Apr 22, 2025 · Apr 17, 2025
diff --git a/Tests.Vpn.Service/DownloaderTest.cs b/Tests.Vpn.Service/DownloaderTest.cs
        Assert.That(ex.Message, Does.Contain("ETag does not match SHA1 hash of downloaded file").And.Contains("beef"));
    }

    [Test(Description = "Timeout waiting for existing download")]
    [CancelAfter(30_000)]
    public async Task CancelledWaitingForOther(CancellationToken ct)
    {
        var testCts = CancellationTokenSource.CreateLinkedTokenSource(ct);
        using var httpServer = new TestHttpServer(async _ =>
        {
            await Task.Delay(TimeSpan.FromSeconds(5), testCts.Token);
        });
        var url0 = new Uri(httpServer.BaseUrl + "/test0");
        var url1 = new Uri(httpServer.BaseUrl + "/test1");
        var destPath = Path.Combine(_tempDir, "test");
        var manager = new Downloader(NullLogger<Downloader>.Instance);

        // first outer task succeeds, getting download started
        var dlTask0 = await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url0), destPath,
            NullDownloadValidator.Instance, testCts.Token);

        // The second request fails if the timeout is short
        var smallerCt = new CancellationTokenSource(TimeSpan.FromSeconds(1)).Token;
        Assert.ThrowsAsync<TaskCanceledException>(async () => await manager.StartDownloadAsync(
            new HttpRequestMessage(HttpMethod.Get, url1), destPath,
            NullDownloadValidator.Instance, smallerCt));
        await testCts.CancelAsync();
    }

    [Test(Description = "Timeout on response body")]
    [CancelAfter(30_000)]
    public async Task CancelledInner(CancellationToken ct)
diff --git a/Vpn.Service/Downloader.cs b/Vpn.Service/Downloader.cs
    {
        while (true)
        {
            ct.ThrowIfCancellationRequested();
            var task = _downloads.GetOrAdd(destinationPath,
                _ => new DownloadTask(_logger, req, destinationPath, validator));
            // EnsureStarted is a no-op if we didn't create a new DownloadTask.
            _logger.LogWarning(
                "Download for '{DestinationPath}' is already in progress, but is for a different Url - awaiting completion",
                destinationPath);
            await task.Task;
            await TaskOrCancellation(task.Task, ct);
        }
    }

    /// <summary>
    /// TaskOrCancellation waits for either the task to complete, or the given token to be canceled.
    /// </summary>
    internal static async Task TaskOrCancellation(Task task, CancellationToken cancellationToken)
    {
        var cancellationTask = new TaskCompletionSource();
        await using (cancellationToken.Register(() => cancellationTask.TrySetCanceled()))
        {
            // Wait for either the task or the cancellation
            var completedTask = await Task.WhenAny(task, cancellationTask.Task);
            // Await to propagate exceptions, if any
            await completedTask;
        }
    }
 }
Original file line number	Diff line number	Diff line change
Expand Up		@@ -412,6 +412,32 @@ public async Task MismatchedETag(CancellationToken ct)
		Assert.That(ex.Message, Does.Contain("ETag does not match SHA1 hash of downloaded file").And.Contains("beef"));
		}

		[Test(Description = "Timeout waiting for existing download")]
		[CancelAfter(30_000)]
		public async Task CancelledWaitingForOther(CancellationToken ct)
		{
		var testCts = CancellationTokenSource.CreateLinkedTokenSource(ct);
		using var httpServer = new TestHttpServer(async _ =>
		{
		await Task.Delay(TimeSpan.FromSeconds(5), testCts.Token);
		});
		var url0 = new Uri(httpServer.BaseUrl + "/test0");
		var url1 = new Uri(httpServer.BaseUrl + "/test1");
		var destPath = Path.Combine(_tempDir, "test");
		var manager = new Downloader(NullLogger<Downloader>.Instance);

		// first outer task succeeds, getting download started
		var dlTask0 = await manager.StartDownloadAsync(new HttpRequestMessage(HttpMethod.Get, url0), destPath,
		NullDownloadValidator.Instance, testCts.Token);

		// The second request fails if the timeout is short
		var smallerCt = new CancellationTokenSource(TimeSpan.FromSeconds(1)).Token;
		Assert.ThrowsAsync<TaskCanceledException>(async () => await manager.StartDownloadAsync(
		new HttpRequestMessage(HttpMethod.Get, url1), destPath,
		NullDownloadValidator.Instance, smallerCt));
		await testCts.CancelAsync();
		}

		[Test(Description = "Timeout on response body")]
		[CancelAfter(30_000)]
		public async Task CancelledInner(CancellationToken ct)
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Original file line number	Diff line number	Diff line change
Expand Up		@@ -287,6 +287,7 @@ public async Task<DownloadTask> StartDownloadAsync(HttpRequestMessage req, strin
		{
		while (true)
		{
		ct.ThrowIfCancellationRequested();
		var task = _downloads.GetOrAdd(destinationPath,
		_ => new DownloadTask(_logger, req, destinationPath, validator));
		// EnsureStarted is a no-op if we didn't create a new DownloadTask.
Expand DownExpand Up		@@ -322,7 +323,22 @@ public async Task<DownloadTask> StartDownloadAsync(HttpRequestMessage req, strin
		_logger.LogWarning(
		"Download for '{DestinationPath}' is already in progress, but is for a different Url - awaiting completion",
		destinationPath);
		await task.Task;
		await TaskOrCancellation(task.Task, ct);
		}
		}

		/// <summary>
		/// TaskOrCancellation waits for either the task to complete, or the given token to be canceled.
		/// </summary>
		internal static async Task TaskOrCancellation(Task task, CancellationToken cancellationToken)
		{
		var cancellationTask = new TaskCompletionSource();
		await using (cancellationToken.Register(() => cancellationTask.TrySetCanceled()))
		{
		// Wait for either the task or the cancellation
		var completedTask = await Task.WhenAny(task, cancellationTask.Task);
		// Await to propagate exceptions, if any
		await completedTask;
		}
		}
		}
Expand Down