## Function: SB-THREAD:HOLDING-MUTEX-P [![package](https://img.shields.io/badge/Package-SB--THREAD-5f9ea0.svg?style=social&colorA=999999)](../) [![type](https://img.shields.io/badge/Type-Function-5f9ea0.svg?style=social&colorA=999999)](../#function) [![github](https://img.shields.io/badge/GitHub-View_the_source-5f9ea0.svg?style=social&colorA=999999&logo=github)](https://github.com/sbcl/sbcl/blob/master/src/code/thread.lisp/) > Test whether the current thread is holding MUTEX. ### Lambda list ```cl (sb-thread:mutex) ```