# PRLinger

Structure used with the `PR_SockOpt_Linger` socket option to specify
the time interval (in {ref}`PRIntervalTime` units) to linger on closing a
socket if any data remain in the socket send buffer.

## Syntax

```{code}
#include <prio.h>

typedef struct PRLinger {
  PRBool polarity;
  PRIntervalTime linger;
} PRLinger;
```

## Fields

The structure has the following fields:

`polarity`

: Polarity of the option's setting: `PR_FALSE` means the option is
  off, in which case the value of `linger` is ignored. `PR_TRUE`
  means the option is on, and the value of `linger` will be used to
  determine how long {ref}`PR_Close` waits before returning.

`linger`

: Time (in {ref}`PRIntervalTime` units) to linger before closing if any
  data remain in the socket send buffer.

## Description

By default, {ref}`PR_Close` returns immediately, but if there are any data
remaining in the socket send buffer, the system attempts to deliver the
data to the peer. The `PR_SockOpt_Linger` socket option, with a value
represented by a structure of type {ref}`PRLinger`, makes it possible to
change this default as follows:

- If `polarity` is set to `PR_FALSE`, {ref}`PR_Close` returns
  immediately, but if there are any data remaining in the socket send
  buffer, the runtime attempts to deliver the data to the peer.
- If `polarity` is set to `PR_TRUE` and `linger` is set to 0
  (`PR_INTERVAL_NO_WAIT`), the runtime aborts the connection when it
  is closed and discards any data remaining in the socket send buffer.
- If `polarity` is set to `PR_TRUE` and `linger` is nonzero, the
  runtime *lingers* when the socket is closed. That is, if any data
  remains in the socket send buffer, {ref}`PR_Close` blocks until either
  all the data is sent and acknowledged by the peer or the interval
  specified by `linger` expires.