/// <summary>
/// Handles a request from a remote node.
/// </summary>
/// <param name="node">The ID of the remote node.</param>
/// <param name="request">The <see cref="SdkResolverRequest"/> containing information about the SDK to resolve.</param>
/// <remarks>This method must not directly handle requests because it would block requests from other nodes. Instead, it simply
/// adds requests to a queue which are processed by a background thread.</remarks>
private void HandleRequest(int node, SdkResolverRequest request)
{
if (_requestHandler == null)
{
// Start the background thread which will process queued requests if it has not already been started.
lock (_lockObject)
{
if (_requestHandler == null)
{
// Create the event used to signal that a request was received
_requestReceivedEvent = new ManualResetEvent(initialState: false);
// Create the queue used to store requests that need to be processed
_requests = new ConcurrentQueue <SdkResolverRequest>();
// Create the thread which processes requests
_requestHandler = Task.Factory.StartNew(RequestHandlerPumpProc, TaskCreationOptions.LongRunning);
}
}
}
// Associate the node with the request
request.NodeId = node;
_requests.Enqueue(request);
// Signal that one or more requests have been received
_requestReceivedEvent.Set();
}
/// <summary>
/// Processes all requests that are currently in the queue.
/// </summary>
private void ProcessRequests()
{
// Store a list of threads which are resolving SDKs
List <Task> tasks = new List <Task>(_requests.Count);
SdkResolverRequest item;
while (_requests.TryDequeue(out item))
{
SdkResolverRequest request = item;
// Start a thread to resolve an SDK and add it to the list of threads
tasks.Add(Task.Run(() =>
{
SdkResult response = null;
try
{
// Create an SdkReference from the request
SdkReference sdkReference = new SdkReference(request.Name, request.Version, request.MinimumVersion);
ILoggingService loggingService = Host.GetComponent(BuildComponentType.LoggingService) as ILoggingService;
// This call is usually cached so is very fast but can take longer for a new SDK that is downloaded. Other queued threads for different SDKs will complete sooner and continue on which unblocks evaluations
response = ResolveSdk
(
request.SubmissionId,
sdkReference,
new EvaluationLoggingContext(loggingService, request.BuildEventContext, request.ProjectPath),
request.ElementLocation,
new SdkEnv(request.SolutionPath, request.ProjectPath),
request.Interactive
);
}
catch (Exception e)
{
ILoggingService loggingService = Host.GetComponent(BuildComponentType.LoggingService) as ILoggingService;
EvaluationLoggingContext loggingContext = new EvaluationLoggingContext(loggingService, request.BuildEventContext, request.ProjectPath);
loggingService.LogFatalBuildError(loggingContext.BuildEventContext, e, new BuildEventFileInfo(request.ElementLocation));
}
finally
{
// Get the node manager and send the response back to the node that requested the SDK
INodeManager nodeManager = Host.GetComponent(BuildComponentType.NodeManager) as INodeManager;
nodeManager.SendData(request.NodeId, response);
}
}));
}
// Wait for all tasks to complete
Task.WaitAll(tasks.ToArray());
}
private SdkResult RequestSdkPathFromMainNode(int submissionId, SdkReference sdk, LoggingContext loggingContext, ElementLocation sdkReferenceLocation, string solutionPath, string projectPath, bool interactive)
{
// Clear out the last response for good measure
_lastResponse = null;
// Create the SdkResolverRequest packet to send
INodePacket packet = SdkResolverRequest.Create(submissionId, sdk, loggingContext.BuildEventContext, sdkReferenceLocation, solutionPath, projectPath, interactive);
SendPacket(packet);
// Wait for either the response or a shutdown event. Either event means this thread should return
WaitHandle.WaitAny(new WaitHandle[] { _responseReceivedEvent, ShutdownEvent });
// Keep track of the element location of the reference
_lastResponse.ElementLocation = sdkReferenceLocation;
// Return the response which was set by another thread. In the case of shutdown, it should be null.
return(_lastResponse);
}
