FYI, waiting for a condition variable can cause a thread to enter a wait state that's interruptible, in theory, but the mechanism is different since condition variables and SRW locks are pointer-sized values in user space, instead of NT objects in kernel space. The current implementation is based on the system call NtWaitForAlertByThreadId(address, timeout), which enters the "WrAlertByThreadId" wait state. The address parameter is that of the SRW lock. The kernel sets this as the 'object' for the wait, but the wait is actually satisfied by alerting the thread directly via NtAlertThreadByThreadId(tid). ISTM, they could have added a function that calls the latter to cancel a wait on a given thread. That would have been useful for Ctrl+C since the handler executes on a new thread.