---
name: "io_uring_prep_poll_add"
section: "3"
platform: "linux"
package: "liburing"
version: "2.15-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/io_uring_prep_poll_add"
---

# io\_uring\_prep\_poll\_add(3)

prepare a poll request

## NAME

io\_uring\_prep\_poll\_add - prepare a poll request

## SYNOPSIS

```
#include <poll.h>
#include <liburing.h>
```

**void io\_uring\_prep\_poll\_add(struct io\_uring\_sqe \****sqe***,**                             **int** *fd***,**                             **unsigned** *poll\_mask***);**

**void io\_uring\_prep\_poll\_multishot(struct io\_uring\_sqe \****sqe***,**                                   **int** *fd***,**                                   **unsigned** *poll\_mask***);**

## DESCRIPTION

The [**io\_uring\_prep\_poll\_add**(3)](/io_uring_prep_poll_add/3.md) function prepares a poll request. The submission queue entry *sqe* is setup to use the file descriptor *fd* that should get polled, with the events desired specified in the *poll\_mask* argument.

The default behavior is a single-shot poll request. When the specified event has triggered, a completion CQE is posted and no more events will be generated by the poll request. [**io\_uring\_prep\_poll\_multishot**(3)](/io_uring_prep_poll_multishot/3.md) behaves identically in terms of events, but it persists across notifications and will repeatedly post notifications for the same registration. A CQE posted from a multishot poll request will have **IORING\_CQE\_F\_MORE** set in the CQE *flags* member, indicating that the application should expect more completions from this request. If the multishot poll request gets terminated or experiences an error, this flag will not be set in the CQE. If this happens, the application should not expect further CQEs from the original request and must reissue a new one if it still wishes to get notifications on this file descriptor.

## RETURN VALUE

None

## ERRORS

The CQE *res* field will contain the result of the operation, which is a bitmask of the events notified. See the [**poll**(2)](/poll/2.md) man page for details. Note that where synchronous system calls will return **-1** on failure and set *errno* to the actual error value, io\_uring never uses *errno*. Instead it returns the negated *errno* directly in the CQE *res* field.

## SEE ALSO

[**io\_uring\_get\_sqe**(3)](/io_uring_get_sqe/3.md), [**io\_uring\_submit**(3)](/io_uring_submit/3.md), [**poll**(2)](/poll/2.md), **epoll\_ctl**(3)