1# sleep.h 2 3 4## Overview 5 6The **sleep.h** file declares the sleep and yield interfaces in C. 7 8**Since**: 10 9 10**Related module**: [FFRT](_f_f_r_t.md) 11 12 13## Summary 14 15 16### Functions 17 18| Name| Description| 19| -------- | -------- | 20| FFRT_C_API int [ffrt_usleep](_f_f_r_t.md#ffrt_usleep) (uint64_t usec) | Suspends the calling thread for a given duration. | 21| FFRT_C_API void [ffrt_yield](_f_f_r_t.md#ffrt_yield) (void) | Passes control to other tasks so that they can be executed. | 22