Files
lmxopcua/tests/Client/ZB.MOM.WW.OtOpcUa.Client.Shared.Tests/Fakes/FakeSessionFactory.cs
T
Joseph Doherty 0c9e4f4e3d fix(client): a failover abandons itself once the user disconnects or reconnects; paging and teardown minors
Review I1: ConnectAsync, DisconnectAsync and Dispose each start a new connection
epoch under _subscriptionLock. A keep-alive failover runs under the epoch it
started in and abandons itself the moment it moves: it installs its session only
if the epoch still matches (checked and assigned under the lock, otherwise the
session is disposed), its state transitions are epoch-guarded, it stops trying
endpoints, and it never flips a user's new connection to Disconnected. A late
keep-alive from a previous connection's session starts no failover. Gate-driven
tests cover the success and all-fail arms, the stale keep-alive, with a genuine
failover as the positive control (4 of them red before).

Minors: m8 only the CompareExchange winner sets LastFailover; m5 the endpoint
loop stops early, and a failed Unsubscribe still drops its bookkeeping; m1 a read
cancelled mid-paging releases its cursor (bounded token) and rethrows, and the cap
release no longer rides the caller's token; m2 results are trimmed to the cap;
m3 a non-positive cap is refused (CLI and UI already bound it to >= 1); m6 the
subscription adapter's Dispose uses one bounded bridge for delete + detach.

Refs #747
Claude-Session: https://claude.ai/code/session_01Ub9hGmYLQvn9XETzw7CMsT
2026-10-22 17:18:26 -04:00

83 lines
3.5 KiB
C#

using Opc.Ua;
using ZB.MOM.WW.OtOpcUa.Client.Shared.Adapters;
namespace ZB.MOM.WW.OtOpcUa.Client.Shared.Tests.Fakes;
internal sealed class FakeSessionFactory : ISessionFactory
{
private readonly List<FakeSessionAdapter> _createdSessions = [];
private readonly Queue<FakeSessionAdapter> _sessions = new();
/// <summary>Gets the number of times CreateSessionAsync has been called.</summary>
public int CreateCallCount { get; private set; }
/// <summary>Gets or sets a value indicating whether CreateSessionAsync should throw.</summary>
public bool ThrowOnCreate { get; set; }
/// <summary>Gets the endpoint URL from the last CreateSessionAsync call.</summary>
public string? LastEndpointUrl { get; private set; }
/// <summary>
/// Optional gate that, when set, blocks <see cref="CreateSessionAsync" /> until completed.
/// Lets tests hold a failover loop in-flight to exercise re-entrancy.
/// </summary>
public TaskCompletionSource? CreateGate { get; set; }
/// <summary>Completed when a call observes <see cref="CreateGate" />.</summary>
public TaskCompletionSource CreateEntered { get; } = new(TaskCreationOptions.RunContinuationsAsynchronously);
/// <summary>Gets the list of sessions created via CreateSessionAsync.</summary>
public IReadOnlyList<FakeSessionAdapter> CreatedSessions => _createdSessions;
/// <summary>Creates a session asynchronously (fake implementation).</summary>
/// <param name="config">The application configuration.</param>
/// <param name="endpoint">The endpoint description.</param>
/// <param name="sessionName">The session name.</param>
/// <param name="sessionTimeoutMs">The session timeout in milliseconds.</param>
/// <param name="identity">The user identity.</param>
/// <param name="ct">Cancellation token.</param>
/// <returns>A task containing the session adapter.</returns>
public async Task<ISessionAdapter> CreateSessionAsync(
ApplicationConfiguration config, EndpointDescription endpoint, string sessionName,
uint sessionTimeoutMs, UserIdentity identity, CancellationToken ct)
{
CreateCallCount++;
LastEndpointUrl = endpoint.EndpointUrl;
// One-shot: the gate holds only the call that observed it, so a later call (e.g. a user's Connect while a
// failover is held) runs freely.
if (CreateGate is { } gate)
{
CreateGate = null;
CreateEntered.TrySetResult();
await gate.Task;
}
if (ThrowOnCreate)
throw new InvalidOperationException("FakeSessionFactory configured to fail.");
FakeSessionAdapter session;
if (_sessions.Count > 0)
session = _sessions.Dequeue();
else
session = new FakeSessionAdapter
{
EndpointUrl = endpoint.EndpointUrl,
ServerName = endpoint.Server?.ApplicationName?.Text ?? "FakeServer",
SecurityMode = endpoint.SecurityMode.ToString(),
SecurityPolicyUri = endpoint.SecurityPolicyUri ?? string.Empty
};
// Ensure endpoint URL matches
session.EndpointUrl = endpoint.EndpointUrl;
_createdSessions.Add(session);
return session;
}
/// <summary>
/// Enqueues a session adapter to be returned on the next call to CreateSessionAsync.
/// </summary>
/// <param name="session">The session adapter to enqueue.</param>
public void EnqueueSession(FakeSessionAdapter session)
{
_sessions.Enqueue(session);
}
}