public virtual void ServiceTasks(uint curTicks, LinkTaskKind taskAction)
{
}
public override void ServiceTasks(uint curTicks, LinkTaskKind taskAction)
{
IsoTask t, s;
int h, j, k, ioIndex;
byte r;
bool checkSchedule = false, checkRemove = false;
uint elapsedTicks;
if (NumTasks == 0)
{
return;
}
if (taskAction == LinkTaskKind.Reset)
{
ResetLinkTasks();
return;
}
elapsedTicks = curTicks - LastIsoUpdateTicks;
LastIsoUpdateTicks = curTicks;
for (k = 0; k < NumTasks; k++)
{
t = IsoTasks[IsoTaskQueue[k]];
if (elapsedTicks >= t.msTicksRelativeToGo) // Perform this task.
{
do
{
bool isIsoMsg = (t.cmd == ProtocolConstants.MEDIATOR_DEVICE_ISOMSG);
if (isIsoMsg)
{
ioIndex = CopyMessage(t.ioIndex, 0);
if (ioIndex == -1)
{
break;
}
}
else
{
ioIndex = t.ioIndex;
}
MessageTransaction bmc = new MessageTransaction(Manager);
j = bmc.StartMessageTransaction(t.ioIndex);
if (j != 0)
{
break;
}
bmc.TaskCmd = (byte)t.cmd;
j = t.ownerDriver.CommandHandler(bmc);
if (j != 0)
{
break;
}
// Make a copy before its finalised.
if (!isIsoMsg)
{
byte pktLen = (byte)(ProtocolConstants.GENERAL_OVERHEADS_SIZE + bmc.MsgBuffer.dataLength());
ioIndex = CopyMessage(t.ioIndex, pktLen);
if (ioIndex == -1)
{
break;
}
t.ioIndex = ioIndex;
bmc.ReturnCmd = bmc.TaskCmd;
}
bmc.FinishMessageTransaction();
} while(false);
// Check if task to be removed.
if (t.repeatCount > 0)
{
if (--t.repeatCount == 0)
{
// Free message buffer.
Manager.IoBuffersFreeHeap.Release(t.ioIndex);
t.ioIndex = -1;
// Mark task for later removal.
t.state = IsoRemove;
checkRemove = true;
}
}
if ((t.state & IsoRemove) == 0)
{
// Mark task as requiring rescheduling.
t.state |= IsoReschedule;
checkSchedule = true;
}
// Update elapsedTicks:
elapsedTicks -= t.msTicksRelativeToGo;
}
else
{
t.msTicksRelativeToGo -= elapsedTicks;
break;
}
}
if (checkRemove)
{
r = 0;
for (k = 0; k < NumTasks; k++)
{
j = IsoTaskQueue[k];
if (IsoTasks[j].ioIndex != -1)
{
IsoTaskQueue[r++] = j;
}
}
NumTasks = r;
}
if (checkSchedule) // Reschedule tasks.
{
for (j = 0; j < NumTasks; j++) // Find first task that doesn't require rescheduling.
{
if ((IsoTasks[IsoTaskQueue[j]].state & IsoReschedule) == 0)
{
break;
}
}
for (k = j - 1; k >= 0; k--)
{
t = IsoTasks[IsoTaskQueue[k]];
t.state = 0;
t.msTicksRelativeToGo = t.msInterval - 1; // Note, minus one because 1 tick used during scheduling.
r = (byte)k;
do // Ripple current task down Q until position found.
{
if ((r + 1) == NumTasks) // Check next not past end.
{
break;
}
s = IsoTasks[IsoTaskQueue[r + 1]];
if (t.msTicksRelativeToGo < s.msTicksRelativeToGo) // '<' for fairness.
{
s.msTicksRelativeToGo -= t.msTicksRelativeToGo;
break;
}
// Find location deeper in schedule.
t.msTicksRelativeToGo -= s.msTicksRelativeToGo;
// Swap over tasks in Q.
h = IsoTaskQueue[r];
IsoTaskQueue[r] = IsoTaskQueue[r + 1];
IsoTaskQueue[r + 1] = h;
++r;
} while(r < NumTasks);
if (k == 0)
{
break;
}
}
}
}