Patent ID: 7426732

Claim:
A method in a computer system for placing a task in a known state, the computer system having an operating system, the task having multiple threads executing on streams of a processor of the computer system, the processor having multiple streams for simultaneously executing threads of the task, the method comprising: under control of the operating system, notifying each of the threads of the task executing on a stream of the processor to enter a known state, the known state being an active state in which the thread is not making productive use of the processor; for each of the threads, in response to receiving the notification, entering the known state so that an action can be performed with the task being in the known state, and notifying a designated thread of the task that the thread has entered a known state; and under control of the designated thread, determining whether a notification has been received from each of the other threads of the task, and when it is determined that a notification has been received from each of the other threads of the task, notifying the operating system that the task is now in the known state.