// for emergencies only!
//-------------------------------------------------
// eat_all_cycles - eat a ton of cycles on all
// CPUs to force a quick exit
//-------------------------------------------------
public void eat_all_cycles()
{
for (device_execute_interface exec = m_execute_list; exec != null; exec = exec.nextexec)
{
exec.eat_cycles(1000000000);
}
}
// scheduling helpers
//-------------------------------------------------
// compute_perfect_interleave - compute the
// "perfect" interleave interval
//-------------------------------------------------
public void compute_perfect_interleave()
{
// ensure we have a list of executing devices
if (m_execute_list == null)
{
rebuild_execute_list();
}
// start with the first one
device_execute_interface first = m_execute_list;
if (first != null)
{
// start with a huge time factor and find the 2nd smallest cycle time
attoseconds_t smallest = first.minimum_quantum();
attoseconds_t perfect = attotime.ATTOSECONDS_PER_SECOND - 1;
for (device_execute_interface exec = first.nextexec; exec != null; exec = exec.nextexec)
{
// find the 2nd smallest cycle interval
attoseconds_t curquantum = exec.minimum_quantum();
if (curquantum < smallest)
{
perfect = smallest;
smallest = curquantum;
}
else if (curquantum < perfect)
{
perfect = curquantum;
}
}
// if this is a new minimum quantum, apply it
if (m_quantum_minimum != perfect)
{
// adjust all the actuals; this doesn't affect the current
m_quantum_minimum = perfect;
for (quantum_slot quant = m_quantum_list.first(); quant != null; quant = quant.next())
{
quant.actual_set(Math.Max(quant.requested(), m_quantum_minimum));
}
}
}
}
//-------------------------------------------------
// apply_suspend_changes - applies suspend/resume
// changes to all device_execute_interfaces
//-------------------------------------------------
void apply_suspend_changes()
{
u32 suspendchanged = 0;
for (device_execute_interface exec = m_execute_list; exec != null; exec = exec.nextexec)
{
suspendchanged |= exec.suspend_ ^ exec.nextsuspend;
exec.suspend_ = exec.nextsuspend;
exec.nextsuspend &= ~device_execute_interface.SUSPEND_REASON_TIMESLICE;
exec.eatcycles = exec.nexteatcycles;
}
// recompute the execute list if any CPUs changed their suspension state
if (suspendchanged != 0)
{
rebuild_execute_list();
}
else
{
m_suspend_changes_pending = false;
}
}
//-------------------------------------------------
// rebuild_execute_list - rebuild the list of
// executing CPUs, moving suspended CPUs to the
// end
//-------------------------------------------------
void rebuild_execute_list()
{
// if we haven't yet set a scheduling quantum, do it now
if (m_quantum_list.empty())
{
// set the core scheduling quantum
attotime min_quantum = machine().config().minimum_quantum;
// if none specified default to 60Hz
if (min_quantum.is_zero())
{
min_quantum = attotime.from_hz(60);
}
// if the configuration specifies a device to make perfect, pick that as the minimum
if (!machine().config().perfect_cpu_quantum().empty())
{
device_t device = machine().root_device().subdevice(machine().config().perfect_cpu_quantum().c_str());
if (device == null)
{
fatalerror("Device '{0}' specified for perfect interleave is not present!\n", machine().config().perfect_cpu_quantum());
}
device_execute_interface exec;
if (!device.interface_(out exec))
{
fatalerror("Device '{0}' specified for perfect interleave is not an executing device!\n", machine().config().perfect_cpu_quantum());
}
min_quantum = attotime.Min(new attotime(0, exec.minimum_quantum()), min_quantum);
}
// make sure it's no higher than 60Hz
min_quantum = attotime.Min(min_quantum, attotime.from_hz(60));
// inform the timer system of our decision
add_scheduling_quantum(min_quantum, attotime.never);
}
// start with an empty list
//device_execute_interface **active_tailptr = &m_execute_list;
//*active_tailptr = NULL;
// also make an empty list of suspended devices
//device_execute_interface *suspend_list = NULL;
//device_execute_interface **suspend_tailptr = &suspend_list;
List <device_execute_interface> active_list = new List <device_execute_interface>();
List <device_execute_interface> suspend_list = new List <device_execute_interface>();
// iterate over all devices
foreach (device_execute_interface exec in new execute_interface_iterator(machine().root_device()))
{
// append to the appropriate list
exec.nextexec = null;
if (exec.suspend_ == 0)
{
//*active_tailptr = exec;
//active_tailptr = &exec.m_nextexec;
active_list.Add(exec);
}
else
{
//*suspend_tailptr = exec;
//suspend_tailptr = &exec.m_nextexec;
suspend_list.Add(exec);
}
}
// append the suspend list to the end of the active list
//*active_tailptr = suspend_list;
active_list.AddRange(suspend_list);
if (active_list.Count > 0)
{
m_execute_list = active_list[0];
for (int i = 0; i < active_list.Count; i++)
{
if (i < active_list.Count - 1)
{
active_list[i].nextexec = active_list[i + 1];
}
else
{
active_list[i].nextexec = null;
}
}
}
}
// execution
//-------------------------------------------------
// timeslice - execute all devices for a single
// timeslice
//-------------------------------------------------
public void timeslice()
{
bool call_debugger = (machine().debug_flags_get & machine_global.DEBUG_FLAG_ENABLED) != 0;
// build the execution list if we don't have one yet
//if (UNEXPECTED(m_execute_list == null))
if (m_execute_list == null)
{
rebuild_execute_list();
}
// if the current quantum has expired, find a new one
while (m_basetime >= m_quantum_list.first().expire())
{
m_quantum_allocator.reclaim(m_quantum_list.detach_head());
}
// loop until we hit the next timer
while (m_basetime < m_timer_list.expire())
{
// by default, assume our target is the end of the next quantum
attotime target = m_basetime + new attotime(0, m_quantum_list.first().actual());
// however, if the next timer is going to fire before then, override
if (m_timer_list.expire() < target)
{
target = m_timer_list.expire();
}
if (machine().video().frame_update_count() % 1000 == 0)
{
//LOG(("------------------\n"));
LOG("device_scheduler.timeslice() - cpu_timeslice: target = {0}, m_timer_list.expire: {1}\n", target.as_string(), m_timer_list.expire().as_string());
}
// do we have pending suspension changes?
if (m_suspend_changes_pending)
{
apply_suspend_changes();
}
// loop over all CPUs
for (device_execute_interface exec = m_execute_list; exec != null; exec = exec.nextexec)
{
// only process if this CPU is executing or truly halted (not yielding)
// and if our target is later than the CPU's current time (coarse check)
//if (EXPECTED((exec.m_suspend == 0 || exec.m_eatcycles) && target.seconds >= exec.m_localtime.seconds))
if ((exec.suspend_ == 0 || exec.eatcycles > 0) && target.seconds() >= exec.localtime.seconds())
{
// compute how many attoseconds to execute this CPU
attoseconds_t delta = target.attoseconds() - exec.localtime.attoseconds();
if (delta < 0 && target.seconds() > exec.localtime.seconds())
{
delta += attotime.ATTOSECONDS_PER_SECOND;
}
assert(delta == (target - exec.localtime).as_attoseconds());
if (exec.attoseconds_per_cycle == 0)
{
exec.localtime = target;
}
// if we have enough for at least 1 cycle, do the math
else if (delta >= exec.attoseconds_per_cycle)
{
// compute how many cycles we want to execute
int ran = exec.cycles_running = (int)divu_64x32((UInt64)delta >> exec.divshift, (UInt32)exec.divisor);
if (machine().video().frame_update_count() % 1000 == 0)
{
LOG("device_scheduler.timeslice() - cpu '{0}': {1} ({2} cycles)\n", exec.device().tag(), delta, exec.cycles_running);
}
// if we're not suspended, actually execute
if (exec.suspend_ == 0)
{
profiler_global.g_profiler.start(exec.profiler);
// note that this global variable cycles_stolen can be modified
// via the call to cpu_execute
exec.cycles_stolen = 0;
m_executing_device = exec;
exec.icount_set(exec.cycles_running); // *exec->m_icountptr = exec->m_cycles_running;
if (!call_debugger)
{
exec.run();
}
else
{
exec.debugger_start_cpu_hook(target);
exec.run();
exec.debugger_stop_cpu_hook();
}
// adjust for any cycles we took back
/*assert(ran >= *exec->m_icountptr);*/
ran -= exec.icountptrRef.i;
/*assert(ran >= exec->m_cycles_stolen);*/
ran -= exec.cycles_stolen;
profiler_global.g_profiler.stop();
}
// account for these cycles
exec.totalcycles += (UInt64)ran;
// update the local time for this CPU
attotime deltatime;
if (ran < exec.cycles_per_second)
{
deltatime = new attotime(0, exec.attoseconds_per_cycle * ran);
}
else
{
UInt32 remainder;
int secs = (int)divu_64x32_rem((UInt64)ran, exec.cycles_per_second, out remainder);
deltatime = new attotime(secs, remainder * exec.attoseconds_per_cycle);
}
assert(deltatime >= attotime.zero);
exec.localtime += deltatime;
if (machine().video().frame_update_count() % 100 == 0)
{
LOG("device_scheduler.timeslice() - {0} ran, {1} total, time = {2}\n", ran, exec.totalcycles, exec.localtime.as_string());
}
// if the new local CPU time is less than our target, move the target up, but not before the base
if (exec.localtime < target)
{
target = attotime.Max(exec.localtime, m_basetime);
if (machine().video().frame_update_count() % 1000 == 0)
{
LOG("device_scheduler.timeslice() - (new target)\n");
}
}
}
}
}
m_executing_device = null;
// update the base time
m_basetime = target;
}
// execute timers
execute_timers();
}