/// <summary>
/// Creates a task that runs Gurobi on the given instance.
/// </summary>
/// <param name="instance">
/// Instance to run on.
/// </param>
/// <param name="cancellationToken">
/// The cancellation token given to the task. NOTE: In this implementation, we ignore this cancellation token, since Gurobi uses its own cancellation token in the callback.
/// </param>
/// <returns>
/// A task that returns the run's runtime, gap, feasibility and completion status onto return.
/// </returns>
public Task <GurobiResult> Run(InstanceSeedFile instance, CancellationToken cancellationToken)
{
// Check if the runner has already been disposed.
if (this._hasAlreadyBeenDisposed)
{
throw new ObjectDisposedException("GurobiRunner", "Called Run on a disposed GurobiRunner.");
}
// Continue if it hasn't.
// ReSharper disable once MethodSupportsCancellation
var solveTask = Task.Run(
() =>
{
this._recordTimer = null;
try
{
// Prepare Gurobi model: Use configured _environment and the given instance,
// then add a cancellation token source and the Gurobi callback for cancellation.
var instanceFile = new FileInfo(instance.Path);
if (!File.Exists(instanceFile.FullName))
{
throw new FileNotFoundException($"Instance {instanceFile.FullName} not found!");
}
LoggingHelper.WriteLine(VerbosityLevel.Debug, $"Setting MIPGap to {this._runnerConfiguration.TerminationMipGap}");
this._environment.MIPGap = this._runnerConfiguration.TerminationMipGap;
LoggingHelper.WriteLine(VerbosityLevel.Debug, $"Current Seed: {instance.Seed}");
this._environment.Seed = instance.Seed;
this._environment.TimeLimit = this._runnerConfiguration.CpuTimeout.TotalSeconds;
if (!Directory.Exists("GurobiLog"))
{
Directory.CreateDirectory("GurobiLog");
}
var instanceFileNameWithoutExtension = GurobiUtils.GetFileNameWithoutGurobiExtension(instanceFile);
this._environment.LogFile = "GurobiLog" + Path.DirectorySeparatorChar
+ $"GurobiRunner_{DateTime.Now:yy-MM-dd_HH-mm-ss-ffff}_"
+ instanceFileNameWithoutExtension + $"_{Guid.NewGuid()}.log";
var model = new GRBModel(this._environment, instanceFile.FullName)
{
ModelName = instanceFileNameWithoutExtension
};
if (GurobiRunner.TryToGetMstFile(instanceFile.DirectoryName, instanceFileNameWithoutExtension, out var mstFileFullName))
{
model.Read(mstFileFullName);
}
this._startTimeStamp = DateTime.Now;
this._targetAlgorithmStatus = TargetAlgorithmStatus.Running;
this._innerCancellationTokenSource = new CancellationTokenSource(this._runnerConfiguration.CpuTimeout);
this._grbCallback = new GurobiCallback(
this._innerCancellationTokenSource.Token,
this._tunerConfiguration.EnableDataRecording,
this._startTimeStamp);
model.SetCallback(this._grbCallback);
if (this._tunerConfiguration.EnableDataRecording)
{
this._lastRuntimeFeatures = null;
this.SetGurobiInstanceFeatures(model);
// Start record timer.
var autoResetEvent = new AutoResetEvent(false);
this._recordTimer = new Timer(
(timerCallback) =>
{
var currentTimeStamp = DateTime.Now;
if (currentTimeStamp - this._startTimeStamp < this._runnerConfiguration.CpuTimeout)
{
// Write current line to data log.
var currentAdapterData = this.CreateCurrentAdapterDataRecord(currentTimeStamp);
this.OnNewDataRecord?.Invoke(this, currentAdapterData);
}
},
autoResetEvent,
TimeSpan.FromSeconds(0),
this._tunerConfiguration.DataRecordUpdateInterval);
}
// Optimize. This step may be aborted in the callback.
model.Optimize();
if (this._targetAlgorithmStatus != TargetAlgorithmStatus.CancelledByGrayBox)
{
this._recordTimer?.Dispose();
this._targetAlgorithmStatus = this.GetIsRunInterrupted(model)
? TargetAlgorithmStatus.CancelledByTimeout
: TargetAlgorithmStatus.Finished;
}
var finalTimeStamp = DateTime.Now;
var result = this.CreateGurobiResult(finalTimeStamp, model);
if (this._tunerConfiguration.EnableDataRecording)
{
// Write last line to data log.
var lastAdapterData = this.CreateFinalAdapterDataRecord(finalTimeStamp, model, result);
this.OnNewDataRecord?.Invoke(this, lastAdapterData);
}
// Before returning, dispose of Gurobi model.
model.Dispose();
return(result);
}
finally
{
this._recordTimer?.Dispose();
}
});
return(solveTask);
}
