public void TestEquality()
{
var connectionA = new ZooKeeperConnectionInfo(
"cs",
TimeSpan.FromSeconds(1),
TimeSpan.FromSeconds(2),
new EquatableReadOnlyList <ZooKeeperAuthInfo>(new[] { new ZooKeeperAuthInfo("s", new EquatableReadOnlyList <byte>(new byte[] { 10 })) })
);
var connectionB = new ZooKeeperConnectionInfo(
"cs",
TimeSpan.FromSeconds(1),
TimeSpan.FromSeconds(2),
new EquatableReadOnlyList <ZooKeeperAuthInfo>(new[] { new ZooKeeperAuthInfo("s", new EquatableReadOnlyList <byte>(new byte[] { 10 })) })
);
var connectionC = connectionA with {
AuthInfo = new EquatableReadOnlyList <ZooKeeperAuthInfo>(new[]
{
new ZooKeeperAuthInfo("s", new EquatableReadOnlyList <byte>(new byte[] { 10 })),
new ZooKeeperAuthInfo("s2", new EquatableReadOnlyList <byte>(new byte[] { 11 })),
})
};
Assert.IsTrue(connectionA == connectionB);
connectionA.GetHashCode().ShouldEqual(connectionB.GetHashCode());
Assert.IsFalse(connectionA == connectionC);
Assert.AreNotEqual(connectionA.GetHashCode(), connectionC.GetHashCode());
}
}
private void ReleaseEntry(ZooKeeperConnectionInfo connectionInfo, ConnectionEntry entry, bool remove)
{
bool shouldDispose;
lock (this.PoolLock)
{
if (remove)
{
this.Connections.As <ICollection <KeyValuePair <ZooKeeperConnectionInfo, ConnectionEntry> > >()
.Remove(new KeyValuePair <ZooKeeperConnectionInfo, ConnectionEntry>(connectionInfo, entry));
}
shouldDispose = --entry.UserCount == 0;
// this guarantee is upheld by the fact that we include the timeout watcher task as a "user"
Invariant.Require(
!shouldDispose || !(this.Connections.TryGetValue(connectionInfo, out var registeredEntry) && registeredEntry == entry),
"If we're disposing then the entry must be removed from the pool"
);
}
if (shouldDispose)
{
// kick off connection disposal in the background to
// avoid blocking/throwing and to handle the case where the task hasn't yet completed
entry.ConnectionTask.ContinueWith(
t => { var ignored = t.Result.DisposeAsync(); },
TaskContinuationOptions.OnlyOnRanToCompletion
);
}
}
private async Task <InternalConnection> InternalConnectAsync(ZooKeeperConnectionInfo connectionInfo)
{
var watcher = new ConnectionWatcher(connectionInfo.SessionTimeout);
var zooKeeper = new ZooKeeper(
connectstring: connectionInfo.ConnectionString,
sessionTimeout: connectionInfo.SessionTimeout.InMilliseconds,
watcher: watcher
);
using var timeoutSource = new CancellationTokenSource(connectionInfo.ConnectTimeout.TimeSpan);
using var timeoutRegistration = timeoutSource.Token.Register(
() => watcher.TaskCompletionSource.TrySetException(new TimeoutException($"Timed out connecting to ZooKeeper after {connectionInfo.ConnectTimeout.InMilliseconds}ms"))
);
foreach (var authInfo in connectionInfo.AuthInfo)
{
zooKeeper.addAuthInfo(authInfo.Scheme, authInfo.Auth.ToArray());
}
try
{
await watcher.TaskCompletionSource.Task.ConfigureAwait(false);
return(new InternalConnection(zooKeeper, watcher));
}
catch
{
// on failure, clean up the instance we created
try { await zooKeeper.closeAsync().ConfigureAwait(false); }
finally { watcher.Dispose(); }
throw;
}
}
public Task <ZooKeeperConnection> ConnectAsync(ZooKeeperConnectionInfo connectionInfo, CancellationToken cancellationToken)
{
cancellationToken.ThrowIfCancellationRequested();
lock (this.PoolLock)
{
// if we have an entry in the pool, use that
if (this.Connections.TryGetValue(connectionInfo, out var entry))
{
++entry.UserCount;
return(ToResultAsync(entry));
}
// create a new connection
var newConnectionTask = this.InternalConnectAsync(connectionInfo);
var newEntry = new ConnectionEntry(newConnectionTask)
{
// 2 because we have both the current request and the timeout task we're about to create
UserCount = 2
};
this.Connections.Add(connectionInfo, newEntry);
newConnectionTask.ContinueWith(OnConnectionTaskCompleted);
return(ToResultAsync(newEntry));
void OnConnectionTaskCompleted(Task <InternalConnection> internalConnectionTask)
{
// if we never connected, just release our hold on the task
if (internalConnectionTask.Status != TaskStatus.RanToCompletion)
{
this.ReleaseEntry(connectionInfo, newEntry, remove: true);
}
// Otherwise, wait until either max age has elapsed or the connection is lost to release our hold. This
// ensures both that the connection won't be removed from the pool prematurely as well as that it will be
// eventually removed even if it stops being used
else
{
Task.Delay(this._maxAge.TimeSpan, internalConnectionTask.Result.ConnectionLostToken)
.ContinueWith(_ => this.ReleaseEntry(connectionInfo, newEntry, remove: true));
}
}
}
async Task <ZooKeeperConnection> ToResultAsync(ConnectionEntry entry)
{
try
{
var internalConnection = await entry.ConnectionTask.ConfigureAwait(false);
return(new ZooKeeperConnection(internalConnection, releaseToPool: () => this.ReleaseEntry(connectionInfo, entry, remove: false)));
}
catch
{
// if we fail to construct a connection, still release our hold on the entry to allow cleanup
this.ReleaseEntry(connectionInfo, entry, remove: false);
throw;
}
}
}
public ZooKeeperSynchronizationHelper(
ZooKeeperPath path,
bool assumePathExists,
string connectionString,
Action <ZooKeeperDistributedSynchronizationOptionsBuilder>?optionsBuilder,
bool setAcquiredMarker = false)
{
this.Path = path;
this._assumePathExists = assumePathExists;
var options = ZooKeeperDistributedSynchronizationOptionsBuilder.GetOptions(optionsBuilder);
this._connectionInfo = new ZooKeeperConnectionInfo(
connectionString ?? throw new ArgumentNullException(nameof(connectionString)),
ConnectTimeout: options.ConnectTimeout,
SessionTimeout: options.SessionTimeout,
AuthInfo: options.AuthInfo
);
this._acl = options.Acl;
this._setAcquiredMarker = setAcquiredMarker;
}