>The code is totally and irrecoverably broken (from a threading perspective). >There is no way to fix it if it has to retain its current form.
Well... let's take the example of an interruptible task. We have a main program which launches a thread.
Now, we want to stop this thread. We can use interruption or the following code:

T1:
while(true)
{
lock lk(mutex);
if (end) break;
/* dosomething */
}
T2:
interruptT1()
{
lock lk(mutex);
end = true;
}
>The basic idea when using threads is to create parallelism. Thread T1 is >inherently non-parallel. It simply cannot operate in parallel with anyone >else who also needs to access the shared state that is protected by the >mutex.

That's what I call contention (when your threads work in a collaborative way)...

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