private static void Exec()
{
if (top != null)
{
// determine amount of jobs
BackgroundFb next = top.next;
int amount = 1;
while (next != null)
{
amount++;
next = next.next;
}
// execute this amount of jobs
// if jobs are added during execution of this jobs then
// these jobs are executed in a next cycle
while (top != null && amount != 0)
{
BackgroundFb current = top;
lock (worker)
{
BackgroundFb temp = top; // remember top object to set top.next to null
top = top.next; // next job
temp.next = null;
}
amount--;
current.Exec(); // execute job
}
}
}
internal static bool AddJob(BackgroundFb fb)
{
bool result = false;
if (Resource.Running)
{
if (fb != null)
{
fb.Exec();
result = true;
}
}
else
{
lock (worker)
{
if (top == null)
{
top = fb;
}
else
{
bool bBreak = false;
BackgroundFb iter = top;
while (iter.next != null)
{
if (iter.next == fb)
{
// an object is allowed to exist only once in the queue
bBreak = true;
break;
}
iter = iter.next;
}
if (!bBreak)
{
if (iter != fb) // avoid recursion in chain (important if top.next == null)
{
iter.next = fb;
result = true;
}
}
}
}
}
return(result);
}
