void Simulator::handleIO( const Operation& operation, int pid )
{
string startMsg = "I/O: process " + to_string(pid) + " starting ";
string endMsg = "Interrupt: process " + to_string(pid) + " done with ";
if( operation.parameters().description == "hard drive" )
{
string type = operation.parameters().id == 'I' ? "input" : "output";
display( startMsg + "hard drive " + type );
wait( operation.parameters().duration );
display( startMsg + "hard drive " + type );
}
else if( operation.parameters().description == "keyboard" )
{
display( startMsg + "keyboard input" );
wait( operation.parameters().duration );
display( endMsg + "keyboard input" );
}
else if( operation.parameters().description == "printer" )
{
display( startMsg + "printer output" );
wait( operation.parameters().duration );
display( endMsg + "printer output" );
}
else if( operation.parameters().description == "monitor" )
{
display( startMsg + "monitor output" );
wait( operation.parameters().duration );
display( endMsg + "monitor output" );
}
interrupts_.push(pid);
}
void Simulator::executeProgram( Program *program )
{
int pid = program->process_control_block().processID;
Operation* operation = program->step();
char operationType = operation->parameters().id;
// Create thread lambda
auto ThreadStart = [this, operation, pid]()
{
handleIO(*operation, pid);
};
program->run();
// Start
if( operationType == 'A' &&
operation->parameters().description == "start")
{
display("OS: starting process " + to_string(pid));
operation = program->step();
}
// I/O
if( operationType == 'I' || operationType == 'O')
{
display("Process: " + to_string(pid) + ": starting I/O");
thread IO_thread(ThreadStart);
IO_thread.detach(); // async, do not block
program->suspend();
suspendedPrograms_[pid] = *program;
}
// Processing
else if( operationType == 'P' )
{
display("Process " + to_string(pid) + ": processing action");
int quantum = 0;
while( !operation->completed() && interrupts_.empty() )
{
quantum++;
operation = program->step();
wait( operation->parameters().cycleTime );
if( quantum == configurationData.quantum )
{
// Launch a quantum interrupt to stop execution of the program
interrupts_.push(0);
display("Interrupt: quantum expired");
}
}
if( operation->completed() )
{
display("Process " + to_string(pid) + ": end processing action");
}
}
// The last operation in a program is an exit operation
if( program->operations_left() <= 1 &&
program->process_control_block().state != SUSPENDED)
{
program->exit();
display("OS: removing process " + to_string(pid));
}
}