---
title: "thread_sleep()"
description: "Sure! Here’s the revised answer with POSIX context in the description and note:"
url: "https://wasix.org/docs/api-reference/wasix/thread_sleep/"
markdown: "https://wasix.org/docs/api-reference/wasix/thread_sleep.md"
---

Sure! Here’s the revised answer with POSIX context in the description and note:

# `thread_sleep()`

Sends the current thread to sleep for a period of time.

## Description

The `thread_sleep()` function suspends the execution of the current thread for a specified duration, allowing other threads to execute during the sleep period. This function is used to introduce delays or pause the execution of a thread for a certain amount of time.

This function is similar to the POSIX `pthread_sleep()` function, which suspends the execution of a thread for a specified period.

## Syntax

```ebnf
  ;;; Sends the current thread to sleep for a period of time
  (@interface func (export "thread_sleep")
    ;;; Amount of time that the thread should sleep
    (param $duration $timestamp)
    (result $error (expected (error $errno)))
  )
```

## Parameters

- `ctx`: A mutable reference to the function environment.
- `duration`: The amount of time that the thread should sleep, specified in milliseconds.

## Return Value

The function returns `Ok(Errno::Success)` if the sleep operation is successful. Otherwise, it returns an `Errno` value indicating the reason for the failure.

## Logging

This function is instrumented with `debug` level logging.

## Note

- The `thread_sleep()` function suspends the execution of the current thread for a specified duration, allowing other threads to execute during the sleep period.
- The `duration` parameter specifies the amount of time in milliseconds that the thread should sleep.
- Sleeping a thread can be useful in scenarios where you want to introduce delays, implement time-based operations, or yield the CPU to other threads or processes.
- The `thread_sleep()` function is similar to the POSIX `pthread_sleep()` function, which suspends the execution of a thread for a specified period.
- It’s important to note that the actual sleep duration may vary due to factors such as system load and scheduling policies.
- Sleeping a thread is a non-busy-waiting method that allows the thread to relinquish the CPU and avoid unnecessary resource consumption.
- The `thread_sleep()` function provides a simple way to introduce delays or pause the execution of a thread for a specified period of time in the WASI environment.
- Care should be taken when using `thread_sleep()` in performance-critical applications, as it may impact overall application responsiveness and throughput.
- It’s recommended to use sleep operations judiciously and consider alternative synchronization and coordination mechanisms if precise timing or responsiveness is required.
- Properly managing thread synchronization and coordination is essential to ensure correct behavior and avoid race conditions or other synchronization issues in multi-threaded applications.

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