---
name: "dtk_nanosleep"
section: "3"
platform: "linux"
package: "libdrawtk-dev"
version: "2.0-2.1"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/dtk_nanosleep"
---

# dtk\_nanosleep(3)

high-resolution sleep

## NAME

dtk\_nanosleep - high-resolution sleep

## SYNOPSIS

**#include \<dtk\_time.h\>**

**int dtk\_nanosleep(int** *abs***, const struct dtk\_timespec\*** *req***,**\
                            **struct dtk\_timespec\*** *rem***);**\

## DESCRIPTION

The function **dtk\_nanosleep**() allows the caller to sleep for an interval with nanosecond precision. If the argument *abs* is zero, the specified interval is interpretated as a relative value, otherwise an absolute value. The interval is specified by the *req* argument which is a pointer to a dtk\_timespec structure defined as:

```
struct dtk_timespec {
    long sec;    /* seconds */
    long nsec;   /* nanoseconds */
};
```

If interpreted as an absolute value, it represents seconds and nanoseconds since the Epoch, 1970-01-01 00:00:00 +0000  (UTC).

**dtk\_nanosleep**() suspends the execution of the calling thread until either at least the time specified by *req* has elapsed, or a signal is delivered that causes a signal handler to be called or that terminates the process.

If the call is interrupted by a signal handler, **dtk\_nanosleep**() returns -1, and sets *errno* to **EINTR**. In addition, if *rem* is not NULL, and *abs* is zero, it returns the remaining unslept time in *rem*. This value can then be used to call **dtk\_nanosleep**() again and complete a (relative) sleep.

## RETURN VALUE

On successfully sleeping for the requested interval, **dtk\_nanosleep**() returns 0. If the call is interrupted by a signal handler or encounters an error, then it returns -1 and *errno* is set appropriately.

## ERRORS

**dtk\_nanosleep**() will fail if:

- **EINTR**

  The sleep was interrupted by a signal handler.

- **EINVAL**

  The value in the *nsec* field was not in the range 0 to 999999999 or *sec* was negative.

## NOTE

This function is a wrapper to [**clock\_nanosleep**(2)](/clock_nanosleep/2.md) if it is provided by the system. Otherwise, it implements the function by using the sleep function with the highest precision available on the system.

## SEE ALSO

[**dtk\_nanosleep**(3)](/dtk_nanosleep/3.md), [**clock\_nanosleep**(2)](/clock_nanosleep/2.md)