public async Task MaintenanceTaskCompletesWhenPoolIsGarbageCollected()
{
var client = new SessionTestingSpannerClient();
var options = new SessionPoolOptions
{
MinimumPooledSessions = 10,
MaintenanceLoopDelay = TimeSpan.FromMinutes(1)
};
var sessionPool = new SessionPool(client, options, client.Logger);
var waitingTask = sessionPool.WaitForPoolAsync(s_sampleDatabaseName);
await client.Scheduler.RunAsync(TimeSpan.FromMinutes(5.5));
await waitingTask;
var maintenanceCount = client.Logger.GetEntries(LogLevel.Debug).Count(entry => entry.Contains("maintenance"));
Assert.InRange(maintenanceCount, 5, 6);
// Make sure the session pool is "alive" up until this point
GC.KeepAlive(sessionPool);
var weakReference = new WeakReference <SessionPool>(sessionPool);
sessionPool = null;
GC.Collect();
GC.WaitForPendingFinalizers();
// Depending on the frameowrk version and the release mode, the pool may or may not be collected
// at this point. If this weak reference has been cleared, we'll assume the internal one has been
// as well. Otherwise, this test is pointless but harmless.
if (!weakReference.TryGetTarget(out _))
{
await client.Scheduler.RunAsync(TimeSpan.FromMinutes(10));
maintenanceCount = client.Logger.GetEntries(LogLevel.Debug).Count(entry => entry.Contains("maintenance"));
// We're really just checking that at *some* point, we stopped logging.
// If the maintenance loop hadn't stopped, we'd have 15 entries.
Assert.InRange(maintenanceCount, 5, 8);
}
}
public async Task WaitForPoolAsync()
{
var client = new SessionTestingSpannerClient();
var options = new SessionPoolOptions
{
IdleSessionRefreshDelay = TimeSpan.FromMinutes(30),
PoolEvictionDelay = TimeSpan.FromMinutes(30),
MaintenanceLoopDelay = TimeSpan.FromMinutes(1),
MinimumPooledSessions = 10,
MaximumConcurrentSessionCreates = 20,
WriteSessionsFraction = 0
};
var sessionPool = new SessionPool(client, options, client.Logger);
// Ask when the pool is ready, which shouldn't take a minute.
var poolReadyTask = sessionPool.WaitForPoolAsync(s_sampleDatabaseName, default);
await client.Scheduler.RunAsync(TimeSpan.FromMinutes(1));
await poolReadyTask;
// When the pool *is* ready, we should be able to acquire a session directly from the pool,
// without any further delays.
await sessionPool.AcquireSessionAsync(s_sampleDatabaseName, new TransactionOptions(), default);
}