# StructPollfd

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  
Summary:[Fields](https://developer.android.com/reference/android/system/StructPollfd#lfields)\|[Ctors](https://developer.android.com/reference/android/system/StructPollfd#pubctors)\|[Methods](https://developer.android.com/reference/android/system/StructPollfd#pubmethods)\|[Inherited Methods](https://developer.android.com/reference/android/system/StructPollfd#inhmethods)  

# StructPollfd

*** ** * ** ***

[Kotlin](https://developer.android.com/reference/kotlin/android/system/StructPollfd "View this page in Kotlin")\|Java

`
public

final

class
StructPollfd
`  
`

extends `[Object](https://developer.android.com/reference/java/lang/Object)`


``


`

|---|-----------------------------|
| [java.lang.Object](https://developer.android.com/reference/java/lang/Object) ||
| ↳ | android.system.StructPollfd |

<br />

*** ** * ** ***

Used as an in/out parameter to[Os.poll](https://developer.android.com/reference/android/system/Os#poll(android.system.StructPollfd[],%20int)). Corresponds to C's`struct pollfd`from`<poll.h>`.

## Summary

|                                                                                                                                        ### Fields                                                                                                                                        ||
|--------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| ` public short`                                                                            | [events](https://developer.android.com/reference/android/system/StructPollfd#events) The events we're interested in.                                                                         |
| ` public `[FileDescriptor](https://developer.android.com/reference/java/io/FileDescriptor) | [fd](https://developer.android.com/reference/android/system/StructPollfd#fd) The file descriptor to poll.                                                                                    |
| ` public short`                                                                            | [revents](https://developer.android.com/reference/android/system/StructPollfd#revents) The events that actually happened.                                                                    |
| ` public `[Object](https://developer.android.com/reference/java/lang/Object)               | [userData](https://developer.android.com/reference/android/system/StructPollfd#userData) A non-standard extension that lets callers conveniently map back to the object their fd belongs to. |

|                                            ### Public constructors                                            ||
|------------------------------------------------------------------------------------------------------------|---|
| ` `[StructPollfd](https://developer.android.com/reference/android/system/StructPollfd#StructPollfd())`() ` |

|                                                                                                    ### Public methods                                                                                                    ||
|-----------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------|
| ` `[String](https://developer.android.com/reference/java/lang/String) | ` `[toString](https://developer.android.com/reference/android/system/StructPollfd#toString())`() ` Returns a string representation of the object. |

| ### Inherited methods |
|-----------------------|---|
| From class` `[java.lang.Object](https://developer.android.com/reference/java/lang/Object)` ` |--------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | ` `[Object](https://developer.android.com/reference/java/lang/Object)          | ` `[clone](https://developer.android.com/reference/java/lang/Object#clone())`() ` Creates and returns a copy of this object.                                                                                                                                                      | | ` boolean`                                                                     | ` `[equals](https://developer.android.com/reference/java/lang/Object#equals(java.lang.Object))`(`[Object](https://developer.android.com/reference/java/lang/Object)` obj) ` Indicates whether some other object is "equal to" this one.                                           | | ` void`                                                                        | ` `[finalize](https://developer.android.com/reference/java/lang/Object#finalize())`() ` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.                                                          | | ` final `[Class](https://developer.android.com/reference/java/lang/Class)`<?>` | ` `[getClass](https://developer.android.com/reference/java/lang/Object#getClass())`() ` Returns the runtime class of this`Object`.                                                                                                                                                | | ` int`                                                                         | ` `[hashCode](https://developer.android.com/reference/java/lang/Object#hashCode())`() ` Returns a hash code value for the object.                                                                                                                                                 | | ` final void`                                                                  | ` `[notify](https://developer.android.com/reference/java/lang/Object#notify())`() ` Wakes up a single thread that is waiting on this object's monitor.                                                                                                                            | | ` final void`                                                                  | ` `[notifyAll](https://developer.android.com/reference/java/lang/Object#notifyAll())`() ` Wakes up all threads that are waiting on this object's monitor.                                                                                                                         | | ` `[String](https://developer.android.com/reference/java/lang/String)          | ` `[toString](https://developer.android.com/reference/java/lang/Object#toString())`() ` Returns a string representation of the object.                                                                                                                                            | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long,%20int))`(long timeoutMillis, int nanos) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed. | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait(long))`(long timeoutMillis) ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*, or until a certain amount of real time has elapsed.                   | | ` final void`                                                                  | ` `[wait](https://developer.android.com/reference/java/lang/Object#wait())`() ` Causes the current thread to wait until it is awakened, typically by being*notified* or*interrupted*.                                                                                             | ||

## Fields

### events

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public short events
```

The events we're interested in. POLLIN corresponds to being in select(2)'s read fd set, POLLOUT to the write fd set.

<br />

### fd

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public FileDescriptor fd
```

The file descriptor to poll.

<br />

### revents

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public short revents
```

The events that actually happened.

<br />

### userData

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public Object userData
```

A non-standard extension that lets callers conveniently map back to the object their fd belongs to. This is used by Selector, for example, to associate each FileDescriptor with the corresponding SelectionKey.

<br />

## Public constructors

### StructPollfd

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public StructPollfd ()
```

<br />

<br />

## Public methods

### toString

Added in[API level 21](https://developer.android.com/guide/topics/manifest/uses-sdk-element#ApiLevels)  

```
public String toString ()
```

Returns a string representation of the object.

<br />

|                                                      Returns                                                      ||
|--------------------------------------------------------------------|-----------------------------------------------|
| [String](https://developer.android.com/reference/java/lang/String) | a string representation of the object. <br /> |