Hardware wake-and-go mechanism and content addressable memory with instruction pre-fetch look-ahead to detect programming idioms

Abstract

A hardware wake-and-go mechanism is provided for a data processing system. The wake-and-go mechanism looks ahead in the instruction stream of a thread for programming idioms that indicates that the thread is waiting for an event. The wake-and-go mechanism updates a wake-and-go array with a target address associated with the event for each recognized programming idiom. When the thread reaches a programming idiom, the thread goes to sleep until the event occurs. The wake-and-go array may be a content addressable memory (CAM). When a transaction appears on the symmetric multiprocessing (SMP) fabric that modifies the value at a target address in the CAM, the CAM returns a list of storage addresses at which the target address is stored. The wake-and-go mechanism associates these storage addresses with the threads waiting for an event at the target addresses, and may wake the one or more threads waiting for the event.