public BackgroundProcessingServer(DataStorage storage, BackgroundProcessingServerOptions options, IDictionary <string, object> properties, IEnumerable <IBackgroundProcess> processes)
{
if (storage == null)
{
throw new ArgumentNullException(nameof(storage));
}
if (processes == null)
{
throw new ArgumentNullException(nameof(processes));
}
if (properties == null)
{
throw new ArgumentNullException(nameof(properties));
}
_options = options ?? throw new ArgumentNullException(nameof(options));
_processes.AddRange(processes);
_processes.AddRange(GetRequiredProcesses());
var context = new BackgroundProcessContext(
serverId: _options.ServerName,
cancellationToken: _cts.Token,
storage: storage,
properties: properties,
serverContext: options.ServerContext
);
_bootstrapTask = WrapProcess(this).CreateTask(context);
}
private static void RunProcess(IBackgroundProcess process, BackgroundProcessContext context)
{
// Long-running tasks are based on custom threads (not threadpool ones) as in
// .NET Framework 4.5, so we can try to set custom thread name to simplify the
// debugging experience.
TrySetThreadName(process.ToString());
// LogProvider.GetLogger does not throw any exception, that is why we are not
// using the `try` statement here. It does not return `null` value as well.
var logger = LogProvider.GetLogger();
logger.Log(LogLevel.Debug, $"Background process '{process}' started.");
try
{
process.Execute(context);
}
catch (Exception ex)
{
if (ex is OperationCanceledException && context.IsShutdownRequested)
{
// Graceful shutdown
logger.Log(LogLevel.Debug, $"Background process '{process}' was stopped due to a shutdown request.");
}
else
{
logger.Log(LogLevel.Fatal, $"Fatal error occurred during execution of '{process}' process. It will be stopped. See the exception for details.", ex);
}
}
logger.Log(LogLevel.Debug, $"Background process '{process}' stopped.");
}
public void Execute(BackgroundProcessContext context)
{
try
{
var tasks = _processes
.Select(WrapProcess)
.Select(process => process.CreateTask(context))
.ToArray();
Task.WaitAll(tasks);
}
finally
{
context.Storage.RemoveServer(context.ServerId);
}
}
public static Task CreateTask(this IBackgroundProcess process, BackgroundProcessContext context)
{
if (process == null)
{
throw new ArgumentNullException(nameof(process));
}
if (!(process is IBackgroundProcess))
{
throw new ArgumentOutOfRangeException(nameof(process), "Long-running process must be of type IServerComponent or IBackgroundProcess.");
}
return(Task.Factory.StartNew(
() => RunProcess(process, context),
TaskCreationOptions.LongRunning));
}
public static void Execute(this IBackgroundProcess process, BackgroundProcessContext context)
{
process.Execute(context);
}
