/** @internal actually bring down any calculation processes
* and finally disconnect any external input/output interfaces.
* This shutdown and cleanup operation is executed in a separate
* "Output shutdown supervisor" thread and has the liability to
* bring down the relevant facilities within a certain timespan.
* When done, the last operation within this thread will be to
* invoke the callback signal given as parameter.
* @note locks the OutputDirector
*/
void
OutputDirector::bringDown (SigTerm completedSignal)
{
Lock sync(this);
string problemLog;
if (not isOperational())
{
WARN (play, "Attempt to OutputDirector::bringDown() -- "
"which it is not in running state. Invocation ignored. "
"This indicates an error in Lifecycle logic.");
return;
}
try
{
TODO ("actually bring down the output generation");
player_.shutdown();
completedSignal(0);
}
catch (lumiera::Error& problem)
{
problemLog = problem.what();
lumiera_error(); // reset error state
completedSignal (&problemLog);
}
catch (...)
{
problemLog = "Unknown error while disconnecting output. "
"Lumiera error flag is = "+string(lumiera_error());
completedSignal (&problemLog);
}
}
/** @param name to use in log and error messages
* @note does error handling, but delegates the actual
* execution to the protected (subclass) member */
ExecResult
HandlingPattern::invoke (CommandImpl& command, Symbol name) const
{
TRACE (proc_dbg, "invoking %s...", name.c());
static format err_pre ("Error state detected, %s *NOT* invoked.");
static format err_post ("Error state after %s invocation.");
static format err_fatal ("Execution of %s raised unknown error.");
try
{
Symbol errID_pre = lumiera_error();
if (errID_pre)
return ExecResult (error::Logic (str (err_pre % command), errID_pre));
// execute or undo it...
perform (command);
Symbol errID = lumiera_error();
if (errID)
return ExecResult (error::State (str (err_post % command),errID));
else
return ExecResult();
}
catch (lumiera::Error& problem)
{
Symbol errID = lumiera_error();
WARN (command, "Invocation of %s failed: %s", name.c(), problem.what());
TRACE (proc_dbg, "Error flag was: %s", errID.c());
return ExecResult (problem);
}
catch (std::exception& library_problem)
{
Symbol errID = lumiera_error();
WARN (command, "Invocation of %s failed: %s", name.c(), library_problem.what());
TRACE (proc_dbg, "Error flag was: %s", errID.c());
return ExecResult (error::External (library_problem));
}
catch (...)
{
Symbol errID = lumiera_error();
ERROR (command, "Invocation of %s failed with unknown exception; error flag is: %s", name.c(), errID.c());
throw error::Fatal (str (err_fatal % command), errID);
}
}
/** @note as an optimisation we hand out a direct reference
* to the implementing process object. While this ref could
* still be passed as handle to the C Language interface, using
* it directly within the client (=GUI) bypasses the C interface
* and thus leaves us only with one level of indirection,
* irrespective if using the C or C++ interface.
* @note in hindsight this turned out as a very bad idea,
* since it complicated the definition of the facade proxy
* and created quite involved library dependency problems.
*/
Process start(LumieraDisplaySlot viewerHandle)
{
ProcessImplementationLink* pP = static_cast<ProcessImplementationLink*> (_i_.startPlay (viewerHandle));
if (!pP)
throw lumiera::error::State("failed to start DummyPlayer", lumiera_error());
return pP->createHandle();
}