
var pool = new SlowProviderPool(4);
long count = 0;
for (var i = 0; i < 10; i++)
{
ThreadPool.QueueUserWorkItem(delegate
{
var res = pool.Get();
Thread.Sleep(50);
pool.Put(res);
Interlocked.Increment(ref count);
});
}
while (Interlocked.Read(ref count) < 10)
{
Thread.Sleep(10);
}
var claimCount = pool.NewResourceClaims;
//as consumer threads are much faster than the resource provider, most of the connections
//are recicled ones not new ones
Assert.IsTrue(claimCount < 100);
}
public void PreloadedResourcePool()
{
var pool = new SlowProviderPool(4, 3);
Assert.AreEqual(pool.NewResourceClaims, 3);
Assert.AreEqual(pool.ResourcesInPool, 3);
//three requests should be served by the pool without claiming external resource
var res1 = pool.Get();
var res2 = pool.Get();
var res3 = pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 3);
//this one is claimed from outside
var res4 = pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 4);
//this one too
var res5 = pool.Get();
Assert.AreEqual(pool.NewResourceClaims, 5);
//put back 5 resorces ( the first one should be released as capacity is exceeded)
pool.Put(res1);
pool.Put(res2);
pool.Put(res3);
pool.Put(res4);
pool.Put(res5);
Assert.AreEqual(pool.ResourcesInPool, 4);
//res1 was relesed, the next returned one should be res2
var res2Again = pool.Get();
Assert.AreSame(res2, res2Again);
}