/// <summary>
/// Supervises your application and if it exits or crashes it will be automatically restarted.
/// NB! This method _MUST_ be invoked after <see cref="ProcessEvents"/>. You can stop the supervisor
/// process by invoking <see cref="StopSupervisor"/> before exiting the application.
/// </summary>
/// <param name="restartArguments"></param>
public static bool StartSupervisor(List <string> restartArguments = null)
{
StopSupervisor();
if (!SnapOs.Filesystem.FileExists(SuperVisorProcessExeDirectory))
{
Logger.Error($"Unable to find supervisor executable: {SuperVisorProcessExeDirectory}");
return(false);
}
var superVisorId = Current.SuperVisorId;
var coreRunArgument = $"--corerun-supervise-pid={SnapOs.ProcessManager.Current.Id} --corerun-supervise-id={superVisorId}";
SuperVisorProcess = SnapOs.ProcessManager.StartNonBlocking(new ProcessStartInfoBuilder(SuperVisorProcessExeDirectory)
.AddRange(restartArguments ?? new List <string>())
.Add(coreRunArgument)
);
SupervisorProcessRestartArguments = restartArguments ?? new List <string>();
Logger.Debug($"Enabled supervision of process with id: {SnapOs.ProcessManager.Current.Id}. Supervisor id: {superVisorId}. " +
$"Restart arguments({SupervisorProcessRestartArguments.Count}): {string.Join(",", SupervisorProcessRestartArguments)}. ");
SuperVisorProcess.Refresh();
return(!SuperVisorProcess.HasExited);
}
public static bool StopSupervisor()
{
try
{
if (SuperVisorProcess == null)
{
return(false);
}
SuperVisorProcess.Refresh();
var supervisorRunning = !SuperVisorProcess.HasExited;
if (!supervisorRunning)
{
return(false);
}
if (!RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
{
// ReSharper disable once InconsistentNaming
const int SIGTERM = 15;
// We have to signal the supervisor so we can release the machine wide semaphore.
var killResult = CoreRunLib.NativeMethodsUnix.kill(SuperVisorProcess.Id, SIGTERM);
var killSuccess = killResult == 0;
if (!killSuccess)
{
Logger.Warn($"Failed to signal ({nameof(SIGTERM)}) supervisor. Return code: {killResult}.");
return(false);
}
Logger.Info($"Successfully signaled ({nameof(SIGTERM)}) supervisor.");
var attempts = 3;
while (attempts-- >= 0)
{
SuperVisorProcess.Refresh();
supervisorRunning = !SuperVisorProcess.HasExited;
if (!supervisorRunning)
{
break;
}
Thread.Sleep(100);
}
return(!supervisorRunning);
}
SuperVisorProcess.Kill();
SuperVisorProcess.Refresh();
supervisorRunning = !SuperVisorProcess.HasExited;
return(!supervisorRunning);
}
catch (Exception e)
{
Logger.ErrorException($"Exception thrown when killing supervisor process with pid: {SuperVisorProcess?.Id}", e);
}
SuperVisorProcess = null;
return(false);
}
