CSC/ECE 506 Spring 2010/Ch 9/Synchronization

Hardware Support For Synchronization

Hardware Implementations

Hardware implementations for synchronization traditionally include locks, barriers, and mutual exclusion. These types of hardware synchronizations use a method called busy-waiting, or spinning which prevents threads from continuing to execute. Spinning simply means that a thread continuously checks if it is okay to continue (threads are usually competing with each other). This technique is implemented in hardware through mutexes or semaphore, which prevent multiple processes from being accessed at the same time.

Atomic instructions, which are support by the processor Instruction Set Architecture(ISA), are typically used for hardware synchronizations. Some of these atomic instructions include: Test-and-Set, Fetch-and-Increment, Test-and- Test-and-Set.