# spin_mutex Class

Summary

Class that models Mutex Concept using a spin lock.

## Syntax

    class spin_mutex;

## Header

    #include "tbb/spin_mutex.h"

## Description

A `spin_mutex` models the Mutex Concept. A `spin_mutex` is not scalable, fair, or recursive. It is ideal when the lock is lightly contended and is held for only a few machine instructions. If a thread has to wait to acquire a `spin_mutex`, it busy waits, which can degrade system performance if the wait is long. However, if the wait is typically short, a `spin_mutex` significantly improve performance compared to other mutexes.

## Members

See Mutex Concept.

Parent topic: Mutexes

## See Also

Mutext Concept