/// <summary>
/// Runs the execution engine, which eternally processes execution
/// requests posted to the main queue.
/// </summary>
public void Run()
{
this.keepSwimming = true;
while (this.keepSwimming)
{
// Pull request off queue.
Console.WriteLine("Waiting for new work request.");
CloudExecutionRequest executionRequest = this.mainQueue.GetRequest(block: true);
if (!this.keepSwimming)
{
// Exit without deleting request from queue.
// Request will become visible again after timeout expires.
break;
}
// TODO: For now, we immediately delete the requests we take.
// Eventually we'll want to leave the request invisible until
// some timeout expires so that other engines can pick it up
// if we crash.
this.mainQueue.DeleteRequest(executionRequest);
Console.WriteLine("Received request with ID {0}.", executionRequest.Identifier);
// Make a progress report to soothe nervous users.
CloudExecutionReport statusUpdate = new CloudExecutionReport(
executionRequest.Identifier,
CloudExecutionReport.StatusCode.InProgress,
0,
null,
null,
0,
null);
// Submit progress report.
this.mainQueue.SubmitReport(statusUpdate, executionRequest.ReportQueue);
// Do the requested operation.
CloudExecutionReport report = null;
switch (executionRequest.RequestedOperation)
{
case CloudExecutionRequest.Operation.RunExecutable:
report = this.RunAnExecutable(executionRequest);
break;
case CloudExecutionRequest.Operation.CommitSuicide:
this.keepSwimming = false;
goto case CloudExecutionRequest.Operation.None;
case CloudExecutionRequest.Operation.DeleteQueue:
this.mainQueue.DeleteQueue(executionRequest.ReportQueue);
goto case CloudExecutionRequest.Operation.None;
case CloudExecutionRequest.Operation.None:
report = new CloudExecutionReport(
executionRequest.Identifier,
CloudExecutionReport.StatusCode.Completed);
break;
default:
// ToDo: This should probably be treated as an error.
goto case CloudExecutionRequest.Operation.None;
}
// Submit report.
this.mainQueue.SubmitReport(report, executionRequest.ReportQueue);
}
}
/// <summary>
/// Run the requested executable and produce a report of the results.
/// </summary>
/// <param name="executionRequest">The execution request.</param>
/// <returns>A report of the results.</returns>
private CloudExecutionReport RunAnExecutable(CloudExecutionRequest executionRequest)
{
// REVIEW: How/whether to use this.
BuildObject diagnosticsBase = new BuildObject(Path.Combine("nuobj", "diagnostics", "process"));
// Prep working directory with input files and output dirs.
// TODO: The below will throw cache exceptions if something
// isn't there (they should all be though). Need to catch
// these and fail the execution request when this happens.
WorkingDirectory workingDirectory = new WorkingDirectory(this.virtualIronRoot);
foreach (BuildObjectValuePointer inputFile in executionRequest.InputFileMappings)
{
// REVIEW: How to determine cache container here.
ItemCacheContainer container = ItemCacheContainer.Sources;
if (this.multiplexedItemCache.GetItemSize(container, inputFile.ObjectHash) == -1)
{
container = ItemCacheContainer.Objects;
}
// TODO: Move path/directory manipulation code into
// WorkingDirectory and/or ItemCache.
string inputFilePath = workingDirectory.PathTo(inputFile.RelativePath);
Directory.CreateDirectory(Path.GetDirectoryName(inputFilePath)); // REVIEW: Still neeeded?
this.multiplexedItemCache.FetchItemToFile(
container,
inputFile.ObjectHash,
inputFilePath);
}
foreach (BuildObject outputFile in executionRequest.OutputFiles)
{
workingDirectory.CreateDirectoryFor(outputFile);
}
// Run executable.
ProcessInvoker pinv = new ProcessInvoker(
workingDirectory,
executionRequest.Executable,
new string[] { executionRequest.Arguments },
diagnosticsBase,
null, // This is captureStdout. TODO: Should cleanup how this is used in ProcessInvoker.
null); // This is dbgText. REVIEW: How/whether to use this.
// When ProcessInvoker's constructor returns, the process has
// finished running.
Console.WriteLine("Request {0} completed in {1} seconds.", executionRequest.Identifier, pinv.CpuTime);
// Store output files in the (cloud) item cache, and create a
// list of the mappings.
List <BuildObjectValuePointer> outputFileMappings = new List <BuildObjectValuePointer>();
foreach (BuildObject outFile in executionRequest.OutputFiles)
{
if (File.Exists(workingDirectory.PathTo(outFile)))
{
string fileHash = Util.hashFilesystemPath(workingDirectory.PathTo(outFile));
Util.Assert(!string.IsNullOrEmpty(fileHash));
// Note we explicitly write to the cloud cache here.
this.cloudCache.StoreItemFromFile(ItemCacheContainer.Objects, fileHash, workingDirectory.PathTo(outFile));
outputFileMappings.Add(new BuildObjectValuePointer(fileHash, outFile.getRelativePath()));
}
}
// Collect the results into a report.
CloudExecutionReport report = new CloudExecutionReport(
executionRequest.Identifier,
CloudExecutionReport.StatusCode.Completed,
pinv.ExitCode,
pinv.GetStdout(),
pinv.GetStderr(),
pinv.CpuTime,
outputFileMappings);
return(report);
}
