public RoundBasedRegister(IIntercomMessageHub intercomMessageHub,
IBallotGenerator ballotGenerator,
ISynodConfigurationProvider synodConfigProvider,
LeaseConfiguration leaseConfig,
ILogger logger)
{
this.logger = logger;
this.synodConfigProvider = synodConfigProvider;
this.leaseConfig = leaseConfig;
this.intercomMessageHub = intercomMessageHub;
readBallot = ballotGenerator.Null();
writeBallot = ballotGenerator.Null();
listener = intercomMessageHub.Subscribe();
listener.Where(m => m.Equals(ConsensusMessages.LeaseRead)).Subscribe(OnReadReceived);
listener.Where(m => m.Equals(ConsensusMessages.LeaseWrite)).Subscribe(OnWriteReceived);
ackReadStream = listener.Where(m => m.Equals(ConsensusMessages.LeaseAckRead));
nackReadStream = listener.Where(m => m.Equals(ConsensusMessages.LeaseNackRead));
ackWriteStream = listener.Where(m => m.Equals(ConsensusMessages.LeaseAckWrite));
nackWriteStream = listener.Where(m => m.Equals(ConsensusMessages.LeaseNackWrite));
WaitBeforeNextLeaseIssued(leaseConfig);
}
public BallotGenerator(LeaseConfiguration config)
{
this.config = config;
lastBallotTimestamp = new BallotTimestamp {
MessageNumber = 0, Timestamp = DateTime.UtcNow
};
}
public void TwoBallotsGeneratedWithinSafetyPeriod_HaveDifferentMessageNumber()
{
var identity = new byte[] { 0 };
var leaseConfig = new LeaseConfiguration
{
ClockDrift = TimeSpan.FromMilliseconds(500)
};
var ballotGenerator = new BallotGenerator(leaseConfig);
var ballot1 = ballotGenerator.New(identity);
Thread.Sleep((int)leaseConfig.ClockDrift.TotalMilliseconds / 10);
var ballot2 = ballotGenerator.New(identity);
Assert.GreaterOrEqual(leaseConfig.ClockDrift, ballot2.Timestamp - ballot1.Timestamp);
Assert.AreNotEqual(ballot1.MessageNumber, ballot2.MessageNumber);
}
public LeaseProvider(IRoundBasedRegister register,
IBallotGenerator ballotGenerator,
LeaseConfiguration config,
ISynodConfigurationProvider synodConfigProvider,
ILogger logger)
{
ValidateConfiguration(config);
localNode = synodConfigProvider.LocalNode;
this.logger = logger;
this.config = config;
this.ballotGenerator = ballotGenerator;
this.register = register;
leaseRenewWaitTimeout = TimeSpan.FromMilliseconds(10);
renewGateway = new SemaphoreSlim(1);
leaseTimer = new Timer(state => ScheduledReadOrRenewLease(), null, TimeSpan.FromMilliseconds(-1), TimeSpan.FromMilliseconds(-1));
}
private void ValidateConfiguration(LeaseConfiguration config)
{
if (config.NodeResponseTimeout.TotalMilliseconds * 2 > config.MessageRoundtrip.TotalMilliseconds)
{
throw new Exception($"{nameof(config.NodeResponseTimeout)}[{config.NodeResponseTimeout.TotalMilliseconds} msec] " +
"should be at least 2 times shorter than " +
$"{nameof(config.MessageRoundtrip)}[{config.MessageRoundtrip.TotalMilliseconds} msec]");
}
if (config.MaxLeaseTimeSpan
- config.MessageRoundtrip.MultiplyBy(2)
- config.ClockDrift <= TimeSpan.Zero)
{
throw new Exception($"{nameof(config.MaxLeaseTimeSpan)}[{config.MaxLeaseTimeSpan.TotalMilliseconds} msec] " +
"should be longer than " +
$"(2 * {nameof(config.MessageRoundtrip)}[{config.MessageRoundtrip.TotalMilliseconds} msec] " +
$"+ {nameof(config.ClockDrift)}[{config.ClockDrift.TotalMilliseconds} msec])");
}
}
private void WaitBeforeNextLeaseIssued(LeaseConfiguration config) => Task.Delay(config.ClockDrift).ContinueWith(_ => StartIntercomMessageHub());