/// <summary>
/// The main external agent server.
/// </summary>
/// <param name="args">command line arguments.</param>
public static void Main(string[] args)
{
string executableFilePath = null;
Uri optimizerAddressUri = null;
CliOptionsParser.ParseArgs(args, out executableFilePath, out optimizerAddressUri);
// Check for the executable before setting up any shared memory to
// reduce cleanup issues.
//
if (executableFilePath != null && !File.Exists(executableFilePath))
{
throw new FileNotFoundException($"ERROR: --executable '{executableFilePath}' does not exist.");
}
Console.WriteLine("Mlos.Agent.Server");
TargetProcessManager targetProcessManager = null;
// Connect to gRpc optimizer only if user provided an address in the command line.
//
if (optimizerAddressUri != null)
{
Console.WriteLine("Connecting to the Mlos.Optimizer");
// This switch must be set before creating the GrpcChannel/HttpClient.
//
AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
// This populates a variable for the various settings registry
// callback handlers to use (by means of their individual
// AssemblyInitializers) to know how they can connect with the
// optimizer.
//
// See Also: AssemblyInitializer.cs within the SettingsRegistry
// assembly project in question.
//
MlosContext.OptimizerFactory = new MlosOptimizer.BayesianOptimizerFactory(optimizerAddressUri);
}
// In the active learning mode, create a new shared memory map before running the target process.
// On Linux, we unlink existing shared memory map, if they exist.
// If the agent is not in the active learning mode, create new or open existing to communicate with the target process.
//
using MlosContext mlosContext = (executableFilePath != null)
? InterProcessMlosContext.Create()
: InterProcessMlosContext.CreateOrOpen();
using var mainAgent = new MainAgent();
mainAgent.InitializeSharedChannel(mlosContext);
// Active learning mode.
//
// TODO: In active learning mode the MlosAgentServer can control the
// workload against the target component.
//
if (executableFilePath != null)
{
Console.WriteLine($"Starting {executableFilePath}");
targetProcessManager = new TargetProcessManager(executableFilePath: executableFilePath);
targetProcessManager.StartTargetProcess();
}
else
{
Console.WriteLine("No executable given to launch. Will wait for agent to connect independently.");
}
var cancellationTokenSource = new CancellationTokenSource();
Task grpcServerTask = CreateHostBuilder(Array.Empty <string>()).Build().RunAsync(cancellationTokenSource.Token);
// Start the MainAgent message processing loop as a background thread.
//
// In MainAgent.RunAgent we loop on the shared memory control and
// telemetry channels looking for messages and dispatching them to
// their registered callback handlers.
//
// The set of recognized messages is dynamically registered using
// the RegisterSettingsAssembly method which is called through the
// handler for the RegisterAssemblyRequestMessage.
//
// Once registered, the SettingsAssemblyManager uses reflection to
// search for an AssemblyInitializer inside those assemblies and
// executes it in order to setup the message handler callbacks
// within the agent.
//
// See Also: AssemblyInitializer.cs within the SettingsRegistry
// assembly project in question.
//
Console.WriteLine("Starting Mlos.Agent");
Task mlosAgentTask = Task.Factory.StartNew(
() => mainAgent.RunAgent(),
CancellationToken.None,
TaskCreationOptions.LongRunning,
TaskScheduler.Current);
Task waitForTargetProcessTask = Task.Factory.StartNew(
() =>
{
if (targetProcessManager != null)
{
targetProcessManager.WaitForTargetProcessToExit();
targetProcessManager.Dispose();
mainAgent.UninitializeSharedChannel();
}
},
CancellationToken.None,
TaskCreationOptions.LongRunning,
TaskScheduler.Current);
Console.WriteLine("Waiting for Mlos.Agent to exit");
while (true)
{
Task.WaitAny(mlosAgentTask, waitForTargetProcessTask);
if (mlosAgentTask.IsFaulted && targetProcessManager != null && !waitForTargetProcessTask.IsCompleted)
{
// MlosAgentTask has failed, however the target process is still active.
// Terminate the target process and continue shutdown.
//
targetProcessManager.TerminateTargetProcess();
continue;
}
if (mlosAgentTask.IsCompleted && waitForTargetProcessTask.IsCompleted)
{
// MlosAgentTask is no longer processing messages, and target process does no longer exist.
// Shutdown the agent.
//
break;
}
}
// Print any exceptions if occurred.
//
if (mlosAgentTask.Exception != null)
{
Console.WriteLine($"Exception: {mlosAgentTask.Exception}");
}
if (waitForTargetProcessTask.Exception != null)
{
Console.WriteLine($"Exception: {waitForTargetProcessTask.Exception}");
}
// Perform some cleanup.
//
waitForTargetProcessTask.Dispose();
mlosAgentTask.Dispose();
targetProcessManager?.Dispose();
cancellationTokenSource.Cancel();
grpcServerTask.Wait();
grpcServerTask.Dispose();
cancellationTokenSource.Dispose();
Console.WriteLine("Mlos.Agent exited.");
}
/// <summary>
/// The main external agent server.
/// </summary>
/// <param name="args">command line arguments.</param>
/// <returns>Returns exit code.</returns>
public static int Main(string[] args)
{
CliOptionsParser.CliOptions parserOptions = CliOptionsParser.ParseArgs(args);
if (!string.IsNullOrEmpty(parserOptions.ExperimentFilePath) && !File.Exists(parserOptions.ExperimentFilePath))
{
throw new FileNotFoundException($"ERROR: --experiment '{parserOptions.ExperimentFilePath}' does not exist.");
}
if (!string.IsNullOrEmpty(parserOptions.SettingsRegistryPath))
{
// #TODO temporary hack
//
Environment.SetEnvironmentVariable("MLOS_SETTINGS_REGISTRY_PATH", parserOptions.SettingsRegistryPath);
}
Console.WriteLine("Mlos.Agent.Server");
// Active learning mode.
//
// TODO: In active learning mode the MlosAgentServer can control the
// workload against the target component.
//
TargetProcessManager targetProcessManager = null;
if (parserOptions.Executable != null)
{
Console.WriteLine($"Starting: '{parserOptions.Executable}'");
targetProcessManager = new TargetProcessManager(executableFilePath: parserOptions.Executable);
targetProcessManager.StartTargetProcess();
Console.WriteLine($"Launched process: '{Path.GetFileName(parserOptions.Executable)}'");
}
else
{
Console.WriteLine("No executable given to launch. Will wait for agent to connect independently.");
}
// Create a Mlos context.
//
using MlosContext mlosContext = MlosContextFactory.Create();
// Connect to gRpc optimizer only if user provided an address in the command line.
//
if (parserOptions.OptimizerUri != null)
{
Console.WriteLine("Connecting to the Mlos.Optimizer");
// This switch must be set before creating the GrpcChannel/HttpClient.
//
AppContext.SetSwitch("System.Net.Http.SocketsHttpHandler.Http2UnencryptedSupport", true);
// This populates a variable for the various settings registry
// callback handlers to use (by means of their individual
// ExperimentSession instances) to know how they can connect with
// the optimizer.
//
// See SmartCacheExperimentSession.cs for an example.
//
mlosContext.OptimizerFactory = new MlosOptimizer.BayesianOptimizerFactory(parserOptions.OptimizerUri);
}
var experimentSessionManager = new ExperimentSessionManager(mlosContext);
using var mainAgent = new MainAgent();
mainAgent.InitializeSharedChannel(mlosContext);
// If specified, load the experiment assembly.
//
if (!string.IsNullOrEmpty(parserOptions.ExperimentFilePath))
{
experimentSessionManager.LoadExperiment(parserOptions.ExperimentFilePath);
}
var cancellationTokenSource = new CancellationTokenSource();
Task grpcServerTask = CreateHostBuilder(Array.Empty <string>()).Build().RunAsync(cancellationTokenSource.Token);
// Start the MainAgent message processing loop as a background thread.
//
// In MainAgent.RunAgent we loop on the shared memory control and
// telemetry channels looking for messages and dispatching them to
// their registered callback handlers.
//
// The set of recognized messages is dynamically registered using
// the RegisterSettingsAssembly method which is called through the
// handler for the RegisterAssemblyRequestMessage.
//
// Once registered, the ExperimentSessionManager can creates an
// instance of the requested ExperimentSession in order to setup the
// message handler callbacks for the components messages within the
// agent.
//
// See SmartCacheExperimentSession.cs for an example.
//
Console.WriteLine("Starting Mlos.Agent");
Task mlosAgentTask = Task.Factory.StartNew(
() => mainAgent.RunAgent(),
CancellationToken.None,
TaskCreationOptions.LongRunning,
TaskScheduler.Current);
Task waitForTargetProcessTask = Task.Factory.StartNew(
() =>
{
if (targetProcessManager != null)
{
targetProcessManager.WaitForTargetProcessToExit();
targetProcessManager.Dispose();
mainAgent.UninitializeSharedChannel();
}
},
CancellationToken.None,
TaskCreationOptions.LongRunning,
TaskScheduler.Current);
Console.WriteLine("Waiting for Mlos.Agent to exit");
while (true)
{
Task.WaitAny(mlosAgentTask, waitForTargetProcessTask);
if (mlosAgentTask.IsFaulted && targetProcessManager != null && !waitForTargetProcessTask.IsCompleted)
{
// MlosAgentTask has failed, however the target process is still active.
// Terminate the target process and continue shutdown.
//
targetProcessManager.TerminateTargetProcess();
continue;
}
if (mlosAgentTask.IsCompleted && waitForTargetProcessTask.IsCompleted)
{
// MlosAgentTask is no longer processing messages, and target process does no longer exist.
// Shutdown the agent.
//
break;
}
}
int exitCode = 0;
// Print any exceptions if occurred.
//
if (mlosAgentTask.Exception != null)
{
Console.WriteLine($"Exception: {mlosAgentTask.Exception}");
exitCode |= 1;
}
if (waitForTargetProcessTask.Exception != null)
{
Console.WriteLine($"Exception: {waitForTargetProcessTask.Exception}");
exitCode |= 2;
}
// Perform some cleanup.
//
waitForTargetProcessTask.Dispose();
mlosAgentTask.Dispose();
targetProcessManager?.Dispose();
cancellationTokenSource.Cancel();
grpcServerTask.Wait();
grpcServerTask.Dispose();
cancellationTokenSource.Dispose();
Console.WriteLine("Mlos.Agent exited.");
return(exitCode);
}