# pollfd
## **Overview**
**Related Modules:**
[IO](zh-cn_topic_0000001054799545.md)
**Description:**
Defines I/O multiplexing.
This structure is used to describe the content during I/O multiplexing, including the file descriptor, event mask, and returned event mask.
## **Summary**
## Data Fields
## **Details**
## **Field Documentation**
## events
```
short pollfd::events
```
**Description:**
Event mask to be queried
## fd
```
int pollfd::fd
```
**Description:**
File descriptor
## revents
```
short pollfd::revents
```
**Description:**
Returned event mask